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Li Z, Wu H, Luo Y, Tan X. Correlation of serum complement factor 5a level with inflammatory response and cognitive function in patients with Alzheimer's disease of different severity. BMC Neurol 2023; 23:319. [PMID: 37679689 PMCID: PMC10483705 DOI: 10.1186/s12883-023-03256-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 05/22/2023] [Indexed: 09/09/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a common cause of dementia. Serum complement factor 5a (C5a) is exceedingly implicated in AD. We explored the role of C5a levels in AD patients of different severity. METHODS Mild, moderate, and severe AD patients, and healthy controls were included. C5a and pro-inflammatory factor (TNF-α, IL-1β, IL-6, CRP) levels were assessed by ELISA, and cognitive function was evaluated by Mini-Mental state examination (MMSE) score. The correlations between C5a, inflammatory factor levels, MMSE score, and plasma Aβ42/Aβ40 ratio were analyzed by Pearson tests. Independent risk factors for AD aggravation were assessed by logistic multivariate regression analysis. According to the cut-off value of receiver operating characteristic (ROC) curve analysis of C5a level, AD patients were assigned into low/high expression groups, and severe AD incidence was compared. Severe AD cumulative incidence was analyzed by Kaplan-Meier curve. RESULTS Serum C5a, TNF-α, IL-1β, IL-6 and CRP levels were raised, and MMSE score was lowered in AD. Serum C5a, TNF-α, IL-1β, IL-6 and CRP levels in severe AD patients were higher than those in mild/moderate AD patients, but there were no significant differences in these cytokines between moderate and mild AD groups. The MMSE score of severe AD patients was lower than that of mild/moderate AD patients. Serum C5a level was positively correlated with serum TNF-α, IL-1β, IL-6, and CRP levels, and negatively correlated with MMSE score, with no obvious correlation with plasma Aβ42/Aβ40 ratio. Serum C5a level was one of the independent risk factors for AD aggravation. The occurrence of severe AD might be related to an increase in serum C5a level. CONCLUSION Serum C5a level increased with AD severity, and its expression was positively correlated with serum pro-inflammatory factor levels, and negatively correlated with cognitive function.
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Affiliation(s)
- Zhilian Li
- Department of Neurology, The First People´s Hospital of Jingzhou City, No.8 HangKong Road, Shashi District, 434100, Jingzhou City, Hubei Province, P.R. China
| | - Huifang Wu
- Yangtze University, 434023, Jingzhou City, Hubei Province, P.R. China.
| | - Yi Luo
- Department of Neurology, The First People´s Hospital of Jingzhou City, No.8 HangKong Road, Shashi District, 434100, Jingzhou City, Hubei Province, P.R. China
| | - Xianpei Tan
- Department of Neurology, The First People´s Hospital of Jingzhou City, No.8 HangKong Road, Shashi District, 434100, Jingzhou City, Hubei Province, P.R. China
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2
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Pisani F, Pisani V, Arcangeli F, Harding A, Singhrao SK. Treponema denticola Has the Potential to Cause Neurodegeneration in the Midbrain via the Periodontal Route of Infection-Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6049. [PMID: 37297653 PMCID: PMC10252855 DOI: 10.3390/ijerph20116049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/30/2023] [Accepted: 05/29/2023] [Indexed: 06/12/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease and the most common example of dementia. The neuropathological features of AD are the abnormal deposition of extracellular amyloid-β (Aβ) and intraneuronal neurofibrillary tangles with hyperphosphorylated tau protein. It is recognized that AD starts in the frontal cerebral cortex, and then it progresses to the entorhinal cortex, the hippocampus, and the rest of the brain. However, some studies on animals suggest that AD could also progress in the reverse order starting from the midbrain and then spreading to the frontal cortex. Spirochetes are neurotrophic: From a peripheral route of infection, they can reach the brain via the midbrain. Their direct and indirect effect via the interaction of their virulence factors and the microglia potentially leads to the host peripheral nerve, the midbrain (especially the locus coeruleus), and cortical damage. On this basis, this review aims to discuss the hypothesis of the ability of Treponema denticola to damage the peripheral axons in the periodontal ligament, to evade the complemental pathway and microglial immune response, to determine the cytoskeletal impairment and therefore causing the axonal transport disruption, an altered mitochondrial migration and the consequent neuronal apoptosis. Further insights about the central neurodegeneration mechanism and Treponema denticola's resistance to the immune response when aggregated in biofilm and its quorum sensing are suggested as a pathogenetic model for the advanced stages of AD.
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Affiliation(s)
- Flavio Pisani
- Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston PR1 2HE, UK
| | - Valerio Pisani
- IRCCS, “Santa Lucia” Foundation, Neurology and Neurorehabilitation Unit, Via Ardeatina, 306, 00179 Rome, Italy
| | - Francesca Arcangeli
- Azienda Sanitaria Locale ASLRM1, Nuovo Regina Margherita Hospital, Geriatric Department, Advanced Centre for Dementia and Cognitive Disorders, Via Emilio Morosini, 30, 00153 Rome, Italy
| | - Alice Harding
- Dementia and Neurodegenerative Disease Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston PR1 2HE, UK
| | - Simarjit Kaur Singhrao
- Dementia and Neurodegenerative Disease Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston PR1 2HE, UK
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3
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Loeffler DA. Modifiable, Non-Modifiable, and Clinical Factors Associated with Progression of Alzheimer's Disease. J Alzheimers Dis 2021; 80:1-27. [PMID: 33459643 DOI: 10.3233/jad-201182] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
There is an extensive literature relating to factors associated with the development of Alzheimer's disease (AD), but less is known about factors which may contribute to its progression. This review examined the literature with regard to 15 factors which were suggested by PubMed search to be positively associated with the cognitive and/or neuropathological progression of AD. The factors were grouped as potentially modifiable (vascular risk factors, comorbidities, malnutrition, educational level, inflammation, and oxidative stress), non-modifiable (age at clinical onset, family history of dementia, gender, Apolipoprotein E ɛ4, genetic variants, and altered gene regulation), and clinical (baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs). Although conflicting results were found for the majority of factors, a positive association was found in nearly all studies which investigated the relationship of six factors to AD progression: malnutrition, genetic variants, altered gene regulation, baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs. Whether these or other factors which have been suggested to be associated with AD progression actually influence the rate of decline of AD patients is unclear. Therapeutic approaches which include addressing of modifiable factors associated with AD progression should be considered.
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Affiliation(s)
- David A Loeffler
- Beaumont Research Institute, Department of Neurology, Beaumont Health, Royal Oak, MI, USA
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4
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Ma Y, Liu Y, Zhang Z, Yang GY. Significance of Complement System in Ischemic Stroke: A Comprehensive Review. Aging Dis 2019; 10:429-462. [PMID: 31011487 PMCID: PMC6457046 DOI: 10.14336/ad.2019.0119] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/19/2019] [Indexed: 12/14/2022] Open
Abstract
The complement system is an essential part of innate immunity, typically conferring protection via eliminating pathogens and accumulating debris. However, the defensive function of the complement system can exacerbate immune, inflammatory, and degenerative responses in various pathological conditions. Cumulative evidence indicates that the complement system plays a critical role in the pathogenesis of ischemic brain injury, as the depletion of certain complement components or the inhibition of complement activation could reduce ischemic brain injury. Although multiple candidates modulating or inhibiting complement activation show massive potential for the treatment of ischemic stroke, the clinical availability of complement inhibitors remains limited. The complement system is also involved in neural plasticity and neurogenesis during cerebral ischemia. Thus, unexpected side effects could be induced if the systemic complement system is inhibited. In this review, we highlighted the recent concepts and discoveries of the roles of different kinds of complement components, such as C3a, C5a, and their receptors, in both normal brain physiology and the pathophysiology of brain ischemia. In addition, we comprehensively reviewed the current development of complement-targeted therapy for ischemic stroke and discussed the challenges of bringing these therapies into the clinic. The design of future experiments was also discussed to better characterize the role of complement in both tissue injury and recovery after cerebral ischemia. More studies are needed to elucidate the molecular and cellular mechanisms of how complement components exert their functions in different stages of ischemic stroke to optimize the intervention of targeting the complement system.
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Affiliation(s)
- Yuanyuan Ma
- 1Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,2Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yanqun Liu
- 3Department of Neurology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Zhijun Zhang
- 2Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Guo-Yuan Yang
- 1Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,2Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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5
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Guidolin D, Fede C, Tortorella C. Nerve cells developmental processes and the dynamic role of cytokine signaling. Int J Dev Neurosci 2018; 77:3-17. [PMID: 30465872 DOI: 10.1016/j.ijdevneu.2018.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/13/2018] [Accepted: 11/14/2018] [Indexed: 12/14/2022] Open
Abstract
The stunning diversity of neurons and glial cells makes possible the higher functions of the central nervous system (CNS), allowing the organism to sense, interpret and respond appropriately to the external environment. This cellular diversity derives from a single primary progenitor cell type initiating lineage leading to the formation of both differentiated neurons and glial cells. The processes governing the differentiation of the progenitor pool of cells into mature nerve cells will be here briefly reviewed. They involve morphological transformations, specialized modes of cell division, migration, and controlled cell death, and are regulated through cell-cell interactions and cues provided by the extracellular matrix, as well as by humoral factors from the cerebrospinal fluid and the blood system. In this respect, a quite large body of studies have been focused on cytokines, proteins representing the main signaling network that coordinates immune defense and the maintenance of homeostasis. At the same time, they are deeply involved in CNS development as regulatory factors. This dual role in the nervous system appears of particular relevance for CNS pathology, since cytokine dysregulation (occurring as a consequence of maternal infection, exposure to environmental factors or prenatal hypoxia) can profoundly impact on neurodevelopment and likely influence the response of the adult tissue during neuroinflammatory events.
