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Da Silva DE, Richards CM, McRae SA, Riar I, Yang S(S, Zurfluh NE, Gibon J, Klegeris A. Extracellular mixed histones are neurotoxic and modulate select neuroimmune responses of glial cells. PLoS One 2024; 19:e0298748. [PMID: 38630734 PMCID: PMC11023449 DOI: 10.1371/journal.pone.0298748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 01/29/2024] [Indexed: 04/19/2024] Open
Abstract
Although histone proteins are widely known for their intranuclear functions where they organize DNA, all five histone types can also be released into the extracellular space from damaged cells. Extracellular histones can interact with pattern recognition receptors of peripheral immune cells, including toll-like receptor 4 (TLR4), causing pro-inflammatory activation, which indicates they may act as damage-associated molecular patterns (DAMPs) in peripheral tissues. Very limited information is available about functions of extracellular histones in the central nervous system (CNS). To address this knowledge gap, we applied mixed histones (MH) to cultured cells modeling neurons, microglia, and astrocytes. Microglia are the professional CNS immunocytes, while astrocytes are the main support cells for neurons. Both these cell types are critical for neuroimmune responses and their dysregulated activity contributes to neurodegenerative diseases. We measured effects of extracellular MH on cell viability and select neuroimmune functions of microglia and astrocytes. MH were toxic to cultured primary murine neurons and also reduced viability of NSC-34 murine and SH-SY5Y human neuron-like cells in TLR4-dependent manner. MH did not affect the viability of resting or immune-stimulated BV-2 murine microglia or U118 MG human astrocytic cells. When applied to BV-2 cells, MH enhanced secretion of the potential neurotoxin glutamate, but did not modulate the release of nitric oxide (NO), tumor necrosis factor-α (TNF), C-X-C motif chemokine ligand 10 (CXCL10), or the overall cytotoxicity of lipopolysaccharide (LPS)- and/or interferon (IFN)-γ-stimulated BV-2 microglial cells towards NSC-34 neuron-like cells. We demonstrated, for the first time, that MH downregulated phagocytic activity of LPS-stimulated BV-2 microglia. However, MH also exhibited protective effect by ameliorating the cytotoxicity of LPS-stimulated U118 MG astrocytic cells towards SH-SY5Y neuron-like cells. Our data demonstrate extracellular MH could both damage neurons and alter neuroimmune functions of glial cells. These actions of MH could be targeted for treatment of neurodegenerative diseases.
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Affiliation(s)
- Dylan E. Da Silva
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Christy M. Richards
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Seamus A. McRae
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Ishvin Riar
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Sijie (Shirley) Yang
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Noah E. Zurfluh
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Julien Gibon
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, University Way, Kelowna, British Columbia, Canada
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2
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Rodríguez J, De Santis Arévalo J, Dennis VA, Rodríguez AM, Giambartolomei GH. Bystander activation of microglia by Brucella abortus-infected astrocytes induces neuronal death via IL-6 trans-signaling. Front Immunol 2024; 14:1343503. [PMID: 38322014 PMCID: PMC10844513 DOI: 10.3389/fimmu.2023.1343503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 12/29/2023] [Indexed: 02/08/2024] Open
Abstract
Inflammation plays a key role in the pathogenesis of neurobrucellosis where glial cell interactions are at the root of this pathological condition. In this study, we present evidence indicating that soluble factors secreted by Brucella abortus-infected astrocytes activate microglia to induce neuronal death. Culture supernatants (SN) from B. abortus-infected astrocytes induce the release of pro-inflammatory mediators and the increase of the microglial phagocytic capacity, which are two key features in the execution of live neurons by primary phagocytosis, a recently described mechanism whereby B. abortus-activated microglia kills neurons by phagocytosing them. IL-6 neutralization completely abrogates neuronal loss. IL-6 is solely involved in increasing the phagocytic capacity of activated microglia as induced by SN from B. abortus-infected astrocytes and does not participate in their inflammatory activation. Both autocrine microglia-derived and paracrine astrocyte-secreted IL-6 endow microglial cells with up-regulated phagocytic capacity that allows them to phagocytose neurons. Blocking of IL-6 signaling by soluble gp130 abrogates microglial phagocytosis and concomitant neuronal death, indicating that IL-6 activates microglia via trans-signaling. Altogether, these results demonstrate that soluble factors secreted by B. abortus-infected astrocytes activate microglia to induce, via IL-6 trans-signaling, the death of neurons. IL-6 signaling inhibition may thus be considered a strategy to control inflammation and CNS damage in neurobrucellosis.
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Affiliation(s)
- Julia Rodríguez
- Instituto de Inmunología, Genética y Metabolismo (INIGEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Julia De Santis Arévalo
- Instituto de Inmunología, Genética y Metabolismo (INIGEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Vida A Dennis
- Center for NanoBiotechnology Research and Department of Biological Sciences, Alabama State University, Montgomery, AL, United States
| | - Ana M Rodríguez
- Instituto de Inmunología, Genética y Metabolismo (INIGEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Guillermo H Giambartolomei
- Instituto de Inmunología, Genética y Metabolismo (INIGEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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3
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Rabbany JM, Fitzgerald K, Bowman J, Dong F, Neeki MM. Methamphetamine-induced encephalopathy in the absence of hyperammonemia. BMC Psychiatry 2023; 23:276. [PMID: 37081388 PMCID: PMC10120267 DOI: 10.1186/s12888-023-04764-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 04/09/2023] [Indexed: 04/22/2023] Open
Abstract
BACKGROUND Methamphetamine is an addictive drug with various effects on the neurotransmitters in the central nervous system. Methamphetamine-induced encephalopathy in the absence of hyperammonemia presents a unique challenge in a clinical setting. Previously published cases of methamphetamine-induced encephalopathy suggested that methamphetamine-induced hepatotoxicity and subsequent hyperammonemia may be the cause of encephalopathy. However, the literature is limited on methamphetamine-induced encephalopathy without hyperammonemia. CASE This case presents a disoriented patient with methamphetamine use disorder in acute toxicity, unable to ambulate independently, and poorly responsive to verbal stimuli. The patient was found to have normal ammonia levels. DISCUSSION This patient's presentation and laboratory findings, namely normal ammonia levels, suggest a different pathophysiological pathway for methamphetamine-induced encephalopathy. One potential pathway is through the direct action of methamphetamine on the central nervous system through acute disruption of neurotransmitter signaling and disruption of the blood-brain barrier. CONCLUSION Further research should be conducted into the prevalence and pathophysiology of methamphetamine-induced encephalopathy in the absence of hyperammonemia. KEY POINTS Methamphetamine-induced encephalopathy (MIE) in the absence of hyperammonemia presents a unique challenge in a clinical setting. Previously published cases of MIE suggest that methamphetamine-induced hepatotoxicity and subsequent hyperammonemia may be the cause of encephalopathy. Further research should be conducted into the prevalence and pathophysiology of MIE in the absence of hyperammonemia.
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Affiliation(s)
- Jessica M Rabbany
- Department of Behavioral Health, Arrowhead Regional Medical Center, Colton, CA, USA.
| | | | - Jade Bowman
- California University of Science and Medicine, Colton, CA, USA
| | - Fanglong Dong
- Department of Emergency Medicine, Arrowhead Regional Medical Center, Colton, CA, USA
| | - Michael M Neeki
- Department of Emergency Medicine, Arrowhead Regional Medical Center, Colton, CA, USA
- California University of Science and Medicine, Colton, CA, USA
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Yu M, Ou Y, Wang H, Gu W. PU.1 interaction with p50 promotes microglial-mediated inflammation in secondary spinal cord injury in SCI rats. Int J Neurosci 2023; 133:389-402. [PMID: 33970748 DOI: 10.1080/00207454.2021.1923017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Purpose/aim of the study Secondary spinal cord injury is the inflammatory damage to surrounding tissues caused by activated microglial-mediated neuroinflammatory responses. The nuclear factor-κB (p65/p50) pathway and PU.1 are closely correlated with inflammatory responses; thus, we examined the relationship and function between PU.1 and p50 in secondary spinal cord injury.Materials and methods In this study, we established an adult rat acute spinal cord injury model to simulate the pathological process of spinal cord injury.Results: We found that the expression of PU.1 was significantly increased at three days after spinal cord injury and mainly expressed in activated microglia. Moreover, p-p50 expression was increased in SCI rats and the protein interacted with PU.1. Lipopolysaccharide was used to induce microglia activation in vitro.Conclusions: The results showed that PU.1 and p-p50 expression was significantly increased and PU.1 interacted with p50 in the nucleus. The levels of tumor necrosis factor-α and interleukin-1β secreted by microglia were detected by enzyme-linked immunosorbent assay. The results showed that when both PU.1 and p50 were overexpressed, tumor necrosis factor-α and interleukin-1β secretion was significantly increased to levels higher than in cells overexpressing PU.1 or p50 alone. These results suggest that PU.1 and p50 interact to promote p65 transcription and the expression of inflammatory factors, which is an important mechanism of the microglial-mediated inflammatory response to secondary injury after spinal cord injury.
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Affiliation(s)
- Mingchen Yu
- Department of Orthopedics, Changzhou Seventh People's Hospital, Changzhou, Jiangsu Province, China.,Nantong University, Nantong, Jiangsu Province, China
| | - Yiqing Ou
- Nantong University, Nantong, Jiangsu Province, China.,The First People's Hospital of Foshan, Foshan, Guangdong Province, China
| | - Hongmei Wang
- Nantong University, Nantong, Jiangsu Province, China
| | - Weidong Gu
- Department of Orthopedics, Changzhou Seventh People's Hospital, Changzhou, Jiangsu Province, China
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Guha A, Husain MA, Si Y, Nabors LB, Filippova N, Promer G, Smith R, King PH. RNA regulation of inflammatory responses in glia and its potential as a therapeutic target in central nervous system disorders. Glia 2023; 71:485-508. [PMID: 36380708 DOI: 10.1002/glia.24288] [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: 08/17/2022] [Revised: 09/29/2022] [Accepted: 10/14/2022] [Indexed: 11/17/2022]
Abstract
A major hallmark of neuroinflammation is the activation of microglia and astrocytes with the induction of inflammatory mediators such as IL-1β, TNF-α, iNOS, and IL-6. Neuroinflammation contributes to disease progression in a plethora of neurological disorders ranging from acute CNS trauma to chronic neurodegenerative disease. Posttranscriptional pathways of mRNA stability and translational efficiency are major drivers for the expression of these inflammatory mediators. A common element in this level of regulation centers around the adenine- and uridine-rich element (ARE) which is present in the 3' untranslated region (UTR) of the mRNAs encoding these inflammatory mediators. (ARE)-binding proteins (AUBPs) such as Human antigen R (HuR), Tristetraprolin (TTP) and KH- type splicing regulatory protein (KSRP) are key nodes for directing these posttranscriptional pathways and either promote (HuR) or suppress (TTP and KSRP) glial production of inflammatory mediators. This review will discuss basic concepts of ARE-mediated RNA regulation and its impact on glial-driven neuroinflammatory diseases. We will discuss strategies to target this novel level of gene regulation for therapeutic effect and review exciting preliminary studies that underscore its potential for treating neurological disorders.
