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Chio JCT, Punjani N, Hejrati N, Zavvarian MM, Hong J, Fehlings MG. Extracellular Matrix and Oxidative Stress Following Traumatic Spinal Cord Injury: Physiological and Pathophysiological Roles and Opportunities for Therapeutic Intervention. Antioxid Redox Signal 2022; 37:184-207. [PMID: 34465134 DOI: 10.1089/ars.2021.0120] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Significance: Traumatic spinal cord injury (SCI) causes significant disruption to neuronal, glial, vascular, and extracellular elements. The spinal cord extracellular matrix (ECM) comprises structural and communication proteins that are involved in reparative and regenerative processes after SCI. In the healthy spinal cord, the ECM helps maintain spinal cord homeostasis. After SCI, the damaged ECM limits plasticity and contributes to inflammation through the expression of damage-associated molecules such as proteoglycans. Recent Advances: Considerable insights have been gained by characterizing the origins of the gliotic and fibrotic scars, which not only reduce the spread of injury but also limit neuroregeneration. These properties likely limit the success of therapies used to treat patients with SCI. The ECM, which is a major contributor to the scars and normal physiological functions of the spinal cord, represents an exciting therapeutic target to enhance recovery post-SCI. Critical Issue: Various ECM-based preclinical therapies have been developed. These include disrupting scar components, inhibiting activity of ECM metalloproteinases, and maintaining iron homeostasis. Biomaterials have also been explored. However, the majority of these treatments have not experienced successful clinical translation. This could be due to the ECM and scars' polarizing roles. Future Directions: This review surveys the complexity involved in spinal ECM modifications, discusses new ECM-based combinatorial strategies, and explores the biomaterials evaluated in clinical trials, which hope to introduce new treatments that enhance recovery after SCI. These topics will incorporate oxidative species, which are both beneficial and harmful in reparative and regenerative processes after SCI, and not often assessed in pertinent literature. Antioxid. Redox Signal. 37, 184-207.
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Affiliation(s)
- Jonathon Chon Teng Chio
- Department of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Nayaab Punjani
- Department of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Nader Hejrati
- Department of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Canada
| | - Mohammad-Masoud Zavvarian
- Department of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada
| | - James Hong
- Department of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Canada
| | - Michael G Fehlings
- Department of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Canada.,Institute of Medical Science, University of Toronto, Toronto, Canada.,Department of Surgery and Spine Program, University of Toronto, Toronto, Canada
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2
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Kolos EA, Korzhevskii DE. Age-Related Changes in Microglia of the Rat Spinal Cord. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022040172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Pannese E. Quantitative, structural and molecular changes in neuroglia of aging mammals: A review. Eur J Histochem 2021; 65. [PMID: 34346664 PMCID: PMC8239453 DOI: 10.4081/ejh.2021.3249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/27/2021] [Indexed: 01/06/2023] Open
Abstract
The neuroglia of the central and peripheral nervous systems undergo numerous changes during normal aging. Astrocytes become hypertrophic and accumulate intermediate filaments. Oligodendrocytes and Schwann cells undergo alterations that are often accompanied by degenerative changes to the myelin sheath. In microglia, proliferation in response to injury, motility of cell processes, ability to migrate to sites of neural injury, and phagocytic and autophagic capabilities are reduced. In sensory ganglia, the number and extent of gaps between perineuronal satellite cells – that leave the surfaces of sensory ganglion neurons directly exposed to basal lamina – increase significantly. The molecular profiles of neuroglia also change in old age, which, in view of the interactions between neurons and neuroglia, have negative consequences for important physiological processes in the nervous system. Since neuroglia actively participate in numerous nervous system processes, it is likely that not only neurons but also neuroglia will prove to be useful targets for interventions to prevent, reverse or slow the behavioral changes and cognitive decline that often accompany senescence.
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Affiliation(s)
- Ennio Pannese
- Emeritus, Full Professor of Normal Human Anatomy and Neurocytology at the University of Milan.
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4
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Höpfinger A, Berghoff M, Karrasch T, Schmid A, Schäffler A. Systematic Quantification of Neurotrophic Adipokines RBP4, PEDF, and Clusterin in Human Cerebrospinal Fluid and Serum. J Clin Endocrinol Metab 2021; 106:e2239-e2250. [PMID: 33484131 DOI: 10.1210/clinem/dgaa983] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Indexed: 02/08/2023]
Abstract
CONTEXT Data on the presence/quantification of the neurotrophic adipokines retinol-binding protein-4 (RBP4), clusterin, and pigment epithelium-derived factor (PEDF) in human cerebrospinal fluid (CSF) are scarce and migration of these adipokines across of the blood-brain barrier (BBB) is uncertain. OBJECTIVE This work aimed to quantify RBP4, PEDF, and clusterin in paired serum and CSF samples of patients undergoing neurological evaluation. METHODS A total of 268 patients (109 male, 159 female) were included. Adipokine serum and CSF concentrations were measured by enzyme-linked immunosorbent assay in duplicate. RESULTS RBP4 was abundant in serum (mean, 31.9 ± 24.2 μg/mL). The serum concentrations were approximately 145 times higher than in CSF (CSF to serum RBP4 ratio, 8.2 ± 4.3 × 10-3). PEDF was detectable in serum (mean, 30.2 ± 11.7 μg/mL) and concentrations were approximately 25 times higher than in CSF (CSF to serum PEDF ratio, 42.3 ± 15.6 × 10-3). Clusterin serum concentrations were abundant with mean levels of 346.0 ± 114.6 μg/mL, which were approximately 40 times higher than CSF levels (CSF to serum clusterin ratio, 29.6 ± 23.4 × 10-3). RBP4 and PEDF serum levels correlated positively with CSF levels, which were increased in overweight/obese patients and in type 2 diabetic patients. The CSF concentrations of all 3 adipokines increased with BBB dysfunction. RBP4 in CSF correlated positively with inflammatory parameters. In detail, only RBP4 showed the kinetics and associations that are mandatory for a putative mediator of the fat-brain axis. CONCLUSION RBP4, PEDF, and clusterin are permeable to the BBB and increase with the measure of BBB dysfunction. RBP4 represents an inflammatory neurotrophic adipokine and is a promising mediator of the fat-brain axis.
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Affiliation(s)
- Alexandra Höpfinger
- Department of Internal Medicine III, Giessen University Hospital, Gießen, Germany
| | - Martin Berghoff
- Department of Neurology, Giessen University Hospital, Gießen, Germany
| | - Thomas Karrasch
- Department of Internal Medicine III, Giessen University Hospital, Gießen, Germany
| | - Andreas Schmid
- Department of Internal Medicine III, Giessen University Hospital, Gießen, Germany
| | - Andreas Schäffler
- Department of Internal Medicine III, Giessen University Hospital, Gießen, Germany
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5
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Kolos EA, Korzhevskii DE. Spinal Cord Microglia in Health and Disease. Acta Naturae 2020; 12:4-17. [PMID: 32477594 PMCID: PMC7245960 DOI: 10.32607/actanaturae.10934] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 11/09/2019] [Indexed: 12/11/2022] Open
Abstract
The review summarizes data of recent experimental studies on spinal microglia, the least explored cells of the spinal cord. It focuses on the origin and function of microglia in mammalian spinal cord embryogenesis. The main approaches to the classification of microgliocytes based on their structure, function, and immunophenotypic characteristics are analyzed. We discuss the results of studies conducted on experimental models of spinal cord diseases such as multiple sclerosis, amyotrophic lateral sclerosis, systemic inflammation, and some others, with special emphasis on the key role of microglia in the pathogenesis of these diseases. The review highlights the need to detect the new microglia-specific marker proteins expressed at all stages of ontogeny. New sensitive and selective microglial markers are necessary in order to improve identification of spinal cord microgliocytes in normal and pathological conditions. Possible morphometric methods to assess the functional activity of microglial cells are presented.
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Affiliation(s)
- E. A. Kolos
- Institute of Experimental Medicine, St. Petersburg, 197376 Russia
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6
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Nordengen K, Kirsebom BE, Henjum K, Selnes P, Gísladóttir B, Wettergreen M, Torsetnes SB, Grøntvedt GR, Waterloo KK, Aarsland D, Nilsson LNG, Fladby T. Glial activation and inflammation along the Alzheimer's disease continuum. J Neuroinflammation 2019; 16:46. [PMID: 30791945 PMCID: PMC6383268 DOI: 10.1186/s12974-019-1399-2] [Citation(s) in RCA: 145] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 01/07/2019] [Indexed: 02/08/2023] Open
Abstract
Background Neuronal and glial cell interaction is essential for synaptic homeostasis and may be affected in Alzheimer’s disease (AD). We measured cerebrospinal fluid (CSF) neuronal and glia markers along the AD continuum, to reveal putative protective or harmful stage-dependent patterns of activation. Methods We included healthy controls (n = 36) and Aβ-positive (Aβ+) cases (as defined by pathological CSF amyloid beta 1-42 (Aβ42)) with either subjective cognitive decline (SCD, n = 19), mild cognitive impairment (MCI, n = 39), or AD dementia (n = 27). The following CSF markers were measured: a microglial activation marker—soluble triggering receptor expressed on myeloid cells 2 (sTREM2), a marker of microglial inflammatory reaction—monocyte chemoattractant protein-1 (MCP-1), two astroglial activation markers—chitinase-3-like protein 1 (YKL-40) and clusterin, a neuron-microglia communication marker—fractalkine, and the CSF AD biomarkers (Aβ42, phosphorylated tau (P-tau), total tau (T-tau)). Using ANOVA with planned comparisons, or Kruskal-Wallis tests with Dunn’s pairwise comparisons, CSF levels were compared between clinical groups and between stages of biomarker severity using CSF biomarkers for classification based on amyloid pathology (A), tau pathology (T), and neurodegeneration (N) giving rise to the A/T/N score. Results Compared to healthy controls, sTREM2 was increased in SCD (p < .01), MCI (p < .05), and AD dementia cases (p < .001) and increased in AD dementia compared to MCI cases (p < .05). MCP-1 was increased in MCI (p < .05) and AD dementia compared to both healthy controls (p < .001) and SCD cases (p < .01). YKL-40 was increased in dementia compared to healthy controls (p < .01) and MCI (p < .05). All of the CSF activation markers were increased in subjects with pathological CSF T-tau (A+T−N+ and A+T+N+), compared to subjects without neurodegeneration (A−T−N− and A+T−N−). Discussion Microglial activation as indicated by increased sTREM2 is present already at the preclinical SCD stage; increased MCP-1 and astroglial activation markers (YKL-40 and clusterin) were noted only at the MCI and AD dementia stages, respectively, and in Aβ+ cases (A+) with pathological T-tau (N+). Possible different effects of early and later glial activation need to be explored. Electronic supplementary material The online version of this article (10.1186/s12974-019-1399-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kaja Nordengen
- Department of Neurology, Akershus University Hospital, P.B. 1000, N-1478, Lørenskog, Norway.