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Affiliation(s)
- Diego Guidolin
- Department of Neuroscience, University of Padova, via Gabelli 65, I-35121, Padova, Italy
| | - Caterina Fede
- Department of Neuroscience, University of Padova, via Gabelli 65, I-35121, Padova, Italy
| | - Cinzia Tortorella
- Department of Neuroscience, University of Padova, via Gabelli 65, I-35121, Padova, Italy
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6
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Linetsky M, Bondelid KS, Losovskiy S, Gabyak V, Rullo MJ, Stiadle TI, Munjapara V, Saxena P, Ma D, Cheng YS, Howes AM, Udeigwe E, Salomon RG. 4-Hydroxy-7-oxo-5-heptenoic Acid Lactone Is a Potent Inducer of the Complement Pathway in Human Retinal Pigmented Epithelial Cells. Chem Res Toxicol 2018; 31:666-679. [PMID: 29883119 DOI: 10.1021/acs.chemrestox.8b00028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We previously discovered that oxidative cleavage of docosahexaenoate (DHA), which is especially abundant in the retinal photoreceptor rod outer segments and retinal pigmented endothelial (RPE) cells, generates 4-hydroxy-7-oxo-5-heptenoate (HOHA) lactone, and that HOHA lactone can enter RPE cells that metabolize it through conjugation with glutathione (GSH). The consequent depletion of GSH results in oxidative stress. We now find that HOHA lactone induces upregulation of the antioxidant transcription factor Nrf2 in ARPE-19 cells. This leads to expression of GCLM, HO1, and NQO1, three known Nrf2-responsive antioxidant genes. Besides this protective response, HOHA lactone also triggers a countervailing inflammatory activation of innate immunity. Evidence for a contribution of the complement pathway to age-related macular degeneration (AMD) pathology includes the presence of complement proteins in drusen and Bruch's membrane from AMD donor eyes, and the identification of genetic susceptibility loci for AMD in the complement pathway. In eye tissues from a mouse model of AMD, accumulation of complement protein in Bruch's membrane below the RPE suggested that the complement pathway targets this interface, where lesions occur in the RPE and photoreceptor rod outer segments. In animal models of AMD, intravenous injection of NaIO3 to induce oxidative injury selectively destroys the RPE and causes secretion of factor C3 from the RPE into areas directly adjacent to sites of RPE damage. However, a molecular-level link between oxidative injury and complement activation remained elusive. We now find that sub-micromolar concentrations of HOHA lactone foster expression of C3, CFB, and C5 in ARPE-19 cells and induce a countervailing upregulation of CD55, an inhibitor of C3 convertase production and complement cascade amplification. Ultimately, HOHA lactone causes membrane attack complex formation on the plasma membrane. Thus, HOHA lactone provides a molecular-level connection between free-radical-induced oxidative cleavage of DHA and activation of the complement pathway in AMD pathology.
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Affiliation(s)
- Mikhail Linetsky
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Karina S Bondelid
- Department of Biochemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Sofiya Losovskiy
- Department of Chemistry , Cleveland State University , Cleveland , Ohio 44115 , United States
| | - Vadym Gabyak
- Department of Biological, Geological, and Environmental Sciences , Cleveland State University , Cleveland , Ohio 44115 , United States
| | - Mario J Rullo
- Department of Biochemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Thomas I Stiadle
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Vasu Munjapara
- Department of Biochemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Priyali Saxena
- Department of Biochemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Duoming Ma
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Yu-Shiuan Cheng
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Andrew M Howes
- Department of Biochemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Emeka Udeigwe
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Robert G Salomon
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States.,Department of Ophthalmology & Visual Sciences , Case Western Reserve University , Cleveland , Ohio 44106 , United States
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7
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Bedoui Y, Neal JW, Gasque P. The Neuro-Immune-Regulators (NIREGs) Promote Tissue Resilience; a Vital Component of the Host's Defense Strategy against Neuroinflammation. J Neuroimmune Pharmacol 2018; 13:309-329. [PMID: 29909495 DOI: 10.1007/s11481-018-9793-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 05/24/2018] [Indexed: 01/29/2023]
Abstract
An effective protective inflammatory response in the brain is crucial for the clearance of pathogens (e.g. microbes, amyloid fibrils, prionSC) and should be closely regulated. However, the CNS seems to have limited tissue resilience to withstand the detrimental effects of uncontrolled inflammation compromising functional recovery and tissue repair. Newly described neuro-immune-regulators (NIREGs) are functionally related proteins regulating the severity and duration of the host inflammatory response. NIREGs such as CD200, CD47 and CX3CL1 are vital for increasing tissue resilience and are constitutively expressed by neurons. The interaction with co-receptors (CD200R, CD172a, CX3CR1) will maintain microglia in the resting phenotype, directing aggressive microglia phenotype and limiting bystander injuries. Neurons can also express many of the complement NIREGs (CD55, CD46, CD59 and factor H). Neurons and glia also express suppressor of cytokine signaling proteins (SOCS) down regulating janus kinase-signal transducer and activator of transcription (JAK/STAT) pathway and to lead to the polarization of microglia towards anti-inflammatory phenotype. Other NIREGs such as serine protease inhibitors (serpins) and thrombomodulin (CD141) inhibit neurotoxic systemic coagulation proteins such as thrombin. The unfolded protein response (UPR) detects misfolded proteins and other stressors to prevent irreversible cell injury. Microglial pattern recognition receptors (PRR) (TREM-2, CR3, FcγR) are important to clear apoptotic cells and cellular debris but in non-phlogystic manner through inhibitory signaling pathways. The TYRO3, Axl, Mer (TAM) tyrosine receptor kinases activated by Gas 6 and PROS1 regulate inflammation by inhibiting Toll like receptors (TLR) /JAK-STAT activation and contribute to NIREG's functions.
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Affiliation(s)
- Yosra Bedoui
- Université de la Réunion, CRNS 9192, INSERM U1187, IRD249, Unité Mixte Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Plateforme Technologique CYROI, Saint -Clotilde, La Réunion, France
| | - Jim W Neal
- Infection and Immunity, Cardiff University, Henry Wellcome Building, Cardiff, CF14 4XN, UK.
| | - Philippe Gasque
- Laboratoire de biologie, secteur laboratoire d'immunologie Clinique et expérimentale ZOI, LICE-OI, CHU Felix Guyon Bellepierre, St Denis, La Réunion, France.
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8
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Morgan BP. Complement in the pathogenesis of Alzheimer's disease. Semin Immunopathol 2018; 40:113-124. [PMID: 29134267 PMCID: PMC5794825 DOI: 10.1007/s00281-017-0662-9] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/01/2017] [Indexed: 12/19/2022]
Abstract
The emergence of complement as an important player in normal brain development and pathological remodelling has come as a major surprise to most scientists working in neuroscience and almost all those working in complement. That a system, evolved to protect the host against infection, should have these unanticipated roles has forced a rethink about what complement might be doing in the brain in health and disease, where it is coming from, and whether we can, or indeed should, manipulate complement in the brain to improve function or restore homeostasis. Complement has been implicated in diverse neurological and neuropsychiatric diseases well reviewed elsewhere, from depression through epilepsy to demyelination and dementia, in most complement drives inflammation to exacerbate the disease. Here, I will focus on just one disease, the most common cause of dementia, Alzheimer's disease. I will briefly review the current understanding of what complement does in the normal brain, noting, in particular, the many gaps in understanding, then describe how complement may influence the genesis and progression of pathology in Alzheimer's disease. Finally, I will discuss the problems and pitfalls of therapeutic inhibition of complement in the Alzheimer brain.
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Affiliation(s)
- B Paul Morgan
- Systems Immunity Research Institute and Dementia Research Institute Cardiff, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK.
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9
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Evzelman MA, Orlova AD, Lashkhia YB, Mityaeva EV, Kamchatnov PR. [Prognostic markers of ischemic stroke outcome]. Zh Nevrol Psikhiatr Im S S Korsakova 2018; 118:50-53. [PMID: 30830117 DOI: 10.17116/jnevro201811812250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIM To determine the clinical significance of peripheral blood leukocyte indices in predicting the outcome of ischemic stroke (IS). MATERIAL AND METHODS Forty-five case histories of patients with IS were retrospectively analyzed (25 with a favorable, 20 with a fatal outcome of the disease). Index of blood leukocyte shift (IBLS) and index of the ratio of blood leukocytes and ESR (BLESR), which were calculated based on the results of the General analysis of peripheral blood collected during hospitalization, were chosen as markers of the severity of the condition and prognosis of the disease. The severity of neurological deficit was assessed on the NIHSS scale. RESULTS In patients with a favorable IS outcome, IBLS was 3.85±0.67, BLESR 2.47±1.22; the correlation coefficient of the severity of neurological deficit and IBLS with a favorable outcome was 0.21, which corresponds to a weak positive Cheddock's association. In patients with unfavorable outcome, ISLC was 7.73±2.72, BLESR 3,39±1,54; correlation coefficient 0.55 (moderate Cheddock's association). CONCLUSION The probability of death increases at higher values of IBLS and BLESR. Average values of the indices in the unfavorable outcome exceed approximately 1.5-2 times those in the favorable outcome. Regression analysis between ISC and the severity of neurological deficits in case of death showed a moderate correlation: the higher the ISC and NIHSS values, the greater the probability of death. The results can help in IS outcome prognosis and the choice of correct tactics of treatment of the patient in the acute stage.
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Affiliation(s)
| | - A D Orlova
- Turgenev Orel State University, Orel, Russia
| | | | | | - P R Kamchatnov
- Pirogov Russian National Research Medical University, Moscow, Russia
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10
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Manousopoulou A, Gatherer M, Smith C, Nicoll JAR, Woelk CH, Johnson M, Kalaria R, Attems J, Garbis SD, Carare RO. Systems proteomic analysis reveals that clusterin and tissue inhibitor of metalloproteinases 3 increase in leptomeningeal arteries affected by cerebral amyloid angiopathy. Neuropathol Appl Neurobiol 2016; 43:492-504. [PMID: 27543695 PMCID: PMC5638106 DOI: 10.1111/nan.12342] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 08/16/2016] [Accepted: 08/16/2016] [Indexed: 01/06/2023]
Abstract
Aims Amyloid beta (Aβ) accumulation in the walls of leptomeningeal arteries as cerebral amyloid angiopathy (CAA) is a major feature of Alzheimer's disease. In this study, we used global quantitative proteomic analysis to examine the hypothesis that the leptomeningeal arteries derived from patients with CAA have a distinct endophenotypic profile compared to those from young and elderly controls. Methods Freshly dissected leptomeningeal arteries from the Newcastle Brain Tissue Resource and Edinburgh Sudden Death Brain Bank from seven elderly (82.9 ± 7.5 years) females with severe capillary and arterial CAA, as well as seven elderly (88.3 ± 8.6 years) and five young (45.4 ± 3.9 years) females without CAA were used in this study. Arteries from four patients with CAA, two young and two elderly controls were individually analysed using quantitative proteomics. Key proteomic findings were then validated using immunohistochemistry. Results Bioinformatics interpretation of the results showed a significant enrichment of the immune response/classical complement and extracellular matrix remodelling pathways (P < 0.05) in arteries affected by CAA vs. those from young and elderly controls. Clusterin (apolipoprotein J) and tissue inhibitor of metalloproteinases‐3 (TIMP3), validated using immunohistochemistry, were shown to co‐localize with Aβ and to be up‐regulated in leptomeningeal arteries from CAA patients compared to young and elderly controls. Conclusions Global proteomic profiling of brain leptomeningeal arteries revealed that clusterin and TIMP3 increase in leptomeningeal arteries affected by CAA. We propose that clusterin and TIMP3 could facilitate perivascular clearance and may serve as novel candidate therapeutic targets for CAA.