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Affiliation(s)
- Abhishek Guha
- Department Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Mohammed Amir Husain
- Department Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Ying Si
- Department Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
- Department Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - L Burt Nabors
- Department Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Natalia Filippova
- Department Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Grace Promer
- Department Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Reed Smith
- Department Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Peter H King
- Department Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
- Department Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
- Birmingham Department of Veterans Health Care System, Birmingham, Alabama, USA
- Center for Neurodegeneration and Experimental Therapeutics, The University of Alabama at Birmingham, Birmingham, USA
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6
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Korf JM, Honarpisheh P, Mohan EC, Banerjee A, Blasco-Conesa MP, Honarpisheh P, Guzman GU, Khan R, Ganesh BP, Hazen AL, Lee J, Kumar A, McCullough LD, Chauhan A. CD11b high B Cells Increase after Stroke and Regulate Microglia. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 209:288-300. [PMID: 35732342 PMCID: PMC9446461 DOI: 10.4049/jimmunol.2100884] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 04/22/2022] [Indexed: 06/02/2023]
Abstract
Recent studies have highlighted the deleterious contributions of B cells to post-stroke recovery and cognitive decline. Different B cell subsets have been proposed on the basis of expression levels of transcription factors (e.g., T-bet) as well as specific surface proteins. CD11b (α-chain of integrin) is expressed by several immune cell types and is involved in regulation of cell motility, phagocytosis, and other essential functions of host immunity. Although B cells express CD11b, the CD11bhigh subset of B cells has not been well characterized, especially in immune dysregulation seen with aging and after stroke. Here, we investigate the role of CD11bhigh B cells in immune responses after stroke in young and aged mice. We evaluated the ability of CD11bhigh B cells to influence pro- and anti-inflammatory phenotypes of young and aged microglia (MG). We hypothesized that CD11bhigh B cells accumulate in the brain and contribute to neuroinflammation in aging and after stroke. We found that CD11bhigh B cells are a heterogeneous subpopulation of B cells predominantly present in naive aged mice. Their frequency increases in the brain after stroke in young and aged mice. Importantly, CD11bhigh B cells regulate MG phenotype and increase MG phagocytosis in both ex vivo and in vivo settings, likely by production of regulatory cytokines (e.g., TNF-α). As both APCs and adaptive immune cells with long-term memory function, B cells are uniquely positioned to regulate acute and chronic phases of the post-stroke immune response, and their influence is subset specific.
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Affiliation(s)
- Janelle M Korf
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
- University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX
| | - Pedram Honarpisheh
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
- University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX
| | - Eric C Mohan
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
| | - Anik Banerjee
- University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX
| | | | - Parisa Honarpisheh
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
| | - Gary U Guzman
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
| | - Romeesa Khan
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
| | - Bhanu P Ganesh
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
| | - Amy L Hazen
- University of Texas McGovern Medical School, Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, Houston, TX
| | - Juneyoung Lee
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
| | - Aditya Kumar
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
| | - Louise D McCullough
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX
| | - Anjali Chauhan
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX;
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Agmatine Mitigates Inflammation-Related Oxidative Stress in BV-2 Cells by Inducing a Pre-Adaptive Response. Int J Mol Sci 2022; 23:ijms23073561. [PMID: 35408922 PMCID: PMC8998340 DOI: 10.3390/ijms23073561] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/19/2022] [Accepted: 03/21/2022] [Indexed: 12/13/2022] Open
Abstract
Neuroinflammation and microglial activation, common components of most neurodegenerative diseases, can be imitated in vitro by challenging microglia cells with Lps. We here aimed to evaluate the effects of agmatine pretreatment on Lps-induced oxidative stress in a mouse microglial BV-2 cell line. Our findings show that agmatine suppresses nitrosative and oxidative burst in Lps-stimulated microglia by reducing iNOS and XO activity and decreasing O2- levels, arresting lipid peroxidation, increasing total glutathione content, and preserving GR and CAT activity. In accordance with these results, agmatine suppresses inflammatory NF-kB, and stimulates antioxidant Nrf2 pathway, resulting in decreased TNF, IL-1 beta, and IL-6 release, and reduced iNOS and COX-2 levels. Together with increased ARG1, CD206 and HO-1 levels, our results imply that, in inflammatory conditions, agmatine pushes microglia towards an anti-inflammatory phenotype. Interestingly, we also discovered that agmatine alone increases lipid peroxidation end product levels, induces Nrf2 activation, increases total glutathione content, and GPx activity. Thus, we hypothesize that some of the effects of agmatine, observed in activated microglia, may be mediated by induced oxidative stress and adaptive response, prior to Lps stimulation.
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8
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Complement System in Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms222413647. [PMID: 34948444 PMCID: PMC8705098 DOI: 10.3390/ijms222413647] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/10/2021] [Accepted: 12/15/2021] [Indexed: 01/02/2023] Open
Abstract
Alzheimer’s disease is a type of dementia characterized by problems with short-term memory, cognition, and difficulties with activities of daily living. It is a progressive, neurodegenerative disorder. The complement system is an ancient part of the innate immune system and comprises of more than thirty serum and membrane-bound proteins. This system has three different activating pathways and culminates into the formation of a membrane attack complex that ultimately causes target cell lysis (usually pathogens) The complement system is involved in several important functions in the central nervous system (CNS) that include neurogenesis, synaptic pruning, apoptosis, and neuronal plasticity. Here, we discuss how the complement system is involved in the effective functioning of CNS, while also contributing to chronic neuroinflammation leading to neurodegenerative disorders such as Alzheimer’s disease. We also discuss potential targets in the complement system for stopping its harmful effects via neuroinflammation and provide perspective for the direction of future research in this field.
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Canedo T, Portugal CC, Socodato R, Almeida TO, Terceiro AF, Bravo J, Silva AI, Magalhães JD, Guerra-Gomes S, Oliveira JF, Sousa N, Magalhães A, Relvas JB, Summavielle T. Astrocyte-derived TNF and glutamate critically modulate microglia activation by methamphetamine. Neuropsychopharmacology 2021; 46:2358-2370. [PMID: 34400780 PMCID: PMC8581027 DOI: 10.1038/s41386-021-01139-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/12/2021] [Accepted: 07/24/2021] [Indexed: 02/06/2023]
Abstract
Methamphetamine (Meth) is a powerful illicit psychostimulant, widely used for recreational purposes. Besides disrupting the monoaminergic system and promoting oxidative brain damage, Meth also causes neuroinflammation, contributing to synaptic dysfunction and behavioral deficits. Aberrant activation of microglia, the largest myeloid cell population in the brain, is a common feature in neurological disorders triggered by neuroinflammation. In this study, we investigated the mechanisms underlying the aberrant activation of microglia elicited by Meth in the adult mouse brain. We found that binge Meth exposure caused microgliosis and disrupted risk assessment behavior (a feature that usually occurs in individuals who abuse Meth), both of which required astrocyte-to-microglia crosstalk. Mechanistically, Meth triggered a detrimental increase of glutamate exocytosis from astrocytes (in a process dependent on TNF production and calcium mobilization), promoting microglial expansion and reactivity. Ablating TNF production, or suppressing astrocytic calcium mobilization, prevented Meth-elicited microglia reactivity and re-established risk assessment behavior as tested by elevated plus maze (EPM). Overall, our data indicate that glial crosstalk is critical to relay alterations caused by acute Meth exposure.
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Affiliation(s)
- Teresa Canedo
- grid.5808.50000 0001 1503 7226Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal ,grid.5808.50000 0001 1503 7226Faculdade de Medicina da Universidade do Porto (FMUP), Porto, Portugal
| | - Camila Cabral Portugal
- Glial Cell Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
| | - Renato Socodato
- grid.5808.50000 0001 1503 7226Glial Cell Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Tiago Oliveira Almeida
- grid.5808.50000 0001 1503 7226Glial Cell Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ana Filipa Terceiro
- grid.5808.50000 0001 1503 7226Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Joana Bravo
- grid.5808.50000 0001 1503 7226Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ana Isabel Silva
- grid.5808.50000 0001 1503 7226Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - João Duarte Magalhães
- grid.5808.50000 0001 1503 7226Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Sónia Guerra-Gomes
- grid.10328.380000 0001 2159 175XLife and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
| | - João Filipe Oliveira
- grid.10328.380000 0001 2159 175XLife and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal ,grid.10328.380000 0001 2159 175XICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal ,grid.410922.c0000 0001 0180 6901IPCA-EST-2Ai, Polytechnic Institute of Cávado and Ave, Applied Artificial Intelligence, Barcelos, Portugal
| | - Nuno Sousa
- grid.10328.380000 0001 2159 175XLife and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal ,grid.10328.380000 0001 2159 175XICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Ana Magalhães
- grid.5808.50000 0001 1503 7226Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - João Bettencourt Relvas
- grid.5808.50000 0001 1503 7226Faculdade de Medicina da Universidade do Porto (FMUP), Porto, Portugal ,grid.5808.50000 0001 1503 7226Glial Cell Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Teresa Summavielle
- Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde and IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal. .,ESS.PP, Escola Superior de Saúde do Politécnico do Porto, Porto, Portugal.
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10
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Pap R, Pandur E, Jánosa G, Sipos K, Agócs A, Deli J. Lutein Exerts Antioxidant and Anti-Inflammatory Effects and Influences Iron Utilization of BV-2 Microglia. Antioxidants (Basel) 2021; 10:antiox10030363. [PMID: 33673707 PMCID: PMC7997267 DOI: 10.3390/antiox10030363] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 12/12/2022] Open
Abstract
Lutein is a tetraterpene carotenoid, which has been reported as an important antioxidant and it is widely used as a supplement. Oxidative stress participates in many human diseases, including different types of neurodegenerative disorders. Microglia, the primary immune effector cells in the central nervous system, are implicated in these disorders by producing harmful substances such as reactive oxygen species (ROS). The protective mechanisms which scavenge ROS include enzymes and antioxidant substances. The protective effects of different carotenoids against oxidative stress have been described previously. Our study focuses on the effects of lutein on antioxidant enzymes, cytokines and iron metabolism under stress conditions in BV-2 microglia. We performed cell culture experiments: BV-2 cells were treated with lutein and/or with H2O2; the latter was used for inducing oxidative stress in microglial cells. Real-time PCR was performed for gene expression analyses of antioxidant enzymes, and ELISA was used for the detection of pro- and anti-inflammatory cytokines. Our results show that the application of lutein suppressed the H2O2-induced ROS (10′: 7.5 ng + 10 µM H2O2, p = 0.0002; 10 ng/µL + 10 µM H2O2, p = 0.0007), influenced iron utilization and changed the anti-inflammatory and pro-inflammatory cytokine secretions in BV-2 cells. Lutein increased the IL-10 secretions compared to control (24 h: 7.5 ng/µL p = 0.0274; 10 ng/µL p = 0.0008) and to 10 µM H2O2-treated cells (24 h: 7.5 ng/µL + H2O2, p = 0.0003; 10 ng/µL + H2O2, p = 0.0003), while it decreased the TNFα secretions compared to H2O2 treated cells (24 h: 7.5 ng/µL + H2O2, p < 0.0001; 10 ng/µL + H2O2, p < 0.0001). These results contribute to understanding the effects of lutein, which may help in preventing or suppressing ROS-mediated microglia activation, which is related to neuronal degeneration in oxidative stress scenario.
