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Namjoshi DR, Cheng WH, McInnes KA, Martens KM, Carr M, Wilkinson A, Fan J, Robert J, Hayat A, Cripton PA, Wellington CL. Merging pathology with biomechanics using CHIMERA (Closed-Head Impact Model of Engineered Rotational Acceleration): a novel, surgery-free model of traumatic brain injury. Mol Neurodegener 2014; 9:55. [PMID: 25443413 PMCID: PMC4269957 DOI: 10.1186/1750-1326-9-55] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 11/20/2014] [Indexed: 12/14/2022] Open
Abstract
Background Traumatic brain injury (TBI) is a major health care concern that currently lacks any effective treatment. Despite promising outcomes from many preclinical studies, clinical evaluations have failed to identify effective pharmacological therapies, suggesting that the translational potential of preclinical models may require improvement. Rodents continue to be the most widely used species for preclinical TBI research. As most human TBIs result from impact to an intact skull, closed head injury (CHI) models are highly relevant, however, traditional CHI models suffer from extensive experimental variability that may be due to poor control over biomechanical inputs. Here we describe a novel CHI model called CHIMERA (Closed-Head Impact Model of Engineered Rotational Acceleration) that fully integrates biomechanical, behavioral, and neuropathological analyses. CHIMERA is distinct from existing neurotrauma model systems in that it uses a completely non-surgical procedure to precisely deliver impacts of prescribed dynamic characteristics to a closed skull while enabling kinematic analysis of unconstrained head movement. In this study, we characterized head kinematics as well as functional, neuropathological, and biochemical outcomes up to 14d following repeated TBI (rTBI) in adult C57BL/6 mice using CHIMERA. Results Head kinematic analysis showed excellent repeatability over two closed head impacts separated at 24h. Injured mice showed significantly prolonged loss of righting reflex and displayed neurological, motor, and cognitive deficits along with anxiety-like behavior. Repeated TBI led to diffuse axonal injury with extensive microgliosis in white matter from 2-14d post-rTBI. Injured mouse brains also showed significantly increased levels of TNF-α and IL-1β and increased endogenous tau phosphorylation. Conclusions Repeated TBI using CHIMERA mimics many of the functional and pathological characteristics of human TBI with a reliable biomechanical response of the head. This makes CHIMERA well suited to investigate the pathophysiology of TBI and for drug development programs. Electronic supplementary material The online version of this article (doi:10.1186/1750-1326-9-55) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Cheryl L Wellington
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, BC, Canada.
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Socodato R, Portugal CC, Domith I, Oliveira NA, Coreixas VSM, Loiola EC, Martins T, Santiago AR, Paes-de-Carvalho R, Ambrósio AF, Relvas JB. c-Src function is necessary and sufficient for triggering microglial cell activation. Glia 2014; 63:497-511. [PMID: 25421817 DOI: 10.1002/glia.22767] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 11/05/2014] [Indexed: 12/22/2022]
Abstract
Microglial cells are the resident macrophages of the central nervous system. Their function is essential for neuronal tissue homeostasis. After inflammatory stimuli, microglial cells become activated changing from a resting and highly ramified cell shape to an amoeboid-like morphology. These morphological changes are associated with the release of proinflammatory cytokines and glutamate, as well as with high phagocytic activity. The acquisition of such phenotype has been associated with activation of cytoplasmic tyrosine kinases, including those of the Src family (SFKs). In this study, using both in vivo and in vitro inflammation models coupled to FRET-based time-lapse microscopy, lentiviruses-mediated shRNA delivery and genetic gain-of-function experiments, we demonstrate that among SFKs c-Src function is necessary and sufficient for triggering microglia proinflammatory signature, glutamate release, microglia-induced neuronal loss, and phagocytosis. c-Src inhibition in retinal neuroinflammation experimental paradigms consisting of intravitreal injection of LPS or ischemia-reperfusion injury significantly reduced microglia activation changing their morphology to a more resting phenotype and prevented neuronal apoptosis. Our data demonstrate an essential role for c-Src in microglial cell activation.