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Affiliation(s)
- A Manousopoulou
- Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.,Institute for Life Sciences, University of Southampton, Southampton, UK
| | - M Gatherer
- Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK
| | - C Smith
- Pathology Department, University of Edinburgh, Edinburgh, UK
| | - J A R Nicoll
- Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK
| | - C H Woelk
- Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK
| | - M Johnson
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - R Kalaria
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - J Attems
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - S D Garbis
- Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK.,Institute for Life Sciences, University of Southampton, Southampton, UK.,Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK
| | - R O Carare
- Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK
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11
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Abstract
The complement system is a major component of innate immunity and a potent driver of inflammation. It has key roles in host defense against pathogens but can also contribute to pathology by driving inflammation and cell damage in diverse diseases. Complement has emerged as an important factor in the pathogenesis of numerous diseases of the CNS and PNS, including infectious, autoimmune and degenerative disorders, and is increasingly implicated in neuropsychiatric disease. Establishing the roles and relevance of complement in disease pathogenesis has become ever more important in recent years as new drugs targeting the complement system have reached the clinic, and the potential for using complement analytes as disease biomarkers has been recognized. In this brief review, the author summarizes the evidence implicating complement in these diseases and outlines ways in which this new understanding can be used to aid diagnosis and improve outcome.
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Affiliation(s)
- Bryan Paul Morgan
- a Institute of Infection and Immunity, School of Medicine, Cardiff University, Henry Wellcome Building, Heath Park, Cardiff CF144XN, UK
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12
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Williams PA, Tribble JR, Pepper KW, Cross SD, Morgan BP, Morgan JE, John SWM, Howell GR. Inhibition of the classical pathway of the complement cascade prevents early dendritic and synaptic degeneration in glaucoma. Mol Neurodegener 2016; 11:26. [PMID: 27048300 PMCID: PMC4822272 DOI: 10.1186/s13024-016-0091-6] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 03/23/2016] [Indexed: 12/13/2022] Open
Abstract
Background Glaucoma is a complex, multifactorial disease characterised by the loss of retinal ganglion cells and their axons leading to a decrease in visual function. The earliest events that damage retinal ganglion cells in glaucoma are currently unknown. Retinal ganglion cell death appears to be compartmentalised, with soma, dendrite and axon changes potentially occurring through different mechanisms. There is mounting evidence from other neurodegenerative diseases suggesting that neuronal dendrites undergo a prolonged period of atrophy, including the pruning of synapses, prior to cell loss. In addition, recent evidence has shown the role of the complement cascade in synaptic pruning in glaucoma and other diseases. Results Using a genetic (DBA/2J mouse) and an inducible (rat microbead) model of glaucoma we first demonstrate that there is loss of retinal ganglion cell synapses and dendrites at time points that precede axon or soma loss. We next determine the role of complement component 1 (C1) in early synaptic loss and dendritic atrophy during glaucoma. Using a genetic knockout of C1qa (D2.C1qa-/- mouse) or pharmacological inhibition of C1 (in the rat bead model) we show that inhibition of C1 is sufficient to preserve dendritic and synaptic architecture. Conclusions This study further supports assessing the potential for complement-modulating therapeutics for the prevention of retinal ganglion cell degeneration in glaucoma.
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Affiliation(s)
| | - James R Tribble
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | | | - Stephen D Cross
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - B Paul Morgan
- Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Simon W M John
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA. .,Department of Ophthalmology, Tufts University of Medicine, Boston, MA, 02111, USA. .,The Howard Hughes Medical Institute, Bar Harbor, ME, 04609, USA.
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA. .,Graduate Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA, USA.
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García-Marqués F, Trevisan-Herraz M, Martínez-Martínez S, Camafeita E, Jorge I, Lopez JA, Méndez-Barbero N, Méndez-Ferrer S, Del Pozo MA, Ibáñez B, Andrés V, Sánchez-Madrid F, Redondo JM, Bonzon-Kulichenko E, Vázquez J. A Novel Systems-Biology Algorithm for the Analysis of Coordinated Protein Responses Using Quantitative Proteomics. Mol Cell Proteomics 2016; 15:1740-60. [PMID: 26893027 DOI: 10.1074/mcp.m115.055905] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Indexed: 11/06/2022] Open
Abstract
The coordinated behavior of proteins is central to systems biology. However, the underlying mechanisms are poorly known and methods to analyze coordination by conventional quantitative proteomics are still lacking. We present the Systems Biology Triangle (SBT), a new algorithm that allows the study of protein coordination by pairwise quantitative proteomics. The Systems Biology Triangle detected statistically significant coordination in diverse biological models of very different nature and subjected to different kinds of perturbations. The Systems Biology Triangle also revealed with unprecedented molecular detail an array of coordinated, early protein responses in vascular smooth muscle cells treated at different times with angiotensin-II. These responses included activation of protein synthesis, folding, turnover, and muscle contraction - consistent with a differentiated phenotype-as well as the induction of migration and the repression of cell proliferation and secretion. Remarkably, the majority of the altered functional categories were protein complexes, interaction networks, or metabolic pathways. These changes could not be detected by other algorithms widely used by the proteomics community, and the vast majority of proteins involved have not been described before to be regulated by AngII. The unique capabilities of The Systems Biology Triangle to detect functional protein alterations produced by the coordinated action of proteins in pairwise quantitative proteomics experiments make this algorithm an attractive choice for the biological interpretation of results on a routine basis.
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Affiliation(s)
- Fernando García-Marqués
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Marco Trevisan-Herraz
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Sara Martínez-Martínez
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Emilio Camafeita
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Inmaculada Jorge
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Juan Antonio Lopez
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Nerea Méndez-Barbero
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Simón Méndez-Ferrer
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Miguel Angel Del Pozo
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Borja Ibáñez
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Vicente Andrés
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | | | - Juan Miguel Redondo
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Elena Bonzon-Kulichenko
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Jesús Vázquez
- From the ‡Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
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Alawieh A, Elvington A, Zhu H, Yu J, Kindy MS, Atkinson C, Tomlinson S. Modulation of post-stroke degenerative and regenerative processes and subacute protection by site-targeted inhibition of the alternative pathway of complement. J Neuroinflammation 2015; 12:247. [PMID: 26714866 PMCID: PMC4696299 DOI: 10.1186/s12974-015-0464-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/20/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Complement promotes neuroinflammation and injury in models of stroke. However, complement is also being increasingly implicated in repair and regeneration after central nervous system (CNS) injury, and some complement deficiencies have been shown to provide acute, but not subacute, protection after murine stroke. Here, we investigate the dual role of complement in injury and repair after cerebral ischemia and reperfusion. METHODS We used complement-deficient mice and different complement inhibitors in a model of transient middle cerebral artery occlusion to investigate complement-dependent cellular and molecular changes that occur through the subacute phase after stroke. RESULTS C3 deficiency and site-targeted complement inhibition with either CR2-Crry (inhibits all pathways) or CR2-fH (inhibits alternative pathway) significantly reduced infarct size, reduced apoptotic cell death, and improved neurological deficit score in the acute phase after stroke. However, only in CR2-fH-treated mice was there sustained protection with no evolution of injury in the subacute phase. Whereas both inhibitors significantly reduced microglia/macrophage activation and astrogliosis in the subacute phase, only CR2-fH improved neurological deficit and locomotor function, maintained neurogenesis markers, enhanced neuronal migration, and increased VEGF expression. These findings in CR2-fH-treated mice correlated with improved performance in spatial learning and passive avoidance tasks. The complement anaphylatoxins have been implicated in repair and regenerative mechanisms after CNS injury, and in this context CR2-fH significantly reduced, but did not eliminate the generation of C5a within the brain, unlike CR2-Crry that completely blocked C5a generation. Gene expression profiling revealed that CR2-fH treatment downregulated genes associated with apoptosis, TGFβ signaling, and neutrophil activation, and decreased neutrophil infiltration was confirmed by immunohistochemistry. CR2-fH upregulated genes for neural growth factor and mediators of neurogenesis and neuronal migration. Live animal imaging demonstrated that following intravenous injection, CR2-fH targeted specifically to the post-ischemic brain, with a tissue half-life of 48.5 h. Finally, unlike C3 deficiency, targeted complement inhibition did not increase susceptibility to lethal post-stroke infection, an important consideration for stroke patients. CONCLUSIONS Ischemic brain tissue-targeted and selective inhibition of alternative complement pathway provide self-limiting inhibition of complement activation and reduces acute injury while maintaining complement-dependent recovery mechanisms into the subacute phase after stroke.
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Affiliation(s)
- Ali Alawieh
- Department of Microbiology and Immunology, Children's Research Institute, Medical University of South Carolina, 173 Ashley Avenue BSB 201, Charleston, SC, 29425, USA.
| | - Andrew Elvington
- Department of Microbiology and Immunology, Children's Research Institute, Medical University of South Carolina, 173 Ashley Avenue BSB 201, Charleston, SC, 29425, USA.
| | - Hong Zhu
- Department of Neuroscience, Neuroscience Institute, Medical University of South Carolina, Charleston, SC, USA.
| | - Jin Yu
- Department of Neuroscience, Neuroscience Institute, Medical University of South Carolina, Charleston, SC, USA.
| | - Mark S Kindy
- Department of Neuroscience, Neuroscience Institute, Medical University of South Carolina, Charleston, SC, USA. .,Ralph H. Johnson Veteran Affairs Medical Center, Charleston, SC, USA.
| | - Carl Atkinson
- Department of Microbiology and Immunology, Children's Research Institute, Medical University of South Carolina, 173 Ashley Avenue BSB 201, Charleston, SC, 29425, USA.
| | - Stephen Tomlinson
- Department of Microbiology and Immunology, Children's Research Institute, Medical University of South Carolina, 173 Ashley Avenue BSB 201, Charleston, SC, 29425, USA. .,Ralph H. Johnson Veteran Affairs Medical Center, Charleston, SC, USA.