| | - Bjørn-Eivind Kirsebom
- Department of Neurology, University Hospital of North Norway, Tromsø, Norway.,Department of Psychology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Kristi Henjum
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Per Selnes
- Department of Neurology, Akershus University Hospital, P.B. 1000, N-1478, Lørenskog, Norway
| | - Berglind Gísladóttir
- Department of Neurology, Akershus University Hospital, P.B. 1000, N-1478, Lørenskog, Norway.,Clinical Molecular Biology (EpiGen), Medical Division, Akershus University Hospital and University of Oslo, Oslo, Norway
| | - Marianne Wettergreen
- Department of Neurology, Akershus University Hospital, P.B. 1000, N-1478, Lørenskog, Norway.,Clinical Molecular Biology (EpiGen), Medical Division, Akershus University Hospital and University of Oslo, Oslo, Norway
| | - Silje Bøen Torsetnes
- Department of Neurology, Akershus University Hospital, P.B. 1000, N-1478, Lørenskog, Norway.,Clinical Molecular Biology (EpiGen), Medical Division, Akershus University Hospital and University of Oslo, Oslo, Norway
| | - Gøril Rolfseng Grøntvedt
- Department of Neurology and Clinical Neurophysiology, University Hospital of Trondheim, Trondheim, Norway
| | - Knut K Waterloo
- Department of Neurology, University Hospital of North Norway, Tromsø, Norway
| | - Dag Aarsland
- Centre for Age-Related Medicine, Stavanger University Hospital, Stavanger, Norway.,Department of Old Age Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Lars N G Nilsson
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Tormod Fladby
- Department of Neurology, Akershus University Hospital, P.B. 1000, N-1478, Lørenskog, Norway.,Institute of Clinical Medicine, Campus Ahus, University of Oslo, Oslo, Norway
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7
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Herskovits AZ, Hunter TA, Maxwell N, Pereira K, Whittaker CA, Valdez G, Guarente LP. SIRT1 deacetylase in aging-induced neuromuscular degeneration and amyotrophic lateral sclerosis. Aging Cell 2018; 17:e12839. [PMID: 30295421 PMCID: PMC6260920 DOI: 10.1111/acel.12839] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 07/20/2018] [Accepted: 08/07/2018] [Indexed: 01/28/2023] Open
Abstract
SIRT1 is an NAD+ -dependent deacetylase that functions in a variety of cells and tissues to mitigate age-associated diseases. However, it remains unknown if SIRT1 also acts to prevent pathological changes that accrue in motor neurons during aging and amyotrophic lateral sclerosis (ALS). In this study, we show that SIRT1 expression decreases in the spinal cord of wild-type mice during normal aging. Using mouse models either overexpressing or lacking SIRT1 in motor neurons, we found that SIRT1 slows age-related degeneration of motor neurons' presynaptic sites at neuromuscular junctions (NMJs). Transcriptional analysis of spinal cord shows an overlap of greater than 90% when comparing alterations during normal aging with changes during ALS, revealing a substantial upregulation in immune and inflammatory response genes and a downregulation of synaptic transcripts. In addition, overexpressing SIRT1 in motor neurons delays progression to end-stage disease in high copy SOD1G93A mice. Thus, our findings suggest that there are parallels between ALS and aging, and interventions to impede aging may also slow the progression of this devastating disease.
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Affiliation(s)
- Adrianna Z. Herskovits
- Department of PathologyBeth Israel Deaconess Medical Center, Harvard Medical SchoolBostonMassachusetts
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMassachusetts
| | - Tegan A. Hunter
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMassachusetts
- University of Miami Miller School of MedicineMiamiFlorida
| | - Nicholas Maxwell
- Virginia Tech Carillion Research Institute Virginia TechRoanokeVirginia
| | - Katherine Pereira
- Virginia Tech Carillion Research Institute Virginia TechRoanokeVirginia
| | - Charles A. Whittaker
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMassachusetts
| | - Gregorio Valdez
- Virginia Tech Carillion Research Institute Virginia TechRoanokeVirginia
- Department of Biological SciencesVirginia TechBlacksburgVirginia
| | - Leonard P. Guarente
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMassachusetts
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8
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Krishnan VS, Shavlakadze T, Grounds MD, Hodgetts SI, Harvey AR. Age-related loss of VGLUT1 excitatory, but not VGAT inhibitory, immunoreactive terminals on motor neurons in spinal cords of old sarcopenic male mice. Biogerontology 2018; 19:385-399. [DOI: 10.1007/s10522-018-9765-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/04/2018] [Indexed: 12/13/2022]
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9
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Streit WJ, Xue QS. Microglia in dementia with Lewy bodies. Brain Behav Immun 2016; 55:191-201. [PMID: 26518296 DOI: 10.1016/j.bbi.2015.10.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 11/27/2022] Open
Abstract
Microglial activation (neuroinflammation) is often cited as a pathogenic factor in the development of neurodegenerative diseases. However, there are significant caveats associated with the idea that inflammation directly causes either α-synuclein pathology or neurofibrillary degeneration (NFD). We have performed immunohistochemical studies on microglial cells in five cases of dementia with Lewy bodies (DLB), median age 87, and nine cases of non-demented (ND) controls, median age 74, using tissue samples from the temporal lobe and the superior frontal gyrus. Three different antibodies known to label microglia and macrophages were employed: iba1, anti-CD68, and anti-ferritin. All DLB cases showed both α-synuclein pathology (Lewy bodies and neurites) and NFD ranging from Braak stage II to IV. In contrast, all controls were devoid of α-synuclein pathology but did show NFD ranging from Braak stage I to III. Using iba1 labeling, our current results show a notable absence of activated microglia in all cases with the exception of two controls that showed small focal areas of microglial activation and macrophage formation. Both iba1 and ferritin antibodies revealed a mixture of ramified and dystrophic microglial cells throughout the regions examined, and there were no measurable differences in the prevalence of dystrophic microglial cells between DLB and controls. Double-labeling for α-synuclein and iba1-positive microglia showed that cortical Lewy bodies were surrounded by both ramified and dystrophic microglial cells. We found an increase in CD68 expression in DLB cases relative to controls. Since microglial dystrophy has been linked to NFD and since it did not appear to be worse in DLB cases over controls, our findings support the idea that the additional Lewy body pathology in DLB is not the result of intensified microglial dystrophy. CD68 is likely associated with lipofuscin deposits in microglial cells which may be increased in DLB cases because of impaired proteostasis. Overall, we conclude that neurodegenerative changes in DLB are unlikely to result directly from activated microglia but rather from dysfunctional ones.
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Affiliation(s)
- Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610, USA.
| | - Qing-Shan Xue
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, FL 32610, USA
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10
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Perturbed cholesterol homeostasis in aging spinal cord. Neurobiol Aging 2016; 45:123-135. [PMID: 27459933 DOI: 10.1016/j.neurobiolaging.2016.05.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 04/28/2016] [Accepted: 05/16/2016] [Indexed: 12/14/2022]
Abstract
The spinal cord is vital for the processing of sensorimotor information and for its propagation to and from both the brain and the periphery. Spinal cord function is affected by aging, however, the mechanisms involved are not well-understood. To characterize molecular mechanisms of spinal cord aging, microarray analyses of gene expression were performed on cervical spinal cords of aging rats. Of the metabolic and signaling pathways affected, cholesterol-associated pathways were the most comprehensively altered, including significant downregulation of cholesterol synthesis-related genes and upregulation of cholesterol transport and metabolism genes. Paradoxically, a significant increase in total cholesterol content was observed-likely associated with cholesterol ester accumulation. To investigate potential mechanisms for the perturbed cholesterol homeostasis, we quantified the expression of myelin and neuroinflammation-associated genes and proteins. Although there was minimal change in myelin-related expression, there was an increase in phagocytic microglial and astrogliosis markers, particularly in the white matter. Together, these results suggest that perturbed cholesterol homeostasis, possibly as a result of increased inflammatory activation in spinal cord white matter, may contribute to impaired spinal cord function with aging.
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11
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Crain JM, Watters JJ. Microglial P2 Purinergic Receptor and Immunomodulatory Gene Transcripts Vary By Region, Sex, and Age in the Healthy Mouse CNS. ACTA ACUST UNITED AC 2015; 3. [PMID: 26949719 DOI: 10.4172/2329-8936.1000124] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Inflammatory damage in many neurodegenerative diseases is restricted to certain regions of the CNS, and while microglia have long been implicated in the pathology of many of these disorders, information comparing their gene expression in different CNS regions is lacking. Here we tested the hypothesis that the expression of purinergic receptors, estrogen receptors and other neuroprotective and pro-inflammatory genes differed among CNS regions in healthy mice. Because neurodegenerative diseases vary in incidence by sex and age, we also examined the regional distribution of these genes in male and female mice of four different ages between 21 days and 12 months. We postulated that pro-inflammatory gene expression would be higher in older animals, and lower in young adult females. We found that microglial gene expression differed across the CNS. Estrogen receptor alpha (Esr1) mRNA levels were often lower in microglia from the brainstem/spinal cord than from the cortex, whereas tumor necrosis factor alpha (Tnfα) expression was several times higher. In addition, the regional pattern of gene expression often changed with animal age; for example, no regional differences in P2X7 mRNA levels were detected in 21 day-old animals, but at 7 weeks and older, expression was highest in cerebellar microglia. Lastly, the expression of some genes was sexually dimorphic. In microglia from 12 month-old animals, mRNA levels of inducible nitric oxide synthase, but not Tnfα, were higher in females than males. These data suggest that microglial gene expression is not uniformly more pro-inflammatory in males or older animals. Moreover, microglia from CNS regions in which neuronal damage predominates in neurodegenerative disease do not generally express more pro-inflammatory genes than microglia from regions less frequently affected. This study provides an in-depth assessment of regional-, sex- and age-dependent differences in key microglial transcripts from the healthy mouse CNS.