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Affiliation(s)
- Renato Socodato
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal; Program of Neurosciences, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Department of Neurobiology, Institute of Biology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Faculty of Medicine, Centre of Ophthalmology and Vision Sciences, Institute for Biomedical Imaging and Life Sciences (IBILI), University of Coimbra, Coimbra, Portugal
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Torres-Platas SG, Cruceanu C, Chen GG, Turecki G, Mechawar N. Evidence for increased microglial priming and macrophage recruitment in the dorsal anterior cingulate white matter of depressed suicides. Brain Behav Immun 2014; 42:50-9. [PMID: 24858659 DOI: 10.1016/j.bbi.2014.05.007] [Citation(s) in RCA: 344] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 05/02/2014] [Accepted: 05/12/2014] [Indexed: 12/27/2022] Open
Abstract
Despite increasing evidence supporting the neuroinflammatory theory of depression, little is known about cerebral macrophages in individuals suffering from major depression. In the present study, we investigated the morphology and distribution of cells immunostained for the macrophage-specific marker ionized calcium binding adaptor molecule 1 (IBA1) in the dorsal anterior cingulate cortex (dACC) white matter of middle-aged depressed suicides and matched non-psychiatric controls. This region is known for its implication in mood disorders, and its white matter compartment was previously found to display hypertrophic astrocytes in depressed suicides. Distributions of IBA1-immunoreactive (IBA-IR) microglial phenotypes were assessed using stereology and cell morphometry, and blood vessels were characterized as being intimately associated with either a high or a low density of IBA1-IR amoeboid-like cells. Total densities of IBA1-IR microglia did not differ between depressed suicides and controls. However, a finer analysis examining relative proportions of microglial phenotypes revealed that the ratio of primed over ramified ("resting") microglia was significantly increased in depressed suicides. Strikingly, the proportion of blood vessels surrounded by a high density of macrophages was more than twice higher in depressed suicides than in controls, and this difference was strongly significant. Consistent with these observations, gene expression of IBA1 and MCP-1, a chemokine involved in the recruitment of circulating monocytes, was significantly upregulated in depressed suicides. Furthermore, mRNA for CD45, a marker enriched in perivascular macrophages, was also significantly increased in samples from depressed suicides. An increase compared to controls was also observed in the proportion of blood vessels surrounded by a high density of CD45-IR cells, but this difference did not reach significance. These histological and molecular data suggest the recruitment of monocytes in dACC white matter of depressed suicides, although it cannot be excluded that other types of macrophages (including microglia) account for the observed accumulation of macrophages closely associated with blood vessels. Altogether, these findings suggest that the previously reported depression- and suicide-associated increases in circulating pro-inflammatory cytokines may be associated with low-grade cerebral neuroinflammation involving the recruitment of circulating monocytes.
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Affiliation(s)
- Susana G Torres-Platas
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Québec H4H 1R3, Canada; McGill University, Integrated Program in Neuroscience, Québec, Canada
| | - Cristiana Cruceanu
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Québec H4H 1R3, Canada; McGill University, Dept. of Human Genetics, Québec, Canada
| | - Gary Gang Chen
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Québec H4H 1R3, Canada
| | - Gustavo Turecki
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Québec H4H 1R3, Canada; McGill University, Integrated Program in Neuroscience, Québec, Canada; McGill University, Dept. of Human Genetics, Québec, Canada; McGill University, Dept. of Psychiatry, Québec, Canada
| | - Naguib Mechawar
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, 6875 LaSalle Blvd, Verdun, Québec H4H 1R3, Canada; McGill University, Integrated Program in Neuroscience, Québec, Canada; McGill University, Dept. of Psychiatry, Québec, Canada.
