1
|
Negro-Demontel L, Maleki AF, Reich DS, Kemper C. The complement system in neurodegenerative and inflammatory diseases of the central nervous system. Front Neurol 2024; 15:1396520. [PMID: 39022733 PMCID: PMC11252048 DOI: 10.3389/fneur.2024.1396520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 06/17/2024] [Indexed: 07/20/2024] Open
Abstract
Neurodegenerative and neuroinflammatory diseases, including Alzheimer's disease, Parkinson's disease, and multiple sclerosis, affect millions of people globally. As aging is a major risk factor for neurodegenerative diseases, the continuous increase in the elderly population across Western societies is also associated with a rising prevalence of these debilitating conditions. The complement system, a crucial component of the innate immune response, has gained increasing attention for its multifaceted involvement in the normal development of the central nervous system (CNS) and the brain but also as a pathogenic driver in several neuroinflammatory disease states. Although complement is generally understood as a liver-derived and blood or interstitial fluid operative system protecting against bloodborne pathogens or threats, recent research, particularly on the role of complement in the healthy and diseased CNS, has demonstrated the importance of locally produced and activated complement components. Here, we provide a succinct overview over the known beneficial and pathological roles of complement in the CNS with focus on local sources of complement, including a discussion on the potential importance of the recently discovered intracellularly active complement system for CNS biology and on infection-triggered neurodegeneration.
Collapse
Affiliation(s)
- Luciana Negro-Demontel
- National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Complement and Inflammation Research Section (CIRS), Bethesda, MD, United States
- Department of Histology and Embryology, Faculty of Medicine, UDELAR, Montevideo, Uruguay
- Neuroinflammation and Gene Therapy Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Adam F. Maleki
- National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Complement and Inflammation Research Section (CIRS), Bethesda, MD, United States
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), NIH, Bethesda, MD, United States
| | - Daniel S. Reich
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), NIH, Bethesda, MD, United States
| | - Claudia Kemper
- National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Complement and Inflammation Research Section (CIRS), Bethesda, MD, United States
| |
Collapse
|
2
|
Parker SE, Bellingham MC, Woodruff TM. Complement drives circuit modulation in the adult brain. Prog Neurobiol 2022; 214:102282. [DOI: 10.1016/j.pneurobio.2022.102282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/24/2022] [Accepted: 05/02/2022] [Indexed: 11/16/2022]
|
3
|
Chen M, Edwards SR, Reutens DC. Complement in the Development of Post-Traumatic Epilepsy: Prospects for Drug Repurposing. J Neurotrauma 2021; 37:692-705. [PMID: 32000582 DOI: 10.1089/neu.2019.6942] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Targeting neuroinflammation is a novel frontier in the prevention and treatment of epilepsy. A substantial body of evidence supports a key role for neuroinflammation in epileptogenesis, the pathological process that leads to the development and progression of spontaneous recurrent epileptic seizures. It is also well recognized that traumatic brain injury (TBI) induces a vigorous neuroinflammatory response and that a significant proportion of patients with TBI suffer from debilitating post-traumatic epilepsy. The complement system is a potent effector of innate immunity and a significant contributor to secondary tissue damage and to epileptogenesis following central nervous system injury. Several therapeutic agents targeting the complement system are already on the market to treat other central nervous system disorders or are well advanced in their development. The purpose of this review is to summarize findings on complement activation in experimental TBI and epilepsy models, highlighting the potential of drug repurposing in the development of therapeutics to ameliorate post-traumatic epileptogenesis.
Collapse
Affiliation(s)
- Min Chen
- Center for Advanced Imaging, University of Queensland, St. Lucia, Queensland, Australia
| | - Stephen R Edwards
- Center for Advanced Imaging, University of Queensland, St. Lucia, Queensland, Australia
| | - David C Reutens
- Center for Advanced Imaging, University of Queensland, St. Lucia, Queensland, Australia
| |
Collapse
|
4
|
Kunz N, Kemper C. Complement Has Brains-Do Intracellular Complement and Immunometabolism Cooperate in Tissue Homeostasis and Behavior? Front Immunol 2021; 12:629986. [PMID: 33717157 PMCID: PMC7946832 DOI: 10.3389/fimmu.2021.629986] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/13/2021] [Indexed: 12/20/2022] Open
Abstract
The classical liver-derived and serum-effective complement system is well appreciated as a key mediator of host protection via instruction of innate and adaptive immunity. However, recent studies have discovered an intracellularly active complement system, the complosome, which has emerged as a central regulator of the core metabolic pathways fueling human immune cell activity. Induction of expression of components of the complosome, particularly complement component C3, during transmigration from the circulation into peripheral tissues is a defining characteristic of monocytes and T cells in tissues. Intracellular complement activity is required to induce metabolic reprogramming of immune cells, including increased glycolytic flux and OXPHOS, which drive the production of the pro-inflammatory cytokine IFN-γ. Consequently, reduced complosome activity translates into defects in normal monocyte activation, faulty Th1 and cytotoxic T lymphocyte responses and loss of protective tissue immunity. Intriguingly, neurological research has identified an unexpected connection between the physiological presence of innate and adaptive immune cells and certain cytokines, including IFN-γ, in and around the brain and normal brain function. In this opinion piece, we will first review the current state of research regarding complement driven metabolic reprogramming in the context of immune cell tissue entry and residency. We will then discuss how published work on the role of IFN-γ and T cells in the brain support a hypothesis that an evolutionarily conserved cooperation between the complosome, cell metabolism and IFN-γ regulates organismal behavior, as well as immunity.
Collapse
Affiliation(s)
- Natalia Kunz
- Complement and Inflammation Research Section (CIRS), National Heart, Lung and Blood Institute, Bethesda, MD, United States
| | - Claudia Kemper
- Complement and Inflammation Research Section (CIRS), National Heart, Lung and Blood Institute, Bethesda, MD, United States.,Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| |
Collapse
|
5
|
Mellors J, Tipton T, Longet S, Carroll M. Viral Evasion of the Complement System and Its Importance for Vaccines and Therapeutics. Front Immunol 2020; 11:1450. [PMID: 32733480 PMCID: PMC7363932 DOI: 10.3389/fimmu.2020.01450] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/04/2020] [Indexed: 12/17/2022] Open
Abstract
The complement system is a key component of innate immunity which readily responds to invading microorganisms. Activation of the complement system typically occurs via three main pathways and can induce various antimicrobial effects, including: neutralization of pathogens, regulation of inflammatory responses, promotion of chemotaxis, and enhancement of the adaptive immune response. These can be vital host responses to protect against acute, chronic, and recurrent viral infections. Consequently, many viruses (including dengue virus, West Nile virus and Nipah virus) have evolved mechanisms for evasion or dysregulation of the complement system to enhance viral infectivity and even exacerbate disease symptoms. The complement system has multifaceted roles in both innate and adaptive immunity, with both intracellular and extracellular functions, that can be relevant to all stages of viral infection. A better understanding of this virus-host interplay and its contribution to pathogenesis has previously led to: the identification of genetic factors which influence viral infection and disease outcome, the development of novel antivirals, and the production of safer, more effective vaccines. This review will discuss the antiviral effects of the complement system against numerous viruses, the mechanisms employed by these viruses to then evade or manipulate this system, and how these interactions have informed vaccine/therapeutic development. Where relevant, conflicting findings and current research gaps are highlighted to aid future developments in virology and immunology, with potential applications to the current COVID-19 pandemic.
Collapse
Affiliation(s)
- Jack Mellors
- Public Health England, National Infection Service, Salisbury, United Kingdom.,Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Tom Tipton
- Public Health England, National Infection Service, Salisbury, United Kingdom
| | - Stephanie Longet
- Public Health England, National Infection Service, Salisbury, United Kingdom
| | - Miles Carroll
- Public Health England, National Infection Service, Salisbury, United Kingdom
| |
Collapse
|
6
|
Ravizza T, Vezzani A. Pharmacological targeting of brain inflammation in epilepsy: Therapeutic perspectives from experimental and clinical studies. Epilepsia Open 2018; 3:133-142. [PMID: 30564772 PMCID: PMC6293065 DOI: 10.1002/epi4.12242] [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] [Accepted: 06/02/2018] [Indexed: 12/16/2022] Open
Abstract
Increasing evidence supports a pathogenic role of unabated neuroinflammation in various central nervous system (CNS) diseases, including epilepsy. Neuroinflammation is not a bystander phenomenon of the diseased brain tissue, but it may contribute to neuronal hyperexcitability underlying seizure generation, cell loss, and neurologic comorbidities. Several molecules, which constitute the inflammatory milieu in the epileptogenic area, activate signaling pathways in neurons and glia resulting in pathologic modifications of cell function, which ultimately lead to alterations in synaptic transmission and plasticity. Herein we report the up-to-date experimental and clinical evidence that supports the neuromodulatory role of inflammatory mediators, their related signaling pathways, and involvement in epilepsy. We discuss how these mechanisms can be harnessed to discover and validate targets for novel therapeutics, which may prevent or control pharmacoresistant epilepsies.
