1
|
Benedet AL, Labbe A, Lemay P, Zimmer ER, Pascoal TA, Leuzy A, Mathotaarachchi S, Mohades S, Shin M, Dionne-Laporte A, Beaudry T, Picard C, Gauthier S, Poirier J, Rouleau G, Rosa-Neto P. Epistasis analysis links immune cascades and cerebral amyloidosis. J Neuroinflammation 2015; 12:227. [PMID: 26626881 PMCID: PMC4666175 DOI: 10.1186/s12974-015-0436-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/16/2015] [Indexed: 12/21/2022] Open
Abstract
Background Several lines of evidence suggest the involvement of neuroinflammatory changes in Alzheimer’s disease (AD) pathophysiology such as amyloidosis and neurodegeneration. In fact, genome-wide association studies (GWAS) have shown a link between genes involved in neuroinflammation and AD. In order to further investigate whether interactions between candidate genetic variances coding for neuroinflammatory molecules are associated with brain amyloid β (Aβ) fibrillary accumulation, we conducted an epistasis analysis on a pool of genes associated with molecular mediators of inflammation. Methods [18F]Florbetapir positron emission tomography (PET) imaging was employed to assess brain Aβ levels in 417 participants from ADNI-GO/2 and posteriorly 174 from ADNI-1. IL-1β, IL4, IL6, IL6r, IL10, IL12, IL18, C5, and C9 genes were chosen based on previous studies conducted in AD patients. Using the [18F]florbetapir standardized uptake value ratio (SUVR) as a quantitative measure of fibrillary Aβ, epistasis analyses were performed between two sets of markers of immune-related genes using gender, diagnosis, and apolipoprotein E (APOE) as covariates. Voxel-based analyses were also conducted. The results were corrected for multiple comparison tests. Cerebrospinal fluid (CSF) Aβ1-42/phosphorylated tau (p-tau) ratio concentrations were used to confirm such associations. Results Epistasis analysis unveiled two significant single nucleotide polymorphism (SNP)-SNP interactions (false discovery rate (FDR) threshold 0.1), both interactions between C9 gene (rs261752) and IL6r gene (rs4240872, rs7514452). In a combined sample, the interactions were confirmed (p ≤ 10–5) and associated with amyloid accumulation within cognitively normal and AD spectrum groups. Voxel-based analysis corroborated initial findings. CSF biomarker (Aβ1-42/p-tau) confirmed the genetic interaction. Additionally, rs4240872 and rs7514452 SNPs were shown to be associated with CSF and plasma concentrations of IL6r protein. Conclusions Certain allele combinations involving IL6r and C9 genes are associated with Aβ burden in the brain. Hypothesis-driven search for epistasis is a valuable strategy for investigating imaging endophenotypes in complex neurodegenerative diseases. Electronic supplementary material The online version of this article (doi:10.1186/s12974-015-0436-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Andréa L Benedet
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada. .,CAPES Foundation, Ministry of Education of Brazil, Brasília, Brazil.
| | - Aurélie Labbe
- Douglas Hospital Research Centre, McGill University, Montreal, Canada. .,Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Canada. .,Department of Psychiatry, McGill University, Montreal, Canada.
| | - Philippe Lemay
- Department of Biochemistry, Université de Montréal, Montréal, Canada.
| | - Eduardo R Zimmer
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada. .,Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil. .,Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
| | - Tharick A Pascoal
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada.
| | - Antoine Leuzy
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada. .,Department of NVS, Center for Alzheimer Research, Translational Alzheimer Neurobiology, Karolinska Institutet, Stockholm, Sweden. .,Alzheimer's Disease Research Unit, McGill University Research Centre for Studies in Aging, McGill University, Montreal, Canada.
| | - Sulantha Mathotaarachchi
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada.
| | - Sara Mohades
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada.
| | - Monica Shin
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada.
| | - Alexandre Dionne-Laporte
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada. .,Montreal Neurological Institute, Montreal, Canada.
| | - Thomas Beaudry
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada.
| | - Cynthia Picard
- Douglas Hospital Research Centre, McGill University, Montreal, Canada.
| | - Serge Gauthier
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.
| | - Judes Poirier
- Douglas Hospital Research Centre, McGill University, Montreal, Canada. .,Alzheimer's Disease Research Unit, McGill University Research Centre for Studies in Aging, McGill University, Montreal, Canada. .,Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.
| | - Guy Rouleau
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada. .,Montreal Neurological Institute, Montreal, Canada.
