101
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Xie F, Zhang F, Min S, Chen J, Yang J, Wang X. Glial cell line-derived neurotrophic factor (GDNF) attenuates the peripheral neuromuscular dysfunction without inhibiting the activation of spinal microglia/monocyte. BMC Geriatr 2018; 18:110. [PMID: 29743034 PMCID: PMC5944173 DOI: 10.1186/s12877-018-0796-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Accepted: 04/30/2018] [Indexed: 12/13/2022] Open
Abstract
Background Peripheral neuromuscular dysfunctions were found in elderly individuals, and spinal microglia/monocyte plays an important role on this process. This study aims to test whether the glial cell line-derived neurotrophic factor (GDNF) could attenuate age-related neuromuscular dysfunction by inhibiting the activation of spinal microglia/monocyte. Methods Male Sprague-Dawley rats were divided into an adult group and an aged group. The aged rats were intrathecally injected with normal saline (NS) and GDNF. All the rats were harvested 5 days after each injection. The muscular function was tested by compound muscle action potential, and the activation of microglia/monocyte was detected by immunofluorescence staining; cytokines were assayed by enzyme-linked immunosorbent assay; the expression level of GDNF and its known receptor GFR-α in the spinal cord, the expression level of neuregulin-1 (NRG-1) in the sciatic nerve, and the expression level of γ- and α7- ε-nicotinic acetylcholine receptors in the tibialis anterior muscle were measured by western blotting. Results The activated microglia/monocyte was found in the aged rats compared to the adult rats. The aged rats showed a significant neuromuscular dysfunction and cytokine release as well as increased expression of γ- and α7-nAChR. The protein expression of GDNF, GFR-α, and NRG-1 in the aged rats were significantly lower than that in the adult rats. However, the exogenous injection of GDNF could alleviate the neuromuscular dysfunction but not inhibit the activation of spinal microglia/monocyte. Furthermore, the levels of GFR-α and NRG-1 also increased after GDNF treatment. Conclusion The GDNF could attenuate the age-related peripheral neuromuscular dysfunction without inhibiting the activation of microglia/monocyte in the spinal cord.
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Affiliation(s)
- Fei Xie
- Department of Anesthesiology, the First Affiliated Hospital of Chongqing Medical University, Friendship Road 1#, Yuan Jia Gang, Chongqing, 400016, China
| | - Fan Zhang
- Department of Anesthesiology, the People's Hospital of Jianyang City, Chengdu, Sichuan, China
| | - Su Min
- Department of Anesthesiology, the First Affiliated Hospital of Chongqing Medical University, Friendship Road 1#, Yuan Jia Gang, Chongqing, 400016, China.
| | - Jingyuan Chen
- Department of Anesthesiology, the First Affiliated Hospital of Chongqing Medical University, Friendship Road 1#, Yuan Jia Gang, Chongqing, 400016, China
| | - Jun Yang
- Department of Anesthesiology, the First Affiliated Hospital of Chongqing Medical University, Friendship Road 1#, Yuan Jia Gang, Chongqing, 400016, China
| | - Xin Wang
- Department of Anesthesiology, the First Affiliated Hospital of Chongqing Medical University, Friendship Road 1#, Yuan Jia Gang, Chongqing, 400016, China
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102
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Kokiko-Cochran ON, Godbout JP. The Inflammatory Continuum of Traumatic Brain Injury and Alzheimer's Disease. Front Immunol 2018; 9:672. [PMID: 29686672 PMCID: PMC5900037 DOI: 10.3389/fimmu.2018.00672] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/19/2018] [Indexed: 12/23/2022] Open
Abstract
The post-injury inflammatory response is a key mediator in long-term recovery from traumatic brain injury (TBI). Moreover, the immune response to TBI, mediated by microglia and macrophages, is influenced by existing brain pathology and by secondary immune challenges. For example, recent evidence shows that the presence of beta-amyloid and phosphorylated tau protein, two hallmark features of AD that increase during normal aging, substantially alter the macrophage response to TBI. Additional data demonstrate that post-injury microglia are “primed” and become hyper-reactive following a subsequent acute immune challenge thereby worsening recovery. These alterations may increase the incidence of neuropsychiatric complications after TBI and may also increase the frequency of neurodegenerative pathology. Therefore, the purpose of this review is to summarize experimental studies examining the relationship between TBI and development of AD-like pathology with an emphasis on the acute and chronic microglial and macrophage response following injury. Furthermore, studies will be highlighted that examine the degree to which beta-amyloid and tau accumulation as well as pre- and post-injury immune stressors influence outcome after TBI. Collectively, the studies described in this review suggest that the brain’s immune response to injury is a key mediator in recovery, and if compromised by previous, coincident, or subsequent immune stressors, post-injury pathology and behavioral recovery will be altered.
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Affiliation(s)
- Olga N Kokiko-Cochran
- Department of Neuroscience, Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Jonathan P Godbout
- Department of Neuroscience, Institute for Behavioral Medicine Research, The Ohio State University Wexner Medical Center, Columbus, OH, United States
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103
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El Massri N, Weinrich TW, Kam JH, Jeffery G, Mitrofanis J. Photobiomodulation reduces gliosis in the basal ganglia of aged mice. Neurobiol Aging 2018; 66:131-137. [PMID: 29571001 PMCID: PMC5933512 DOI: 10.1016/j.neurobiolaging.2018.02.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/05/2018] [Accepted: 02/15/2018] [Indexed: 11/15/2022]
Abstract
This study explored the effects of long-term photobiomodulation (PBM) on the glial and neuronal organization in the striatum of aged mice. Mice aged 12 months were pretreated with PBM (670 nm) for 20 minutes per day, commencing at 5 months old and continued for 8 months. We had 2 control groups, young at 3 months and aged at 12 months old; these mice received no treatment. Brains were aldehyde-fixed and processed for immunohistochemistry with various glial and neuronal markers. We found a clear reduction in glial cell number, both astrocytes and microglia, in the striatum after PBM in aged mice. By contrast, the number of 2 types of striatal interneurons (parvalbumin+ and encephalopsin+), together with the density of striatal dopaminergic terminals (and their midbrain cell bodies), remained unchanged after such treatment. In summary, our results indicated that long-term PBM had beneficial effects on the aging striatum by reducing glial cell number; and furthermore, that this treatment did not have any deleterious effects on the neurons and terminations in this nucleus.
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Affiliation(s)
- Nabil El Massri
- Department of Anatomy F13, University of Sydney, Sydney, NSW, Australia
| | - Tobias W Weinrich
- Institute of Ophthalmology, University College London, London, England
| | - Jaimie Hoh Kam
- Institute of Ophthalmology, University College London, London, England
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, London, England
| | - John Mitrofanis
- Department of Anatomy F13, University of Sydney, Sydney, NSW, Australia.
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104
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Taipa R, Sousa AL, Melo Pires M, Sousa N. Does the Interplay Between Aging and Neuroinflammation Modulate Alzheimer's Disease Clinical Phenotypes? A Clinico-Pathological Perspective. J Alzheimers Dis 2018; 53:403-17. [PMID: 27176075 DOI: 10.3233/jad-160121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder and is the most common cause of dementia worldwide. Cumulative data suggests that neuroinflammation plays a prominent and early role in AD, and there is compelling data from different research groups of age-associated dysregulation of the neuroimmune system. From the clinical point of view, despite clinical resemblance and neuropathological findings, there are important differences between the group of patients with sporadic early-onset (<65 years old) and late-onset AD (>65 years old). Thus, it seems important to understand the age-dependent relationship between neuroinflammation and the underlying biology of AD in order to identify potential explanations for clinical heterogeneity, interpret biomarkers, and promote the best treatment to different clinical AD phenotypes. The study of the delicate balance between pro-inflammatory or anti-inflammatory sides of immune players in the different ages of onset of AD would be important to understand treatment efficacy in clinical trials and eventually, not only direct treatment to early disease stages, but also the possibility of establishing different treatment approaches depending on the age of the patient. In this review, we would like to summarize what is currently known about the interplay between "normal" age associated inflammatory changes and AD pathological mechanisms, and also the potential differences between early-onset and late-onset AD taking into account the age-related neuroimmune background at disease onset.
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Affiliation(s)
- Ricardo Taipa
- Neuropathology Unit, Department of Neuroscience, Hospital Santo António - Centro Hospitalar do Porto, Porto, Portugal.,Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.,ICVS/3B's Associate Lab, PT Government Associated Lab, Braga/Guimarães, Portugal
| | - Ana Luísa Sousa
- Department of Neurology, Hospital Santo António - Centro Hospitalar do Porto, Porto, Portugal
| | - Manuel Melo Pires
- Neuropathology Unit, Department of Neuroscience, Hospital Santo António - Centro Hospitalar do Porto, Porto, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.,ICVS/3B's Associate Lab, PT Government Associated Lab, Braga/Guimarães, Portugal
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105
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Yanguas-Casás N, Crespo-Castrillo A, de Ceballos ML, Chowen JA, Azcoitia I, Arevalo MA, Garcia-Segura LM. Sex differences in the phagocytic and migratory activity of microglia and their impairment by palmitic acid. Glia 2017; 66:522-537. [PMID: 29139169 DOI: 10.1002/glia.23263] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/25/2017] [Accepted: 10/30/2017] [Indexed: 12/11/2022]
Abstract
Sex differences in the incidence, clinical manifestation, disease course, and prognosis of neurological diseases, such as autism spectrum disorders or Alzheimer's disease, have been reported. Obesity has been postulated as a risk factor for cognitive decline and Alzheimer's disease and, during pregnancy, increases the risk of autism spectrum disorders in the offspring. Obesity is associated with increased serum and brain levels of free fatty acids, such as palmitic acid, which activate microglial cells triggering a potent inflammatory cascade. In this study, we have determined the effect of palmitic acid in the inflammatory profile, motility, and phagocytosis of primary male and female microglia, both in basal conditions and in the presence of a pro-inflammatory stimulus (interferon-γ). Male microglia in vitro showed higher migration than female microglia under basal and stimulated conditions. In contrast, female microglia had higher basal and stimulated phagocytic activity than male microglia. Palmitic acid did not affect basal migration or phagocytosis, but abolished the migration and phagocytic activity of male and female microglia in response to interferon-γ. These findings extend previous observations of sex differences in microglia and suggest that palmitic acid impairs the protective responses of these cells.
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Affiliation(s)
| | | | | | - Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, 28009, Spain.,CIBER de Investigación Biomédica en Red: Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Iñigo Azcoitia
- Department of Cell Biology, Faculty of Biology, Universidad Complutense, Madrid, 28040, Spain.,CIBER de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Maria Angeles Arevalo
- Instituto Cajal, CSIC, Madrid, 28002, Spain.,CIBER de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Luis M Garcia-Segura
- Instituto Cajal, CSIC, Madrid, 28002, Spain.,CIBER de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
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106
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Singhal G, Baune BT. Microglia: An Interface between the Loss of Neuroplasticity and Depression. Front Cell Neurosci 2017; 11:270. [PMID: 28943841 PMCID: PMC5596091 DOI: 10.3389/fncel.2017.00270] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/21/2017] [Indexed: 12/11/2022] Open
Abstract
Depression has been widely accepted as a major psychiatric disease affecting nearly 350 million people worldwide. Research focus is now shifting from studying the extrinsic and social factors of depression to the underlying molecular causes. Microglial activity is shown to be associated with pathological conditions, such as psychological stress, pathological aging, and chronic infections. These are primary immune effector cells in the CNS and regulate the extensive dialogue between the nervous and the immune systems in response to different immunological, physiological, and psychological stressors. Studies have suggested that during stress and pathologies, microglia play a significant role in the disruption of neuroplasticity and have detrimental effects on neuroprotection causing neuroinflammation and exacerbation of depression. After a systematic search of literature databases, relevant articles on the microglial regulation of bidirectional neuroimmune pathways affecting neuroplasticity and leading to depression were reviewed. Although, several hypotheses have been proposed for the microglial role in the onset of depression, it is clear that all molecular pathways to depression are linked through microglia-associated neuroinflammation and hippocampal degeneration. Molecular factors such as an excess of glucocorticoids and changes in gene expression of neurotrophic factors, as well as neuro active substances secreted by gut microbiota have also been shown to affect microglial morphology and phenotype resulting in depression. This review aims to critically analyze the various molecular pathways associated with the microglial role in depression.