Collapse
Affiliation(s)
- Teresa Ravizza
- Department of NeuroscienceIRCCS – Mario Negri Institute for Pharmacological ResearchMilanoItaly
| | - Annamaria Vezzani
- Department of NeuroscienceIRCCS – Mario Negri Institute for Pharmacological ResearchMilanoItaly
| |
Collapse
|
7
|
Mahajan SD, Aalinkeel R, Parikh NU, Jacob A, Cwiklinski K, Sandhu P, Le K, Loftus AW, Schwartz SA, Quigg RJ, Alexander JJ. Immunomodulatory Role of Complement Proteins in the Neuropathology Associated with Opiate Abuse and HIV-1 Co-Morbidity. Immunol Invest 2018; 46:816-832. [PMID: 29058550 DOI: 10.1080/08820139.2017.1371891] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The complement system which is a critical mediator of innate immunity plays diverse roles in the neuropathogenesis of HIV-1 infection such as clearing HIV-1 and promoting productive HIV-1 replication. In the development of HIV-1 associated neurological disorders (HAND), there may be an imbalance between complement activation and regulation, which may contribute to the neuronal damage as a consequence of HIV-1 infection. It is well recognized that opiate abuse exacerbates HIV-1 neuropathology, however, little is known about the role of complement proteins in opiate induced neuromodulation, specifically in the presence of co-morbidity such as HIV-1 infection. Complement levels are significantly increased in the HIV-1-infected brain, thus HIV-induced complement synthesis may represent an important mechanism for the pathogenesis of AIDS in the brain, but remains underexplored. Anti-HIV-1 antibodies are able to initiate complement activation in HIV-1 infected CNS cells such as microglia and astrocytes during the course of disease progression; however, this complement activation fails to clear and eradicate HIV-1 from infected cells. In addition, the antiretroviral agents used for HIV therapy cause dysregulation of lipid metabolism, endothelial, and adipocyte cell function, and activation of pro-inflammatory cytokines. We speculate that both HIV-1 and opiates trigger a cytokine-mediated pro-inflammatory stimulus that modulates the complement cascade to exacerbate the virus-induced neurological damage. We examined the expression levels of C1q, SC5b-9, C5L2, C5aR, C3aR, and C9 key members of the complement cascade both in vivo in post mortem brain frontal cortex tissue from patients with HAND who used/did not use heroin, and in vitro using human microglial cultures treated with HIV tat and/or heroin. We observed significant expression of C1q and SC5b-9 by immunofluorescence staining in both the brain cortical and hippocampal region in HAND patients who abused heroin. Additionally, we observed increased gene expression of C5aR, C3aR, and C9 in the brain tissue of both HIV-1 infected patients with HAND who abused and did not abuse heroin, as compared to HIV negative controls. Our results show a significant increase in the expression of complement proteins C9, C5L2, C5aR, and C3aR in HIV transfected microglia and an additional increase in the levels of these complement proteins in heroin-treated HIV transfected microglia. This study highlights the a) potential roles of complement proteins in the pathogenesis of HIV-1-related neurodegenerative disorders; b) the combined effect of an opiate, like heroin, and HIV viral protein like HIV tat on complement proteins in normal human microglial cells and HIV transfected microglial cells. In the context of HAND, targeting selective steps in the complement cascade could help ameliorating the HIV burden in the CNS, thus investigations of complement-related therapeutic approaches for the treatment of HAND are warranted.
Collapse
Affiliation(s)
- Supriya D Mahajan
- a SUNY University at Buffalo , Department of Medicine, Division of Allergy, Immunology & Rheumatology , Buffalo , NY , USA
| | - Ravikumar Aalinkeel
- a SUNY University at Buffalo , Department of Medicine, Division of Allergy, Immunology & Rheumatology , Buffalo , NY , USA
| | - Neil U Parikh
- a SUNY University at Buffalo , Department of Medicine, Division of Allergy, Immunology & Rheumatology , Buffalo , NY , USA
| | - Alexander Jacob
- b Division of Nephrology , UB Clinical and Translational Research Center , Buffalo , NY , USA
| | - Katherine Cwiklinski
- a SUNY University at Buffalo , Department of Medicine, Division of Allergy, Immunology & Rheumatology , Buffalo , NY , USA
| | - Prateet Sandhu
- a SUNY University at Buffalo , Department of Medicine, Division of Allergy, Immunology & Rheumatology , Buffalo , NY , USA
| | - Kevin Le
- a SUNY University at Buffalo , Department of Medicine, Division of Allergy, Immunology & Rheumatology , Buffalo , NY , USA
| | - Alexander W Loftus
- a SUNY University at Buffalo , Department of Medicine, Division of Allergy, Immunology & Rheumatology , Buffalo , NY , USA
| | - Stanley A Schwartz
- a SUNY University at Buffalo , Department of Medicine, Division of Allergy, Immunology & Rheumatology , Buffalo , NY , USA
| | - Richard J Quigg
- b Division of Nephrology , UB Clinical and Translational Research Center , Buffalo , NY , USA
| | - Jessy J Alexander
- b Division of Nephrology , UB Clinical and Translational Research Center , Buffalo , NY , USA
| |
Collapse
|
8
|
Morgan BP. Complement in the pathogenesis of Alzheimer's disease. Semin Immunopathol 2018; 40:113-124. [PMID: 29134267 PMCID: PMC5794825 DOI: 10.1007/s00281-017-0662-9] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/01/2017] [Indexed: 12/19/2022]
Abstract
The emergence of complement as an important player in normal brain development and pathological remodelling has come as a major surprise to most scientists working in neuroscience and almost all those working in complement. That a system, evolved to protect the host against infection, should have these unanticipated roles has forced a rethink about what complement might be doing in the brain in health and disease, where it is coming from, and whether we can, or indeed should, manipulate complement in the brain to improve function or restore homeostasis. Complement has been implicated in diverse neurological and neuropsychiatric diseases well reviewed elsewhere, from depression through epilepsy to demyelination and dementia, in most complement drives inflammation to exacerbate the disease. Here, I will focus on just one disease, the most common cause of dementia, Alzheimer's disease. I will briefly review the current understanding of what complement does in the normal brain, noting, in particular, the many gaps in understanding, then describe how complement may influence the genesis and progression of pathology in Alzheimer's disease. Finally, I will discuss the problems and pitfalls of therapeutic inhibition of complement in the Alzheimer brain.
Collapse
Affiliation(s)
- B Paul Morgan
- Systems Immunity Research Institute and Dementia Research Institute Cardiff, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK.
| |
Collapse
|
9
|
Fonseca MI, Chu SH, Hernandez MX, Fang MJ, Modarresi L, Selvan P, MacGregor GR, Tenner AJ. Cell-specific deletion of C1qa identifies microglia as the dominant source of C1q in mouse brain. J Neuroinflammation 2017; 14:48. [PMID: 28264694 PMCID: PMC5340039 DOI: 10.1186/s12974-017-0814-9] [Citation(s) in RCA: 224] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/07/2017] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND The complement cascade not only provides protection from infection but can also mediate destructive inflammation. Complement is also involved in elimination of neuronal synapses which is essential for proper development, but can be detrimental during aging and disease. C1q, required for several of these complement-mediated activities, is present in the neuropil, microglia, and a subset of interneurons in the brain. METHODS To identify the source(s) of C1q in the brain, the C1qa gene was selectively inactivated in the microglia or Thy-1+ neurons in both wild type mice and a mouse model of Alzheimer's disease (AD), and C1q synthesis assessed by immunohistochemistry, QPCR, and western blot analysis. RESULTS While C1q expression in the brain was unaffected after inactivation of C1qa in Thy-1+ neurons, the brains of C1qa FL/FL :Cx3cr1 CreERT2 mice in which C1qa was ablated in microglia were devoid of C1q with the exception of limited C1q in subsets of interneurons. Surprisingly, this loss of C1q occurred even in the absence of tamoxifen by 1 month of age, demonstrating that Cre activity is tamoxifen-independent in microglia in Cx3cr1 CreERT2/WganJ mice. C1q expression in C1qa FL/FL : Cx3cr1 CreERT2/WganJ mice continued to decline and remained almost completely absent through aging and in AD model mice. No difference in C1q was detected in the liver or kidney from C1qa FL/FL : Cx3cr1 CreERT2/WganJ mice relative to controls, and C1qa FL/FL : Cx3cr1 CreERT2/WganJ mice had minimal, if any, reduction in plasma C1q. CONCLUSIONS Thus, microglia, but not neurons or peripheral sources, are the dominant source of C1q in the brain. While demonstrating that the Cx3cr1 CreERT2/WganJ deleter cannot be used for adult-induced deletion of genes in microglia, the model described here enables further investigation of physiological roles of C1q in the brain and identification of therapeutic targets for the selective control of complement-mediated activities contributing to neurodegenerative disorders.
Collapse
Affiliation(s)
- Maria I Fonseca
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697, USA
| | - Shu-Hui Chu
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697, USA
| | - Michael X Hernandez
- Department of Pathology and Laboratory Medicine, University of California, Irvine School of Medicine, Irvine, CA, 92697, USA
| | - Melody J Fang
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697, USA
| | - Lila Modarresi
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697, USA
| | - Pooja Selvan
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697, USA
| | - Grant R MacGregor
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, 92697, USA
| | - Andrea J Tenner
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697, USA. .,Department of Pathology and Laboratory Medicine, University of California, Irvine School of Medicine, Irvine, CA, 92697, USA. .,Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, 92697, USA.
| |
Collapse
|
10
|
Association Between Microglia, Inflammatory Factors, and Complement with Loss of Hippocampal Mossy Fiber Synapses Induced by Trimethyltin. Neurotox Res 2016; 30:53-66. [PMID: 26892644 DOI: 10.1007/s12640-016-9606-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 12/16/2022]
Abstract
Complement-associated factors are implicated in pathogen presentation, neurodegeneration, and microglia resolution of tissue injury. To characterize complement activation with microglial clearance of degenerating mossy fiber boutons, hippocampal dentate granule neurons were ablated in CD-1 mice with trimethyltin (TMT; 2.2 mg/kg, i.p.). Neuronal apoptosis was accompanied by amoeboid microglia and elevations in tumor necrosis factor [Tnfa], interleukin 1β [Il1b], and Il6 mRNA and C1q protein. Inos mRNA levels were unaltered. Silver degeneration and synaptophysin staining indicated loss of synaptic innervation to CA3 pyramidal neurons. Reactive microglia with thickened bushy morphology showed co-localization of synaptophysin+ fragments. The initial response at 2 days post-TMT included transient elevations in Tnfa, Il1b, Il6, and Inos mRNA levels. A concurrent increase at 2 days was observed in arginase-1 [Arg1], Il10, transforming growth factor β1 [Tgfb1], and chitinase 3 like-3 [Ym1] mRNA levels. At 2 days, C1q protein was evident in the CA3 with elevated C1qa, C1qb, C3, Cr3a, and Cr3b mRNA levels. mRNA levels remained elevated at 5 days, returning to control by 14 days, corresponding to silver degeneration. mRNA levels for pentraxin3 (Ptx3) were elevated on day 2 and Ptx1 was not altered. Our data suggest an association between microglia reactivity, the induction of anti-inflammatory genes concurrent with pro-inflammatory genes and the expression of complement-associated factors with the degeneration of synapses following apoptotic neuronal loss.