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15
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Jackson HM, Onos KD, Pepper KW, Graham LC, Akeson EC, Byers C, Reinholdt LG, Frankel WN, Howell GR. DBA/2J genetic background exacerbates spontaneous lethal seizures but lessens amyloid deposition in a mouse model of Alzheimer's disease. PLoS One 2015; 10:e0125897. [PMID: 25933409 PMCID: PMC4416920 DOI: 10.1371/journal.pone.0125897] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/24/2015] [Indexed: 11/23/2022] Open
Abstract
Alzheimer’s disease (AD) is a leading cause of dementia in the elderly and is characterized by amyloid plaques, neurofibrillary tangles (NFTs) and neuronal dysfunction. Early onset AD (EOAD) is commonly caused by mutations in amyloid precursor protein (APP) or genes involved in the processing of APP including the presenilins (e.g. PSEN1 or PSEN2). In general, mouse models relevant to EOAD recapitulate amyloidosis, show only limited amounts of NFTs and neuronal cell dysfunction and low but significant levels of seizure susceptibility. To investigate the effect of genetic background on these phenotypes, we generated APPswe and PSEN1de9 transgenic mice on the seizure prone inbred strain background, DBA/2J. Previous studies show that the DBA/2J genetic background modifies plaque deposition in the presence of mutant APP but the impact of PSEN1de9 has not been tested. Our study shows that DBA/2J.APPswePSEN1de9 mice are significantly more prone to premature lethality, likely to due to lethal seizures, compared to B6.APPswePSEN1de9 mice—70% of DBA/2J.APPswePSEN1de9 mice die between 2-3 months of age. Of the DBA/2J.APPswePSEN1de9 mice that survived to 6 months of age, plaque deposition was greatly reduced compared to age-matched B6.APPswePSEN1de9 mice. The reduction in plaque deposition appears to be independent of microglia numbers, reactive astrocytosis and complement C5 activity.
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Affiliation(s)
| | - Kristen D. Onos
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | - Leah C. Graham
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- Sackler School of Medicine, Tufts University, Boston, United States of America
| | - Ellen C. Akeson
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Candice Byers
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | - Wayne N. Frankel
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Gareth R. Howell
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- Sackler School of Medicine, Tufts University, Boston, United States of America
- * E-mail:
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16
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Zheng M, Du H, Ni W, Koch LG, Britton SL, Keep RF, Xi G, Hua Y. Iron-induced necrotic brain cell death in rats with different aerobic capacity. Transl Stroke Res 2015; 6:215-23. [PMID: 25649272 DOI: 10.1007/s12975-015-0388-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/16/2015] [Accepted: 01/21/2015] [Indexed: 12/29/2022]
Abstract
Brain iron overload has a key role in brain injury after intracerebral hemorrhage (ICH). Our recent study demonstrated that ICH-induced brain injury was greater in low capacity runner (LCR) than in high capacity runner (HCR) rats. The present study examines whether iron-induced brain injury differs between LCRs and HCRs. Adult male LCR and HCR rats had an intracaudate injection of iron or saline. Rats were euthanized at 2 and at 24 h after T2 magnetic resonance imaging, and the brains were used for immunostaining and Western blotting. LCRs had more hemispheric swelling, T2 lesion volumes, blood-brain barrier disruption, and neuronal death at 24 h after iron injection (p < 0.05). Many propidium iodide (PI)-positive cells, indicative of necrotic cell death, were observed in the ipsilateral basal ganglia of both HCRs and LCRs at 2 h after iron injection. PI fluorescence intensity was higher in LCRs than in HCRs. In addition, membrane attack complex (MAC) expression was increased at 2 h after iron injection and was higher in LCRs than in HCRs. The PI-positive cells co-localized with MAC-positive cells in the ipsilateral basal ganglia. Iron induces more severe necrotic brain cell death, brain swelling, and blood-brain barrier disruption in LCR rats, which may be related with complement activation and MAC formation.
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Affiliation(s)
- Mingzhe Zheng
- Department of Neurosurgery, University of Michigan, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
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17
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Maurer AJ, Bonney PA, Toho LC, Glenn CA, Agarwal S, Battiste JD, Fung KM, Sughrue ME. Tumor necrosis-initiated complement activation stimulates proliferation of medulloblastoma cells. Inflamm Res 2015; 64:185-92. [PMID: 25603857 DOI: 10.1007/s00011-015-0796-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 01/08/2015] [Accepted: 01/12/2015] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE AND DESIGN We sought to determine the effect of necrosis-induced activation of the complement protein C3 in medulloblastoma. MATERIALS/METHODS Twelve medulloblastoma surgical specimens were evaluated for complement activation using immunohistochemistry, with H&E stains performed on adjacent tissue sections to determine the relationship of complement activation to necrotic tissue. Flow cytometry and Western blot were performed on three established medulloblastoma lines and one surgically-procured cell culture to determine expression of C3a receptor (C3aR) in medulloblastoma. In vitro proliferation of siRNA C3aR knockdown cells was compared to that of control siRNA cells with cell line Daoy. RESULTS Three surgical specimens were found to have necrosis on H&E sections. In each case, iC3b staining was identified on adjacent sections, limited to the necrotic region. In no case did necrosis occur without iC3b staining on adjacent sections. C3aR protein was demonstrated on both the three established cell lines and on the surgical culture. Proliferation assays of Daoy cells with siRNA knockdown vs. control siRNA revealed significantly reduced proliferation at 72 h (p = 0.001). CONCLUSIONS Necrosis is associated with complement activation in medulloblastoma. Medulloblastoma cells express C3aR, and siRNA-mediated knockdown of C3aR inhibits proliferation of these cells in vitro.
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Affiliation(s)
- Adrian J Maurer
- Department of Neurosurgery, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, 1000 N. Lincoln Blvd., Suite 4000, Oklahoma City, OK, 73104, USA,
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18
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Andreeva K, Zhang M, Fan W, Li X, Chen Y, Rebolledo-Mendez JD, Cooper NG. Time-dependent Gene Profiling Indicates the Presence of Different Phases for Ischemia/Reperfusion Injury in Retina. OPHTHALMOLOGY AND EYE DISEASES 2014; 6:43-54. [PMID: 25210480 PMCID: PMC4149383 DOI: 10.4137/oed.s17671] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/09/2014] [Accepted: 07/10/2014] [Indexed: 02/05/2023]
Abstract
Ischemia/reperfusion (IR) injury has been associated with several retinal pathologies, and a few genes/gene products have been linked to IR injury. However, the big picture of temporal changes, regarding the affected gene networks, pathways, and processes remains to be determined. The purpose of the present study was to investigate initial, intermediate, and later stages to characterize the etiology of IR injury in terms of the pathways affected over time. Analyses indicated that at the initial stage, 0-hour reperfusion following the ischemic period, the ischemia-associated genes were related to changes in metabolism. In contrast, at the 24-hour time point, the signature events in reperfusion injury include enhanced inflammatory and immune responses as well as cell death indicating that this would be a critical period for the development of any interventional therapeutic strategies. Genes in the signal transduction pathways, particularly transmitter receptors, are downregulated at this time. Activation of the complement system pathway clearly plays an important role in the later stages of reperfusion injury. Together, these results demonstrate that the etiology of injury related to IR is characterized by the appearance of specific patterns of gene expression at any given time point during retinal IR injury. These results indicate that evaluation of treatment strategies with respect to time is very critical.
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Affiliation(s)
- Kalina Andreeva
- Department of Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Meixia Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Wei Fan
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xiaohong Li
- Department of Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Yinlu Chen
- Department of Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Jovan D Rebolledo-Mendez
- Department of Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Nigel G Cooper
- Department of Anatomical Sciences and Neurobiology, University of Louisville, School of Medicine, Louisville, KY, USA
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Teixeira A, Cox RC, Egmond MR. Furan fatty acids efficiently rescue brain cells from cell death induced by oxidative stress. Food Funct 2014; 4:1209-15. [PMID: 23719714 DOI: 10.1039/c3fo60094g] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Treatment of rat brain C6 astroglioma cells with furan fatty acid F6 prior to exposure to hydrogen peroxide shows a strong protective effect of F6 against cell death resulting from oxidative stress. This protective effect is obtained only for F6 administered as a free fatty acid and with an intact furan ring. It is proposed that brain cells are rescued by F6 scavenging radicals elicited by lipid peroxidation within the cell membrane. Oxidative processes outside the cell membrane, such as protein carbonylation, are not affected by F6. Furan fatty acids such as those present in fish oils and marine organisms are likely beneficial for consumption in reducing the risk of diseases that have been implicated to arise from oxidative stress, such as Alzheimer's disease.
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Affiliation(s)
- Antoinette Teixeira
- Department of Membrane Biochemistry and Biophysics, Bijvoet Center, University of Utrecht, Padualaan 8, 3584CH Utrecht, The Netherlands
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20
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Abstract
Microglia are critical nervous system-specific cells influencing brain development, maintenance of the neural environment, response to injury, and repair. They contribute to neuronal proliferation and differentiation, pruning of dying neurons, synaptic remodeling and clearance of debris and aberrant proteins. Colonization of the brain occurs during gestation with an expansion following birth with localization stimulated by programmed neuronal death, synaptic pruning, and axonal degeneration. Changes in microglia phenotype relate to cellular processes including specific neurotransmitter, pattern recognition, or immune-related receptor activation. Upon activation, microglia cells have the capacity to release a number of substances, e.g., cytokines, chemokines, nitric oxide, and reactive oxygen species, which could be detrimental or beneficial to the surrounding cells. With aging, microglia shift their morphology and may display diminished capacity for normal functions related to migration, clearance, and the ability to shift from a pro-inflammatory to an anti-inflammatory state to regulate injury and repair. This shift in microglia potentially contributes to increased susceptibility and neurodegeneration as a function of age. In the current review, information is provided on the colonization of the brain by microglia, the expression of various pattern recognition receptors to regulate migration and phagocytosis, and the shift in related functions that occur in normal aging.
