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Xing Y, Zhang D, Fang L, Wang J, Liu C, Wu D, Liu X, Wang X, Min W. Complement in Human Brain Health: Potential of Dietary Food in Relation to Neurodegenerative Diseases. Foods 2023; 12:3580. [PMID: 37835232 PMCID: PMC10572247 DOI: 10.3390/foods12193580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/21/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
The complement pathway is a major component of the innate immune system, which is critical for recognizing and clearing pathogens that rapidly react to defend the body against external pathogens. Many components of this pathway are expressed throughout the brain and play a beneficial role in synaptic pruning in the developing central nervous system (CNS). However, excessive complement-mediated synaptic pruning in the aging or injured brain may play a contributing role in a wide range of neurodegenerative diseases. Complement Component 1q (C1q), an initiating recognition molecule of the classical complement pathway, can interact with a variety of ligands and perform a range of functions in physiological and pathophysiological conditions of the CNS. This review considers the function and immunomodulatory mechanisms of C1q; the emerging role of C1q on synaptic pruning in developing, aging, or pathological CNS; the relevance of C1q; the complement pathway to neurodegenerative diseases; and, finally, it summarizes the foods with beneficial effects in neurodegenerative diseases via C1q and complement pathway and highlights the need for further research to clarify these roles. This paper aims to provide references for the subsequent study of food functions related to C1q, complement, neurodegenerative diseases, and human health.
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Affiliation(s)
- Yihang Xing
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China; (Y.X.); (D.Z.); (L.F.); (J.W.); (C.L.); (D.W.); (X.L.)
| | - Dingwen Zhang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China; (Y.X.); (D.Z.); (L.F.); (J.W.); (C.L.); (D.W.); (X.L.)
| | - Li Fang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China; (Y.X.); (D.Z.); (L.F.); (J.W.); (C.L.); (D.W.); (X.L.)
| | - Ji Wang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China; (Y.X.); (D.Z.); (L.F.); (J.W.); (C.L.); (D.W.); (X.L.)
| | - Chunlei Liu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China; (Y.X.); (D.Z.); (L.F.); (J.W.); (C.L.); (D.W.); (X.L.)
| | - Dan Wu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China; (Y.X.); (D.Z.); (L.F.); (J.W.); (C.L.); (D.W.); (X.L.)
| | - Xiaoting Liu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China; (Y.X.); (D.Z.); (L.F.); (J.W.); (C.L.); (D.W.); (X.L.)
| | - Xiyan Wang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China; (Y.X.); (D.Z.); (L.F.); (J.W.); (C.L.); (D.W.); (X.L.)
| | - Weihong Min
- College of Food and Health, Zhejiang A&F University, Hangzhou 311300, China
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Guan PP, Ge TQ, Wang P. As a Potential Therapeutic Target, C1q Induces Synapse Loss Via Inflammasome-activating Apoptotic and Mitochondria Impairment Mechanisms in Alzheimer's Disease. J Neuroimmune Pharmacol 2023; 18:267-284. [PMID: 37386257 DOI: 10.1007/s11481-023-10076-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 06/16/2023] [Indexed: 07/01/2023]
Abstract
C1q, the initiator of the classical pathway of the complement system, is activated during Alzheimer's disease (AD) development and progression and is especially associated with the production and deposition of β-amyloid protein (Aβ) and phosphorylated tau in β-amyloid plaques (APs) and neurofibrillary tangles (NFTs). Activation of C1q is responsible for induction of synapse loss, leading to neurodegeneration in AD. Mechanistically, C1q could activate glial cells, which results in the loss of synapses via regulation of synapse pruning and phagocytosis in AD. In addition, C1q induces neuroinflammation by inducing proinflammatory cytokine secretion, which is partially mediated by inflammasome activation. Activation of inflammasomes might mediate the effects of C1q on induction of synapse apoptosis. On the other hand, activation of C1q impairs mitochondria, which hinders the renovation and regeneration of synapses. All these actions of C1q contribute to the loss of synapses during neurodegeneration in AD. Therefore, pharmacological, or genetic interventions targeting C1q may provide potential therapeutic strategies for combating AD.
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Affiliation(s)
- Pei-Pei Guan
- College of Life and Health Sciences, Northeastern University, 110819, Shenyang, People's Republic of China
| | - Tong-Qi Ge
- College of Life and Health Sciences, Northeastern University, 110819, Shenyang, People's Republic of China
| | - Pu Wang
- College of Life and Health Sciences, Northeastern University, 110819, Shenyang, People's Republic of China.
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Croft CL, Futch HS, Moore BD, Golde TE. Organotypic brain slice cultures to model neurodegenerative proteinopathies. Mol Neurodegener 2019; 14:45. [PMID: 31791377 PMCID: PMC6889333 DOI: 10.1186/s13024-019-0346-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/13/2019] [Indexed: 01/30/2023] Open
Abstract
Organotypic slice cultures of brain or spinal cord have been a longstanding tool in neuroscience research but their utility for understanding Alzheimer's disease (AD) and other neurodegenerative proteinopathies has only recently begun to be evaluated. Organotypic brain slice cultures (BSCs) represent a physiologically relevant three-dimensional model of the brain. BSCs support all the central nervous system (CNS) cell types and can be produced from brain areas involved in neurodegenerative disease. BSCs can be used to better understand the induction and significance of proteinopathies underlying the development and progression of AD and other neurodegenerative disorders, and in the future may serve as bridging technologies between cell culture and in vivo experiments for the development and evaluation of novel therapeutic targets and strategies. We review the initial development and general use of BSCs in neuroscience research and highlight the advantages of these cultures as an ex vivo model. Subsequently we focus on i) BSC-based modeling of AD and other neurodegenerative proteinopathies ii) use of BSCs to understand mechanisms underlying these diseases and iii) how BSCs can serve as tools to screen for suitable therapeutics prior to in vivo investigations. Finally, we will examine i) open questions regarding the use of such cultures and ii) how emerging technologies such as recombinant adeno-associated viruses (rAAV) may be combined with these models to advance translational research relevant to neurodegenerative disorders.
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Affiliation(s)
- C L Croft
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.,Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - H S Futch
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.,Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - B D Moore
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.,Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - T E Golde
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL, 32610, USA. .,Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL, 32610, USA. .,McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.