Collapse
|
11
|
Wu F, Zou Q, Ding X, Shi D, Zhu X, Hu W, Liu L, Zhou H. Complement component C3a plays a critical role in endothelial activation and leukocyte recruitment into the brain. J Neuroinflammation 2016; 13:23. [PMID: 26822321 PMCID: PMC4731990 DOI: 10.1186/s12974-016-0485-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 01/18/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The complement system is becoming increasingly recognized as a key participant in many neurodegenerative diseases of the brain. Complement-deficient animals exhibit reduced neuroinflammation. METHODS In the present study, we administered intracerebroventricularly lipopolysaccharide (LPS) to mimic local infection of the brain and investigated the role of key complement component C3 in brain vasculature endothelial activation and leukocyte recruitment. The degree of neutrophil infiltration was determined by esterase staining. Leukocyte-endothelial interactions were measured using intravital microscopy. Cerebral endothelial activation was evaluated using real-time PCR and Western blotting. RESULTS Neutrophil infiltration into the brain cortex and hippocampus was significantly reduced in C3(-/-) mice and C3aR(-/-) mice but not in C6(-/-) mice. We detected markedly attenuated leukocyte-endothelial interactions in the brain microvasculature of C3(-/-) mice. Accordingly, in response to LPS administration, the brain microvasculature in these mice had decreased expression of P-selectin, E-selectin, intercellular cell adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1). Depletion of C3 from the circulation also caused reduction in VCAM-1 and E-selectin expression and leukocyte recruitment, suggesting that C3 in the circulation contributed to brain endothelial activation. Furthermore, C3(-/-) mice exhibited decreased leukocyte recruitment into the brain upon tumor necrosis factor-α (TNF-α) stimulation. C3a activated the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) and induced the upregulation of VCAM-1 and ICAM-1 expression in murine primary cerebral endothelial cells in vitro. CONCLUSIONS Our study provides the first evidence that C3a plays a critical role in cerebral endothelial activation and leukocyte recruitment during inflammation in the brain.
Collapse
Affiliation(s)
- Fengjiao Wu
- Department of Immunology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, JS, 210029, China.
| | - Qiang Zou
- Department of Immunology, Chengdu Medical College, Chengdu, 610083, Sichuan, China.
| | - Xiaodan Ding
- Department of Immunology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, JS, 210029, China.
| | - Dongyan Shi
- Department of Immunology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, JS, 210029, China.
| | - Xingxing Zhu
- Department of Immunology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, JS, 210029, China.
| | - Weiguo Hu
- Shanghai Cancer Center and Institute of Biomedical Science, Shanghai Medical College, Shanghai Cancer Center, Fudan University, Shanghai, 200032, China.
| | - Lixin Liu
- Department of Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E5, Canada.
| | - Hong Zhou
- Department of Immunology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, JS, 210029, China.
| |
Collapse
|
12
|
Neely BA, Soper JL, Gulland FMD, Bell PD, Kindy M, Arthur JM, Janech MG. Proteomic analysis of cerebrospinal fluid in California sea lions (Zalophus californianus) with domoic acid toxicosis identifies proteins associated with neurodegeneration. Proteomics 2015; 15:4051-63. [DOI: 10.1002/pmic.201500167] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/10/2015] [Accepted: 09/09/2015] [Indexed: 12/29/2022]
Affiliation(s)
- Benjamin A. Neely
- Department of Medicine; Division of Nephrology; Medical University of South Carolina; Charleston SC USA
| | | | | | - P. Darwin Bell
- Department of Medicine; Division of Nephrology; Medical University of South Carolina; Charleston SC USA
| | - Mark Kindy
- Marine Biomedicine and Environmental Sciences Center; Medical University of South Carolina; Charleston SC USA
- Department of Regenerative Medicine and Cell Biology; Medical University of South Carolina; Charleston SC USA
- Department of Veterans’ Affairs; Research Service; Charleston SC USA
| | - John M. Arthur
- Department of Internal Medicine; Division of Nephrology; University of Arkansas for Medical Sciences; Little Rock AR USA
| | - Michael G. Janech
- Department of Medicine; Division of Nephrology; Medical University of South Carolina; Charleston SC USA
- Marine Biomedicine and Environmental Sciences Center; Medical University of South Carolina; Charleston SC USA
| |
Collapse
|
13
|
Hernandez-Encinas E, Aguilar-Morante D, Cortes-Canteli M, Morales-Garcia JA, Gine E, Santos A, Perez-Castillo A. CCAAT/enhancer binding protein β directly regulates the expression of the complement component 3 gene in neural cells: implications for the pro-inflammatory effects of this transcription factor. J Neuroinflammation 2015; 12:14. [PMID: 25617152 PMCID: PMC4348118 DOI: 10.1186/s12974-014-0223-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 12/16/2014] [Indexed: 11/10/2022] Open
Abstract
Background The CCAAT/enhancer-binding protein β (C/EBPβ) is a transcription factor, which was first identified as a regulator of differentiation and inflammatory processes mainly in adipose tissue and liver; however, its function in the brain was largely unknown for many years. Previous studies from our laboratory indicated that C/EBPβ is implicated in inflammatory process and brain injury, since mice lacking this gene were less susceptible to kainic acid-induced injury. Methods We first performed cDNA microarrays analysis using hippocampal RNA isolated from C/EBPβ+/+ and C/EBPβ−/− mice. Immunocytochemical and immunohistochemical studies were done to evaluate C/EBPβ and C3 levels. Transient transfection experiments were made to analyze transcriptional regulation of C3 by C/EBPβ. To knockdown C/EBPβ and C3 expression, mouse astrocytes were infected with lentiviral particles expressing an shRNA specific for C/EBPβ or an siRNA specific for C3. Results Among the genes displaying significant changes in expression was complement component 3 (C3), which showed a dramatic decrease in mRNA content in the hippocampus of C/EBPβ−/− mice. C3 is the central component of the complement and is implicated in different brain disorders. In this work we have found that C/EBPβ regulates C3 levels in rodents glial in vitro and in the rat Substantia nigra pars compacta (SNpc) in vivo following an inflammatory insult. Analysis of the mouse C3 promoter showed that it is directly regulated by C/EBPβ through a C/EBPβ consensus site located at position −616/-599 of the gene. In addition, we show that depletion of C/EBPβ by a specific shRNA results in a significant decrease in the levels of C3 together with a reduction in the increased levels of pro-inflammatory agents elicited by lipopolysaccharide treatment. Conclusions Altogether, these results indicate that C3 is a downstream target of C/EBPβ, and it could be a mediator of the pro-inflammatory effects of this transcription factor in neural cells.
Collapse
Affiliation(s)
- Elena Hernandez-Encinas
- Instituto de Investigaciones Biomédicas, (CSIC-UAM), Arturo Duperier, 4, 28029, Madrid, Spain. .,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain.
| | - Diana Aguilar-Morante
- Instituto de Investigaciones Biomédicas, (CSIC-UAM), Arturo Duperier, 4, 28029, Madrid, Spain. .,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain.
| | - Marta Cortes-Canteli
- Instituto de Investigaciones Biomédicas, (CSIC-UAM), Arturo Duperier, 4, 28029, Madrid, Spain. .,Present address: Laboratory of Neurobiology and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.
| | - Jose A Morales-Garcia
- Instituto de Investigaciones Biomédicas, (CSIC-UAM), Arturo Duperier, 4, 28029, Madrid, Spain. .,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain.
| | - Elena Gine
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain. .,Departamento de Bioquímica y Biologia Molecular, Facultad de Medicina, UCM, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.
| | - Angel Santos
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain. .,Departamento de Bioquímica y Biologia Molecular, Facultad de Medicina, UCM, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.
| | - Ana Perez-Castillo
- Instituto de Investigaciones Biomédicas, (CSIC-UAM), Arturo Duperier, 4, 28029, Madrid, Spain. .,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain.
| |
Collapse
|
14
|
Xu D, Miller SD, Koh S. Immune mechanisms in epileptogenesis. Front Cell Neurosci 2013; 7:195. [PMID: 24265605 PMCID: PMC3821015 DOI: 10.3389/fncel.2013.00195] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 10/08/2013] [Indexed: 01/03/2023] Open
Abstract
Epilepsy is a chronic brain disorder that affects 1% of the human population worldwide. Immune responses are implicated in seizure induction and the development of epilepsy. Pre-clinical and clinical evidence have accumulated to suggest a positive feedback cycle between brain inflammation and epileptogenesis. Prolonged or recurrent seizures and brain injuries lead to upregulation of proinflammatory cytokines and activated immune responses to further increase seizure susceptibility, promote neuronal excitability, and induce blood-brain barrier breakdown. This review focuses on the potential role of innate and adaptive immune responses in the pathogenesis of epilepsy. Both human studies and animal models that help delineate the contributions of brain inflammation in epileptogenesis will be discussed. We highlight the critical role of brain-resident immune mediators and emphasize the contribution of brain-infiltrating peripheral leukocytes. Additionally, we propose possible immune mechanisms that underlie epileptogenesis. Several proinflammatory pathways are discussed, including the interleukin-1 receptor/toll-like receptor signaling cascade, the pathways activated by damage-associated molecular patterns, and the cyclooxygenase-2/prostaglandin pathway. Finally, development of better therapies that target the key constituents and processes identified in these mechanisms are considered, for instance, engineering antagonizing agents that effectively block these pathways in an antigen-specific manner.