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, 6825 LaSalle Blvd, H4H 1R3, Montreal, QC, Canada. .,Alzheimer's Disease Research Unit, McGill University Research Centre for Studies in Aging, McGill University, Montreal, Canada. .,Department of Neurology and Neurosurgery, McGill University, Montreal, Canada. .,Montreal Neurological Institute, Montreal, Canada.
| | | |
Collapse
|
2
|
Kumari R, Astafurov K, Genis A, Danias J. Differential Effects of C1qa Ablation on Glaucomatous Damage in Two Sexes in DBA/2NNia Mice. PLoS One 2015; 10:e0142199. [PMID: 26544197 PMCID: PMC4636422 DOI: 10.1371/journal.pone.0142199] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 10/18/2015] [Indexed: 11/19/2022] Open
Abstract
PURPOSE To determine the sex and age-related effects of C1qa ablation on retinal ganglion cell (RGC) and optic nerve (ON) axonal loss in a mouse model of glaucomatous neurodegeneration. METHODS Congenic C1qa mice were generated in the DBA/2NNia background. Female and male knockout (-/-), heterozygous (+/-), and wild type (+/+) mice were aged up to 14 months and IOPs were recorded in a subset of animals. Retinas of mice from all three groups at 5-6, 9-10 and 11-13 months of age were flat-mounted after retrograde labeling with Fluorogold. Imaged retinas were scored (RGC score) semi-quantitatively on a 10 point scale by two independent observers. A subset of retinas and optic nerves were also used for measurement of total number of RGCs. Semi-thin sections of ON were imaged and graded (ON score) for the amount of axonal damage semi-quantitatively, by two masked observers. Analysis of covariance (ANCOVA) was used for statistical comparisons. Microglial cells in flat-mounted retinas of 5-6 month old C1qa -/- and C1qa +/+ mice were used for assessment of microglial activation utilizing morphological criteria. RESULTS Female C1qa -/- mice had significantly higher IOP (p<0.000001, ANOVA) between 8 and 13 months of age compared to C1qa +/+ animals. No differences in IOPs between animals of the three genotypes were observed in males. At 5-6 months of age, there was no difference in RGC or ON scores between the three genotypes in animals of either sex. At 9-10 months of age, female mice didn't show significant differences in RGC or ON scores between the three genotypes. However, male C1qa -/- and C1qa +/- mice of the same age had better RGC and ON scores (p<0.003 and p<0.05, ANCOVA, for RGC and ON scores, respectively) compared with C1qa +/+ mice. At 11-13 months of age, female C1qa -/- mice had better RGC scores (p<0.006, ANCOVA) compared to C1qa +/+ and C1qa +/- animals. Accordingly, C1qa -/- mice had higher RGC counts (p<0.03, t-test) compared to C1qa +/+ animals. In male mice, there was a tendency for 12 month old C1qa -/- animals to have better RGC scores and higher RGC counts, but this didn't reach statistical significance. ON scores in 11-13 month old animals of either sex were not different between all three genotype. Microglial activation in male 5-6 month old C1qa -/- mice was decreased compared to C1qa +/+ animals; no such effect was seen in females. CONCLUSIONS Absence of C1qa ameliorates RGC and ON loss in the DBA/2NNia strain, but this effect differs between the two sexes. C1q-mediated RGC damage seems to be more potent than IOP-mediated RGC loss. In contrast, C1qa absence provides axonal protection early on, but this protection cannot overcome the effects of significant IOP elevation.
Collapse
Affiliation(s)
- Ruma Kumari
- Department of Cell Biology, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, United States of America
- State University of New York (SUNY) Eye Institute, Brooklyn, New York, United States of America
- * E-mail: (RK); (JD)
| | - Konstantin Astafurov
- Department of Cell Biology, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, United States of America
- State University of New York (SUNY) Eye Institute, Brooklyn, New York, United States of America
| | - Alina Genis
- Department of Ophthalmology, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, United States of America
- State University of New York (SUNY) Eye Institute, Brooklyn, New York, United States of America
| | - John Danias
- Department of Cell Biology, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, United States of America
- Department of Ophthalmology, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, United States of America
- State University of New York (SUNY) Eye Institute, Brooklyn, New York, United States of America
- * E-mail: (RK); (JD)
| |
Collapse
|
3
|
Shen Y, Yang L, Li R. What does complement do in Alzheimer's disease? Old molecules with new insights. Transl Neurodegener 2013; 2:21. [PMID: 24119446 PMCID: PMC3853043 DOI: 10.1186/2047-9158-2-21] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 10/01/2013] [Indexed: 11/25/2022] Open
Abstract
Increasing evidence suggests that inflammatory and immune components in brain are important in Alzheimer's disease (AD) and anti-inflammatory and immunotherapeutic approaches may be amenable to AD treatment. It is known that complement activation occurs in the brain of patients with AD, and contributes to a local inflammatory state development which is correlated with cognitive impairment. In addition to the complement's critical role in the innate immune system recognizing and killing, or targeting for destruction, complement proteins can also interact with cell surface receptors to promote a local inflammatory response and contributes to the protection and healing of the host. On the other hand, complement activation also causes inflammation and cell damage as an essential immune function to eliminate cell debris and potentially toxic protein aggregates. It is the balance of these seemingly competing events that influences the ultimate state of neuronal function. Our mini review will be focusing on the unique molecular interactions happening in the AD development, the functional outcomes of those interactions, as well as the contribution of each element to AD.
