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Nimmo J, Byrne R, Daskoulidou N, Watkins L, Carpanini S, Zelek W, Morgan B. The complement system in neurodegenerative diseases. Clin Sci (Lond) 2024; 138:387-412. [PMID: 38505993 PMCID: PMC10958133 DOI: 10.1042/cs20230513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/15/2024] [Accepted: 03/01/2024] [Indexed: 03/21/2024]
Abstract
Complement is an important component of innate immune defence against pathogens and crucial for efficient immune complex disposal. These core protective activities are dependent in large part on properly regulated complement-mediated inflammation. Dysregulated complement activation, often driven by persistence of activating triggers, is a cause of pathological inflammation in numerous diseases, including neurological diseases. Increasingly, this has become apparent not only in well-recognized neuroinflammatory diseases like multiple sclerosis but also in neurodegenerative and neuropsychiatric diseases where inflammation was previously either ignored or dismissed as a secondary event. There is now a large and rapidly growing body of evidence implicating complement in neurological diseases that cannot be comprehensively addressed in a brief review. Here, we will focus on neurodegenerative diseases, including not only the 'classical' neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, but also two other neurological diseases where neurodegeneration is a neglected feature and complement is implicated, namely, schizophrenia, a neurodevelopmental disorder with many mechanistic features of neurodegeneration, and multiple sclerosis, a demyelinating disorder where neurodegeneration is a major cause of progressive decline. We will discuss the evidence implicating complement as a driver of pathology in these diverse diseases and address briefly the potential and pitfalls of anti-complement drug therapy for neurodegenerative diseases.
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Affiliation(s)
- Jacqui Nimmo
- UK Dementia Research Institute Cardiff, Cardiff University, Cardiff CF24 4HQ, U.K
| | - Robert A.J. Byrne
- UK Dementia Research Institute Cardiff, Cardiff University, Cardiff CF24 4HQ, U.K
| | - Nikoleta Daskoulidou
- UK Dementia Research Institute Cardiff, Cardiff University, Cardiff CF24 4HQ, U.K
| | - Lewis M. Watkins
- UK Dementia Research Institute Cardiff, Cardiff University, Cardiff CF24 4HQ, U.K
| | - Sarah M. Carpanini
- UK Dementia Research Institute Cardiff, Cardiff University, Cardiff CF24 4HQ, U.K
| | - Wioleta M. Zelek
- UK Dementia Research Institute Cardiff, Cardiff University, Cardiff CF24 4HQ, U.K
| | - B. Paul Morgan
- UK Dementia Research Institute Cardiff, Cardiff University, Cardiff CF24 4HQ, U.K
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2
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Fatoba O, Itokazu T, Yamashita T. Complement cascade functions during brain development and neurodegeneration. FEBS J 2021; 289:2085-2109. [PMID: 33599083 DOI: 10.1111/febs.15772] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 02/07/2021] [Accepted: 02/16/2021] [Indexed: 12/12/2022]
Abstract
The complement system, an essential tightly regulated innate immune system, is a key regulator of normal central nervous system (CNS) development and function. However, aberrant complement component expression and activation in the brain may culminate into marked neuroinflammatory response, neurodegenerative processes and cognitive impairment. Over the years, complement-mediated neuroinflammatory responses and complement-driven neurodegeneration have been increasingly implicated in the pathogenesis of a wide spectrum of CNS disorders. This review describes how complement system contributes to normal brain development and function. We also discuss how pathologic insults such as misfolded proteins, lipid droplet/lipid droplet-associated protein or glycosaminoglycan accumulation could trigger complement-mediated neuroinflammatory responses and neurodegenerative process in neurodegenerative proteinopathies, age-related macular degeneration and neurodegenerative lysosomal storage disorders.
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Affiliation(s)
- Oluwaseun Fatoba
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan.,WPI-Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Takahide Itokazu
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan.,WPI-Immunology Frontier Research Center, Osaka University, Suita, Japan.,Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Japan
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3
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Brennan FH, Lee JD, Ruitenberg MJ, Woodruff TM. Therapeutic targeting of complement to modify disease course and improve outcomes in neurological conditions. Semin Immunol 2016; 28:292-308. [PMID: 27049459 DOI: 10.1016/j.smim.2016.03.015] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/17/2016] [Accepted: 03/18/2016] [Indexed: 12/14/2022]
Abstract
The recognition that complement proteins are abundantly present and can have pathological roles in neurological conditions offers broad scope for therapeutic intervention. Accordingly, an increasing number of experimental investigations have explored the potential of harnessing the unique activation pathways, proteases, receptors, complexes, and natural inhibitors of complement, to mitigate pathology in acute neurotrauma and chronic neurodegenerative diseases. Here, we review mechanisms of complement activation in the central nervous system (CNS), and explore the effects of complement inhibition in cerebral ischemic-reperfusion injury, traumatic brain injury, spinal cord injury, Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease and Huntington's disease. We consider the challenges and opportunities arising from these studies. As complement therapies approach clinical translation, we provide perspectives on how promising complement-targeted therapeutics could become part of novel and effective future treatment options to improve outcomes in the initiation and progression stages of these debilitating CNS disorders.