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Cho K. Emerging Roles of Complement Protein C1q in Neurodegeneration. Aging Dis 2019; 10:652-663. [PMID: 31165008 PMCID: PMC6538225 DOI: 10.14336/ad.2019.0118] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 01/18/2019] [Indexed: 12/19/2022] Open
Abstract
The innate immune system is an ancient and primary component system that rapidly reacts to defend the body against external pathogens. C1 is the initial responder of classical pathway of the innate immune system. C1 is comprised of C1q, C1r, and C1s. Among them, C1q is known to interact with diverse ligands, which can perform various functions in physiological and pathophysiological conditions. Because C1q participates in the clearance of pathogens, its interaction with novel receptors is expected to facilitate apoptosis induction, which could prevent the onset or progression of neurodegenerative diseases and could delay the aging process. Because senescence-associated secreting phenotype determinants are generally inflammatory cytokines or immune factors to activate immune cells. In the central nervous system, C1q has diverse neuroprotective roles against pathogens and inflammation. Most of neurodegenerative diseases show region specific pathology feature in the brain. It has been suggested the evidences that the active site and amount of C1q may be disease specific. This review considers currently the emerging and under-recognized roles of C1q in neurodegeneration and highlights the need for further research to clarify these roles. Future studies on the roles of C1q in regulating disease progression should consider these aspects, including the age-dependent onset time of each neurodegenerative disease progression.
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Affiliation(s)
- Kyoungjoo Cho
- Department of Life Science, Kyonggi University, Suwon, South Korea
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Let's make microglia great again in neurodegenerative disorders. J Neural Transm (Vienna) 2017; 125:751-770. [PMID: 29027011 DOI: 10.1007/s00702-017-1792-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 09/18/2017] [Indexed: 12/12/2022]
Abstract
All of the common neurodegenerative disorders-Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and prion diseases-are characterized by accumulation of misfolded proteins that trigger activation of microglia; brain-resident mononuclear phagocytes. This chronic form of neuroinflammation is earmarked by increased release of myriad cytokines and chemokines in patient brains and biofluids. Microglial phagocytosis is compromised early in the disease process, obfuscating clearance of abnormal proteins. This review identifies immune pathologies shared by the major neurodegenerative disorders. The overarching concept is that aberrant innate immune pathways can be targeted for return to homeostasis in hopes of coaxing microglia into clearing neurotoxic misfolded proteins.
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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: 225] [Impact Index Per Article: 32.1] [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.
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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.
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Abstract
C1q, historically viewed as the initiating component of the classical complement pathway, also exhibits a variety of complement-independent activities in both innate and acquired immunity. Recent studies focusing on C1q's suppressive role in the immune system have provided new insight into how abnormal C1q expression and bioactivity may contribute to autoimmunity. In particular, molecular networks involving C1q interactions with cell surface receptors and other ligands are emerging as mechanisms involved in C1q's modulation of immunity. Here, we discuss the role of C1q in controlling immune cell function, including recently elucidated mechanisms of action, and suggest how these processes are critical for maintaining tissue homeostasis under steady-state conditions and in preventing autoimmunity.
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Affiliation(s)
- Myoungsun Son
- Center for Autoimmune and Musculoskeletal Diseases, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Betty Diamond
- Center for Autoimmune and Musculoskeletal Diseases, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA.
| | - Frances Santiago-Schwarz
- Center for Autoimmune and Musculoskeletal Diseases, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
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Astrocyte-Microglia Cross Talk through Complement Activation Modulates Amyloid Pathology in Mouse Models of Alzheimer's Disease. J Neurosci 2016; 36:577-89. [PMID: 26758846 DOI: 10.1523/jneurosci.2117-15.2016] [Citation(s) in RCA: 372] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
UNLABELLED Increasing evidence supports a role of neuroinflammation in the pathogenesis of Alzheimer's disease (AD). Previously, we identified a neuron-glia signaling pathway whereby Aβ acts as an upstream activator of astroglial nuclear factor kappa B (NF-κB), leading to the release of complement C3, which acts on the neuronal C3a receptor (C3aR) to influence dendritic morphology and cognitive function. Here we report that astrocytic complement activation also regulates Aβ dynamics in vitro and amyloid pathology in AD mouse models through microglial C3aR. We show that in primary microglial cultures, acute C3 or C3a activation promotes, whereas chronic C3/C3a treatment attenuates, microglial phagocytosis and that the effect of chronic C3 exposure can be blocked by cotreatment with a C3aR antagonist and by genetic deletion of C3aR. We further demonstrate that Aβ pathology and neuroinflammation in amyloid precursor protein (APP) transgenic mice are worsened by astroglial NF-κB hyperactivation and resulting C3 elevation, whereas treatment with the C3aR antagonist (C3aRA) ameliorates plaque load and microgliosis. Our studies define a complement-dependent intercellular cross talk in which neuronal overproduction of Aβ activates astroglial NF-κB to elicit extracellular release of C3. This promotes a pathogenic cycle by which C3 in turn interacts with neuronal and microglial C3aR to alter cognitive function and impair Aβ phagocytosis. This feedforward loop can be effectively blocked by C3aR inhibition, supporting the therapeutic potential of C3aR antagonists under chronic neuroinflammation conditions. SIGNIFICANCE STATEMENT The complement pathway is activated in Alzheimer's disease. Here we show that the central complement factor C3 secreted from astrocytes interacts with microglial C3a receptor (C3aR) to mediate β-amyloid pathology and neuroinflammation in AD mouse models. Our study provides support for targeting C3aR as a potential therapy for Alzheimer's disease.
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Kouser L, Madhukaran SP, Shastri A, Saraon A, Ferluga J, Al-Mozaini M, Kishore U. Emerging and Novel Functions of Complement Protein C1q. Front Immunol 2015; 6:317. [PMID: 26175731 PMCID: PMC4484229 DOI: 10.3389/fimmu.2015.00317] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/02/2015] [Indexed: 02/02/2023] Open
Abstract
Complement protein C1q, the recognition molecule of the classical pathway, performs a diverse range of complement and non-complement functions. It can bind various ligands derived from self, non-self, and altered self and modulate the functions of immune and non-immune cells including dendritic cells and microglia. C1q involvement in the clearance of apoptotic cells and subsequent B cell tolerance is more established now. Recent evidence appears to suggest that C1q plays an important role in pregnancy where its deficiency and dysregulation can have adverse effects, leading to preeclampsia, missed abortion, miscarriage or spontaneous loss, and various infections. C1q is also produced locally in the central nervous system, and has a protective role against pathogens and possible inflammatory functions while interacting with aggregated proteins leading to neurodegenerative diseases. C1q role in synaptic pruning, and thus CNS development, its anti-cancer effects as an immune surveillance molecule, and possibly in aging are currently areas of extensive research.