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Affiliation(s)
- Ramóna Pap
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Pécs, Rókus u. 2., H-7624 Pécs, Hungary; (R.P.); (E.P.); (G.J.); (K.S.)
| | - Edina Pandur
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Pécs, Rókus u. 2., H-7624 Pécs, Hungary; (R.P.); (E.P.); (G.J.); (K.S.)
| | - Gergely Jánosa
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Pécs, Rókus u. 2., H-7624 Pécs, Hungary; (R.P.); (E.P.); (G.J.); (K.S.)
| | - Katalin Sipos
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Pécs, Rókus u. 2., H-7624 Pécs, Hungary; (R.P.); (E.P.); (G.J.); (K.S.)
| | - Attila Agócs
- Department of Biochemistry and Medical Chemistry, Medical School, University of Pécs, Szigeti út 12., H-7624 Pécs, Hungary;
| | - József Deli
- Department of Biochemistry and Medical Chemistry, Medical School, University of Pécs, Szigeti út 12., H-7624 Pécs, Hungary;
- Department of Pharmacognosy, Faculty of Pharmacy, University of Pécs, Rókus u. 2., H-7624 Pécs, Hungary
- Correspondence:
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11
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Wiemann S, Reinhard J, Reinehr S, Cibir Z, Joachim SC, Faissner A. Loss of the Extracellular Matrix Molecule Tenascin-C Leads to Absence of Reactive Gliosis and Promotes Anti-inflammatory Cytokine Expression in an Autoimmune Glaucoma Mouse Model. Front Immunol 2020; 11:566279. [PMID: 33162981 PMCID: PMC7581917 DOI: 10.3389/fimmu.2020.566279] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/26/2020] [Indexed: 01/13/2023] Open
Abstract
Previous studies demonstrated that retinal damage correlates with a massive remodeling of extracellular matrix (ECM) molecules and reactive gliosis. However, the functional significance of the ECM in retinal neurodegeneration is still unknown. In the present study, we used an intraocular pressure (IOP) independent experimental autoimmune glaucoma (EAG) mouse model to examine the role of the ECM glycoprotein tenascin-C (Tnc). Wild type (WT ONA) and Tnc knockout (KO ONA) mice were immunized with an optic nerve antigen (ONA) homogenate and control groups (CO) obtained sodium chloride (WT CO, KO CO). IOP was measured weekly and electroretinographies were recorded at the end of the study. Ten weeks after immunization, we analyzed retinal ganglion cells (RGCs), glial cells, and the expression of different cytokines in retina and optic nerve tissue in all four groups. IOP and retinal function were comparable in all groups. Although RGC loss was less severe in KO ONA, WT as well as KO mice displayed a significant cell loss after immunization. Compared to KO ONA, less βIII-tubulin+ axons, and downregulated oligodendrocyte markers were noted in WT ONA optic nerves. In retina and optic nerve, we found an enhanced GFAP+ staining area of astrocytes in immunized WT. A significantly higher number of retinal Iba1+ microglia was found in WT ONA, while a lower number of Iba1+ cells was observed in KO ONA. Furthermore, an increased expression of the glial markers Gfap, Iba1, Nos2, and Cd68 was detected in retinal and optic nerve tissue of WT ONA, whereas comparable levels were observed in KO ONA. In addition, pro-inflammatory Tnfa expression was upregulated in WT ONA, but downregulated in KO ONA. Vice versa, a significantly increased anti-inflammatory Tgfb1 expression was measured in KO ONA animals. We conclude that Tnc plays an important role in glial and inflammatory response during retinal neurodegeneration. Our results provide evidence that Tnc is involved in glaucomatous damage by regulating retinal glial activation and cytokine release. Thus, this transgenic EAG mouse model for the first time offers the possibility to investigate IOP-independent glaucomatous damage in direct relation to ECM remodeling.
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Affiliation(s)
- Susanne Wiemann
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Jacqueline Reinhard
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr University Bochum, Bochum, Germany
| | - Zülal Cibir
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr University Bochum, Bochum, Germany
| | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
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12
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Raffaele S, Lombardi M, Verderio C, Fumagalli M. TNF Production and Release from Microglia via Extracellular Vesicles: Impact on Brain Functions. Cells 2020; 9:cells9102145. [PMID: 32977412 PMCID: PMC7598215 DOI: 10.3390/cells9102145] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
Tumor necrosis factor (TNF) is a pleiotropic cytokine powerfully influencing diverse processes of the central nervous system (CNS) under both physiological and pathological conditions. Here, we analyze current literature describing the molecular processes involved in TNF synthesis and release from microglia, the resident immune cells of the CNS and the main source of this cytokine both in brain development and neurodegenerative diseases. A special attention has been given to the unconventional vesicular pathway of TNF, based on the emerging role of microglia-derived extracellular vesicles (EVs) in the propagation of inflammatory signals and in mediating cell-to-cell communication. Moreover, we describe the contribution of microglial TNF in regulating important CNS functions, including the neuroinflammatory response following brain injury, the neuronal circuit formation and synaptic plasticity, and the processes of myelin damage and repair. Specifically, the available data on the functions mediated by microglial EVs carrying TNF have been scrutinized to gain insights on possible novel therapeutic strategies targeting TNF to foster CNS repair.
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Affiliation(s)
- Stefano Raffaele
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milan, Italy;
| | - Marta Lombardi
- CNR Institute of Neuroscience, 20129 Milan, Italy; (M.L.); (C.V.)
| | - Claudia Verderio
- CNR Institute of Neuroscience, 20129 Milan, Italy; (M.L.); (C.V.)
| | - Marta Fumagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milan, Italy;
- Correspondence: ; Tel.: +39-0250318307
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13
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Li Y, Ashraf U, Chen Z, Zhou D, Imran M, Ye J, Chen H, Cao S. Genome-wide profiling of host-encoded circular RNAs highlights their potential role during the Japanese encephalitis virus-induced neuroinflammatory response. BMC Genomics 2020; 21:409. [PMID: 32552669 PMCID: PMC7301528 DOI: 10.1186/s12864-020-06822-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/12/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Japanese encephalitis virus (JEV) is one of the common causes of acute encephalitis in humans. Japanese encephalitis is characterized by the uncontrolled release of inflammatory cytokines, which ultimately results in neuronal cell damage. In recent years, with the advancement of high-throughput sequencing technology, studies have shown that circRNAs, by competing with endogenous miRNAs, play a vital role in the pathology of CNS diseases. However, it is unknown whether circRNAs participate in JEV-induced neuroinflammation. RESULTS By employing Illumina RNA-sequencing, we identified 180 circRNAs and 58 miRNAs that showed significant differential expression in JEV-infected mice brain tissues. The functional enrichment analyses revealed that these differentially regulated circRNAs were predominantly related to neurotransmission, histone modifications, transcription misregulation, and inflammation-associated calcium signaling pathway. Our established competing endogenous RNA (ceRNA) interaction network suggested the correlation of several circRNAs, miRNAs, and mRNAs in regulating the inflammatory response during JEV infection. Among the predicted interactions, the correlation between circ_0000220, miR-326-3p, and BCL3/MK2/TRIM25 mRNAs was experimentally validated by knockdown or overexpression of the non-coding RNA entities in cultured mouse microglia. The knockdown of circ_0000220 or overexpression of miR-326-3p caused a lower production of JEV-induced inflammatory cytokines. CONCLUSIONS Conclusively, our study provides new insights into the host response to JEV infection and proposes the circRNA-targeting therapeutic interventions to rein in Japanese encephalitis.
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Affiliation(s)
- Yunchuan Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Usama Ashraf
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Zheng Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Dengyuan Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Muhammad Imran
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Jing Ye
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Shengbo Cao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China. .,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China. .,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
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14
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De Sousa Rodrigues ME, Houser MC, Walker DI, Jones DP, Chang J, Barnum CJ, Tansey MG. Targeting soluble tumor necrosis factor as a potential intervention to lower risk for late-onset Alzheimer's disease associated with obesity, metabolic syndrome, and type 2 diabetes. ALZHEIMERS RESEARCH & THERAPY 2019; 12:1. [PMID: 31892368 PMCID: PMC6937979 DOI: 10.1186/s13195-019-0546-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/16/2019] [Indexed: 02/08/2023]
Abstract
Background Insulin impairment and inflammation are two features common to type 2 diabetes and Alzheimer’s disease; however, the molecular and signaling interactions underlying this relationship are not well understood. Mounting evidence point to the associations between the disruption of metabolite processing in insulin impairment and neurodegenerative conditions such as Alzheimer’s. Although the brain depends partially on metabolites processed in the periphery, to date, little is known about how soluble tumor necrosis factor signaling (solTNF) impacts integrated peripheral immune and metabolic feedback signals in states of energy overload and insulin insensitivity. Methods C57Bl/6J mice were fed a high-fat high-carbohydrate diet (HFHC) for 14 weeks. The brain-permeant biologic XPro1595® was used to block solTNF-dependent pathways. Metabolic and immune alterations were evaluated in the gut, liver, and brain. Behavioral tests were performed. Untargeted metabolomics was carried out in the plasma and liver. Results HFHC diet promotes central insulin impairment and dysregulation of immune-modulatory gene expressed in the brain. Alteration of metabolites associated with type 2 diabetes and Alzheimer’s such as butanoate, glutamate, biopterin, branched-chain amino acids, purines, and proteoglycan metabolism was observed in HFHC-fed mice. solTNF inhibition ameliorates hepatic metabolic disturbances and hepatic and intestinal lipocalin-2 levels, and decreases insulin impairment in the brain and behavioral deficits associated with HFHC diet. Conclusions Our novel findings suggest that HFHC diet impacts central insulin signaling and immune-metabolic interactions in a solTNF-dependent manner to increase the risk for neurodegenerative conditions. Our novel findings indicate that selective solTNF neutralization can ameliorate peripheral and central diet-induced insulin impairment and identify lipocalin-2 as a potential target for therapeutic intervention to target inflammation and insulin disturbances in obesogenic environments. Collectively, our findings identify solTNF as a potential target for therapeutic intervention in inflammatory states and insulin disturbances in obesogenic environments to lower risk for AD.
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Affiliation(s)
| | - Madelyn C Houser
- Department of Physiology, School of Medicine at Emory University, 615 Michael Street, Atlanta, GA, 30322-3110, USA
| | - Douglas I Walker
- Division of Pulmonary, Allergy and Critical Care Medicine, Emory University Emory, 615 Michael Street, Atlanta, GA, 30322, USA.,Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, 10003, USA
| | - Dean P Jones
- Division of Pulmonary, Allergy and Critical Care Medicine, Emory University Emory, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Jianjun Chang
- Department of Physiology, School of Medicine at Emory University, 615 Michael Street, Atlanta, GA, 30322-3110, USA
| | - Christopher J Barnum
- Department of Physiology, School of Medicine at Emory University, 615 Michael Street, Atlanta, GA, 30322-3110, USA
| | - Malú G Tansey
- Department of Physiology, School of Medicine at Emory University, 615 Michael Street, Atlanta, GA, 30322-3110, USA. .,Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, FL, USA.