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Affiliation(s)
- Faith H Brennan
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia
| | - John D Lee
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia
| | - Marc J Ruitenberg
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia; Trauma, Critical Care and Recovery, Brisbane Diamantina Health Partners, The University of Queensland, Brisbane 4072, Australia
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia.
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4
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Ratelade J, Zhang H, Saadoun S, Bennett JL, Papadopoulos MC, Verkman AS. Neuromyelitis optica IgG and natural killer cells produce NMO lesions in mice without myelin loss. Acta Neuropathol 2012; 123:861-72. [PMID: 22526022 DOI: 10.1007/s00401-012-0986-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 04/10/2012] [Accepted: 04/11/2012] [Indexed: 01/05/2023]
Abstract
The pathogenesis of neuromyelitis optica (NMO) involves targeting of NMO-immunoglobulin G (NMO-IgG) to aquaporin-4 (AQP4) on astrocytes in the central nervous system. Prior work provided evidence for complement-dependent cytotoxicity (CDC) in NMO lesion development. Here, we show that antibody-dependent cellular cytotoxicity (ADCC), in the absence of complement, can also produce NMO-like lesions. Antibody-dependent cellular cytotoxicity was produced in vitro by incubation of mouse astrocyte cultures with human recombinant monoclonal NMO-IgG and human natural killer cells (NK-cells). Injection of NMO-IgG and NK-cells in mouse brain caused loss of AQP4 and GFAP, two characteristic features of NMO lesions, but little myelin loss. Lesions were minimal or absent following injection of: (1) control (non-NMO) IgG with NK-cells; (2) NMO-IgG and NK-cells in AQP4-deficient mice; or (3) NMO-IgG and NK-cells in wild-type mice together with an excess of mutated NMO-IgG lacking ADCC effector function. NK-cells greatly exacerbated NMO lesions produced by NMO-IgG and complement in an ex vivo spinal cord slice model of NMO, causing marked myelin loss. NMO-IgG can thus produce astrocyte injury by ADCC in a complement-independent and dependent manner, suggesting the potential involvement of ADCC in NMO pathogenesis.
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Affiliation(s)
- Julien Ratelade
- Department of Medicine, University of California, San Francisco, 1246 Health Sciences East Tower, San Francisco, CA 94143-0521, USA
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5
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Griffiths MR, Gasque P, Neal JW. The regulation of the CNS innate immune response is vital for the restoration of tissue homeostasis (repair) after acute brain injury: a brief review. Int J Inflam 2010; 2010:151097. [PMID: 21152121 PMCID: PMC2989866 DOI: 10.4061/2010/151097] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 01/06/2010] [Accepted: 04/28/2010] [Indexed: 12/12/2022] Open
Abstract
Neurons and glia respond to acute injury by participating in the CNS innate immune response. This involves the recognition and clearance of "not self " pathogens and "altered self " apoptotic cells. Phagocytic receptors (CD14, CD36, TLR-4) clear "not self" pathogens; neurons and glia express "death signals" to initiate apoptosis in T cells.The complement opsonins C1q, C3, and iC3b facilitate the clearance of apoptotic cells by interacting with CR3 and CR4 receptors. Apoptotic cells are also cleared by the scavenger receptors CD14, Prs-R, TREM expressed by glia. Serpins also expressed by glia counter the neurotoxic effects of thrombin and other systemic proteins that gain entry to the CNS following injury. Complement pathway and T cell activation are both regulated by complement regulatory proteins expressed by glia and neurons. CD200 and CD47 are NIRegs expressed by neurons as "don't eat me" signals and they inhibit microglial activity preventing host cell attack. Neural stem cells regulate T cell activation, increase the Treg population, and suppress proinflammatory cytokine expression. Stem cells also interact with the chemoattractants C3a, C5a, SDF-1, and thrombin to promote stem cell migration into damaged tissue to support tissue homeostasis.
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Affiliation(s)
- M. R. Griffiths
- Deptartment of Medical Biochemistry, University Hospital of Wales, Cardiff University Medical School, Cardiff CF14 4XN, UK
| | - P. Gasque
- Deptartment of Medical Biochemistry, University Hospital of Wales, Cardiff University Medical School, Cardiff CF14 4XN, UK
- University Labo. Biochimie et Genetique Moleculaire, Facilities de Science et Technologies, Universite de La Reunion, 15 Avenue Rene Cassin Saint Denis, Ile de la Reunion, BP 7151, 97715, France
| | - J. W. Neal
- Deptartment of Histopathology, University Hospital of Wales, Cardiff University Medical School, Cardiff CF14 4XN, UK
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6
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Abstract
The complement (C) system plays a central role in innate immunity and bridges innate and adaptive immune responses. A fine balance of C activation and regulation mediates the elimination of invading pathogens and the protection of the host from excessive C deposition on healthy tissues. If this delicate balance is disrupted, the C system may cause injury and contribute to the pathogenesis of various diseases, including neurodegenerative disorders and neuropathies. Here we review evidence indicating that C factors and regulators are locally synthesized in the nervous system and we discuss the evidence supporting the protective or detrimental role of C activation in health, injury, and disease of the nerve.