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Affiliation(s)
| | - Bernhard T. Baune
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, University of AdelaideAdelaide, SA, Australia
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107
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Zrzavy T, Hametner S, Wimmer I, Butovsky O, Weiner HL, Lassmann H. Loss of 'homeostatic' microglia and patterns of their activation in active multiple sclerosis. Brain 2017; 140:1900-1913. [PMID: 28541408 PMCID: PMC6057548 DOI: 10.1093/brain/awx113] [Citation(s) in RCA: 411] [Impact Index Per Article: 58.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/19/2017] [Indexed: 02/07/2023] Open
Abstract
Microglia and macrophages accumulate at the sites of active demyelination and neurodegeneration in the multiple sclerosis brain and are thought to play a central role in the disease process. We used recently described markers to characterize the origin and functional states of microglia/macrophages in acute, relapsing and progressive multiple sclerosis. We found microglia activation in normal white matter of controls and that the degree of activation increased with age. This microglia activation was more pronounced in the normal-appearing white matter of patients in comparison to controls and increased with disease duration. In contrast to controls, the normal-appearing white matter of patients with multiple sclerosis showed a significant reduction of P2RY12, a marker expressed in homeostatic microglia in rodents, which was completely lost in active and slowly expanding lesions. Early stages of demyelination and neurodegeneration in active lesions contained microglia with a pro-inflammatory phenotype, which expressed molecules involved in phagocytosis, oxidative injury, antigen presentation and T cell co-stimulation. In later stages, the microglia and macrophages in active lesions changed to a phenotype that was intermediate between pro- and anti-inflammatory activation. In inactive lesions, the density of microglia/macrophages was significantly reduced and microglia in part converted to a P2RY12+ phenotype. Analysis of TMEM119, which is expressed on microglia but not on recruited macrophages, demonstrated that on average 45% of the macrophage-like cells in active lesions were derived from the resident microglia pool. Our study demonstrates the loss of the homeostatic microglial signature in active multiple sclerosis with restoration associated with disease inactivity.
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Affiliation(s)
- Tobias Zrzavy
- Center for Brain Research, Medical University of Vienna, Austria
| | - Simon Hametner
- Center for Brain Research, Medical University of Vienna, Austria
| | - Isabella Wimmer
- Center for Brain Research, Medical University of Vienna, Austria
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women´s Hospital, Harvard Medical School, Boston, MA, USA
| | - Howard L Weiner
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women´s Hospital, Harvard Medical School, Boston, MA, USA
| | - Hans Lassmann
- Center for Brain Research, Medical University of Vienna, Austria
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108
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Zucca FA, Segura-Aguilar J, Ferrari E, Muñoz P, Paris I, Sulzer D, Sarna T, Casella L, Zecca L. Interactions of iron, dopamine and neuromelanin pathways in brain aging and Parkinson's disease. Prog Neurobiol 2017; 155:96-119. [PMID: 26455458 PMCID: PMC4826627 DOI: 10.1016/j.pneurobio.2015.09.012] [Citation(s) in RCA: 423] [Impact Index Per Article: 60.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 09/14/2015] [Accepted: 09/17/2015] [Indexed: 12/11/2022]
Abstract
There are several interrelated mechanisms involving iron, dopamine, and neuromelanin in neurons. Neuromelanin accumulates during aging and is the catecholamine-derived pigment of the dopamine neurons of the substantia nigra and norepinephrine neurons of the locus coeruleus, the two neuronal populations most targeted in Parkinson's disease. Many cellular redox reactions rely on iron, however an altered distribution of reactive iron is cytotoxic. In fact, increased levels of iron in the brain of Parkinson's disease patients are present. Dopamine accumulation can induce neuronal death; however, excess dopamine can be removed by converting it into a stable compound like neuromelanin, and this process rescues the cell. Interestingly, the main iron compound in dopamine and norepinephrine neurons is the neuromelanin-iron complex, since neuromelanin is an effective metal chelator. Neuromelanin serves to trap iron and provide neuronal protection from oxidative stress. This equilibrium between iron, dopamine, and neuromelanin is crucial for cell homeostasis and in some cellular circumstances can be disrupted. Indeed, when neuromelanin-containing organelles accumulate high load of toxins and iron during aging a neurodegenerative process can be triggered. In addition, neuromelanin released by degenerating neurons activates microglia and the latter cause neurons death with further release of neuromelanin, then starting a self-propelling mechanism of neuroinflammation and neurodegeneration. Considering the above issues, age-related accumulation of neuromelanin in dopamine neurons shows an interesting link between aging and neurodegeneration.
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Affiliation(s)
- Fabio A Zucca
- Institute of Biomedical Technologies, National Research Council of Italy, Segrate, Milan, Italy
| | - Juan Segura-Aguilar
- Faculty of Medicine, Molecular and Clinical Pharmacology, ICBM, University of Chile, Santiago, Chile
| | - Emanuele Ferrari
- Institute of Biomedical Technologies, National Research Council of Italy, Segrate, Milan, Italy
| | - Patricia Muñoz
- Faculty of Medicine, Molecular and Clinical Pharmacology, ICBM, University of Chile, Santiago, Chile
| | - Irmgard Paris
- Faculty of Medicine, Molecular and Clinical Pharmacology, ICBM, University of Chile, Santiago, Chile; Department of Basic Sciences, Faculty of Sciences, Santo Tomás University, Viña del Mar, Chile
| | - David Sulzer
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA; Department of Neurology, Columbia University Medical Center, New York, NY, USA; Department of Pharmacology, Columbia University Medical Center, New York, NY, USA
| | - Tadeusz Sarna
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Luigi Casella
- Department of Chemistry, University of Pavia, Pavia, Italy
| | - Luigi Zecca
- Institute of Biomedical Technologies, National Research Council of Italy, Segrate, Milan, Italy.
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109
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Horowitz AM, Villeda SA. Therapeutic potential of systemic brain rejuvenation strategies for neurodegenerative disease. F1000Res 2017; 6:1291. [PMID: 28815019 PMCID: PMC5539850 DOI: 10.12688/f1000research.11437.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/26/2017] [Indexed: 12/18/2022] Open
Abstract
Neurodegenerative diseases are a devastating group of conditions that cause progressive loss of neuronal integrity, affecting cognitive and motor functioning in an ever-increasing number of older individuals. Attempts to slow neurodegenerative disease advancement have met with little success in the clinic; however, a new therapeutic approach may stem from classic interventions, such as caloric restriction, exercise, and parabiosis. For decades, researchers have reported that these systemic-level manipulations can promote major functional changes that extend organismal lifespan and healthspan. Only recently, however, have the functional effects of these interventions on the brain begun to be appreciated at a molecular and cellular level. The potential to counteract the effects of aging in the brain, in effect rejuvenating the aged brain, could offer broad therapeutic potential to combat dementia-related neurodegenerative disease in the elderly. In particular, results from heterochronic parabiosis and young plasma administration studies indicate that pro-aging and rejuvenating factors exist in the circulation that can independently promote or reverse age-related phenotypes. The recent demonstration that human umbilical cord blood similarly functions to rejuvenate the aged brain further advances this work to clinical translation. In this review, we focus on these blood-based rejuvenation strategies and their capacity to delay age-related molecular and functional decline in the aging brain. We discuss new findings that extend the beneficial effects of young blood to neurodegenerative disease models. Lastly, we explore the translational potential of blood-based interventions, highlighting current clinical trials aimed at addressing therapeutic applications for the treatment of dementia-related neurodegenerative disease in humans.
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Affiliation(s)
- Alana M. Horowitz
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, California, 94143, USA
- Department of Anatomy, University of California San Francisco, San Francisco, California, 94143, USA
| | - Saul A. Villeda
- Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, California, 94143, USA
- Department of Anatomy, University of California San Francisco, San Francisco, California, 94143, USA
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, California, 94143, USA
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110
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Mangold CA, Wronowski B, Du M, Masser DR, Hadad N, Bixler GV, Brucklacher RM, Ford MM, Sonntag WE, Freeman WM. Sexually divergent induction of microglial-associated neuroinflammation with hippocampal aging. J Neuroinflammation 2017; 14:141. [PMID: 28732515 PMCID: PMC5521082 DOI: 10.1186/s12974-017-0920-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 07/13/2017] [Indexed: 01/11/2023] Open
Abstract
Background The necessity of including both males and females in molecular neuroscience research is now well understood. However, there is relatively limited basic biological data on brain sex differences across the lifespan despite the differences in age-related neurological dysfunction and disease between males and females. Methods Whole genome gene expression of young (3 months), adult (12 months), and old (24 months) male and female C57BL6 mice hippocampus was analyzed. Subsequent bioinformatic analyses and confirmations of age-related changes and sex differences in hippocampal gene and protein expression were performed. Results Males and females demonstrate both common expression changes with aging and marked sex differences in the nature and magnitude of the aging responses. Age-related hippocampal induction of neuroinflammatory gene expression was sexually divergent and enriched for microglia-specific genes such as complement pathway components. Sexually divergent C1q protein expression was confirmed by immunoblotting and immunohistochemistry. Similar patterns of cortical sexually divergent gene expression were also evident. Additionally, inter-animal gene expression variability increased with aging in males, but not females. Conclusions These findings demonstrate sexually divergent neuroinflammation with aging that may contribute to sex differences in age-related neurological diseases such as stroke and Alzheimer’s, specifically in the complement system. The increased expression variability in males suggests a loss of fidelity in gene expression regulation with aging. These findings reveal a central role of sex in the transcriptomic response of the hippocampus to aging that warrants further, in depth, investigations. Electronic supplementary material The online version of this article (doi:10.1186/s12974-017-0920-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Colleen A Mangold
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, State College, PA, USA
| | - Benjamin Wronowski
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Mei Du
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Dustin R Masser
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Reynolds Oklahoma Center on Aging & Nathan Shock Center of Excellence in the Biology of Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Niran Hadad
- Reynolds Oklahoma Center on Aging & Nathan Shock Center of Excellence in the Biology of Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Georgina V Bixler
- Genome Sciences Facility, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Robert M Brucklacher
- Genome Sciences Facility, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Matthew M Ford
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, Oregon, USA
| | - William E Sonntag
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Reynolds Oklahoma Center on Aging & Nathan Shock Center of Excellence in the Biology of Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Willard M Freeman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. .,Reynolds Oklahoma Center on Aging & Nathan Shock Center of Excellence in the Biology of Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. .,Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, USA. .,, SLY-BRC 1370, 975 NE 10th St, Oklahoma City, OK, 73104, USA.
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111
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Arcuri C, Mecca C, Bianchi R, Giambanco I, Donato R. The Pathophysiological Role of Microglia in Dynamic Surveillance, Phagocytosis and Structural Remodeling of the Developing CNS. Front Mol Neurosci 2017; 10:191. [PMID: 28674485 PMCID: PMC5474494 DOI: 10.3389/fnmol.2017.00191] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/30/2017] [Indexed: 12/13/2022] Open
Abstract
In vertebrates, during an early wave of hematopoiesis in the yolk sac between embryonic day E7.0 and E9.0, cells of mesodermal leaflet addressed to macrophage lineage enter in developing central nervous system (CNS) and originate the developing native microglial cells. Depending on the species, microglial cells represent 5–20% of glial cells resident in adult brain. Here, we briefly discuss some canonical functions of the microglia, i.e., cytokine secretion and functional transition from M1 to M2 phenotype. In addition, we review studies on the non-canonical functions of microglia such as regulation of phagocytosis, synaptic pruning, and sculpting postnatal neural circuits. In this latter context the contribution of microglia to some neurodevelopmental disorders is now well established. Nasu-Hakola (NHD) disease is considered a primary microgliopathy with alterations of the DNAX activation protein 12 (DAP12)-Triggering receptor expressed on myeloid cells 2 (TREM-2) signaling and removal of macromolecules and apoptotic cells followed by secondary microglia activation. In Rett syndrome Mecp2-/- microglia shows a substantial impairment of phagocytic ability, although the role of microglia is not yet clear. In a mouse model of Tourette syndrome (TS), microglia abnormalities have also been described, and deficient microglia-mediated neuroprotection is obvious. Here we review the role of microglial cells in neurodevelopmental disorders without inflammation and on the complex role of microglia in developing CNS.