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Affiliation(s)
- Jessica M Crain
- Program in Cellular and Molecular Biology, University of Wisconsin, Madison, WI 53706; Center for Women's Health Research, University of Wisconsin, Madison, WI 53706
| | - Jyoti J Watters
- Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53706; Program in Cellular and Molecular Biology, University of Wisconsin, Madison, WI 53706; Center for Women's Health Research, University of Wisconsin, Madison, WI 53706
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12
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Galbavy W, Kaczocha M, Puopolo M, Liu L, Rebecchi MJ. Neuroimmune and Neuropathic Responses of Spinal Cord and Dorsal Root Ganglia in Middle Age. PLoS One 2015; 10:e0134394. [PMID: 26241743 PMCID: PMC4524632 DOI: 10.1371/journal.pone.0134394] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 07/08/2015] [Indexed: 02/07/2023] Open
Abstract
Prior studies of aging and neuropathic injury have focused on senescent animals compared to young adults, while changes in middle age, particularly in the dorsal root ganglia (DRG), have remained largely unexplored. 14 neuroimmune mRNA markers, previously associated with peripheral nerve injury, were measured in multiplex assays of lumbar spinal cord (LSC), and DRG from young and middle-aged (3, 17 month) naïve rats, or from rats subjected to chronic constriction injury (CCI) of the sciatic nerve (after 7 days), or from aged-matched sham controls. Results showed that CD2, CD3e, CD68, CD45, TNF-α, IL6, CCL2, ATF3 and TGFβ1 mRNA levels were substantially elevated in LSC from naïve middle-aged animals compared to young adults. Similarly, LSC samples from older sham animals showed increased levels of T-cell and microglial/macrophage markers. CCI induced further increases in CCL2, and IL6, and elevated ATF3 mRNA levels in LSC of young and middle-aged adults. Immunofluorescence images of dorsal horn microglia from middle-aged naïve or sham rats were typically hypertrophic with mostly thickened, de-ramified processes, similar to microglia following CCI. Unlike the spinal cord, marker expression profiles in naïve DRG were unchanged across age (except increased ATF3); whereas, levels of GFAP protein, localized to satellite glia, were highly elevated in middle age, but independent of nerve injury. Most neuroimmune markers were elevated in DRG following CCI in young adults, yet middle-aged animals showed little response to injury. No age-related changes in nociception (heat, cold, mechanical) were observed in naïve adults, or at days 3 or 7 post-CCI. The patterns of marker expression and microglial morphologies in healthy middle age are consistent with development of a para-inflammatory state involving microglial activation and T-cell marker elevation in the dorsal horn, and neuronal stress and satellite cell activation in the DRG. These changes, however, did not affect the establishment of neuropathic pain.
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Affiliation(s)
- William Galbavy
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Martin Kaczocha
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Michelino Puopolo
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Lixin Liu
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Mario J Rebecchi
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
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13
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de Sousa AA, Dos Reis RR, de Lima CM, de Oliveira MA, Fernandes TN, Gomes GF, Diniz DG, Magalhães NM, Diniz CG, Sosthenes MCK, Bento-Torres J, Diniz JAP, Vasconcelos PFDC, Diniz CWP. Three-dimensional morphometric analysis of microglial changes in a mouse model of virus encephalitis: age and environmental influences. Eur J Neurosci 2015; 42:2036-50. [PMID: 25980955 DOI: 10.1111/ejn.12951] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 04/16/2015] [Accepted: 05/13/2015] [Indexed: 02/05/2023]
Abstract
Many RNA virus CNS infections cause neurological disease. Because Piry virus has a limited human pathogenicity and exercise reduces activation of microglia in aged mice, possible influences of environment and aging on microglial morphology and behavior in mice sublethal encephalitis were investigated. Female albino Swiss mice were raised either in standard (S) or in enriched (EE) cages from age 2 to 6 months (young - Y), or from 2 to 16 months (aged - A). After behavioral tests, mice nostrils were instilled with Piry-virus-infected or with normal brain homogenates. Brain sections were immunolabeled for virus antigens or microglia at 8 days post-infection (dpi), when behavioral changes became apparent, and at 20 and 40 dpi, after additional behavioral testing. Young infected mice from standard (SYPy) and enriched (EYPy) groups showed similar transient impairment in burrowing activity and olfactory discrimination, whereas aged infected mice from both environments (EAPy, SAPy) showed permanent reduction in both tasks. The beneficial effects of an enriched environment were smaller in aged than in young mice. Six-hundred and forty microglial cells, 80 from each group were reconstructed. An unbiased, stereological sampling approach and multivariate statistical analysis were used to search for microglial morphological families. This procedure allowed distinguishing between microglial morphology of infected and control subjects. More severe virus-associated microglial changes were observed in young than in aged mice, and EYPy seem to recover microglial homeostatic morphology earlier than SYPy . Because Piry-virus encephalitis outcomes were more severe in aged mice, it is suggested that the reduced inflammatory response in those individuals may aggravate encephalitis outcomes.
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Affiliation(s)
- Aline A de Sousa
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Renata R Dos Reis
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Camila M de Lima
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Marcus A de Oliveira
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | | | - Giovanni F Gomes
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Daniel G Diniz
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Nara M Magalhães
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Cristovam G Diniz
- Instituto Federal de Educação, Ciência e Tecnologia do Pará, Bragança, Pará, Brazil
| | - Marcia C K Sosthenes
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - João Bento-Torres
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - José Antonio P Diniz
- Instituto Evandro Chagas (IEC), Departamento de Arbovirologia e Febres Hemorrágicas, Ananindeua, Pará, Brazil
| | - Pedro F da C Vasconcelos
- Instituto Evandro Chagas (IEC), Departamento de Arbovirologia e Febres Hemorrágicas, Ananindeua, Pará, Brazil
| | - Cristovam Wanderley P Diniz
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil.,Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
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Craggs L, Taylor J, Slade JY, Chen A, Hagel C, Kuhlenbaeumer G, Borjesson-Hanson A, Viitanen M, Kalimo H, Deramecourt V, Oakley AE, Kalaria RN. Clusterin/Apolipoprotein J immunoreactivity is associated with white matter damage in cerebral small vessel diseases. Neuropathol Appl Neurobiol 2015; 42:194-209. [PMID: 25940137 PMCID: PMC4949672 DOI: 10.1111/nan.12248] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 04/26/2015] [Indexed: 12/14/2022]
Abstract
AIM Brain clusterin is known to be associated with the amyloid-β deposits in Alzheimer's disease (AD). We assessed the distribution of clusterin immunoreactivity in cerebrovascular disorders, particularly focusing on white matter changes in small vessel diseases. METHODS Post-mortem brain tissues from the frontal or temporal lobes of a total of 70 subjects with various disorders including cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), cerebral amyloid angiopathy (CAA) and AD were examined using immunohistochemistry and immunofluorescence. We further used immunogold electron microscopy to study clusterin immunoreactivity in extracellular deposits in CADASIL. RESULTS Immunostaining with clusterin antibodies revealed strong localization in arterioles and capillaries, besides cortical neurones. We found that clusterin immunostaining was significantly increased in the frontal white matter of CADASIL and pontine autosomal dominant microangiopathy and leukoencephalopathy subjects. In addition, clusterin immunostaining correlated with white matter pathology severity scores. Immunostaining in axons ranged from fine punctate deposits in single axons to larger confluent areas with numerous swollen axon bulbs, similar to that observed with known axon damage markers such as non-phosphorylated neurofilament H and the amyloid precursor protein. Immunofluorescence and immunogold electron microscopy experiments showed that whereas clusterin immunoreactivity was closely associated with vascular amyloid-β in CAA, it was lacking within the granular osmiophilic material immunolabelled by NOTCH3 extracelluar domain aggregates found in CADASIL. CONCLUSIONS Our results suggest a wider role for clusterin associated with white matter damage in addition to its ability to chaperone proteins for clearance via the perivascular drainage pathways in several disease states.
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Affiliation(s)
- Lucinda Craggs
- Neurovascular Research Group, Institute for Ageing & Health, Newcastle University, Newcastle Upon Tyne, UK
| | - Julie Taylor
- Neurovascular Research Group, Institute for Ageing & Health, Newcastle University, Newcastle Upon Tyne, UK
| | - Janet Y Slade
- Neurovascular Research Group, Institute for Ageing & Health, Newcastle University, Newcastle Upon Tyne, UK
| | - Aiqing Chen
- Neurovascular Research Group, Institute for Ageing & Health, Newcastle University, Newcastle Upon Tyne, UK
| | - Christian Hagel
- Institute of Neuropathology, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Gregor Kuhlenbaeumer
- Department of Molecular Neurobiology, Institute of Experimental Medicine, University of Kiel, Kiel, Germany
| | - Anne Borjesson-Hanson
- Institute of Neuroscience and Physiology, Salhgrenska Academy at Göteborg University, Goteborg, Sweden
| | - Matti Viitanen
- Department of Clinical Neurosciences, Karolinska Institute, Huddinge Hospital, Stockholm, Sweden
| | - Hannu Kalimo
- Department of Neuropathology, Helsinki University, Helsinki, Finland
| | - Vincent Deramecourt
- Univ Lille Nord de France, Excellence Laboratory DISTALZ, EA1046, Histology and Pathology Department, Lille University Hospital, Lille, France
| | - Arthur E Oakley
- Neurovascular Research Group, Institute for Ageing & Health, Newcastle University, Newcastle Upon Tyne, UK
| | - Raj N Kalaria
- Neurovascular Research Group, Institute for Ageing & Health, Newcastle University, Newcastle Upon Tyne, UK
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15
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Zhao Z, Xu P, Jie Z, Zuo Y, Yu B, Soong L, Sun J, Chen Y, Cai J. γδ T cells as a major source of IL-17 production during age-dependent RPE degeneration. Invest Ophthalmol Vis Sci 2014; 55:6580-9. [PMID: 25212781 PMCID: PMC4203278 DOI: 10.1167/iovs.14-15166] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
PURPOSE Chronic inflammation is a key factor contributing to the progression of age-related macular degeneration (AMD). The goals of the current study were to develop an improved mouse model with retinal pathologic features similar to those of AMD and to characterize the immunoreactive cells in the outer retina and choroid during degeneration of the retinal pigment epithelium (RPE). METHODS Mice deficient in nuclear erythroid 2-related factor 2 (Nrf2) at 12 months of age were fed a high-fat, cholesterol-rich diet for up to 16 weeks. Ocular phenotype was monitored by optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) in live animals, and was further validated by retinal histopathology. Immunofluorescence staining of either cryosections or RPE flat mounts was used to define immunoreactive cells. Flow cytometry analyses were further performed to define the subsets of intraocular T lymphocytes. RESULTS After 16 weeks on a high-fat (HF) diet, 58% of the eyes from Nrf2-/- mice had progression of retinal lesions. Major histocompatibility complex class II (MHC II)-positive microglia, FoxP3+ regulatory T cells (Tregs), and CD3+ IL-17-producing T cells were detected in either the retina or sub-RPE space. Flow cytometry analyses further revealed that most of the IL-17-producing cells were CD3+ CD4- TCRγδ+ cells. CONCLUSIONS The results suggest that the T cell-mediated immune responses played important roles in controlling the progression of AMD-like phenotype in Nrf2-deficient mice.