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Affiliation(s)
- V Ramaglia
- Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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7
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Woodruff TM, Ager RR, Tenner AJ, Noakes PG, Taylor SM. The role of the complement system and the activation fragment C5a in the central nervous system. Neuromolecular Med 2009; 12:179-92. [PMID: 19763906 DOI: 10.1007/s12017-009-8085-y] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 08/25/2009] [Indexed: 12/28/2022]
Abstract
The complement system is a pivotal component of the innate immune system which protects the host from infection and injury. Complement proteins can be induced in all cell types within the central nervous system (CNS), where the pathway seems to play similar roles in host defense. Complement activation produces the C5 cleavage fragment C5a, a potent inflammatory mediator, which recruits and activates immune cells. The primary cellular receptor for C5a, the C5a receptor (CD88), has been reported to be on all CNS cells, including neurons and glia, suggesting a functional role for C5a in the CNS. A second receptor for C5a, the C5a-like receptor 2 (C5L2), is also expressed on these cells; however, little is currently known about its potential role in the CNS. The potent immune and inflammatory actions of complement activation are necessary for host defense. However, if over-activated, or left unchecked it promotes tissue injury and contributes to brain disease pathology. Thus, complement activation, and subsequent C5a generation, is thought to play a significant role in the progression of CNS disease. Paradoxically, complement may also exert a neuroprotective role in these diseases by aiding in the elimination of aggregated and toxic proteins and debris which are a principal hallmark of many of these diseases. This review will discuss the expression and known roles for complement in the CNS, with a particular focus on the pro-inflammatory end-product, C5a. The possible overarching role for C5a in diseases of the CNS is reviewed, and the therapeutic potential of blocking C5a/CD88 interaction is evaluated.
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Affiliation(s)
- Trent M Woodruff
- School of Biomedical Sciences, University of Queensland, St. Lucia, Brisbane, 4072, Australia.
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8
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Hinson SR, McKeon A, Lennon VA. Neurological autoimmunity targeting aquaporin-4. Neuroscience 2009; 168:1009-18. [PMID: 19699271 DOI: 10.1016/j.neuroscience.2009.08.032] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 08/06/2009] [Accepted: 08/12/2009] [Indexed: 10/20/2022]
Abstract
Neuromyelitis optica (NMO) is the first inflammatory autoimmune demyelinating disease of the CNS for which a specific tissue target molecule has been identified--the astrocytic water channel aquaporin-4 (AQP4). Immunological insights have propelled significant advances in understanding the clinical, radiologic and immunopathologic characteristics of the disease in the last 5 years. In this review, we describe features distinguishing CNS AQP4 autoimmunity from classical multiple sclerosis (MS). In NMO, disease attacks preferentially involve the optic nerves and spinal cord (hence the name), but neurological signs in the initial attack of AQP4 autoimmunity in children commonly involve the brain. A clinically validated serum biomarker, NMO-IgG, distinguishes relapsing CNS inflammatory demyelinating disorders related to NMO from MS. The NMO-IgG autoantibody is AQP4-specific. Clinical, radiological and immunopathological data support its role in the pathogenesis of NMO spectrum disorders. Lesions characteristic of NMO are distinct from MS: AQP4 and its coupled glutamate transporter, excitatory amino acid transporter 2 (EAAT2), are lost, with and without associated myelin loss, IgG, IgM and complement are deposited in a vasculocentric pattern, edema and inflammation are prominent. In vitro studies demonstrate that binding of NMO-IgG to astrocytic AQP4 initiates multiple potentially neuropathogenic mechanisms: complement activation, AQP4 and EAAT2 downregulation with disruption of water and glutamate homeostasis, enhanced blood-brain barrier permeability, plasma protein and granulocyte influx, and antibody-dependent cell-mediated cytotoxicity. Development of effective, and potentially curative, therapies requires validated models of the disease, in animals and cell culture systems.
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Affiliation(s)
- S R Hinson
- Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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9
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Hellrung DJ, Kisselev S, Link CJ. Co-expression of alpha(1,3)galactosyltransferase and Bacillus thuringiensis PIPLC enhances hyperacute rejection of tumor cells. Cancer Immunol Immunother 2007; 56:25-34. [PMID: 16612594 PMCID: PMC11030725 DOI: 10.1007/s00262-006-0163-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2006] [Accepted: 03/15/2006] [Indexed: 11/29/2022]
Abstract
The use of alpha(1,3)galactosyltransferase (alphaGT) as a method of inducing hyperacute rejection of tumors has been gaining interest recently. However, the approach is based in part on the sensitivity of each tumor line to the effects of complement lysis. Tumors expressing complement resistance factors such as membrane cofactor (CD46), decay accelerating factor (CD55) and protectin (CD59) have been shown to be more resistant to complement mediated lysis. Anchored to the membrane by a glycosylphosphoinositol moiety (GPI-anchored), CD55 and CD59 can be cleaved by Bacillus thuringiensis phosphatidylinositol-specific phospholipase C (PIPLC). Complement resistant A549 human lung carcinoma cells were engineered to express both the murine alphaGT gene and the B. thuringiensis PIPLC gene to alleviate complement resistance and enhance alphagal-mediated cancer killing. The PIPLC native signal sequence was replaced with the human epidermal growth factor signal sequence, EGFssPIPLC, to induce secretion from A549. Expression of EGFssPIPLC resulted in complete removal of CD55 and CD59 while sparing the non-GPI-anchored CD46. Results demonstrated that A549 cells transduced with two recombinant retroviral vectors carrying the alphaGT and EGFssPIPLC genes expressed high levels of alphagal epitope and exhibited a 5-fold increase in sensitivity to anti-alphagal mediated complement lysis.
