151
|
Dashkoff J, Lerner EP, Truong N, Klickstein JA, Fan Z, Mu D, Maguire CA, Hyman BT, Hudry E. Tailored transgene expression to specific cell types in the central nervous system after peripheral injection with AAV9. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2016; 3:16081. [PMID: 27933308 PMCID: PMC5142512 DOI: 10.1038/mtm.2016.81] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/22/2016] [Accepted: 10/24/2016] [Indexed: 01/06/2023]
Abstract
The capacity of certain adeno-associated virus (AAV) vectors to cross the blood–brain barrier after intravenous delivery offers a unique opportunity for noninvasive brain delivery. However, without a well-tailored system, the use of a peripheral route injection may lead to undesirable transgene expression in nontarget cells or organs. To refine this approach, the present study characterizes the transduction profiles of new self-complementary AAV9 (scAAV9) expressing the green fluorescent protein (GFP) either under an astrocyte (glial fibrillary acidic (GFA) protein) or neuronal (Synapsin (Syn)) promoter, after intravenous injection of adult mice (2 × 1013 vg/kg). ScAAV9-GFA-GFP and scAAV9-Syn-GFP robustly transduce astrocytes (11%) and neurons (17%), respectively, without aberrant expression leakage. Interestingly, while the percentages of GFP-positive astrocytes with scAAV9-GFA-GFP are similar to the performances observed with scAAV9-CBA-GFP (broadly active promoter), significant higher percentages of neurons express GFP with scAAV9-Syn-GFP. GFP-positive excitatory as well as inhibitory neurons are observed, as well as motor neurons in the spinal cord. Additionally, both activated (GFAP-positive) and resting astrocytes (GFAP-negative) express the reporter gene after scAAV9-GFA-GFP injection. These data thoroughly characterize the gene expression specificity of AAVs fitted with neuronal and astrocyte-selective promoters after intravenous delivery, which will prove useful for central nervous system (CNS) gene therapy approaches in which peripheral expression of transgene is a concern.
Collapse
Affiliation(s)
- Jonathan Dashkoff
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, USA; MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Eli P Lerner
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School , Charlestown, Massachusetts, USA
| | - Nhi Truong
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School , Charlestown, Massachusetts, USA
| | - Jacob A Klickstein
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School , Charlestown, Massachusetts, USA
| | - Zhanyun Fan
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School , Charlestown, Massachusetts, USA
| | - Dakai Mu
- Department of Neurology, The Massachusetts General Hospital, and NeuroDiscovery Center, Harvard Medical School , Boston, Massachusetts, USA
| | - Casey A Maguire
- Department of Neurology, The Massachusetts General Hospital, and NeuroDiscovery Center, Harvard Medical School , Boston, Massachusetts, USA
| | - Bradley T Hyman
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School , Charlestown, Massachusetts, USA
| | - Eloise Hudry
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School , Charlestown, Massachusetts, USA
| |
Collapse
|
152
|
Iram T, Trudler D, Kain D, Kanner S, Galron R, Vassar R, Barzilai A, Blinder P, Fishelson Z, Frenkel D. Astrocytes from old Alzheimer's disease mice are impaired in Aβ uptake and in neuroprotection. Neurobiol Dis 2016; 96:84-94. [DOI: 10.1016/j.nbd.2016.08.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 07/11/2016] [Accepted: 08/16/2016] [Indexed: 10/21/2022] Open
|
153
|
Reemst K, Noctor SC, Lucassen PJ, Hol EM. The Indispensable Roles of Microglia and Astrocytes during Brain Development. Front Hum Neurosci 2016; 10:566. [PMID: 27877121 PMCID: PMC5099170 DOI: 10.3389/fnhum.2016.00566] [Citation(s) in RCA: 336] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/25/2016] [Indexed: 01/17/2023] Open
Abstract
Glia are essential for brain functioning during development and in the adult brain. Here, we discuss the various roles of both microglia and astrocytes, and their interactions during brain development. Although both cells are fundamentally different in origin and function, they often affect the same developmental processes such as neuro-/gliogenesis, angiogenesis, axonal outgrowth, synaptogenesis and synaptic pruning. Due to their important instructive roles in these processes, dysfunction of microglia or astrocytes during brain development could contribute to neurodevelopmental disorders and potentially even late-onset neuropathology. A better understanding of the origin, differentiation process and developmental functions of microglia and astrocytes will help to fully appreciate their role both in the developing as well as in the adult brain, in health and disease.
Collapse
Affiliation(s)
- Kitty Reemst
- Swammerdam Institute for Life Sciences, University of AmsterdamAmsterdam, Netherlands
| | - Stephen C. Noctor
- Department of Psychiatry and Behavioral Sciences, UC Davis MIND InstituteSacramento, CA, USA
| | - Paul J. Lucassen
- Swammerdam Institute for Life Sciences, University of AmsterdamAmsterdam, Netherlands
| | - Elly M. Hol
- Swammerdam Institute for Life Sciences, University of AmsterdamAmsterdam, Netherlands
- Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, Netherlands
- Netherlands Institute for NeuroscienceAmsterdam, Netherlands
| |
Collapse
|
154
|
Griffith CM, Xie MX, Qiu WY, Sharp AA, Ma C, Pan A, Yan XX, Patrylo PR. Aberrant expression of the pore-forming KATP channel subunit Kir6.2 in hippocampal reactive astrocytes in the 3xTg-AD mouse model and human Alzheimer’s disease. Neuroscience 2016; 336:81-101. [DOI: 10.1016/j.neuroscience.2016.08.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 08/15/2016] [Accepted: 08/20/2016] [Indexed: 12/21/2022]
|
155
|
Livne-Bar I, Lam S, Chan D, Guo X, Askar I, Nahirnyj A, Flanagan JG, Sivak JM. Pharmacologic inhibition of reactive gliosis blocks TNF-α-mediated neuronal apoptosis. Cell Death Dis 2016; 7:e2386. [PMID: 27685630 PMCID: PMC5059876 DOI: 10.1038/cddis.2016.277] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 07/25/2016] [Accepted: 07/29/2016] [Indexed: 01/03/2023]
Abstract
Reactive gliosis is an early pathological feature common to most neurodegenerative diseases, yet its regulation and impact remain poorly understood. Normally astrocytes maintain a critical homeostatic balance. After stress or injury they undergo rapid parainflammatory activation, characterized by hypertrophy, and increased polymerization of type III intermediate filaments (IFs), particularly glial fibrillary acidic protein and vimentin. However, the consequences of IF dynamics in the adult CNS remains unclear, and no pharmacologic tools have been available to target this mechanism in vivo. The mammalian retina is an accessible model to study the regulation of astrocyte stress responses, and their influence on retinal neuronal homeostasis. In particular, our work and others have implicated p38 mitogen-activated protein kinase (MAPK) signaling as a key regulator of glutamate recycling, antioxidant activity and cytokine secretion by astrocytes and related Müller glia, with potent influences on neighboring neurons. Here we report experiments with the small molecule inhibitor, withaferin A (WFA), to specifically block type III IF dynamics in vivo. WFA was administered in a model of metabolic retinal injury induced by kainic acid, and in combination with a recent model of debridement-induced astrocyte reactivity. We show that WFA specifically targets IFs and reduces astrocyte and Müller glial reactivity in vivo. Inhibition of glial IF polymerization blocked p38 MAPK-dependent secretion of TNF-α, resulting in markedly reduced neuronal apoptosis. To our knowledge this is the first study to demonstrate that pharmacologic inhibition of IF dynamics in reactive glia protects neurons in vivo.
Collapse
Affiliation(s)
- Izhar Livne-Bar
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,School of Optometry, University of California at Berkeley, Berkeley, CA, USA
| | - Susy Lam
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Darren Chan
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Xiaoxin Guo
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Idil Askar
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Adrian Nahirnyj
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - John G Flanagan
- School of Optometry, University of California at Berkeley, Berkeley, CA, USA
| | - Jeremy M Sivak
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
156
|
Verkhratsky A, Steardo L, Parpura V, Montana V. Translational potential of astrocytes in brain disorders. Prog Neurobiol 2016; 144:188-205. [PMID: 26386136 PMCID: PMC4794425 DOI: 10.1016/j.pneurobio.2015.09.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/03/2015] [Accepted: 09/08/2015] [Indexed: 12/11/2022]
Abstract
Fundamentally, all brain disorders can be broadly defined as the homeostatic failure of this organ. As the brain is composed of many different cells types, including but not limited to neurons and glia, it is only logical that all the cell types/constituents could play a role in health and disease. Yet, for a long time the sole conceptualization of brain pathology was focused on the well-being of neurons. Here, we challenge this neuron-centric view and present neuroglia as a key element in neuropathology, a process that has a toll on astrocytes, which undergo complex morpho-functional changes that can in turn affect the course of the disorder. Such changes can be grossly identified as reactivity, atrophy with loss of function and pathological remodeling. We outline the pathogenic potential of astrocytes in variety of disorders, ranging from neurotrauma, infection, toxic damage, stroke, epilepsy, neurodevelopmental, neurodegenerative and psychiatric disorders, Alexander disease to neoplastic changes seen in gliomas. We hope that in near future we would witness glial-based translational medicine with generation of deliverables for the containment and cure of disorders. We point out that such as a task will require a holistic and multi-disciplinary approach that will take in consideration the concerted operation of all the cell types in the brain.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Science, The University of Manchester, Manchester, UK
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Luca Steardo
- Department of Psychiatry, University of Naples, SUN, Largo Madonna delle Grazie, Naples, Italy
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine and Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Vedrana Montana
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| |
Collapse
|
157
|
Radulovic M, Yoon H, Wu J, Mustafa K, Scarisbrick IA. Targeting the thrombin receptor modulates inflammation and astrogliosis to improve recovery after spinal cord injury. Neurobiol Dis 2016; 93:226-42. [PMID: 27145117 PMCID: PMC4930708 DOI: 10.1016/j.nbd.2016.04.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 04/08/2016] [Accepted: 04/29/2016] [Indexed: 02/07/2023] Open
Abstract
The deregulation of serine protease activity is a common feature of neurological injury, but little is known regarding their mechanisms of action or whether they can be targeted to facilitate repair. In this study we demonstrate that the thrombin receptor (Protease Activated Receptor 1, (PAR1)) serves as a critical translator of the spinal cord injury (SCI) proteolytic microenvironment into a cascade of pro-inflammatory events that contribute to astrogliosis and functional decline. PAR1 knockout mice displayed improved locomotor recovery after SCI and reduced signatures of inflammation and astrogliosis, including expression of glial fibrillary acidic protein (GFAP), vimentin, and STAT3 signaling. SCI-associated elevations in pro-inflammatory cytokines such as IL-1β and IL-6 were also reduced in PAR1-/- mice and co-ordinate improvements in tissue sparing and preservation of NeuN-positive ventral horn neurons, and PKCγ corticospinal axons, were observed. PAR1 and its agonist's thrombin and neurosin were expressed by perilesional astrocytes and each agonist increased the production of IL-6 and STAT3 signaling in primary astrocyte cultures in a PAR1-dependent manner. In turn, IL-6-stimulated astrocytes increased expression of PAR1, thrombin, and neurosin, pointing to a model in which PAR1 activation contributes to increased astrogliosis by feedforward- and feedback-signaling dynamics. Collectively, these findings identify the thrombin receptor as a key mediator of inflammation and astrogliosis in the aftermath of SCI that can be targeted to reduce neurodegeneration and improve neurobehavioral recovery.