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Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, MD C1-04, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
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Rutar M, Natoli R, Albarracin R, Valter K, Provis J. 670-nm light treatment reduces complement propagation following retinal degeneration. J Neuroinflammation 2012. [PMID: 23181358 PMCID: PMC3517758 DOI: 10.1186/1742-2094-9-257] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
AIM Complement activation is associated with the pathogenesis of age-related macular degeneration (AMD). We aimed to investigate whether 670-nm light treatment reduces the propagation of complement in a light-induced model of atrophic AMD. METHODS Sprague-Dawley (SD) rats were pretreated with 9 J/cm(2) 670-nm light for 3 minutes daily over 5 days; other animals were sham treated. Animals were exposed to white light (1,000 lux) for 24 h, after which animals were kept in dim light (5 lux) for 7 days. Expression of complement genes was assessed by quantitative polymerase chain reaction (qPCR), and immunohistochemistry. Counts were made of C3-expressing monocytes/microglia using in situ hybridization. Photoreceptor death was also assessed using outer nuclear layer (ONL) thickness measurements, and oxidative stress using immunohistochemistry for 4-hydroxynonenal (4-HNE). RESULTS Following light damage, retinas pretreated with 670-nm light had reduced immunoreactivity for the oxidative damage maker 4-HNE in the ONL and outer segments, compared to controls. In conjunction, there was significant reduction in retinal expression of complement genes C1s, C2, C3, C4b, C3aR1, and C5r1 following 670 nm treatment. In situ hybridization, coupled with immunoreactivity for the marker ionized calcium binding adaptor molecule 1 (IBA1), revealed that C3 is expressed by infiltrating microglia/monocytes in subretinal space following light damage, which were significantly reduced in number after 670 nm treatment. Additionally, immunohistochemistry for C3 revealed a decrease in C3 deposition in the ONL following 670 nm treatment. CONCLUSIONS Our data indicate that 670-nm light pretreatment reduces lipid peroxidation and complement propagation in the degenerating retina. These findings have relevance to the cellular events of complement activation underling the pathogenesis of AMD, and highlight the potential of 670-nm light as a non-invasive anti-inflammatory therapy.
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Affiliation(s)
- Matt Rutar
- The John Curtin School of Medical Research, College of Medicine, Biology and Environment, The Australian National University, Building 131, Garran Rd, Canberra ACT 2601, Australia.
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Piesiewicz A, Kedzierska U, Podobas E, Adamska I, Zuzewicz K, Majewski P. Season-dependent Postembryonic Maturation of the Diurnal Rhythm of Melatonin Biosynthesis in the Chicken Pineal Gland. Chronobiol Int 2012; 29:1227-38. [DOI: 10.3109/07420528.2012.719964] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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The role of immune dysfunction in the pathophysiology of autism. Brain Behav Immun 2012; 26:383-92. [PMID: 21906670 PMCID: PMC3418145 DOI: 10.1016/j.bbi.2011.08.007] [Citation(s) in RCA: 427] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 08/19/2011] [Accepted: 08/22/2011] [Indexed: 12/22/2022] Open
Abstract
Autism spectrum disorders (ASD) are a complex group of neurodevelopmental disorders encompassing impairments in communication, social interactions and restricted stereotypical behaviors. Although a link between altered immune responses and ASD was first recognized nearly 40 years ago, only recently has new evidence started to shed light on the complex multifaceted relationship between immune dysfunction and behavior in ASD. Neurobiological research in ASD has highlighted pathways involved in neural development, synapse plasticity, structural brain abnormalities, cognition and behavior. At the same time, several lines of evidence point to altered immune dysfunction in ASD that directly impacts some or all these neurological processes. Extensive alterations in immune function have now been described in both children and adults with ASD, including ongoing inflammation in brain specimens, elevated pro-inflammatory cytokine profiles in the CSF and blood, increased presence of brain-specific auto-antibodies and altered immune cell function. Furthermore, these dysfunctional immune responses are associated with increased impairments in behaviors characteristic of core features of ASD, in particular, deficits in social interactions and communication. This accumulating evidence suggests that immune processes play a key role in the pathophysiology of ASD. This review will discuss the current state of our knowledge of immune dysfunction in ASD, how these findings may impact on underlying neuro-immune mechanisms and implicate potential areas where the manipulation of the immune response could have an impact on behavior and immunity in ASD.
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Harry GJ, Kraft AD. Microglia in the developing brain: a potential target with lifetime effects. Neurotoxicology 2012; 33:191-206. [PMID: 22322212 DOI: 10.1016/j.neuro.2012.01.012] [Citation(s) in RCA: 179] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/24/2012] [Accepted: 01/25/2012] [Indexed: 12/15/2022]
Abstract
Microglia are a heterogenous group of monocyte-derived cells serving multiple roles within the brain, many of which are associated with immune and macrophage like properties. These cells are known to serve a critical role during brain injury and to maintain homeostasis; yet, their defined roles during development have yet to be elucidated. Microglial actions appear to influence events associated with neuronal proliferation and differentiation during development, as well as, contribute to processes associated with the removal of dying neurons or cellular debris and management of synaptic connections. These long-lived cells display changes during injury and with aging that are critical to the maintenance of the neuronal environment over the lifespan of the organism. These processes may be altered by changes in the colonization of the brain or by inflammatory events during development. This review addresses the role of microglia during brain development, both structurally and functionally, as well as the inherent vulnerability of the developing nervous system. A framework is presented considering microglia as a critical nervous system-specific cell that can influence multiple aspects of brain development (e.g., vascularization, synaptogenesis, and myelination) and have a long term impact on the functional vulnerability of the nervous system to a subsequent insult, whether environmental, physical, age-related, or disease-related.
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Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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25
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Epigenetic mechanisms in Alzheimer's disease. Neurobiol Aging 2011; 32:1161-80. [PMID: 21482442 DOI: 10.1016/j.neurobiolaging.2010.08.017] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 07/20/2010] [Accepted: 08/07/2010] [Indexed: 12/20/2022]
Abstract
Epigenetic modifications help orchestrate sweeping developmental, aging, and disease-causing changes in phenotype by altering transcriptional activity in multiple genes spanning multiple biologic pathways. Although previous epigenetic research has focused primarily on dividing cells, particularly in cancer, recent studies have shown rapid, dynamic, and persistent epigenetic modifications in neurons that have significant neuroendocrine, neurophysiologic, and neurodegenerative consequences. Here, we provide a review of the major mechanisms for epigenetic modification and how they are reportedly altered in aging and Alzheimer's disease (AD). Because of their reach across the genome, epigenetic mechanisms may provide a unique integrative framework for the pathologic diversity and complexity of AD.
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26
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Pendyala G, Fox HS. Proteomic and metabolomic strategies to investigate HIV-associated neurocognitive disorders. Genome Med 2010; 2:22. [PMID: 20353544 PMCID: PMC2873800 DOI: 10.1186/gm143] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Diagnosing neurodegenerative diseases, monitoring their progression and assessing responses to treatments will all be aided by the identification of molecular markers of different stages of pathology. Protein biomarkers for HIV-associated neurocognitive disorders that have been discovered using proteomics include complement C3, soluble superoxide dismutase and a prostaglandin synthase. Metabolomics has not yet been widely used for biomarker discovery, but early work shows that it has great potential.
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Affiliation(s)
- Gurudutt Pendyala
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, 985800 Nebraska Medical Center, Omaha, NE 68198, USA.
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Hovhannisyan LP, Mkrtchyan GM, Sukiasian SH, Boyajyan AS. Alterations in the complement cascade in post-traumatic stress disorder. Allergy Asthma Clin Immunol 2010; 6:3. [PMID: 20298515 PMCID: PMC2834673 DOI: 10.1186/1710-1492-6-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 02/21/2010] [Indexed: 11/17/2022] Open
Abstract
Background In the present study we assessed the functional state of the major mediator of the immune response, the complement system, in post-traumatic stress disorder (PTSD). Methods Thirty one PTSD patients within 13 years from traumatic event and the same number of sex- and age-matched healthy volunteers were involved in this study. In the blood serum of the study subjects hemolytic activities of the classical and alternative complement pathways, as well as the activities of the individual complement components have been measured. Correlation analysis between all measured parameters was also performed. Results According to the results obtained PTSD is characterized by hyperactivation of the complement classical pathway, hypoactivation of the complement alternative pathway and overactivation of the terminal pathway. Conclusions The results obtained provide further evidence on the involvement of the inflammatory component in pathogenesis of PTSD.
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Abstract
Cytokines are pleotrophic proteins that coordinate the host response to infection as well as mediate normal, ongoing signaling between cells of nonimmune tissues, including the nervous system. As a consequence of this dual role, cytokines induced in response to maternal infection or prenatal hypoxia can profoundly impact fetal neurodevelopment. The neurodevelopmental roles of individual cytokine signaling pathways are being elucidated through gain- and loss-of-function studies in cell culture and model organisms. We review this work with a particular emphasis on studies where cytokines, their receptors, or components of their signaling pathways have been altered in vivo. The extensive and diverse requirements for properly regulated cytokine signaling during normal nervous system development revealed by these studies sets the foundation for ongoing and future work aimed at understanding how cytokines induced normally and pathologically during critical stages of fetal development alter nervous system function and behavior later in life.