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Affiliation(s)
- Daniel J. Hellrung
- Iowa Cancer Research Foundation, 11043 Aurora Avenue, Urbandale, IA 50322 USA
- Iowa State University, Ames, IA USA
| | - Serguei Kisselev
- Iowa Cancer Research Foundation, 11043 Aurora Avenue, Urbandale, IA 50322 USA
| | - Charles J. Link
- Iowa Cancer Research Foundation, 11043 Aurora Avenue, Urbandale, IA 50322 USA
- Iowa State University, Ames, IA USA
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10
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Hosokawa M, Klegeris A, McGeer PL. Human oligodendroglial cells express low levels of C1 inhibitor and membrane cofactor protein mRNAs. J Neuroinflammation 2004; 1:17. [PMID: 15327690 PMCID: PMC516791 DOI: 10.1186/1742-2094-1-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Accepted: 08/24/2004] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND: Oligodendrocytes, neurons, astrocytes, microglia, and endothelial cells are capable of synthesizing complement inhibitor proteins. Oligodendrocytes are vulnerable to complement attack, which is particularly observed in multiple sclerosis. This vulnerability may be related to a deficiency in their ability to express complement regulatory proteins. METHODS: This study compared the expression level of complement inhibitor mRNAs by human oligodendrocytes, astrocytes and microglia using semi-quantitative RT-PCR. RESULTS: Semi-quantitative RT-PCR analysis showed that C1 inhibitor (C1-inh) mRNA expression was dramatically lower in oligodendroglial cells compared with astrocytes and microglia. The mRNA expression level of membrane cofactor protein (MCP) by oligodendrocytes was also significantly lower than for other cell types. CONCLUSION: The lower mRNA expression of C1-inh and MCP by oligodendrocytes could contribute to their vulnerability in several neurodegenerative and inflammatory diseases of the central nervous system.
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Affiliation(s)
- Masato Hosokawa
- Kinsmen Laboratory of Neurological Research, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Andis Klegeris
- Kinsmen Laboratory of Neurological Research, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Patrick L McGeer
- Kinsmen Laboratory of Neurological Research, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
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11
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Soane L, Cho HJ, Niculescu F, Rus H, Shin ML. C5b-9 terminal complement complex protects oligodendrocytes from death by regulating Bad through phosphatidylinositol 3-kinase/Akt pathway. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:2305-11. [PMID: 11490019 DOI: 10.4049/jimmunol.167.4.2305] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Apoptosis of oligodendrocytes is induced by serum growth factor deprivation. We showed that oligodendrocytes and progenitor cells respond to serum withdrawal by a rapid decline of Bcl-2 mRNA expression and caspase-3-dependent apoptotic death. Sublytic assembly of membrane-inserted terminal complement complexes consisting of C5b, C6, C7, C8, and C9 proteins (C5b-9) inhibits caspase-3 activation and apoptotic death of oligodendrocytes. In this study, we examined an involvement of the mitochondria in oligodendrocyte apoptosis and the role of C5b-9 on this process. Decreased phosphatidylinositol 3-kinase and Akt activities occurred in association with cytochrome c release and caspase-9 activation when cells were placed in defined medium. C5b-9 inhibited the mitochondrial pathway of apoptosis in oligodendrocytes, as shown by decreased cytochrome c release and inhibition of caspase-9 activation. Phosphatidylinositol 3-phosphate kinase and Akt activities were also induced by C5b-9, and the phosphatidylinositol 3-phosphate kinase inhibitor LY294002 reversed the protective effect of C5b-9. Phosphatidylinositol 3-phosphate kinase activity was also responsible for the phosphorylation of Bad at Ser112 and Ser136. This phosphorylation resulted in dissociation of Bad from the Bad/Bcl-xL complex in a G(i)alpha-dependent manner. The mitochondrial pathway of oligodendrocyte apoptosis is, therefore, inhibited by C5b-9 through post-translational regulation of Bad. This mechanism may be involved in the promotion of oligodendrocyte survival in inflammatory demyelinating disorders affecting the CNS.