Collapse
Affiliation(s)
- Maja Radulovic
- Neurobiology of Disease Program, Mayo Medical and Graduate School, Rehabilitation Medicine Research Center, Rochester 55905, MN, United States
| | - Hyesook Yoon
- Department of Physical Medicine and Rehabilitation, Mayo Medical and Graduate School, Rehabilitation Medicine Research Center, Rochester, MN 55905, United States; Department of Physiology and Biomedical Engineering, Mayo Medical and Graduate School, Rehabilitation Medicine Research Center, Rochester, MN 55905, United States
| | - Jianmin Wu
- Department of Physical Medicine and Rehabilitation, Mayo Medical and Graduate School, Rehabilitation Medicine Research Center, Rochester, MN 55905, United States
| | - Karim Mustafa
- Neurobiology of Disease Program, Mayo Medical and Graduate School, Rehabilitation Medicine Research Center, Rochester 55905, MN, United States
| | - Isobel A Scarisbrick
- Neurobiology of Disease Program, Mayo Medical and Graduate School, Rehabilitation Medicine Research Center, Rochester 55905, MN, United States; Department of Physical Medicine and Rehabilitation, Mayo Medical and Graduate School, Rehabilitation Medicine Research Center, Rochester, MN 55905, United States; Department of Physiology and Biomedical Engineering, Mayo Medical and Graduate School, Rehabilitation Medicine Research Center, Rochester, MN 55905, United States.
| |
Collapse
|
158
|
Bolton Hall AN, Joseph B, Brelsfoard JM, Saatman KE. Repeated Closed Head Injury in Mice Results in Sustained Motor and Memory Deficits and Chronic Cellular Changes. PLoS One 2016; 11:e0159442. [PMID: 27427961 PMCID: PMC4948770 DOI: 10.1371/journal.pone.0159442] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/17/2016] [Indexed: 02/07/2023] Open
Abstract
Millions of mild traumatic brain injuries (TBIs) occur every year in the United States, with many people subject to multiple head injuries that can lead to chronic behavioral dysfunction. We previously reported that mild TBI induced using closed head injuries (CHI) repeated at 24h intervals produced more acute neuron death and glial reactivity than a single CHI, and increasing the length of time between injuries to 48h reduced the cumulative acute effects of repeated CHI. To determine whether repeated CHI is associated with behavioral dysfunction or persistent cellular damage, mice receiving either five CHI at 24h intervals, five CHI at 48h intervals, or five sham injuries at 24h intervals were evaluated across a 10 week period after injury. Animals with repeated CHI exhibited motor coordination and memory deficits, but not gait abnormalities when compared to sham animals. At 10wks post-injury, no notable neuron loss or glial reactivity was observed in the cortex, hippocampus, or corpus callosum. Argyrophilic axons were found in the pyramidal tract of some injured animals, but neither silver stain accumulation nor inflammatory responses in the injury groups were statistically different from the sham group in this region. However, argyrophilic axons, microgliosis and astrogliosis were significantly increased within the optic tract of injured animals. Repeated mild CHI also resulted in microgliosis and a loss of neurofilament protein 200 in the optic nerve. Lengthening the inter-injury interval from 24h to 48h did not effectively reduce these behavioral or cellular responses. These results suggest that repeated mild CHI results in persistent behavioral dysfunction and chronic pathological changes within the visual system, neither of which was significantly attenuated by lengthening the inter-injury interval from 24h to 48h.
Collapse
Affiliation(s)
- Amanda N. Bolton Hall
- Spinal Cord and Brain Injury Research Center, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
- Department of Physiology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Binoy Joseph
- Spinal Cord and Brain Injury Research Center, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Jennifer M. Brelsfoard
- Spinal Cord and Brain Injury Research Center, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| | - Kathryn E. Saatman
- Spinal Cord and Brain Injury Research Center, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
- Department of Physiology, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
- Department of Neurosurgery, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America
| |
Collapse
|
159
|
Abstract
The amyloid hypothesis for Alzheimer's disease (AD) posits a neuron-centric, linear cascade initiated by Aβ and leading to dementia. This direct causality is incompatible with clinical observations. We review evidence supporting a long, complex cellular phase consisting of feedback and feedforward responses of astrocytes, microglia, and vasculature. The field must incorporate this holistic view and take advantage of advances in single-cell approaches to resolve the critical junctures at which perturbations initially amenable to compensatory feedback transform into irreversible, progressive neurodegeneration.
Collapse
Affiliation(s)
- Bart De Strooper
- VIB Center for the Biology of Disease, VIB-Leuven, 3000 Leuven, Belgium; Center for Human Genetics, Universitaire Ziekenhuizen and LIND, KU Leuven, 3000 Leuven, Belgium; Institute of Neurology, University College London, Queen Square, WC1N 3BG London, UK.
| | - Eric Karran
- Center for Human Genetics, Universitaire Ziekenhuizen and LIND, KU Leuven, 3000 Leuven, Belgium; Institute of Neurology, University College London, Queen Square, WC1N 3BG London, UK; Alzheimer Research UK, Cambridge, CB21 6AD, UK
| |
Collapse
|
160
|
Retinal Macroglial Responses in Health and Disease. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2954721. [PMID: 27294114 PMCID: PMC4887628 DOI: 10.1155/2016/2954721] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/14/2016] [Indexed: 12/20/2022]
Abstract
Due to their permanent and close proximity to neurons, glial cells perform essential tasks for the normal physiology of the retina. Astrocytes and Müller cells (retinal macroglia) provide physical support to neurons and supplement them with several metabolites and growth factors. Macroglia are involved in maintaining the homeostasis of extracellular ions and neurotransmitters, are essential for information processing in neural circuits, participate in retinal glucose metabolism and in removing metabolic waste products, regulate local blood flow, induce the blood-retinal barrier (BRB), play fundamental roles in local immune response, and protect neurons from oxidative damage. In response to polyetiological insults, glia cells react with a process called reactive gliosis, seeking to maintain retinal homeostasis. When malfunctioning, macroglial cells can become primary pathogenic elements. A reactive gliosis has been described in different retinal pathologies, including age-related macular degeneration (AMD), diabetes, glaucoma, retinal detachment, or retinitis pigmentosa. A better understanding of the dual, neuroprotective, or cytotoxic effect of macroglial involvement in retinal pathologies would help in treating the physiopathology of these diseases. The extensive participation of the macroglia in retinal diseases points to these cells as innovative targets for new drug therapies.
Collapse
|
161
|
Astrocytes in physiological aging and Alzheimer’s disease. Neuroscience 2016; 323:170-82. [DOI: 10.1016/j.neuroscience.2015.01.007] [Citation(s) in RCA: 266] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/02/2015] [Accepted: 01/06/2015] [Indexed: 12/20/2022]
|
162
|
Norden DM, Trojanowski PJ, Walker FR, Godbout JP. Insensitivity of astrocytes to interleukin 10 signaling following peripheral immune challenge results in prolonged microglial activation in the aged brain. Neurobiol Aging 2016; 44:22-41. [PMID: 27318131 DOI: 10.1016/j.neurobiolaging.2016.04.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/18/2016] [Accepted: 04/19/2016] [Indexed: 12/21/2022]
Abstract
Immune-activated microglia from aged mice produce exaggerated levels of cytokines. Despite high levels of microglial interleukin (IL)-10 in the aged brain, neuroinflammation was prolonged and associated with depressive-like deficits. Because astrocytes respond to IL-10 and, in turn, attenuate microglial activation, we investigated if astrocyte-mediated resolution of microglial activation was impaired with age. Here, aged astrocytes had a dysfunctional profile with higher glial fibrillary acidic protein, lower glutamate transporter expression, and significant cytoskeletal re-arrangement. Moreover, aged astrocytes had reduced expression of growth factors and IL-10 receptor-1 (IL-10R1). After in vivo lipopolysaccharide immune challenge, aged astrocytes had a molecular signature associated with reduced responsiveness to IL-10. This IL-10 insensitivity of aged astrocytes resulted in a failure to induce IL-10R1 and transforming growth factor β and resolve microglial activation. In addition, adult astrocytes reduced microglial activation when co-cultured ex vivo, whereas aged astrocytes did not. Consistent with the aging studies, IL-10R(KO) astrocytes did not augment transforming growth factor β after immune challenge and failed to resolve microglial activation. Collectively, a major cytokine-regulatory loop between activated microglia and astrocytes is impaired in the aged brain.
Collapse
Affiliation(s)
- Diana M Norden
- Department of Neuroscience, The Ohio State University, Columbus, OH, USA
| | | | - Frederick R Walker
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, South Wales, Australia
| | - Jonathan P Godbout
- Department of Neuroscience, The Ohio State University, Columbus, OH, USA; Center for Brain and Spinal Cord Repair, The Ohio State University, Columbus, OH, USA; Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA.
| |
Collapse
|
163
|
Role of transient receptor potential ankyrin 1 channels in Alzheimer's disease. J Neuroinflammation 2016; 13:92. [PMID: 27121378 PMCID: PMC4847235 DOI: 10.1186/s12974-016-0557-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/19/2016] [Indexed: 12/14/2022] Open
Abstract
Background Transient receptor potential ankyrin 1 (TRPA1) channel plays an important role in pain and inflammation. However, little is known about the significance of the TRPA1 channel in the pathophysiology of Alzheimer’s disease (AD). Methods Wild-type (WT), TRPA1−/−, amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic (APP/PS1 Tg) mice, the mouse model of AD, and APP/PS1 Tg/TRPA1−/− mice were used to examine the role of TRPA1 in pathogenesis of AD. Western blot was used for protein expression; immunohistochemistry was used for histological examination. The mouse behaviors were evaluated by locomotion, nesting building, Y-maze and Morris water maze tests; levels of interleukin (IL)-1β, IL-4, IL-6 and IL-10 and the activities of protein phosphatase 2B (PP2B), NF-κB and nuclear factor of activated T cells (NFAT) were measured by conventional assay kits; Fluo-8 NW calcium (Ca2+) assay kit was used for the measurement of intracellular Ca2+ level in primary astrocytes and HEK293 cells. Results The protein expression of TRPA1 channels was higher in brains, mainly astrocytes of the hippocampus, from APP/PS1 Tg mice than WT mice. Ablation of TRPA1-channel function in APP/PS1 Tg mice alleviated behavioral dysfunction, Aβ plaque deposition and pro-inflammatory cytokine production but increased astrogliosis in brain lesions. TRPA1 channels were activated and Ca2+ influx was elicited in both astrocytes and TRPA1-transfected HEK293 cells treated with fibrilized Aβ1–42; these were abrogated by pharmacological inhibition of TRPA1 channel activity, disruption of TRPA1 channel function or removal of extracellular Ca2+. Inhibition of TRPA1 channel activity exacerbated Aβ1–42–induced astrogliosis but inhibited Aβ1–42–increased PP2B activation, the production of pro-inflammatory cytokines and activities of transcriptional factors NF-κB and NFAT in astrocytes and in APP/PS1 Tg mice. Pharmacological inhibition of PP2B activity diminished the fibrilized Aβ1–42–induced production of pro-inflammatory cytokines, activation of NF-κB and NFAT and astrogliosis in astrocytes. Conclusions TRPA1 − Ca2+ − PP2B signaling may play a crucial role in regulating astrocyte-derived inflammation and pathogenesis of AD. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0557-z) contains supplementary material, which is available to authorized users.