Collapse
Affiliation(s)
- Dan Xu
- Department of Microbiology-Immunology and Interdepartmental Immunobiology, Feinberg School of Medicine, Northwestern UniversityChicago IL, USA
- Department of Pediatrics, Division of Neurobiology, Children’s Research Center, Lurie Children’s Hospital of ChicagoChicago IL, USA
| | - Stephen D. Miller
- Department of Microbiology-Immunology and Interdepartmental Immunobiology, Feinberg School of Medicine, Northwestern UniversityChicago IL, USA
| | - Sookyong Koh
- Department of Pediatrics, Division of Neurobiology, Children’s Research Center, Lurie Children’s Hospital of ChicagoChicago IL, USA
- Department of Pediatrics, Feinberg School of Medicine, Northwestern UniversityChicago IL, USA
| |
Collapse
|
15
|
Pharmacological blockade of IL-1β/IL-1 receptor type 1 axis during epileptogenesis provides neuroprotection in two rat models of temporal lobe epilepsy. Neurobiol Dis 2013; 59:183-93. [PMID: 23938763 DOI: 10.1016/j.nbd.2013.07.015] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 07/29/2013] [Indexed: 02/06/2023] Open
Abstract
We studied whether pharmacological blockade of the IL-1β-mediated signaling, rapidly activated in forebrain by epileptogenic injuries, affords neuroprotection in two different rat models of status epilepticus (SE). As secondary outcome, we measured treatment's effect on SE-induced epileptogenesis. IL-1β signaling was blocked by systemic administration of two antiinflammatory drugs, namely human recombinant IL-1 receptor antagonist (anakinra), the naturally occurring and clinically used competitive IL-1 receptor type 1 antagonist, and VX-765 a specific non-peptide inhibitor of IL-1β cleavage and release. Antiinflammatory drugs were given 60min after antiepileptic (AED) drug-controlled SE induced by pilocarpine, or 180min after unrestrained electrical SE, for 7days using a protocol yielding therapeutic drug levels in brain. This drug combination significantly decreased both IL-1β expression in astrocytes and cell loss in rat forebrain. Neuroprotection and the antiinflammatory effect were more pronounced in the electrical SE model. Onset of epilepsy, and frequency and duration of seizures 3months after electrical SE were not significantly modified. Transcriptomic analysis in the hippocampus showed that the combined treatment did not affect the broad inflammatory response induced by SE during epileptogenesis. In particular, the treatment did not prevent the induction of the complement system and Toll-like receptors, both contributing to cell loss and seizure generation. We conclude that the IL-1β signaling represents an important target for reducing cell loss after SE. The data highlight a new class of clinically tested agents affording neuroprotection after a delayed post-injury intervention. Earlier blockade of this rapid onset inflammatory pathway during SE, or concomitant treatment with antiinflammatory drugs targeting additional components of the broad inflammatory response to SE, or co-treatment with AEDs, is likely to be required for optimizing beneficial outcomes.
Collapse
|
16
|
Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milan, Italy.
| | | | | |
Collapse
|
17
|
Veerhuis R, Nielsen HM, Tenner AJ. Complement in the brain. Mol Immunol 2011; 48:1592-603. [PMID: 21546088 DOI: 10.1016/j.molimm.2011.04.003] [Citation(s) in RCA: 293] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 04/04/2011] [Accepted: 04/04/2011] [Indexed: 01/24/2023]
Abstract
The brain is considered to be an immune privileged site, because the blood-brain barrier limits entry of blood borne cells and proteins into the central nervous system (CNS). As a result, the detection and clearance of invading microorganisms and senescent cells as well as surplus neurotransmitters, aged and glycated proteins, in order to maintain a healthy environment for neuronal and glial cells, is largely confined to the innate immune system. In recent years it has become clear that many factors of innate immunity are expressed throughout the brain. Neuronal and glial cells express Toll like receptors as well as complement receptors, and virtually all complement components can be locally produced in the brain, often in response to injury or developmental cues. However, as inflammatory reactions could interfere with proper functioning of the brain, tight and fine tuned regulatory mechanisms are warranted. In age related diseases, such as Alzheimer's disease (AD), accumulating amyloid proteins elicit complement activation and a local, chronic inflammatory response that leads to attraction and activation of glial cells that, under such activation conditions, can produce neurotoxic substances, including pro-inflammatory cytokines and oxygen radicals. This process may be exacerbated by a disturbed balance between complement activators and complement regulatory proteins such as occurs in AD, as the local synthesis of these proteins is differentially regulated by pro-inflammatory cytokines. Much knowledge about the role of complement in neurodegenerative diseases has been derived from animal studies with transgenic overexpressing or knockout mice for specific complement factors or receptors. These studies have provided insight into the potential therapeutic use of complement regulators and complement receptor antagonists in chronic neurodegenerative diseases as well as in acute conditions, such as stroke. Interestingly, recent animal studies have also indicated that complement activation products are involved in brain development and synapse formation. Not only are these findings important for the understanding of how brain development and neural network formation is organized, it may also give insights into the role of complement in processes of neurodegeneration and neuroprotection in the injured or aged and diseased adult central nervous system, and thus aid in identifying novel and specific targets for therapeutic intervention.
Collapse
Affiliation(s)
- Robert Veerhuis
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
| | | | | |
Collapse
|
18
|
Abstract
Epilepsy is the third most common chronic brain disorder, and is characterized by an enduring predisposition to generate seizures. Despite progress in pharmacological and surgical treatments of epilepsy, relatively little is known about the processes leading to the generation of individual seizures, and about the mechanisms whereby a healthy brain is rendered epileptic. These gaps in our knowledge hamper the development of better preventive treatments and cures for the approximately 30% of epilepsy cases that prove resistant to current therapies. Here, we focus on the rapidly growing body of evidence that supports the involvement of inflammatory mediators-released by brain cells and peripheral immune cells-in both the origin of individual seizures and the epileptogenic process. We first describe aspects of brain inflammation and immunity, before exploring the evidence from clinical and experimental studies for a relationship between inflammation and epilepsy. Subsequently, we discuss how seizures cause inflammation, and whether such inflammation, in turn, influences the occurrence and severity of seizures, and seizure-related neuronal death. Further insight into the complex role of inflammation in the generation and exacerbation of epilepsy should yield new molecular targets for the design of antiepileptic drugs, which might not only inhibit the symptoms of this disorder, but also prevent or abrogate disease pathogenesis.
Collapse
Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Via Giuseppe La Masa 19, 20156 Milan, Italy.
| | | | | | | |
Collapse
|
19
|
Vezzani A. Innate immunity and inflammation in temporal lobe epilepsy: new emphasis on the role of complement activation. Epilepsy Curr 2010; 8:75-7. [PMID: 18488060 DOI: 10.1111/j.1535-7511.2008.00243.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Complement Activation in Experimental and Human Temporal Lobe Epilepsy. Aronica E, Boer K, van Vliet EA, RedekerS, Baayen JC, Spliet WG, van Rijen PC, Troost D, da Silva FH, Wadman WJ, Gorter JA. Neurobiol Dis 2007;26(3):497–511. We investigated the involvement of the complement cascade during epileptogenesis in a rat model of temporal lobe epilepsy (TLE), and in the chronic epileptic phase in both experimental as well as human TLE. Previous rat gene expression analysis using microarrays indicated prominent activation of the classical complement pathway which peaked at 1 week after SE in CA3 and entorhinal cortex. Increased expression of C1q, C3 and C4 was confirmed in CA3 tissue using quantitative PCR at 1 day, 1 week and 3–4 months after status epilepticus (SE). Upregulation of C1q and C3d protein expression was confirmed mainly to be present in microglia and in a few hippocampal neurons. In human TLE with hippocampal sclerosis, astroglial, microglial and neuronal (5/8 cases) expression of C1q, C3c and C3d was observed particularly within regions where neuronal cell loss occurs. The membrane attack protein complex (C5b-C9) was predominantly detected in activated microglial cells. The persistence of complement activation could contribute to a sustained inflammatory response and could destabilize neuronal networks involved.
Collapse
|
20
|
Abstract
Excessive CNS synapses are eliminated during development to establish mature patterns of neuronal connectivity. A complement cascade protein, C1q, is involved in this process. Mice deficient in C1q fail to refine retinogeniculate connections resulting in excessive retinal innervation of lateral geniculate neurons. We hypothesized that C1q knockout (KO) mice would exhibit defects in neocortical synapse elimination resulting in enhanced excitatory synaptic connectivity and epileptiform activity. We recorded spontaneous and evoked field potential activity in neocortical slices and obtained video-EEG recordings from implanted C1q KO and wild-type (WT) mice. We also used laser scanning photostimulation of caged glutamate and whole cell recordings to map excitatory and inhibitory synaptic connectivity. Spontaneous and evoked epileptiform field potentials occurred at multiple sites in neocortical slices from C1q KO, but not WT mice. Laser mapping experiments in C1q KO slices showed that the proportion of glutamate uncaging sites from which excitatory postsynaptic currents (EPSCs) could be evoked ("hotspot ratio") increased significantly in layer IV and layer V, although EPSC amplitudes were unaltered. Density of axonal boutons was significantly increased in layer V pyramidal neurons of C1q KO mice. Implanted KO mice had frequent behavioral seizures consisting of behavioral arrest associated with bihemispheric spikes and slow wave activity lasting from 5 to 30 s. Results indicate that epileptogenesis in C1q KO mice is related to a genetically determined failure to prune excessive excitatory synapses during development.
Collapse
|
21
|
Abstract
Brain injury may result in the development of epilepsy, one of the most common neurological disorders. We previously demonstrated that albumin is critical in the generation of epilepsy after blood-brain barrier (BBB) compromise. Here, we identify TGF-beta pathway activation as the underlying mechanism. We demonstrate that direct activation of the TGF-beta pathway by TGF-beta1 results in epileptiform activity similar to that after exposure to albumin. Coimmunoprecipitation revealed binding of albumin to TGF-beta receptor II, and Smad2 phosphorylation confirmed downstream activation of this pathway. Transcriptome profiling demonstrated similar expression patterns after BBB breakdown, albumin, and TGF-beta1 exposure, including modulation of genes associated with the TGF-beta pathway, early astrocytic activation, inflammation, and reduced inhibitory transmission. Importantly, TGF-beta pathway blockers suppressed most albumin-induced transcriptional changes and prevented the generation of epileptiform activity. Our present data identifies the TGF-beta pathway as a novel putative epileptogenic signaling cascade and therapeutic target for the prevention of injury-induced epilepsy.