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Affiliation(s)
- L Soane
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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12
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Tang H, Brimijoin S. Complement regulatory proteins and selective vulnerability of neurons to lysis on exposure to acetylcholinesterase antibody. J Neuroimmunol 2001; 115:53-63. [PMID: 11282154 DOI: 10.1016/s0165-5728(01)00249-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Systemic injection of antibodies against acetylcholinesterase (AChE) induces complement-mediated destruction of preganglionic nerve terminals in paravertebral sympathetic ganglia, but spares other AChE-rich structures, such as nerve terminals in prevertebral sympathetic ganglia, parasympathetic ganglia, and the neuromuscular junction. This pattern of differing sensitivity to "AChE immunolesion" might be explained by a differing expression of proteins that serve to protect host cells from complement activation. Two major complement regulatory proteins in rats are Crry, which interferes with the assembly of C3 convertase, and CD59, which blocks formation of the terminal cytolytic membrane attack complex. The present study used immunohistochemistry to demonstrate an inverse relation between levels of CD59 and Crry expression and sensitivity to AChE immunolesion in several AChE-rich targets. Thus, the most sensitive structures, i.e., preganglionic nerve terminals in the adrenal gland and superior cervical ganglion (SCG), expressed undetectable levels of CD59 and Crry immunoreactivities. By contrast, AChE-rich, but antibody-resistant, cholinergic nerve terminals in the inferior mesenteric ganglia (IMG) and diaphragm muscle expressed significant amounts of CD59 and Crry. Such expression was functionally important because, after membrane-anchored CD59 was removed from explanted IMG with phosphatidylinositol phospholipase C, exposure to AChE antibody and complement caused greater immunolesion. It was concluded that differential expression of regulatory proteins in different parts of the nervous system influences regional vulnerability to complement mediated damage.
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MESH Headings
- Acetylcholinesterase/immunology
- Adrenal Glands/innervation
- Animals
- Antibodies/pharmacology
- Antigens, Surface
- CD59 Antigens/metabolism
- Complement System Proteins/metabolism
- Diaphragm/metabolism
- Ganglia, Parasympathetic/drug effects
- Ganglia, Parasympathetic/metabolism
- Ganglia, Parasympathetic/pathology
- Ganglia, Sympathetic/drug effects
- Ganglia, Sympathetic/immunology
- Ganglia, Sympathetic/pathology
- Immunohistochemistry
- In Vitro Techniques
- Male
- Neurons/drug effects
- Neurons/immunology
- Neurons/pathology
- Organ Specificity/drug effects
- Organ Specificity/immunology
- Phosphatidylinositol Diacylglycerol-Lyase
- Presynaptic Terminals/drug effects
- Presynaptic Terminals/immunology
- Presynaptic Terminals/pathology
- Rats
- Rats, Sprague-Dawley
- Receptors, Cell Surface
- Receptors, Complement/metabolism
- Spinal Cord/cytology
- Spinal Cord/metabolism
- Superior Cervical Ganglion/drug effects
- Superior Cervical Ganglion/immunology
- Superior Cervical Ganglion/pathology
- Sympathectomy, Chemical
- Type C Phospholipases/metabolism
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Affiliation(s)
- H Tang
- Department of Pharmacology, Mayo Clinic, 727 Guggenheim Building, Rochester, MN 55905, USA.
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13
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Gasque P, Dean YD, McGreal EP, VanBeek J, Morgan BP. Complement components of the innate immune system in health and disease in the CNS. IMMUNOPHARMACOLOGY 2000; 49:171-86. [PMID: 10904116 DOI: 10.1016/s0162-3109(00)80302-1] [Citation(s) in RCA: 253] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The innate immune system and notably the complement (C) system play important roles in host defense to recognise and kill deleterious invaders or toxic entities, but activation at inappropriate sites or to an excessive degree can cause severe tissue damage. C has been implicated as a factor in the exacerbation and propagation of tissue injury in numerous diseases including neurodegenerative disorders. In this article, we review the evidence indicating that brain cells can synthesise a full lytic C system and also express specific C inhibitors (to protect from C activation and C lysis) and C receptors (involved in cell activation, chemotaxis and phagocytosis). We also summarise the mechanisms involved in the antibody-independent activation of the classical pathway of C in Alzheimer's disease, Huntington's disease and Pick's disease. Although the primary role of C activation on a target cell is to induce cell lysis (particularly of neurons), we present evidence indicating that C (C3a, C5a, sublytic level of C5b-9) may also be involved in pro- as well as anti-inflammatory activities. Moreover, we discuss evidence suggesting that local C activation may contribute to tissue remodelling activities during repair in the CNS.
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Affiliation(s)
- P Gasque
- Department of Medical Biochemistry, University of Wales College of Medicine, Cardiff, UK.
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14
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Spiller OB, Criado-García O, Rodríguez De Córdoba S, Morgan BP. Cytokine-mediated up-regulation of CD55 and CD59 protects human hepatoma cells from complement attack. Clin Exp Immunol 2000; 121:234-41. [PMID: 10931136 PMCID: PMC1905706 DOI: 10.1046/j.1365-2249.2000.01305.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatic parenchymal cells respond in many different ways to acute-phase cytokines. Some responses may protect against damage by liver-derived inflammatory mediators. Previous investigations have shown that cytokines cause increased secretion by hepatoma cells of soluble complement regulatory proteins, perhaps providing protection from complement attack. More important to cell protection are the membrane complement regulators. Here we examine, using flow cytometry and Northern blotting, the effects of different cytokines, singly or in combination, on expression of membrane-bound complement regulators by a hepatoma cell line. The combination of tumour necrosis factor-alpha, IL-1beta, and IL-6 caused increased expression of CD55 (three-fold) and CD59 (two-fold) and decreased expression of CD46 at day 3 post-exposure. Interferon-gamma reduced expression of CD59 and strongly antagonized the up-regulatory effects on CD59 mediated by the other cytokines. Complement attack on antibody-sensitized hepatoma cells following a 3-day incubation with the optimum combination of acute-phase cytokines revealed increased resistance to complement-mediated lysis and decreased C3b deposition. During the acute-phase response there is an increased hepatic synthesis of the majority of complement effector proteins. Simultaneous up-regulation of expression of CD55 and CD59 may serve to protect hepatocytes from high local concentrations of complement generated during the acute-phase response.