Collapse
|
164
|
Vitamin D interacts with Esr1 and Igf1 to regulate molecular pathways relevant to Alzheimer's disease. Mol Neurodegener 2016; 11:22. [PMID: 26932723 PMCID: PMC4774101 DOI: 10.1186/s13024-016-0087-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 02/23/2016] [Indexed: 01/05/2023] Open
Abstract
Background Increasing evidence suggests a potential therapeutic benefit of vitamin D supplementation against Alzheimer’s disease (AD). Although studies have shown improvements in cognitive performance and decreases in markers of the pathology after chronic treatment, the mechanisms by which vitamin D acts on brain cells are multiple and remain to be thoroughly studied. We analyzed the molecular changes observed after 5 months of vitamin D3 supplementation in the brains of transgenic 5xFAD (Tg) mice, a recognized mouse model of AD, and their wild type (Wt) littermates. We first performed a kinematic behavioural examination at 4, 6 and 8 months of age (M4, M6 and M8) followed by a histologic assessment of AD markers. We then performed a comparative transcriptomic analysis of mRNA regulation in the neocortex and hippocampus of 9 months old (M9) female mice. Results Transcriptomic analysis of the hippocampus and neocortex of both Wt and Tg mice at M9, following 5 months of vitamin D3 treatment, reveals a large panel of dysregulated pathways related to i) immune and inflammatory response, ii) neurotransmitter activity, iii) endothelial and vascular processes and iv) hormonal alterations. The differentially expressed genes are not all direct targets of the vitamin D-VDR pathway and it appears that vitamin D action engages in the crosstalk with estrogen and insulin signaling. The misexpression of the large number of genes observed in this study translates into improved learning and memory performance and a decrease in amyloid plaques and astrogliosis in Tg animals. Conclusions This study underlies the multiplicity of action of this potent neurosteroid in an aging and AD-like brain. The classical and non-classical actions of vitamin D3 can act in an additive and possibly synergistic manner to induce neuroprotective activities in a context-specific way. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0087-2) contains supplementary material, which is available to authorized users.
Collapse
|
165
|
Astrocytes: a central element in neurological diseases. Acta Neuropathol 2016; 131:323-45. [PMID: 26671410 DOI: 10.1007/s00401-015-1513-1] [Citation(s) in RCA: 535] [Impact Index Per Article: 66.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/28/2015] [Accepted: 11/21/2015] [Indexed: 12/18/2022]
Abstract
The neurone-centred view of the past disregarded or downplayed the role of astroglia as a primary component in the pathogenesis of neurological diseases. As this concept is changing, so is also the perceived role of astrocytes in the healthy and diseased brain and spinal cord. We have started to unravel the different signalling mechanisms that trigger specific molecular, morphological and functional changes in reactive astrocytes that are critical for repairing tissue and maintaining function in CNS pathologies, such as neurotrauma, stroke, or neurodegenerative diseases. An increasing body of evidence shows that the effects of astrogliosis on the neural tissue and its functions are not uniform or stereotypic, but vary in a context-specific manner from astrogliosis being an adaptive beneficial response under some circumstances to a maladaptive and deleterious process in another context. There is a growing support for the concept of astrocytopathies in which the disruption of normal astrocyte functions, astrodegeneration or dysfunctional/maladaptive astrogliosis are the primary cause or the main factor in neurological dysfunction and disease. This review describes the multiple roles of astrocytes in the healthy CNS, discusses the diversity of astroglial responses in neurological disorders and argues that targeting astrocytes may represent an effective therapeutic strategy for Alexander disease, neurotrauma, stroke, epilepsy and Alzheimer's disease as well as other neurodegenerative diseases.
Collapse
|
166
|
Reactive gliosis in the pathogenesis of CNS diseases. Biochim Biophys Acta Mol Basis Dis 2016; 1862:483-91. [DOI: 10.1016/j.bbadis.2015.11.014] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/19/2015] [Accepted: 11/30/2015] [Indexed: 01/11/2023]
|
167
|
Pardo L, Schlüter A, Valor LM, Barco A, Giralt M, Golbano A, Hidalgo J, Jia P, Zhao Z, Jové M, Portero-Otin M, Ruiz M, Giménez-Llort L, Masgrau R, Pujol A, Galea E. Targeted activation of CREB in reactive astrocytes is neuroprotective in focal acute cortical injury. Glia 2016; 64:853-74. [PMID: 26880229 DOI: 10.1002/glia.22969] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 01/07/2016] [Accepted: 01/08/2016] [Indexed: 01/07/2023]
Abstract
The clinical challenge in acute injury as in traumatic brain injury (TBI) is to halt the delayed neuronal loss that occurs hours and days after the insult. Here we report that the activation of CREB-dependent transcription in reactive astrocytes prevents secondary injury in cerebral cortex after experimental TBI. The study was performed in a novel bitransgenic mouse in which a constitutively active CREB, VP16-CREB, was targeted to astrocytes with the Tet-Off system. Using histochemistry, qPCR, and gene profiling we found less neuronal death and damage, reduced macrophage infiltration, preserved mitochondria, and rescued expression of genes related to mitochondrial metabolism in bitransgenic mice as compared to wild type littermates. Finally, with meta-analyses using publicly available databases we identified a core set of VP16-CREB candidate target genes that may account for the neuroprotective effect. Enhancing CREB activity in astrocytes thus emerges as a novel avenue in acute brain post-injury therapeutics.
Collapse
Affiliation(s)
- Luis Pardo
- Institut De Neurociències and Unitat De Bioquímica, Facultat De Medicina, Universitat Autònoma De Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Agatha Schlüter
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, L'hospitalet De Llobregat, Barcelona, 08907, Spain
| | - Luis M Valor
- Instituto De Neurociencias De Alicante, Universidad Miguel Hernández/Consejo Superior De Investigaciones Científicas, Sant Joan D'alacant, Alicante, 03550, Spain
| | - Angel Barco
- Instituto De Neurociencias De Alicante, Universidad Miguel Hernández/Consejo Superior De Investigaciones Científicas, Sant Joan D'alacant, Alicante, 03550, Spain
| | - Mercedes Giralt
- Institut De Neurociències and Department of Cellular Biology, Physiology and Immunology, Faculty of Biosciences, Universitat Autònoma, Barcelona, 08193, Spain
| | - Arantxa Golbano
- Institut De Neurociències and Unitat De Bioquímica, Facultat De Medicina, Universitat Autònoma De Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Juan Hidalgo
- Institut De Neurociències and Department of Cellular Biology, Physiology and Immunology, Faculty of Biosciences, Universitat Autònoma, Barcelona, 08193, Spain
| | - Peilin Jia
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee.,Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Zhongming Zhao
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee.,Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Mariona Jové
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, 25198, Spain
| | - Manuel Portero-Otin
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, 25198, Spain
| | - Montserrat Ruiz
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, L'hospitalet De Llobregat, Barcelona, 08907, Spain
| | - Lydia Giménez-Llort
- Institut De Neurociènces and Department of Psychiatry and Forensic Medicine, School of Medicine, Universitat Autònoma De Barcelona, Bellaterra, 08193, Spain
| | - Roser Masgrau
- Institut De Neurociències and Unitat De Bioquímica, Facultat De Medicina, Universitat Autònoma De Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, L'hospitalet De Llobregat, Barcelona, 08907, Spain.,Institució Catalana De Recerca I Estudis Avançats (ICREA), Barcelona, Spain
| | - Elena Galea
- Institut De Neurociències and Unitat De Bioquímica, Facultat De Medicina, Universitat Autònoma De Barcelona, Bellaterra, Barcelona, 08193, Spain.,Institució Catalana De Recerca I Estudis Avançats (ICREA), Barcelona, Spain
| |
Collapse
|
168
|
Yamazaki Y, Baker DJ, Tachibana M, Liu CC, van Deursen JM, Brott TG, Bu G, Kanekiyo T. Vascular Cell Senescence Contributes to Blood-Brain Barrier Breakdown. Stroke 2016; 47:1068-77. [PMID: 26883501 DOI: 10.1161/strokeaha.115.010835] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 01/26/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND PURPOSE Age-related changes in the cerebrovasculature, including blood-brain barrier (BBB) disruption, are emerging as potential risks for diverse neurological conditions. Because the accumulation of senescent cells in tissues is increasingly recognized as a critical step leading to age-related organ dysfunction, we evaluated whether senescent vascular cells are associated with compromised BBB integrity. METHODS Effects of vascular cell senescence on tight junction and barrier integrity were studied using an in vitro BBB model, composed of endothelial cells, pericytes, and astrocytes. In addition, tight junction coverage in microvessels and BBB integrity in BubR1 hypomorphic (BubR1(H/H)) mice, which display senescence cell-dependent phenotypes, were examined. RESULTS When an in vitro BBB model was constructed with senescent endothelial cells and pericytes, tight junction structure and barrier integrity (evaluated by transendothelial electric resistance and tracer efflux assay using sodium fluorescein and Evans blue-albumin were significantly impaired. Endothelial cells and pericytes from BubR1(H/H) mice had increased senescent-associated β-galactosidase activity and p16(INK4a) expression, demonstrating an exacerbation of senescence. The coverage by tight junction proteins in the cortical microvessels were reduced in BubR1(H/H) mice, consistent with a compromised BBB integrity from permeability assays. Importantly, the coverage of microvessels by end-feet of aquaporin 4-immunoreactive astrocytes was not altered in the cortex of the BubR1(H/H) mice. CONCLUSIONS Our results indicate that accumulation of senescent vascular cells is associated with compromised BBB integrity, providing insights into the mechanism of BBB disruption related to biological aging.
Collapse
Affiliation(s)
- Yu Yamazaki
- From the Departments of Neuroscience (Y.Y., M.T., C-C.L., G.B., T.K.) and Neurology (T.G.B.), Mayo Clinic, Jacksonville, FL; and Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (D.J.B., J.M.v.D.)
| | - Darren J Baker
- From the Departments of Neuroscience (Y.Y., M.T., C-C.L., G.B., T.K.) and Neurology (T.G.B.), Mayo Clinic, Jacksonville, FL; and Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (D.J.B., J.M.v.D.)
| | - Masaya Tachibana
- From the Departments of Neuroscience (Y.Y., M.T., C-C.L., G.B., T.K.) and Neurology (T.G.B.), Mayo Clinic, Jacksonville, FL; and Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (D.J.B., J.M.v.D.)
| | - Chia-Chen Liu
- From the Departments of Neuroscience (Y.Y., M.T., C-C.L., G.B., T.K.) and Neurology (T.G.B.), Mayo Clinic, Jacksonville, FL; and Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (D.J.B., J.M.v.D.)
| | - Jan M van Deursen
- From the Departments of Neuroscience (Y.Y., M.T., C-C.L., G.B., T.K.) and Neurology (T.G.B.), Mayo Clinic, Jacksonville, FL; and Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (D.J.B., J.M.v.D.)
| | - Thomas G Brott
- From the Departments of Neuroscience (Y.Y., M.T., C-C.L., G.B., T.K.) and Neurology (T.G.B.), Mayo Clinic, Jacksonville, FL; and Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (D.J.B., J.M.v.D.)
| | - Guojun Bu
- From the Departments of Neuroscience (Y.Y., M.T., C-C.L., G.B., T.K.) and Neurology (T.G.B.), Mayo Clinic, Jacksonville, FL; and Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (D.J.B., J.M.v.D.)
| | - Takahisa Kanekiyo
- From the Departments of Neuroscience (Y.Y., M.T., C-C.L., G.B., T.K.) and Neurology (T.G.B.), Mayo Clinic, Jacksonville, FL; and Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN (D.J.B., J.M.v.D.).
| |
Collapse
|
169
|
Astroglia dynamics in ageing and Alzheimer's disease. Curr Opin Pharmacol 2016; 26:74-9. [DOI: 10.1016/j.coph.2015.09.011] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 09/27/2015] [Indexed: 12/19/2022]
|
170
|
Astrogliosis: An integral player in the pathogenesis of Alzheimer's disease. Prog Neurobiol 2016; 144:121-41. [PMID: 26797041 DOI: 10.1016/j.pneurobio.2016.01.001] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 11/10/2015] [Accepted: 01/10/2016] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease is the main cause of dementia in the elderly and begins with a subtle decline in episodic memory followed by a more general decline in overall cognitive abilities. Though the exact trigger for this cascade of events remains unknown the presence of the misfolded amyloid-beta protein triggers reactive gliosis, a prominent neuropathological feature in the brains of Alzheimer's patients. The cytoskeletal and morphological changes of astrogliosis are its evident features, while changes in oxidative stress defense, cholesterol metabolism, and gene transcription programs are less manifest. However, these latter molecular changes may underlie a disruption in homeostatic regulation that keeps the brain environment balanced. Astrocytes in Alzheimer's disease show changes in glutamate and GABA signaling and recycling, potassium buffering, and in cholinergic, purinergic, and calcium signaling. Ultimately the dysregulation of homeostasis maintained by astrocytes can have grave consequences for the stability of microcircuits within key brain regions. Specifically, altered inhibition influenced by astrocytes can lead to local circuit imbalance with farther reaching consequences for the functioning of larger neuronal networks. Healthy astrocytes have a role in maintaining and modulating normal neuronal communication, synaptic physiology and energy metabolism, astrogliosis interferes with these functions. This review considers the molecular and functional changes occurring during astrogliosis in Alzheimer's disease, and proposes that astrocytes are key players in the development of dementia.