Collapse
|
22
|
Alexander JJ, Anderson AJ, Barnum SR, Stevens B, Tenner AJ. The complement cascade: Yin-Yang in neuroinflammation--neuro-protection and -degeneration. J Neurochem 2008; 107:1169-87. [PMID: 18786171 DOI: 10.1111/j.1471-4159.2008.05668.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The complement cascade has long been recognized to play a key role in inflammatory and degenerative diseases. It is a 'double edged' sword as it is necessary to maintain health, yet can have adverse effects when unregulated, often exacerbating disease. The contrasting effects of complement, depending on whether in a setting of health or disease, is the price paid to achieve flexibility in scope and degree of a protective response for the host from infection and injury. Loss or even decreased efficiency of critical regulatory control mechanisms can result in aggravated inflammation and destruction of self-tissue. The role of the complement cascade is poorly understood in the nervous system and neurological disorders. Novel studies have demonstrated that the expression of complement proteins in brain varies in different cell types and the effects of complement activation in various disease settings appear to differ. Understanding the functioning of this cascade is essential, as it has therapeutic implications. In this review, we will attempt to provide insight into how this complex cascade functions and to identify potential strategic targets for therapeutic intervention in chronic diseases as well as acute injury in the CNS.
Collapse
|
23
|
Zhou J, Fonseca MI, Pisalyaput K, Tenner AJ. Complement C3 and C4 expression in C1q sufficient and deficient mouse models of Alzheimer's disease. J Neurochem 2008; 106:2080-92. [PMID: 18624920 DOI: 10.1111/j.1471-4159.2008.05558.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease resulting in progressive cognitive decline. Amyloid plaque deposits consisting specifically of beta-amyloid peptides that have formed fibrils displaying beta-pleated sheet conformation are associated with activated microglia and astrocytes, are colocalized with C1q and other complement activation products, and appear at the time of cognitive decline in AD. Amyloid precursor protein (APP) transgenic mouse models of AD that lack the ability to activate the classical complement pathway display less neuropathology than do the APPQ+/+ mice, consistent with the hypothesis that complement activation and the resultant inflammation may play a role in the pathogenesis of AD. Further investigation of the presence of complement proteins C3 and C4 in the brain of these mice demonstrate that both C3 and C4 deposition increase with age in APPQ+/+ transgenic mice, as expected with the age-dependent increase in fibrillar beta-amyloid deposition. In addition, while C4 is predominantly localized on the plaques and/or associated with oligodendrocytes in APPQ+/+ mice, little C4 is detected in APPQ-/- brains consistent with a lack of classical complement pathway activation because of the absence of C1q in these mice. In contrast, plaque and cell associated C3 immunoreactivity is seen in both animal models and, surprisingly, is higher in APPQ-/- than in APPQ+/+ mice, providing evidence for alternative pathway activation. The unexpected increase in C3 levels in the APPQ-/- mice coincident with decreased neuropathology provides support for the hypothesis that complement can mediate protective events as well as detrimental events in this disease. Finally, induced expression of C3 in a subset of astrocytes suggests the existence of differential activation states of these cells.
Collapse
Affiliation(s)
- Jun Zhou
- Department of Molecular Biology and Biochemistry, Institute for Brain Aging and Dementia, Center for Immunology, University of California, Irvine, California 92697-3900, USA
| | | | | | | |
Collapse
|
24
|
Morita H, Suzuki K, Mori N, Yasuhara O. Occurrence of complement protein C3 in dying pyramidal neurons in rat hippocampus after systemic administration of kainic acid. Neurosci Lett 2006; 409:35-40. [PMID: 17014960 DOI: 10.1016/j.neulet.2006.09.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Revised: 09/06/2006] [Accepted: 09/07/2006] [Indexed: 10/24/2022]
Abstract
To evaluate the roles of complement in kainic acid (KA)-induced neuronal damages, the immunohistochemical localization of the complement protein C3 was examined in rat hippocampus after systemic KA injection. The immunoreactivity for C3 was found in glial cells in control rats, and such glial cells were increased in number after KA injection. Our confocal study showed that C3-positive glial cells were microglia. Three to seven days after KA, C3 immunoreactivity appeared in CA1 and CA3 pyramidal neurons. Double staining for C3 combined with the terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling showed that occurrence of C3 immunoreactivity in neurons coincided well with that of DNA fragmentation. Western blot analysis and RT-PCR experiments suggested local synthesis of C3 by brain cells. Our results suggest that C3 contributes greatly to neuronal death after systemic KA administration, and that microglia and neurons are the local source of C3 in KA-induced brain injury.
Collapse
Affiliation(s)
- Hiroyuki Morita
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga 520-2192, Japan
| | | | | | | |
Collapse
|
25
|
Xie Z, Harris-White ME, Wals PA, Frautschy SA, Finch CE, Morgan TE. Apolipoprotein J (clusterin) activates rodent microglia in vivo and in vitro. J Neurochem 2005; 93:1038-46. [PMID: 15857407 DOI: 10.1111/j.1471-4159.2005.03065.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Apolipoprotein J (apoJ; also known as clusterin and sulfated glycoprotein (SGP)-2) is associated with senile plaques in degenerating regions of Alzheimer's disease brains, where activated microglia are also prominent. We show a functional link between apoJ and activated microglia by demonstrating that exogenous apoJ activates rodent microglia in vivo and in vitro. Intracerebroventricular infusion of purified human plasma apoJ ( approximately 4 microg over 28 days) activated parenchymal microglia to a phenotype characterized by enlarged cell bodies and processes (phosphotyrosine immunostaining). In vitro, primary rat microglia were also activated by apoJ, with changes in morphology and induction of major histocompatibility complex class II (MHCII) antigen. ApoJ increased the secretion of reactive nitrogen intermediates in a dose-dependent manner (EC(50) 112 nm), which was completely blocked by aminoguanidine (AG), a nitric oxide synthase inhibitor. However, AG did not block the increased secretion of tumor necrosis factor-alpha by apoJ (EC(50) 55 nm). Microglial activation by apoJ was also blocked by an anti-apoJ monoclonal antibody (G7), and by chemical cleavage of apoJ with 2-nitro-5-thiocyanobenzoate. The mitogen-activated protein kinase kinase and protein kinase C inhibitors PD98059 and H7 inhibited apoJ-mediated induction of reactive nitrogen intermediate secretion from cultured microglia. As a functional measure, apoJ-activated microglia secreted neurotoxic agents in a microglia-neuron co-culture model. We hypothesize that ApoJ contributes to chronic inflammation and neurotoxicity through direct effects on microglia.
Collapse
Affiliation(s)
- Z Xie
- Andrus Gerontology Center and Department of Biological Sciences, University of Southern California, Los Angeles, 90089, USA
| | | | | | | | | | | |
Collapse
|
26
|
Anderson AJ, Najbauer J, Huang W, Young W, Robert S. Upregulation of complement inhibitors in association with vulnerable cells following contusion-induced spinal cord injury. J Neurotrauma 2005; 22:382-97. [PMID: 15785233 DOI: 10.1089/neu.2005.22.382] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have previously described the activation of the classical, alternative, and terminal complement cascade pathways after acute contusion spinal cord injury using the New York University (NYU) weight-drop impactor. In the present study, we examined the induction of protein regulators of the complement cascade, factor H (FH), and clusterin, in the same experimental paradigm. The spinal cord of laminectomized adult rats was subjected to mild or severe injury using impactor weight-drop heights of 12.5 and 50 mm, respectively. The spinal cords of control and injured animals were evaluated at 1, 7, and 42 days after injury. Immunocytochemistry revealed a robust increase in the numbers and intensity of staining of FH, and clusterin-positive cells in the injured cord at all three time points, with the highest increases observed at 1 and 42 days after injury. FH and clusterin-positive cells were observed among neurons as well as oligodendrocytes. The increased expression was detected both rostrally and caudally from the injury site, in the latter case at distances up to 20 mm. The precise biological significance of injury-induced upregulation of these proteins remains to be determined. However, FH and clusterin are potent regulators of complement activity targeting upstream (FH) and downstream (clusterin) molecules of the pro-inflammatory cascade, which could be of vital importance in preventing a "runaway" inflammatory reaction in the injured spinal cord.
Collapse
Affiliation(s)
- Aileen J Anderson
- Department of Physical Medicine and Rehabilitation, and the Reeve-Irvine Center, University of California, Irvine, California, USA.
| | | | | | | | | |
Collapse
|
27
|
Anderson AJ, Robert S, Huang W, Young W, Cotman CW. Activation of complement pathways after contusion-induced spinal cord injury. J Neurotrauma 2005; 21:1831-46. [PMID: 15684772 DOI: 10.1089/neu.2004.21.1831] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Previous studies have shown that a cellular inflammatory response is initiated, and inflammatory cytokines are synthesized, following experimental spinal cord injury (SCI). In the present study, we tested the hypothesis that the complement cascade, a major component of both the innate and adaptive immune response, is also activated following experimental SCI. We investigated the pathways, cellular localization, timecourse, and degree of complement activation in rat spinal cord following acute contusion-induced SCI using the New York University (NYU) weight drop impactor. Mild and severe injuries (12.5 and 50 mm drop heights) at 1, 7, and 42 days post injury time points were evaluated. Classical (C1q and C4), alternative (Factor B) and terminal (C5b-9) complement pathways were strongly activated within 1 day of SCI. Complement protein immunoreactivity was predominantly found in cell types vulnerable to degeneration, neurons and oligodendrocytes, and was not generally observed in inflammatory or astroglial cells. Surprisingly, immunoreactivity for complement proteins was also evident 6 weeks after injury, and complement activation was observed as far as 20 mm rostral to the site of injury. Axonal staining by C1q and Factor B was also observed, suggesting a potential role for the complement cascade in demyelination or axonal degeneration. These data support the hypothesis that complement activation plays a role in SCI.
Collapse
Affiliation(s)
- Aileen J Anderson
- Department of Physical Medicine and Rehabilitation, and the Reeve-Irvine Center, University of California, Irvine, California 92696-4540, USA.
| | | | | | | | | |
Collapse
|
28
|
Noh HS, Kim DW, Kang SS, Cho GJ, Choi WS. Ketogenic diet prevents clusterin accumulation induced by kainic acid in the hippocampus of male ICR mice. Brain Res 2005; 1042:114-8. [PMID: 15823260 DOI: 10.1016/j.brainres.2005.01.097] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 01/24/2005] [Accepted: 01/24/2005] [Indexed: 11/22/2022]
Abstract
We investigated the effect of ketogenic diet (KD) on clusterin accumulation in the kainic acid (KA)-induced seizure model. Two days after KA administration, strong clusterin-like immunoreactivity (IR) was detected in the hippocampus in the normal diet (ND)-fed mice. But in the KD-fed mice, few clusterin-like IR was detected. These results indicate that KD has neuroprotective effects throughout diminishing nuclear clusterin accumulation that is involved in caspase-3 independent cell death mechanism.