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Affiliation(s)
- Zhenyang Zhao
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Pei Xu
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Zuliang Jie
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Yiqin Zuo
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Bo Yu
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Yan Chen
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Jiyang Cai
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas, United States
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Repeated exposure to Ochratoxin A generates a neuroinflammatory response, characterized by neurodegenerative M1 microglial phenotype. Neurotoxicology 2014; 44:61-70. [DOI: 10.1016/j.neuro.2014.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/17/2014] [Accepted: 04/22/2014] [Indexed: 01/28/2023]
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17
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Cizkova D, Le Marrec-Croq F, Franck J, Slovinska L, Grulova I, Devaux S, Lefebvre C, Fournier I, Salzet M. Alterations of protein composition along the rostro-caudal axis after spinal cord injury: proteomic, in vitro and in vivo analyses. Front Cell Neurosci 2014; 8:105. [PMID: 24860426 PMCID: PMC4028999 DOI: 10.3389/fncel.2014.00105] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 03/24/2014] [Indexed: 12/14/2022] Open
Abstract
Based on proteomic analyses we investigated the differences of released molecules in the conditioned media (CM) from the spinal cord central lesion and adjacent rostral and caudal segments at 3, 7, and 10 days after spinal cord injury (SCI), in order to specify the molecular environment within greater extent of tissue damage. Proteins found in CM were analyzed by shot-gun MS using nanoLC coupled to an orbitrap. The results showed some specific proteins at each site of the lesion at 3days. Among the proteins from rostral and lesion segments, some are related to chemokines, cytokines or to neurogenesis factors. In contrast, proteins from caudal segments are more related to necrosis factors. The CM from each spinal segment were used in vitro, on microglial BV2 cell lines and DRGs explants, showing a lesion site-dependent impact on microglia activation and DRGs neurite outgrowth. In addition, while naive BV2 cells exhibited insignificant staining for CX3CR1 receptor, the level of CX3CR1 was strongly enhanced in some BV2 cells after their stimulation by CM collected from SCI. The molecular data might correlate with different polarization of activated microglia and macrophages along the rostro-caudal axis following acute injury. This was partially confirmed in vivo with CX3CR1 receptor, revealing higher expression in the rostral segment, with potential neuroprotective action. In addition, the neurotrophic factors released from rostral and lesion segments enhanced outgrowth of DRGs explants. Taken together these data suggest that regionalization in terms of inflammatory and neurotrophic responses may occur between rostral and caudal segments in acute SCI.
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Affiliation(s)
- Dasa Cizkova
- Laboratoire de Spectrométrie de Masse Biologique Fondamentale et Appliquée, EA 4550, FRE CNRS 3637, Université Lille 1 Villeneuve d'Ascq, France ; Laboratory of Cell and Tissue Culture, Institute of Neurobiology, Center of Excellence for Brain Research, Slovak Academy of Sciences Košice, Slovakia
| | - Françoise Le Marrec-Croq
- Laboratoire de Spectrométrie de Masse Biologique Fondamentale et Appliquée, EA 4550, FRE CNRS 3637, Université Lille 1 Villeneuve d'Ascq, France
| | - Julien Franck
- Laboratory of Cell and Tissue Culture, Institute of Neurobiology, Center of Excellence for Brain Research, Slovak Academy of Sciences Košice, Slovakia
| | - Lucia Slovinska
- Laboratoire de Spectrométrie de Masse Biologique Fondamentale et Appliquée, EA 4550, FRE CNRS 3637, Université Lille 1 Villeneuve d'Ascq, France
| | - Ivana Grulova
- Laboratory of Cell and Tissue Culture, Institute of Neurobiology, Center of Excellence for Brain Research, Slovak Academy of Sciences Košice, Slovakia
| | - Stéphanie Devaux
- Laboratoire de Spectrométrie de Masse Biologique Fondamentale et Appliquée, EA 4550, FRE CNRS 3637, Université Lille 1 Villeneuve d'Ascq, France
| | - Christophe Lefebvre
- Laboratoire de Spectrométrie de Masse Biologique Fondamentale et Appliquée, EA 4550, FRE CNRS 3637, Université Lille 1 Villeneuve d'Ascq, France
| | - Isabelle Fournier
- Laboratoire de Spectrométrie de Masse Biologique Fondamentale et Appliquée, EA 4550, FRE CNRS 3637, Université Lille 1 Villeneuve d'Ascq, France
| | - Michel Salzet
- Laboratoire de Spectrométrie de Masse Biologique Fondamentale et Appliquée, EA 4550, FRE CNRS 3637, Université Lille 1 Villeneuve d'Ascq, France
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Karalija A, Novikova LN, Kingham PJ, Wiberg M, Novikov LN. The effects of N-acetyl-cysteine and acetyl-L-carnitine on neural survival, neuroinflammation and regeneration following spinal cord injury. Neuroscience 2014; 269:143-51. [PMID: 24680856 DOI: 10.1016/j.neuroscience.2014.03.042] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 03/19/2014] [Indexed: 12/16/2022]
Abstract
Traumatic spinal cord injury induces a long-standing inflammatory response in the spinal cord tissue, leading to a progressive apoptotic death of spinal cord neurons and glial cells. We have recently demonstrated that immediate treatment with the antioxidants N-acetyl-cysteine (NAC) and acetyl-l-carnitine (ALC) attenuates neuroinflammation, induces axonal sprouting, and reduces the death of motoneurons in the vicinity of the trauma zone 4weeks after initial trauma. The objective of the current study was to investigate the effects of long-term antioxidant treatment on the survival of descending rubrospinal neurons after spinal cord injury in rats. It also examines the short- and long-term effects of treatment on apoptosis, inflammation, and regeneration in the spinal cord trauma zone. Spinal cord hemisection performed at the level C3 induced a significant loss of rubrospinal neurons 8 weeks after injury. At 2 weeks, an increase in the expression of the apoptosis-associated markers BCL-2-associated X protein (BAX) and caspase 3, as well as the microglial cell markers OX42 and ectodermal dysplasia 1 (ED1), was seen in the trauma zone. After 8 weeks, an increase in immunostaining for OX42 and the serotonin marker 5HT was detected in the same area. Antioxidant therapy reduced the loss of rubrospinal neurons by approximately 50%. Treatment also decreased the expression of BAX, caspase 3, OX42 and ED1 after 2 weeks. After 8 weeks, treatment decreased immunoreactivity for OX42, whereas it was increased for 5HT. In conclusion, this study provides further insight in the effects of treatment with NAC and ALC on descending pathways, as well as short- and long-term effects on the spinal cord trauma zone.
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Affiliation(s)
- A Karalija
- Department of Integrative Medical Biology, Section of Anatomy, Umeå University, SE-901 87 Umeå, Sweden; Department of Surgical and Perioperative Science, Section of Hand and Plastic Surgery, Umeå University, SE-901 87 Umeå, Sweden.
| | - L N Novikova
- Department of Integrative Medical Biology, Section of Anatomy, Umeå University, SE-901 87 Umeå, Sweden
| | - P J Kingham
- Department of Integrative Medical Biology, Section of Anatomy, Umeå University, SE-901 87 Umeå, Sweden
| | - M Wiberg
- Department of Integrative Medical Biology, Section of Anatomy, Umeå University, SE-901 87 Umeå, Sweden; Department of Surgical and Perioperative Science, Section of Hand and Plastic Surgery, Umeå University, SE-901 87 Umeå, Sweden
| | - L N Novikov
- Department of Integrative Medical Biology, Section of Anatomy, Umeå University, SE-901 87 Umeå, Sweden
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Noyan-Ashraf MH, Sadeghinejad Z, Juurlink BHJ. Dietary approach to decrease aging-related CNS inflammation. Nutr Neurosci 2013; 8:101-10. [PMID: 16053242 DOI: 10.1080/10284150500069470] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We demonstrate that the spontaneously hypertensive rat stroke-prone rat (SHRsp) undergoes premature aging of the CNS compared to the related normotensive Wistar Kyoto rat (WKY) as demonstrated by presence of activated microglia/macrophages, increased expression of inducible nitric oxide synthase and increased astrogliosis. We tested the hypothesis that dietary intake of phase 2 protein inducers would decrease these aging-associated degenerative changes. The source of dietary phase 2 protein inducers was dried broccoli sprouts of a cultivar containing high amounts of glucoraphanin that gives rise to phase 2 protein-inducing isothiocyanate sulforaphane. This diet significantly decreased the aging-related degenerative changes in the SHRsp CNS. We conclude that modest changes in diet may have profound effects on the aging CNS.
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Affiliation(s)
- M H Noyan-Ashraf
- Department of Anatomy and Cell Biology, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK, Canada S7N 5E5
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20
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Dimitrijević M, Stanojević S, Kuštrimović N, Mitić K, Vujić V, Aleksić I, Radojević K, Leposavić G. The influence of aging and estradiol to progesterone ratio on rat macrophage phenotypic profile and NO and TNF-α production. Exp Gerontol 2013; 48:1243-54. [PMID: 23850866 DOI: 10.1016/j.exger.2013.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/17/2013] [Accepted: 07/02/2013] [Indexed: 11/17/2022]
Abstract
The phenotype and function of tissue macrophages substantially depend on the cellular milieu and biological effector molecules, such as steroid hormones, to which they are exposed. Furthermore, in female rats, aging is associated with the altered macrophage functioning and the increased estrogen level is followed by a decrease in that of progesterone. Therefore, the present study aimed to investigate the influence of estradiol/progesterone balance on rat macrophage function and phenotype throughout whole adult lifespan. We ovariectomized rats at the late prepubertal age or at the very end of reproductive lifespan, and examined the expression of ED2 (CD163, a marker of mature resident macrophages related to secretion of inflammatory mediators) on peritoneal macrophages and their ability to produce TNF-α and NO upon LPS-stimulation at different age points. In addition, to delineate direct and indirect effects of estrogen, we assessed the in vitro influence of different concentrations of 17β-estradiol on LPS-induced macrophage TNF-α and NO production. Results showed that: (a) the low frequency of ED2(high) cells amongst peritoneal macrophages of aged rats was accompanied with the reduced TNF-α, but not NO production; (b) estradiol level gradually increased following ovariectomy; (c) macrophage ED2 expression and TNF-α production were dependent on estradiol/progesterone balance and they changed in the same direction; (d) changes in estradiol/progesterone balance differentially affected macrophages TNF-α and NO production; and (e) estradiol exerted pro-inflammatory and anti-inflammatory effects on macrophages in vivo and in vitro, respectively. Overall, our study discloses that estradiol/progesterone balance contributes to the fine-tuning of rat macrophage secretory capacity, and adds to a better understanding of the ovarian steroid hormone role in the regulation of macrophage function, and its significance for the age-associated changes in innate immunity.
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Affiliation(s)
- Mirjana Dimitrijević
- Institute of Virology, Vaccines and Sera, "Torlak", Immunology Research Center "Branislav Janković", Vojvode Stepe 458, 11152 Belgrade, Serbia.