Collapse
Affiliation(s)
- Yong Shen
- Center for Advanced Therapeutic Strategies for Brain Disorders, Roskamp Institute, 2040 Whitfield Avenue, Sarasota, USA
- Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Libang Yang
- Department of Pediatrics, School of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rena Li
- Center for Hormones Advanced Science and Education, Roskamp Institute, 2040 Whitfield Avenue, Sarasota, Florida, USA
| |
Collapse
|
4
|
Bang J, Jeon WK, Lee IS, Han JS, Kim BY. Biphasic functional regulation in hippocampus of rat with chronic cerebral hypoperfusion induced by permanent occlusion of bilateral common carotid artery. PLoS One 2013; 8:e70093. [PMID: 23936146 PMCID: PMC3728362 DOI: 10.1371/journal.pone.0070093] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/18/2013] [Indexed: 11/18/2022] Open
Abstract
Background Chronic cerebral hypoperfusion induced by permanent occlusion of the bilateral common carotid artery (BCCAO) in rats has been commonly used for the study of Alzheimer’s disease and vascular dementia. Despite the apparent cognitive dysfunction in rats with BCCAO, the molecular markers or pathways involved in the pathological alternation have not been clearly identified. Methods Temporal changes (sham, 21, 35, 45, 55 and 70 days) in gene expression in the hippocampus of rats after BCCAO were measured using time-course microarray analysis. Gene Ontology (GO) and pathway analyses were performed to identify the functional involvement of temporally regulated genes in BCCAO. Results Two major gene expression patterns were observed in the hippocampus of rats after BCCAO. One pattern, which was composed of 341 early up-regulated genes after the surgical procedure, was dominantly involved in immune-related biological functions (false discovery rate [FDR]<0.01). Another pattern composed of 182 temporally delayed down-regulated genes was involved in sensory perception such as olfactory and cognition functions (FDR<0.01). In addition to the two gene expression patterns, the temporal change of GO and the pathway activities using all differentially expressed genes also confirmed that an immune response was the main early change, whereas sensory functions were delayed responses. Moreover, we identified FADD and SOCS3 as possible core genes in the sensory function loss process using text-based mining and interaction network analysis. Conclusions The biphasic regulatory mechanism first reported here could provide molecular evidence of BCCAO-induced impaired memory in rats as well as mechanism of the development of vascular dementia.
Collapse
Affiliation(s)
- Jihye Bang
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea
| | - Won Kyung Jeon
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea
| | - In Sun Lee
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea
| | - Jung-Soo Han
- Department of Biological sciences, Konkuk University, Seoul, Republic of Korea
| | - Bu-Yeo Kim
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon, Republic of Korea
- * E-mail:
| |
Collapse
|
5
|
Timár KK, Dallos A, Kiss M, Husz S, Bos JD, Asghar SS. Expression of terminal complement components by human keratinocytes. Mol Immunol 2007; 44:2578-86. [PMID: 17267037 DOI: 10.1016/j.molimm.2006.12.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 12/10/2006] [Accepted: 12/14/2006] [Indexed: 11/16/2022]
Abstract
Human keratinocytes are important constituents of the skin immune system. They produce several cytokines, chemokines as well as some complement proteins. As regards soluble complement proteins, so far keratinocytes have been shown to synthesize only C3, factor B, factor H and factor I. Synthesis and regulation of synthesis of other complement proteins has not yet been studied. Here we studied the synthesis of terminal complement components, C5-C9 by human keratinocytes. We also studied the regulation of terminal complement synthesis in keratinocytes by several cytokines, namely, IL-1alpha, IL-2, IL-6, TGF-beta1, TNF-alpha, and IFN-gamma. Human keratinocytes constitutively expressed C5, C7, C8gamma and C9 mRNA but not C6, C8alpha and C8beta mRNA. They released C7 and C9, but not C5, C6 and C8. None of the cytokines tested had any influence on the synthesis of terminal components except TNF-alpha, which strongly upregulated C9 production. In conclusion, we demonstrate that keratinocytes are capable of synthesizing some of the terminal complement components and that the synthesis of C9 is regulated by TNF-alpha.