Collapse
Affiliation(s)
- Hae Sook Noh
- Department of Anatomy and Neurobiology, Institute of Health Science, College of Medicine, Gyeongsang National University, Chinju, Kyungnam 660-751, South Korea
| | | | | | | | | |
Collapse
|
29
|
Fan R, Tenner AJ. Differential regulation of Abeta42-induced neuronal C1q synthesis and microglial activation. J Neuroinflammation 2005; 2:1. [PMID: 15642121 PMCID: PMC545941 DOI: 10.1186/1742-2094-2-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Accepted: 01/10/2005] [Indexed: 11/26/2022] Open
Abstract
Expression of C1q, an early component of the classical complement pathway, has been shown to be induced in neurons in hippocampal slices, following accumulation of exogenous Aβ42. Microglial activation was also detected by surface marker expression and cytokine production. To determine whether C1q induction was correlated with intraneuronal Aβ and/or microglial activation, D-(-)-2-amino-5-phosphonovaleric acid (APV, an NMDA receptor antagonist) and glycine-arginine-glycine-aspartic acid-serine-proline peptide (RGD, an integrin receptor antagonist), which blocks and enhances Aβ42 uptake, respectively, were assessed for their effect on neuronal C1q synthesis and microglial activation. APV inhibited, and RGD enhanced, microglial activation and neuronal C1q expression. However, addition of Aβ10–20 to slice cultures significantly reduced Aβ42 uptake and microglial activation, but did not alter the Aβ42-induced neuronal C1q expression. Furthermore, Aβ10–20 alone triggered C1q production in neurons, demonstrating that neither neuronal Aβ42 accumulation, nor microglial activation is required for neuronal C1q upregulation. These data are compatible with the hypothesis that multiple receptors are involved in Aβ injury and signaling in neurons. Some lead to neuronal C1q induction, whereas other(s) lead to intraneuronal accumulation of Aβ and/or stimulation of microglia.
Collapse
Affiliation(s)
- Rong Fan
- Department of Molecular Biology and Biochemistry, Institute of Brain Aging and Dementia, University of California, Irvine, Irvine, CA 92697 USA
| | - Andrea J Tenner
- Department of Molecular Biology and Biochemistry, Institute of Brain Aging and Dementia, University of California, Irvine, Irvine, CA 92697 USA
| |
Collapse
|
30
|
Affiliation(s)
- K D Rainsford
- Biomedical Research Centre, Sheffield Hallam University, Sheffield S1 1WB, UK.
| |
Collapse
|
31
|
Loeffler DA. Using animal models to determine the significance of complement activation in Alzheimer's disease. J Neuroinflammation 2004; 1:18. [PMID: 15479474 PMCID: PMC529311 DOI: 10.1186/1742-2094-1-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Accepted: 10/12/2004] [Indexed: 12/11/2022] Open
Abstract
Complement inflammation is a major inflammatory mechanism whose function is to promote the removal of microorganisms and the processing of immune complexes. Numerous studies have provided evidence for an increase in this process in areas of pathology in the Alzheimer's disease (AD) brain. Because complement activation proteins have been demonstrated in vitro to exert both neuroprotective and neurotoxic effects, the significance of this process in the development and progression of AD is unclear. Studies in animal models of AD, in which brain complement activation can be experimentally altered, should be of value for clarifying this issue. However, surprisingly little is known about complement activation in the transgenic animal models that are popular for studying this disorder. An optimal animal model for studying the significance of complement activation on Alzheimer's – related neuropathology should have complete complement activation associated with senile plaques, neurofibrillary tangles (if present), and dystrophic neurites. Other desirable features include both classical and alternative pathway activation, increased neuronal synthesis of native complement proteins, and evidence for an increase in complement activation prior to the development of extensive pathology. In order to determine the suitability of different animal models for studying the role of complement activation in AD, the extent of complement activation and its association with neuropathology in these models must be understood.
Collapse
Affiliation(s)
- David A Loeffler
- Department of Neurology, William Beaumont Hospital Research Institute, Royal Oak, MI 48073, USA.
| |
Collapse
|
32
|
Lin B, Ritchie GD, Rossi J, Pancrazio JJ. Gene expression profiles in the rat central nervous system induced by JP-8 jet fuel vapor exposure. Neurosci Lett 2004; 363:233-8. [PMID: 15182950 DOI: 10.1016/j.neulet.2004.03.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Revised: 03/18/2004] [Accepted: 03/26/2004] [Indexed: 11/22/2022]
Abstract
Jet propulsion fuel-8 (JP-8) is the predominant fuel for military land vehicles and aircraft used in the US and NATO. Occupational exposure to jet fuel in military personnel has raised concern for the health risk associated with such exposure in the Department of Defense. Clinical studies of humans chronically exposed to jet fuel have suggested both neurotoxicity and neurobehavioral deficits. We utilized rat neurobiology U34 array to measure gene expression changes in whole brain tissue of rats exposed repeatedly to JP-8, under conditions that simulated possible occupational exposure (6 h/day for 91 days) to JP-8 vapor at 250, 500, and 1000 mg/m(3), respectively. Our studies revealed that the gene expression changes of exposure groups can be divided into two main categories according to their functions: (1). neurotransmitter signaling pathways; and (2). stress response. The implications of these gene expression changes are discussed.
Collapse
Affiliation(s)
- Baochuan Lin
- Center for Bio/Molecular Science & Engineering, Code 6900, Naval Research Laboratory, Washington, DC 20375, USA
| | | | | | | |
Collapse
|
33
|
Kassed CA, Butler TL, Patton GW, Demesquita DD, Navidomskis MT, Mémet S, Israël A, Pennypacker KR. Injury‐induced NF‐κB activation in the hippocampus: implications for neuronal survival. FASEB J 2004; 18:723-4. [PMID: 14766792 DOI: 10.1096/fj.03-0773fje] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nuclear factor (NF)-kappaB p50 protein is involved in promoting survival in hippocampal neurons after trimethyltin (TMT)-injury. In the current study, hippocampal NF-kappaB activity was examined and quantitated from transgenic kappaB-lacZ reporter mice after chemical-induced injury. NF-kappaB activity was localized primarily to hippocampal neurons and significantly elevated over that in saline-treated mice between 4 and 21 days after TMT injection. Seven days after TMT injection, a timepoint of elevated NF-kappaB activity, gene expression in the hippocampus was studied by microarray analysis through comparison of expression profiles between treated nontransgenic and p50-null mice with their saline-injected controls. Seventeen genes increased in nontransgenic TMT-treated mice relative to saline-treated as well as showing no increase in p50-null mice, indicating a role for p50 in their regulation. One of these genes, the Na+, K+-ATPase-gamma subunit, was detected in brain for the first time. Several of the genes modulated by NF-kappaB are potentially related to neuroplasticity, providing additional evidence that this transcription factor is a neuroprotective signal in the hippocampus.
Collapse
Affiliation(s)
- C A Kassed
- Department of Pharmacology and Therapeutics, University of South Florida, Tampa, Florida 33612, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Kim YS, Kim YH, Cheon EW, Park JM, Yoo JM, Kang SS, Cho GJ, Choi WS. Retinal expression of clusterin in the streptozotocin-induced diabetic rat. Brain Res 2003; 976:53-9. [PMID: 12763621 DOI: 10.1016/s0006-8993(03)02636-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To assess the possible relevance of clusterin in the pathophysiology of retinopathy associated with diabetes mellitus, streptozotocin-induced diabetic rats were studied. Clusterin expression was measured in both normal and streptozotocin-induced diabetic rat retinas using Northern blotting, reverse transcription polymerase chain reaction, immunohistochemistry and Western blot analysis. The results show increased clusterin protein level and its mRNA expression 6 weeks after induction of diabetes. Clusterin was localized to the inner nuclear and ganglion cell layers of both normal and diabetic rat retinas. These data show that diabetes affects the expression of clusterin in the retina and may reflect a diabetes-induced damage and/or alterations of neural structures resulting in diabetic retinopathy.
Collapse
Affiliation(s)
- Yoon Sook Kim
- Department of Anatomy and Neurobiology, Institute of Health Science, College of Medicine, Gyeongsang National University, Chilam-dong 92, Jinju, Kyungnam 660-751, South Korea
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Boyett KW, DiCarlo G, Jantzen PT, Jackson J, O'Leary C, Wilcock D, Morgan D, Gordon MN. Increased fibrillar beta-amyloid in response to human clq injections into hippocampus and cortex of APP+PS1 transgenic mice. Neurochem Res 2003; 28:83-93. [PMID: 12587666 DOI: 10.1023/a:1021600212829] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Human C1q when injected directly into hippocampus and cortex of doubly transgenic APP+PS1 mice results in the increase of Congo red-positive fibrillar deposits. Although there was no significant change in overall area stained for Abeta total, qualitatively it appeared that there was less diffuse Abeta in C1q-treated mice versus vehicle. There was no apparent change in astroglial or microglial activation caused by injection of C1q with respect to vehicle injections. These effects of C1q were only found in 50% BUB/BnJ mice, a strain with higher serum complement activity than other mouse lines. These in vivo data were consistent with the effects of C1q to increase fibrillogenesis of Abeta in vitro. In conclusion, complement protein C1q, believed to be involved in the pathogenesis of Alzheimer's disease in humans, can cause increased fibrillogenesis in the APP+PS1 mouse model of amyloid deposition.