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Affiliation(s)
- Benjamin E Deverman
- Division of Biology, California Institute of Technology, 1200 East California Boulevard M/C 216-76, Pasadena, CA 91125, USA
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Kolev MV, Tediose T, Sivasankar B, Harris CL, Thome J, Morgan BP, Donev RM. Upregulating CD59: a new strategy for protection of neurons from complement-mediated degeneration. THE PHARMACOGENOMICS JOURNAL 2009; 10:12-9. [DOI: 10.1038/tpj.2009.52] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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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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Pendyala G, Trauger SA, Kalisiak E, Ellis RJ, Siuzdak G, Fox HS. Cerebrospinal fluid proteomics reveals potential pathogenic changes in the brains of SIV-infected monkeys. J Proteome Res 2009; 8:2253-60. [PMID: 19281240 DOI: 10.1021/pr800854t] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The HIV-1-associated neurocognitive disorder occurs in approximately one-third of infected individuals. It has persisted in the current era of antiretroviral therapy, and its study is complicated by the lack of biomarkers for this condition. Since the cerebrospinal fluid is the most proximal biofluid to the site of pathology, we studied the cerebrospinal fluid in a nonhuman primate model for HIV-1-associated neurocognitive disorder. Here we present a simple and efficient liquid chromatography-coupled mass spectrometry-based proteomics approach that utilizes small amounts of cerebrospinal fluid. First, we demonstrate the validity of the methodology using human cerebrospinal fluid. Next, using the simian immunodeficiency virus-infected monkey model, we show its efficacy in identifying proteins such as alpha-1-antitrypsin, complement C3, hemopexin, IgM heavy chain, and plasminogen, whose increased expression is linked to disease. Finally, we find that the increase in cerebrospinal fluid proteins is linked to increased expression of their genes in the brain parenchyma, revealing that the cerebrospinal fluid alterations identified reflect changes in the brain itself and not merely leakage of the blood-brain or blood-cerebrospinal fluid barriers. This study reveals new central nervous system alterations in lentivirus-induced neurological disease, and this technique can be applied to other systems in which limited amounts of biofluids can be obtained.
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Affiliation(s)
- Gurudutt Pendyala
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska 68198-5800, USA
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Ingram G, Hakobyan S, Robertson NP, Morgan BP. Complement in multiple sclerosis: its role in disease and potential as a biomarker. Clin Exp Immunol 2008; 155:128-39. [PMID: 19040603 DOI: 10.1111/j.1365-2249.2008.03830.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system with a poorly defined and complex immunopathogenesis. Although initiated by reactive T cells, persistent inflammation is evident throughout the disease course. A contribution from complement has long been suspected, based on the results of pathological and functional studies which have demonstrated complement activation products in MS brain and biological fluids. However, the extent and nature of complement activation and its contribution to disease phenotype and long-term outcome remain unclear. Furthermore, functional polymorphisms in components and regulators of the complement system which cause dysregulation, and are known to contribute to other autoimmune inflammatory disorders, have not been investigated to date in MS in any detail. In this paper we review evidence from pathological, animal model and human functional and genetic studies, implicating activation of complement in MS. We also evaluate the potential of complement components and regulators and their polymorphic variants as biomarkers of disease, and suggest appropriate directions for future research.
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Affiliation(s)
- G Ingram
- Department of Neurosciences, Cardiff University, Heath Park, Cardiff, UK
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Hakobyan S, Harris CL, van den Berg CW, Fernandez-Alonso MC, de Jorge EG, de Cordoba SR, Rivas G, Mangione P, Pepys MB, Morgan BP. Complement factor H binds to denatured rather than to native pentameric C-reactive protein. J Biol Chem 2008; 283:30451-60. [PMID: 18786923 PMCID: PMC2662140 DOI: 10.1074/jbc.m803648200] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 08/20/2008] [Indexed: 11/06/2022] Open
Abstract
Binding of the complement regulatory protein, factor H, to C-reactive protein has been reported and implicated as the biological basis for association of the H402 polymorphic variant of factor H with macular degeneration. Published studies utilize solid-phase or fluid-phase binding assays to show that the factor H Y402 variant binds C-reactive protein more strongly than H402. Diminished binding of H402 variant to C-reactive protein in retinal drusen is posited to permit increased complement activation, driving inflammation and pathology. We used well validated native human C-reactive protein and pure factor H Y402H variants to test interactions. When factor H variants were incubated with C-reactive protein in the fluid phase at physiological concentrations, no association occurred. When C-reactive protein was immobilized on plastic, either non-specifically by adsorption in the presence of Ca(2+) to maintain its native fold and pentameric subunit assembly or by specific Ca(2+)-dependent binding to immobilized natural ligands, no specific binding of either factor H variant from the fluid phase was observed. In contrast, both factor H variants reproducibly bound to C-reactive protein immobilized in the absence of Ca(2+), conditions that destabilize the native fold and pentameric assembly. Both factor H variants strongly bound C-reactive protein that was denatured by heat treatment before immobilization, confirming interaction with denatured but not native C-reactive protein. We conclude that the reported binding of factor H to C-reactive protein results from denaturation of the C-reactive protein during immobilization. Differential binding to C-reactive protein, thus, does not explain association of the Y402H polymorphism with macular degeneration.
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Affiliation(s)
- Svetlana Hakobyan
- Department of Medical Biochemistry and Immunology and Pharmacology, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
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Kuehn MH, Kim CY, Jiang B, Dumitrescu AV, Kwon YH. Disruption of the complement cascade delays retinal ganglion cell death following retinal ischemia-reperfusion. Exp Eye Res 2008; 87:89-95. [PMID: 18572163 DOI: 10.1016/j.exer.2008.04.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 04/06/2008] [Accepted: 04/23/2008] [Indexed: 12/22/2022]
Abstract
Recent reports have indicated that components of the complement cascade are synthesized during the degeneration of retinal ganglion cells (RGC) in glaucoma. While complement deposition in the retina may simply serve to aid phagocytosis of damaged RGC, activation of the complement cascade can also contribute to neuronal loss in neurodegenerative diseases. This study was designed to determine if disruption of the complement cascade affects RGC survival in a murine model of retinal ischemia-reperfusion (I/R) injury. We induced retinal ischemia in the eyes of normal mice and mice with a targeted disruption of the complement component 3 (C3) gene. Tissue was harvested 7 and 21 days after induction of I/R and retinal complement synthesis was determined by quantitative PCR and immunohistochemical methods. RGC death and associated axon loss was evaluated through histological examination of the optic nerve and retina. Our data show that retinal I/R induces the expression and deposition of complement components. C3 deficient mice clearly exhibited reduced optic nerve damage and substantial preservation of RGC 1 week after I/R when compared to normal animals (p=0.005). Three weeks after the ischemic event C3 deficient mice retained more RGC cell bodies although the degree of optic nerve damage was similar between both groups. These findings demonstrate that inhibition of the complement cascade delays optic nerve axonal and RGC degeneration in retinal I/R. It appears that injured RGC are targeted and actively destroyed through complement mediated processes. These results may have implications for the pathophysiology and clinical management of ischemic retinal conditions.
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Affiliation(s)
- Markus H Kuehn
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA 52242, USA.
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35
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Loeffler DA, Camp DM, Bennett DA. Plaque complement activation and cognitive loss in Alzheimer's disease. J Neuroinflammation 2008; 5:9. [PMID: 18334032 PMCID: PMC2292690 DOI: 10.1186/1742-2094-5-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Accepted: 03/11/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Complement activation is increased in Alzheimer's disease (AD), but its significance is unclear. The objective of this study was to determine the relationship between complement activation and cognition during the development of AD. METHODS iC3b, C9, Bielschowsky, and Gallyas staining was performed on aged normal (n = 17), mild cognitively impaired (n = 12), and AD (n = 17-18) inferior temporal gyrus specimens. Plaques were counted in 10x fields with high numbers of Bielschowsky-stained plaques. One-way ANOVA was used to determine between-group differences for plaque counts and measures of cognitive function, and linear regression was used to evaluate global cognition as a function of Bielschowsky-stained plaques. Terms for iC3b- and C9-stained plaques were then added sequentially as additional predictors in a "mediation analysis" model. RESULTS Complement was detected on plaques in all groups, and on neurofibrillary tangles only in AD specimens. iC3b, C9, and Bielschowsky-stained plaque counts increased 2.5- to 3-fold in AD vs. other groups (all p < or = 0.01). C9 staining was present on some diffuse plaques, as well as on neuritic plaques. Bielschowsky-stained and complement-stained plaque counts were highly correlated, and were negatively correlated with cognitive measures. When the Bielschowsky plaque count was used as a predictor, its correlations with cognitive measures were statistically significant, but when iC3b and C9 plaque counts were added as additional predictors, these correlations were no longer significant. This loss of significance was attributed to multicollinearity, i.e., high correlations between Bielschowsky-stained and complement-stained plaque counts. CONCLUSION Both early-stage (iC3b) and late-stage (C9) complement activation occurs on neocortical plaques in subjects across the cognitive spectrum; contrary to previous reports, C9 is present on some diffuse plaques. Because of high correlations between complement-stained and Bielschowsky-stained plaque counts, quantitative assessment of the extent to which complement activation may mediate the relationship between plaques and cognitive function could not be performed. Additional studies with animal models of AD (if late-stage complement activation can be demonstrated), or possibly a trial in AD patients with an inhibitor of late-stage complement activation, may be necessary to determine the significance of this process in AD.
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Affiliation(s)
- David A Loeffler
- Neurology Research Laboratory, William Beaumont Hospital Research Institute, Royal Oak, MI 48073, USA.
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Mukherjee P, Thomas S, Pasinetti GM. Complement anaphylatoxin C5a neuroprotects through regulation of glutamate receptor subunit 2 in vitro and in vivo. J Neuroinflammation 2008; 5:5. [PMID: 18230183 PMCID: PMC2246107 DOI: 10.1186/1742-2094-5-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Accepted: 01/29/2008] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The complement system is thought to be involved in the pathogenesis of numerous neurological diseases. We previously reported that pre-treatment of murine cortico-hippocampal neuronal cultures with the complement derived anaphylatoxin C5a, protects against glutamate mediated apoptosis. Our present study with C5a receptor knock out (C5aRKO) mice corroborates that the deficiency of C5a renders C5aRKO mouse more susceptible to apoptotic injury in vivo. In this study we explored potential upstream mechanisms involved in C5a mediated neuroprotection in vivo and in vitro. METHODS Based on evidence suggesting that reduced expression of glutamate receptor subunit 2 (GluR2) may influence apoptosis in neurons, we studied the effect of human recombinant C5a on GluR2 expression in response to glutamate neurotoxicity. Glutamate analogs were injected into C5aRKO mice or used to treat in vitro neuronal culture and GluR2 expression were assessed in respect with cell death. RESULTS In C5aRKO mice we found that the neurons are more susceptible to excitotoxicity resulting in apoptotic injury in the absence of the C5a receptor compared to WT control mice. Our results suggest that C5a protects against apoptotic pathways in neurons in vitro and in vivo through regulation of GluR2 receptor expression. CONCLUSION Complement C5a neuroprotects through regulation of GluR2 receptor subunit.