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21
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Viana L, Lima C, Oliveira M, Borges R, Cardoso T, Almeida I, Diniz D, Bento-Torres J, Pereira A, Batista-de-Oliveira M, Lopes A, Silva R, Abadie-Guedes R, Amâncio dos Santos A, Lima D, Vasconcelos P, Cunningham C, Guedes R, Picanço-Diniz C. Litter size, age-related memory impairments, and microglial changes in rat dentate gyrus: Stereological analysis and three dimensional morphometry. Neuroscience 2013; 238:280-96. [DOI: 10.1016/j.neuroscience.2013.02.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/12/2013] [Accepted: 02/12/2013] [Indexed: 10/27/2022]
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Administration of glucosylceramide ameliorated the memory impairment in aged mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:824120. [PMID: 23690856 PMCID: PMC3638615 DOI: 10.1155/2013/824120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 03/06/2013] [Indexed: 12/27/2022]
Abstract
The function and the role of glucosylceramide have not been well studied in the central nervous system. This study was aimed to investigate the possible roles of glucosylceramide in memory function in aged mice. Glucosylceramide (50 mg/kg, p.o.) showed memory enhancing activity after 3-month treatment in the aged mice (C56BL/6, 18–20 months old) through Y-maze, novel objective test, and Morris water maze test. Long-term treatment of glucosylceramide decreased the expression of iNOS and COX-2 in the brain of aged mice. The LPS-induced mRNA level of iNOS, COX-2, IL-1β, and TNF-α was reduced by the acute treatment with glucosylceramide in adult mice. These results suggest that glucosylceramide plays an important role in anti-inflammatory and memory enhancement, and it could be a potential new therapeutic agent for the treatment of neurodegenerative diseases such as Alzheimer's disease.
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Farso M, Ménard C, Colby-Milley J, Quirion R. Immune marker CD68 correlates with cognitive impairment in normally aged rats. Neurobiol Aging 2013; 34:1971-6. [PMID: 23523271 DOI: 10.1016/j.neurobiolaging.2013.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 02/08/2013] [Accepted: 02/15/2013] [Indexed: 11/16/2022]
Abstract
The relationship between heightened neuroinflammation and cognitive decline in the normally aged brain is still debatable, as most data are derived from insult-related models. Accordingly, the aim of the current study was to determine whether a link could be established for 2 immune markers at the post-transcriptional level; CD68 and MHC-II, in a normally aged (24-month-old) rat population discriminated for their learning abilities. Using the Morris Water Maze (MWM) task, aged rats were divided into aged learning-impaired (AI) or -unimpaired (AU) groups. Western immunoblots of hippocampal tissue revealed a significant increase of CD68 in AI rats compared to the AU group. Moreover, up-regulated CD68 expression correlated with increased latency times in the MWM task. Immunofluorescence for CD68 revealed intense staining in the white matter regions and CA3 subregion of the hippocampus in the AI group. Despite expression of MHC-II in the AI group, no correlation was found. Overall, these data suggest that CD68 could play a role associated with cognitive decline in a subgroup of the normally aged population.
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Affiliation(s)
- Mark Farso
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montréal, Québec, Canada
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Borre Y, Sir V, de Kivit S, Westphal KG, Olivier B, Oosting RS. Minocycline restores spatial but not fear memory in olfactory bulbectomized rats. Eur J Pharmacol 2012; 697:59-64. [DOI: 10.1016/j.ejphar.2012.09.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Revised: 08/27/2012] [Accepted: 09/06/2012] [Indexed: 12/22/2022]
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Hart AD, Wyttenbach A, Hugh Perry V, Teeling JL. Age related changes in microglial phenotype vary between CNS regions: grey versus white matter differences. Brain Behav Immun 2012; 26:754-65. [PMID: 22155499 PMCID: PMC3381227 DOI: 10.1016/j.bbi.2011.11.006] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 11/18/2011] [Accepted: 11/23/2011] [Indexed: 12/22/2022] Open
Abstract
Subtle regional differences in microglial phenotype exist in the adult mouse brain. We investigated whether these differences were amplified during ageing and following systemic challenge with lipopolysaccharide (LPS). We studied microglial morphology and phenotype in young (4mo) and aged (21mo) C57/BL6 mice using immunohistochemistry and quantified the expression levels of surface molecules on microglia in white and grey matter along the rostral-caudal neuraxis. We detected significant regional, age dependent differences in microglial phenotypes, with the microglia of white matter and caudal areas of the CNS exhibiting greater upregulation of CD11b, CD68, CD11c, F4/80 and FcγRI than grey matter and rostral CNS areas. Upregulation of CD11c with age was restricted to the white matter, as was the appearance of multinucleated giant cells. Systemic LPS caused a subtle upregulation of FcγRI after 24 h, but the other markers examined were not affected. Burrowing behaviour and static rod assays were used to assess hippocampal and cerebellar integrity. Aged mice exhibited exaggerated and prolonged burrowing deficits following systemic LPS injection, while in the absence of an inflammatory challenge aged mice performed significantly worse than young mice in the static rod test. Taken together, these findings show that the effects of age on microglial phenotype and functional integrity vary significantly between CNS compartments, as do, albeit to a lesser extent, the effects of systemic LPS.
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Affiliation(s)
- Adam D. Hart
- Corresponding author. Address: Centre for Biological Sciences, University of Southampton, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK. Fax: +44(0) 2380 795332.
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Song F, Poljak A, Crawford J, Kochan NA, Wen W, Cameron B, Lux O, Brodaty H, Mather K, Smythe GA, Sachdev PS. Plasma apolipoprotein levels are associated with cognitive status and decline in a community cohort of older individuals. PLoS One 2012; 7:e34078. [PMID: 22701550 PMCID: PMC3372509 DOI: 10.1371/journal.pone.0034078] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 02/21/2012] [Indexed: 11/29/2022] Open
Abstract
Objectives Apolipoproteins have recently been implicated in the etiology of Alzheimer’s disease (AD). In particular, Apolipoprotein J (ApoJ or clusterin) has been proposed as a biomarker of the disease at the pre-dementia stage. We examined a group of apolipoproteins, including ApoA1, ApoA2, ApoB, ApoC3, ApoE, ApoH and ApoJ, in the plasma of a longitudinal community based cohort. Methods 664 subjects (257 with Mild Cognitive Impairment [MCI] and 407 with normal cognition), mean age 78 years, from the Sydney Memory and Aging Study (MAS) were followed up over two years. Plasma apolipoprotein levels at baseline (Wave 1) were measured using a multiplex bead fluorescence immunoassay technique. Results At Wave 1, MCI subjects had lower levels of ApoA1, ApoA2 and ApoH, and higher levels of ApoE and ApoJ, and a higher ApoB/ApoA1 ratio. Carriers of the apolipoprotein E ε4 allele had significantly lower levels of plasma ApoE, ApoC3 and ApoH and a significantly higher level of ApoB. Global cognitive scores were correlated positively with ApoH and negatively with ApoJ levels. ApoJ and ApoE levels were correlated negatively with grey matter volume and positively with cerebrospinal fluid (CSF) volume on MRI. Lower ApoA1, ApoA2 and ApoH levels, and higher ApoB/ApoA1 ratio, increased the risk of cognitive decline over two years in cognitively normal individuals. ApoA1 was the most significant predictor of decline. These associations remained after statistically controlling for lipid profile. Higher ApoJ levels predicted white matter atrophy over two years. Conclusions Elderly individuals with MCI have abnormal apolipoprotein levels, which are related to cognitive function and volumetric MRI measures cross-sectionally and are predictive of cognitive impairment in cognitively normal subjects. ApoA1, ApoH and ApoJ are potential plasma biomarkers of cognitive decline in non-demented elderly individuals.
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Affiliation(s)
- Fei Song
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
- Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, Australia
| | - Anne Poljak
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
- Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, Australia
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - John Crawford
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Nicole A. Kochan
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Wei Wen
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Barbara Cameron
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Ora Lux
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
| | - Henry Brodaty
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
- Dementia Collaborative Research Centre, University of New South Wales, Sydney, Australia
| | - Karen Mather
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
| | - George A. Smythe
- Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, Australia
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Perminder S. Sachdev
- Brain and Aging Research Program, University of New South Wales, Sydney, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
- * E-mail:
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Propidium iodide staining: a new application in fluorescence microscopy for analysis of cytoarchitecture in adult and developing rodent brain. Micron 2012; 43:1031-8. [PMID: 22579654 DOI: 10.1016/j.micron.2012.04.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Revised: 04/01/2012] [Accepted: 04/10/2012] [Indexed: 11/20/2022]
Abstract
Immunohistochemical visualization of antigens in specimen has evolved to an indispensable technique in biomedical research for investigations of cell morphology and pathology both in bright field and fluorescence microscopy. While there are couple of staining methods that reveal entire cytoarchitecture in bright field microscopy such as Nissl or hemalaun-eosin, there are still limitations in visualizations of cytoarchitecture in fluorescence microscopy. The present study reports a simple staining method that provides the required illustration of cell allocations and cellular composition in fluorescence microscopy in adult and in developing rodent central nervous system using the fluorophore propidium iodide (PI, 5μg/mL). PI is a well-accepted marker for degenerating cells when applied prior to fixation (pre-fixation PI staining). Here, PI was added to the sections after the fixation (post-fixation PI staining). This revised labeling procedure led to similar cytoarchitectural staining patterns in fluorescence microscopy as observed with hemalaun in bright field microscopy. This finding was proven in organotypic hippocampal slice cultures (OHSC) and brain sections obtained from different postnatal developmental stages. Excitotoxically lesioned OHSC subjected to pre-fixation PI staining merely showed brightly labeled condensed nuclei of degenerating neurons. In contrast, post-fixation PI staining additionally revealed extensive labeling of neuronal cell bodies and glial cells within the OHSC, thus allowing visualization of stratification of neuronal layers and cell morphology. Furthermore, post-fixation PI staining was combined with NeuN, calbindin, calretinin, glial fibrillary acidic protein or Griffonia simplicifolia isolectin B4 (IB(4)) in post natal (p1 and p9) and adult rats. In early post-natal brain sections almost all mentioned cellular markers led to an incomplete staining of the native cell organization and resulted in an inaccurate estimation of cell morphology when compared to adult brains. In contrast, post-fixation PI staining allowed investigation of the whole cytoarchitecture independent of the developmental stage. Taken together, post-fixation PI staining provides a detailed insight in the morphology of both developing and adult brain tissues in fluorescence microscopy.
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Abstract
Over the years it has become evident that the immune system can affect the function of the central nervous system (CNS), including altering cognitive processes. The impact of immune activation on the CNS is particularly important for aged individuals, as the brain's resident immune cells, microglia, acquire a pro-inflammatory profile. The low-grade chronic neuroinflammation that develops with normal aging likely contributes to the susceptibility to cognitive deficits and a host of age-related pathologies. Understanding why microglia show increased inflammatory activity (i.e., neuroinflammation) and identifying effective treatments to reduce microglia activation is expected to have beneficial effects on cognitive performance and measures of neural plasticity. However, microglia also promote regeneration after injury. Therefore, effective treatments must dampen inflammatory activity while preserving microglia's neuroprotective function. Discovering factors that induce neuroinflammation and investigating potential preventative therapies is expected to uncover the ways of maintaining normal microglia activity in the aged brain.