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Affiliation(s)
- Cataldo Arcuri
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Carmen Mecca
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Roberta Bianchi
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Ileana Giambanco
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Rosario Donato
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
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余 军, 赵 维, 杜 春, 张 娜, 张 卫, 晋 圣, 汪 海, 冯 泽. [Choline improves lipopolysaccharide-induced central nervous system inflammatory response and cognitive dysfunction in mice]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2017; 37:600-606. [PMID: 28539281 PMCID: PMC6780474 DOI: 10.3969/j.issn.1673-4254.2017.05.06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To assess the effect of choline in ameliorating lipopolysaccharide (LPS)-induced central nervous system inflammation and cognitive deficits in mice and explore the underlying mechanism. METHODS Seventy-two mice were randomized into saline control group, LPS group, choline intervention group and choline control group. In the latter two groups, the mice received pretreatment with intraperitoneal injections of choline (40 mg/kg, 3 times daily for 3 consecutive days) prior to microinjection of LPS into the lateral cerebral ventricle to induce central nervous system inflammation; in saline and LPS groups, the mice were pretreated with saline in the same manner before intraventicular injection of artificial cerebrospinal fluid. Choline treatment was administered in the mice till the end of the experiment. The locomotor activity and spatial learning and memory capacity of the mice were examined. The expressions of Iba1 protein and proinflammatory cytokines (TNF-α and IL-β) I the hippocampal dentate gyrus, and the expressions of α 7nAchR, p38 MAPK and phosphorylated p38 MAPK in the hippocampus of the mice were detected. RESULTS Water maze test showed that compared with the saline control group, the mice in LPS group exhibited significantly reduced platform crossings (P<0.05), which was significantly increased by choline pretreatment (P<0.05). The mice pretreated with LPS expressed obviously increased levels of IBA-1 protein, TNF-α, and IL-1β in the hippocampus (P<0.01), and choline pretreatment significantly lowered the expressions of IBA-1 protein and IL-1β (P<0.05). The phosphorylation level of p38 MAPK increased significantly after LPS pretreatment (P<0.05), and was reduced by choline pretreatment (P<0.05); α 7nAchR expression increased significantly in choline intervention group as compared with that in the other 3 groups (P<0.05). CONCLUSION Choline can probably antagonize LPS-induced hippocampal p38 MAPK phosphorylation in mice via the α 7nAchR signaling pathway to protective against LPS-induced neuroinflammation and cognitive impairment in mice.
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Affiliation(s)
- 军 余
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 维星 赵
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 春彦 杜
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 娜 张
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 卫东 张
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 圣阳 晋
- 中国医学科学院北京协和医学院,北京 100730Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - 海 汪
- 军事医学科学院卫生学环境医学研究所心血管药物研究中心,北京 100850Cardiovascular Drug Research Center, Institute of Hea1th and Environmental Medicine, Academy of Military Medical Sciences, Beijing 100850, China
| | - 泽国 冯
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
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113
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Park E, Chun HS. Protective Effects of Curcumin on Manganese-Induced BV-2 Microglial Cell Death. Biol Pharm Bull 2017; 40:1275-1281. [PMID: 28529240 DOI: 10.1248/bpb.b17-00160] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Curcumin, a bioactive component in tumeric, has been shown to exert antioxidant, anti-inflammatory, anticarcinogenic, hepatoprotective, and neuroprotective effects, but the effects of curcumin against manganese (Mn)-mediated neurotoxicity have not been studied. This study examined the protective effects of curcumin on Mn-induced cytotoxicity in BV-2 microglial cells. Curcumin (0.1-10 µM) dose-dependently prevented Mn (250 µM)-induced cell death. Mn-induced mitochondria-related apoptotic characteristics, such as caspase-3 and -9 activation, cytochrome c release, Bax increase, and Bcl-2 decrease, were significantly suppressed by curcumin. In addition, curcumin significantly increased intracellular glutathione (GSH) and moderately potentiated superoxide dismutase (SOD), both which were diminished by Mn treatment. Curcumin pretreatment effectively suppressed Mn-induced upregulation of malondialdehyde (MDA), total reactive oxygen species (ROS). Moreover, curcumin markedly inhibited the Mn-induced mitochondrial membrane potential (MMP) loss. Furthermore, curcumin was able to induce heme oxygenase (HO)-1 expression. Curcumin-mediated inhibition of ROS, down-regulation of caspases, restoration of MMP, and recovery of cell viability were partially reversed by HO-1 inhibitor (SnPP). These results suggest the first evidence that curcumin can prevent Mn-induced microglial cell death through the induction of HO-1 and regulation of oxidative stress, mitochondrial dysfunction, and apoptotic events.
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Affiliation(s)
- Euteum Park
- Department of Biomedical Science, Chosun University
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114
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Intermittent fasting combined with supplementation with Ayurvedic herbs reduces anxiety in middle aged female rats by anti-inflammatory pathways. Biogerontology 2017; 18:601-614. [DOI: 10.1007/s10522-017-9706-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 04/28/2017] [Indexed: 12/25/2022]
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115
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Flowers A, Bell-Temin H, Jalloh A, Stevens SM, Bickford PC. Proteomic anaysis of aged microglia: shifts in transcription, bioenergetics, and nutrient response. J Neuroinflammation 2017; 14:96. [PMID: 28468668 PMCID: PMC5415769 DOI: 10.1186/s12974-017-0840-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/14/2017] [Indexed: 01/01/2023] Open
Abstract
Background Age is the primary risk factor for many diseases. As such, age is a critical co-factor for examination in order to understand the progression and potential intervention in disease progression. Studies examining both the phenotype and transcriptome of aged microglia demonstrated a propensity for the development of a pro-inflammatory phenotype. Less well studied is the concomitant blunting of anti-inflammatory aspects of microglial function with age which also impact plasticity and repair in the CNS. Methods This study utilizes mass spectrometry-based proteomics to compare primary microglia from young and aged animals. Results This study revealed alterations in three clusters of inter-related proteins. The three pathways were inflammatory signaling, mitochondrial function, and cellular metabolism. Analysis of these clusters identified the protein rapamycin-insensitive companion of mTOR (RICTOR), a component of the mTORC2 complex, as a novel upstream regulator of several biological functions that are altered with age and potentially linked to phenotype development. A decrease in mTORC2-dependent AKT S473 phosphorylation, as assessed by insulin growth factor (IGF) treatment, was observed in aged microglia. This novel finding was confirmed by genetic manipulation of the microglial cell line. BV2 cells with diminished RICTOR displayed a phenotype that was strikingly similar to that of aged microglia. This finding is particularly relevant as the mTOR pathway already has a number of pharmacological modulators used clinically. Conclusions The results suggest that microglia from aged mice show changes in cellular metabolism and energy regulation that might underlie the alterations in inflammatory signaling. Modulation of one pathway identified in our bioinformatic analysis, RICTOR, may provide an avenue by which deleterious aspects of the aging microglia can be attenuated. If successful, this could mean potentially delaying or diminishing the progress of diseases for which progressive inflammation is involved. Electronic supplementary material The online version of this article (doi:10.1186/s12974-017-0840-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Antwoine Flowers
- Department of Neurosurgery and Brain Repair, USF Health Morsani College of Medicine, University of South Florida, 12901 Bruce B Downs Blvd., Campus Box MDC-78, Tampa, FL, 33570, USA.,Department of Molecular Pharmacology and Physiology, USF Health Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Harris Bell-Temin
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL, USA
| | - Ahmad Jalloh
- Department of Neurosurgery and Brain Repair, USF Health Morsani College of Medicine, University of South Florida, 12901 Bruce B Downs Blvd., Campus Box MDC-78, Tampa, FL, 33570, USA.,Department of Molecular Pharmacology and Physiology, USF Health Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Stanley M Stevens
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL, USA
| | - Paula C Bickford
- Department of Neurosurgery and Brain Repair, USF Health Morsani College of Medicine, University of South Florida, 12901 Bruce B Downs Blvd., Campus Box MDC-78, Tampa, FL, 33570, USA. .,Department of Molecular Pharmacology and Physiology, USF Health Morsani College of Medicine, University of South Florida, Tampa, FL, USA. .,Research Service, James A Haley VA Hospital, Tampa, FL, USA.
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116
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Shobin E, Bowley MP, Estrada LI, Heyworth NC, Orczykowski ME, Eldridge SA, Calderazzo SM, Mortazavi F, Moore TL, Rosene DL. Microglia activation and phagocytosis: relationship with aging and cognitive impairment in the rhesus monkey. GeroScience 2017; 39:199-220. [PMID: 28238188 PMCID: PMC5411373 DOI: 10.1007/s11357-017-9965-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 02/07/2017] [Indexed: 02/07/2023] Open
Abstract
While cognitive decline is observed in the normal aging monkey, neurons are not lost with age. Instead, frontal white matter is lost as myelin degenerates and both correlate with age-related cognitive decline. As age-related myelin damage increases, there should be an increase in clearance of damaged myelin by microglial phagocytosis. In this study, brains of behaviorally tested rhesus monkeys were assessed using unbiased stereology to quantify the density of activated microglia (LN3 antibody positive) and phagocytic microglia (galectin-3 (Gal-3) antibody positive) in three white matter regions: the corpus callosum, cingulum bundle (CGB), and frontal white matter (FWM). LN3 cell density was significantly increased in the CGB, whereas Gal-3 cell density was significantly increased in all regions. Increases in Gal-3 cell density in the FWM were associated with cognitive impairment. In the FWM of old animals, Gal-3-positive microglia were classified by morphological subtype as ramified, hypertrophic, or amoeboid. The densities of hypertrophic and amoeboid microglia significantly correlated with cognitive impairment. Finally, microglia were double-labeled with LN3 and Gal-3 showing that 91% of Gal-3 cells were also LN3 positive, thus expressing an "activated" phenotype. Furthermore, 15% of all double-labeled cells formed phagocytic cups. Overall, these results suggest that microglia become activated in white matter with age where the majority express a phagocytic phenotype. We hypothesize that age-related phagocytic activation of microglia is a response to accumulating myelin pathology. The association of Gal-3 in the FWM with cognitive impairment may reflect regional differences in damage or dysfunction of normal clearance mechanisms.
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Affiliation(s)
- Eli Shobin
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA.
- Graduate Program for Neuroscience, Boston University, Boston, MA, 02118, USA.
| | - Michael P Bowley
- Department of Neurology, Massachusetts General Hospital, Boston, MA, 02144, USA
| | - Larissa I Estrada
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
- Department of Pharmacology and Experimental Therapeutics, Boston University, Boston, MA, 02118, USA
| | - Nadine C Heyworth
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
| | - Mary E Orczykowski
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
| | - Sherri A Eldridge
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
- Biology Department, University of Massachusetts Dartmouth, Dartmouth, MA, 02747, USA
| | | | - Farzad Mortazavi
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
| | - Tara L Moore
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
- Department of Neurology, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Douglas L Rosene
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, 02118, USA
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117
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Michels M, Sonai B, Dal-Pizzol F. Polarization of microglia and its role in bacterial sepsis. J Neuroimmunol 2017; 303:90-98. [PMID: 28087076 DOI: 10.1016/j.jneuroim.2016.12.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/04/2016] [Accepted: 12/28/2016] [Indexed: 12/14/2022]
Abstract
Microglial polarization in response to brain inflammatory conditions is a crescent field in neuroscience. However, the effect of systemic inflammation, and specifically sepsis, is a relatively unexplored field that has great interest and relevance. Sepsis has been associated with both early and late harmful events of the central nervous system, suggesting that there is a close link between sepsis and neuroinflammation. During sepsis evolution it is supposed that microglial could exert both neurotoxic and repairing effects depending on the specific microglial phenotype assumed. In this context, here it was reviewed the role of microglial polarization during sepsis-associated brain dysfunction.
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Affiliation(s)
- Monique Michels
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil.
| | - Beatriz Sonai
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil.
| | - Felipe Dal-Pizzol
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av Universitária, 1105, Criciúma 88806000, SC, Brazil; Center of Excellence in Applied Neurosciences of Santa Catarina (NENASC), Graduate Program in Medical Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil.
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118
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Martin E, Boucher C, Fontaine B, Delarasse C. Distinct inflammatory phenotypes of microglia and monocyte-derived macrophages in Alzheimer's disease models: effects of aging and amyloid pathology. Aging Cell 2017; 16:27-38. [PMID: 27723233 PMCID: PMC5242297 DOI: 10.1111/acel.12522] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2016] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by formation of amyloid‐β (Aβ) plaques, activated microglia, and neuronal cell death leading to progressive dementia. Recent data indicate that microglia and monocyte‐derived macrophages (MDM) are key players in the initiation and progression of AD, yet their respective roles remain to be clarified. As AD occurs mostly in the elderly and aging impairs myeloid functions, we addressed the inflammatory profile of microglia and MDM during aging in TgAPP/PS1 and TgAPP/PS1dE9, two transgenic AD mouse models, compared to WT littermates. We only found MDM infiltration in very aged mice. We determined that MDM highly expressed activation markers at basal state. In contrast, microglia exhibited an activated phenotype only with normal aging and Aβ pathology. Our study showed that CD14 and CD36, two receptors involved in phagocytosis, were upregulated during Aβ pathogenesis. Moreover, we observed, at the protein levels in AD models, higher production of pro‐inflammatory mediators: IL‐1β, p40, iNOS, CCL‐3, CCL‐4, and CXCL‐1. Taken together, our data indicate that microglia and MDM display distinct phenotypes in AD models and highlight the specific effects of normal aging vs Aβ peptides on inflammatory processes that occur during the disease progression. These precise phenotypes of different subpopulations of myeloid cells in normal and pathologic conditions may allow the design of pertinent therapeutic strategy for AD.