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304
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Visuospatial learning and memory in the Cebus apella and microglial morphology in the molecular layer of the dentate gyrus and CA1 lacunosum molecular layer. J Chem Neuroanat 2014; 61-62:176-88. [PMID: 25462387 DOI: 10.1016/j.jchemneu.2014.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/18/2014] [Accepted: 10/13/2014] [Indexed: 11/23/2022]
Abstract
We investigated whether the morphology of microglia in the molecular layer of the dentate gyrus (DG-Mol) or in the lacunosum molecular layer of CA1 (CA1-LMol) was correlated with spatial learning and memory in the capuchin monkey (Cebus apella). Learning and memory was tested in 4 monkeys with visuo-spatial, paired associated learning (PAL) tasks from the Cambridge battery of neuropsychological tests. After testing, monkeys were sacrificed, and hippocampi were sectioned. We specifically immunolabeled microglia with an antibody against the adapter binding, ionized calcium protein. Microglia were selected from the middle and outer thirds of the DG-Mol (n=268) and the CA1-LMol (n=185) for three-dimensional reconstructions created with Neurolucida and Neuroexplorer software. Cluster and discriminant analyses, based on microglial morphometric parameters, identified two major morphological microglia phenotypes (types I and II) found in both the CA1-LMol and DG-Mol of all individuals. Compared to type II, type I microglia were significantly smaller, thinner, more tortuous and ramified, and less complex (lower fractal dimensions). PAL performance was both linearly and non-linearly correlated with type I microglial morphological features from the rostral and caudal DG-Mol, but not with microglia from the CA1-LMol. These differences in microglial morphology and correlations with PAL performance were consistent with previous proposals of hippocampal regional contributions for spatial learning and memory. Our results suggested that at least two morphological microglial phenotypes provided distinct physiological roles to learning-associated activity in the rostral and caudal DG-Mol of the monkey brain.
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305
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Xie C, Zhou K, Wang X, Blomgren K, Zhu C. Therapeutic benefits of delayed lithium administration in the neonatal rat after cerebral hypoxia-ischemia. PLoS One 2014; 9:e107192. [PMID: 25211332 PMCID: PMC4161387 DOI: 10.1371/journal.pone.0107192] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 08/07/2014] [Indexed: 01/02/2023] Open
Abstract
Aim We have previously shown that lithium treatment immediately after hypoxia-ischemia (HI) in neonatal rats affords both short- and long-term neuroprotection. The aim of this study was to evaluate possible therapeutic benefits when lithium treatment was delayed 5 days, a time point when most cell death is over. Methods Eight-day-old male rats were subjected to unilateral HI and 2 mmol/kg lithium chloride was injected intraperitoneally 5 days after the insult. Additional lithium injections of 1 mmol/kg were administered at 24 h intervals for the next 14 days. Brain injury was evaluated 12 weeks after HI. Serum cytokine measurements and behavioral analysis were performed before sacrificing the animals. Results Brain injury, as indicated by tissue loss, was reduced by 38.7%, from 276.5±27.4 mm3 in the vehicle-treated group to 169.3±25.9 mm3 in the lithium-treated group 12 weeks after HI (p<0.01). Motor hyperactivity and anxiety-like behavior after HI were normalized by lithium treatment. Lithium treatment increased neurogenesis in the dentate gyrus as indicated by doublecortin labeling. Serum cytokine levels, including IL-1α, IL-1β, and IL-6, were still elevated as late as 5 weeks after HI, but lithium treatment normalized these cytokine levels. Conclusions Delayed lithium treatment conferred long-term neuroprotection in neonatal rats after HI, and this opens a new avenue for future development of treatment strategies for neonatal brain injury that can be administered after the acute injury phase.
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Affiliation(s)
- Cuicui Xie
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, Göteborg, Sweden
- Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden
| | - Kai Zhou
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, Göteborg, Sweden
- Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden
| | - Xiaoyang Wang
- Perinatal Center, Institute of Neuroscience and Physiology, University of Gothenburg, Göteborg, Sweden
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Klas Blomgren
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, Göteborg, Sweden
- Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden
- Department of Pediatrics, University of Gothenburg, The Queen Silvia Children's Hospital, Gothenburg, Sweden
| | - Changlian Zhu
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, Göteborg, Sweden
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Pediatrics, Zhengzhou Children's Hospital, Zhengzhou, China
- * E-mail:
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306
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Sierra A, Tremblay MÈ, Wake H. Never-resting microglia: physiological roles in the healthy brain and pathological implications. Front Cell Neurosci 2014; 8:240. [PMID: 25177273 PMCID: PMC4133768 DOI: 10.3389/fncel.2014.00240] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 07/29/2014] [Indexed: 11/25/2022] Open
Affiliation(s)
- Amanda Sierra
- Ikerbasque Foundation, University of the Basque Country EHU/UPV Bilbao, Spain
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval Québec, Canada
| | - Hiroaki Wake
- Division of Brain Circuits, National Institute for Basic Biology, NINS Okazaki, Japan
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307