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15
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Glucagon-like peptide-1 suppresses neuroinflammation and improves neural structure. Pharmacol Res 2019; 152:104615. [PMID: 31881271 DOI: 10.1016/j.phrs.2019.104615] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 12/22/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is a hormone mainly secreted from enteroendocrine L cells. GLP-1 and its receptor are also expressed in the brain. GLP-1 signaling has pivotal roles in regulating neuroinflammation and memory function, but it is unclear how GLP-1 improves memory function by regulating neuroinflammation. Here, we demonstrated that GLP-1 enhances neural structure by inhibiting lipopolysaccharide (LPS)-induced inflammation in microglia with the effects of GLP-1 itself on neurons. Inflammatory secretions of BV-2 microglia by LPS aggravated mitochondrial function and cell survival, as well as neural structure in Neuro-2a neurons. In inflammatory condition, GLP-1 suppressed the secretion of tumor necrosis factor-alpha (TNF-α)-associated cytokines and chemokines in BV-2 microglia and ultimately enhanced neurite complexity (neurite length, number of neurites from soma, and secondary branches) in Neuro-2a neurons. We confirmed that GLP-1 improves neurite complexity, dendritic spine morphogenesis, and spine development in TNF-α-treated primary cortical neurons based on altered expression levels of the factors related to neurite growth and spine morphology. Given that our data that GLP-1 itself enhances neurite complexity and spine morphology in neurons, we suggest that GLP-1 has a therapeutic potential in central nervous system diseases.
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16
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García-Domínguez I, Veselá K, García-Revilla J, Carrillo-Jiménez A, Roca-Ceballos MA, Santiago M, de Pablos RM, Venero JL. Peripheral Inflammation Enhances Microglia Response and Nigral Dopaminergic Cell Death in an in vivo MPTP Model of Parkinson's Disease. Front Cell Neurosci 2018; 12:398. [PMID: 30459561 PMCID: PMC6232526 DOI: 10.3389/fncel.2018.00398] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/16/2018] [Indexed: 12/14/2022] Open
Abstract
The impact of systemic inflammation in nigral dopaminergic cell loss remains unclear. Here, we have investigated the role of peripheral inflammation induced by systemic lipopolysaccharide (LPS) administration in the MPTP-based model of Parkinson’s disease. Brain inflammation, microglia and astroglia activation, disruption of the blood–brain barrier (BBB) and integrity of the nigrostriatal dopaminergic system were evaluated in response to i.p. injection of LPS, MPTP or the combination of both. Our results showed that combinative treatment exacerbates microglia activation and enhances (i) the appearance of galectin-3-positive microglia, recently identified as microglial disease-associated phenotypic marker, (ii) the up-regulation of pro-inflammatory cytokines, (iii) the occurrence of A1 neurotoxic astrocytes, (iv) the breakdown of the BBB, and (v) the loss of dopaminergic neurons in the substantia nigra. Microglia activation was triggered earlier than other degenerative events, suggesting that over-activation of microglia (including different polarization states) may induce dopaminergic neuron loss by itself, initiating the endless cycle of inflammation/degeneration. Our study revitalizes the importance of peripheral inflammation as a potential risk factor for Parkinson’s disease and raises the possibility of using new anti-inflammatory therapies to improve the course of neurodegenerative diseases, including those directly aimed at modulating the deleterious activity of disease-associated microglia.
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Affiliation(s)
- Irene García-Domínguez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - Karolina Veselá
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - Juan García-Revilla
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - Alejandro Carrillo-Jiménez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - María Angustias Roca-Ceballos
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - Marti Santiago
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - Rocío M de Pablos
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - José L Venero
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
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17
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Tuttolomondo A, Colomba C, Di Bona D, Casuccio A, Di Raimondo D, Clemente G, Arnao V, Pecoraro R, Ragonese P, Aiello A, Accardi G, Maugeri R, Maida C, Simonetta I, Della Corte V, Iacopino DG, Caruso C, Cascio A, Pinto A. HLA and killer cell immunoglobulin-like receptor (KIRs) genotyping in patients with acute viral encephalitis. Oncotarget 2018; 9:17523-17532. [PMID: 29707126 PMCID: PMC5915134 DOI: 10.18632/oncotarget.24778] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/25/2018] [Indexed: 12/21/2022] Open
Abstract
Introduction The HLA genes, as well as the innate immune KIR genes, are considered relevant determinants of viral outcomes but no study, to our knowledge, has evaluated their role in the clinical setting of acute viral encephalitis. Results Subjects with acute viral encephalitis in comparison to subjects without acute viral encephalitis showed a significantly higher frequency of 2DL1 KIR gene and AA KIR haplotypes and of HLA-C2 and HLA-A-Bw4 alleles. Subjects without acute viral encephalitis showed a higher frequency of interaction between KIR2DL2 and HLAC1. Multiple logistic regression analysis showed the detrimental effect of HLA-A haplotype and HLA-C1, HLA-A-BW4 HLA-B-BW4T alleles, whereas multiple logistic regression showed a protective effect of AB+BB KIR haplotype and a detrimental effect of interaction between KIR3DL1 and HLA-A-Bw4. Discussion Our findings of a lower frequency of activating receptors in patients with acute encephalitis compared to controls could result in a less efficient response of NK cells. This finding could represent a possible pathogenetic explanation of susceptibility to acute symptomatic encephalitis in patients with viral infection from potentially responsible viruses such as Herpes virus. Materials and Methods 30 Consecutive patients with symptomatic acute viral encephalitis and as controls, 36 consecutive subjects without acute encephalitis were analyzed. The following KIR genes were analyzed, KIR2DL1, 2DL2, 2DL3, 2DL5, 3DL1, 3DL2, 3DL3, 2DL4, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DS1, 2 pseudogenes (2DP1 and 3DP1) and the common variants of KIR2DL5 (KIR2DL5A, KIR2DL5B).
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Affiliation(s)
- Antonino Tuttolomondo
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), Università degli Studi di Palermo, Palermo, Italy
| | - Claudia Colomba
- U.O.C di Malattie Infettive, Dipartimento di Scienze per la Promozione della Salute e Materno Infantile G. D'Alessandro, Università degli Studi di Palermo, Palermo, Italy
| | - Danilo Di Bona
- School of Allergology, Dipartimento delle Emergenze e Trapianti d'Organo, University of Bari, Bari, Italy
| | - Alessandra Casuccio
- Dipartimento di Scienze per la Promozione della Salute e Materno Infantile "G. D'Alessandro", Università degli Studi di Palermo, Palermo, Italy
| | - Domenico Di Raimondo
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), Università degli Studi di Palermo, Palermo, Italy
| | - Giuseppe Clemente
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), Università degli Studi di Palermo, Palermo, Italy
| | - Valentina Arnao
- Dipartimento di BioMedicina Sperimentale e Neuroscienze Cliniche, Università degli Studi di Palermo, Palermo, Italy
| | - Rosaria Pecoraro
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), Università degli Studi di Palermo, Palermo, Italy
| | - Paolo Ragonese
- Dipartimento di BioMedicina Sperimentale e Neuroscienze Cliniche, Università degli Studi di Palermo, Palermo, Italy
| | - Anna Aiello
- Dipartimento di Biopatologia e Biotecnologie Mediche, Università degli Studi di Palermo, Palermo, Italy
| | - Giulia Accardi
- Dipartimento di Biopatologia e Biotecnologie Mediche, Università degli Studi di Palermo, Palermo, Italy
| | - Rosario Maugeri
- Dipartimento di BioMedicina Sperimentale e Neuroscienze Cliniche, Università degli Studi di Palermo, Palermo, Italy
| | - Carlo Maida
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), Università degli Studi di Palermo, Palermo, Italy
| | - Irene Simonetta
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), Università degli Studi di Palermo, Palermo, Italy
| | - Vittoriano Della Corte
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), Università degli Studi di Palermo, Palermo, Italy
| | - Domenico Gerardo Iacopino
- Dipartimento di BioMedicina Sperimentale e Neuroscienze Cliniche, Università degli Studi di Palermo, Palermo, Italy
| | - Calogero Caruso
- Dipartimento di Biopatologia e Biotecnologie Mediche, Università degli Studi di Palermo, Palermo, Italy
| | - Antonio Cascio
- U.O.C di Malattie Infettive, Dipartimento di Scienze per la Promozione della Salute e Materno Infantile G. D'Alessandro, Università degli Studi di Palermo, Palermo, Italy
| | - Antonio Pinto
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), Università degli Studi di Palermo, Palermo, Italy
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18
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Li Y, Zhang H, Zhu B, Ashraf U, Chen Z, Xu Q, Zhou D, Zheng B, Song Y, Chen H, Ye J, Cao S. Microarray Analysis Identifies the Potential Role of Long Non-Coding RNA in Regulating Neuroinflammation during Japanese Encephalitis Virus Infection. Front Immunol 2017; 8:1237. [PMID: 29033949 PMCID: PMC5626832 DOI: 10.3389/fimmu.2017.01237] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 09/19/2017] [Indexed: 01/31/2023] Open
Abstract
Japanese encephalitis virus (JEV) is the leading cause of epidemic encephalitis worldwide. JEV-induced neuroinflammation is characterized by profound neuronal cells damage accompanied by activation of glial cells. Albeit long non-coding RNAs (lncRNAs) have been emerged as important regulatory RNAs with profound effects on various biological processes, it is unknown how lncRNAs regulate JEV-induced inflammation. Here, using microarray approach, we identified 618 lncRNAs and 1,007 mRNAs differentially expressed in JEV-infected mice brain. The functional annotation analysis revealed that differentially regulated transcripts were predominantly involved in various signaling pathways related to host immune and inflammatory responses. The lncRNAs with their potential to regulate JEV-induced inflammatory response were identified by constructing the lncRNA-mRNA coexpression network. Furthermore, silencing of the two selected lncRNAs (E52329 and N54010) resulted in reducing the phosphorylation of JNK and MKK4, which are known to be involved during inflammatory response. Collectively, we first demonstrated the transcriptomic landscape of lncRNAs in mice brain infected with JEV and analyzed the coexpression network of differentially regulated lncRNAs and mRNAs during JEV infection. Our results provide a better understanding of the host response to JEV infection and suggest that the identified lncRNAs may be used as potential therapeutic targets for the management of Japanese encephalitis.