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Affiliation(s)
- Rachel A Kohman
- Department of Psychology, University of Illinois at Urbana-Champaign, Beckman Institute, Urbana, IL, USA.
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29
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Bejarano-Escobar R, Holguín-Arévalo MS, Montero JA, Francisco-Morcillo J, Martín-Partido G. Macrophage and microglia ontogeny in the mouse visual system can be traced by the expression of Cathepsins B and D. Dev Dyn 2011; 240:1841-55. [PMID: 21648018 DOI: 10.1002/dvdy.22673] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2011] [Indexed: 01/11/2023] Open
Abstract
Here, we show a detailed chronotopographical analysis of cathepsin B and D expression during development of the mouse visual system. Both proteases were detected in large rounded/ameboid cells usually located in close relationship with prominent sites of extensive physiological cell death. In concordance with their morphological features and topographical distribution, we demonstrate that expressing cells corresponded with macrophages and microglial precursors. We found that as microglial precursors differentiated the expression of both cathepsins was down-regulated. Of interest, cathepsin B and D transcripts were never observed in degenerating cells. Our findings point to a role for cathepsin D and B in cell debris degradation after apoptotic processes rather than promoting cell death, as proposed for other developmental models. Additionally their pattern of expression suggests a role in the maturation of the microglial precursors.
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Affiliation(s)
- Ruth Bejarano-Escobar
- Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
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30
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Damani MR, Zhao L, Fontainhas AM, Amaral J, Fariss RN, Wong WT. Age-related alterations in the dynamic behavior of microglia. Aging Cell 2011; 10:263-76. [PMID: 21108733 DOI: 10.1111/j.1474-9726.2010.00660.x] [Citation(s) in RCA: 328] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Microglia, the primary resident immune cells of the central nervous system (CNS), exhibit dynamic behavior involving rapid process motility and cellular migration that is thought to underlie key functions of immune surveillance and tissue repair. Although age-related changes in microglial activation have been implicated in the pathogenesis of neurodegenerative diseases of aging, how dynamic behavior in microglia is influenced by aging is not fully understood. In this study, we employed live imaging of retinal microglia in situ to compare microglial morphology and behavioral dynamics in young and aged animals. We found that aged microglia in the resting state have significantly smaller and less branched dendritic arbors, and also slower process motilities, which probably compromise their ability to survey and interact with their environment continuously. We also found that dynamic microglial responses to injury were age-dependent. While young microglia responded to extracellular ATP, an injury-associated signal, by increasing their motility and becoming more ramified, aged microglia exhibited a contrary response, becoming less dynamic and ramified. In response to laser-induced focal tissue injury, aged microglia demonstrated slower acute responses with lower rates of process motility and cellular migration compared with young microglia. Interestingly, the longer term response of disaggregation from the injury site was retarded in aged microglia, indicating that senescent microglial responses, while slower to initiate, are more sustained. Together, these altered features of microglial behavior at rest and following injury reveal an age-dependent dysregulation of immune response in the CNS that may illuminate microglial contributions to age-related neuroinflammatory degeneration.
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Affiliation(s)
- Mausam R Damani
- Unit on Neuron-Glia Interactions in Retinal Disease Mechanisms of Disease Section Biological Imaging Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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31
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Jordan WH, Young JK, Hyten MJ, Hall DG. Preparation and Analysis of the Central Nervous System. Toxicol Pathol 2010; 39:58-65. [PMID: 21139057 DOI: 10.1177/0192623310391480] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
For many pathologists, neuropathology is intimidating. Practical approaches for nervous tissue histologic evaluations to meet both routine and advanced study designs can lead to rewarding neuropathology efforts. Cost-effective, high-quality histologic evaluations can occur if animals are exsanguinated quickly, brains removed carefully to maintain structural integrity and avoid dark neuron artifact, immersion-fixed quickly and thoroughly, and trimmed and processed to consistently survey multiple areas. While brightfield examination of H&E-stained sections is generally sufficient for survey evaluations, epifluorescent assessment of neuronal autofluorescence facilitates recognition of neurodegeneration in H&E-stained sections. Fluoro-Jade B or specialized immunohistochemical stains may be required to answer specific questions. Evaluations require that both technical staff and pathologists have a working knowledge of a few easily identified neuroanatomic landmarks and familiarity with use of a detailed brain atlas. At least four coronal sections should be routinely surveyed from young adult rats, with evaluation of comparable areas in other laboratory animal species. This number should be at least doubled if there is reason to suspect morphologic changes in the CNS. This article focuses on technical details of efficient specimen preparation for neuropathologic evaluations involving relatively large numbers of rodents, as well as a practical approach to basic neuroanatomic site identification.
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Affiliation(s)
| | | | | | - D. Greg Hall
- Lilly Research Laboratories, Indianapolis, Indiana, USA
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32
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Moussaud S, Draheim HJ. A new method to isolate microglia from adult mice and culture them for an extended period of time. J Neurosci Methods 2010; 187:243-53. [DOI: 10.1016/j.jneumeth.2010.01.017] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 01/14/2010] [Accepted: 01/15/2010] [Indexed: 12/25/2022]
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Streit WJ, Xue QS. Life and death of microglia. J Neuroimmune Pharmacol 2009; 4:371-9. [PMID: 19680817 DOI: 10.1007/s11481-009-9163-5] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 06/30/2009] [Indexed: 01/05/2023]
Abstract
The importance of microglial cells in the maintenance of a well-functioning central nervous system (CNS) cannot be overstated. As descendants of the myelomonocytic lineage they are industrious housekeepers and watchful sentries that safeguard a homeostatic environment through a number of mechanisms designed to provide protection of fastidious neurons at all times. Microglia become particularly active after homeostasis has been perturbed by physical injury or other insults and they enter into a state of activation which is determined largely by the nature and severity of the lesion. Microglial activation is the main cellular event in acute neuroinflammation and essential for wound healing in the CNS. Recent studies from this laboratory have been focused on microglia in the aging brain and identified structural abnormalities, termed microglial dystrophy, that are consistent with cell senescence and progress to a form of accidental cell death that is marked by cytoplasmic degeneration and has been termed cytorrhexis. Cytorrhexis of microglia is infrequent in the normally aged human brain and non-detectable in aged rodents, but its occurrence increases dramatically during neurodegenerative conditions, including Alzheimer's disease (AD) in humans and motoneuron disease in transgenic rats. The identification of degenerating microglia has given rise to a novel theory of AD pathogenesis, the microglial dysfunction hypothesis, which views the loss of microglial neuroprotection as a central event in neurodegenerative disease development.
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Affiliation(s)
- Wolfgang J Streit
- Department of Neuroscience, McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL 32610, USA.
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34
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The multifaceted profile of activated microglia. Mol Neurobiol 2009; 40:139-56. [PMID: 19629762 DOI: 10.1007/s12035-009-8077-9] [Citation(s) in RCA: 204] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Accepted: 06/17/2009] [Indexed: 12/17/2022]
Abstract
Although relatively neglected previously, research efforts in the past decade or so have identified a pivotal role for glial cells in regulating neuronal function. Particular emphasis has been placed on increasing our understanding of the function of microglia because a change from the ramified "resting" state of these cells has been associated with the pathogenesis of several neurodegenerative diseases, notably Alzheimer's disease. However, it is not clear whether activation of microglia and the associated inflammatory changes play a part in triggering disease processes or whether cell activation is a response to the early changes associated with the disease. In either case, the possibility exists that modulation of microglial activation may be beneficial in some circumstances, underlying the need to pursue research in this area. The original morphological categorization of microglia by Del Rio Hortega into ameboid, ramified, and intermediate forms, must now be elaborated to encompass a functional description. The evidence which has been generated recently suggests that microglia are probably never in a "resting" state and that several intermediate transitional states, based on function and morphology, probably exist. A more complete understanding of these states and the triggers which lead to a change from one to another state, and the factors which modulate the molecular switch that determines the persistence of the "activated" state remain to be identified.
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35
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Park DH, Eve DJ, Musso J, Klasko SK, Cruz E, Borlongan CV, Sanberg PR. Inflammation and Stem Cell Migration to the Injured Brain in Higher Organisms. Stem Cells Dev 2009; 18:693-702. [DOI: 10.1089/scd.2009.0008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Dong-Hyuk Park
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida, Tampa, Florida
- Department of Neurosurgery, Korea University Medical Center, Korea University, Seoul, Korea
| | - David J. Eve
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida, Tampa, Florida
| | - James Musso
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida, Tampa, Florida
| | | | - Eduardo Cruz
- Cryopraxis, CellPraxis, BioRio, Pólo de Biotecnologia do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Cesario V. Borlongan
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida, Tampa, Florida
| | - Paul R. Sanberg
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida, Tampa, Florida
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36
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Neuroinflammatory changes increase the impact of stressors on neuronal function. Biochem Soc Trans 2009; 37:303-7. [PMID: 19143652 DOI: 10.1042/bst0370303] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In the last few years, several research groups have reported that neuroinflammation is one feature common to several neurodegenerative diseases and that similar, although perhaps less profound, neuroinflammatory changes also occur with age. Age is the greatest risk factor in many neurodegenerative diseases, and the possibility exists that the underlying age-related neuroinflammation may contribute to this increased risk. Several animal models have been used to examine this possibility, and it is now accepted that, under experimental conditions in which microglial activation is up-regulated, responses to stressors are exacerbated. In the present article, these findings are discussed and data are presented from in vitro and in vivo experiments which reveal that responses to Abeta (amyloid beta-peptide) are markedly up-regulated in the presence of LPS (lipopolysaccharide). These, and previous findings, point to a vulnerability associated with inflammation and suggest that, even though inflammation may not be the primary cause of neurodegenerative disease, its treatment may decelerate disease progression.
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37
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Wasserman JK, Yang H, Schlichter LC. Glial responses, neuron death and lesion resolution after intracerebral hemorrhage in young vs. aged rats. Eur J Neurosci 2009; 28:1316-28. [PMID: 18973558 DOI: 10.1111/j.1460-9568.2008.06442.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Intracerebral hemorrhage (ICH) usually affects older humans but almost no experimental studies have assessed aged animals. We address how aging alters inflammation, neuron death and lesion resolution after a hemorrhage in the rat striatum. In the normal aged brain, microglia displayed a 'dystrophic' phenotype, with shorter cellular processes and large gaps between adjacent cells, and there was more astrocyte reactivity. The ICH injury was monitored as hematoma volume and number of dying neurons at 1 and 3 days, and the volume of the residual lesion, ventricles and lost tissue at 28 days. Inflammation at 1 and 3 days was assessed from densities of microglia with resting vs. activated morphologies, or expressing the lysosomal marker ED1. Despite an initial delay in neuron death in aged animals, by 28 days, there was no difference in neuron density or volume of tissue lost. However, lesion resolution was impaired in aged animals and there was less compensatory ventricular expansion. At 1 day after ICH, there were fewer activated microglia/macrophages in the aged brain, but by 3 days there were more of these cells at the edge of the hematoma and in the surrounding parenchyma. In both age groups a glial limitans had developed by 3 days, but astrocyte reactivity and the spread of activated microglia/macrophages into the surrounding parenchyma was greater in the aged. These findings have important implications for efforts to reduce secondary injury after ICH and to develop anti-inflammatory therapies to treat ICH in aged humans.