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Xi J, Si XA, Kim J, Mckee E, Lin EB. Exhaled aerosol pattern discloses lung structural abnormality: a sensitivity study using computational modeling and fractal analysis. PLoS One 2014; 9:e104682. [PMID: 25105680 PMCID: PMC4126729 DOI: 10.1371/journal.pone.0104682] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 07/16/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Exhaled aerosol patterns, also called aerosol fingerprints, provide clues to the health of the lung and can be used to detect disease-modified airway structures. The key is how to decode the exhaled aerosol fingerprints and retrieve the lung structural information for a non-invasive identification of respiratory diseases. OBJECTIVE AND METHODS In this study, a CFD-fractal analysis method was developed to quantify exhaled aerosol fingerprints and applied it to one benign and three malign conditions: a tracheal carina tumor, a bronchial tumor, and asthma. Respirations of tracer aerosols of 1 µm at a flow rate of 30 L/min were simulated, with exhaled distributions recorded at the mouth. Large eddy simulations and a Lagrangian tracking approach were used to simulate respiratory airflows and aerosol dynamics. Aerosol morphometric measures such as concentration disparity, spatial distributions, and fractal analysis were applied to distinguish various exhaled aerosol patterns. FINDINGS Utilizing physiology-based modeling, we demonstrated substantial differences in exhaled aerosol distributions among normal and pathological airways, which were suggestive of the disease location and extent. With fractal analysis, we also demonstrated that exhaled aerosol patterns exhibited fractal behavior in both the entire image and selected regions of interest. Each exhaled aerosol fingerprint exhibited distinct pattern parameters such as spatial probability, fractal dimension, lacunarity, and multifractal spectrum. Furthermore, a correlation of the diseased location and exhaled aerosol spatial distribution was established for asthma. CONCLUSION Aerosol-fingerprint-based breath tests disclose clues about the site and severity of lung diseases and appear to be sensitive enough to be a practical tool for diagnosis and prognosis of respiratory diseases with structural abnormalities.
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Affiliation(s)
- Jinxiang Xi
- School of Engineering and Technology, Central Michigan University, Mount Pleasant, Michigan, United States of America
| | - Xiuhua A. Si
- Science Division, Calvin College, Grand Rapids, Michigan, United States of America
| | - JongWon Kim
- School of Engineering and Technology, Central Michigan University, Mount Pleasant, Michigan, United States of America
| | - Edward Mckee
- College of Medicine, Central Michigan University, Mount Pleasant, Michigan, United States of America
| | - En-Bing Lin
- Department of Mathematics, Central Michigan University, Mount Pleasant, Michigan, United States of America
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308
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MANERA M, DEZFULI B, BORRECA C, GIARI L. The use of fractal dimension and lacunarity in the characterization of mast cell degranulation in rainbow trout (Onchorhynchus mykiss
). J Microsc 2014; 256:82-9. [DOI: 10.1111/jmi.12160] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 06/23/2014] [Indexed: 11/29/2022]
Affiliation(s)
- M. MANERA
- Faculty of Biosciences; Agro-Alimentary and Environmental Technologies; University of Teramo; Teramo Italy
| | - B.S. DEZFULI
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - C. BORRECA
- Small Animal Praxis; St. Metauro, I-64026 Roseto degli Abruzzi (TE) Italy
| | - L. GIARI
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
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309
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Neubrand VE, Pedreño M, Caro M, Forte-Lago I, Delgado M, Gonzalez-Rey E. Mesenchymal stem cells induce the ramification of microglia via the small RhoGTPases Cdc42 and Rac1. Glia 2014; 62:1932-42. [PMID: 24995657 DOI: 10.1002/glia.22714] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 05/26/2014] [Accepted: 06/18/2014] [Indexed: 12/11/2022]
Abstract
Activated microglia play a central role in the course of neurodegenerative diseases as they secrete cytotoxic substances which lead to neuronal cell death. Understanding the mechanisms that drive activation of microglia is essential to reverse this phenotype and to protect from neurodegeneration. With some exceptions, evidence indicates that changes in cell morphology from a star shape to a round and flat shape accompany the process of activation in microglia. In this study, we investigated the effect of adipose-tissue-derived mesenchymal stem cells (ASCs), which exert important anti-inflammatory actions, in microglia morphology. Microglia exposed to ASCs or their secreted factors (conditioned medium) underwent a cell shape change into a ramifying morphology in basal and inflammatory conditions, similar to that observed in microglia found in healthy brain. Colony-stimulating factor-1 secreted by ASCs played a critical role in the induction of this phenotype. Importantly, ASCs reversed the activated round phenotype induced in microglia by bacterial endotoxins. The ramifying morphology of microglia induced by ASCs was associated with a decrease of the proinflammatory cytokines tumor necrosis factor-α and interleukin-6, an increase in phagocytic activity, and the upregulation of neurotrophic factors and of Arginase-1, a marker for M2-like regulatory microglia. In addition, activation of the phosphoinositide-3-kinase/Akt pathway and the RhoGTPases Rac1 and Cdc42 played a major role in the acquisition of this phenotype. Therefore, these RhoGTPases emerge as key players in the ramification of microglia by anti-inflammatory agents like ASCs, being fundamental to maintain the tissue-surveying, central nervous system supporting state of microglia in healthy conditions.