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MESH Headings
- Acute-Phase Reaction/genetics
- Acute-Phase Reaction/immunology
- Antigens, Neoplasm/biosynthesis
- Antigens, Neoplasm/genetics
- CD55 Antigens/biosynthesis
- CD55 Antigens/genetics
- CD59 Antigens/biosynthesis
- CD59 Antigens/genetics
- Carcinoma, Hepatocellular/immunology
- Carcinoma, Hepatocellular/microbiology
- Carcinoma, Hepatocellular/pathology
- Complement Membrane Attack Complex/antagonists & inhibitors
- Complement System Proteins/immunology
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Interleukin-1/pharmacology
- Interleukin-6/pharmacology
- Liver Neoplasms/immunology
- Liver Neoplasms/metabolism
- Liver Neoplasms/pathology
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/immunology
- Tumor Necrosis Factor-alpha/pharmacology
- Up-Regulation/drug effects
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Affiliation(s)
- O B Spiller
- Complement Biology Group, Department of Medical Biochemistry, University of Wales College of Medicine, Cardiff, UK.
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15
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Abstract
The expression of the murine complement regulatory protein, Crry, in the CNS remains largely unexplored. In this study, we examined murine astrocytes and microglia purified from neonatal brain and sections of adult murine brain for the expression of Crry. Using RT-PCR, immunohistochemistry, in situ hybridization, flow cytometry, and Western blot analysis, we demonstrated that astrocytes and microglia express Crry protein and RNA. Crry expression is greater on microglia than astrocytes and, as determined by Western blot analysis, each cell type expresses a Crry protein of different molecular weight. Interestingly, neuronal expression of Crry was seen only at the RNA level. These data demonstrate Crry expression by astrocytes, microglia, and neurons in the murine CNS and suggest that Crry may play an important role in protecting the CNS against complement-mediated damage.
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Affiliation(s)
- N Davoust
- Department of Microbiology and the Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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16
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Sayah S, Patte C, Gasque P, Chan P, Ischenko A, Vaudry H, Fontaine M. Characterization of rat C5a anaphylatoxin receptor (C5aR): cloning of rat C5aR cDNA and study of C5aR expression by rat astrocytes. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1997; 48:215-22. [PMID: 9332718 DOI: 10.1016/s0169-328x(97)00094-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Complement system activation within the central nervous system (CNS) is involved in demyelinating and neurodegenerative disorders, but the role of complement in the pathogenic process or in the repair remains unclear. Besides the direct lytic effects of complement on target cells (oligodendrocytes or neurons), complement can exert other functions through interaction of complement fragments with specific receptors. The C5a anaphylatoxin, an inflammatory peptide which is formed during complement activation, might play a role in the CNS pathogenesis, and activation and recruitment of glial cells by binding to its receptor (C5aR) on CNS cells. Using degenerate primers corresponding to homologous regions between human and mouse C5aR cDNAs, we have cloned a rat C5aR cDNA probe from rat monocytes RNAs after RT-PCR experiment. The rat C5aR probe isolated by this procedure allowed us to clone the rat C5aR cDNA-coding sequence using a library screening cloning strategy. This probe was also used to study the expression of the C5aR mRNA in the rat CNS. Northern blotting and RT-PCR experiments demonstrated the constitutive expression of C5aR mRNA in brain, spleen, kidney and lung. This transcript was also observed in primary culture of rat astrocytes. Microfluorimetry experiments demonstrated that C5aR expressed by astrocytes in culture is functional since the addition of C5a induced a dose-dependent increase of intracellular calcium concentration. The expression of the C5aR by astrocytes suggests new roles for the C5a anaphylatoxin in reactive astrogliosis to CNS injuries.
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Affiliation(s)
- S Sayah
- Federated Institute for Multidisciplinary Research on Peptides (No. 23), INSERM U78, Bois-Guillaume, France
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17
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Akatsu H, Yamada T, Okada N, Yamamoto T, Yamashina M, Okada H. Unique expression of HRF20 (CD59) in human nervous tissue. Microbiol Immunol 1997; 41:321-9. [PMID: 9159406 DOI: 10.1111/j.1348-0421.1997.tb01208.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Damage to autologous tissue by complement is limited by several widely distributed membrane-associated glycoproteins which restrict the action of the complement in homologous species. These include decay accelerating factor (DAF), membrane cofactor protein (MCP) and 20 kDa homologous restriction factor (HRF20,CD59). Using immunohistochemical techniques, we examined the localization of these proteins in the central nervous system (CNS) and peripheral nervous system (PNS) using non-neurological human nervous tissue since some complement components have been demonstrated to be synthesized in the CNS. There was no evidence of parenchymal staining by anti-DAF or anti-MCP antibodies in either type of tissue except for the staining of the endothelium in capillaries. On the other hand, anti-HRF20 antibody clearly stained myelinated axons in the CNS as well as Schwann cells in the PNS. In addition, we detected positive staining by anti-DAF antibody in the PNS of a Paroxysmal nocturnal hemoglobinuria (PNH) patient who is genetically deficient in HRF20.