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Affiliation(s)
- Lubna Kouser
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK
| | - Shanmuga Priyaa Madhukaran
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK ; Centre for Biotechnology and Bioinformatics, Jawaharlal Nehru Institute for Advanced Studies, School of Life Sciences , Secunderabad , India
| | - Abhishek Shastri
- St. Ann's Hospital, Dorset Healthcare University NHS Foundation Trust , Poole , UK
| | - Anuvinder Saraon
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK
| | - Janez Ferluga
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK
| | - Maha Al-Mozaini
- Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre , Riyadh , Saudi Arabia
| | - Uday Kishore
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK
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Peterson SL, Anderson AJ. Complement and spinal cord injury: traditional and non-traditional aspects of complement cascade function in the injured spinal cord microenvironment. Exp Neurol 2014; 258:35-47. [PMID: 25017886 DOI: 10.1016/j.expneurol.2014.04.028] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 04/14/2014] [Accepted: 04/28/2014] [Indexed: 12/21/2022]
Abstract
The pathology associated with spinal cord injury (SCI) is caused not only by primary mechanical trauma, but also by secondary responses of the injured CNS. The inflammatory response to SCI is robust and plays an important but complex role in the progression of many secondary injury-associated pathways. Although recent studies have begun to dissect the beneficial and detrimental roles for inflammatory cells and proteins after SCI, many of these neuroimmune interactions are debated, not well understood, or completely unexplored. In this regard, the complement cascade is a key component of the inflammatory response to SCI, but is largely underappreciated, and our understanding of its diverse interactions and effects in this pathological environment is limited. In this review, we discuss complement in the context of SCI, first in relation to traditional functions for complement cascade activation, and then in relation to novel roles for complement proteins in a variety of models.
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Affiliation(s)
- Sheri L Peterson
- Sue & Bill Gross Stem Cell Center, University of California, Irvine, Irvine, CA 92697, USA; Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA; Department of Anatomy & Neurobiology, University of California, Irvine, Irvine, CA 92697, USA
| | - Aileen J Anderson
- Sue & Bill Gross Stem Cell Center, University of California, Irvine, Irvine, CA 92697, USA; Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA; Department of Anatomy & Neurobiology, University of California, Irvine, Irvine, CA 92697, USA; Department of Physical Medicine and Rehabilitation, University of California, Irvine, Irvine, CA 92697, USA.
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Shastri A, Bonifati DM, Kishore U. Innate immunity and neuroinflammation. Mediators Inflamm 2013; 2013:342931. [PMID: 23843682 PMCID: PMC3697414 DOI: 10.1155/2013/342931] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/15/2013] [Indexed: 01/07/2023] Open
Abstract
Inflammation of central nervous system (CNS) is usually associated with trauma and infection. Neuroinflammation occurs in close relation to trauma, infection, and neurodegenerative diseases. Low-level neuroinflammation is considered to have beneficial effects whereas chronic neuroinflammation can be harmful. Innate immune system consisting of pattern-recognition receptors, macrophages, and complement system plays a key role in CNS homeostasis following injury and infection. Here, we discuss how innate immune components can also contribute to neuroinflammation and neurodegeneration.
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Affiliation(s)
- Abhishek Shastri
- Centre for Infection, Immunity and Disease Mechanisms, Heinz Wolff Building, Brunel University, London UB8 3PH, UK
| | - Domenico Marco Bonifati
- Unit of Neurology, Department of Neurological Disorders, Santa Chiara Hospital, Largo Medaglie d'oro 1, 38100 Trento, Italy
| | - Uday Kishore
- Centre for Infection, Immunity and Disease Mechanisms, Heinz Wolff Building, Brunel University, London UB8 3PH, UK
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Benoit ME, Hernandez MX, Dinh ML, Benavente F, Vasquez O, Tenner AJ. C1q-induced LRP1B and GPR6 proteins expressed early in Alzheimer disease mouse models, are essential for the C1q-mediated protection against amyloid-β neurotoxicity. J Biol Chem 2012; 288:654-65. [PMID: 23150673 DOI: 10.1074/jbc.m112.400168] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Complement protein C1q is induced in the brain in response to a variety of neuronal injuries, including Alzheimer disease (AD), and blocks fibrillar amyloid-β (fAβ) neurotoxicity in vitro. Here, we show that C1q protects immature and mature primary neurons against fAβ toxicity, and we report for the first time that C1q prevents toxicity induced by oligomeric forms of amyloid-β (Aβ). Gene expression analysis reveals C1q-activated phosphorylated cAMP-response element-binding protein and AP-1, two transcription factors associated with neuronal survival and neurite outgrowth, and increased LRP1B and G protein-coupled receptor 6(GPR6) expression in fAβ-injured neurons. Silencing of cAMP-response element-binding protein, LRP1B or GPR6 expression inhibited C1q-mediated neuroprotection from fAβ-induced injury. In addition, C1q altered the association of oligomeric Aβ and fAβ with neurons. In vivo, increased hippocampal expression of C1q, LRP1B, and GPR6 is observed as early as 2 months of age in the 3 × Tg mouse model of AD, whereas no such induction of LRP1B and GPR6 was seen in C1q-deficient AD mice. In contrast, expression of C1r and C1s, proteases required to activate the classical complement pathway, and C3 showed a significant age-dependent increase only after 10-13 months of age when Aβ plaques start to accumulate in this AD model. Thus, our results identify pathways by which C1q, up-regulated in vivo early in response to injury without the coordinate induction of other complement components, can induce a program of gene expression that promotes neuroprotection and thus may provide protection against Aβ in preclinical stages of AD and other neurodegenerative processes.