Collapse
Affiliation(s)
- Kristal W Boyett
- Alzheimer's Research Laboratory, Department of Pharmacology and Therapeutics, Tampa, Florida 33612, USA
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Peroxynitrite mediates neurotoxicity of amyloid beta-peptide1-42- and lipopolysaccharide-activated microglia. J Neurosci 2002. [PMID: 11978825 DOI: 10.1523/jneurosci.22-09-03484.2002] [Citation(s) in RCA: 194] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The amyloid beta-peptide (Abeta) activates microglia and promotes the generation of cytokines and oxygen species, including nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha), which can be either neurotoxic or neuroprotective. We show that neuron death in cocultures of rat cortical microglia and neurons activated by lipopolysaccharide (LPS) or Abeta1-42 plus interferon gamma (IFNgamma) is caused by short-lived diffusible molecules and follows the generation of superoxide and/or peroxynitrite as determined by electron paramagnetic spectroscopy. Neurotoxicity induced by LPS or Abeta1-42 plus IFNgamma is blocked by inhibitors of NO synthesis and by the peroxynitrite (ONOO-) decomposition catalysts FeTMPyP [5,10,15,20-tetrakis(n-methyl-4'-pyridyl)porphinato iron (III) chloride] and FeTPPS [5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III) chloride] but not by the TNF-alpha inhibitor pentoxifylline. The specificity of FeTMPyP for ONOO- was confirmed by its ability to block the toxicity of a peroxynitrite donor but not of NO donors or of high levels of superoxide in a yeast mutant lacking superoxide dismutase 1. These results implicate peroxynitrite as a mediator of the toxicity of activated microglia, which may play a major role in Abeta1-42 neurotoxicity and Alzheimer's disease.
Collapse
|
37
|
Yu JX, Bradt BM, Cooper NR. Constitutive expression of proinflammatory complement components by subsets of neurons in the central nervous system. J Neuroimmunol 2002; 123:91-101. [PMID: 11880154 DOI: 10.1016/s0165-5728(01)00483-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The brain is largely protected from damage due to infection, trauma, and aberrant processes by the innate immune system. These studies were undertaken to determine whether neurons in normal brains constitutively express complement components. In situ hybridization and immunohistochemical studies with specific riboprobes and antibodies, respectively, revealed that most hippocampal neurons, many pyramidal cortical neurons and cerebellar Purkinje neurons in normal murine brains constitutively express C3, C5 and C6. The constitutive expression by neuronal subsets of components of the complement activation and membrane attack pathways suggests that the complement system represents a "first line" of host defense in the brain.
Collapse
Affiliation(s)
- Jack X Yu
- Department of Immunology, The Scripps Research Institute, IMM-19, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | |
Collapse
|
38
|
O'Barr SA, Caguioa J, Gruol D, Perkins G, Ember JA, Hugli T, Cooper NR. Neuronal expression of a functional receptor for the C5a complement activation fragment. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:4154-62. [PMID: 11238666 DOI: 10.4049/jimmunol.166.6.4154] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The present studies were undertaken to determine whether neuronal subsets in normal brains constitutively express functionally competent C5a receptors. In situ hybridization studies coupled with immunohistochemical approaches revealed that most neurons in the hippocampal formation, many pyramidal cortical neurons, and cerebellar Purkinje neurons in normal human and murine brains constitutively express C5a receptors. Neuronal C5a receptors bound C5a-coated fluorescent microspheres, and primary rodent hippocampal neurons responded to C5a with increased calcium fluxes via a pertussis-sensitive, presumably Gi-coupled protein. Additional studies with human neuroblastoma cells conducted to address the functional role of C5a receptors revealed that C5a triggered rapid activation of protein kinase C and activation and nuclear translocation of the NF-kappa B transcription factor. In addition, C5a was found to be mitogenic for undifferentiated human neuroblastoma cells, a novel action for the C5aR. In contrast, C5a protected terminally differentiated human neuroblastoma cells from toxicity mediated by the amyloid A beta peptide. Thus, normal rodent hippocampal neurons as well as undifferentiated and differentiated human neuroblastoma cells express functional C5a receptors. These results have implications for understanding the role of neuronal C5aR receptors in normal neuronal development, neuronal homeostasis, and neuroinflammatory conditions such as Alzheimer's disease.
Collapse
MESH Headings
- Aged
- Amyloid beta-Peptides/toxicity
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/metabolism
- Antigens, CD/physiology
- Binding Sites/immunology
- Brain Chemistry/immunology
- Calcium/metabolism
- Cell Differentiation/immunology
- Cell Survival/immunology
- Complement C5a/metabolism
- Humans
- Immunohistochemistry
- Intracellular Fluid/immunology
- Intracellular Fluid/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Microscopy, Fluorescence
- Microspheres
- Nerve Growth Factors/physiology
- Neuroblastoma/immunology
- Neuroblastoma/metabolism
- Neuroblastoma/pathology
- Neurons/immunology
- Neurons/metabolism
- Neurons/physiology
- Peptide Fragments/biosynthesis
- Peptide Fragments/metabolism
- Peptide Fragments/physiology
- Receptor, Anaphylatoxin C5a
- Receptors, Complement/biosynthesis
- Receptors, Complement/metabolism
- Receptors, Complement/physiology
- Signal Transduction/immunology
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- S A O'Barr
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | | | | | | | | | |
Collapse
|
39
|
Eikelenboom P, Rozemuller AJ, Hoozemans JJ, Veerhuis R, van Gool WA. Neuroinflammation and Alzheimer disease: clinical and therapeutic implications. Alzheimer Dis Assoc Disord 2000; 14 Suppl 1:S54-61. [PMID: 10850731 DOI: 10.1097/00002093-200000001-00009] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In Alzheimer disease brains, the amyloid plaques are closely associated with a locally induced, nonimmune-mediated, chronic inflammatory response without any apparent influx of leukocytes from the blood. The present findings indicate that in cerebral A beta diseases (Alzheimer disease, Down syndrome, hereditary cerebral hemorrhage with amyloidosis-Dutch type), the clinical symptoms are determined to a great extent by the site of inflammatory response. It was found that the formation of the amyloid-microglia complex seems to be a relatively early pathogenic event that precedes the process of severe destruction of the neuropil. The idea that inflammation is implicated in Alzheimer pathology has received support from the epidemiologic studies indicating that the use of anti-inflammatory drugs can prevent or retard the Alzheimer disease process. In this contribution, we review the relationship between inflammation and clinical manifestation and the opportunities for anti-inflammatory treatments in Alzheimer disease.
Collapse
Affiliation(s)
- P Eikelenboom
- Research Institute Neurosciences Vrije Universiteit, Department of Psychiatry, Valeriuskliniek, Amsterdam, The Netherlands
| | | | | | | | | |
Collapse
|
40
|
Abstract
Apolipoprotein J (clusterin) is a ubiquitous multifunctional glycoprotein capable of interacting with a broad spectrum of molecules. In pathological conditions, it is an amyloid associated protein, co-localizing with fibrillar deposits in systemic and localized amyloid disorders. In Alzheimer's disease, the most frequent form of amyloidosis in humans and the major cause of dementia in the elderly, apoJ is present in amyloid plaques and cerebrovascular deposits but is rarely seen in NFT-containing neurons. ApoJ expression is up-regulated in a wide variety of insults and may represent a defense response against local damage to neurons. Four different mechanisms of action could be postulated to explain the role of apoJ as a neuroprotectant during cellular stress: (1) function as an anti-apoptotic signal, (2) protection against oxidative stress, (3) inhibition of the membrane attack complex of complement proteins locally activated as a result of inflammation, and (4) binding to hydrophobic regions of partially unfolded, stressed proteins, and therefore avoiding aggregation in a chaperone-like manner. This review focuses on the association of apoJ in biological fluids with Alzheimer's soluble Abeta. This interaction prevents Abeta aggregation and fibrillization and modulates its blood-brain barrier transport at the cerebrovascular endothelium.
Collapse
Affiliation(s)
- M Calero
- Department of Pathology, New York University School of Medicine, New York 10016, USA
| | | | | | | | | | | |
Collapse
|
41
|
Emmerling MR, Watson MD, Raby CA, Spiegel K. The role of complement in Alzheimer's disease pathology. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1502:158-71. [PMID: 10899441 DOI: 10.1016/s0925-4439(00)00042-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Complement proteins are integral components of amyloid plaques and cerebral vascular amyloid in Alzheimer brains. They can be found at the earliest stages of amyloid deposition and their activation coincides with the clinical expression of Alzheimer's dementia. This review will examine the origins of complement in the brain and the role of beta-amyloid peptide (Abeta) in complement activation in Alzheimer's disease, an event that might serve as a nidus of chronic inflammation. Pharmacology therapies that may serve to inhibit Abeta-mediated complement activation will also be discussed.
Collapse
Affiliation(s)
- M R Emmerling
- Neuroscience Therapeutics, Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, MI 48106, USA.
| | | | | | | |
Collapse
|
42
|
Schäfer MK, Schwaeble WJ, Post C, Salvati P, Calabresi M, Sim RB, Petry F, Loos M, Weihe E. Complement C1q is dramatically up-regulated in brain microglia in response to transient global cerebral ischemia. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:5446-52. [PMID: 10799911 DOI: 10.4049/jimmunol.164.10.5446] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recent evidence suggests that the pathophysiology of neurodegenerative and inflammatory neurological diseases has a neuroimmunological component involving complement, an innate humoral immune defense system. The present study demonstrates the effects of experimentally induced global ischemia on the biosynthesis of C1q, the recognition subcomponent of the classical complement activation pathway, in the CNS. Using semiquantitative in situ hybridization, immunohistochemistry, and confocal laser scanning microscopy, a dramatic and widespread increase of C1q biosynthesis in rat brain microglia (but not in astrocytes or neurons) within 24 h after the ischemic insult was observed. A marked increase of C1q functional activity in cerebrospinal fluid taken 1, 24, and 72 h after the ischemic insult was determined by C1q-dependent hemolytic assay. In the light of the well-established role of complement and complement activation products in the initiation and maintenance of inflammation, the ischemia-induced increase of cerebral C1q biosynthesis and of C1q functional activity in the cerebrospinal fluid implies that the proinflammatory activities of locally produced complement are likely to contribute to the pathophysiology of cerebral ischemia. Pharmacological modulation of complement activation in the brain may be a therapeutic target in the treatment of stroke.