Collapse
|
171
|
Zhang Q, Wu HH, Wang Y, Gu GJ, Zhang W, Xia R. Neural stem cell transplantation decreases neuroinflammation in a transgenic mouse model of Alzheimer's disease. J Neurochem 2015; 136:815-825. [PMID: 26525612 DOI: 10.1111/jnc.13413] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 10/17/2015] [Accepted: 10/20/2015] [Indexed: 12/13/2022]
Abstract
Inflammatory processes are considered to play an important role in the progression of neurodegenerative changes in Alzheimer's disease (AD). A number of studies have reported that inflammatory processes are highly correlated with cognitive deficits in AD-like mice. Transplantation of neural stem cells (NSCs) has been considered as a potential new therapy for the treatment of AD because of its effects in improving cognitive ability. However, NSCs have not been evaluated for their protective effects against inflammatory changes in AD. Here, we injected NSCs into amyloid precursor protein (APP)/PS1 transgenic mice to analyse cognitive function and to measure glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule-1 (Iba-1) and toll-like receptors 4(TLR4) activation. We also quantified TLR-4 pathway-related agents, Aβ concentration and the levels of proinflammatory mediators. Our results showed that in NSC-injected APP/PS1 mice, activation of GFAP, Iba-1, TLR4 and TLR4 pathway-related agents (MyD88, TRIF, P38 MAPK and NF-κB P65) were significantly decreased with decreased expression of proinflammatory mediators (IL-1, IL-6, TNF-α and PGE2). These changes were associated with the amelioration of cognitive deficits, but no difference was found in Aβ concentration. Our results provide novel evidence that NSC transplantation in APP/PS1 mice significantly improved cognitive deficits and was accompanied by the attenuation of inflammatory injury via suppression of glial and TLR4-mediated inflammatory pathway activation. Our data indicate that these pathways may potentially be important therapeutic targets to prevent or delay AD. This study investigated the neuroprotective effect of neural stem cell (NSC) transplantation against Alzheimer's disease (AD) inflammation. We found that NSC treatment in APP/PS1 mice significantly improved cognitive deficits and was accompanied by the attenuation of inflammatory injury via suppression of glial and toll-like receptor 4 (TLR4) activation and its downstream signalling pathways. Our findings indicate that these pathways may be potentially important therapeutic targets to prevent or delay AD.
Collapse
Affiliation(s)
- Qi Zhang
- Department of Blood Transfusion, Huashan Hospital, Fudan University, Shanghai, China
| | - Hua-Hui Wu
- Harbin Hospital of Traditional Chinese Medicine, Harbin, Heilongjiang, China
| | - Yuan Wang
- Department of Blood Transfusion, Huashan Hospital, Fudan University, Shanghai, China
| | - Guo-Jun Gu
- Department of Medical Imaging, Tongji Hospital, Medical School of Tongji University, Shanghai, China
| | - Wei Zhang
- Department of Medical Imaging, Renji Hospital, Medical School of Jiaotong University, Shanghai, China
| | - Rong Xia
- Department of Blood Transfusion, Huashan Hospital, Fudan University, Shanghai, China
| |
Collapse
|
172
|
Serrano-Pozo A, Betensky RA, Frosch MP, Hyman BT. Plaque-Associated Local Toxicity Increases over the Clinical Course of Alzheimer Disease. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 186:375-84. [PMID: 26687817 DOI: 10.1016/j.ajpath.2015.10.010] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/01/2015] [Accepted: 10/07/2015] [Indexed: 11/19/2022]
Abstract
Amyloid (senile) plaques, one of the two pathologic hallmarks of Alzheimer disease (AD), are associated with dystrophic neurites and glial responses, both astrocytic and microglial. Although plaque burden remains relatively stable through the clinical course of AD, whether these features of local plaque toxicity continue to worsen over the course of the disease is unclear. We performed an unbiased plaque-centered quantification of SMI312(+) dystrophic neurites, GFAP(+) reactive astrocytes, and IBA1(+) and CD68(+) activated microglia in randomly selected dense-core (Thioflavin-S(+)) plaques from the temporal neocortex of 40 AD subjects with a symptom duration ranging from 4 to 20 years, and nine nondemented control subjects with dense-core plaques. Dystrophic neurites (Kendall τ = 0.34, P = 0.001), reactive astrocytes (Kendall τ = 0.30, P = 0.003), and CD68(+) (Kendall τ = 0.48, P < 0.0001), but not IBA1 microglia (Kendall τ = 0.045, P = 0.655), exhibited a significant positive correlation with symptom duration. When excluding control subjects, only the positive association between CD68(+) microglia and symptom duration remained significant (Kendall τ = 0.39, P = 0.0003). The presence of the APOEε4 allele did not affect these results. We conclude that plaques exert an increasing toxicity in the surrounding neuropil over the clinical course of AD, thereby potentially contributing to cognitive decline.
Collapse
Affiliation(s)
- Alberto Serrano-Pozo
- Massachusetts Alzheimer Disease Research Center, Massachusetts General Hospital, Charlestown, Massachusetts; Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts; Department of Neurology, University of Iowa Hospitals & Clinics, Iowa City, Iowa
| | - Rebecca A Betensky
- Massachusetts Alzheimer Disease Research Center, Massachusetts General Hospital, Charlestown, Massachusetts; Biostatistics Center, Massachusetts General Hospital, Boston, Massachusetts; Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Matthew P Frosch
- Massachusetts Alzheimer Disease Research Center, Massachusetts General Hospital, Charlestown, Massachusetts; C. S. Kubik Laboratory for Neuropathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Bradley T Hyman
- Massachusetts Alzheimer Disease Research Center, Massachusetts General Hospital, Charlestown, Massachusetts; Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts.
| |
Collapse
|
173
|
Topological analyses in APP/PS1 mice reveal that astrocytes do not migrate to amyloid-β plaques. Proc Natl Acad Sci U S A 2015; 112:15556-61. [PMID: 26644572 DOI: 10.1073/pnas.1516779112] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Although the clustering of GFAP immunopositive astrocytes around amyloid-β plaques in Alzheimer's disease has led to the widespread assumption that plaques attract astrocytes, recent studies suggest that astrocytes stay put in injury. Here we reexamine astrocyte migration to plaques, using quantitative spatial analysis and computer modeling to investigate the topology of astrocytes in 3D images obtained by two-photon microscopy of living APP/PS1 mice and WT littermates. In WT mice, cortical astrocyte topology fits a model in which a liquid of hard spheres exclude each other in a confined space. Plaques do not disturb this arrangement except at very large plaque loads, but, locally, cause subtle outward shifts of the astrocytes located in three tiers around plaques. These data suggest that astrocytes respond to plaque-induced neuropil injury primarily by changing phenotype, and hence function, rather than location.
Collapse
|
174
|
Xie H, Xiao Z, Huang J. C6 Glioma-Secreted NGF and FGF2 Regulate Neuronal APP Processing Through Up-Regulation of ADAM10 and Down-Regulation of BACE1, Respectively. J Mol Neurosci 2015; 59:334-42. [PMID: 26614345 DOI: 10.1007/s12031-015-0690-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/19/2015] [Indexed: 01/05/2023]
Abstract
Excessive accumulation of amyloid-β (Aβ) caused by cleavage of amyloid precursor protein (APP) is thought to be the primary cause of Alzheimer's disease (AD). Two key enzymes ADAM10 and BACE1 are involved in the initial cleavage of APP, resulting in the onset of two pathways, the amyloidogenic pathway and the non-amyloidogenic pathway, respectively. Altering APP metabolism towards the non-amyloidogenic pathway is thought to reduce Aβ production. It has been reported that, in vivo, exogenous neurotrophic factors make APP apt to entering the non-amyloidogenic pathway. Since astrocytes secrete a battery of neurotrophic factors, we investigated the role of astrocyte-derived factors in the dynamics of Aβ generation in neural cells. Results show that C6 glioma cell-conditioned medium (GCM), obtained from cultured astrocyte-derived C6 glioma cells, inhibit Aβ1-42 production and shift APP processing towards the non-amyloidogenic pathway in APPswe-HEK293 cells. Such effect is attributed to two key APP cleavage enzymes, ADAM10 and BACE1. Two neurotrophic factors in the GCM, nerve growth factor and fibroblast growth factor 2, are responsible for the up-regulation of ADAM10 and down-regulation of BACE1, respectively. Our findings enhance our understanding of the relationship between astrocytes and Aβ generation, indicating that stimulation of astrocytic neurotrophic factors could slow AD progression.
Collapse
Affiliation(s)
- Huiping Xie
- College of Life Sciences, Wuhan University, Room 5105, Wuhan, Hubei, 430072, People's Republic of China
| | - Zhimin Xiao
- College of Life Sciences, Wuhan University, Room 5105, Wuhan, Hubei, 430072, People's Republic of China.,Sanofi, Cambridge, MA, 02142, USA
| | - Jian Huang
- College of Life Sciences, Wuhan University, Room 5105, Wuhan, Hubei, 430072, People's Republic of China.
| |
Collapse
|
175
|
Xu Z, Xiao N, Chen Y, Huang H, Marshall C, Gao J, Cai Z, Wu T, Hu G, Xiao M. Deletion of aquaporin-4 in APP/PS1 mice exacerbates brain Aβ accumulation and memory deficits. Mol Neurodegener 2015; 10:58. [PMID: 26526066 PMCID: PMC4631089 DOI: 10.1186/s13024-015-0056-1] [Citation(s) in RCA: 298] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/29/2015] [Indexed: 12/20/2022] Open
Abstract
Background Preventing or reducing amyloid-beta (Aβ) accumulation in the brain is an important therapeutic strategy for Alzheimer’s disease (AD). Recent studies showed that the water channel aquaporin-4 (AQP4) mediates soluble Aβ clearance from the brain parenchyma along the paravascular pathway. However the direct evidence for roles of AQP4 in the pathophysiology of AD remains absent. Results Here, we reported that the deletion of AQP4 exacerbated cognitive deficits of 12-moth old APP/PS1 mice, with increases in Aβ accumulation, cerebral amyloid angiopathy and loss of synaptic protein and brain-derived neurotrophic factor in the hippocampus and cortex. Furthermore, AQP4 deficiency increased atrophy of astrocytes with significant decreases in interleukin-1 beta and nonsignficant decreases in interleukin-6 and tumor necrosis factor-alpha in hippocampal and cerebral samples. Conclusions These results suggest that AQP4 attenuates Aβ pathogenesis despite its potentially inflammatory side-effects, thus serving as a promising target for treating AD. Electronic supplementary material The online version of this article (doi:10.1186/s13024-015-0056-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Zhiqiang Xu
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Na Xiao
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Yali Chen
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Huang Huang
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Charles Marshall
- Department of Rehabilitation Sciences, University of Kentucky Center of Excellence in Rural Health, Hazard, KY, USA
| | - Junying Gao
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Zhiyou Cai
- Department of Neurology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Ting Wu
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Gang Hu
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu, 210029, China
| | - Ming Xiao
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, 140 Hanzhong Road, Nanjing, Jiangsu, 210029, China.