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Affiliation(s)
- Elodie Martin
- Inserm U 1127; CNRS UMR 7225; Sorbonne Universités; UPMC Univ Paris 06 UMR S 1127; Institut du Cerveau et de la Moelle épinière (ICM); F-75013 Paris France
| | - Céline Boucher
- Inserm U 1127; CNRS UMR 7225; Sorbonne Universités; UPMC Univ Paris 06 UMR S 1127; Institut du Cerveau et de la Moelle épinière (ICM); F-75013 Paris France
| | - Bertrand Fontaine
- Inserm U 1127; CNRS UMR 7225; Sorbonne Universités; UPMC Univ Paris 06 UMR S 1127; Institut du Cerveau et de la Moelle épinière (ICM); F-75013 Paris France
- AP-HP; Hôpital de la Pitié Salpêtrière; F-75013 Paris France
| | - Cécile Delarasse
- Inserm U 1127; CNRS UMR 7225; Sorbonne Universités; UPMC Univ Paris 06 UMR S 1127; Institut du Cerveau et de la Moelle épinière (ICM); F-75013 Paris France
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119
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Barzilai A, Schumacher B, Shiloh Y. Genome instability: Linking ageing and brain degeneration. Mech Ageing Dev 2017; 161:4-18. [DOI: 10.1016/j.mad.2016.03.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/23/2016] [Accepted: 03/26/2016] [Indexed: 02/06/2023]
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120
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Coisne C, Tilloy S, Monflier E, Wils D, Fenart L, Gosselet F. Cyclodextrins as Emerging Therapeutic Tools in the Treatment of Cholesterol-Associated Vascular and Neurodegenerative Diseases. Molecules 2016; 21:E1748. [PMID: 27999408 PMCID: PMC6273856 DOI: 10.3390/molecules21121748] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 12/13/2016] [Accepted: 12/14/2016] [Indexed: 12/20/2022] Open
Abstract
Cardiovascular diseases, like atherosclerosis, and neurodegenerative diseases affecting the central nervous system (CNS) are closely linked to alterations of cholesterol metabolism. Therefore, innovative pharmacological approaches aiming at counteracting cholesterol imbalance display promising therapeutic potential. However, these approaches need to take into account the existence of biological barriers such as intestinal and blood-brain barriers which participate in the organ homeostasis and are major defense systems against xenobiotics. Interest in cyclodextrins (CDs) as medicinal agents has increased continuously based on their ability to actively extract lipids from cell membranes and to provide suitable carrier system for drug delivery. Many novel CD derivatives are constantly generated with the objective to improve CD bioavailability, biocompatibility and therapeutic outcomes. Newly designed drug formulation complexes incorporating CDs as drug carriers have demonstrated better efficiency in treating cardiovascular and neurodegenerative diseases. CD-based therapies as cholesterol-sequestrating agent have recently demonstrated promising advances with KLEPTOSE® CRYSMEB in atherosclerosis as well as with the 2-hydroxypropyl-β-cyclodextrin (HPβCD) in clinical trials for Niemann-Pick type C disease. Based on this success, many investigations evaluating the therapeutical beneficial of CDs in Alzheimer's, Parkinson's and Huntington's diseases are currently on-going.
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Affiliation(s)
- Caroline Coisne
- Laboratoire de la barrière hémato-encéphalique (LBHE), University Artois, EA 2465, Lens, F-62300, France.
| | - Sébastien Tilloy
- Unité de Catalyse et de Chimie du Solide (UCCS), University Artois, CNRS, UMR 8181, Lens, F-62300, France.
| | - Eric Monflier
- Unité de Catalyse et de Chimie du Solide (UCCS), University Artois, CNRS, UMR 8181, Lens, F-62300, France.
| | - Daniel Wils
- ROQUETTE, Nutrition & Health R & D, 62136 Lestrem, France.
| | - Laurence Fenart
- Laboratoire de la barrière hémato-encéphalique (LBHE), University Artois, EA 2465, Lens, F-62300, France.
| | - Fabien Gosselet
- Laboratoire de la barrière hémato-encéphalique (LBHE), University Artois, EA 2465, Lens, F-62300, France.
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121
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Carreira LM. Using Bronson Equation to Accurately Predict the Dog Brain Weight Based on Body Weight Parameter. Vet Sci 2016; 3:vetsci3040036. [PMID: 29056744 PMCID: PMC5606585 DOI: 10.3390/vetsci3040036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 11/20/2016] [Accepted: 11/29/2016] [Indexed: 12/03/2022] Open
Abstract
The study used 69 brains (n = 69) from adult dog cadavers, divided by their skull type into three groups, brachi (B), dolicho (D) and mesaticephalic (M) (n = 23 each), and aimed: (1) to determine whether the Bronson equation may be applied, without reservation, to estimate brain weight (BW) in brachy (B), dolicho (D), and mesaticephalic (M) dog breeds; and (2) to evaluate which breeds are more closely related to each other in an evolutionary scenario. All subjects were identified by sex, age, breed, and body weight (bw). An oscillating saw was used for a circumferential craniotomy to open the skulls; the brains were removed and weighed using a digital scale. For statistical analysis, p-values < 0.05 were considered significant. The work demonstrated a strong relationship between the observed and predicted BW by using the Bronson equation. It was possible to hypothesize that groups B and D present a greater encephalization level than M breeds, that B and D dog breeds are more closely related to each other than to M, and from the three groups, the D individuals presented the highest brain mass mean.
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Affiliation(s)
- L Miguel Carreira
- Faculty of Veterinary Medicine, University of Lisbon (FMV/ULisboa), Av. da Universidade Técnica de Lisboa, Polo Universitário Alto da Ajuda, Lisbon 1300-477, Portugal.
- Centre for Interdisciplinary Research in Animal Health (CIISA), FMV/ULisboa, Av. da Universidade Técnica de Lisboa, Polo Universitário Alto da Ajuda, Lisbon 1300-477, Portugal.
- Anjos of Assis Veterinary Medicine Centre (CMVAA), Rua Dª. Francisca da Azambuja Nº 9-9A, Barreiro 2830-077, Portugal.
- Private Practice in Human Dentistry, Oral Medicine and Surgery Clinic, Lisbon 1300-477, Portugal.
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Weissleder C, Fung SJ, Wong MW, Barry G, Double KL, Halliday GM, Webster MJ, Weickert CS. Decline in Proliferation and Immature Neuron Markers in the Human Subependymal Zone during Aging: Relationship to EGF- and FGF-Related Transcripts. Front Aging Neurosci 2016; 8:274. [PMID: 27932973 PMCID: PMC5123444 DOI: 10.3389/fnagi.2016.00274] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/03/2016] [Indexed: 12/13/2022] Open
Abstract
Neuroblasts exist within the human subependymal zone (SEZ); however, it is debated to what extent neurogenesis changes during normal aging. It is also unknown how precursor proliferation may correlate with the generation of neuronal and glial cells or how expression of growth factors and receptors may change throughout the adult lifespan. We found evidence of dividing cells in the human SEZ (n D 50) in conjunction with a dramatic age-related decline (21-103 years) of mRNAs indicative of proliferating cells (Ki67) and immature neurons (doublecortin). Microglia mRNA (ionized calcium-binding adapter molecule 1) increased during aging, whereas transcript levels of stem/precursor cells (glial fibrillary acidic protein delta and achaete-scute homolog 1), astrocytes (vimentin and pan-glial fibrillary acidic protein), and oligodendrocytes (oligodendrocyte lineage transcription factor 2) remained stable. Epidermal growth factor receptor (EGFR) and fibroblast growth factor 2 (FGF2) mRNAs increased throughout adulthood, while transforming growth factor alpha (TGFα), EGF, Erb-B2 receptor tyrosine kinase 4 (ErbB4) and FGF receptor 1 (FGFR1) mRNAs were unchanged across adulthood. Cell proliferation mRNA positively correlated with FGFR1 transcripts. Immature neuron and oligodendrocyte marker expression positively correlated with TGFα and ErbB4 mRNAs, whilst astrocyte transcripts positively correlated with EGF, FGF2, and FGFR1 mRNAs. Microglia mRNA positively correlated with EGF and FGF2 expression. Our findings indicate that neurogenesis in the human SEZ continues well into adulthood, although proliferation and neuronal differentiation may decline across adulthood. We suggest that mRNA expression of EGF- and FGF-related family members do not become limited during aging and may modulate neuronal and glial fate determination in the SEZ throughout human life.
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Affiliation(s)
- Christin Weissleder
- Schizophrenia Research Laboratory, Neuroscience Research AustraliaSydney, NSW, Australia; Schizophrenia Research InstituteSydney, NSW, Australia; School of Psychiatry, Faculty of Medicine, University of New South WalesSydney, NSW, Australia
| | - Samantha J Fung
- Schizophrenia Research Laboratory, Neuroscience Research AustraliaSydney, NSW, Australia; Schizophrenia Research InstituteSydney, NSW, Australia; School of Psychiatry, Faculty of Medicine, University of New South WalesSydney, NSW, Australia
| | - Matthew W Wong
- Schizophrenia Research Laboratory, Neuroscience Research AustraliaSydney, NSW, Australia; Schizophrenia Research InstituteSydney, NSW, Australia; School of Psychiatry, Faculty of Medicine, University of New South WalesSydney, NSW, Australia; School of Medical Sciences, Faculty of Medicine, University of New South WalesSydney, NSW, Australia
| | - Guy Barry
- Garvan Institute of Medical Research, St. Vincent's Clinical School and School of Biotechnology and Biomolecular Sciences, University of New South Wales Sydney, NSW, Australia
| | - Kay L Double
- Brain and Mind Research Institute, School of Medical Sciences, Sydney Medical School, University of Sydney Sydney, NSW, Australia
| | - Glenda M Halliday
- School of Medical Sciences, Faculty of Medicine, University of New South WalesSydney, NSW, Australia; Neuroscience Research AustraliaSydney, NSW, Australia
| | - Maree J Webster
- Laboratory of Brain Research, The Stanley Medical Research Institute Kensington, MD, USA
| | - Cynthia Shannon Weickert
- Schizophrenia Research Laboratory, Neuroscience Research AustraliaSydney, NSW, Australia; Schizophrenia Research InstituteSydney, NSW, Australia; School of Psychiatry, Faculty of Medicine, University of New South WalesSydney, NSW, Australia
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Walker T, Michaelides C, Ekonomou A, Geraki K, Parkes HG, Suessmilch M, Herlihy AH, Crum WR, So PW. Dissociation between iron accumulation and ferritin upregulation in the aged substantia nigra: attenuation by dietary restriction. Aging (Albany NY) 2016; 8:2488-2508. [PMID: 27743512 PMCID: PMC5115902 DOI: 10.18632/aging.101069] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/26/2016] [Indexed: 01/13/2023]
Abstract
Despite regulation, brain iron increases with aging and may enhance aging processes including neuroinflammation. Increases in magnetic resonance imaging transverse relaxation rates, R2 and R2*, in the brain have been observed during aging. We show R2 and R2* correlate well with iron content via direct correlation to semi-quantitative synchrotron-based X-ray fluorescence iron mapping, with age-associated R2 and R2* increases reflecting iron accumulation. Iron accumulation was concomitant with increased ferritin immunoreactivity in basal ganglia regions except in the substantia nigra (SN). The unexpected dissociation of iron accumulation from ferritin-upregulation in the SN suggests iron dyshomeostasis in the SN. Occurring alongside microgliosis and astrogliosis, iron dyshomeotasis may contribute to the particular vulnerability of the SN. Dietary restriction (DR) has long been touted to ameliorate brain aging and we show DR attenuated age-related in vivo R2 increases in the SN over ages 7 - 19 months, concomitant with normal iron-induction of ferritin expression and decreased microgliosis. Iron is known to induce microgliosis and conversely, microgliosis can induce iron accumulation, which of these may be the initial pathological aging event warrants further investigation. We suggest iron chelation therapies and anti-inflammatory treatments may be putative 'anti-brain aging' therapies and combining these strategies may be synergistic.