Collapse
Affiliation(s)
- M K Schäfer
- Department of Anatomy, University of Marburg, Marburg, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Webster SD, Yang AJ, Margol L, Garzon-Rodriguez W, Glabe CG, Tenner AJ. Complement component C1q modulates the phagocytosis of Abeta by microglia. Exp Neurol 2000; 161:127-38. [PMID: 10683279 DOI: 10.1006/exnr.1999.7260] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies showing that microglia internalize the amyloid beta-peptide (Abeta) suggest that these cells have the potential for clearing Abeta deposits in Alzheimer's disease, and mechanisms that regulate the removal of Abeta may therefore be of clinical interest. Previous studies from this laboratory showing that C1q enhances phagocytosis of cellular targets by rat microglia prompted the current investigations characterizing the effects of C1q on microglial phagocytosis of Abeta. Microglia were shown to phagocytose Abeta1-42, in agreement with observations of other investigators. Uptake of Abeta1-42 was observed for concentrations of 5-50 microM, and phagocytosis of peptides containing (14)C or fluorescein (FM) labels was not affected by the interaction of microglia with C1q-coated surfaces. However, inclusion of C1q (125 nM-1.4 microM) in solutions of 50 microM Abeta1-42 inhibited the uptake of (14)C-Abeta1-42 and FM-Abeta1-42, suggesting that C1q blocks the interaction of Abeta with microglia. Uptake of Abeta was partially blocked by the scavenger receptor ligands polyinosinic acid and maleylated BSA. Inhibition of Abeta uptake by C1q may contribute to the accumulation of fibrillar, C1q-containing plaques that occurs in parallel with disease progression. These data suggest that mechanisms which interfere with the binding of C1q to Abeta may be of therapeutic value both through inhibition of the inflammatory events resulting from complement activation and via altered access of Abeta sites necessary for ingestion by microglia.
Collapse
Affiliation(s)
- S D Webster
- Department of Molecular Biology, University of California, Irvine, California, 92697, USA
| | | | | | | | | | | |
Collapse
|
44
|
Nataf S, Stahel PF, Davoust N, Barnum SR. Complement anaphylatoxin receptors on neurons: new tricks for old receptors? Trends Neurosci 1999; 22:397-402. [PMID: 10441300 DOI: 10.1016/s0166-2236(98)01390-3] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Activation of the complement system has been reported in a variety of inflammatory diseases and neurodegenerative processes of the CNS. Recent evidence indicates that complement proteins and receptors are synthesized on or by glial cells and, surprisingly, neurons. Among these proteins are the receptors for the chemotactic and anaphylactic peptides, C5a and C3a, which are the most-potent mediators of complement inflammatory functions. The functions of glial-cell C3a and C5a receptors (C3aR and C5aR) appear to be similar to immune-cell C3aRs and C5aRs. However, little is known about the roles these receptors might have on neurons. Indeed, when compared with glial cells, neurons display a distinct pattern of C3aR and C5aR expression, in either the normal or the inflamed CNS. These findings suggest unique functions for these receptors on neurons.
Collapse
Affiliation(s)
- S Nataf
- Dept of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294-0005, USA
| | | | | | | |
Collapse
|
45
|
Grewal RP, Morgan TE, Finch CE. C1qB and clusterin mRNA increase in association with neurodegeneration in sporadic amyotrophic lateral sclerosis. Neurosci Lett 1999; 271:65-7. [PMID: 10471215 DOI: 10.1016/s0304-3940(99)00496-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We analyzed postmortem tissues of sporadic amyotrophic lateral sclerosis (SALS) for mRNA levels of two inflammatory proteins, complement C1qB and clusterin (apoJ). By Northern blot hybridization, SALS was associated with increased mRNA for C1qB and clusterin in the motor cortex (Brodmann area A4), but not in superior temporal cortex (A17), relative to neurologically normal controls. By in situ hybridization, SALS spinal cords showed increased C1qB and clusterin mRNA in areas undergoing neurodegeneration. This evidence implicates inflammatory mechanisms during neurodegenerative processes in SALS.
Collapse
Affiliation(s)
- R P Grewal
- Department of Neurology, School of Medicine, University of Southern California, Los Angeles 90089-1340, USA.
| | | | | |
Collapse
|
46
|
Wing MG, Seilly DJ, Nicholas RS, Rahman S, Zajicek J, Lachmann PJ, Compston DA. Comparison of C1q-receptors on rat microglia and peritoneal macrophages. J Neuroimmunol 1999; 94:74-81. [PMID: 10376938 DOI: 10.1016/s0165-5728(98)00227-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A comparison of the expression and ligand specificity of the C1q (first complement component) receptor on rat microglia and peritoneal macrophages was made. This revealed that radiolabelled C1q was competed from the peritoneal macrophages with intact C1q, and additively displaced by calf-skin collagen and purified C1q globular heads, suggesting the presence of at least two receptors. This was in contrast to microglia, where radiolabelled C1q was displaced with intact C1q and to a modest degree with collagen, but not with globular heads. Taken together, this implies that under these conditions, peritoneal macrophages and microglia both express a C1q receptor which binds to the collagen-like region, and that peritoneal macrophages additionally express a molecule which binds to the globular head of C1q. Analysis of the ligand bound by these cells reflected the differences observed in the competitive binding experiments, with the novel identification of naturally-occurring peptides from the globular head of C1q bound to the peritoneal macrophages, but not the microglia.
Collapse
Affiliation(s)
- M G Wing
- Molecular Immunopathology Unit, MRC Centre, Cambridge, UK.
| | | | | | | | | | | | | |
Collapse
|
47
|
Bulinski JC, Ohm T, Roder H, Spruston N, Turner DA, Wheal HV. Changes in dendritic structure and function following hippocampal lesions: correlations with developmental events? Prog Neurobiol 1998; 55:641-50. [PMID: 9670222 DOI: 10.1016/s0301-0082(98)00023-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recovery after nervous system lesions may lead to partial re-institution of developmental schemes and processes. Here we review several of these proposed schemes, with the conclusion that though some processes may involve re-expression of embryonic phenotypes, there are many processes invoked during recovery from lesions that do not mirror developmental phenomena. The inability to fully revert to embryonic schemes because of adult phenotype may partially account for the decreased recovery observed in adults compared to that noted after lesions during development.
Collapse
Affiliation(s)
- J C Bulinski
- Department of Anatomy & Cell Biology, Columbia University, College of Physicians & Surgeons, New York, NY 10032-3702, USA.
| | | | | | | | | | | |
Collapse
|
48
|
Page KJ, Hollister RD, Hyman BT. Dissociation of apolipoprotein and apolipoprotein receptor response to lesion in the rat brain: an in situ hybridization study. Neuroscience 1998; 85:1161-71. [PMID: 9681954 DOI: 10.1016/s0306-4522(97)00661-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The epsilon4 allele of apolipoprotein E is associated with increased risk for developing Alzheimer's disease. To further understand the anatomical distribution of apolipoprotein E and its native receptors in the brain, we studied their messenger RNA expression in the adult rat brain under normal conditions and in response to an excitotoxic lesion to the hippocampus. In situ hybridization using oligonucleotide probes for apolipoprotein E, apolipoprotein J, the low density lipoprotein receptor, very low density lipoprotein receptor, low density lipoprotein receptor related protein, 39,000 mol. wt receptor-associated protein and glycoprotein 330/Megalin messenger RNA were performed on adjacent sections throughout the rat forebrain. Apolipoprotein E messenger RNA was abundantly expressed in the rat brain in both white and gray matter localizing to astrocytes but not neurons. Low density lipoprotein receptor-related protein and receptor-associated protein messenger RNA had a similar regional distribution but low density lipoprotein receptor-related protein messenger RNA was expressed by both neurons and glia, while the expression of receptor-associated protein messenger RNA was more highly expressed in neurons. Apolipoprotein J messenger RNA was expressed by neurons, glia and choroid plexus. The low density lipoprotein receptor and very low density lipoprotein receptor messenger RNA were found in both neurons and glia. Glycoprotein 330/Megalin messenger RNA was not detectable in the adult rat brain. In response to hippocampal lesions, apolipoprotein E and apolipoprotein J messenger RNAs were significantly up-regulated seven and 11 days post-lesion but the expression of low density lipoprotein receptor, low density lipoprotein receptor-related protein, receptor-associated protein, glycoprotein 330/Megalin, and very low density lipoprotein receptor messenger RNAs were unchanged. The expression of apolipoprotein E messenger RNA increased gradually beginning at three days while the expression of apolipoprotein J messenger RNA began to increase at seven days post-lesion. These findings further implicate apolipoproteins in the response of the brain to injury in vivo and suggest that transcriptional up-regulation of the apolipoprotein receptors studied is not a prominent feature in the response.
Collapse
Affiliation(s)
- K J Page
- Neurology Service, Massachusetts General Hospital, and Harvard Medical School, Boston, USA
| | | | | |
Collapse
|
49
|
Stahel PF, Morganti-Kossmann MC, Kossmann T. The role of the complement system in traumatic brain injury. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 1998; 27:243-56. [PMID: 9729408 DOI: 10.1016/s0165-0173(98)00015-0] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A traumatic impact to the brain induces an intracranial inflammatory response, which consequently leads to the development of brain edema and delayed neuronal death. Evidence from experimental, clinical, and in vitro studies highlight an important role for the complement system in contributing to inflammation within the injured brain. The present review summarizes the current understanding of the mechanisms of complement-mediated secondary brain injury after head trauma.
Collapse
Affiliation(s)
- P F Stahel
- Division of Trauma Surgery, Department of Surgery, University Hospital, CH-8091 Zürich, Switzerland.
| | | | | |
Collapse
|
50
|
Walker DG. Expression and regulation of complement C1q by human THP-1-derived macrophages. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1998; 34:197-218. [PMID: 10327418 DOI: 10.1007/bf02815080] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The regulation of C1q expression was examined in the human monocytic cell line THP-1. Since these cells can be differentiated into cells with macrophage properties and induced to express C1q, they were used as models for mature human monocyte/macrophages and indirectly microglia. Interferon-gamma (IFN-gamma) and the anti-inflammatory steroid agents dexamethasone and prednisone were powerful stimulators of C1q production, alone or in combination. Interleukin-6 (IL-6) and lipopolysaccharide (LPS) also had significant stimulatory activity. Phorbol myristate acetate, a protein kinase C activator, reduced C1q expression. Four additional classes of pharmacological agents were tested for their effect on C1q secretion. Tacrine, but not indomethacin, cimetidine, or propentofylline, showed activity in inhibiting C1q secretion by IFN-gamma treated THP-1-derived macrophages.
Collapse
Affiliation(s)
- D G Walker
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, University of British Columbia, Vancouver, Canada.
| |
Collapse
|