| |
Collapse
|
176
|
Astrocyte-mediated metaplasticity in the hippocampus: Help or hindrance? Neuroscience 2015; 309:113-24. [DOI: 10.1016/j.neuroscience.2015.08.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 08/03/2015] [Accepted: 08/17/2015] [Indexed: 12/22/2022]
|
177
|
Liu Z, Chopp M. Astrocytes, therapeutic targets for neuroprotection and neurorestoration in ischemic stroke. Prog Neurobiol 2015; 144:103-20. [PMID: 26455456 DOI: 10.1016/j.pneurobio.2015.09.008] [Citation(s) in RCA: 401] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 08/06/2015] [Accepted: 09/05/2015] [Indexed: 01/04/2023]
Abstract
Astrocytes are the most abundant cell type within the central nervous system. They play essential roles in maintaining normal brain function, as they are a critical structural and functional part of the tripartite synapses and the neurovascular unit, and communicate with neurons, oligodendrocytes and endothelial cells. After an ischemic stroke, astrocytes perform multiple functions both detrimental and beneficial, for neuronal survival during the acute phase. Aspects of the astrocytic inflammatory response to stroke may aggravate the ischemic lesion, but astrocytes also provide benefit for neuroprotection, by limiting lesion extension via anti-excitotoxicity effects and releasing neurotrophins. Similarly, during the late recovery phase after stroke, the glial scar may obstruct axonal regeneration and subsequently reduce the functional outcome; however, astrocytes also contribute to angiogenesis, neurogenesis, synaptogenesis, and axonal remodeling, and thereby promote neurological recovery. Thus, the pivotal involvement of astrocytes in normal brain function and responses to an ischemic lesion designates them as excellent therapeutic targets to improve functional outcome following stroke. In this review, we will focus on functions of astrocytes and astrocyte-mediated events during stroke and recovery. We will provide an overview of approaches on how to reduce the detrimental effects and amplify the beneficial effects of astrocytes on neuroprotection and on neurorestoration post stroke, which may lead to novel and clinically relevant therapies for stroke.
Collapse
Affiliation(s)
- Zhongwu Liu
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA.
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA; Department of Physics, Oakland University, Rochester, MI, USA
| |
Collapse
|
178
|
Tong J, Ang LC, Williams B, Furukawa Y, Fitzmaurice P, Guttman M, Boileau I, Hornykiewicz O, Kish SJ. Low levels of astroglial markers in Parkinson's disease: relationship to α-synuclein accumulation. Neurobiol Dis 2015; 82:243-253. [PMID: 26102022 PMCID: PMC4641013 DOI: 10.1016/j.nbd.2015.06.010] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 06/04/2015] [Accepted: 06/17/2015] [Indexed: 01/25/2023] Open
Abstract
Although gliosis is a normal response to brain injury, reports on the extent of astrogliosis in the degenerating substantia nigra in Parkinson's disease (PD) are conflicting. It has also been recently suggested that accumulation of nigral α-synuclein in this disorder might suppress astrocyte activation which in turn could exacerbate the degenerative process. This study examined brain protein levels (intact protein, fragments, and aggregates, if any) of astroglial markers and their relationship to α-synuclein in PD and in the positive control parkinson-plus conditions multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). Autopsied brain homogenates of patients with PD (n=10), MSA (n=11), PSP (n=11) and matched controls (n=10) were examined for the astroglial markers glial fibrillary acidic protein (GFAP), vimentin, and heat shock protein-27 (Hsp27) by quantitative immunoblotting. As expected, both MSA (putamen>substantia nigra>caudate>frontal cortex) and PSP (substantia nigra>caudate>putamen, frontal cortex) showed widespread but regionally specific pattern of increased immunoreactivity of the markers, in particular for the partially proteolyzed fragments (all three) and aggregates (GFAP). In contrast, immunoreactivity of the three markers was largely normal in PD in brain regions examined with the exception of trends for variably increased levels of cleaved vimentin in substantia nigra and frontal cortex. In patients with PD, GFAP levels in the substantia nigra correlated inversely with α-synuclein accumulation whereas the opposite was true for MSA. Our biochemical findings of generally normal protein levels of astroglial markers in substantia nigra of PD, and negative correlation with α-synuclein concentration, are consistent with some recent neuropathology reports of mild astroglial response and with the speculation that astrogliosis might be suppressed in this disorder by excessive α-synuclein accumulation. Should astrogliosis protect, to some extent, the degenerating substantia nigra from damage, therapeutics aimed at normalization of astrocyte reaction in PD could be helpful.
Collapse
Affiliation(s)
- Junchao Tong
- Human Brain Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Addiction Imaging Research Group, Campbell Family Mental Health Research Institute, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.
| | - Lee-Cyn Ang
- Division of Neuropathology, London Health Science Centre, University of Western Ontario, London, Ontario, Canada
| | - Belinda Williams
- Addiction Imaging Research Group, Campbell Family Mental Health Research Institute, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Yoshiaki Furukawa
- Department of Neurology, Juntendo Tokyo Koto Geriatric Medical Center, and Faculty of Medicine, University & Post Graduate University of Juntendo, Tokyo, Japan
| | | | - Mark Guttman
- Centre for Movement Disorders, Toronto, Ontario, Canada
| | - Isabelle Boileau
- Addiction Imaging Research Group, Campbell Family Mental Health Research Institute, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Oleh Hornykiewicz
- Center for Brain Research, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria
| | - Stephen J Kish
- Human Brain Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| |
Collapse
|
179
|
Wang TZ, Sun A, Wang N, Cui ZK, Chen SL, Sha ZX. Establishment and characterization of an astroglial cell line derived from the brain of half-smooth tongue sole (Cynoglossus semilaevis). DONG WU XUE YAN JIU = ZOOLOGICAL RESEARCH 2015; 36:305-10. [PMID: 26452695 DOI: 10.13918/j.issn.2095-8137.2015.5.305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
An astroglial cell line was established from the brain of half smooth tongue sole (Cynoglossus semilaevis) and was designated as CSAC. CSAC shows the morphological homogeneity of epithelial cells. The cell identity was tested by the presence of glial fibrillary acidic protein (GFAP), which was revealed by RT-PCR and immunofluorescence. The cell line was optimally maintained at 24 °C in minimum essential medium supplemented with HEPES, antibiotics, 20% fetal bovine serum, 2-Mercaptoethanol (2-Me) and basic fibroblast growth factor. Chromosome analysis revealed that the CSAC cells maintained a normal diploid chromosome number (2n=42). The fluorescent signals were observed in CSAC after the cells were transfected with green fluorescent protein (GFP) reporter plasmids. The CSAC cell line may serve as a valuable tool for studies on the potential functions of fish astroglial cells.
Collapse
Affiliation(s)
- Tian-Zi Wang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Ai Sun
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, National Lab for Ocean Science and Technology, 266003, China
| | - Na Wang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, National Lab for Ocean Science and Technology, 266003, China
| | - Zhong-Kai Cui
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Song-Lin Chen
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071,
| | - Zhen-Xia Sha
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China.
| |
Collapse
|
180
|
Wunderlich KA, Tanimoto N, Grosche A, Zrenner E, Pekny M, Reichenbach A, Seeliger MW, Pannicke T, Perez MT. Retinal functional alterations in mice lacking intermediate filament proteins glial fibrillary acidic protein and vimentin. FASEB J 2015; 29:4815-28. [PMID: 26251181 DOI: 10.1096/fj.15-272963] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/27/2015] [Indexed: 01/02/2023]
Abstract
Vimentin (Vim) and glial fibrillary acidic protein (GFAP) are important components of the intermediate filament (IF) (or nanofilament) system of astroglial cells. We conducted full-field electroretinogram (ERG) recordings and found that whereas photoreceptor responses (a-wave) were normal in uninjured GFAP(-/-)Vim(-/-) mice, b-wave amplitudes were increased. Moreover, we found that Kir (inward rectifier K(+)) channel protein expression was reduced in the retinas of GFAP(-/-)Vim(-/-) mice and that Kir-mediated current amplitudes were lower in Müller glial cells isolated from these mice. Studies have shown that the IF system, in addition, is involved in the retinal response to injury and that attenuated Müller cell reactivity and reduced photoreceptor cell loss are observed in IF-deficient mice after experimental retinal detachment. We investigated whether the lack of IF proteins would affect cell survival in a retinal ischemia-reperfusion model. We found that although cell loss was induced in both genotypes, the number of surviving cells in the inner retina was lower in IF-deficient mice. Our findings thus show that the inability to produce GFAP and Vim affects normal retinal physiology and that the effect of IF deficiency on retinal cell survival differs, depending on the underlying pathologic condition.
Collapse
Affiliation(s)
- Kirsten A Wunderlich
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Naoyuki Tanimoto
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Antje Grosche
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Eberhart Zrenner
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Milos Pekny
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Andreas Reichenbach
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Mathias W Seeliger
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Pannicke
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Maria-Thereza Perez
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| |
Collapse
|
181
|
Illes P, Verkhratsky A. Purinergic neurone-glia signalling in cognitive-related pathologies. Neuropharmacology 2015; 104:62-75. [PMID: 26256423 DOI: 10.1016/j.neuropharm.2015.08.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/19/2015] [Accepted: 08/03/2015] [Indexed: 12/31/2022]
Abstract
Neuroglia, represented by astrocytes, oligodendrocytes, NG glia and microglia are homeostatic, myelinating and defensive cells of the brain. Neuroglial cells express various combinations of purinoceptors, which contribute to multiple intercellular signalling pathways in the healthy and diseased nervous system. Neurological diseases are invariably associated with profound neuroglial remodelling, which is manifest by reactive gliosis, pathological remodelling and functional atrophy of various types of glial cells. Gliopathology is disease and region specific and produces multiple glial phenotypes that may be neuroprotective or neurotoxic. In this review we summarise recent knowledge on the role of glial purinergic signalling in cognitive-related neurological diseases. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
Collapse
Affiliation(s)
- Peter Illes
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany.
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain; University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia.
| |
Collapse
|
182
|
Ben Haim L, Carrillo-de Sauvage MA, Ceyzériat K, Escartin C. Elusive roles for reactive astrocytes in neurodegenerative diseases. Front Cell Neurosci 2015; 9:278. [PMID: 26283915 PMCID: PMC4522610 DOI: 10.3389/fncel.2015.00278] [Citation(s) in RCA: 292] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/06/2015] [Indexed: 12/21/2022] Open
Abstract
Astrocytes play crucial roles in the brain and are involved in the neuroinflammatory response. They become reactive in response to virtually all pathological situations in the brain such as axotomy, ischemia, infection, and neurodegenerative diseases (ND). Astrocyte reactivity was originally characterized by morphological changes (hypertrophy, remodeling of processes) and the overexpression of the intermediate filament glial fibrillary acidic protein (GFAP). However, it is unclear how the normal supportive functions of astrocytes are altered by their reactive state. In ND, in which neuronal dysfunction and astrocyte reactivity take place over several years or decades, the issue is even more complex and highly debated, with several conflicting reports published recently. In this review, we discuss studies addressing the contribution of reactive astrocytes to ND. We describe the molecular triggers leading to astrocyte reactivity during ND, examine how some key astrocyte functions may be enhanced or altered during the disease process, and discuss how astrocyte reactivity may globally affect ND progression. Finally we will consider the anticipated developments in this important field. With this review, we aim to show that the detailed study of reactive astrocytes may open new perspectives for ND.