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Affiliation(s)
- Jason K Wasserman
- Toronto Western Research Institute, University Health Network, Toronto Western Hospital, 399 Bathurst Street, Toronto, ON, Canada
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38
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Noyan-Ashraf MH, Sadeghinejad Z, Davies GF, Ross AR, Saucier D, Harkness TAA, Juurlink BHJ. Phase 2 protein inducers in the diet promote healthier aging. J Gerontol A Biol Sci Med Sci 2008; 63:1168-76. [PMID: 19038831 DOI: 10.1093/gerona/63.11.1168] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Oxidative stress drives many aging-associated problems. Because oxidative stress can be decreased by induction of phase 2 proteins, we hypothesized that incorporating the phase 2 protein inducer 2(3)-tert-butyl-4-hydroxyanisole (tBHA) into the diet would result in healthier aging. C57BL/6 mice were placed either on control mouse chow diet or on chow containing tBHA and were examined at 6, 12, and 18 months. Dietary tBHA resulted in the antioxidant response activation, decreased both oxidative stress and pro-inflammatory gene expression in tissues examined, counteracted the decrease in the transcription factors peroxisome proliferator-activated receptor-gamma and increase in CCAAT/enhancer binding protein-alpha levels seen in liver with aging, and was associated with mice having less weight gain, despite having no differences in food consumption, and better locomotor function. We conclude that simple changes in the diet such as incorporation of phase 2 protein inducers can have a profound influence on health and, thereby, the aging process.
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39
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Wu Z, Tokuda Y, Zhang XW, Nakanishi H. Age-dependent responses of glial cells and leptomeninges during systemic inflammation. Neurobiol Dis 2008; 32:543-51. [PMID: 18848892 DOI: 10.1016/j.nbd.2008.09.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 08/20/2008] [Accepted: 09/09/2008] [Indexed: 01/12/2023] Open
Abstract
Systemic inflammation causes the age-dependent differential glial responses, but little is known about how age influences the barrier function of leptomeninges during systemic inflammation. This study was conducted to elucidate the relationship between the glial responses and the levels of tight junction proteins, occludin and ZO-1, in adjuvant arthritis (AA) rats. In young AA rats, microglia and astrocytes localized to the proximity of the leptomeninges expressed interleukin (IL)-10 and transforming growth factor (TGF)-beta1. The level of occludin significantly increased. In middle-aged AA rats, however, glial cells expressed IL-1beta and prostaglandin E(2) (PGE(2))-synthesizing enzymes. Furthermore, occludin and ZO-1 significantly decreased, resulting in the increased permeability of leptomeninges. In the cultured leptomeningeal cells, IL-1beta and PGE(2) caused a marked loss of occludin and ZO-1, respectively. Pretreatment with IL-10 and TGF-beta1 significantly antagonized their effects. These findings establish that age strongly influences the barrier functions of the leptomeninges through the age-dependent differential glial responses during systemic inflammation.
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Affiliation(s)
- Zhou Wu
- Laboratory of Oral Aging Science, Faculty of Dental Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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40
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41
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Minogue AM, Lynch AM, Loane DJ, Herron CE, Lynch MA. Modulation of amyloid-beta-induced and age-associated changes in rat hippocampus by eicosapentaenoic acid. J Neurochem 2007; 103:914-26. [PMID: 17711425 DOI: 10.1111/j.1471-4159.2007.04848.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The age-related deficit in long-term potentiation (LTP) in the dentate gyrus is positively correlated with hippocampal concentration of the pro-inflammatory cytokine, interleukin-1beta (IL-1beta). Previous evidence also indicates that the inhibition of LTP induced by intracerebroventricular injection of amyloid-beta(1-40) (Abeta) is accompanied by increased hippocampal IL-1beta concentration and IL-1beta-stimulated signalling, specifically activation of the stress-activated protein kinase, c-jun N-terminal kinase (JNK). We considered that the underlying age-related neuroinflammation may render older rats more susceptible to Abeta administration and, to investigate this, young, middle-aged and aged rats were injected intracerebroventricularly with Abeta or vehicle. Hippocampal IL-1beta concentration, JNK phosphorylation, expression of the putative Abeta receptor, Receptor for advanced glycation end products (RAGE) and the microglial cell surface marker, CD40 were assessed. We report that Abeta inhibited LTP in a concentration-dependent manner in young rats and that this was accompanied by concentration-dependent increases in hippocampal IL-1beta and expression of phosphorylated JNK, RAGE and CD40. While 20 micromol/L Abeta exerted no significant effect on LTP in young rats, it inhibited LTP in middle-aged and aged rats and the increased vulnerability of aged rats was associated with increased IL-1beta concentration. Treatment of rats with eicosapentaenoic acid attenuated the inhibitory effect of 60 micromol/L Abeta on LTP in young rats and the effect of 20 micromol/L Abeta in middle-aged and aged rats. We present evidence which indicates that the effect of eicosapentaenoic acid may be linked with its ability to stimulate activation of peroxisome proliferator-activated receptor gamma.
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Affiliation(s)
- Aedín M Minogue
- Conway Institute of Biomedical and Biomolecular Research, University College Dublin, Belfield, Dublin, Ireland
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42
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Walczak P, Chen N, Eve D, Hudson J, Zigova T, Sanchez-Ramos J, Sanberg PR, Sanberg CD, Willing AE. Long-term cultured human umbilical cord neural-like cells transplanted into the striatum of NOD SCID mice. Brain Res Bull 2007; 74:155-63. [PMID: 17683802 PMCID: PMC2680127 DOI: 10.1016/j.brainresbull.2007.06.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 05/23/2007] [Accepted: 06/12/2007] [Indexed: 12/23/2022]
Abstract
The use of stem cells and other cells as therapies is still in its infancy. One major setback is the limited survival of the grafts, possibly due to immune rejection. Studies were therefore performed with human umbilical cord blood cells (HUCB) to determine the ability of these cells to survive in vivo and the effect of the immune response on their survival by transplantation into the normal striatum of immunodeficient NOD SCID mice. Long-term culture of HUCB cells resulted in several different populations of cells, including one that possessed fine processes and cell bodies that resembled neurons. Their neuronal phenotype was confirmed by immunohistochemical staining for the early neuronal marker TuJ1 and the potentially neural marker Nestin. Five days after cell transplantation of this neuronal phenotype, immunohistochemical staining for human mitochondria confirmed the presence of living HUCB cells in the mouse striatum, with cells localized at the site of injection, expressing early neural and neuronal markers (Nestin and TuJ1) as well as exhibiting neuronal morphology. However, no evidence of surviving cells was apparent 1 month postgrafting. The absence of signs of T cell-mediated rejection, such as CD4 and CD8 lymphocytes and minimal changes in microglia and astrocytes, suggest that cell loss was not due to a T cell-mediated immune response. In conclusion HUCB cells can survive long-term in vitro and undergo neuron-like differentiation. In mice, these cells do not survive a month. This may relate to the differentiated state of the cells transplanted into the unlesioned striatum, rather than T cell-mediated immunological rejection.
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Affiliation(s)
- Piotr Walczak
- Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Neurosurgery, University of South Florida, College of Medicine, Tampa, FL, USA
| | - Ning Chen
- Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Neurosurgery, University of South Florida, College of Medicine, Tampa, FL, USA
| | - David Eve
- Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Neurosurgery, University of South Florida, College of Medicine, Tampa, FL, USA
| | - Jennifer Hudson
- Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Neurosurgery, University of South Florida, College of Medicine, Tampa, FL, USA
| | - Tanja Zigova
- Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Neurosurgery, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Pathology and Cell Biology, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Molecular Pharmacology and Physiology, University of South Florida, College of Medicine, Tampa, FL, USA
| | - Juan Sanchez-Ramos
- Department of Neurology, University of South Florida, College of Medicine, Tampa, FL, USA
- James A. Haley VA Hospital, Tampa, FL, USA
| | - Paul R. Sanberg
- Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Neurosurgery, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Pathology and Cell Biology, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Psychiatry, University of South Florida, College of Medicine, Tampa, FL, USA
| | | | - Alison E. Willing
- Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Neurosurgery, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Pathology and Cell Biology, University of South Florida, College of Medicine, Tampa, FL, USA
- Department of Molecular Pharmacology and Physiology, University of South Florida, College of Medicine, Tampa, FL, USA
- Corresponding author at: Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida, College of Medicine, Tampa, FL, USA. Tel.: +1 813 974 7812. E-mail address: (A.E. Willing)
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43
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Edström E, Altun M, Bergman E, Johnson H, Kullberg S, Ramírez-León V, Ulfhake B. Factors contributing to neuromuscular impairment and sarcopenia during aging. Physiol Behav 2007; 92:129-35. [PMID: 17585972 DOI: 10.1016/j.physbeh.2007.05.040] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Motor disturbances and wasting of skeletal muscles (sarcopenia) causes significant impairment of daily life activities and is a major underlying cause for hospitalization in senescence. Herein we review data and present new findings on aging-specific changes in motoneurons, skeletal muscle and the interplay between motoneurons and target muscle fibers. Although many of the changes occurring during aging may be specific to motoneurons and myofibers, respectively, evidence indicates that myofiber regeneration in sarcopenic muscle is halted at the point where reinnervation is critical for the final differentiation into mature myofibers. Combined, evidence suggests that sarcopenia to a significant extent depend on a decreased capacity among motoneurons to innervate regenerating fibers. There are also conspicuous changes in the expression of several cytokines known to play important roles in establishing and maintaining neuromuscular connectivity during development and adulthood. We also present data showing the usefulness of rodent models in studies of successful and unsuccessful patterns of aging. Finally, we show that not only dietary restriction (DR) but also activity and social environment may modulate the pattern of aging.