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Affiliation(s)
- Thomas Walker
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Christos Michaelides
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Antigoni Ekonomou
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Kalotina Geraki
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Harold G Parkes
- CR-UK Clinical MR Research Group, Institute of Cancer Research, London, United Kingdom
| | - Maria Suessmilch
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | | | - William R Crum
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Po-Wah So
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
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124
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Mecha M, Carrillo-Salinas F, Feliú A, Mestre L, Guaza C. Microglia activation states and cannabinoid system: Therapeutic implications. Pharmacol Ther 2016; 166:40-55. [DOI: 10.1016/j.pharmthera.2016.06.011] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2016] [Indexed: 12/16/2022]
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125
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Buijs M, Doan NT, van Rooden S, Versluis MJ, van Lew B, Milles J, van der Grond J, van Buchem MA. In vivo assessment of iron content of the cerebral cortex in healthy aging using 7-Tesla T2*-weighted phase imaging. Neurobiol Aging 2016; 53:20-26. [PMID: 28199888 DOI: 10.1016/j.neurobiolaging.2016.09.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/06/2016] [Accepted: 09/08/2016] [Indexed: 01/18/2023]
Abstract
Accumulation of brain iron has been suggested as a biomarker of neurodegeneration. Increased iron has been seen in the cerebral cortex in postmortem studies of neurodegenerative diseases and healthy aging. Until recently, the diminutive thickness of the cortex and its relatively low iron content have hampered in vivo study of cortical iron accumulation. Using phase images of a T2*-weighted sequence at ultrahigh field strength (7 Tesla), we examined the iron content of 22 cortical regions in 70 healthy subjects aged 22-80 years. The cortex was automatically segmented and parcellated, and phase shift was analyzed using an in-house developed method. We found a significant increase in phase shift with age in 20 of 22 cortical regions, concurrent with current understanding of cortical iron accumulation. Our findings suggest that increased cortical iron content can be assessed in healthy aging in vivo. The high spatial resolution and sensitivity to iron of our method make it a potentially useful tool for studying cortical iron accumulation in healthy aging and neurodegenerative diseases.
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Affiliation(s)
- Mathijs Buijs
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands; C.J. Gorter Center for High-field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
| | - Nhat Trung Doan
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands; Division of Image Processing (LKEB), Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Sanneke van Rooden
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands; C.J. Gorter Center for High-field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Maarten J Versluis
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands; C.J. Gorter Center for High-field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Baldur van Lew
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands; Division of Image Processing (LKEB), Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Julien Milles
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands; Division of Image Processing (LKEB), Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Jeroen van der Grond
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Mark A van Buchem
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands; C.J. Gorter Center for High-field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
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126
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Parmalee NL, Aschner M. Manganese and aging. Neurotoxicology 2016; 56:262-268. [PMID: 27293182 DOI: 10.1016/j.neuro.2016.06.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 06/04/2016] [Accepted: 06/05/2016] [Indexed: 12/11/2022]
Abstract
Manganese (Mn) is an essential metal that is required as a cofactor for many enzymes and is necessary for optimal biological function. Mn is abundant in the earth's crust and is present in soil and well water. Mn is also found in industrial settings, including mining, welding, and battery manufacture. Mn is also present in infant formula, parenteral nutrition, as well as pesticides and gasoline additives. A sufficient amount of Mn is obtained from most diets, and Mn deficiency is exceedingly rare. Excessive exposure to Mn in high doses can result in a condition known as manganism that results in psychological and emotional disturbances and motor symptoms that are reminiscent of Parkinson's disease, including gait disturbance, tremor, rigidity, and bradykinesia. Treatment for manganism is to remove the patient from Mn exposure, though symptoms are generally irreversible. The effects of exposure to Mn at lower doses are less clear. Little work has been done to evaluate the effects of chronic exposure to subclinical levels of Mn, especially in regard to lifelong exposures and the effects on the aging process. Mn is known to have effects on some of the same mechanistic processes that are altered in aging. This review will describe the general effects of Mn exposure and will focus on how Mn may be related to some of the mechanism of aging: neurogenesis, oxidative stress, and microglial activation and inflammation.
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Affiliation(s)
- Nancy L Parmalee
- Albert Einstein College of Medicine, Department of Molecular Pharmacology, 1300 Morris Park Avenue, Bronx, NY, United States.
| | - Michael Aschner
- Albert Einstein College of Medicine, Department of Molecular Pharmacology, 1300 Morris Park Avenue, Bronx, NY, United States.
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127
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Hernandez A, Donovan V, Grinberg YY, Obenaus A, Carson MJ. Differential detection of impact site versus rotational site injury by magnetic resonance imaging and microglial morphology in an unrestrained mild closed head injury model. J Neurochem 2016; 136 Suppl 1:18-28. [PMID: 26806371 PMCID: PMC5047732 DOI: 10.1111/jnc.13402] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/05/2015] [Accepted: 10/06/2015] [Indexed: 01/31/2023]
Abstract
Seventy‐five percent of all traumatic brain injuries are mild and do not cause readily visible abnormalities on routine medical imaging making it difficult to predict which individuals will develop unwanted clinical sequelae. Microglia are brain‐resident macrophages and early responders to brain insults. Their activation is associated with changes in morphology or expression of phenotypic markers including P2Y12 and major histocompatibility complex class II. Using a murine model of unrestrained mild closed head injury (mCHI), we used microglia as reporters of acute brain injury at sites of impact versus sites experiencing rotational stress 24 h post‐mCHI. Consistent with mild injury, a modest 20% reduction in P2Y12 expression was detected by quantitative real‐time PCR (qPCR) analysis but only in the impacted region of the cortex. Furthermore, neither an influx of blood‐derived immune cells nor changes in microglial expression of CD45, TREM1, TREM2, major histocompatibility complex class II or CD40 were detected. Using magnetic resonance imaging (MRI), small reductions in T2 weighted values were observed but only near the area of impact and without overt tissue damage (blood deposition, edema). Microglial morphology was quantified without cryosectioning artifacts using ScaleA2 clarified brains from CX3CR1‐green fluorescence protein (GFP) mice. The cortex rostral to the mCHI impact site receives greater rotational stress but neither MRI nor molecular markers of microglial activation showed significant changes from shams in this region. However, microglia in this rostral region did display signs of morphologic activation equivalent to that observed in severe CHI. Thus, mCHI‐triggered rotational stress is sufficient to cause injuries undetectable by routine MRI that could result in altered microglial surveillance of brain homeostasis.
Acute changes in microglial morphology reveal brain responses to unrestrained mild traumatic brain injury
In areas subjected to rotational stress distant from impact site In the absence of detectable changes in standard molecular indicators of brain damage, inflammation or microglial activation. That might result in decreased surveillance of brain function and increased susceptibility to subsequent brain insults.
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Affiliation(s)
- Alfredo Hernandez
- Center for Glial-Neuronal Interactions, University of California Riverside, School of Medicine, Riverside, California, USA.,MarcU Program, University of California Riverside, Riverside, California, USA.,Division of Biomedical Sciences, University of California Riverside, School of Medicine, Riverside, California, USA
| | - Virgina Donovan
- Center for Glial-Neuronal Interactions, University of California Riverside, School of Medicine, Riverside, California, USA.,Division of Biomedical Sciences, University of California Riverside, School of Medicine, Riverside, California, USA.,Cell Molecular and Developmental Biology Program, University of California Riverside, Riverside, California, USA.,Loma Linda University School of Medicine, Loma Linda California, Loma Linda, CA, USA
| | - Yelena Y Grinberg
- Center for Glial-Neuronal Interactions, University of California Riverside, School of Medicine, Riverside, California, USA.,Division of Biomedical Sciences, University of California Riverside, School of Medicine, Riverside, California, USA
| | - Andre Obenaus
- Center for Glial-Neuronal Interactions, University of California Riverside, School of Medicine, Riverside, California, USA.,Cell Molecular and Developmental Biology Program, University of California Riverside, Riverside, California, USA.,Loma Linda University School of Medicine, Loma Linda California, Loma Linda, CA, USA
| | - Monica J Carson
- Center for Glial-Neuronal Interactions, University of California Riverside, School of Medicine, Riverside, California, USA.,Division of Biomedical Sciences, University of California Riverside, School of Medicine, Riverside, California, USA.,Cell Molecular and Developmental Biology Program, University of California Riverside, Riverside, California, USA
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128
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Herbert J, Lucassen PJ. Depression as a risk factor for Alzheimer's disease: Genes, steroids, cytokines and neurogenesis - What do we need to know? Front Neuroendocrinol 2016; 41:153-71. [PMID: 26746105 DOI: 10.1016/j.yfrne.2015.12.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/23/2015] [Accepted: 12/27/2015] [Indexed: 01/18/2023]
Abstract
Depression (MDD) is prodromal to, and a component of, Alzheimer's disease (AD): it may also be a trigger for incipient AD. MDD is not a unitary disorder, so there may be particular subtypes of early life MDD that pose independent high risks for later AD, though the identification of these subtypes is problematical. There may either be a common pathological event underlying both MDD and AD, or MDD may sensitize the brain to a second event ('hit') that precipitates AD. MDD may also accelerate brain ageing, including altered DNA methylation, increased cortisol but decreasing DHEA and thus the risk for AD. So far, genes predicting AD (e.g. APOEε4) are not risk factors for MDD, and those implicated in MDD (e.g. SLC6A4) are not risks for AD, so a common genetic predisposition looks unlikely. There is as yet no strong indication that an epigenetic event occurs during some forms of MDD that predisposes to later AD, though the evidence is limited. Glucocorticoids (GCs) are disturbed in some cases of MDD and in AD. GCs have marked degenerative actions on the hippocampus, a site of early β-amyloid deposition, and rare genetic variants of GC-regulating enzymes (e.g. 11β-HSD) predispose to AD. GCs also inhibit hippocampal neurogenesis and plasticity, and thus episodic memory, a core symptom of AD. Disordered GCs in MDD may inhibit neurogenesis, but the contribution of diminished neurogenesis to the onset or progression of AD is still debated. GCs and cytokines also reduce BDNF, implicated in both MDD and AD and hippocampal neurogenesis, reinforcing the notion that those cases of MDD with disordered GCs may be a risk for AD. Cytokines, including IL1β, IL6 and TNFα, are increased in the blood in some cases of MDD. They also reduce hippocampal neurogenesis, and increased cytokines are a known risk for later AD. Inflammatory changes occur in both MDD and AD (e.g. raised CRP, TNFα). Both cytokines and GCs can have pro-inflammatory actions in the brain. Inflammation (e.g. microglial activation) may be a common link, but this has not been systematically investigated. We lack substantial, rigorous and comprehensive follow-up studies to better identify possible subtypes of MDD that may represent a major predictor for later AD. This would enable specific interventions during critical episodes of these subtypes of MDD that should reduce this substantial risk.
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Affiliation(s)
- Joe Herbert
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, UK.
| | - Paul J Lucassen
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, The Netherlands
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129
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Dugue R, Barone FC. Ischemic, traumatic and neurodegenerative brain inflammatory changes. FUTURE NEUROLOGY 2016. [DOI: 10.2217/fnl.16.5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This review serves to link the role of the immune system in the neuropathology of acute ischemic stroke, traumatic brain injury and neurodegenerative disease. The blood–brain barrier delineates the CNS from the peripheral immune system. However, the blood–cerebrospinal fluid barrier acts as a gate between the periphery and the brain, permitting immune activity crosstalk and modulation. In acute ischemic stroke, traumatic brain injury and other neurodegenerative diseases, the blood–brain barrier is compromised and an influx of inflammatory cells and plasma proteins occurs, resulting in edema, demyelination, cell dysfunction and death, and neurobehavioral changes. The role of the complement system, key cytokines, microglia and other neuroglia in brain degenerative pathology will be discussed.