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Affiliation(s)
- Marie E Benoit
- Department of Molecular Biology and Biochemistry, of California at Irvine, Irvine, California 92697, USA
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Bi BT, Lin HB, Cheng YF, Zhou H, Lin T, Zhang MZ, Li TJ, Xu JP. Promotion of β-amyloid production by C-reactive protein and its implications in the early pathogenesis of Alzheimer's disease. Neurochem Int 2011; 60:257-66. [PMID: 22202667 DOI: 10.1016/j.neuint.2011.12.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 12/06/2011] [Accepted: 12/12/2011] [Indexed: 10/14/2022]
Abstract
C-reactive protein (CRP) and β-amyloid protein (Aβ) are involved in the development of Alzheimer's disease (AD). However, the relationship between CRP and Aβ production is unclear. In vitro and in vivo experiments were performed to investigate the association of CRP with Aβ production. Using the rat adrenal pheochromocytoma cell line (PC12 cells) to mimic neurons, cytotoxicity was evaluated by cell viability and supernatant lactate dehydrogenase (LDH) activity. The levels of amyloid precursor protein (APP), beta-site APP cleaving enzyme (BACE-1), and presenilins (PS-1 and PS-2) were investigated using real-time polymerase chain reaction and Western blotting analysis. Aβ1-42 was measured by enzyme-linked immunosorbent assay. The relevance of CRP and Aβ as well as potential mechanisms were studied using APP/PS1 transgenic (Tg) mice. Treatment with 0.5-4.0 μM CRP for 48 h decreased cell viability and increased LDH leakage in PC12 cells. Incubation with CRP at a sub-toxic concentration of 0.2 μM increased the mRNA levels of APP, BACE-1, PS-1, and PS-2, as well as Aβ1-42 production. CRP inhibitor reversed the CRP-induced upregulations of the mRNA levels of APP, BACE-1, PS-1, and PS-2, and the protein levels of APP, BACE-1, PS-1, and Aβ1-42, but did not reversed Aβ1-42 cytotoxicity. The cerebral levels of CRP and Aβ1-42 in APP/PS1 Tg mice were positively correlated, accompanied with the elevated mRNA expressions of serum amyloid P component (SAP), complement component 1q (C1q), and tumor necrosis factor-α (TNF-α). These results suggest that CRP cytotoxicity is associated with Aβ formation and Aβ-related markers expressions; CRP and Aβ were relevant in early-stage AD; CRP may be an important trigger in AD pathogenesis.
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Affiliation(s)
- Bing-Tian Bi
- Department of Pharmacology, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
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14
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Complement protein C1q-mediated neuroprotection is correlated with regulation of neuronal gene and microRNA expression. J Neurosci 2011; 31:3459-69. [PMID: 21368058 DOI: 10.1523/jneurosci.3932-10.2011] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Activation of the complement cascade, a powerful effector mechanism of the innate immune system, is associated with neuroinflammation but also with elimination of inappropriate synapses during development. Synthesis of C1q, a recognition component of the complement system, occurs in brain during ischemia/reperfusion and Alzheimer's disease, suggesting that C1q may be a response to injury. In vitro, C1q, in the absence of other complement proteins, improves neuronal viability and neurite outgrowth and prevents β-amyloid-induced neuronal death, suggesting that C1q may have a direct neuroprotective role. Here, investigating the molecular basis for this neuroprotection in vitro, addition of C1q to rat primary cortical neurons significantly upregulated expression of genes associated with cholesterol metabolism, such as cholesterol-25-hydroxylase and insulin induced gene 2, and transiently decreased cholesterol levels in neurons, known to facilitate neurite outgrowth. In addition, the expression of syntaxin-3 and its functional association with synaptosomal-associated protein 25 was increased. C1q also increased the nuclear translocation of cAMP response element-binding protein and CCAAT/enhancer-binding protein-δ (C/EBP-δ), two transcription factors involved in nerve growth factor (NGF) expression and downregulated specific microRNAs, including let-7c that is predicted to target (and thus inhibit) NGF and neurotrophin-3 (NT-3) mRNA. Accordingly, C1q increased expression of NGF and NT-3, and small interfering RNA inhibition of C/EBP-δ, NGF, or NT-3 expression prevented the C1q-dependent neurite outgrowth. No such neuroprotective effect is seen in the presence of C3a or C5a. Finally, the induced neuronal gene expression required conformationally intact C1q. These results show that C1q can directly promote neuronal survival, thereby demonstrating new interactions between immune proteins and neuronal cells that may facilitate neuroprotection.
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Dual induction of TREM2 and tolerance-related transcript, Tmem176b, in amyloid transgenic mice: implications for vaccine-based therapies for Alzheimer's disease. ASN Neuro 2010; 2:e00037. [PMID: 20640189 PMCID: PMC2905103 DOI: 10.1042/an20100010] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 06/07/2010] [Accepted: 06/14/2010] [Indexed: 12/12/2022] Open
Abstract
Vaccine-based autoimmune (anti-amyloid) treatments are currently being examined for their therapeutic potential in Alzheimer's disease. In the present study we examined, in a transgenic model of amyloid pathology, the expression of two molecules previously implicated in decreasing the severity of autoimmune responses: TREM2 (triggering receptor expressed on myeloid cells 2) and the intracellular tolerance-associated transcript, Tmem176b (transmembrane domain protein 176b). In situ hybridization analysis revealed that both molecules were highly expressed in plaque-associated microglia, but their expression defined two different zones of plaque-associated activation. Tmem176b expression was highest in the inner zone of amyloid plaques, whereas TREM2 expression was highest in the outer zone. Induced expression of TREM2 occurred co-incident with detection of thioflavine-S-positive amyloid deposits. Transfection studies revealed that expression of TREM2 correlated negatively with motility, but correlated positively with the ability of microglia to stimulate CD4+ T-cell proliferation, TNF (tumour necrosis factor) and CCL2 (chemokine ligand 2) production, but not IFNγ (interferon γ) production. TREM2 expression also showed a positive correlation with amyloid phagocytosis in unactivated cells. However, activating cells with LPS (lipopolysaccharide), but not IFNγ, reduced the correlation between TREM2 expression and phagocytosis. Transfection of Tmem176b into both microglial and macrophage cell lines increased apoptosis. Taken together, these data suggest that, in vivo, Tmem176b+ cells in closest apposition to amyloid may be the least able to clear amyloid. Conversely, the phagocytic TREM2+ microglia on the plaque outer zones are positioned to capture and present self-antigens to CNS (central nervous system)-infiltrating lymphocytes without promoting pro-inflammatory lymphocyte responses. Instead, plaque-associated TREM2+ microglia have the potential to evoke neuroprotective immune responses that may serve to support CNS function during pro-inflammatory anti-amyloid immune therapies.