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Affiliation(s)
- Veronika E Neubrand
- Institute of Parasitology and Biomedicine López-Neyra, Dept. Cell Biology and Immunology, IPBLN-CSIC, Avda. Conocimiento, PT Ciencias de La Salud, Granada, Spain
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310
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Huang EYK, Tsai TH, Kuo TT, Tsai JJ, Tsui PF, Chou YC, Ma HI, Chiang YH, Chen YH. Remote effects on the striatal dopamine system after fluid percussion injury. Behav Brain Res 2014; 267:156-72. [DOI: 10.1016/j.bbr.2014.03.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/14/2014] [Accepted: 03/18/2014] [Indexed: 01/25/2023]
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311
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Barreto GE, Santos-Galindo M, Garcia-Segura LM. Selective estrogen receptor modulators regulate reactive microglia after penetrating brain injury. Front Aging Neurosci 2014; 6:132. [PMID: 24999330 PMCID: PMC4064706 DOI: 10.3389/fnagi.2014.00132] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/05/2014] [Indexed: 11/13/2022] Open
Abstract
Following brain injury, microglia assume a reactive-like state and secrete pro-inflammatory molecules that can potentiate damage. A therapeutic strategy that may limit microgliosis is of potential interest. In this context, selective estrogen receptor modulators, such as raloxifene and tamoxifen, are known to reduce microglia activation induced by neuroinflammatory stimuli in young animals. In the present study, we have assessed whether raloxifene and tamoxifen are able to affect microglia activation after brain injury in young and aged animals in time points relevant to clinics, which is hours after brain trauma. Volume fraction of MHC-II(+) microglia was estimated according to the point-counting method of Weibel within a distance of 350 μm from the lateral border of the wound, and cellular morphology was measured by fractal analysis. Two groups of animals were studied: (1) young rats, ovariectomized at 2 months of age; and (2) aged rats, ovariectomized at 18 months of age. Fifteen days after ovariectomy animals received a stab wound brain injury and the treatment with estrogenic compounds. Our findings indicate that raloxifene and tamoxifen reduced microglia activation in both young and aged animals. Although the volume fraction of reactive microglia was found lower in aged animals, this was accompanied by important changes in cell morphology, where aged microglia assume a bushier and hyperplasic aspect when compared to young microglia. These data suggest that early regulation of microglia activation provides a mechanism by which selective estrogen receptors modulators (SERMs) may exert a neuroprotective effect in the setting of a brain trauma.
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Affiliation(s)
- George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana Bogotá, D.C., Colombia
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312
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Tishkina AO, Stepanichev MY, Lazareva NA, Kulagina AO, Gulyaeva NV. The glial response in the rodent hippocampus to systemic administration of bacterial lipopolysaccharide. NEUROCHEM J+ 2014. [DOI: 10.1134/s1819712414020111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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313
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Raj DDA, Jaarsma D, Holtman IR, Olah M, Ferreira FM, Schaafsma W, Brouwer N, Meijer MM, de Waard MC, van der Pluijm I, Brandt R, Kreft KL, Laman JD, de Haan G, Biber KPH, Hoeijmakers JHJ, Eggen BJL, Boddeke HWGM. Priming of microglia in a DNA-repair deficient model of accelerated aging. Neurobiol Aging 2014; 35:2147-60. [PMID: 24799273 DOI: 10.1016/j.neurobiolaging.2014.03.025] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 03/21/2014] [Accepted: 03/23/2014] [Indexed: 12/16/2022]
Abstract
Aging is associated with reduced function, degenerative changes, and increased neuroinflammation of the central nervous system (CNS). Increasing evidence suggests that changes in microglia cells contribute to the age-related deterioration of the CNS. The most prominent age-related change of microglia is enhanced sensitivity to inflammatory stimuli, referred to as priming. It is unclear if priming is due to intrinsic microglia ageing or induced by the ageing neural environment. We have studied this in Ercc1 mutant mice, a DNA repair-deficient mouse model that displays features of accelerated aging in multiple tissues including the CNS. In Ercc1 mutant mice, microglia showed hallmark features of priming such as an exaggerated response to peripheral lipopolysaccharide exposure in terms of cytokine expression and phagocytosis. Specific targeting of the Ercc1 deletion to forebrain neurons resulted in a progressive priming response in microglia exemplified by phenotypic alterations. Summarizing, these data show that neuronal genotoxic stress is sufficient to switch microglia from a resting to a primed state.