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Affiliation(s)
- Rachelle Dugue
- Departments of Neurology & Physiology & Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA
| | - Frank C Barone
- Departments of Neurology & Physiology & Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA
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130
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Rawji KS, Mishra MK, Michaels NJ, Rivest S, Stys PK, Yong VW. Immunosenescence of microglia and macrophages: impact on the ageing central nervous system. Brain 2016; 139:653-61. [PMID: 26912633 DOI: 10.1093/brain/awv395] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 11/18/2015] [Indexed: 01/21/2023] Open
Abstract
Ageing of the central nervous system results in a loss of both grey and white matter, leading to cognitive decline. Additional injury to both the grey and white matter is documented in many neurological disorders with ageing, including Alzheimer's disease, traumatic brain and spinal cord injury, stroke, and multiple sclerosis. Accompanying neuronal and glial damage is an inflammatory response consisting of activated macrophages and microglia, innate immune cells demonstrated to be both beneficial and detrimental in neurological repair. This article will propose the following: (i) infiltrating macrophages age differently from central nervous system-intrinsic microglia; (ii) several mechanisms underlie the differential ageing process of these two distinct cell types; and (iii) therapeutic strategies that selectively target these diverse mechanisms may rejuvenate macrophages and microglia for repair in the ageing central nervous system. Most responses of macrophages are diminished with senescence, but activated microglia increase their expression of pro-inflammatory cytokines while diminishing chemotactic and phagocytic activities. The senescence of macrophages and microglia has a negative impact on several neurological diseases, and the mechanisms underlying their age-dependent phenotypic changes vary from extrinsic microenvironmental changes to intrinsic changes in genomic integrity. We discuss the negative effects of age on neurological diseases, examine the response of senescent macrophages and microglia in these conditions, and propose a theoretical framework of therapeutic strategies that target the different mechanisms contributing to the ageing phenotype in these two distinct cell types. Rejuvenation of ageing macrophage/microglia may preserve neurological integrity and promote regeneration in the ageing central nervous system.
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Affiliation(s)
- Khalil S Rawji
- 1 Hotchkiss Brain Institute and the Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Manoj K Mishra
- 1 Hotchkiss Brain Institute and the Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Nathan J Michaels
- 1 Hotchkiss Brain Institute and the Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Serge Rivest
- 2 Neuroscience Laboratory, CHU de Québec Research Centre, Department of Molecular Medicine, Faculty of Medicine, Laval University, Québec City, Québec G1V 4G2, Canada
| | - Peter K Stys
- 1 Hotchkiss Brain Institute and the Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - V Wee Yong
- 1 Hotchkiss Brain Institute and the Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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131
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Shan L, Tao EX, Meng QH, Hou WX, Liu K, Shang HC, Tang JB, Zhang WF. Formulation, optimization, and pharmacodynamic evaluation of chitosan/phospholipid/β-cyclodextrin microspheres. DRUG DESIGN DEVELOPMENT AND THERAPY 2016; 10:417-29. [PMID: 26869763 PMCID: PMC4734723 DOI: 10.2147/dddt.s97982] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cholinergic neurotransmission loss is the main cause of cognitive impairment in patients with Alzheimer's disease. Phospholipids (PLs) play an essential role in memory and learning abilities. Moreover, PLs act as a source of choline in acetylcholine synthesis. This study aimed to prepare and optimize the formulation of chitosan/phospholipid/β-cyclodextrin (CTS/PL/β-CD) microspheres that can improve cognitive impairment. The CTS/PL/β-CD microspheres were prepared by spray drying, and optimized with an orthogonal design. These microspheres were also characterized in terms of morphology, structure, thermostability, drug loading, and encapsulation efficiency. The spatial learning and memory of rats were evaluated using the Morris water maze test, and the neuroprotective effects of the CTS/PL/β-CD micro-spheres were investigated by immunohistochemistry. Scanning electron microscopic images showed that the CTS/PL/β-CD microspheres were spherical with slightly wrinkled surfaces. Fourier transform infrared spectroscopy and differential scanning calorimetry proved that PLs formed hydrogen bonds with the amide group of CTS and the hydroxyl group of β-CD. The learning and memory abilities of rats in the treated group significantly improved compared with those in the model group. Immunohistochemical analysis revealed that treatment with the CTS/PL/β-CD microspheres attenuated the expression of protein kinase C-δ and inhibited the activation of microglias. These results suggest that the optimized microspheres have the potential to be used in the treatment of Alzheimer's disease.
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Affiliation(s)
- Lu Shan
- School of Pharmacy, Weifang Medical University, Weifang, People's Republic of China
| | - En-Xue Tao
- The Affiliated Hospital of Weifang Medical University, Weifang, People's Republic of China
| | - Qing-Hui Meng
- School of Nursing, Weifang Medical University, Weifang, People's Republic of China
| | - Wen-Xia Hou
- School of Nursing, Weifang Medical University, Weifang, People's Republic of China
| | - Kang Liu
- School of Pharmacy, Weifang Medical University, Weifang, People's Republic of China
| | - Hong-Cai Shang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, People's Republic of China
| | - Jin-Bao Tang
- School of Pharmacy, Weifang Medical University, Weifang, People's Republic of China
| | - Wei-Fen Zhang
- School of Pharmacy, Weifang Medical University, Weifang, People's Republic of China; Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, People's Republic of China
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132
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von Bernhardi R, Heredia F, Salgado N, Muñoz P. Microglia Function in the Normal Brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 949:67-92. [PMID: 27714685 DOI: 10.1007/978-3-319-40764-7_4] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The activation of microglia has been recognized for over a century by their morphological changes. Long slender microglia acquire a short sturdy ramified shape when activated. During the past 20 years, microglia have been accepted as an essential cellular component for understanding the pathogenic mechanism of many brain diseases, including neurodegenerative diseases. More recently, functional studies and imaging in mouse models indicate that microglia are active in the healthy central nervous system. It has become evident that microglia release several signal molecules that play key roles in the crosstalk among brain cells, i.e., astrocytes and oligodendrocytes with neurons, as well as with regulatory immune cells. Recent studies also reveal the heterogeneous nature of microglia diverse functions depending on development, previous exposure to stimulation events, brain region of residence, or pathological state. Subjects to approach by future research are still the unresolved questions regarding the conditions and mechanisms that render microglia protective, capable of preventing or reducing damage, or deleterious, capable of inducing or facilitating the progression of neuropathological diseases. This novel knowledge will certainly change our view on microglia as therapeutic target, shifting our goal from their general silencing to the generation of treatments able to change their activation pattern.
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Affiliation(s)
- Rommy von Bernhardi
- Escuela de Medicina. Departamento de Neurología, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile.
| | - Florencia Heredia
- Escuela de Medicina. Departamento de Neurología, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Nicole Salgado
- Escuela de Medicina. Departamento de Neurología, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Paola Muñoz
- Escuela de Medicina. Departamento de Neurología, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
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133
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DeCarolis NA, Kirby ED, Wyss-Coray T, Palmer TD. The Role of the Microenvironmental Niche in Declining Stem-Cell Functions Associated with Biological Aging. Cold Spring Harb Perspect Med 2015; 5:5/12/a025874. [PMID: 26627453 DOI: 10.1101/cshperspect.a025874] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aging is strongly correlated with decreases in neurogenesis, the process by which neural stem and progenitor cells proliferate and differentiate into new neurons. In addition to stem-cell-intrinsic factors that change within the aging stem-cell pool, recent evidence emphasizes new roles for systemic and microenvironmental factors in modulating the neurogenic niche. This article focuses on new insights gained through the use of heterochronic parabiosis models, in which an old mouse and a young circulatory system are joined. By studying the brains of both young and old mice, researchers are beginning to uncover circulating proneurogenic "youthful" factors and "aging" factors that decrease stem-cell activity and neurogenesis. Ultimately, the identification of factors that influence stem-cell aging may lead to strategies that slow or even reverse age-related decreases in neural-stem-cell (NSC) function and neurogenesis.
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Affiliation(s)
- Nathan A DeCarolis
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94305
| | - Elizabeth D Kirby
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305 Center for Tissue Regeneration, Repair, and Restoration, Veterans Administration, Palo Alto Health Care Systems, Palo Alto, California 94304
| | - Theo D Palmer
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94305 Department of Neurosurgery, Stanford University School of Medicine, Stanford, California 94305
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134
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Friends or Foes: Matrix Metalloproteinases and Their Multifaceted Roles in Neurodegenerative Diseases. Mediators Inflamm 2015; 2015:620581. [PMID: 26538832 PMCID: PMC4619970 DOI: 10.1155/2015/620581] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 09/03/2015] [Accepted: 09/06/2015] [Indexed: 12/11/2022] Open
Abstract
Neurodegeneration is a chronic progressive loss of neuronal cells leading to deterioration of central nervous system (CNS) functionality. It has been shown that neuroinflammation precedes neurodegeneration in various neurodegenerative diseases. Matrix metalloproteinases (MMPs), a protein family of zinc-containing endopeptidases, are essential in (neuro)inflammation and might be involved in neurodegeneration. Although MMPs are indispensable for physiological development and functioning of the organism, they are often referred to as double-edged swords due to their ability to also inflict substantial damage in various pathological conditions. MMP activity is strictly controlled, and its dysregulation leads to a variety of pathologies. Investigation of their potential use as therapeutic targets requires a better understanding of their contributions to the development of neurodegenerative diseases. Here, we review MMPs and their roles in neurodegenerative diseases: Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and multiple sclerosis (MS). We also discuss MMP inhibition as a possible therapeutic strategy to treat neurodegenerative diseases.
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135
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Wehrspaun CC, Haerty W, Ponting CP. Microglia recapitulate a hematopoietic master regulator network in the aging human frontal cortex. Neurobiol Aging 2015; 36:2443.e9-2443.e20. [PMID: 26002684 PMCID: PMC4503803 DOI: 10.1016/j.neurobiolaging.2015.04.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/18/2015] [Accepted: 04/17/2015] [Indexed: 12/11/2022]
Abstract
Microglia form the immune system of the brain. Previous studies in cell cultures and animal models suggest altered activation states and cellular senescence in the aged brain. Instead, we analyzed 3 transcriptome data sets from the postmortem frontal cortex of 381 control individuals to show that microglia gene markers assemble into a transcriptional module in a gene coexpression network. These markers predominantly represented M1 and M1/M2b activation phenotypes. Expression of genes in this module generally declines over the adult life span. This decrease was more pronounced in microglia surface receptors for microglia and/or neuron crosstalk than in markers for activation state phenotypes. In addition to these receptors for exogenous signals, microglia are controlled by brain-expressed regulatory factors. We identified a subnetwork of transcription factors, including RUNX1, IRF8, PU.1, and TAL1, which are master regulators (MRs) for the age-dependent microglia module. The causal contributions of these MRs on the microglia module were verified using publicly available ChIP-Seq data. Interactions of these key MRs were preserved in a protein-protein interaction network. Importantly, these MRs appear to be essential for regulating microglia homeostasis in the adult human frontal cortex in addition to their crucial roles in hematopoiesis and myeloid cell-fate decisions during embryogenesis.
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Affiliation(s)
- Claudia C Wehrspaun
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK; Section on Neuropathology, Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, IRP, NIMH, NIH, Bethesda, MD, USA.
| | - Wilfried Haerty
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK; Department of Physiology, Anatomy and Genetics, MRC Functional Genomics Unit, University of Oxford, UK
| | - Chris P Ponting
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK; Department of Physiology, Anatomy and Genetics, MRC Functional Genomics Unit, University of Oxford, UK
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136
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von Bernhardi R, Eugenín-von Bernhardi L, Eugenín J. Microglial cell dysregulation in brain aging and neurodegeneration. Front Aging Neurosci 2015; 7:124. [PMID: 26257642 PMCID: PMC4507468 DOI: 10.3389/fnagi.2015.00124] [Citation(s) in RCA: 357] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Accepted: 06/22/2015] [Indexed: 12/29/2022] Open
Abstract
Aging is the main risk factor for neurodegenerative diseases. In aging, microglia undergoes phenotypic changes compatible with their activation. Glial activation can lead to neuroinflammation, which is increasingly accepted as part of the pathogenesis of neurodegenerative diseases, including Alzheimer’s disease (AD). We hypothesize that in aging, aberrant microglia activation leads to a deleterious environment and neurodegeneration. In aged mice, microglia exhibit an increased expression of cytokines and an exacerbated inflammatory response to pathological changes. Whereas LPS increases nitric oxide (NO) secretion in microglia from young mice, induction of reactive oxygen species (ROS) predominates in older mice. Furthermore, there is accumulation of DNA oxidative damage in mitochondria of microglia during aging, and also an increased intracellular ROS production. Increased ROS activates the redox-sensitive nuclear factor kappa B, which promotes more neuroinflammation, and can be translated in functional deficits, such as cognitive impairment. Mitochondria-derived ROS and cathepsin B, are also necessary for the microglial cell production of interleukin-1β, a key inflammatory cytokine. Interestingly, whereas the regulatory cytokine TGFβ1 is also increased in the aged brain, neuroinflammation persists. Assessing this apparent contradiction, we have reported that TGFβ1 induction and activation of Smad3 signaling after inflammatory stimulation are reduced in adult mice. Other protective functions, such as phagocytosis, although observed in aged animals, become not inducible by inflammatory stimuli and TGFβ1. Here, we discuss data suggesting that mitochondrial and endolysosomal dysfunction could at least partially mediate age-associated microglial cell changes, and, together with the impairment of the TGFβ1-Smad3 pathway, could result in the reduction of protective activation and the facilitation of cytotoxic activation of microglia, resulting in the promotion of neurodegenerative diseases.