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Affiliation(s)
- Yunchuan Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Hao Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Bibo Zhu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Usama Ashraf
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Zheng Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Qiuping Xu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Dengyuan Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Bohan Zheng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Yunfeng Song
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Jing Ye
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Shengbo Cao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
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19
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Lindenau JD, Altmann V, Schumacher-Schuh AF, Rieder CR, Hutz MH. Tumor necrosis factor alpha polymorphisms are associated with Parkinson's disease age at onset. Neurosci Lett 2017; 658:133-136. [PMID: 28844731 DOI: 10.1016/j.neulet.2017.08.049] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 08/16/2017] [Accepted: 08/20/2017] [Indexed: 12/31/2022]
Abstract
The role of neuroinflammation in Parkinson's disease (PD) has been demonstrated through several different approaches. It was suggested an inflammation-derived oxidative stress and cytokine-dependent toxicity role in the nigrostriatal pathway degeneration and hasten progression of disease. Tumor necrosis factor alpha (TNFA) gene promoter polymorphisms might alter the expression of this cytokine contributing to the pro- and anti-inflammatory polarization. An increased TNFA expression might lead to inflammatory profile predominance. The aim of study was to determine if TNFA haplotypes are associated with PD age at onset. Five polymorphisms in TNFA gene were investigated in 226 patients with idiopathic PD in relation to age at onset. Haplotype grouping was based on allele expression. Logistic binary regression analysis showed that the genetic background leading to higher TNF-α expression confers a higher risk to develop PD earlier. Gender and ancestry did not differ between groups. High TNFA expression may contribute for faster dopaminergic neuron degeneration. In this context, a higher genetic pro-inflammatory profile confers a higher risk to develop PD earlier.
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Affiliation(s)
- Juliana D Lindenau
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Brazil
| | - Vivian Altmann
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Brazil
| | | | - Carlos R Rieder
- Serviço de Neurologia, Hospital de Clínicas de Porto Alegre, Brazil
| | - Mara H Hutz
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Brazil.
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20
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Joers V, Tansey MG, Mulas G, Carta AR. Microglial phenotypes in Parkinson's disease and animal models of the disease. Prog Neurobiol 2017; 155:57-75. [PMID: 27107797 PMCID: PMC5073045 DOI: 10.1016/j.pneurobio.2016.04.006] [Citation(s) in RCA: 185] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 12/19/2022]
Abstract
Over the last decade the important concept has emerged that microglia, similar to other tissue macrophages, assume different phenotypes and serve several effector functions, generating the theory that activated microglia can be organized by their pro-inflammatory or anti-inflammatory and repairing functions. Importantly, microglia exist in a heterogenous population and their phenotypes are not permanently polarized into two categories; they exist along a continuum where they acquire different profiles based on their local environment. In Parkinson's disease (PD), neuroinflammation and microglia activation are considered neuropathological hallmarks, however their precise role in relation to disease progression is not clear, yet represent a critical challenge in the search of disease-modifying strategies. This review will critically address current knowledge on the activation states of microglia as well as microglial phenotypes found in PD and in animal models of PD, focusing on the expression of surface molecules as well as pro-inflammatory and anti-inflammatory cytokine production during the disease process. While human studies have reported an elevation of both pro- or anti-inflammatory markers in the serum and CSF of PD patients, animal models have provided insights on dynamic changes of microglia phenotypes in relation to disease progression especially prior to the development of motor deficits. We also review recent evidence of malfunction at multiple steps of NFκB signaling that may have a causal interrelationship with pathological microglia activation in animal models of PD. Finally, we discuss the immune-modifying strategies that have been explored regarding mechanisms of chronic microglial activation.
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Affiliation(s)
- Valerie Joers
- Department of Physiology, Emory University, Atlanta, GA, United States; Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Malú G Tansey
- Department of Physiology, Emory University, Atlanta, GA, United States.
| | - Giovanna Mulas
- Department of Biomedical Sciences, University of Cagliari, Italy
| | - Anna R Carta
- Department of Biomedical Sciences, University of Cagliari, Italy.
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21
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Labandeira-Garcia JL, Rodríguez-Perez AI, Garrido-Gil P, Rodriguez-Pallares J, Lanciego JL, Guerra MJ. Brain Renin-Angiotensin System and Microglial Polarization: Implications for Aging and Neurodegeneration. Front Aging Neurosci 2017; 9:129. [PMID: 28515690 PMCID: PMC5413566 DOI: 10.3389/fnagi.2017.00129] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/18/2017] [Indexed: 12/12/2022] Open
Abstract
Microglia can transform into proinflammatory/classically activated (M1) or anti-inflammatory/alternatively activated (M2) phenotypes following environmental signals related to physiological conditions or brain lesions. An adequate transition from the M1 (proinflammatory) to M2 (immunoregulatory) phenotype is necessary to counteract brain damage. Several factors involved in microglial polarization have already been identified. However, the effects of the brain renin-angiotensin system (RAS) on microglial polarization are less known. It is well known that there is a “classical” circulating RAS; however, a second RAS (local or tissue RAS) has been observed in many tissues, including brain. The locally formed angiotensin is involved in local pathological changes of these tissues and modulates immune cells, which are equipped with all the components of the RAS. There are also recent data showing that brain RAS plays a major role in microglial polarization. Level of microglial NADPH-oxidase (Nox) activation is a major regulator of the shift between M1/proinflammatory and M2/immunoregulatory microglial phenotypes so that Nox activation promotes the proinflammatory and inhibits the immunoregulatory phenotype. Angiotensin II (Ang II), via its type 1 receptor (AT1), is a major activator of the NADPH-oxidase complex, leading to pro-oxidative and pro-inflammatory effects. However, these effects are counteracted by a RAS opposite arm constituted by Angiotensin II/AT2 receptor signaling and Angiotensin 1–7/Mas receptor (MasR) signaling. In addition, activation of prorenin-renin receptors may contribute to activation of the proinflammatory phenotype. Aged brains showed upregulation of AT1 and downregulation of AT2 receptor expression, which may contribute to a pro-oxidative pro-inflammatory state and the increase in neuron vulnerability. Several recent studies have shown interactions between the brain RAS and different factors involved in microglial polarization, such as estrogens, Rho kinase (ROCK), insulin-like growth factor-1 (IGF-1), tumor necrosis factor α (TNF)-α, iron, peroxisome proliferator-activated receptor gamma, and toll-like receptors (TLRs). Metabolic reprogramming has recently been involved in the regulation of the neuroinflammatory response. Interestingly, we have recently observed a mitochondrial RAS, which is altered in aged brains. In conclusion, dysregulation of brain RAS plays a major role in aging-related changes and neurodegeneration by exacerbation of oxidative
stress (OS) and neuroinflammation, which may be attenuated by pharmacological manipulation of RAS components.
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Affiliation(s)
- Jose L Labandeira-Garcia
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
| | - Ana I Rodríguez-Perez
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
| | - Pablo Garrido-Gil
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
| | - Jannette Rodriguez-Pallares
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
| | - Jose L Lanciego
- Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain.,Neurosciences Division, Center for Applied Medical Research (CIMA), University of NavarraPamplona, Spain
| | - Maria J Guerra
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de CompostelaSantiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED)Madrid, Spain
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22
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Ye J, Zhang H, He W, Zhu B, Zhou D, Chen Z, Ashraf U, Wei Y, Liu Z, Fu ZF, Chen H, Cao S. Quantitative phosphoproteomic analysis identifies the critical role of JNK1 in neuroinflammation induced by Japanese encephalitis virus. Sci Signal 2016; 9:ra98. [DOI: 10.1126/scisignal.aaf5132] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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23
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microRNA-155 Regulates Alpha-Synuclein-Induced Inflammatory Responses in Models of Parkinson Disease. J Neurosci 2016; 36:2383-90. [PMID: 26911687 DOI: 10.1523/jneurosci.3900-15.2016] [Citation(s) in RCA: 180] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Increasing evidence points to inflammation as a chief mediator of Parkinson's disease (PD), a progressive neurodegenerative disorder characterized by loss of dopamine neurons in the substantia nigra pars compacta (SNpc) and widespread aggregates of the protein α-synuclein (α-syn). Recently, microRNAs, small, noncoding RNAs involved in regulating gene expression at the posttranscriptional level, have been recognized as important regulators of the inflammatory environment. Using an array approach, we found significant upregulation of microRNA-155 (miR-155) in an in vivo model of PD produced by adeno-associated-virus-mediated expression of α-syn. Using a mouse with a complete deletion of miR-155, we found that loss of miR-155 reduced proinflammatory responses to α-syn and blocked α-syn-induced neurodegeneration. In primary microglia from miR-155(-/-) mice, we observed a markedly reduced inflammatory response to α-syn fibrils, with attenuation of major histocompatibility complex class II (MHCII) and proinflammatory inducible nitric oxide synthase expression. Treatment of these microglia with a synthetic mimic of miR-155 restored the inflammatory response to α-syn fibrils. Our results suggest that miR-155 has a central role in the inflammatory response to α-syn in the brain and in α-syn-related neurodegeneration. These effects are at least in part due to a direct role of miR-155 on the microglial response to α-syn. These data implicate miR-155 as a potential therapeutic target for regulating the inflammatory response in PD.
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24
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Ponnazhagan R, Harms AS, Thome AD, Jurkuvenaite A, Gogliotti R, Niswender CM, Conn PJ, Standaert DG. The Metabotropic Glutamate Receptor 4 Positive Allosteric Modulator ADX88178 Inhibits Inflammatory Responses in Primary Microglia. J Neuroimmune Pharmacol 2016; 11:231-7. [PMID: 26872456 PMCID: PMC4848139 DOI: 10.1007/s11481-016-9655-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Accepted: 02/03/2016] [Indexed: 11/27/2022]
Abstract
While the specific trigger of Parkinson Disease (PD) in most patients is unknown, considerable evidence suggests that the neuroinflammatory response makes an essential contribution to the neurodegenerative process. Drugs targeting metabotropic glutamate receptors (mGlu receptors), 7 Transmembrane (7TM) spanning/G protein coupled receptors that bind glutamate, are emerging as therapeutic targets for PD and may have anti-inflammatory properties. ADX88178 is novel potent, selective, and brain-penetrant positive allosteric modulator of the mGlu4 which is under evaluation for treatment of PD and other neurological disorders. We used microglia cultured from mouse brain to determine if ADX88178 had direct effects on the inflammatory responses of these cells. We studied both microglia from wild type and Grm4 knock out mice. We found that activation of mGlu4 with ADX88178 attenuated LPS-induced inflammation in primary microglia, leading to a decrease in the expression of TNFα, MHCII, and iNOS, markers of pro-inflammatory responses. These effects were absent in microglia from mice lacking mGlu4. These results demonstrate a cell-autonomous anti-inflammatory effect of ADX88178 mediated mGlu4 activation on microglia, and suggest that this drug or similar activators or potentiators of mGlu4 may have disease-modifying as well as symptomatic effects in PD and other brain disorders with an inflammatory component.