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Affiliation(s)
- Erik Edström
- Karolinska Institutet, Department of Neuroscience, Retzius Laboratory, S-171 77 Stockholm, Sweden
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44
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Blackbeard J, O'Dea KP, Wallace VCJ, Segerdahl A, Pheby T, Takata M, Field MJ, Rice ASC. Quantification of the rat spinal microglial response to peripheral nerve injury as revealed by immunohistochemical image analysis and flow cytometry. J Neurosci Methods 2007; 164:207-17. [PMID: 17553569 PMCID: PMC2726922 DOI: 10.1016/j.jneumeth.2007.04.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 04/17/2007] [Accepted: 04/22/2007] [Indexed: 12/29/2022]
Abstract
Microgliosis is implicated in the pathophysiology of several neurological disorders, including neuropathic pain. Consequently, perturbation of microgliosis is a mechanistic and drug development target in neuropathic pain, which highlights the requirement for specific, sensitive and reproducible methods of microgliosis measurement. In this study, we used the spinal microgliosis associated with L5 spinal nerve transection and minocycline-induced attenuation thereof to: (1) evaluate novel software based semi-quantitative image analysis paradigms for the assessment of immunohistochemical images. Microgliosis was revealed by immunoreactivity to OX42. Several image analysis paradigms were assessed and compared to a previously validated subjective categorical rating scale. This comparison revealed that grey scale measurement of the proportion of a defined area of spinal cord occupied by OX42 immunoreactive cells is a robust image analysis paradigm. (2) Develop and validate a flow cytometric approach for quantification of spinal microgliosis. The flow cytometric technique reliably quantified microgliosis in spinal cord cell suspensions, using OX42 and ED9 immunoreactivity to identify microglia. The results suggest that image analysis of immunohistochemical revelation of microgliosis reliably detects the spinal microgliosis in response to peripheral nerve injury and pharmacological attenuation thereof. In addition, flow cytometry provides an alternative approach for quantitative analysis of spinal microgliosis elicited by nerve injury.
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Affiliation(s)
- J Blackbeard
- Department of Anaesthetics, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital Campus, 369 Fulham Road, London SW10 9NH, UK.
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45
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Griffin R, Nally R, Nolan Y, McCartney Y, Linden J, Lynch MA. The age-related attenuation in long-term potentiation is associated with microglial activation. J Neurochem 2006; 99:1263-72. [PMID: 16981890 DOI: 10.1111/j.1471-4159.2006.04165.x] [Citation(s) in RCA: 213] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
It is well established that inflammatory changes contribute to brain ageing, and an increased concentration of proinflammatory cytokine, interleukin-1beta (IL-1beta), has been reported in the aged brain associated with a deficit in long-term potentiation (LTP) in rat hippocampus. The precise age at which changes are initiated is unclear. In this study, we investigate parallel changes in markers of inflammation and LTP in 3-, 9- and 15-month-old rats. We report evidence of increased hippocampal concentrations of the proinflammatory cytokines IL-1alpha, IL-18 and interferon-gamma (IFNgamma), which are accompanied by deficits in LTP in the older rats. We also show an increase in expression of markers of microglial activation, CD86, CD40 and intercellular adhesion molecules (ICAM). Associated with these changes, we observed a significant impairment of hippocampal LTP in the same rats. The importance of microglial activation in the attenuation of long-term potentiation (LTP) was demonstrated using an inhibitor of microglial activation, minocycline; partial restoration of LTP in 15-month-old rats was observed following administration of minocycline. We propose that signs of neuroinflammation are observed in middle age and that these changes, which are characterized by microglial activation, may be triggered by IL-18.
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Affiliation(s)
- Rebecca Griffin
- Trinity College Institute for Neuroscience and Physiology Department, Trinity College, Dublin, Ireland
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46
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Abstract
The aging brain is characterized by a demonstrable decrease in weight and volume, particularly after the age of 50. This atrophy, which affects both grey and white matter, is presumed to result from a loss of neurons and myelinated axons. Glial cells, on the other hand, appear to increase in the aging brain, which exhibits greater immunoreactivity with both astrocytic and microglial markers. This review is focused on the morphologic and phenotypic changes that occur in microglial cells with normal aging. Although there is a consistent aging-related upregulation of microglial activation markers in experimental animals and humans that could be interpreted as aging-related neuroinflammation, it is generally difficult to show a direct correlation between ostensible microglial activation and neurodegeneration. This raises questions about whether aging-related microglial activation indeed represents reactive gliosis in the conventional sense. As an alternative, we discuss the possibility that structural and phenotypic changes that occur in microglia are a direct reflection of the aging process on microglia. Thus, microglia cells themselves may be subject to cellular senescence in the sense that they no longer function efficiently. The concept of microglial senescence offers a novel perspective on aging-related neurodegeneration, namely that neurodegeneration could also occur secondary to microglial degeneration.
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Affiliation(s)
- Jessica R Conde
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, 32610, USA
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47
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Lynch AM, Loane DJ, Minogue AM, Clarke RM, Kilroy D, Nally RE, Roche OJ, O'Connell F, Lynch MA. Eicosapentaenoic acid confers neuroprotection in the amyloid-beta challenged aged hippocampus. Neurobiol Aging 2006; 28:845-55. [PMID: 16714069 DOI: 10.1016/j.neurobiolaging.2006.04.006] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 04/02/2006] [Accepted: 04/07/2006] [Indexed: 11/26/2022]
Abstract
Among the changes that occur in the hippocampus with age, is a deficit in long-term potentiation (LTP). This impairment is associated with inflammatory changes, which are typified by increased concentration of the pro-inflammatory cytokine interleukin-1beta (IL-1beta). Activated microglia are the most likely cell source of IL-1beta, but data demonstrating an age-related increase in microglial activation is equivocal. Here we demonstrate that the age-related deficit in LTP is accompanied by increased expression of cell surface markers of activated microglia (major histocompatibility complex II and CD40) and increased IL-1beta production, and that these changes may be stimulated by interferon-gamma. Treatment of aged rats with eicosapentaenoic acid (EPA) attenuates these changes and we suggest that IL-4 mediates the action of EPA. We demonstrate that aged rats exhibit an exaggerated response to intracerebroventricular injection of beta-amyloid peptide 1-40 (Abeta). Thus Abeta inhibited LTP in aged, but not young, rats and induced a further increase in hippocampal IL-1beta concentration. Of particular significance is the demonstration that EPA protects the aged brain so that the increased vulnerability to Abeta is ameliorated in EPA-treated rats.
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Affiliation(s)
- Aileen M Lynch
- Trinity College Institute of Neuroscience, Physiology Department, Trinity College, Dublin 2, Ireland
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48
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Maher FO, Clarke RM, Kelly A, Nally RE, Lynch MA. Interaction between interferon ? and insulin-like growth factor-1 in hippocampus impacts on the ability of rats to sustain long-term potentiation. J Neurochem 2006; 96:1560-71. [PMID: 16464236 DOI: 10.1111/j.1471-4159.2006.03664.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
There is compelling evidence to suggest that inflammation significantly contributes to neurodegenerative changes. Consistent with this is the observation that several neurodegenerative disorders are accompanied by an increase in the concentration of interleukin (IL)-1beta. IL-1beta has a negative impact on synaptic plasticity and therefore an increased concentration of IL-1beta, such as that in the hippocampus of the aged rat, is associated with a deficit in long-term potentiation (LTP). IL-1beta is derived mainly from activated microglia but the trigger leading to this activation, specifically in the aged brain, remains to be identified. Here we examined the possibility that interferon (IFN)gamma may stimulate microglial activation and increase IL-1beta concentration, thereby inhibiting LTP. The IFNgamma concentration was increased in hippocampus prepared from aged, compared with young, rats and inversely correlated with the ability of rats to sustain LTP. Intracerebroventricular injection of IFNgamma inhibited LTP, and increased microglial activation was observed in both IFNgamma-injected and aged rats. The age-related increase in IFNgamma was accompanied by a decrease in the hippocampal concentration of insulin-like growth factor (IGF)-1. The evidence presented suggests that IGF-1 acts to antagonize the IFNgamma-induced microglial activation, the accompanying increase in IL-1beta concentration and the consequent deficit in LTP.
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Affiliation(s)
- Frank O Maher
- Trinity College Institute for Neuroscience, Physiology Department, Trinity College, Dublin, Ireland
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49
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Cuadros MA, Santos AM, Martín-Oliva D, Calvente R, Tassi M, Marín-Teva JL, Navascués J. Specific immunolabeling of brain macrophages and microglial cells in the developing and mature chick central nervous system. J Histochem Cytochem 2006; 54:727-38. [PMID: 16461367 DOI: 10.1369/jhc.5a6832.2006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study showed that the HIS-C7 monoclonal antibody, which recognizes the chick form of CD45, is a specific marker for macrophages/microglial cells in the developing and mature chick central nervous system (CNS). HIS-C7-positive cells were characterized according to their morphological features and chronotopographical distribution patterns within developing and adult CNS, similar to those of macrophages/microglial cells in the quail CNS and confirmed by their histochemical labeling with Ricinus communis agglutinin I, a lectin that recognizes chick microglial cells. Therefore, the HIS-C7 antibody is a valuable tool to identify brain macrophage and microglial cells in studies of the function, development, and pathology of the chick brain. CD45 expression differed between chick microglia (as revealed with HIS-C7 antibody) and mouse microglial cells (as revealed with an antibody against mouse form of CD45). Thus, a discontinuous label was seen on mouse microglial cells with the anti-mouse CD45 immunostaining, whereas the entire surface of chick microglial cells was labeled with the anti-chick CD45 staining. The functional relevance of these differences between species has yet to be determined.
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Affiliation(s)
- Miguel A Cuadros
- Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain.
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50
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Conde JR, Streit WJ. Effect of aging on the microglial response to peripheral nerve injury. Neurobiol Aging 2005; 27:1451-61. [PMID: 16159684 DOI: 10.1016/j.neurobiolaging.2005.07.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Revised: 07/05/2005] [Accepted: 07/22/2005] [Indexed: 02/02/2023]
Abstract
Microglial morphology and immunophenotype have been studied extensively in aging-related neurodegenerative diseases, but to a lesser extent in the normally aged CNS, and little is known about how aging affects the ability of microglia to respond to neuronal injury. The goal of the current study was to determine if aging affects the ability of microglia to divide during the early response to facial nerve axotomy. In addition, we investigated the incidence of microglial cell death during later post-axotomy time points to determine if aging had an effect on microglial turnover. We employed DNA labeling with 3H-thymidine, TUNEL and lectin histochemistry after facial nerve axotomy in young (3 months), middle-aged (15 months), and old (30 months) Fisher344-Brown Norway hybrid rats. Proliferation of microglia in old rats remained significantly higher than in young rats 4 days after injury, suggesting that regulation of microglial proliferation changes with aging. There was no aging-related difference in microglial TUNEL staining at 7, 14 or 21 days post-axotomy. Lectin histochemistry in the unoperated facial nucleus revealed aging-related morphological changes in resting microglia, including hypertrophy of the cytoplasm with dense perinuclear staining. Aging-related differences in activated microglia on the lesioned side were more subtle, although many activated microglia of aged animals continued to exhibit dense perinuclear lectin reactivity. We propose that aging-related changes in morphology in conjunction with a less regulated proliferative response in the aged facial nucleus may be a reflection of microglial senescence.
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Affiliation(s)
- Jessica R Conde
- Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, P.O. Box 100244, Gainesville, FL 32610-0244, USA.
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