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Affiliation(s)
- H Akatsu
- Department of Molecular Biology, Nagoya City University School of Medicine, Nagoya, Aichi, Japan
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18
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Spiller OB, Moretto G, Kim SU, Morgan BP, Devine DV. Complement expression on astrocytes and astrocytoma cell lines: failure of complement regulation at the C3 level correlates with very low CD55 expression. J Neuroimmunol 1996; 71:97-106. [PMID: 8982108 DOI: 10.1016/s0165-5728(96)00136-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Primary fetal human astrocytes and an astrocytoma cell line, U373-MG, expressed membrane cofactor protein (CD46), CD59, and low levels of decay-accelerating factor (CD55). Astrocyte CD55 was capable of regulating C3 deposition on the cell surface; albeit at a lower level than primary human fibroblasts. Negligible complement-mediated lysis of primary astrocytes and the U373-MG cell line was observed, even when large amount of astrocyte-specific, complement-activating antibodies were bound to the cells. Blocking the function of CD59 on astrocytes resulted in a > 90% cell lysis, while equivalent lysis of fibroblasts could only be achieved with additional blocking of CD55.
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Affiliation(s)
- O B Spiller
- Department of Medical Biochemistry, University of Wales College of Medicine, Cardiff, UK
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19
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Eikelenboom P, Veerhuis R. The role of complement and activated microglia in the pathogenesis of Alzheimer's disease. Neurobiol Aging 1996; 17:673-80. [PMID: 8892339 DOI: 10.1016/0197-4580(96)00108-x] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A variety of inflammatory mediators including complement activation products, protease inhibitors, and cytokines are colocalized with beta-amyloid (A beta) deposits in the Alzeimer's disease (AD) brain. Activation products of the early complement components C1, C4, and C3 are always found in neuritic plaques and to a lesser extent in varying numbers of diffuse plaques. In contrast to these findings, no immunohistochemical evidence was obtained for the presence of the late complement components C7 and C9 and the complement membrane attack complex in the neuropathological lesions in AD brains. The mRNA encoding the late complement components C7 and C9 appears to be hardly or not detectable. These findings indicate that in AD the complement system does not act as an inflammatory mediator through membrane attack complex formation, but through the actions of the early complement products. In this review we focus on the role of complement in the pathological amyloid cascade in AD. In our opinion, the early complement activation products play a crucial role as mediators between the A beta deposits and the inflammatory responses leading to neurotoxicity.
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Affiliation(s)
- P Eikelenboom
- Graduate School Neurosciences Amsterdam, Research Institute Neurosciences Vrije Universiteit, Department of Psychiatry, Amsterdam, The Netherlands
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20
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Rogers CA, Gasque P, Piddlesden SJ, Okada N, Holers VM, Morgan BP. Expression and function of membrane regulators of complement on rat astrocytes in culture. Immunology 1996; 88:153-61. [PMID: 8707343 PMCID: PMC1456455 DOI: 10.1046/j.1365-2567.1996.d01-637.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Human astrocytes express CD59, decay accelerating factor and membrane cofactor protein to restrict the damaging effect of complement (C) activation on their cell surface. 5I2 antigen (5I2 Ag) is the functional analogue of the latter two proteins in rats. We here demonstrate the surface expression on rat astrocytes of CD59 and 5I2 Ag and use sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting to confirm their identity and to quantify expression. Rat CD59 (MW 20,000) was expressed at 720 x 10(3) molecules per cell and 5I2 Ag (MW 58,000 and 64,000) at 625 x 10(3) molecules per cell. Reverse transcription-polymerase chain reaction using specific oligonucleotide primers demonstrated expression of mRNA for each protein. Twenty-four-hour stimulation with inflammatory cytokines (interferon-gamma, tumour necrosis factor-alpha, interleukins-1 beta, -2 and -6) or phorbol myristate acetate had no significant effect on the level of expression of either protein as determined by Western blotting. Lysis caused by classical pathway activation of C in human or rat serum was enhanced by blocking the function of CD59 and 5I2 Ag on rat astrocytes with monoclonal antibodies.