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Affiliation(s)
- Ranjani Ponnazhagan
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Ashley S Harms
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Aaron D Thome
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Asta Jurkuvenaite
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Rocco Gogliotti
- Vanderbilt Center for Neuroscience Drug Discovery, Department of Pharmacology, Vanderbilt Kennedy Center, Vanderbilt University, Nashville, TN, 37235, USA
| | - Colleen M Niswender
- Vanderbilt Center for Neuroscience Drug Discovery, Department of Pharmacology, Vanderbilt Kennedy Center, Vanderbilt University, Nashville, TN, 37235, USA
| | - P Jeffrey Conn
- Vanderbilt Center for Neuroscience Drug Discovery, Department of Pharmacology, Vanderbilt Kennedy Center, Vanderbilt University, Nashville, TN, 37235, USA
| | - David G Standaert
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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25
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Zhang H, Sun J, Ye J, Ashraf U, Chen Z, Zhu B, He W, Xu Q, Wei Y, Chen H, Fu ZF, Liu R, Cao S. Quantitative Label-Free Phosphoproteomics Reveals Differentially Regulated Protein Phosphorylation Involved in West Nile Virus-Induced Host Inflammatory Response. J Proteome Res 2015; 14:5157-68. [DOI: 10.1021/acs.jproteome.5b00424] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Zhen F. Fu
- Department
of Pathology, University of Georgia, Athens, Georgia 30602, United States
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26
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Fractalkine Signaling Regulates the Inflammatory Response in an α-Synuclein Model of Parkinson Disease. PLoS One 2015; 10:e0140566. [PMID: 26469270 PMCID: PMC4607155 DOI: 10.1371/journal.pone.0140566] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 09/28/2015] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Parkinson disease (PD) is a progressive neurodegenerative disorder characterized by loss of dopamine neurons in the substantia nigra pars compacta (SNpc) and widespread aggregates of the protein alpha-synuclein (α-syn). Increasing evidence points to inflammation as a chief mediator; however, the role of α-syn in triggering and sustaining inflammation remains unclear. In models of Alzheimer's disease (AD), multiple sclerosis (MS) and neurotoxin models of PD, the chemokine CX3CL1 (fractalkine) and its receptor (CX3CR1) have important roles in modulating neuroinflammation. METHODS To examine the role of fractalkine signaling in α-syn-induced-neuroinflammation and neurodegeneration, we used an in vivo mouse model in which human α-syn is overexpressed by an adeno associated viral vector serotype 2 (AAV2) and in vitro phagocytosis and protein internalization assays with primary microglia treated with aggregated α-syn. RESULTS We observed that loss of CX3CR1 expression led to a reduced inflammatory response, with reduced IgG deposition and expression of MHCII 4 weeks post-transduction. Six months post transduction, AAV2 mediated overexpression of α-syn leads to loss of dopaminergic neurons, and this loss was not exacerbated in animals with deletion of CX3CR1. To determine the mechanism by which CX3CR1affects inflammatory responses in α-syn-induced inflammation, phagocytosis was assessed using a fluorescent microsphere assay as well as by microglial uptake of aggregated α-syn. CX3CR1-/- microglia showed reduced uptake of fluorescent beads and aggregated α-syn. CONCLUSION Our results suggest that one mechanism by which CX3CR1-/- attenuates inflammation is at the level of phagocytosis of aggregated α-syn by microglia. These data implicate fractalkine signaling as a potential therapeutic target for regulating inflammatory response in α-syn models PD.
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27
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Yao N, Wu Y, Zhou Y, Ju L, Liu Y, Ju R, Duan D, Xu Q. Lesion of the locus coeruleus aggravates dopaminergic neuron degeneration by modulating microglial function in mouse models of Parkinson׳s disease. Brain Res 2015; 1625:255-74. [PMID: 26342895 DOI: 10.1016/j.brainres.2015.08.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/11/2015] [Accepted: 08/25/2015] [Indexed: 02/06/2023]
Abstract
The degeneration of noradrenergic neurons in the locus coeruleus (LC) commonly occurs in patients with Parkinson's disease (PD), which is characterized by a selective injury of dopaminergic neurons in the substantia nigra (SN). The pathological impact of the LC on the SN in the disease is unknown. In the present study, we used a noradrenergic toxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4), to deplete noradrenaline (NA) derived from the LC to explore its influence on degeneration or injury of dopaminergic neurons in the SN in mouse model produced by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or lipopolysaccharide (LPS). Our results demonstrated that lesion of the LC could change microglial function in the brain, which led to enhanced or prolonged expression of pro-inflammatory cytokines, diminished neurotrophic factors, and weakened ability of anti-oxidation in the SN. The in vitro experiments further confirmed that NA could reduce the inflammatory reaction of microglia. The selective injury of dopaminergic neurons by inflammation, however, was due to the inflammation in different brain regions rather than the depletion of NA. Our results indicate that the lesion in the LC is an important factor in promoting dopaminergic neuron degeneration by impacting the function of microglia in the midbrain.
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Affiliation(s)
- Ning Yao
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Yanhong Wu
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China; Beijing Children׳s Hospital Affiliated to Capital Medical University, Beijing 100045, China
| | - Yan Zhou
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Lili Ju
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Yujun Liu
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Rongkai Ju
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Deyi Duan
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Qunyuan Xu
- Department of Neurobiology, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Capital Medical University, Beijing 100069, China.
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28
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Volden TA, Reyelts CD, Hoke TA, Arikkath J, Bonasera SJ. Validation of Flow Cytometry and Magnetic Bead-Based Methods to Enrich CNS Single Cell Suspensions for Quiescent Microglia. J Neuroimmune Pharmacol 2015; 10:655-65. [PMID: 26260923 DOI: 10.1007/s11481-015-9628-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 07/30/2015] [Indexed: 11/29/2022]
Abstract
Microglia are resident mononuclear phagocytes within the CNS parenchyma that intimately interact with neurons and astrocytes to remodel synapses and extracellular matrix. We briefly review studies elucidating the molecular pathways that underlie microglial surveillance, activation, chemotaxis, and phagocytosis; we additionally place these studies in a clinical context. We describe and validate an inexpensive and simple approach to obtain enriched single cell suspensions of quiescent parenchymal and perivascular microglia from the mouse cerebellum and hypothalamus. Following preparation of regional CNS single cell suspensions, we remove myelin debris, and then perform two serial enrichment steps for cells expressing surface CD11b. Myelin depletion and CD11b enrichment are both accomplished using antigen-specific magnetic beads in an automated cell separation system. Flow cytometry of the resultant suspensions shows a significant enrichment for CD11b(+)/CD45(+) cells (perivascular microglia) and CD11b(+)/CD45(-) cells (parenchymal microglia) compared to starting suspensions. Of note, cells from these enriched suspensions minimally express Aif1 (aka Iba1), suggesting that the enrichment process does not evoke significant microglial activation. However, these cells readily respond to a functional challenge (LPS) with significant changes in the expression of molecules specifically associated with microglia. We conclude that methods employing a combination of magnetic-bead based sorting and flow cytometry produce suspensions highly enriched for microglia that are appropriate for a variety of molecular and cellular assays.
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Affiliation(s)
- T A Volden
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - C D Reyelts
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - T A Hoke
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - J Arikkath
- Developmental Neuroscience, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - S J Bonasera
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA. .,University of Nebraska Medical Center, 3028 Durham Research Center II, Omaha, NE, 68198-5039, USA.
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Barnum CJ, Chen X, Chung J, Chang J, Williams M, Grigoryan N, Tesi RJ, Tansey MG. Peripheral administration of the selective inhibitor of soluble tumor necrosis factor (TNF) XPro®1595 attenuates nigral cell loss and glial activation in 6-OHDA hemiparkinsonian rats. JOURNAL OF PARKINSONS DISEASE 2015; 4:349-60. [PMID: 25061061 DOI: 10.3233/jpd-140410] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Parkinson's disease (PD) is a complex multi-system age-related neurodegenerative disorder. Targeting the ongoing neuroinflammation in PD patients is one strategy postulated to slow down or halt disease progression. Proof-of-concept studies from our group demonstrated that selective inhibition of soluble Tumor Necrosis Factor (solTNF) by intranigral delivery of dominant negative TNF (DN-TNF) inhibitors reduced neuroinflammation and nigral dopamine (DA) neuron loss in endotoxin and neurotoxin rat models of nigral degeneration. OBJECTIVE As a next step toward human clinical trials, we aimed to determine the extent to which peripherally administered DN-TNF inhibitor XPro®1595 could: i) cross the blood-brain-barrier in therapeutically relevant concentrations, ii) attenuate neuroinflammation (microglia and astrocyte), and iii) mitigate loss of nigral DA neurons in rats receiving a unilateral 6-hydroxydopamine (6-OHDA) striatal lesion. METHODS Rats received unilateral 6-OHDA (20 μg into the right striatum). Three or 14 days after lesion, rats were dosed with XPro®1595 (10 mg/kg in saline, subcutaneous) every third day for 35 days. Forelimb asymmetry was used to assess motor deficits after the lesion; brains were harvested 35 days after the lesion for analysis of XPro®1595 levels, glial activation and nigral DA neuron number. RESULTS Peripheral subcutaneous dosing of XPro®1595 achieved plasma levels of 1-8 microgram/mL and CSF levels of 1-6 ng/mL depending on the time the rats were killed after final XPro®1595 injection. Irrespective of start date, XPro®1595 significantly reduced microglia and astrocyte number in SNpc whereas loss of nigral DA neurons was attenuated when drug was started 3, but not 14 days after the 6-OHDA lesion. CONCLUSIONS Our data suggest that systemically administered XPro®1595 may have disease-modifying potential in PD patients where inflammation is part of their pathology.
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Affiliation(s)
| | - Xi Chen
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Jaegwon Chung
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Jianjun Chang
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Martha Williams
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Nelly Grigoryan
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
| | | | - Malú G Tansey
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
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Pisanu A, Lecca D, Mulas G, Wardas J, Simbula G, Spiga S, Carta AR. Dynamic changes in pro- and anti-inflammatory cytokines in microglia after PPAR-γ agonist neuroprotective treatment in the MPTPp mouse model of progressive Parkinson's disease. Neurobiol Dis 2014; 71:280-91. [DOI: 10.1016/j.nbd.2014.08.011] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 07/31/2014] [Accepted: 08/06/2014] [Indexed: 11/25/2022] Open
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Lee EJ, Han JE, Woo MS, Shin JA, Park EM, Kang JL, Moon PG, Baek MC, Son WS, Ko YT, Choi JW, Kim HS. Matrix metalloproteinase-8 plays a pivotal role in neuroinflammation by modulating TNF-α activation. THE JOURNAL OF IMMUNOLOGY 2014; 193:2384-93. [PMID: 25049354 DOI: 10.4049/jimmunol.1303240] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Matrix metalloproteinases (MMPs) play important roles in normal brain development and synaptic plasticity, although aberrant expression of MMPs leads to brain damage, including blood-brain barrier disruption, inflammation, demyelination, and neuronal cell death. In this article, we report that MMP-8 is upregulated in LPS-stimulated BV2 microglial cells and primary cultured microglia, and treatment of MMP-8 inhibitor (M8I) or MMP-8 short hairpin RNA suppresses proinflammatory molecules, particularly TNF-α secretion. Subsequent experiments showed that MMP-8 exhibits TNF-α-converting enzyme (TACE) activity by cleaving the prodomain of TNF-α (A(74)/Q(75), A(76)/V(77) residues) and, furthermore, that M8I inhibits TACE activity more efficiently than TAPI-0, a general TACE inhibitor. Biochemical analysis of the underlying anti-inflammatory mechanisms of M8I revealed that it inhibits MAPK phosphorylation, NF-κB/AP-1 activity, and reactive oxygen species production. Further support for the proinflammatory role of microglial MMP-8 was obtained from an in vivo animal model of neuroinflammatory disorder. MMP-8 is upregulated in septic conditions, particularly in microglia. Administration of M8I or MMP-8 short hairpin RNA significantly inhibits microglial activation and expression/secretion of TNF-α in brain tissue, serum, and cerebrospinal fluid of LPS-induced septic mice. These results demonstrate that MMP-8 critically mediates microglial activation by modulating TNF-α activity, which may explain neuroinflammation in septic mouse brain.