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Affiliation(s)
- Divya D A Raj
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Dick Jaarsma
- Department of Neuroscience, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Inge R Holtman
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Marta Olah
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Filipa M Ferreira
- Department of Neuroscience, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Wandert Schaafsma
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Nieske Brouwer
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Michel M Meijer
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Monique C de Waard
- Department of Genetics, Cancer Genomics Center, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Ingrid van der Pluijm
- Department of Genetics, Cancer Genomics Center, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Renata Brandt
- Department of Genetics, Cancer Genomics Center, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Karim L Kreft
- Department of Immunology, Erasmus University Medical Center and MS Center ErasMS, Rotterdam, the Netherlands; Department of Neurology, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Jon D Laman
- Department of Immunology, Erasmus University Medical Center and MS Center ErasMS, Rotterdam, the Netherlands
| | - Gerald de Haan
- Department of Cell Biology, European Research Institute on the Biology of Aging, University of Groningen, University Medical Center, Groningen, the Netherlands
| | - Knut P H Biber
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Psychiatry and Psychotherapy, University Medical Center, Freiburg, Germany
| | - Jan H J Hoeijmakers
- Department of Genetics, Cancer Genomics Center, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Bart J L Eggen
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Hendrikus W G M Boddeke
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
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314
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Torres-Platas SG, Comeau S, Rachalski A, Bo GD, Cruceanu C, Turecki G, Giros B, Mechawar N. Morphometric characterization of microglial phenotypes in human cerebral cortex. J Neuroinflammation 2014; 11:12. [PMID: 24447857 PMCID: PMC3906907 DOI: 10.1186/1742-2094-11-12] [Citation(s) in RCA: 223] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 01/10/2014] [Indexed: 11/16/2022] Open
Abstract
Background Microglia can adopt different morphologies, ranging from a highly ramified to an amoeboid-like phenotype. Although morphological properties of microglia have been described in rodents, little is known about their fine features in humans. The aim of this study was to characterize the morphometric properties of human microglia in gray and white matter of dorsal anterior cingulate cortex (dACC), a region implicated in behavioral adaptation to neuroinflammation. These properties were compared to those of murine microglia in order to gain a better appreciation of the differences displayed by these cells across species. Methods Postmortem dACC samples were analyzed from 11 individuals having died suddenly without any history of neuroinflammatory, neurodegenerative, nor psychiatric illness. Tissues were sectioned and immunostained for the macrophage marker Ionized calcium binding adaptor molecule 1 (IBA1). Randomly selected IBA1-immunoreactive (IBA1-IR) cells displaying features corresponding to commonly accepted microglial phenotypes (ramified, primed, reactive, amoeboid) were reconstructed in 3D and all aspects of their morphologies quantified using the Neurolucida software. The relative abundance of each morphological phenotype was also assessed. Furthermore, adult mouse brains were similarly immunostained, and IBA1-IR cells in cingulate cortex were compared to those scrutinized in human dACC. Results In human cortical gray and white matter, all microglial phenotypes were observed in significant proportions. Compared to ramified, primed microglia presented an average 2.5 fold increase in cell body size, with almost no differences in branching patterns. When compared to the primed microglia, which projected an average of six primary processes, the reactive and amoeboid phenotypes displayed fewer processes and branching points, or no processes at all. In contrast, the majority of microglial cells in adult mouse cortex were highly ramified. This was also the case following a postmortem interval of 43 hours. Interestingly, the morphology of ramified microglia was strikingly similar between species. Conclusions This study provides fundamental information on the morphological features of microglia in the normal adult human cerebral cortex. These morphometric data will be useful for future studies of microglial morphology in various illnesses. Furthermore, this first direct comparison of human and mouse microglia reveals that these brain cells are morphologically similar across species, suggesting highly conserved functions.