Collapse
Affiliation(s)
- Krisztina K Timár
- Department of Dermatology, Academic Medical Center, University of Amsterdam, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|
6
|
Miklossy J, Arai T, Guo JP, Klegeris A, Yu S, McGeer EG, McGeer PL. LRRK2 expression in normal and pathologic human brain and in human cell lines. J Neuropathol Exp Neurol 2006; 65:953-63. [PMID: 17021400 PMCID: PMC7185781 DOI: 10.1097/01.jnen.0000235121.98052.54] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) have been recently identified in families with autosomal-dominant late-onset Parkinson disease. We report that by reverse transcriptase-polymerase chain reaction, the mRNA of LRRK2 is expressed in soluble extracts of human brain, liver, and heart and in cultured human astrocytes, microglia, and oligodendroglia as well as in human neuroblastoma cell lines. We find by Western blotting using a polyclonal antibody of the leucine-rich repeat kinase 2 protein (Lrrk2) specific for C-terminal residues 2,511-2,527 that an apparent full-length protein and several of its fractions are expressed in soluble extracts of normal human brain. By immunocytochemistry, the antibody recognizes neurons, and more weakly astrocytes and microglia, in normal brain tissue. It intensely labels Lewy bodies in Parkinson disease and related neurodegenerative disorders. It also labels a subset of neurofibrillary tangles in Alzheimer disease and the Parkinsonism dementia complex of Guam (PDCG). It labels thorn-shaped astrocytes and oligodendroglial coiled bodies in PDCG; oligodendroglial inclusions in multiple system atrophy; Pick bodies in Pick disease; nuclear and cytoplasmic inclusions in Huntington disease; and intraneuronal and glial inclusions in amyotrophic lateral sclerosis. In summary, LRRK2 is constitutively expressed in neurons and also in glial cells of human brain. It strongly associates with pathological inclusions in several neurodegenerative disorders.
Collapse
Affiliation(s)
- Judith Miklossy
- University of British Columbia, Kinsmen Laboratory of Neurological Research, Vancouver, BC, Canada
| | | | - Jian-Ping Guo
- University of British Columbia, Kinsmen Laboratory of Neurological Research, Vancouver, BC, Canada
| | - Andis Klegeris
- University of British Columbia, Kinsmen Laboratory of Neurological Research, Vancouver, BC, Canada
| | - Sheng Yu
- University of British Columbia, Kinsmen Laboratory of Neurological Research, Vancouver, BC, Canada
| | - Edith G. McGeer
- University of British Columbia, Kinsmen Laboratory of Neurological Research, Vancouver, BC, Canada
| | - Patrick L. McGeer
- University of British Columbia, Kinsmen Laboratory of Neurological Research, Vancouver, BC, Canada
- Send correspondence and reprint requests to: Patrick L. McGeer, MD, PhD, Kinsmen Laboratory of Neurological Research, The University of British Columbia, Vancouver, BC, V6T 1Z3 Canada; E-mail:
| |
Collapse
|
7
|
Arai T, Miklossy J, Klegeris A, Guo JP, McGeer PL. Thrombin and prothrombin are expressed by neurons and glial cells and accumulate in neurofibrillary tangles in Alzheimer disease brain. J Neuropathol Exp Neurol 2006; 65:19-25. [PMID: 16410745 DOI: 10.1097/01.jnen.0000196133.74087.cb] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Thrombin is a serine protease that is generated by proteolytic cleavage of its precursor, prothrombin. We previously showed that thrombin proteolyses the microtubule-associated protein tau and that phosphorylation of tau inhibits this process. To characterize further the role of thrombin in the brain, we investigated prothrombin and thrombin expression in cultured brain cells and in brains of control, Alzheimer disease (AD) and parkinsonism-dementia complex of Guam (PDCG). We show by reverse transcriptase-polymerase chain reaction that prothrombin mRNA is expressed in brain tissues, neuroblastoma cells, and cultured human astrocytes, oligodendrocytes, and microglial cells. We also show by immunohistochemistry that the proteins prothrombin and thrombin are present in brain using specific monoclonal and polyclonal antibodies for both proteins. All antibodies stained residual serum in blood vessels, as well as normal pyramidal neurons and their processes, and some astrocytes. Additionally, in AD and PDCG cases, all antibodies stained extra- and intracellular neurofibrillary tangles (NFTs), senile plaques, and reactive microglial cells. The ubiquitous expression of prothrombin and thrombin in brain cells suggests that thrombin plays an important physiological role in normal brain. The accumulation of thrombin and prothrombin in NFTs supports the hypothesis that thrombin may be involved in tau proteolysis and that failure to metabolize tau may lead to its aggregation in neurodegenerative diseases.