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Affiliation(s)
- Eun-Jung Lee
- Department of Molecular Medicine and Global Top 5 Research Program, Tissue Injury Defense Research Center, Ewha Womans University Medical School, Seoul 158-710, Republic of Korea
| | - Jeong Eun Han
- College of Pharmacy, Gachon University, Incheon 406-799, Republic of Korea
| | - Moon-Sook Woo
- Department of Molecular Medicine and Global Top 5 Research Program, Tissue Injury Defense Research Center, Ewha Womans University Medical School, Seoul 158-710, Republic of Korea
| | - Jin A Shin
- Department of Pharmacology, Ewha Womans University Medical School, Seoul 158-710, Republic of Korea
| | - Eun-Mi Park
- Department of Pharmacology, Ewha Womans University Medical School, Seoul 158-710, Republic of Korea
| | - Jihee Lee Kang
- Department of Physiology, Ewha Womans University Medical School, Seoul 158-710, Republic of Korea
| | - Pyong Gon Moon
- Department of Molecular Medicine, Kyongbuk National University, Daegu 700-842, Republic of Korea; and
| | - Moon-Chang Baek
- Department of Molecular Medicine, Kyongbuk National University, Daegu 700-842, Republic of Korea; and
| | - Woo-Sung Son
- College of Pharmacy, CHA University, Pocheon-si 487-010, Republic of Korea
| | - Young Tag Ko
- College of Pharmacy, Gachon University, Incheon 406-799, Republic of Korea
| | - Ji Woong Choi
- College of Pharmacy, Gachon University, Incheon 406-799, Republic of Korea;
| | - Hee-Sun Kim
- Department of Molecular Medicine and Global Top 5 Research Program, Tissue Injury Defense Research Center, Ewha Womans University Medical School, Seoul 158-710, Republic of Korea;
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Borrajo A, Rodriguez-Perez AI, Diaz-Ruiz C, Guerra MJ, Labandeira-Garcia JL. Microglial TNF-α mediates enhancement of dopaminergic degeneration by brain angiotensin. Glia 2014; 62:145-57. [PMID: 24272709 DOI: 10.1002/glia.22595] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/14/2013] [Accepted: 10/16/2013] [Indexed: 11/11/2022]
Abstract
In vitro and in vivo models of Parkinson's disease were used to investigate whether TNF-α plays a major role in the enhancement of the microglial response and dopaminergic degeneration induced by brain angiotensin hyperactivity. Treatment of primary mesencephalic cultures with low doses of the neurotoxin MPP(+) induced a significant loss of dopaminergic neurons, which was enhanced by cotreatment with angiotensin II and inhibited by TNF-α inhibitors. Treatment of primary cultures with angiotensin induced a marked increase in levels of TNF-α, which was inhibited by treatment with angiotensin type-1-receptor antagonists, NADPH-oxidase inhibitors and NFK-β inhibitors. However, TNF-α levels were not significantly affected by treatment with angiotensin in the absence of microglia. The microglial origin of the angiotensin-induced increase in TNF-α levels was confirmed using dopaminergic (MES 23.5) and microglial (N9) cell lines. Inhibition of the microglial Rho-kinase activity also blocked the AII-induced increase in TNF-α levels. Treatment of the dopaminergic cell line with TNF-α revealed that NFK-β activation mediates the deleterious effect of microglial TNF-α on dopaminergic neurons. Treatment of mice with MPTP also induced significant increases in striatal and nigral TNF-α levels, which were inhibited by angiotensin type-1-receptor antagonists or NFK-β inhibitors. The present results show that microglial TNF-α plays a major role in angiotensin-induced dopaminergic cell death and that the microglial release of TNF-α is mediated by activation of angiotensin type-1 receptors, NADPH-oxidase, Rho-kinase and NFK-β.
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Affiliation(s)
- Ana Borrajo
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Faculty of Medicine, University of Santiago de Compostela, Santiago de Compostela, Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain
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In vitro cytokines profile and ultrastructural changes of microglia and macrophages following interaction with Leishmania. Parasitology 2014; 141:1052-63. [PMID: 24717447 DOI: 10.1017/s0031182014000274] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In the present study, we assessed morphological changes and cytokine production after in vitro interaction with causative agents of American cutaneous leishmaniasis and compared the microglia and macrophage immune responses. Cultures of microglia and macrophages infected with stationary-phase promastigotes of Leishmania (Viannia) shawi, Leishmania (Viannia) braziliensis or Leishmania (Leishmania) amazonensis were evaluated 24, 48 and 72 h after interaction. Macrophages only presented the classical phagocytic process while microglia also displayed large cytoplasmic projections similar to the ruffles described in macropinocytosis. In the macrophage cultures, the percentage of infected cells increased over time, in a fashion that was dependent on the parasite species. In contrast, in microglial cells as the culture time progressed, there was a significant reduction in the percentage of infected cells independent of parasite species. Measurements of cytokines in macrophage cultures 48 h after interactions revealed distinct expression patterns for different parasites, whereas in microglial cultures they were similar for all Leishmania tested species. Taken together, our results suggest that microglia may have a higher phagocytic ability and cytotoxic potential than macrophages for all investigated species. The robust response of microglia against all parasite species may suggest microglia have an important role in the defence against cerebral leishmaniasis.
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Moshkin MP, Akulov AE, Petrovski DV, Saik OV, Petrovskiy ED, Savelov AA, Koptyug IV. Proton magnetic resonance spectroscopy of brain metabolic shifts induced by acute administration of 2-deoxy-d-glucose and lipopolysaccharides. NMR IN BIOMEDICINE 2014; 27:399-405. [PMID: 24493094 DOI: 10.1002/nbm.3074] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 12/05/2013] [Accepted: 12/11/2013] [Indexed: 06/03/2023]
Abstract
In vivo proton magnetic resonance spectroscopy ((1) H MRS) of outbred stock ICR male mice (originating from the Institute of Cancer Research) was used to study the brain (hippocampus) metabolic response to the pro-inflammatory stimulus and to the acute deficiency of the available energy, which was confirmed by measuring the maximum oxygen consumption. Inhibition of glycolysis by means of an injection with 2-deoxy-d-glucose (2DG) reduced the levels of gamma-aminobutyric acid (GABA, p < 0.05, in comparison with control, least significant difference (LSD) test), N-acetylaspartate (NAA, p < 0.05, LSD test) and choline compounds, and at the same time increased the levels of glutamate and glutamine. An opposite effect was found after injection with bacterial lipopolysaccharide (LPS) - a very common pro-inflammatory inducer. An increase in the amounts of GABA, NAA and choline compounds in the brain occurred in mice treated with LPS. Different metabolic responses to the energy deficiency and the pro-inflammatory stimuli can explain the contradictory results of the brain (1) H MRS studies under neurodegenerative pathology, which is accompanied by both mitochondrial dysfunction and inflammation. The prevalence of the excitatory metabolites such as glutamate and glutamine in 2DG treated mice is in good agreement with excitation observed during temporary reduction of the available energy under acute hypoxia or starvation. In turn, LPS, as an inducer of the sickness behavior, which was manifested as depression, sleepiness, loss of appetite etc., shifts the brain metabolic pattern toward the prevalence of the inhibitory neurotransmitter GABA.
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Affiliation(s)
- Mikhail P Moshkin
- Institute of Cytology and Genetics, Siberian Branch of RAS, Novosibirsk, Russia
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Ye J, Jiang R, Cui M, Zhu B, Sun L, Wang Y, Zohaib A, Dong Q, Ruan X, Song Y, He W, Chen H, Cao S. Etanercept reduces neuroinflammation and lethality in mouse model of Japanese encephalitis. J Infect Dis 2014; 210:875-89. [PMID: 24652493 DOI: 10.1093/infdis/jiu179] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Japanese encephalitis virus (JEV) is a neurotropic flavivirus that causes Japanese encephalitis (JE), which leads to high fatality rates in human. Tumor necrosis factor alpha (TNF-α) is a key factor that mediates immunopathology in the central nervous system (CNS) during JE. Etanercept is a safe anti-TNF-α drug that has been commonly used in the treatment of various human autoimmune diseases. METHODS The effect of etanercept on JE was investigated with a JEV-infected mouse model. Four groups of mice were assigned to receive injections of phosphate-buffered saline, etanercept, JEV, or JEV plus etanercept. Inflammatory responses in mouse brains and mortality of mice were evaluated within 23 days post infection. RESULTS The in vitro assay with mouse neuron/glia cultures showed that etanercept treatment reduced the inflammatory response induced by JEV infection. In vivo experiments further demonstrated that administration of etanercept protected mice from JEV-induced lethality. Neuronal damage, glial activation, and secretion of proinflammatory cytokines were found to be markedly decreased in JEV-infected mice that received etanercept treatment. Additionally, etanercept treatment restored the integrity of the blood-brain barrier and reduced viral load in mouse brains. CONCLUSIONS Etanercept effectively reduces the inflammation and provides protection against acute encephalitis in a JEV-infected mouse model.
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Affiliation(s)
- Jing Ye
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Rong Jiang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Min Cui
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Bibo Zhu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Leqiang Sun
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Yueyun Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Ali Zohaib
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Qian Dong
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Xindi Ruan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Yunfeng Song
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Wen He
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
| | - Shengbo Cao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R China
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Progranulin does not bind tumor necrosis factor (TNF) receptors and is not a direct regulator of TNF-dependent signaling or bioactivity in immune or neuronal cells. J Neurosci 2013; 33:9202-13. [PMID: 23699531 DOI: 10.1523/jneurosci.5336-12.2013] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Progranulin (PGRN) is a secreted glycoprotein expressed in neurons and glia that is implicated in neuronal survival on the basis that mutations in the GRN gene causing haploinsufficiency result in a familial form of frontotemporal dementia (FTD). Recently, a direct interaction between PGRN and tumor necrosis factor receptors (TNFR I/II) was reported and proposed to be a mechanism by which PGRN exerts anti-inflammatory activity, raising the possibility that aberrant PGRN-TNFR interactions underlie the molecular basis for neuroinflammation in frontotemporal lobar degeneration pathogenesis. Here, we report that we find no evidence for a direct physical or functional interaction between PGRN and TNFRs. Using coimmunoprecipitation and surface plasmon resonance (SPR) we replicated the interaction between PGRN and sortilin and that between TNF and TNFRI/II, but not the interaction between PGRN and TNFRs. Recombinant PGRN or transfection of a cDNA encoding PGRN did not antagonize TNF-dependent NFκB, Akt, and Erk1/2 pathway activation; inflammatory gene expression; or secretion of inflammatory factors in BV2 microglia and bone marrow-derived macrophages (BMDMs). Moreover, PGRN did not antagonize TNF-induced cytotoxicity on dopaminergic neuroblastoma cells. Last, co-addition or pre-incubation with various N- or C-terminal-tagged recombinant PGRNs did not alter lipopolysaccharide-induced inflammatory gene expression or cytokine secretion in any cell type examined, including BMDMs from Grn+/- or Grn-/- mice. Therefore, the neuroinflammatory phenotype associated with PGRN deficiency in the CNS is not a direct consequence of the loss of TNF antagonism by PGRN, but may be a secondary response by glia to disrupted interactions between PGRN and Sortilin and/or other binding partners yet to be identified.