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Affiliation(s)
- Piali Mukherjee
- Department of Psychiatry, Mount Sinai School of Medicine, 1 Gustav L,, Levy Place, New York, NY 10029, USA.
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Walker DG, Dalsing-Hernandez JE, Lue LF. Human postmortem brain-derived cerebrovascular smooth muscle cells express all genes of the classical complement pathway: a potential mechanism for vascular damage in cerebral amyloid angiopathy and Alzheimer's disease. Microvasc Res 2007; 75:411-9. [PMID: 18048067 DOI: 10.1016/j.mvr.2007.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2006] [Revised: 09/27/2007] [Accepted: 10/12/2007] [Indexed: 10/22/2022]
Abstract
Deposition of amyloid around blood vessels, known as cerebral amyloid angiopathy (CAA), is a major pathological feature found in the majority of Alzheimer's disease (AD) cases, and activated complement fragments have been detected on CAA deposits in AD brains. In this study, we demonstrate for the first time that human cerebrovascular smooth muscle cells (HCSMC) isolated from cortical vessels derived from postmortem brains can express mRNAs for complement genes C1qB, C1r, C1s, C2, C3, C4, C5, C6, C7, C8 and C9, the components of the classical complement pathway. Secretion of the corresponding complement proteins for these genes was also demonstrated, except for C1q and C5. Of particular significance was the observation that treatment of HCSMC with aggregated amyloid beta (Abeta) 1-42 increased expression of complement C3 mRNA and increased release of C3 protein. Abeta treatment of HCSMC also increased expression of C6 mRNA. Interferon-gamma induced expression and release of complement C1r, C1s, C2 and C4. As HCSMC are closely associated with Abeta deposits in vessels in the brain, their production of complement proteins could amplify the proinflammatory effects of amyloid in the perivascular environment, further compromising brain vascular integrity.
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MESH Headings
- Aged, 80 and over
- Alzheimer Disease/metabolism
- Alzheimer Disease/pathology
- Amyloid beta-Peptides/pharmacology
- Brain/blood supply
- Cadaver
- Cells, Cultured
- Cerebral Amyloid Angiopathy/metabolism
- Cerebral Amyloid Angiopathy/pathology
- Complement System Proteins/genetics
- Complement System Proteins/metabolism
- Culture Media, Conditioned/chemistry
- Culture Media, Conditioned/metabolism
- Gene Expression
- Humans
- Interferon-gamma/pharmacology
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Postmortem Changes
- RNA, Messenger/metabolism
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Affiliation(s)
- Douglas G Walker
- Laboratory of Neuroinflammation, Sun Health Research Institute, Sun City, Arizona, USA.
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Leite MI, Jones M, Ströbel P, Marx A, Gold R, Niks E, Verschuuren JJGM, Berrih-Aknin S, Scaravilli F, Canelhas A, Morgan BP, Vincent A, Willcox N. Myasthenia gravis thymus: complement vulnerability of epithelial and myoid cells, complement attack on them, and correlations with autoantibody status. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:893-905. [PMID: 17675582 PMCID: PMC1959483 DOI: 10.2353/ajpath.2007.070240] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In early-onset myasthenia gravis, the thymus contains lymph node-type infiltrates with frequent acetylcholine receptor (AChR)-specific germinal centers. Our recent evidence/two-step hypothesis implicates hyperplastic medullary thymic epithelial cells (expressing isolated AChR subunits) in provoking infiltration and thymic myoid cells (with intact AChR) in germinal center formation. To test this, we screened for complement attack in a wide range of typical generalized myasthenia patients. Regardless of the exact serology, thymi with sizeable infiltrates unexpectedly showed patchy up-regulation of both C5a receptor and terminal complement regulator CD59 on hyperplastic epithelial cells. These latter also showed deposits of activated C3b complement component, which appeared even heavier on infiltrating B cells, macrophages, and especially follicular dendritic cells. Myoid cells appeared particularly vulnerable to complement; few expressed the early complement regulators CD55, CD46, or CR1, and none were detectably CD59(+). Indeed, when exposed to infiltrates, and especially to germinal centers, myoid cells frequently labeled for C1q, C3b (25 to 48%), or even the terminal C9, with some showing obvious damage. This early/persistent complement attack on both epithelial and myoid cells strongly supports our hypothesis, especially implicating exposed myoid cells in germinal center formation/autoantibody diversification. Remarkably, the similar changes place many apparent AChR-seronegative patients in the same spectrum as the AChR-seropositive patients.
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Affiliation(s)
- Maria I Leite
- Department of Clinical Neurology, University of Oxford, Oxford, United Kingdom
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Szalai AJ, Hu X, Adams JE, Barnum SR. Complement in experimental autoimmune encephalomyelitis revisited: C3 is required for development of maximal disease. Mol Immunol 2007; 44:3132-6. [PMID: 17353050 PMCID: PMC1986644 DOI: 10.1016/j.molimm.2007.02.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 02/02/2007] [Accepted: 02/05/2007] [Indexed: 10/23/2022]
Abstract
Complement per se has been shown to play an important role in demyelinating disease but controversy remains regarding the role of C3 in the development and progression of experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. In this study, we used C3(-/-) mice to confirm previous findings that C3 is required for full development of EAE. Furthermore, C3(+/-) mice (with serum C3 levels 50% that of wild-type mice) developed EAE with a severity intermediate between wild-type and C3(-/-) mice. Importantly transfer of wild-type encephalitogenic T cells to C3(-/-) mice resulted in attenuated EAE. C3(-/-) mice with EAE had fewer CD4(+) and CD8(+) T cells in the CNS and 50% fewer of these cells produced IFN-gamma compared to wild-type mice. When treated with anti-CD3 antibody, CD4(+) T cells from wild-type and C3(-/-) mice had similar activation profiles as judged by IFN-gamma production and CD25 and CD69 expression, indicating there is no gross or intrinsic defect in T cells from C3(-/-) mice. T cells from primed C3(-/-) mice proliferated comparably to that of control T cells on re-stimulation with MOG peptide. Our results confirm a requirement for C3 for maximal development of EAE and suggest that receptors for C3-derived activation fragments might be a viable therapeutic target for prevention and treatment demyelinating disease.
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Affiliation(s)
- Alexander J. Szalai
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Xianzhen Hu
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jillian E. Adams
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Scott R. Barnum
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
- *Corresponding Author: Dr. Scott R. Barnum, Department of Microbiology, University of Alabama at Birmingham, 845 19 St. S., BBRB/842, Birmingham, AL 35294. E-mail address:
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Role of inflammation and cellular stress in brain injury and central nervous system diseases. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.cnr.2006.09.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Ohlsson M, Svensson M. Early decompression of the injured optic nerve reduces axonal degeneration and improves functional outcome in the adult rat. Exp Brain Res 2006; 179:121-30. [PMID: 17103208 DOI: 10.1007/s00221-006-0775-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Accepted: 10/23/2006] [Indexed: 11/30/2022]
Abstract
The putative beneficial role of an early decompression of injured CNS tissue following trauma remains controversial. In this study, we approach this scientific query using a standardized injury of the optic nerve in adult rats. Adult Sprague-Dawley rats were subjected to a standardized optic nerve constriction injury by applying a loose ligature around the nerve for 5 min, 1, 6 or 24 h. All animals were sacrificed at 28 dpi. Viable axons distal to the injury were quantified using semithin sections, and regenerative fibers were studied using antisera to neurofilament and GAP43. Axonal degeneration and glial scar development were analyzed using Fluoro-Jade staining and anti-GFAP, respectively. Visual function was studied with visual evoked potentials (VEP). No significant differences were observed between 1 and 6 h of optic nerve compression. However, the number of viable axons analyzed with neurofilament and on semithin sections, decreased significantly between 6 and 24 h, paralleled by an increase in Fluoro-Jade labeled axonal debris (P < 0.001). GFAP-IR density was significantly higher (P < 0.001) in the 24 h compression group in comparison to 6 h. VEP showed preserved, but impaired visual function in animals subjected to compression up to 6 h, compared to an abolished cortical response at 24 h. Regenerative GAP43-positive sprouts were occasionally found distal to the lesion in animals subjected to compression up to 6 h, but not at 24 h. These findings suggest that early optic nerve decompression within hours after the initial trauma is beneficial for functional outcome.
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Affiliation(s)
- Marcus Ohlsson
- Department of Clinical Neuroscience, Section of Neurosurgery, Karolinska Institutet, Karolinska Hospital, Solna, Stockholm 171 76, Sweden.
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Morgan BP, Chamberlain-Banoub J, Neal JW, Song W, Mizuno M, Harris CL. The membrane attack pathway of complement drives pathology in passively induced experimental autoimmune myasthenia gravis in mice. Clin Exp Immunol 2006; 146:294-302. [PMID: 17034582 PMCID: PMC1942050 DOI: 10.1111/j.1365-2249.2006.03205.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2006] [Indexed: 11/30/2022] Open
Abstract
The human neuromuscular disease myasthenia gravis (MG) is characterized by the generation of autoantibodies reactive with nicotinic acetylcholine receptors (AChR) that cause loss of AChR from the neuromuscular end-plate with resultant failure of neuromuscular transmission. A role for complement (C) in AChR loss has been suggested based upon morphological identification of C at the end-plate in MG and from the effects of C inhibition in murine models. Here we provide further evidence implicating C, and specifically the membrane attack complex (MAC), in a mouse model of MG. Mice deficient in the C regulators Daf1 and/or Cd59a were tested in the model. Wild-type mice were resistant to disease while mice deficient in Daf1 had mild disease symptoms with evidence of C activation and AChR loss at end-plates. Cd59a-deficient mice had very mild disease with some muscle inflammation and essentially undamaged end-plates. In contrast, mice deficient in both C regulators developed a severe paralytic disease with marked muscle inflammation and loss of end-plates. Inhibition of MAC assembly abrogated clinical disease in these double-deficient mice, demonstrating conclusively that MAC formation was driving pathology in the model. These findings provoke us to suggest that current anti-C therapeutics targeting MAC assembly will be beneficial in MG patients resistant to conventional therapies.