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Affiliation(s)
- C A Rogers
- Department of Medical Biochemistry, University of Wales College of Medicine, Cardiff, UK
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21
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Lacy M, Jones J, Whittemore SR, Haviland DL, Wetsel RA, Barnum SR. Expression of the receptors for the C5a anaphylatoxin, interleukin-8 and FMLP by human astrocytes and microglia. J Neuroimmunol 1995; 61:71-8. [PMID: 7560015 DOI: 10.1016/0165-5728(95)00075-d] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The expression of chemotactic receptors in the central nervous system is largely unexplored. In this study, we examined human astrocytes and microglia as well as the conditionally immortalized human astrocyte cell line HSC2 for expression of the C5a-anaphylatoxin receptor (C5aR), the interleukin-8 receptor (IL-8R) and the f-Met-Leu-Phe receptor (FMLPR). Using flow cytometry, indirect immunofluorescence and RT-PCR analysis, we demonstrated that astrocytes, microglia and HSC2 cells contain specific RNA and express surface protein for all three chemotactic receptors. These are the first studies to demonstrate definitively the expression of these chemotactic receptors astrocytes and microglia, thereby expanding the types of cells known to express chemotactic receptors. Moreover, these data suggest that these chemotactic receptors may play an important role in mediating the inflammatory response and perhaps other yet undescribed biological phenomena in the central nervous system.
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MESH Headings
- Adult
- Amino Acid Sequence
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Astrocytes/metabolism
- Cells, Cultured
- Complement C5a/metabolism
- Gene Expression
- Humans
- In Vitro Techniques
- Interleukin-8/metabolism
- Microglia/metabolism
- Molecular Sequence Data
- N-Formylmethionine Leucyl-Phenylalanine/metabolism
- Peptides/chemistry
- RNA, Messenger/genetics
- Receptor, Anaphylatoxin C5a
- Receptors, Complement/genetics
- Receptors, Complement/metabolism
- Receptors, Formyl Peptide
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, Interleukin/genetics
- Receptors, Interleukin/metabolism
- Receptors, Interleukin-8A
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
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Affiliation(s)
- M Lacy
- Department of Microbiology, University of Alabama at Birmingham 35294, USA
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22
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Barnum SR. Complement biosynthesis in the central nervous system. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1995; 6:132-46. [PMID: 7548620 DOI: 10.1177/10454411950060020301] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Complement is an important effector arm of the human immune response. Binding of proteolytic fragments derived from activation of complement by specific receptors leads to responses as diverse as inflammation, opsonization, and B-cell activation. The importance of characterizing the expression and regulation of complement in the CNS is highlighted by growing evidence that complement plays a significant role in the pathogenesis of a variety of neurological diseases, such as multiple sclerosis and Alzheimer's disease. In vitro studies have demonstrated that astrocytes, the predominant glial cell type in the brain, are capable of expressing or producing a majority of the components of the complement system. Expression of many complement proteins synthesized by astrocytes is regulated by both pro- and anti-inflammatory cytokines, many of which are also produced by several cell types in the CNS. In addition to astrocytes, ependymal cells, endothelial cells, microglia, and neurons have recently been shown to synthesize various complement proteins or express complement receptors on their cell surfaces. Together, these studies demonstrate that several cell types throughout the brain have the potential to express complement and, in many cases, increase expression in response to mediators of the acute phase response. These studies suggest that complement may play a greater role in CNS immune responses than previously thought, and pave the way for better understanding of the dynamics of complement expression and regulation in vivo. Such understanding may lead to therapeutic manipulation of complement host defense functions in a variety of inflammatory and degenerative diseases in the CNS.
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Affiliation(s)
- S R Barnum
- Department of Microbiology, University of Alabama at Birmingham 35294, USA
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23
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Faustmann PM, Krause D, Dux R, Dermietzel R. Morphological study in the early stages of complement C5a fragment-induced experimental meningitis: activation of macrophages and astrocytes. Acta Neuropathol 1995; 89:239-47. [PMID: 7754744 DOI: 10.1007/bf00309339] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Subarachnoidal application of the complement C5a fragment was used to induce acute experimental meningitis in rabbits and rats within 30-60 min. The early stages of the cellular inflammatory response were studied by means of flow cytometry, transmission electron microscopy and immunofluorescence microscopy. Infiltration of polymorphonuclear leukocytes (PMN) into the subarachnoidal space was the earliest event of the inflammatory reaction. By morphological criteria we found that PMN interacted with cells of the mononuclear-macrophage lineage (MML) and the marginal astrocytes via pseudopodia, whereas the pial cells were not involved in early stages of the inflammatory response. The number of invaded MML that were positive with the ED2 marker increased, indicating the hematogenous origin of the immigrating cell population. PMN were found to infiltrate the perivascular space of the marginal arterial vessel segments. This perivascular infiltration was assumed to be the first manifestation of cerebral vasculitis. The intimate association of resident cerebral cells (astrocytes) with invading PMN and MML is suggestive of a transient interaction of these cell types.
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Affiliation(s)
- P M Faustmann
- Department of Neurology, University of Essen, Germany
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24
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Abstract
Measles virus normally infects only primate cells. The receptor for measles virus has recently been shown to be the complement regulator CD46, also known as membrane cofactor protein. Transfection of rodent cells with human CD46 renders them susceptible to the virus, suggesting that transgenic animals may prove useful for testing antiviral agents and vaccines.
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Affiliation(s)
- R E Dörig
- Biotechnology Research Institute, National Research Council of Canada, Montréal
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