Collapse
Affiliation(s)
- Lucile Ben Haim
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département des Sciences du Vivant, Institut d'Imagerie Biomédicale, MIRCen Fontenay-aux-Roses, France ; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, UMR 9199 Fontenay-aux-Roses, France
| | - Maria-Angeles Carrillo-de Sauvage
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département des Sciences du Vivant, Institut d'Imagerie Biomédicale, MIRCen Fontenay-aux-Roses, France ; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, UMR 9199 Fontenay-aux-Roses, France
| | - Kelly Ceyzériat
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département des Sciences du Vivant, Institut d'Imagerie Biomédicale, MIRCen Fontenay-aux-Roses, France ; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, UMR 9199 Fontenay-aux-Roses, France
| | - Carole Escartin
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département des Sciences du Vivant, Institut d'Imagerie Biomédicale, MIRCen Fontenay-aux-Roses, France ; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, UMR 9199 Fontenay-aux-Roses, France
| |
Collapse
|
183
|
Ghoneim FM, Khalaf HA, Elsamanoudy AZ, Abo El-khair SM, Helaly AMN, Mahmoud EHM, Elshafey SH. Protective effect of chronic caffeine intake on gene expression of brain derived neurotrophic factor signaling and the immunoreactivity of glial fibrillary acidic protein and Ki-67 in Alzheimer's disease. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:7710-7728. [PMID: 26339337 PMCID: PMC4555665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 06/26/2015] [Indexed: 06/05/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder with progressive degeneration of the hippocampal and cortical neurons. This study was designed to demonstrate the protective effect of caffeine on gene expression of brain derived neurotrophic factor (BDNF) and its receptor neural receptor protein-tyrosine kinase-β (TrkB) as well as glial fibrillary acidic protein (GFAP) and Ki-67 immunoreactivity in Aluminum chloride (AlCl3) induced animal model of AD. Fifty adult rats included in this study were classified into 5 group (10 rats each); negative and positive control groups (I&II), AD model group (III), group treated with caffeine from the start of AD induction (IV) and group treated with caffeine two weeks before AD induction (V). Hippocampal tissue BDNF and its receptor (TrkB) gene expression by real time RT-PCR in addition to immunohistochemical study of GFAP and Ki67 immunoreactivity were performed for all rats in the study. The results of this study revealed that caffeine has protective effect through improving the histological and immunohistochemical findings induced by AlCl3 as well as BDNF and its receptor gene expression. It could be concluded from the current study, that chronic caffeine consumption in a dose of 1.5 mg/kg body weight daily has a potentially good protective effect against AD.
Collapse
Affiliation(s)
- Fatma M Ghoneim
- Department of Histology and Cell Biology, Mansoura UniversityEgypt
| | - Hanaa A Khalaf
- Department of Histology and Cell Biology, Mansoura UniversityEgypt
| | - Ayman Z Elsamanoudy
- Department of Medical Biochemistry and Molecular Biology, Mansoura UniversityEgypt
| | - Salwa M Abo El-khair
- Department of Medical Biochemistry and Molecular Biology, Mansoura UniversityEgypt
| | - Ahmed MN Helaly
- Department of Forensic Medicine and Toxicology, Mansoura UniversityEgypt
| | | | - Saad H Elshafey
- Department of Histology and Cell Biology, Mansoura UniversityEgypt
| |
Collapse
|
184
|
Abstract
Astrocytes form borders (glia limitans) that separate neural from non-neural tissue along perivascular spaces, meninges and tissue lesions in the CNS. Transgenic loss-of-function studies reveal that astrocyte borders and scars serve as functional barriers that restrict the entry of inflammatory cells into CNS parenchyma in health and disease. Astrocytes also have powerful pro-inflammatory potential. Thus, astrocytes are emerging as pivotal regulators of CNS inflammatory responses. This Review discusses evidence that astrocytes have crucial roles in attracting and restricting CNS inflammation, with important implications for diverse CNS disorders.
Collapse
Affiliation(s)
- Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| |
Collapse
|
185
|
Abstract
Astrocytes were historically classified as supporting cells; however, it is becoming increasingly clear that they actively contribute to neuronal functioning under normal and pathological conditions. As interest in the contribution of neuroinflammation to Alzheimer's disease (AD) progression has grown, manipulating glial cells has become an attractive target for future therapies. Astrocytes have largely been under-represented in studies that assess the role of glia in these processes, despite substantial evidence of astrogliosis in AD. The actual role of astrocytes in AD remains elusive, as they seem to adopt different functions dependent on disease progression and the extent of accompanying parenchymal inflammation. Astrocytes may contribute to the clearance of amyloid β-peptide (Aβ) and restrict the spread of inflammation in the brain. Conversely, they may contribute to neurodegeneration in AD by releasing neurotoxins and neglecting crucial metabolic roles. The present review summarizes current evidence on the multi-faceted functions of astrocytes in AD, highlighting the significant scope available for future therapeutic targets.
Collapse
|
186
|
Yan P, Zhu A, Liao F, Xiao Q, Kraft A, Gonzales E, Perez R, Greenberg SM, Holtzman D, Lee JM. Minocycline reduces spontaneous hemorrhage in mouse models of cerebral amyloid angiopathy. Stroke 2015; 46:1633-1640. [PMID: 25944329 DOI: 10.1161/strokeaha.115.008582] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/19/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE Cerebral amyloid angiopathy (CAA) is a common cause of recurrent intracerebral hemorrhage in the elderly. Previous studies have shown that CAA induces inflammation and expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 (gelatinases) in amyloid-laden vessels. Here, we inhibited both using minocycline in CAA mouse models to determine whether spontaneous intracerebral hemorrhage could be reduced. METHODS Tg2576 (n=16) and 5xFAD/ApoE4 knockin mice (n=16), aged 17 and 12 months, respectively, were treated with minocycline (50 mg/kg, IP) or saline every other day for 2 months. Brains were extracted and stained with X-34 (to quantify amyloid), Perls' blue (to quantify hemorrhage), and immunostained to examined β-amyloid peptide load, gliosis (glial fibrillary acidic protein [GFAP], Iba-1), and vascular markers of blood-brain barrier integrity (zonula occludins-1 [ZO-1] and collagen IV). Brain extracts were used to quantify mRNA for a variety of inflammatory genes. RESULTS Minocycline treatment significantly reduced hemorrhage frequency in the brains of Tg2576 and 5xFAD/ApoE4 mice relative to the saline-treated mice, without affecting CAA load. Gliosis (GFAP and Iba-1 immunostaining), gelatinase activity, and expression of a variety of inflammatory genes (matrix metalloproteinase-9, NOX4, CD45, S-100b, and Iba-1) were also significantly reduced. Higher levels of microvascular tight junction and basal lamina proteins were found in the brains of minocycline-treated Tg2576 mice relative to saline-treated controls. CONCLUSIONS Minocycline reduced gliosis, inflammatory gene expression, gelatinase activity, and spontaneous hemorrhage in 2 different mouse models of CAA, supporting the importance of matrix metalloproteinase-related and inflammatory pathways in intracerebral hemorrhage pathogenesis. As a Food and Drug Administration-approved drug, minocycline might be considered for clinical trials to test efficacy in preventing CAA-related intracerebral hemorrhage.
Collapse
Affiliation(s)
- Ping Yan
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Alec Zhu
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Fan Liao
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Qingli Xiao
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Andrew Kraft
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Ernie Gonzales
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Ron Perez
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Steven M Greenberg
- Philip Kistler Stroke Research Center, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - David Holtzman
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jin-Moo Lee
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| |
Collapse
|
187
|
Rodriguez-Vieitez E, Ni R, Gulyás B, Tóth M, Häggkvist J, Halldin C, Voytenko L, Marutle A, Nordberg A. Astrocytosis precedes amyloid plaque deposition in Alzheimer APPswe transgenic mouse brain: a correlative positron emission tomography and in vitro imaging study. Eur J Nucl Med Mol Imaging 2015; 42:1119-32. [PMID: 25893384 PMCID: PMC4424277 DOI: 10.1007/s00259-015-3047-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 03/12/2015] [Indexed: 01/19/2023]
Abstract
PURPOSE Pathological studies suggest that neuroinflammation is exacerbated by increased beta-amyloid (Aβ) levels in the brain early in Alzheimer's disease (AD). The time course and relationships between astrocytosis and Aβ deposition were examined using multitracer in vivo positron emission tomography (PET) imaging in an AD transgenic mouse model, followed by postmortem autoradiography and immunohistochemistry analysis. METHODS PET imaging with the amyloid plaque tracer (11)C-AZD2184 and the astroglial tracer (11)C-deuterium-L-deprenyl ((11)C-DED) was carried out in APPswe mice aged 6, 8-15 and 18-24 months (4-6 animals/group) and in wild-type (wt) mice aged 8-15 and 18-24 months (3-6 animals/group). Tracer uptake was quantified by region of interest analysis using PMOD software and a 3-D digital mouse brain atlas. Postmortem brain tissues from the same APPswe and wt mice in all age groups were analysed for Aβ deposition and astrocytosis by in vitro autoradiography using (3)H-AZD2184, (3)H-Pittsburgh compound B (PIB) and (3)H-L-deprenyl and immunostaining performed with antibodies for Aβ42 and glial fibrillary acidic protein (GFAP) in sagittal brain sections. RESULTS (11)C-AZD2184 PET retention in the cerebral cortices of APPswe mice was significantly higher at 18-24 months than in age-matched wt mice. Cortical and hippocampal (11)C-DED PET binding was significantly higher at 6 months than at 8-15 months or 18-24 months in APPswe mice, and it was also higher than at 8-15 months in wt mice. In vitro autoradiography (3)H-AZD2184 and (3)H-PIB binding confirmed the in vivo findings with (11)C-AZD2184 and demonstrated age-dependent increases in Aβ deposition in APPswe cortex and hippocampus. There were no significant differences between APPswe and wt mice in (3)H-L-deprenyl autoradiography binding across age groups. Immunohistochemical quantification demonstrated more Aβ42 deposits in the cortex and hippocampus and more GFAP(+) reactive astrocytes in the hippocampus at 18-24 months than at 6 months in APPswe mice. CONCLUSION The findings provide further in vivo evidence that astrocytosis occurs early in AD, preceding Aβ plaque deposition.
Collapse
Affiliation(s)
- Elena Rodriguez-Vieitez
- Division of Translational Alzheimer Neurobiology, Centre for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Novum 5th Floor, Blickagången 6, 141 57, Stockholm, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
188
|
The JAK/STAT3 pathway is a common inducer of astrocyte reactivity in Alzheimer's and Huntington's diseases. J Neurosci 2015; 35:2817-29. [PMID: 25673868 DOI: 10.1523/jneurosci.3516-14.2015] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Astrocyte reactivity is a hallmark of neurodegenerative diseases (ND), but its effects on disease outcomes remain highly debated. Elucidation of the signaling cascades inducing reactivity in astrocytes during ND would help characterize the function of these cells and identify novel molecular targets to modulate disease progression. The Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) pathway is associated with reactive astrocytes in models of acute injury, but it is unknown whether this pathway is directly responsible for astrocyte reactivity in progressive pathological conditions such as ND. In this study, we examined whether the JAK/STAT3 pathway promotes astrocyte reactivity in several animal models of ND. The JAK/STAT3 pathway was activated in reactive astrocytes in two transgenic mouse models of Alzheimer's disease and in a mouse and a nonhuman primate lentiviral vector-based model of Huntington's disease (HD). To determine whether this cascade was instrumental for astrocyte reactivity, we used a lentiviral vector that specifically targets astrocytes in vivo to overexpress the endogenous inhibitor of the JAK/STAT3 pathway [suppressor of cytokine signaling 3 (SOCS3)]. SOCS3 significantly inhibited this pathway in astrocytes, prevented astrocyte reactivity, and decreased microglial activation in models of both diseases. Inhibition of the JAK/STAT3 pathway within reactive astrocytes also increased the number of huntingtin aggregates, a neuropathological hallmark of HD, but did not influence neuronal death. Our data demonstrate that the JAK/STAT3 pathway is a common mediator of astrocyte reactivity that is highly conserved between disease states, species, and brain regions. This universal signaling cascade represents a potent target to study the role of reactive astrocytes in ND.