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Affiliation(s)
- B P Morgan
- Department of Pathology, School of Medicine, Cardiff University, Cardiff, UK.
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Woodruff TM, Crane JW, Proctor LM, Buller KM, Shek AB, de Vos K, Pollitt S, Williams HM, Shiels IA, Monk PN, Taylor SM. Therapeutic activity of C5a receptor antagonists in a rat model of neurodegeneration. FASEB J 2006; 20:1407-17. [PMID: 16816116 DOI: 10.1096/fj.05-5814com] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The complement system is thought to be involved in the pathogenesis of numerous neurological diseases, although its precise role remains controversial. In this study we used orally active C5a receptor antagonists (PMX53 and PMX205) developed in our laboratories in a rat model of 3-nitropropionic acid (3-NP) -induced Huntington's disease. Administration of the C5a antagonists (10 mg/kg/day, oral) either 48 h pre- or 48 h post-toxin significantly reduced body weight loss, anorexia, and behavioral and motor deficits associated with 3-NP intoxication. Striatal lesion size, apoptosis, neutrophil infiltration, and hemorrhage were also significantly reduced in C5a antagonist-treated rats. Immunohistochemical analysis demonstrated marked deposition of C3 and C9, and up-regulation of C5a receptors on neuronal cells at the time of lesion formation. Inhibition of prostaglandins or TNF-alpha with ibuprofen or infliximab had no effect in this model. The C5a antagonists did not affect 3-NP-induced cell death when added directly to rat striatal neuronal cultures, indicating a secondary mechanism of action in vivo. Our findings demonstrate for the first time that complement activation in the brain, particularly C5a, is a key event in the pathogenesis of this disease model, and suggest a future role for inhibitors of C5a in the treatment of neurodegenerative diseases.
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Affiliation(s)
- Trent M Woodruff
- Promics Ltd., The University of Queensland, Brisbane, QLD 4072, Australia.
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Hoffman WH, Cudrici CD, Zafranskaia E, Rus H. Complement activation in diabetic ketoacidosis brains. Exp Mol Pathol 2006; 80:283-8. [PMID: 16494864 DOI: 10.1016/j.yexmp.2005.12.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Accepted: 12/20/2005] [Indexed: 12/23/2022]
Abstract
The metabolic crisis of diabetic ketoacidosis (DKA) and its treatment can result in the life-threatening complication of clinical brain edema. However, there is limited information available regarding either the pathophysiology or histology of this acute complication. It has been reported that DKA and its treatment are associated with a systemic inflammatory response involving the activation of the complement cascade with increases of SC5b-9 serum level. We studied the brains of two patients, both of whom died as the result of DKA-related brain edema, for the presence of C5b-9, C1q and the expression of the CD59. Apoptosis was also evaluated by the TUNEL method. All regions of the brain demonstrated varying degrees of C5b-9 deposits on neurons, oligodendrocytes and blood vessels. C5b-9 was co-localized with C1q, suggesting the activation of classical pathway. No expression of CD59 was found on neurons, oligodendrocytes or blood vessels in DKA brain, but this complement inhibitor was present on these cells in the normal brain. Rarely, C5b-9 was co-localized with apoptotic neurons and OLG. Our data demonstrate that the metabolic crisis of DKA results in a loss of CD59 expression and assembly of C5b-9 on neurons and oligodendrocytes, suggesting that complement activation and C5b-9 may play a role in the pathophysiology of the brain edema of DKA.
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Affiliation(s)
- William H Hoffman
- Department of Pediatrics, Medical College of Georgia, Augusta, GA 30912, USA
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Mocco J, Sughrue ME, Ducruet AF, Komotar RJ, Sosunov SA, Connolly ES. The complement system: a potential target for stroke therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 586:189-201. [PMID: 16893073 DOI: 10.1007/0-387-34134-x_13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- J Mocco
- Department of Neurological Surgery, Columbia University, College of Physicians & Surgeons, New York, New York 10032, USA
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Boos L, Szalai AJ, Barnum SR. C3a expressed in the central nervous system protects against LPS-induced shock. Neurosci Lett 2005; 387:68-71. [PMID: 16085360 DOI: 10.1016/j.neulet.2005.07.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Revised: 06/28/2005] [Accepted: 07/11/2005] [Indexed: 11/22/2022]
Abstract
Complement is implicated in the pathogenesis of inflammatory disorders of the central nervous system (CNS), like multiple sclerosis, Alzheimer's disease, and trauma. The anaphylatoxins C3a and C5a are thought to be the major contributors to complement-mediated inflammation in the CNS, likely mediating their effects via their ability to attract and activate leukocytes and common capacity to augment inflammation. For example, in experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis, CNS-specific expression of C3a in C3a/GFAP transgenic mice renders them prone to massive cellular infiltration of the CNS and increases their mortality. In contrast, other studies have suggested that C3a can function in an anti-inflammatory fashion in the CNS, by inducing neurotrophin production and preventing NMDA-mediated neurotoxicity. To further investigate the seemingly paradoxical role of C3a in acute inflammation of the brain, we studied the pathogenesis of endotoxin shock in C3a/GFAP transgenic, C3a receptor-deficient (C3aR-/-) and C3a/GFAPxC3aR-/- mutant mice. Here we report that C3a/GFAP mice were significantly more resistant to endotoxin-induced lethality than wild-type and C3aR-/- mice. Surprisingly, C3a/GFAPxC3aR-/- hybrids were also significantly protected, indicating that C3a exerts its protective anti-inflammatory effect either directly or via an as yet unidentified non-canonical C3aR.
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Affiliation(s)
- Laura Boos
- Department of Microbiology, University of Alabama at Birmingham, 845 19th St. S., BBRB/842, Birmingham, AL 35294, USA
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Hauwel M, Furon E, Canova C, Griffiths M, Neal J, Gasque P. Innate (inherent) control of brain infection, brain inflammation and brain repair: the role of microglia, astrocytes, "protective" glial stem cells and stromal ependymal cells. ACTA ACUST UNITED AC 2005; 48:220-33. [PMID: 15850661 DOI: 10.1016/j.brainresrev.2004.12.012] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2004] [Accepted: 12/09/2004] [Indexed: 12/21/2022]
Abstract
In invertebrates and primitive vertebrates, the brain contains large numbers of "professional" macrophages associated with neurones, ependymal tanycytes and radial glia to promote robust regenerative capacity. In higher vertebrates, hematogenous cells are largely excluded from the brain, and innate immune molecules and receptors produced by the resident "amateur" macrophages (microglia, astrocytes and ependymal cells) control pathogen infiltration and clearance of toxic cell debris. However, there is minimal capacity for regeneration. The transfer of function from hematogenous cells to macroglia and microglia is associated with the sophistication of a yet poorly-characterized neurone-glia network. This evolutionary pattern may have been necessary to reduce the risk of autoimmune attack while preserving the neuronal web but the ability to repair central nervous system damage may have been sacrificed in the process. We herein argue that it may be possible to re-educate and stimulate the resident phagocytes to promote clearance of pathogens (e.g., Prion), toxic cell debris (e.g., amyloid fibrils and myelin) and apoptotic cells. Moreover, as part of this greater division of labour between cell types in vertebrate brains, it may be possible to harness the newly described properties of glial stem cells in neuronal protection (revitalization) rather than replacement, and to control brain inflammation. We will also highlight the emerging roles of stromal ependymal cells in controlling stem cell production and migration into areas of brain damage. Understanding the mechanisms involved in the nurturing of damaged neurons by protective glial stem cells with the safe clearance of cell debris could lead to remedial strategies for chronic brain diseases.
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Affiliation(s)
- Mathieu Hauwel
- Department of Medical Biochemistry and Immunology, Brain Inflammation and Immunity Group (BIIG), University of Wales College of Medicine, Tenovus Building, Heath Park, Cardiff, UK
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Abstract
Complement activation participates in tissue injury after temporary loss of blood flow (ischemia-reperfusion injury). Recently reported evidence indicates that complement activation is a pathologic mechanism of injury in the post-hypoxic-ischemic neonatal brain. Therefore, recently developed complement inhibitors may find a role in the amelioration of neonatal hypoxic-ischemic cerebral injury. Further research is needed to better define the role of complement in human neonatal cerebral injury and to determine the neuroprotective effect and safety of pharmacologic agents designed to inhibit complement.
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Affiliation(s)
- Herbert A Lassiter
- Division of Neonatal Medicine and Neonatal Immunology Research Laboratory, Kosair Children's Hospital Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY 40202-3830, USA.
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Alexander JJ, Bao L, Jacob A, Kraus DM, Holers VM, Quigg RJ. Administration of the soluble complement inhibitor, Crry-Ig, reduces inflammation and aquaporin 4 expression in lupus cerebritis. Biochim Biophys Acta Mol Basis Dis 2004; 1639:169-76. [PMID: 14636948 DOI: 10.1016/j.bbadis.2003.09.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Changes in brain water and cerebral volume can lead to brain edema that may be one of the underlying causes of death in many neurological diseases. Cerebral water content is regulated by aquaporin 4 (AQ4) present in astrocytic end feet and around blood vessels. In systemic lupus erythematosus (SLE), magnetic resonance imaging (MRI) studies of the brain have demonstrated lesions with the prominent appearance of edema. Activation of complement may play a significant role in the pathogenesis of lupus cerebritis by causing inflammation that can lead to edema. In this study, the well-established MRL/lpr lupus mouse model was used to evaluate the role of complement in lupus cerebritis. IgG and C1q colocalized in perivascular deposits indicating that the blood-brain barrier was compromised. Both RNA and protein expressions of AQ4 were significantly increased in brains of MRL/lpr mice. Chronic administration of the soluble complement inhibitor, Crry-Ig, reduced inflammation as measured by decreased accumulation of IgG. In contrast to control MRL/lpr mice, AQ4 expression in complement inhibited MRL/lpr mice was not changed relative to untreated congenic controls. These results illustrate that complement activation in brains of lupus mice leads to enhanced AQ4 expression and inflammation. It is conceivable that increased AQ4 expression results in cerebral edema and hence complement inhibition may provide a new therapeutic option in inflammatory cerebral disorders such as lupus cerebritis.
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Affiliation(s)
- Jessy J Alexander
- Department of Medicine, Section of Nephrology, University of Chicago, Chicago, IL 60637, USA.
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