Collapse
Affiliation(s)
- Tetsuaki Arai
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, BC, Canada
| | | | | | | | | |
Collapse
|
8
|
Ten VS, Sosunov SA, Mazer SP, Stark RI, Caspersen C, Sughrue ME, Botto M, Connolly ES, Pinsky DJ. C1q-deficiency is neuroprotective against hypoxic-ischemic brain injury in neonatal mice. Stroke 2005; 36:2244-50. [PMID: 16179576 DOI: 10.1161/01.str.0000182237.20807.d0] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE This study was undertaken to determine whether the initial component of the classical complement (C) activation pathway contributes to hypoxic-ischemic brain injury in neonatal mice. METHODS Hypoxia-ischemia (HI) was produced in C1q(-/-) and wild-type (WT) neonatal mice. At 24 hours after HI, neonatal mouse reflex performance and cerebral infarct volume were assessed. Long-term outcomes were measured by water-maze performance and degree of cerebral atrophy at 7 to 8 weeks after HI. Activation of circulating neutrophils, and C1q, C3, and neutrophil deposition in brains were examined. RESULTS C1q(-/-) mice were significantly protected against HI (mean+/-SE infarct volume in C1q(-/-) mice=17.3+/-5.5% versus 53.6+/-6.8% in WT mice; P<0.0001) and exhibited significantly less neurofunctional deficit compared with WT mice. Immunostaining revealed significantly greater deposition of C3 (and C1q) as well as granulocytes in the infarcted brains in WT mice compared with C1q(-/-) animals. Activation of circulating leukocytes was significantly decreased in C1q(-/-) mice compared with WT mice, which correlated strongly (r=0.7) with cerebral infarct volumes. CONCLUSIONS Cerebral deposition of C1q and C3 after hypoxic-ischemic insult is associated with significantly greater neurologic damage in WT mice compared with C1q(-/-) mice, providing strong evidence that the classical C pathway contributes to the hypoxic-ischemic brain injury. Significantly decreased activation of circulating neutrophils associated with diminished local accumulation and attenuation of brain injury in C1q(-/-) mice suggests a potential cellular mechanism by which C1q mediates neurodegeneration in HI.
Collapse
Affiliation(s)
- Vadim S Ten
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
The spectrum of inflammatory diseases is nowadays considered to include diverse diseases of the central nervous system (CNS). Current evidence suggests that syndromes such as Alzheimer's disease (AD) have important inflammatory and immune components and may be amenable to treatment by anti-inflammatory and immunotherapeutic approaches. Compelling evidence has been reported that complement activation occurs in the brain with Alzheimer's disease, and that this contributes to the development of a local inflammatory state that is correlated with cognitive dysfunction. The complement system is a critical element of the innate immune system recognizing and killing, or targeting for destruction, otherwise pathogenic organisms. In addition to triggering the generation of a membranolytic complex, complement proteins interact with cell surface receptors to promote a local inflammatory response that contributes to the protection and healing of the host. Complement activation causes inflammation and cell damage, yet it is an essential component in trying to eliminate cell debris and potentially toxic protein aggregates. It is the balance of these seemingly competing events--the "Yin" and the "Yang"--that influences the ultimate state of neuronal function. Knowledge of the unique molecular interactions that occur in the development of Alzheimer's disease, the functional consequences of those interactions, and the proportional contribution of each element to this disorder, should facilitate the design of effective therapeutic strategies for this disease.
Collapse
Affiliation(s)
- Yong Shen
- Haldeman Laboratory of Molecular and Cellular Neurobiology, Sun Health Research Institute, 10515 West Santa Fe Drive, Sun City, AZ 85351, USA.
| | | |
Collapse
|