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Affiliation(s)
- Rommy von Bernhardi
- Department of Neurology, Faculty of Medicine, Pontificia Universidad Católica de Chile Santiago, Chile
| | | | - Jaime Eugenín
- Laboratory of Neural Systems, Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile (USACH) Santiago, Chile
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137
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Deleidi M, Jäggle M, Rubino G. Immune aging, dysmetabolism, and inflammation in neurological diseases. Front Neurosci 2015; 9:172. [PMID: 26089771 PMCID: PMC4453474 DOI: 10.3389/fnins.2015.00172] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/28/2015] [Indexed: 12/17/2022] Open
Abstract
As we age, the immune system undergoes a process of senescence accompanied by the increased production of proinflammatory cytokines, a chronic subclinical condition named as “inflammaging”. Emerging evidence from human and experimental models suggest that immune senescence also affects the central nervous system and promotes neuronal dysfunction, especially within susceptible neuronal populations. In this review we discuss the potential role of immune aging, inflammation and metabolic derangement in neurological diseases. The discovery of novel therapeutic strategies targeting age-linked inflammation may promote healthy brain aging and the treatment of neurodegenerative as well as neuropsychiatric disorders.
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Affiliation(s)
- Michela Deleidi
- Department of Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Hertie Institute for Clinical Brain Research, University of Tübingen Tübingen, Germany
| | - Madeline Jäggle
- Department of Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Hertie Institute for Clinical Brain Research, University of Tübingen Tübingen, Germany
| | - Graziella Rubino
- Department of Internal Medicine II, Center for Medical Research, University of Tübingen Tübingen, Germany
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138
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Ojo JO, Rezaie P, Gabbott PL, Stewart MG. Impact of age-related neuroglial cell responses on hippocampal deterioration. Front Aging Neurosci 2015; 7:57. [PMID: 25972808 PMCID: PMC4413780 DOI: 10.3389/fnagi.2015.00057] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/04/2015] [Indexed: 12/25/2022] Open
Abstract
Aging is one of the greatest risk factors for the development of sporadic age-related neurodegenerative diseases and neuroinflammation is a common feature of this disease phenotype. In the immunoprivileged brain, neuroglial cells, which mediate neuroinflammatory responses, are influenced by the physiological factors in the microenvironment of the central nervous system (CNS). These physiological factors include but are not limited to cell-to-cell communication involving cell adhesion molecules, neuronal electrical activity and neurotransmitter and neuromodulator action. However, despite this dynamic control of neuroglial activity, in the healthy aged brain there is an alteration in the underlying neuroinflammatory response notably seen in the hippocampus, typified by astrocyte/microglia activation and increased pro-inflammatory cytokine production and signaling. These changes may occur without any overt concurrent pathology, however, they typically correlate with deteriorations in hippocamapal or cognitive function. In this review we examine two important phenomenons, firstly the relationship between age-related brain deterioration (focusing on hippocampal function) and underlying neuroglial response(s), and secondly how the latter affects molecular and cellular processes within the hippocampus that makes it vulnerable to age-related cognitive decline.
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Affiliation(s)
- Joseph O. Ojo
- Department of Life Sciences, The Open UniversityWalton Hall, UK
- Department of Neuropathology, Roskamp InstituteSarasota, FL, USA
| | - Payam Rezaie
- Department of Life Sciences, The Open UniversityWalton Hall, UK
| | - Paul L. Gabbott
- Department of Life Sciences, The Open UniversityWalton Hall, UK
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139
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Telomere dysfunction reduces microglial numbers without fully inducing an aging phenotype. Neurobiol Aging 2015; 36:2164-75. [PMID: 25892207 DOI: 10.1016/j.neurobiolaging.2015.03.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 03/03/2015] [Accepted: 03/10/2015] [Indexed: 12/16/2022]
Abstract
The susceptibility of the aging brain to neurodegenerative disease may in part be attributed to cellular aging of the microglial cells that survey it. We investigated the effect of cellular aging induced by telomere shortening on microglia by the use of mice lacking the telomerase RNA component (TERC) and design-based stereology. TERC knockout (KO) mice had a significantly reduced number of CD11b(+) microglia in the dentate gyrus. Because of an even greater reduction in dentate gyrus volume, microglial density was, however, increased. Microglia in TERC KO mice maintained a homogenous distribution and normal expression of CD45 and CD68 and the aging marker, ferritin, but were morphologically distinct from microglia in both adult and old wild-type mice. TERC KO mice also showed increased cellular apoptosis and impaired spatial learning. Our results suggest that individual microglia are relatively resistant to telomerase deficiency during steady state conditions, despite an overall reduction in microglial numbers. Furthermore, telomerase deficiency and aging may provide disparate cues leading to distinct changes in microglial morphology and phenotype.
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140
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Doorn KJ, Brevé JJP, Drukarch B, Boddeke HW, Huitinga I, Lucassen PJ, van Dam AM. Brain region-specific gene expression profiles in freshly isolated rat microglia. Front Cell Neurosci 2015; 9:84. [PMID: 25814934 PMCID: PMC4357261 DOI: 10.3389/fncel.2015.00084] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/23/2015] [Indexed: 12/30/2022] Open
Abstract
Microglia are important cells in the brain that can acquire different morphological and functional phenotypes dependent on the local situation they encounter. Knowledge on the region-specific gene signature of microglia may hold valuable clues for microglial functioning in health and disease, e.g., Parkinson's disease (PD) in which microglial phenotypes differ between affected brain regions. Therefore, we here investigated whether regional differences exist in gene expression profiles of microglia that are isolated from healthy rat brain regions relevant for PD. We used an optimized isolation protocol based on a rapid isolation of microglia from discrete rat gray matter regions using density gradients and fluorescent-activated cell sorting. Application of the present protocol followed by gene expression analysis enabled us to identify subtle differences in region-specific microglial expression profiles and show that the genetic profile of microglia already differs between different brain regions when studied under control conditions. As such, these novel findings imply that brain region-specific microglial gene expression profiles exist that may contribute to the region-specific differences in microglia responsivity during disease conditions, such as seen in, e.g., PD.
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Affiliation(s)
- Karlijn J Doorn
- Department Structural and Functional Plasticity of the Nervous System, Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands ; Neuroscience Campus Amsterdam, Department Anatomy and Neurosciences, VU University Medical Center Amsterdam, Netherlands
| | - John J P Brevé
- Neuroscience Campus Amsterdam, Department Anatomy and Neurosciences, VU University Medical Center Amsterdam, Netherlands
| | - Benjamin Drukarch
- Neuroscience Campus Amsterdam, Department Anatomy and Neurosciences, VU University Medical Center Amsterdam, Netherlands
| | - Hendrikus W Boddeke
- Section Medical Physiology, Department of Neuroscience, University Medical Centre Groningen Groningen, Netherlands
| | - Inge Huitinga
- Neuroimmunology Group, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences Amsterdam, Netherlands
| | - Paul J Lucassen
- Department Structural and Functional Plasticity of the Nervous System, Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Anne-Marie van Dam
- Department Structural and Functional Plasticity of the Nervous System, Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
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141
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Dey A, Allen J, Hankey-Giblin PA. Ontogeny and polarization of macrophages in inflammation: blood monocytes versus tissue macrophages. Front Immunol 2015; 5:683. [PMID: 25657646 PMCID: PMC4303141 DOI: 10.3389/fimmu.2014.00683] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 12/17/2014] [Indexed: 12/23/2022] Open
Abstract
The explosion of new information in recent years on the origin of macrophages in the steady-state and in the context of inflammation has opened up numerous new avenues of investigation and possibilities for therapeutic intervention. In contrast to the classical model of macrophage development, it is clear that tissue-resident macrophages can develop from yolk sac-derived erythro-myeloid progenitors, fetal liver progenitors, and bone marrow-derived monocytes. Under both homeostatic conditions and in response to pathophysiological insult, the contribution of these distinct sources of macrophages varies significantly between tissues. Furthermore, while all of these populations of macrophages appear to be capable of adopting the polarized M1/M2 phenotypes, their respective contribution to inflammation, resolution of inflammation, and tissue repair remains poorly understood and is likely to be tissue- and disease-dependent. A better understanding of the ontology and polarization capacity of macrophages in homeostasis and disease will be essential for the development of novel therapies that target the inherent plasticity of macrophages in the treatment of acute and chronic inflammatory disease.
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Affiliation(s)
- Adwitia Dey
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, PA , USA ; Graduate Program in Physiology, The Pennsylvania State University , University Park, PA , USA
| | - Joselyn Allen
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, PA , USA ; Graduate Program in Immunology and Infectious Disease, The Pennsylvania State University , University Park, PA , USA
| | - Pamela A Hankey-Giblin
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, PA , USA ; Graduate Program in Physiology, The Pennsylvania State University , University Park, PA , USA ; Graduate Program in Immunology and Infectious Disease, The Pennsylvania State University , University Park, PA , USA
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142
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Migration and Phagocytic Ability of Activated Microglia During Post-natal Development is Mediated by Calcium-Dependent Purinergic Signalling. Mol Neurobiol 2015; 53:944-954. [PMID: 25575683 DOI: 10.1007/s12035-014-9064-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/09/2014] [Indexed: 01/10/2023]
Abstract
Microglia play an important role in synaptic pruning and controlled phagocytosis of neuronal cells during developmental stages. However, the mechanisms that regulate these functions are not completely understood. The present study was designed to investigate the role of purinergic signalling in microglial migration and phagocytic activity during post-natal brain development. One-day-old BALB/c mice received lipopolysaccharide (LPS) and/or a purinergic analogue (2-methylthioladenosine-5'-diphosphate; 2MeSADP), intracerebroventrically (i.c.v.). Combined administration of LPS and 2MeSADP resulted in activation of microglia as evident from increased expression of ionised calcium-binding adapter molecule 1 (Iba1). Activated microglia showed increased expression of purinergic receptors (P2Y2, P2Y6 and P2Y12). LPS either alone or in combination with 2MeSADP induced the expression of Na(+)/Ca(2+) exchanger (NCX-1) and P/Q-type Ca(2+) channels along with MARCKS-related protein (MRP), which is an integral component of cell migration machinery. In addition, LPS and 2MeSADP administration induced the expression of microglial CD11b and DAP12 (DNAX-activation protein 12), which are known to be involved in phagocytosis of neurons during development. Interestingly, administration of thapsigargin (TG), a specific Ca(2+)-ATPase inhibitor of endoplasmic reticulum, prevented the LPS/2MeSADP-induced microglial activation and migration by down-regulating the expression of Iba1 and MRP, respectively. Moreover, TG also reduced the LPS/2MeSADP-induced expression of CD11b/DAP12. Taken together, the findings reveal for the first time that Ca(2+)-mediated purinergic receptors regulate the migration and phagocytic ability of microglia during post-natal brain development.
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143
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Abstract
Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide. Despite extensive preclinical research supporting the effectiveness of neuroprotective therapies for brain trauma, there have been no successful randomized controlled clinical trials to date. TBI results in delayed secondary tissue injury due to neurochemical, metabolic and cellular changes; modulating such effects has provided the basis for neuroprotective interventions. To establish more effective neuroprotective treatments for TBI it is essential to better understand the complex cellular and molecular events that contribute to secondary injury. Here we critically review relevant research related to causes and modulation of delayed tissue damage, with particular emphasis on cell death mechanisms and post-traumatic neuroinflammation. We discuss the concept of utilizing multipotential drugs that target multiple secondary injury pathways, rather than more specific "laser"-targeted strategies that have uniformly failed in clinical trials. Moreover, we assess data supporting use of neuroprotective drugs that are currently being evaluated in human clinical trials for TBI, as well as promising emerging experimental multipotential drug treatment strategies. Finally, we describe key challenges and provide suggestions to improve the likelihood of successful clinical translation.