Collapse
|
189
|
Glial fibrillary acidic protein (GFAP) and the astrocyte intermediate filament system in diseases of the central nervous system. Curr Opin Cell Biol 2015; 32:121-30. [PMID: 25726916 DOI: 10.1016/j.ceb.2015.02.004] [Citation(s) in RCA: 536] [Impact Index Per Article: 59.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 02/04/2015] [Accepted: 02/09/2015] [Indexed: 01/14/2023]
Abstract
Glial fibrillary acidic protein (GFAP) is the hallmark intermediate filament (IF; also known as nanofilament) protein in astrocytes, a main type of glial cells in the central nervous system (CNS). Astrocytes have a range of control and homeostatic functions in health and disease. Astrocytes assume a reactive phenotype in acute CNS trauma, ischemia, and in neurodegenerative diseases. This coincides with an upregulation and rearrangement of the IFs, which form a highly complex system composed of GFAP (10 isoforms), vimentin, synemin, and nestin. We begin to unravel the function of the IF system of astrocytes and in this review we discuss its role as an important crisis-command center coordinating cell responses in situations connected to cellular stress, which is a central component of many neurological diseases.
Collapse
|
190
|
Kamphuis W, Kooijman L, Orre M, Stassen O, Pekny M, Hol EM. GFAP and vimentin deficiency alters gene expression in astrocytes and microglia in wild-type mice and changes the transcriptional response of reactive glia in mouse model for Alzheimer's disease. Glia 2015; 63:1036-56. [PMID: 25731615 DOI: 10.1002/glia.22800] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/14/2015] [Indexed: 11/07/2022]
Abstract
Reactive astrocytes with an increased expression of intermediate filament (IF) proteins Glial Fibrillary Acidic Protein (GFAP) and Vimentin (VIM) surround amyloid plaques in Alzheimer's disease (AD). The functional consequences of this upregulation are unclear. To identify molecular pathways coupled to IF regulation in reactive astrocytes, and to study the interaction with microglia, we examined WT and APPswe/PS1dE9 (AD) mice lacking either GFAP, or both VIM and GFAP, and determined the transcriptome of cortical astrocytes and microglia from 15- to 18-month-old mice. Genes involved in lysosomal degradation (including several cathepsins) and in inflammatory response (including Cxcl5, Tlr6, Tnf, Il1b) exhibited a higher AD-induced increase when GFAP, or VIM and GFAP, were absent. The expression of Aqp4 and Gja1 displayed the same pattern. The downregulation of neuronal support genes in astrocytes from AD mice was absent in GFAP/VIM null mice. In contrast, the absence of IFs did not affect the transcriptional alterations induced by AD in microglia, nor was the cortical plaque load altered. Visualizing astrocyte morphology in GFAP-eGFP mice showed no clear structural differences in GFAP/VIM null mice, but did show diminished interaction of astrocyte processes with plaques. Microglial proliferation increased similarly in all AD groups. In conclusion, absence of GFAP, or both GFAP and VIM, alters AD-induced changes in gene expression profile of astrocytes, showing a compensation of the decrease of neuronal support genes and a trend for a slightly higher inflammatory expression profile. However, this has no consequences for the development of plaque load, microglial proliferation, or microglial activation.
Collapse
Affiliation(s)
- Willem Kamphuis
- Astrocyte Biology & Neurodegeneration, Netherlands Institute for Neuroscience (NIN), An Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands; Synaptic Plasticity & Behavior, Netherlands Institute for Neuroscience (NIN), Amsterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
191
|
Milner E, Johnson AW, Nelson JW, Harries MD, Gidday JM, Han BH, Zipfel GJ. HIF-1α Mediates Isoflurane-Induced Vascular Protection in Subarachnoid Hemorrhage. Ann Clin Transl Neurol 2015; 2:325-37. [PMID: 25909079 PMCID: PMC4402079 DOI: 10.1002/acn3.170] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 12/11/2014] [Indexed: 01/05/2023] Open
Abstract
Objective Outcome after aneurysmal subarachnoid hemorrhage (SAH) depends critically on delayed cerebral ischemia (DCI) – a process driven primarily by vascular events including cerebral vasospasm, microvessel thrombosis, and microvascular dysfunction. This study sought to determine the impact of postconditioning – the phenomenon whereby endogenous protection against severe injury is enhanced by subsequent exposure to a mild stressor – on SAH-induced DCI. Methods Adult male C57BL/6 mice were subjected to sham, SAH, or SAH plus isoflurane postconditioning. Neurological outcome was assessed daily via sensorimotor scoring. Contributors to DCI including cerebral vasospasm, microvessel thrombosis, and microvascular dysfunction were measured 3 days later. Isoflurane-induced changes in hypoxia-inducible factor 1alpha (HIF-1α)-dependent genes were assessed via quantitative polymerase chain reaction. HIF-1α was inhibited pharmacologically via 2-methoxyestradiol (2ME2) or genetically via endothelial cell HIF-1α-null mice (EC-HIF-1α-null). All experiments were performed in a randomized and blinded fashion. Results Isoflurane postconditioning initiated at clinically relevant time points after SAH significantly reduced cerebral vasospasm, microvessel thrombosis, microvascular dysfunction, and neurological deficits in wild-type (WT) mice. Isoflurane modulated HIF-1α-dependent genes – changes that were abolished in 2ME2-treated WT mice and EC-HIF-1α-null mice. Isoflurane-induced DCI protection was attenuated in 2ME2-treated WT mice and EC-HIF-1α-null mice. Interpretation Isoflurane postconditioning provides strong HIF-1α-mediated macro- and microvascular protection in SAH, leading to improved neurological outcome. These results implicate cerebral vessels as a key target for the brain protection afforded by isoflurane postconditioning, and HIF-1α as a critical mediator of this vascular protection. They also identify isoflurane postconditioning as a promising novel therapeutic for SAH.
Collapse
Affiliation(s)
- Eric Milner
- Department of Neurological Surgery, Washington University School of Medicine St. Louis, Missouri, 63108 ; Program in Neuroscience, Washington University School of Medicine St. Louis, Missouri, 63108
| | - Andrew W Johnson
- Department of Neurological Surgery, Washington University School of Medicine St. Louis, Missouri, 63108
| | - James W Nelson
- Department of Neurological Surgery, Washington University School of Medicine St. Louis, Missouri, 63108
| | - Michael D Harries
- Department of Neurological Surgery, Washington University School of Medicine St. Louis, Missouri, 63108
| | - Jeffrey M Gidday
- Department of Neurological Surgery, Washington University School of Medicine St. Louis, Missouri, 63108 ; Hope Center for Neurological Disorders, Washington University School of Medicine St. Louis, Missouri, 63108
| | - Byung Hee Han
- Department of Neurological Surgery, Washington University School of Medicine St. Louis, Missouri, 63108 ; Hope Center for Neurological Disorders, Washington University School of Medicine St. Louis, Missouri, 63108
| | - Gregory J Zipfel
- Department of Neurological Surgery, Washington University School of Medicine St. Louis, Missouri, 63108 ; Hope Center for Neurological Disorders, Washington University School of Medicine St. Louis, Missouri, 63108 ; Department of Neurology, Washington University School of Medicine St. Louis, Missouri, 63108
| |
Collapse
|
192
|
Peixoto CA, Nunes AKS, Garcia-Osta A. Phosphodiesterase-5 Inhibitors: Action on the Signaling Pathways of Neuroinflammation, Neurodegeneration, and Cognition. Mediators Inflamm 2015; 2015:940207. [PMID: 26770022 PMCID: PMC4681825 DOI: 10.1155/2015/940207] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 11/08/2015] [Indexed: 12/16/2022] Open
Abstract
Phosphodiesterase type 5 inhibitors (PDE5-Is) have recently emerged as a potential therapeutic strategy for neuroinflammatory, neurodegenerative, and memory loss diseases. Mechanistically, PDE5-Is produce an anti-inflammatory and neuroprotection effect by increasing expression of nitric oxide synthases and accumulation of cGMP and activating protein kinase G (PKG), the signaling pathway of which is thought to play an important role in the development of several neurodiseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). The aim of this paper was to review present knowledge of the signaling pathways that underlie the use of PDE5-Is in neuroinflammation, neurogenesis, learning, and memory.
Collapse
Affiliation(s)
- Christina Alves Peixoto
- 1Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), 50.740-465 Recife, PE, Brazil
- *Christina Alves Peixoto:
| | - Ana Karolina Santana Nunes
- 1Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), 50.740-465 Recife, PE, Brazil
- 2Universidade Federal de Pernambuco, 50.670-901 Recife, PE, Brazil
| | - Ana Garcia-Osta
- 3Neurobiology of Alzheimer's disease, Neurosciences Division, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| |
Collapse
|
193
|
Freude K, Pires C, Hyttel P, Hall VJ. Induced Pluripotent Stem Cells Derived from Alzheimer's Disease Patients: The Promise, the Hope and the Path Ahead. J Clin Med 2014; 3:1402-36. [PMID: 26237610 PMCID: PMC4470192 DOI: 10.3390/jcm3041402] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 11/12/2014] [Accepted: 11/14/2014] [Indexed: 02/07/2023] Open
Abstract
The future hope of generated induced pluripotent stem cells (iPS cells) from Alzheimer’s disease patients is multifold. Firstly, they may help to uncover novel mechanisms of the disease, which could lead to the development of new and unprecedented drugs for patients and secondly, they could also be directly used for screening and testing of potential new compounds for drug discovery. In addition, in the case of familial known mutations, these cells could be targeted by use of advanced gene-editing techniques to correct the mutation and be used for future cell transplantation therapies. This review summarizes the work so far in regards to production and characterization of iPS cell lines from both sporadic and familial Alzheimer’s patients and from other iPS cell lines that may help to model the disease. It provides a detailed comparison between published reports and states the present hurdles we face with this new technology. The promise of new gene-editing techniques and accelerated aging models also aim to move this field further by providing better control cell lines for comparisons and potentially better phenotypes, respectively.
Collapse
Affiliation(s)
- Kristine Freude
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Gronnegaardsvej 7, Frederiksberg C DK-1870, Denmark.
| | - Carlota Pires
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Gronnegaardsvej 7, Frederiksberg C DK-1870, Denmark.
| | - Poul Hyttel
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Gronnegaardsvej 7, Frederiksberg C DK-1870, Denmark.
| | - Vanessa Jane Hall
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Gronnegaardsvej 7, Frederiksberg C DK-1870, Denmark.
| |
Collapse
|
194
|
Pekny M, Pekna M. Astrocyte reactivity and reactive astrogliosis: costs and benefits. Physiol Rev 2014; 94:1077-98. [PMID: 25287860 DOI: 10.1152/physrev.00041.2013] [Citation(s) in RCA: 606] [Impact Index Per Article: 60.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Astrocytes are the most abundant cells in the central nervous system (CNS) that provide nutrients, recycle neurotransmitters, as well as fulfill a wide range of other homeostasis maintaining functions. During the past two decades, astrocytes emerged also as increasingly important regulators of neuronal functions including the generation of new nerve cells and structural as well as functional synapse remodeling. Reactive gliosis or reactive astrogliosis is a term coined for the morphological and functional changes seen in astroglial cells/astrocytes responding to CNS injury and other neurological diseases. Whereas this defensive reaction of astrocytes is conceivably aimed at handling the acute stress, limiting tissue damage, and restoring homeostasis, it may also inhibit adaptive neural plasticity mechanisms underlying recovery of function. Understanding the multifaceted roles of astrocytes in the healthy and diseased CNS will undoubtedly contribute to the development of treatment strategies that will, in a context-dependent manner and at appropriate time points, modulate reactive astrogliosis to promote brain repair and reduce the neurological impairment.