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Key Words
- Aβ, amyloid β peptide
- CCL2, chemokine ligand 2
- CFSE, carboxyfluorescein succinimidyl ester
- CNS, central nervous system
- Clast1
- DAMP, danger-associated molecular pattern
- DMEM, Dulbecco's modified Eagle's medium
- EAE, experimentally induced autoimmune encephalomyelitis
- FBS, fetal bovine serum
- GFP, green fluorescent protein
- HPRT, hypoxanthine phosphoribosyl transferase
- IFNγ, interferon γ
- IL, interleukin
- KO, knockout
- LPS, lipopolysaccharide
- PFA, paraformaldehyde
- TNF, tumour necrosis factor
- TREM2, triggering receptor expressed on myeloid cells 2
- Thio-S, thioflavine-S
- Tmem176b, transmembrane domain protein 176b
- Torid
- WT, wild-type
- antigen presentation
- autoimmunity
- neuroinflammation
- qPCR, quantitative PCR
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Ager RR, Fonseca MI, Chu SH, Sanderson SD, Taylor SM, Woodruff TM, Tenner AJ. Microglial C5aR (CD88) expression correlates with amyloid-beta deposition in murine models of Alzheimer's disease. J Neurochem 2010; 113:389-401. [PMID: 20132482 DOI: 10.1111/j.1471-4159.2010.06595.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD), a progressive neurodegenerative disease characterized by the accumulation of amyloid-beta protein and neuronal loss, is the leading cause of age-related dementia in the world today. The disease is also associated with neuroinflammation, robust activation of astrocytes and microglia, and evidence of activation of the complement system, localized with both fibrillar amyloid-beta (fAbeta) plaques and tangles. The observations are consistent with a complement-dependent component of AD progression. We have previously shown that inhibition of the major complement receptor for C5a (CD88) with the antagonist PMX205 results in a significant reduction in pathology in two mouse models of AD. To further characterize the role of complement in AD-related neuroinflammation, we examined the age- and disease-associated expression of CD88 in brain of transgenic mouse models of AD and the influence of PMX205 on the presence of various complement activation products using flow cytometry, western blot, and immunohistochemistry. CD88 was found to be up-regulated in microglia, in the immediate vicinity of amyloid plaques. While thioflavine plaque load and glial recruitment is significantly reduced after treatment with PMX205, C1q remains co-localized with fAbeta plaques and C3 is still expressed by the recruited astrocytes. Thus, with PMX205, potentially beneficial activities of these early complement components may remain intact, while detrimental activities resulting from C5a-CD88 interaction are inhibited. This further supports the targeted inhibition of specific complement mediated activities as an approach for AD therapy.
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Affiliation(s)
- Rahasson R Ager
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, USA
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17
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Nguyen HX, Galvan MD, Anderson AJ. Characterization of early and terminal complement proteins associated with polymorphonuclear leukocytes in vitro and in vivo after spinal cord injury. J Neuroinflammation 2008; 5:26. [PMID: 18578885 PMCID: PMC2443364 DOI: 10.1186/1742-2094-5-26] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Accepted: 06/25/2008] [Indexed: 02/01/2023] Open
Abstract
Background The complement system has been suggested to affect injury or disease of the central nervous system (CNS) by regulating numerous physiological events and pathways. The activation of complement following traumatic CNS injury can also result in the formation and deposition of C5b-9 membrane attack complex (C5b-9/MAC), causing cell lysis or sublytic effects on vital CNS cells. Although complement proteins derived from serum/blood-brain barrier breakdown can contribute to injury or disease, infiltrating immune cells may represent an important local source of complement after injury. As the first immune cells to infiltrate the CNS within hours post-injury, polymorphonuclear leukocytes (PMNs) may affect injury through mechanisms associated with complement-mediated events. However, the expression/association of both early and terminal complement proteins by PMNs has not been fully characterized in vitro, and has not observed previously in vivo after traumatic spinal cord injury (SCI). Method We investigated the expression of complement mRNAs using rt-PCR and the presence of complement proteins associated with PMNs using immunofluroescence and quantitative flow cytometry. Results Stimulated or unstimulated PMNs expressed mRNAs encoding for C1q, C3, and C4, but not C5, C6, C7 or C9 in culture. Complement protein C1q or C3 was also detected in less than 30% of cultured PMNs. In contrast, over 70% of PMNs that infiltrated the injured spinal cord were associated with C1q, C3, C7 and C5b-9/MAC 3 days post-SCI. The localization/association of C7 or C5b-9/MAC with infiltrating PMNs in the injured spinal cord suggests the incorporation or internalization of C7 or C5b-9/MAC bound cellular debris by infiltrating PMNs because C7 and C5b-9/MAC were mostly localized to granular vesicles within PMNs at the spinal cord epicenter region. Furthermore, PMN presence in the injured spinal cord was observed for many weeks post-SCI, suggesting that this infiltrating cell population could chronically affect complement-mediated events and SCI pathogenesis after trauma. Conclusion Data presented here provide the first characterization of early and terminal complement proteins associated with PMNs in vitro and in vivo after SCI. Data also suggest a role for PMNs in the local internalization or deliverance of complement and complement activation in the post-SCI environment.
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Affiliation(s)
- Hal X Nguyen
- Physical Medicine & Rehabilitation, 1105 Gillespie Neuroscience Research Facility, University of California, Irvine, CA 92697-4292, USA.