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Affiliation(s)
| | | | | | | | | | | | | | - Naguib Mechawar
- McGill Group for Suicide Studies, 6875 LaSalle Blvd, Verdun, Québec H4H 1R3, Canada.
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315
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Ren X, Guo X, Chen L, Guo M, Peng N, Li R. Attenuated migration by green tea extract (−)-epigallocatechin gallate (EGCG): involvement of 67 kDa laminin receptor internalization in macrophagic cells. Food Funct 2014; 5:1915-9. [PMID: 24953562 DOI: 10.1039/c4fo00143e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Inhibition of macrophagic cell migration induced by green tea polyphenol EGCG may be linked to the internalization of 67 kDa laminin receptor.
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Affiliation(s)
- Xuezhi Ren
- Department of Neurology
- Shaanxi Provincial People's Hospital
- Xi'an 710068, China
- The Third Affiliated Hospital
- Xi'an Jiaotong University School of Medicine
| | - Xingzhi Guo
- Department of Neurology
- Shaanxi Provincial People's Hospital
- Xi'an 710068, China
- The Third Affiliated Hospital
- Xi'an Jiaotong University School of Medicine
| | - Li Chen
- Department of Neurology
- Shaanxi Provincial People's Hospital
- Xi'an 710068, China
| | - Minxia Guo
- Department of Neurology
- Shaanxi Provincial People's Hospital
- Xi'an 710068, China
| | - Ning Peng
- Department of Neurology
- Shaanxi Provincial People's Hospital
- Xi'an 710068, China
| | - Rui Li
- Department of Neurology
- Shaanxi Provincial People's Hospital
- Xi'an 710068, China
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316
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Lima CB, Soares GDSF, Vitor SM, Andrade-da-Costa BLDS, Castellano B, Guedes RCA. Spreading depression features and Iba1 immunoreactivity in the cerebral cortex of developing rats submitted to treadmill exercise after treatment with monosodium glutamate. Int J Dev Neurosci 2013; 33:98-105. [PMID: 24374255 DOI: 10.1016/j.ijdevneu.2013.12.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 11/09/2013] [Accepted: 12/18/2013] [Indexed: 12/18/2022] Open
Abstract
Physical exercise and excessive consumption of monosodium glutamate (MSG) can affect the morphological and electrophysiological organization of the brain during development. However, the interaction of both factors remains unclear. We analyzed the effect of this interaction on the excitability-related phenomenon known as cortical spreading depression (CSD) and the microglial reaction expressed as Iba1-immunolabeled cells in the rat motor cortex. MSG (2g/kg or 4g/kg) was administered every other day during the first 14 postnatal days. Treadmill exercise started at 21-23 days of life and lasted 3 weeks, 5 days/week, for 30min/day. At 45-60 days, CSD was recorded for 4h at two cortical points and the CSD parameters (velocity, amplitude, and duration of the negative potential change) calculated. Confirming previous observations, exercised rats presented with lower CSD velocities (3.29±0.18mm/min) than the sedentary group (3.80±0.18mm/min; P<0.05). MSG increased CSD velocities in the exercised rats compared to saline-treated and exercised animals in a dose-dependent manner (3.49±0.19, 4.05±0.18, and 3.27±0.26 for 2g/kg MSG, 4g/kg MSG, and saline, respectively; P<0.05). The amplitude (ranging from 14.3±5.9 to 18.7±6.2mV) and duration (46.7±11.1 to 60.5±11.6s) of the negative slow potential shift of the CSD were similar in all groups. Both exercise and MSG treatment increased Iba1 immunolabeling. The results confirm that physical exercise decelerates CSD propagation. However, it does not impede the CSD-accelerating action of MSG. These effects were accompanied by a cortical microglia reaction. Therefore, the data suggest that treadmill exercise early in life can influence the development of cortical electrical activity.