Collapse
Affiliation(s)
- Milos Pekny
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Marcela Pekna
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| |
Collapse
|
195
|
Cantarella G, Di Benedetto G, Puzzo D, Privitera L, Loreto C, Saccone S, Giunta S, Palmeri A, Bernardini R. Neutralization of TNFSF10 ameliorates functional outcome in a murine model of Alzheimer's disease. ACTA ACUST UNITED AC 2014; 138:203-16. [PMID: 25472798 DOI: 10.1093/brain/awu318] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease is one of the most common causes of death worldwide, with poor treatment options. A tissue landmark of Alzheimer's disease is accumulation of the anomalous protein amyloid-β in specific brain areas. Whether inflammation is an effect of amyloid-β on the Alzheimer's disease brain, or rather it represents a cause for formation of amyloid plaques and intracellular tangles remains a subject of debate. TNFSF10, a proapoptotic cytokine of the TNF superfamily, is a mediator of amyloid-β neurotoxicity. Here, we demonstrate that blocking TNFSF10 by administration of a neutralizing monoclonal antibody could attenuate the amyloid-β-induced neurotoxicity in a triple transgenic mouse model of Alzheimer's disease (3xTg-AD). The effects of TNFSF10 neutralization on either cognitive parameters, as well as on the expression of TNFSF10, amyloid-β, inflammatory mediators and GFAP were studied in the hippocampus of 3xTg-AD mice. Treatment with the TNFSF10 neutralizing antibody resulted in dramatic improvement of cognitive parameters, as assessed by the Morris water maze test and the novel object recognition test. These results were correlated with decreased protein expression of TNFSF10, amyloid-β, inflammatory mediators and GFAP in the hippocampus. Finally, neutralization of TNFSF10 results in functional improvement and restrained immune/inflammatory response in the brain of 3xTg-AD mice in vivo. Thus, it is plausible to regard the TNFSF10 system as a potential target for efficacious treatment of amyloid-related disorders.
Collapse
Affiliation(s)
- Giuseppina Cantarella
- 1 Department of Clinical and Molecular Biomedicine, Section of Pharmacology and Biochemistry, University of Catania, 95125 Catania, Italy
| | - Giulia Di Benedetto
- 1 Department of Clinical and Molecular Biomedicine, Section of Pharmacology and Biochemistry, University of Catania, 95125 Catania, Italy 2 Li-Sa Laboratory, Department of Experimental Medicine, Section of Medical Physiopathology, Endocrinology and Nutrition, University of Roma 'La Sapienza', 00161 Rome, Italy
| | - Daniela Puzzo
- 3 Department of Bio-Medical Sciences, Section of Physiology, University of Catania, 95125 Catania, Italy
| | - Lucia Privitera
- 3 Department of Bio-Medical Sciences, Section of Physiology, University of Catania, 95125 Catania, Italy
| | - Carla Loreto
- 4 Department of Bio-Medical Sciences, Section of Anatomy and Histology, University of Catania, 95125 Catania, Italy
| | - Salvatore Saccone
- 5 Department of Biological, Geological and Environmental Sciences, Section of Animal Biology, University of Catania, 95125 Catania, Italy
| | - Salvatore Giunta
- 4 Department of Bio-Medical Sciences, Section of Anatomy and Histology, University of Catania, 95125 Catania, Italy
| | - Agostino Palmeri
- 3 Department of Bio-Medical Sciences, Section of Physiology, University of Catania, 95125 Catania, Italy
| | - Renato Bernardini
- 1 Department of Clinical and Molecular Biomedicine, Section of Pharmacology and Biochemistry, University of Catania, 95125 Catania, Italy
| |
Collapse
|
196
|
Norden DM, Muccigrosso MM, Godbout JP. Microglial priming and enhanced reactivity to secondary insult in aging, and traumatic CNS injury, and neurodegenerative disease. Neuropharmacology 2014; 96:29-41. [PMID: 25445485 DOI: 10.1016/j.neuropharm.2014.10.028] [Citation(s) in RCA: 279] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/26/2014] [Accepted: 10/30/2014] [Indexed: 12/14/2022]
Abstract
Glia of the central nervous system (CNS) help to maintain homeostasis in the brain and support efficient neuronal function. Microglia are innate immune cells of the brain that mediate responses to pathogens and injury. They have key roles in phagocytic clearing, surveying the local microenvironment and propagating inflammatory signals. An interruption in homeostasis induces a cascade of conserved adaptive responses in glia. This response involves biochemical, physiological and morphological changes and is associated with the production of cytokines and secondary mediators that influence synaptic plasticity, cognition and behavior. This reorganization of host priorities represents a beneficial response that is normally adaptive but may become maladaptive when the profile of microglia is compromised. For instance, microglia can develop a primed or pro-inflammatory mRNA, protein and morphological profile with aging, traumatic brain injury and neurodegenerative disease. As a result, primed microglia exhibit an exaggerated inflammatory response to secondary and sub-threshold challenges. Consequences of exaggerated inflammatory responses by microglia include the development of cognitive deficits, impaired synaptic plasticity and accelerated neurodegeneration. Moreover, impairments in regulatory systems in these circumstances may make microglia more resistant to negative feedback and important functions of glia can become compromised and dysfunctional. Overall, the purpose of this review is to discuss key concepts of microglial priming and immune-reactivity in the context of aging, traumatic CNS injury and neurodegenerative disease. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.
Collapse
Affiliation(s)
- Diana M Norden
- Department of Neuroscience, The Ohio State University, 333 W. 10th Ave, Columbus, OH 43210, USA
| | - Megan M Muccigrosso
- Department of Neuroscience, The Ohio State University, 333 W. 10th Ave, Columbus, OH 43210, USA
| | - Jonathan P Godbout
- Department of Neuroscience, The Ohio State University, 333 W. 10th Ave, Columbus, OH 43210, USA; Institute for Behavioral Medicine Research, The Ohio State University, 460 Medical Center Dr., Columbus, OH 43210, USA; Center for Brain and Spinal Cord Repair, The Ohio State University, 460 W. 12th Ave, Columbus, OH 43210, USA.
| |
Collapse
|
197
|
Hou Y, Wang Y, Zhao J, Li X, Cui J, Ding J, Wang Y, Zeng X, Ling Y, Shen X, Chen S, Huang C, Pei G. Smart Soup, a traditional Chinese medicine formula, ameliorates amyloid pathology and related cognitive deficits. PLoS One 2014; 9:e111215. [PMID: 25386946 PMCID: PMC4227681 DOI: 10.1371/journal.pone.0111215] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 09/28/2014] [Indexed: 01/30/2023] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disease that causes substantial public health care burdens. Intensive efforts have been made to find effective and safe disease-modifying treatment and symptomatic intervention alternatives against AD. Smart Soup (SS), a Chinese medicine formula composed of Rhizoma Acori Tatarinowii (AT), Poria cum Radix Pini (PRP) and Radix Polygalae (RP), is a typical prescription against memory deficits. Here, we assessed the efficacy of SS against AD. Oral administration of SS ameliorated the cognitive impairment of AD transgenic mice, with reduced Aβ levels, retarded Aβ amyloidosis and reduced Aβ-induced gliosis and neuronal loss in the brains of AD mice. Consistently, SS treatment reduced amyloid-related locomotor dysfunctions and premature death of AD transgenic Drosophila. Mechanistic studies showed that RP reduced Aβ generation, whereas AT and PRP exerted neuroprotective effects against Aβ. Taken together, our study indicates that SS could be effective against AD, providing a practical therapeutic strategy against the disease.
Collapse
Affiliation(s)
- Yujun Hou
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Ying Wang
- Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jian Zhao
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (GP); (JZ)
| | - Xiaohang Li
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jin Cui
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jianqing Ding
- Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ying Wang
- Department of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xianglu Zeng
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yun Ling
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xiaoheng Shen
- Department of Traditional Chinese Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Shengdi Chen
- Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Chenggang Huang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Gang Pei
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
- Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai, China
- * E-mail: (GP); (JZ)
| |
Collapse
|
198
|
Avila-Muñoz E, Arias C. When astrocytes become harmful: functional and inflammatory responses that contribute to Alzheimer's disease. Ageing Res Rev 2014; 18:29-40. [PMID: 25078115 DOI: 10.1016/j.arr.2014.07.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/03/2014] [Accepted: 07/21/2014] [Indexed: 12/24/2022]
Abstract
A growing body of research suggests that astrocytes play roles as contributors to the pathophysiology of Alzheimer's disease (AD). Several lines of evidence propose that activated astrocytes produce and release proinflammatory molecules that may be critical for the generation of amyloid-β peptide (Aβ). However, accumulating evidence indicates that Aβ may activate astrocytes, which leads to an increase in cytokines that has been suggested to be a causative factor in the cognitive dysfunction of AD; thus, a vicious circle may be created. Intrinsic inflammatory mechanisms may provide a regulatory system that is capable of influencing the neuronal microenvironment that affects neuronal survival. In this article, we address the evidence surrounding the interactions of dysfunctional astrocytes with neighboring neurons that may initiate a cascade of events that culminates with neuronal injury and the expression of the hallmark lesions of AD. Comprehensive knowledge of the molecular mechanisms underlying the participation of astrocytes in neurodegeneration could aid the development of therapies to restore proper astrocyte function that can be used in AD patients to prevent or alleviate the progression of the disease in a more efficient and comprehensive manner.
Collapse
|
199
|
Abstract
Exclusively neuron-centric approaches to neuropathological mechanisms have not resulted in major new breakthroughs in the prevention and therapy of neurodegenerative diseases. In the present paper, we review the role of glia in neurodegeneration in an attempt to identify novel targets that could be used to develop much-needed strategies for the containment and cure of neurodegenerative disorders. We discuss this in the context of glial roles in the homoeostasis and defence of the brain. We consider the mounting evidence supporting a change away from the perception of reactive glial responses merely as secondary detrimental processes that exacerbate the course of neurological disorders, in favour of an emerging contemporary view of glial pathological responses as complex and multistaged defensive processes that also have the potential for dysfunction.
Collapse
|
200
|
Abstract
Increased production of amyloid β-peptide (Aβ) and altered processing of tau in Alzheimer's disease (AD) are associated with synaptic dysfunction, neuronal death and cognitive and behavioural deficits. Neuroinflammation is also a prominent feature of AD brain and considerable evidence indicates that inflammatory events play a significant role in modulating the progression of AD. The role of microglia in AD inflammation has long been acknowledged. Substantial evidence now demonstrates that astrocyte-mediated inflammatory responses also influence pathology development, synapse health and neurodegeneration in AD. Several anti-inflammatory therapies targeting astrocytes show significant benefit in models of disease, particularly with respect to tau-associated neurodegeneration. However, the effectiveness of these approaches is complex, since modulating inflammatory pathways often has opposing effects on the development of tau and amyloid pathology, and is dependent on the precise phenotype and activities of astrocytes in different cellular environments. An increased understanding of interactions between astrocytes and neurons under different conditions is required for the development of safe and effective astrocyte-based therapies for AD and related neurodegenerative diseases.
Collapse
|