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MHCII is required for α-synuclein-induced activation of microglia, CD4 T cell proliferation, and dopaminergic neurodegeneration. J Neurosci 2013; 33:9592-600. [PMID: 23739956 DOI: 10.1523/jneurosci.5610-12.2013] [Citation(s) in RCA: 286] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Accumulation of α-synuclein (α-syn) in the brain is a core feature of Parkinson disease (PD) and leads to microglial activation, production of inflammatory cytokines and chemokines, T-cell infiltration, and neurodegeneration. Here, we have used both an in vivo mouse model induced by viral overexpression of α-syn as well as in vitro systems to study the role of the MHCII complex in α-syn-induced neuroinflammation and neurodegeneration. We find that in vivo, expression of full-length human α-syn causes striking induction of MHCII expression by microglia, while knock-out of MHCII prevents α-syn-induced microglial activation, antigen presentation, IgG deposition, and the degeneration of dopaminergic neurons. In vitro, treatment of microglia with aggregated α-syn leads to activation of antigen processing and presentation of antigen sufficient to drive CD4 T-cell proliferation and to trigger cytokine release. These results indicate a central role for microglial MHCII in the activation of both the innate and adaptive immune responses to α-syn in PD and suggest that the MHCII signaling complex may be a target of neuroprotective therapies for the disease.
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Shastri A, Bonifati DM, Kishore U. Innate immunity and neuroinflammation. Mediators Inflamm 2013; 2013:342931. [PMID: 23843682 PMCID: PMC3697414 DOI: 10.1155/2013/342931] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/15/2013] [Indexed: 01/07/2023] Open
Abstract
Inflammation of central nervous system (CNS) is usually associated with trauma and infection. Neuroinflammation occurs in close relation to trauma, infection, and neurodegenerative diseases. Low-level neuroinflammation is considered to have beneficial effects whereas chronic neuroinflammation can be harmful. Innate immune system consisting of pattern-recognition receptors, macrophages, and complement system plays a key role in CNS homeostasis following injury and infection. Here, we discuss how innate immune components can also contribute to neuroinflammation and neurodegeneration.
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Affiliation(s)
- Abhishek Shastri
- Centre for Infection, Immunity and Disease Mechanisms, Heinz Wolff Building, Brunel University, London UB8 3PH, UK
| | - Domenico Marco Bonifati
- Unit of Neurology, Department of Neurological Disorders, Santa Chiara Hospital, Largo Medaglie d'oro 1, 38100 Trento, Italy
| | - Uday Kishore
- Centre for Infection, Immunity and Disease Mechanisms, Heinz Wolff Building, Brunel University, London UB8 3PH, UK
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Harms AS, Tansey MG. Isolation of murine postnatal brain microglia for phenotypic characterization using magnetic cell separation technology. Methods Mol Biol 2013; 1041:33-39. [PMID: 23813367 PMCID: PMC4141886 DOI: 10.1007/978-1-62703-520-0_5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
To shorten the time between brain harvesting and microglia isolation, and characterization, we utilized the MACS(®) neural dissociation kit followed by OctoMACS(®) CD11b magnetic bead isolation technique to positively select for brain microglia expressing the pan-microglial marker CD11b, a key subunit of the membrane attack complex (MAC). This protocol yields a viable and highly pure (>95%) microglial population of approximately 500,000 cells per pup that is amenable for in vitro characterization within hours or days after being harvested from brain tissue. Primary microglia from C57Bl/6 mice were plated for next-day analyses of morphology and cellular markers by immunocytochemistry or for analysis of gene expression under resting or LPS-stimulated conditions. The ease of isolation enables investigators to perform molecular and cellular analyses without having to wait 1-2 weeks to isolate microglia by conventional methods involving mechanical agitation to dislodge these from astrocyte beds.
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Barnum CJ, Tansey MG. Neuroinflammation and non-motor symptoms: the dark passenger of Parkinson's disease? Curr Neurol Neurosci Rep 2012; 12:350-8. [PMID: 22580742 DOI: 10.1007/s11910-012-0283-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Generally speaking, inflammation as a key piece to the Parkinson's disease (PD) puzzle is a relatively new concept. Acceptance of this concept has gained ground as studies by various researchers have demonstrated the potential of mitigating nigral cell death by curtailing inflammation in animal models of PD. We propose that the significance of inflammation in PD pathology may extend beyond the nigrostriatal region. In the current review, we present an argument for this based on the Braak staging and discuss how inflammation might contribute to the development of non-motor PD symptoms.
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Affiliation(s)
- Christopher J Barnum
- Department of Physiology, School of Medicine at Emory University, 615 Michael Street, Atlanta, GA 30324, USA
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Coelho-Santos V, Gonçalves J, Fontes-Ribeiro C, Silva AP. Prevention of methamphetamine-induced microglial cell death by TNF-α and IL-6 through activation of the JAK-STAT pathway. J Neuroinflammation 2012; 9:103. [PMID: 22642790 PMCID: PMC3391183 DOI: 10.1186/1742-2094-9-103] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 05/29/2012] [Indexed: 12/20/2022] Open
Abstract
Background It is well known that methamphetamine (METH) is neurotoxic and recent studies have suggested the involvement of neuroinflammatory processes in brain dysfunction induced by misuse of this drug. Indeed, glial cells seem to be activated in response to METH, but its effects on microglial cells are not fully understood. Moreover, it has been shown that cytokines, which are normally released by activated microglia, may have a dual role in response to brain injury. This led us to study the toxic effect of METH on microglial cells by looking to cell death and alterations of tumor necrosis factor-alpha (TNF-α) and interleukine-6 (IL-6) systems, as well as the role played by these cytokines. Methods We used the N9 microglial cell line, and cell death and proliferation were evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling assay and incorporation of bromodeoxyuridine, respectively. The TNF-α and IL-6 content was quantified by enzyme-linked immunosorbent assay, and changes in TNF receptor 1, IL-6 receptor-alpha, Bax and Bcl-2 protein levels by western blotting. Immunocytochemistry analysis was also performed to evaluate alterations in microglial morphology and in the protein expression of phospho-signal transducer and activator of transcription 3 (pSTAT3). Results METH induced microglial cell death in a concentration-dependent manner (EC50 = 1 mM), and also led to significant morphological changes and decreased cell proliferation. Additionally, this drug increased TNF-α extracellular and intracellular levels, as well as its receptor protein levels at 1 h, whereas IL-6 and its receptor levels were increased at 24 h post-exposure. However, the endogenous proinflammatory cytokines did not contribute to METH-induced microglial cell death. On the other hand, exogenous low concentrations of TNF-α or IL-6 had a protective effect. Interestingly, we also verified that the anti-apoptotic role of TNF-α was mediated by activation of IL-6 signaling, specifically the janus kinase (JAK)-STAT3 pathway, which in turn induced down-regulation of the Bax/Bcl-2 ratio. Conclusions These findings show that TNF-α and IL-6 have a protective role against METH-induced microglial cell death via the IL-6 receptor, specifically through activation of the JAK-STAT3 pathway, with consequent changes in pro- and anti-apoptotic proteins.
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Affiliation(s)
- Vanessa Coelho-Santos
- Laboratory of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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Etanercept, a widely used inhibitor of tumor necrosis factor-α (TNF-α), prevents retinal ganglion cell loss in a rat model of glaucoma. PLoS One 2012; 7:e40065. [PMID: 22802951 PMCID: PMC3388998 DOI: 10.1371/journal.pone.0040065] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 05/31/2012] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Visual loss in glaucoma is associated with pathological changes in retinal ganglion cell (RGC) axons and a slow decline in the RGC population. Age and elevated intraocular pressure (IOP) are the main risk factors for glaucomatous loss of vision. Several studies have implicated the proinflammatory cytokine tumor necrosis factor-α (TNF-α) as a link between elevated IOP and RGC death, but the cellular source of TNF-α and its causative role in RGC death remain uncertain. Here, using a rat model of glaucoma, we investigated the source of elevated TNF-α and examined whether Etanercept, a TNF-α blocker that is in common clinical use for other indications, is protective against RGC death. METHODOLOGY/PRINCIPAL FINDINGS Episcleral vein cauterization (EVC) caused intraocular pressure (IOP) to be elevated for at least 28 days. IOP elevation resulted in a dramatic increase in TNF-α levels within a few days, axonal degeneration, and a 38% loss of RGCs by 4 weeks. Immunostaining coupled with confocal microscopy showed that OHT induced robust induction of TNF-α in Iba-1-positive microglia around the optic nerve head (ONH). Despite persistent elevation of IOP, Etanercept reduced microglial activation, TNF-α levels, axon degeneration in the optic nerve, and the loss of RGCs. CONCLUSIONS/SIGNIFICANCE Ocular hypertension (OHT) triggers an inflammatory response characterized by the appearance of activated microglia around the ONH that express TNF-α. Blocking TNF-α activity with a clinically approved agent inhibits this microglial response and prevents axonal degeneration and loss of RGCs. These findings suggest a new treatment strategy for glaucoma using TNF-α antagonists or suppressors of inflammation.
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Lee JK, Chung J, Druey KM, Tansey MG. RGS10 exerts a neuroprotective role through the PKA/c-AMP response-element (CREB) pathway in dopaminergic neuron-like cells. J Neurochem 2012; 122:333-43. [PMID: 22564151 DOI: 10.1111/j.1471-4159.2012.07780.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Regulator of G-protein signaling-10 (RGS10) is a GTPase activating protein for Gαi/q/z subunits that is highly expressed in the immune system and in a broad range of brain regions including the hippocampus, striatum, dorsal raphe, and ventral midbrain. Previously, we reported that RGS10-null mice display increased vulnerability to chronic systemic inflammation-induced degeneration of nigral dopaminergic (DA) neurons. Given that RGS10 is expressed in DA neurons, we investigated the extent to which RGS10 regulates cell survival under conditions of inflammatory stress. Because of the inherent limitations associated with use of primary DA neurons for biochemical analyses, we employed a well-characterized ventral mesencephalon DA neuroblastoma cell line (MN9D) for our studies. We found that stable over-expression of RGS10 rendered them resistant to TNF-induced cytotoxicity; whereas MN9D cells expressing mutant RGS10-S168A (which is resistant to phosphorylation by protein kinase A at a serine residue that promotes its nuclear translocation) showed similar sensitivity to TNF as the parental MN9D cells. Using biochemical and pharmacologic approaches, we identified protein kinase A and the downstream phospho-cAMP response element-binding signaling pathway (and ruled out ERK 1/2, JNK, and NFkB) as key mediators of the neuroprotective effect of RGS10 against inflammatory stress.
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Affiliation(s)
- Jae-Kyung Lee
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia, USA
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