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Affiliation(s)
- David J Loane
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), National Study Center for Trauma and EMS, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bogdan A Stoica
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), National Study Center for Trauma and EMS, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alan I Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), National Study Center for Trauma and EMS, University of Maryland School of Medicine, Baltimore, MD, USA.
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144
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White matter tract and glial-associated changes in 5-hydroxymethylcytosine following chronic cerebral hypoperfusion. Brain Res 2014; 1592:82-100. [DOI: 10.1016/j.brainres.2014.09.060] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 12/26/2022]
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145
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Ward RJ, Zucca FA, Duyn JH, Crichton RR, Zecca L. The role of iron in brain ageing and neurodegenerative disorders. Lancet Neurol 2014; 13:1045-60. [PMID: 25231526 DOI: 10.1016/s1474-4422(14)70117-6] [Citation(s) in RCA: 1127] [Impact Index Per Article: 112.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
SUMMARY In the CNS, iron in several proteins is involved in many important processes such as oxygen transportation, oxidative phosphorylation, myelin production, and the synthesis and metabolism of neurotransmitters. Abnormal iron homoeostasis can induce cellular damage through hydroxyl radical production, which can cause the oxidation and modification of lipids, proteins, carbohydrates, and DNA. During ageing, different iron complexes accumulate in brain regions associated with motor and cognitive impairment. In various neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, changes in iron homoeostasis result in altered cellular iron distribution and accumulation. MRI can often identify these changes, thus providing a potential diagnostic biomarker of neurodegenerative diseases. An important avenue to reduce iron accumulation is the use of iron chelators that are able to cross the blood-brain barrier, penetrate cells, and reduce excessive iron accumulation, thereby affording neuroprotection.
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Affiliation(s)
- Roberta J Ward
- Centre for Neuroinflammation and Neurodegeneration, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London, UK; Faculte de Science, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Fabio A Zucca
- Institute of Biomedical Technologies, National Research Council of Italy, Segrate, Milan, Italy
| | - Jeff H Duyn
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Robert R Crichton
- Faculte de Science, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Luigi Zecca
- Institute of Biomedical Technologies, National Research Council of Italy, Segrate, Milan, Italy.
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146
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Are there roles for brain cell senescence in aging and neurodegenerative disorders? Biogerontology 2014; 15:643-60. [PMID: 25305051 DOI: 10.1007/s10522-014-9532-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 09/13/2014] [Indexed: 12/30/2022]
Abstract
The term cellular senescence was introduced more than five decades ago to describe the state of growth arrest observed in aging cells. Since this initial discovery, the phenotypes associated with cellular senescence have expanded beyond growth arrest to include alterations in cellular metabolism, secreted cytokines, epigenetic regulation and protein expression. Recently, senescence has been shown to play an important role in vivo not only in relation to aging, but also during embryonic development. Thus, cellular senescence serves different purposes and comprises a wide range of distinct phenotypes across multiple cell types. Whether all cell types, including post-mitotic neurons, are capable of entering into a senescent state remains unclear. In this review we examine recent data that suggest that cellular senescence plays a role in brain aging and, notably, may not be limited to glia but also neurons. We suggest that there is a high level of similarity between some of the pathological changes that occur in the brain in Alzheimer's and Parkinson's diseases and those phenotypes observed in cellular senescence, leading us to propose that neurons and glia can exhibit hallmarks of senescence previously documented in peripheral tissues.
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147
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Singhal G, Jaehne EJ, Corrigan F, Toben C, Baune BT. Inflammasomes in neuroinflammation and changes in brain function: a focused review. Front Neurosci 2014; 8:315. [PMID: 25339862 PMCID: PMC4188030 DOI: 10.3389/fnins.2014.00315] [Citation(s) in RCA: 252] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 09/18/2014] [Indexed: 12/11/2022] Open
Abstract
Recent literature has pointed to the existence of inflammasome-mediated inflammatory pathways in central nervous system (CNS) disorders and associated changes in behavior. Neuroinflammation, which is an innate immune response in the CNS against harmful and irritable stimuli such as pathogens and metabolic toxic waste, as well as to chronic mild stress, is mediated by protein complexes known as inflammasomes. Inflammasomes activate pro-inflammatory caspases 1 and 5, which then cleave the precursor forms of pro-inflammatory cytokines IL-1β, IL-18, and IL-33 into their active forms. These pro-inflammatory cytokines have been shown to promote a variety of innate immune processes associated with infection, inflammation, and autoimmunity, and thereby play an instrumental role in the instigation of neuroinflammation during old age and subsequent occurrence of neurodegenerative diseases, cognitive impairment, and dementia. In particular, NLRP inflammasomes may also have a role in the etiologies of depression, Alzheimer's disease (AD) and in metabolic disorders, such as Type II diabetes, obesity and cardiovascular diseases that have been shown to be co-morbid with psychiatric illnesses. It has been reported that while these inflammasomes may be activated through TNF-α dependent pathways, other cytokines, like IFN-γ, may assist in inhibiting their activation and thus delay disease progression. Furthermore, some other cytokines, including IL-6, may not have a direct role in inflammasome-mediated diseases. An array of recent research suggests that NLRP inflammasomes targeted therapies could be used for alleviating neuroinflammation and for treatment of associated psychiatric illnesses, although this still remains a challenge and necessitates further extensive research. This review examines the complex inflammatory signaling pathways involved in the activation of NLRP inflammasomes and the role they play in promoting neuroinflammation and subsequent behavioral changes.
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Affiliation(s)
- Gaurav Singhal
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, School of Medicine, University of AdelaideAdelaide, SA, Australia
| | - Emily J. Jaehne
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, School of Medicine, University of AdelaideAdelaide, SA, Australia
| | - Frances Corrigan
- Discipline of Anatomy and Physiology, School of Medical Sciences, University of AdelaideAdelaide, SA, Australia
| | - Catherine Toben
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, School of Medicine, University of AdelaideAdelaide, SA, Australia
| | - Bernhard T. Baune
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, School of Medicine, University of AdelaideAdelaide, SA, Australia
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148
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Liao SQ, Li JC, Zhang M, Wang YJ, Li BH, Yin YW, Liu Y, Gao CY, Zhang LL. The association between leukoaraiosis and carotid atherosclerosis: a systematic review and meta-analysis. Int J Neurosci 2014; 125:493-500. [PMID: 25164096 DOI: 10.3109/00207454.2014.949703] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The association between large-artery atherosclerosis and leukoaraiosis (LA) has been increasingly reported with inconsistent conclusion. This systematic review examines the relationship between LA and carotid atherosclerosis, manifested as atherosclerotic stenosis, plaques and increased intima-media thickness (IMT). PubMed, Embase, and Web of Science were searched for articles published up to February 2014. Thirty-two studies that examined the relationship between LA and carotid atherosclerosis were included. All statistical analysis was conducted with Review Manager 5.2.4. Finally, 32 studies including 17,721 patients were identified. There were 7 (30%) out of 23 studies reporting significant association between LA and carotid stenosis; 11 (79%) out of 14 studies reporting significant association between LA and carotid plaque; all 9 studies reporting significant association between LA and carotid IMT; one study showing an association between LA and CAWT (similar to the role of the IMT). The quantitative meta-analysis of 10 studies showed that carotid atherosclerosis was not associated with LA (OR: 1.10; 95% CI: 0.61-1.98). A significant association was found between LA and carotid plaque (OR = 3.53; 95% CI = 1.83-6.79), and the result of IMT group showed that IMT increased risk of LA (MD = 0.11; 95% CI = 0.01-0.22). This systematic review suggested that LA has a tendency of association with carotid plaques but no association with simple carotid stenosis.
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Affiliation(s)
- Shao-Qiong Liao
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing 400042, P.R. China
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149
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Noh H, Park C, Park S, Lee YS, Cho SY, Seo H. Prediction of miRNA-mRNA associations in Alzheimer's disease mice using network topology. BMC Genomics 2014; 15:644. [PMID: 25086961 PMCID: PMC4132902 DOI: 10.1186/1471-2164-15-644] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 07/08/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Little is known about the relationship between miRNA and mRNA expression in Alzheimer's disease (AD) at early- or late-symptomatic stages. Sequence-based target prediction algorithms and anti-correlation profiles have been applied to predict miRNA targets using omics data, but this approach often leads to false positive predictions. Here, we applied the joint profiling analysis of mRNA and miRNA expression levels to Tg6799 AD model mice at 4 and 8 months of age using a network topology-based method. We constructed gene regulatory networks and used the PageRank algorithm to predict significant interactions between miRNA and mRNA. RESULTS In total, 8 cluster modules were predicted by the transcriptome data for co-expression networks of AD pathology. In total, 54 miRNAs were identified as being differentially expressed in AD. Among these, 50 significant miRNA-mRNA interactions were predicted by integrating sequence target prediction, expression analysis, and the PageRank algorithm. We identified a set of miRNA-mRNA interactions that were changed in the hippocampus of Tg6799 AD model mice. We determined the expression levels of several candidate genes and miRNA. For functional validation in primary cultured neurons from Tg6799 mice (MT) and littermate (LM) controls, the overexpression of ARRDC3 enhanced PPP1R3C expression. ARRDC3 overexpression showed the tendency to decrease the expression of miR139-5p and miR3470a in both LM and MT primary cells. Pathological environment created by Aβ treatment increased the gene expression of PPP1R3C and Sfpq but did not significantly alter the expression of miR139-5p or miR3470a. Aβ treatment increased the promoter activity of ARRDC3 gene in LM primary cells but not in MT primary cells. CONCLUSIONS Our results demonstrate AD-specific changes in the miRNA regulatory system as well as the relationship between the expression levels of miRNAs and their targets in the hippocampus of Tg6799 mice. These data help further our understanding of the function and mechanism of various miRNAs and their target genes in the molecular pathology of AD.
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Affiliation(s)
| | | | | | | | - Soo Young Cho
- Department of Molecular & Life Sciences, Hanyang University, 1271 Sa-dong, Sangrok-gu, Ansan, Gyeonggi-do, South Korea.
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150
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Tanaka Y, Chambers JK, Matsuwaki T, Yamanouchi K, Nishihara M. Possible involvement of lysosomal dysfunction in pathological changes of the brain in aged progranulin-deficient mice. Acta Neuropathol Commun 2014; 2:78. [PMID: 25022663 PMCID: PMC4149276 DOI: 10.1186/s40478-014-0078-x] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 06/22/2014] [Indexed: 11/21/2022] Open
Abstract
Introduction It has been shown that progranulin (PGRN) deficiency causes age-related neurodegenerative diseases such as frontotemporal lobar degeneration (FTLD) and neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disease. Previous studies also suggested that PGRN is involved in modulating lysosomal function. To elucidate the pathophysiological role of PGRN in the aged brain, in the present study, lysosomal function and pathological changes of the brain were investigated using 10- and 90-week-old wild-type and PGRN-deficient mice. Results We showed that PGRN deficiency caused enhanced CD68 expression in activated microglia and astrogliosis in the cortex and thalamus, especially in the ventral posteromedial nucleus/ventral posterolateral nucleus (VPM/VPL), in the aged brain. Immunoreactivity for Lamp1 (lysosome marker) in the VPM/VPL and expression of lysosome-related genes, i.e. cathepsin D, V-type proton ATPase subunit d2, and transcription factor EB genes, were also increased by PGRN deficiency. Aggregates of p62, which is selectively degraded by the autophagy-lysosomal system, were observed in neuronal and glial cells in the VPM/VPL of aged PGRN-deficient mice. TAR DNA binding protein 43 (TDP-43) aggregates in the cytoplasm of neurons were also observed in aged PGRN-deficient mice. PGRN deficiency caused enhanced expression of glial cell-derived cytotoxic factors such as macrophage expressed gene 1, cytochrome b-245 light chain, cytochrome b-245 heavy chain, complement C4, tumor necrosis factor-α and lipocalin 2. In addition, neuronal loss and lipofuscinosis in the VPM/VPL and disrupted myelination in the cerebral cortex were observed in aged PGRN-deficient mice. Conclusions The present study shows that aged PGRN-deficient mice present with NCL-like pathology as well as TDP-43 aggregates in the VPM/VPL, where a particular vulnerability has been reported in NCL model mice. The present results also suggest that these pathological changes in the VPM/VPL are likely a result of lysosomal dysfunction. How PGRN prevents lysosomal dysfunction with aging remains to be elucidated. Electronic supplementary material The online version of this article (doi:10.1186/s40478-014-0078-x) contains supplementary material, which is available to authorized users.
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