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Affiliation(s)
- Cássia Borges Lima
- Department of Physiology and Pharmacology, Universidade Federal de Pernambuco, 50670901 Recife, Brazil
| | | | - Suênia Marcele Vitor
- Department of Nutrition, Universidade Federal de Pernambuco, 50670901 Recife, Brazil
| | | | - Bernardo Castellano
- Unit of Medical Histology, Institute of Neuroscience and Dept Cell Biology, Physiology and Immunology, Autonomous University of Barcelona, Spain
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317
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von Leden RE, Cooney SJ, Ferrara TM, Zhao Y, Dalgard CL, Anders JJ, Byrnes KR. 808 nm wavelength light induces a dose-dependent alteration in microglial polarization and resultant microglial induced neurite growth. Lasers Surg Med 2013; 45:253-63. [PMID: 23619903 DOI: 10.1002/lsm.22133] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2013] [Indexed: 01/20/2023]
Abstract
BACKGROUND AND OBJECTIVE Despite the success of using photobiomodulation (PBM), also known as low level light therapy, in promoting recovery after central nervous system (CNS) injury, the effect of PBM on microglia, the primary mediators of immune and inflammatory response in the CNS, remains unclear. Microglia exhibit a spectrum of responses to injury, with partial or full polarization into pro- and anti-inflammatory phenotypes. Pro-inflammatory (M1 or classically activated) microglia contribute to chronic inflammation and neuronal toxicity, while anti-inflammatory (M2 or alternatively activated) microglia play a role in wound healing and tissue repair; microglia can fall anywhere along this spectrum in response to stimulation. MATERIALS AND METHODS The effect of PBM on microglial polarization therefore was investigated using colorimetric assays, immunocytochemistry, proteomic profiling and RT-PCR in vitro after exposure of primary microglia or BV2 microglial cell line to PBM of differing energy densities (0.2, 4, 10, and 30 J/cm(2) , 808 nm wavelength, 50 mW output power). RESULTS PBM has a dose-dependent effect on the spectrum of microglial M1 and M2 polarization. Specifically, PBM with energy densities between 4 and 30 J/cm(2) induced expression of M1 markers in microglia. Markers of the M2 phenotype, including CD206 and TIMP1, were observed at lower energy densities of 0.2-10 J/cm(2) . In addition, co-culture of PBM or control-treated microglia with primary neuronal cultures demonstrated a dose-dependent effect of PBM on microglial-induced neuronal growth and neurite extension. CONCLUSION These data suggest that the Arndt-Schulz law as applied to PBM for a specific bioassay does not hold true in cells with a spectrum of responses, and that PBM can alter microglial phenotype across this spectrum in a dose-dependent manner. These data are therefore of important relevance to not only therapies in the CNS but also to understanding of PBM effects and mechanisms.
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Affiliation(s)
- Ramona E von Leden
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Jones Bridge Road, Bethesda, Maryland 20814, USA
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318
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Abstract
Fractal characteristics of chromatin, revealed by light or electron microscopy, have been reported during the last 20 years. Fractal features can easily be estimated in digitalized microscopic images and are helpful for diagnosis and prognosis of neoplasias. During carcinogenesis and tumor progression, an increase of the fractal dimension (FD) of stained nuclei has been shown in intraepithelial lesions of the uterine cervix and the anus, oral squamous cell carcinomas or adenocarcinomas of the pancreas. Furthermore, an increased FD of chromatin is an unfavorable prognostic factor in squamous cell carcinomas of the oral cavity and the larynx, melanomas and multiple myelomas. High goodness-of-fit of the regression line of the FD is a favorable prognostic factor in acute leukemias and multiple myelomas. The nucleus has fractal and power-law organization in several different levels, which might in part be interrelated. Some possible relations between modifications of the chromatin organization during carcinogenesis and tumor progression and an increase of the FD of stained chromatin are suggested. Furthermore, increased complexity of the chromatin structure, loss of heterochromatin and a less-perfect self-organization of the nucleus in aggressive neoplasias are discussed.
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Affiliation(s)
- Konradin Metze
- Department of Pathology, Faculty of Medical Sciences Research Group, 'Analytical Cellular Pathology' and National Institute of Photonics Applied to Cell Biology, University of Campinas, Campinas, Brazil +55 19 32893897 kmetze.at.fcm.unicamp.br
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