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18
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Pisalyaput K, Tenner AJ. Complement component C1q inhibits beta-amyloid- and serum amyloid P-induced neurotoxicity via caspase- and calpain-independent mechanisms. J Neurochem 2007; 104:696-707. [PMID: 17986223 DOI: 10.1111/j.1471-4159.2007.05012.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Alzheimer's disease is a neurodegenerative disorder characterized by neuronal loss, beta-amyloid (Abeta) plaques, and neurofibrillary tangles. Complement protein C1q has been found associated with fibrillar Abeta deposits, however the exact contributions of C1q to Alzheimer's disease is still unknown. There is evidence that C1q, as an initiator of the inflammatory complement cascade, may accelerate disease progression. However, neuronal C1q synthesis is induced after injury/infection suggesting that it may be a beneficial response to injury. In this study, we report that C1q enhances the viability of neurons in culture and protects neurons against Abeta- and serum amyloid P (SAP)-induced neurotoxicity. Investigation of potential signaling pathways indicates that caspase and calpain are activated by Abeta, but C1q had no effect on either of these pathways. Interestingly, SAP did not induce caspase and calpain activation, suggesting that C1q neuroprotection is in distinct from caspase and calpain pathways. In contrast to Abeta- and SAP-induced neurotoxicity, neurotoxicity induced by etoposide or FCCP was unaffected by the addition of C1q, indicating pathway selectivity for C1q neuroprotection. These data support a neuroprotective role for C1q which should be further investigated to uncover mechanisms which may be therapeutically targeted to slow neurodegeneration via direct inhibition of neuronal loss.
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Affiliation(s)
- Karntipa Pisalyaput
- Department of Molecular Biology and Biochemistry, Institute for Brain Aging and Dementia, Center for Immunology, University of California, Irvine, California 92697, USA
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19
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Nicolay NH, Hertle D, Boehmerle W, Heidrich FM, Yeckel M, Ehrlich BE. Inositol 1,4,5 trisphosphate receptor and chromogranin B are concentrated in different regions of the hippocampus. J Neurosci Res 2007; 85:2026-36. [PMID: 17471556 PMCID: PMC2945619 DOI: 10.1002/jnr.21328] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Calcium (Ca(2+)) release from intracellular stores plays a crucial role in many cellular functions in the brain. These intracellular signals have been shown to be transmitted within and between cells. We report a non-uniform distribution of proteins essential for Ca(2+) signaling in acutely prepared brain slice preparations and organotypic slice cultures, both made from rat hippocampus. The Type I inositol-1,4,5 trisphosphate receptor (InsP(3)R1) is the main InsP(3)R subtype in neurons. Immunohistochemistry experiments showed a prominent expression of InsP(3)R1 in the CA1 region of the hippocampus whereas the CA3 region and dentate gyrus (DG) showed only moderate immunoreactivity. In contrast, chromogranin B (CGB), a protein binding to the InsP(3)R1 on the luminal side of the endoplasmic reticular membrane was enriched in the CA3 region whereas DG and the CA1 region showed only faint CGB signals. The neuronal kinases leading to the formation of inositol-1,4,5 trisphosphate (InsP(3)), phosphatidylinositol-4-kinase (PI4K), and phosphatidylinositol-4-phosphate-5-kinase (PIPK), showed strong immunoreactivity throughout all hippocampal cell fields with differences in the subcellular distribution. Moreover, a distinct band of strong CGB and PIPK immunoreactivity was observed in the CA3 region that coincides with the mossy fiber tract (stratum lucidum). These data show differential expression of the components of the signaling toolkit leading to InsP(3)-mediated Ca(2+) release in cells of the hippocampus. The regulation of these differences may play an important role in various neuropathologic conditions such as Alzheimer's disease, epilepsy, or schizophrenia.
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Affiliation(s)
- Nils H. Nicolay
- Departments of Pharmacology, Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
- Department of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | - Daniel Hertle
- Department of Neurobiology, Yale University, New Haven, Connecticut
| | - Wolfgang Boehmerle
- Departments of Pharmacology, Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
- Neuroscience Research Centre, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Felix M. Heidrich
- Departments of Pharmacology, Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
- Department of Pharmacology and Toxicology, University of Technology Dresden, Dresden, Germany
| | - Mark Yeckel
- Department of Neurobiology, Yale University, New Haven, Connecticut
| | - Barbara E. Ehrlich
- Departments of Pharmacology, Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
- Correspondence to: Dr. Barbara E. Ehrlich, 333 Cedar Street, Yale University, Department of Pharmacology, New Haven, CT 06520-8066.
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20
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Ryman D, Gao Y, Lamb BT. Genetic loci modulating amyloid-beta levels in a mouse model of Alzheimer's disease. Neurobiol Aging 2007; 29:1190-8. [PMID: 17400334 PMCID: PMC3745768 DOI: 10.1016/j.neurobiolaging.2007.02.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 01/23/2007] [Accepted: 02/10/2007] [Indexed: 11/17/2022]
Abstract
Genetic studies have demonstrated very high heritability for Alzheimer's disease (AD) risk in humans; however, these genetic contributions have proven extremely challenging to map in large studies of AD patients. Processing of the amyloid precursor protein (APP) to produce amyloid-beta (Abeta) peptide is increasingly believed to be of central importance in AD pathogenesis. Intriguingly, mice from the C57BL/6J and DBA2/J inbred strains carrying the R1.40 APP transgene produce identical levels of unprocessed APP, but demonstrate significant, heritable differences in Abeta levels. To identify specific loci responsible for the observed genetic control of Abeta metabolism in this model system, we have performed a whole-genome quantitative trait locus (QTL) mapping experiment on a total of 516 animals from a C57BL/6JxDBA/2J intercross using a dense set of SNP genetic markers. Our studies have identified three loci on mouse chromosomes 1, 2, and 7 showing significant or suggestive associations with brain Abeta levels, several of which contain regions syntenic to previous reports of linkage in human AD.
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Affiliation(s)
- Davis Ryman
- Lerner Research Institute, Cleveland Clinic Foundation, Department of Neurosciences NC3-164, 2045 East 89 Street, Cleveland, OH 44106 USA
- Case Western Reserve University School of Medicine, Department of Genetics, 10900 Euclid Avenue, Cleveland, OH 44106-4955 USA
| | - Yuan Gao
- Case Western Reserve University School of Medicine, Department of Genetics, 10900 Euclid Avenue, Cleveland, OH 44106-4955 USA
| | - Bruce T. Lamb
- Lerner Research Institute, Cleveland Clinic Foundation, Department of Neurosciences NC3-164, 2045 East 89 Street, Cleveland, OH 44106 USA
- Case Western Reserve University School of Medicine, Department of Genetics, 10900 Euclid Avenue, Cleveland, OH 44106-4955 USA
- Case Western Reserve University School of Medicine, Department of Neuroscience, 10900 Euclid Avenue, Cleveland, OH 44106-4955 USA
- Corresponding author. Fax: (216) 444-7927 Office: (216) 444-3592
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21
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Aronica E, Boer K, van Vliet EA, Redeker S, Baayen JC, Spliet WGM, van Rijen PC, Troost D, da Silva FHL, Wadman WJ, Gorter JA. Complement activation in experimental and human temporal lobe epilepsy. Neurobiol Dis 2007; 26:497-511. [PMID: 17412602 DOI: 10.1016/j.nbd.2007.01.015] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 12/21/2006] [Accepted: 01/12/2007] [Indexed: 10/23/2022] Open
Abstract
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.
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Affiliation(s)
- E Aronica
- Department of (Neuro) Pathology, Academic Medical Center, University of Amsterdam, The Netherlands
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22
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Tenner AJ, Fonseca MI. The Double-Edged Flower: Roles of Complement Protein C1q in Neurodegenerative Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 586:153-76. [PMID: 16893071 DOI: 10.1007/0-387-34134-x_11] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A role for the complement cascade in AD neuropathology was hypothesized over a decade ago, and the results of a significant number of in vitro studies are consistent with the involvement of this pathway in AD pathogenesis (reviewed in). Since C1q is colocalized with thioflavine-positive plaques and the C5b-9 complement membrane attack complex is detected in AD brain at autopsy, it is reasonable to hypothesize that complement activation has a role in the manifestation of AD either by its lytic capacity or as a trigger of glial infiltration and initiation of potentially damaging inflammation. The observed diminished glial activation and reduced loss of neuronal integrity in a murine model overexpressing mutant human APP but lacking the ability to activate the classical complement cascade provide the first direct evidence for a detrimental role of C1q, and presumably activation of the classical complement pathway in an animal model of AD. Research is now focused on generating mouse models that more closely mimic the human disease, so that the role of complement activation and inflammation on the behavioral/learning and memory dysfunction that occurs in this disease can be assessed. In addition, candidate therapies such as targeted inhibition of complement activation will need to be tested in these animal models as a step toward treatment of humans with the disease. However, it is important that the potential for a protective effect of C1q early on in disease progression should not be overlooked. Rather, strategies that enhance or mimic the protective effects of C1q as well as strategies that inhibit the detrimental processes should be fully investigated.
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Affiliation(s)
- Andrea J Tenner
- Department of Molecular Biology, Center for Immunology, University of California, Irvine, CA 92697, USA
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23
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Fraser DA, Arora M, Bohlson SS, Lozano E, Tenner AJ. Generation of inhibitory NFkappaB complexes and phosphorylated cAMP response element-binding protein correlates with the anti-inflammatory activity of complement protein C1q in human monocytes. J Biol Chem 2007; 282:7360-7. [PMID: 17209050 DOI: 10.1074/jbc.m605741200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The interaction of C1q with specific cells of the immune system induces activities, such as enhancement of phagocytosis in monocytes and stimulation of superoxide production in neutrophils. In contrast to some other monocyte activators, C1q itself does not induce pro-inflammatory cytokine production, but rather inhibits the lipopolysaccharide (LPS)-stimulated induction of certain pro-inflammatory cytokines and induces expression of interleukin-10. To investigate the molecular mechanism by which C1q exerts this effect on gene expression, the influence of C1q on the activation of transcription factors of the NFkappaB family and cAMP response element-binding protein (CREB) was assessed. C1q treatment increased kappaB binding activity in freshly isolated human monocytes in a time-dependent fashion as assessed by electrophoretic mobility shift assays. In antibody supershift experiments, anti-p50 antibody supershifted the C1q-induced NFkappaB complex, whereas anti-p65 antibody had little effect, suggesting that C1q induced the translocation of NFkappaB p50p50 homodimers. This is in contrast to the dominant induction of p65 containing complexes in parallel monocyte cultures stimulated with LPS. C1q treatment also induced cAMP response element (CRE)-binding activity as demonstrated by electrophoretic mobility shift assay, increased phosphorylation of CREB, and induction of CRE driven gene expression. In contrast, CREB activation was not detected in LPS-treated monocytes. These results suggest that C1q may modulate the cytokine profile expressed in response to inflammatory stimuli (e.g. LPS), by triggering inhibitory and/or competing signals. Because C1q and other defense collagens have been shown to enhance clearance of apoptotic cells, this regulatory pathway may be beneficial in avoiding autoimmunity and/or resolving inflammation.
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Affiliation(s)
- Deborah A Fraser
- Department of Molecular Biology and Biochemistry, Center for Immunology, University of California, Irvine, California 92697, USA
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24
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Bohlson SS, Fraser DA, Tenner AJ. Complement proteins C1q and MBL are pattern recognition molecules that signal immediate and long-term protective immune functions. Mol Immunol 2006; 44:33-43. [PMID: 16908067 DOI: 10.1016/j.molimm.2006.06.021] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 06/21/2006] [Accepted: 06/26/2006] [Indexed: 12/16/2022]
Abstract
C1q and mannose binding lectin, members of the "defense collagen" family, are pattern recognition molecules that can trigger rapid enhanced phagocytosis resulting in efficient containment of pathogens or clearance of cellular debris, apoptotic cells and immune complexes. In addition, interaction of C1q and mannose binding lectin with the phagocyte alters subsequent phagocyte cytokine synthesis, and thus may have important implications in directing acute inflammation as well as long-term protective immunity. The importance of the role of defense collagens in phagocytosis of apoptotic cells is highlighted by studies in vivo of mice deficient in C1q, pulmonary surfactant D and mannose binding lectin in which there is delayed clearance of apoptotic cells. Indeed, deficiency of C1q is a risk factor for the development of autoimmunity in both humans and mice, consistent with the hypothesis that inefficient clearance of apoptotic cells results in release of autoantigens and contributes to the pathology associated with autoimmune diseases such as systemic lupus erythematosus. Further understanding of the importance of C1q and mannose binding lectin in the clearance of apoptotic cells and regulation of cytokine synthesis and identification of the receptors implicated in mediating these processes should provide novel targets for therapeutic intervention in the control and manipulation of the immune response in terms of both host defense against infectious disease and tissue repair and remodeling.
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Affiliation(s)
- Suzanne S Bohlson
- Department of Molecular Biology and Biochemistry, Center for Immunology, University of California, Irvine, CA 92697, USA
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25
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Chong YH, Shin YJ, Lee EO, Kayed R, Glabe CG, Tenner AJ. ERK1/2 activation mediates Abeta oligomer-induced neurotoxicity via caspase-3 activation and tau cleavage in rat organotypic hippocampal slice cultures. J Biol Chem 2006; 281:20315-25. [PMID: 16714296 DOI: 10.1074/jbc.m601016200] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we investigated the molecular basis for the altered signal transduction associated with soluble amyloid beta-protein (Abeta) oligomer-mediated neurotoxicity in the hippocampus, which is primarily linked to cognitive dysfunction in Alzheimer disease (AD). As measured by media lactate dehydrogenase levels, and staining with propidium iodide, acute exposure to low micromolar concentrations of the Abeta1-42 oligomer significantly induced cell death. This was accompanied by activation of the ERK1/2 signal transduction pathway in rat organotypic hippocampal slices. Notably, this resulted in caspase-3 activation by a process that led to proteolytic cleavage of Tau, which was recently confirmed to occur in AD brains. Tau cleavage likely occurred in the absence of overt synaptic loss, as suggested by the preserved levels of synaptophysin, a presynaptic marker. Moreover, among the pharmacological agents tested to inhibit several kinase cascades, only the ERK inhibitor significantly attenuated Abeta1-42 oligomer-induced toxicity concomitant with the reduction of activation of ERK1/2 and caspase-3 to a lesser extent. Importantly, the caspase-3 inhibitor also decreased Abeta oligomer-induced cell death, with no appreciable effect on the ERK signaling pathway, although such treatment was effective in reducing caspase-3 activation and Tau cleavage. Therefore, these results suggest that local targeting of the ERK1/2 signaling pathway to reduce Tau cleavage, as occurs with the inhibition of caspase-3 activation, may modulate the neurotoxic effects of soluble Abeta oligomer in the hippocampus and provide the rationale for symptomatic treatment of AD.
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Affiliation(s)
- Young Hae Chong
- Department of Microbiology, College of Medicine, Division of Molecular Biology and Neuroscience, Ewha Medical Research Institute, Ewha Womans University, Yangcheonku, Seoul, 158-710, Korea.
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26
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Wang Q, Yu S, Simonyi A, Sun GY, Sun AY. Kainic acid-mediated excitotoxicity as a model for neurodegeneration. Mol Neurobiol 2006; 31:3-16. [PMID: 15953808 DOI: 10.1385/mn:31:1-3:003] [Citation(s) in RCA: 268] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Accepted: 11/15/2004] [Indexed: 02/06/2023]
Abstract
Neuronal excitation involving the excitatory glutamate receptors is recognized as an important underlying mechanism in neurodegenerative disorders. Excitation resulting from stimulation of the ionotropic glutamate receptors is known to cause the increase in intracellular calcium and trigger calcium-dependent pathways that lead to neuronal apoptosis. Kainic acid (KA) is an agonist for a subtype of ionotropic glutamate receptor, and administration of KA has been shown to increase production of reactive oxygen species, mitochondrial dysfunction, and apoptosis in neurons in many regions of the brain, particularly in the hippocampal subregions of CA1 and CA3, and in the hilus of dentate gyrus (DG). Systemic injection of KA to rats also results in activation of glial cells and inflammatory responses typically found in neurodegenerative diseases. KA-induced selective vulnerability in the hippocampal neurons is related to the distribution and selective susceptibility of the AMPA/kainate receptors in the brain. Recent studies have demonstrated ability of KA to alter a number of intracellular activities, including accumulation of lipofuscin-like substances, induction of complement proteins, processing of amyloid precursor protein, and alteration of tau protein expression. These studies suggest that KA-induced excitotoxicity can be used as a model for elucidating mechanisms underlying oxidative stress and inflammation in neurodegenerative diseases. The focus of this review is to summarize studies demonstrating KA-induced excitotoxicity in the central nervous system and possible intervention by anti-oxidants.
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Affiliation(s)
- Qun Wang
- Department of Medical Pharmacology, University of Missouri School of Medicine, Columbia, MO, USA
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27
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Mielke JG, Comas T, Woulfe J, Monette R, Chakravarthy B, Mealing GAR. Cytoskeletal, synaptic, and nuclear protein changes associated with rat interface organotypic hippocampal slice culture development. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2005; 160:275-86. [PMID: 16271399 DOI: 10.1016/j.devbrainres.2005.09.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 09/27/2005] [Accepted: 09/29/2005] [Indexed: 11/27/2022]
Abstract
Although organotypic hippocampal slice cultures (OHSCs) are used to study function within the hippocampus, the effect of maintenance in vitro upon protein expression is not fully understood. Therefore, we examined developmental changes in cultures prepared from P8 rats and maintained on porous membranes between medium and atmosphere. Between 7 and 28 days following explantation, altered hippocampal morphology could not be detected despite a significant decrease in both MAP-2c and a mid-range tau isoform by 21 DIV. During the same period, lower GFAP expression was observed, and GFAP labeling suggested a migration of astrocytes to the slice-atmosphere interface. In contrast, levels of the synaptic proteins synaptophysin and PSD-95 were significantly increased, but GAP-43 was not. The preservation of myelinated axons and synapses, along with glial and endothelial cells, was confirmed by ultrastructural analysis. Furthermore, intranuclear inclusion bodies, which are associated with normal aging in vivo, were detected in the CA1 pyramidal layer in cultures older than 14 DIV. When OHSCs were maintained for approximately 3, 4, and 10 weeks, a rise and then fall in the expression of synaptophysin and, especially, PSD-95 were found, and the biphasic trend paralleled by significant changes in Schaffer collateral-evoked excitatory post-synaptic potentials from CA1 neurons. Our data not only describe changes in cytoskeletal, synaptic, and nuclear proteins related to the maintenance of interface OHSCs, but also emphasize the potential of the model for the study of age-related phenomena within the hippocampus.
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Affiliation(s)
- John G Mielke
- Neurobiology Program, Institute for Biological Sciences, National Research Council of Canada, 1200 Montreal Rd., Building M-54, Ottawa, Ontario, Canada K1A 0R6.
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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.
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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
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