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Zhang PF, You WY, Gao YJ, Wu XB. Activation of pyramidal neurons in the infralimbic cortex alleviates LPS-induced depressive-like behavior in mice. Brain Res Bull 2024; 214:111008. [PMID: 38866373 DOI: 10.1016/j.brainresbull.2024.111008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/23/2024] [Accepted: 06/07/2024] [Indexed: 06/14/2024]
Abstract
The infralimbic (IL) cortex dysfunction has been implicated in major depressive disorder (MDD), yet the precise cellular and molecular mechanisms remain poorly understood. In this study, we investigated the role of layer V pyramidal neurons in a mouse model of MDD induced by repeated lipopolysaccharide (LPS) administration. Our results demonstrate that three days of systemic LPS administration induced depressive-like behavior and upregulated mRNA levels of interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and transforming growth factor-β (TGF-β) in the IL cortex. Electrophysiological recordings revealed a significant decrease in the intrinsic excitability of layer V pyramidal neurons in the IL following systemic LPS exposure. Importantly, chemogenetic activation of IL pyramidal neurons ameliorated LPS-induced depressive-like behavior. Additionally, LPS administration significantly increased microglial activity in the IL, as evidenced by a greater number of Ionized calcium binding adaptor molecule-1 (IBA-1)-positive cells. Morphometric analysis further unveiled enlarged soma, decreased branch numbers, and shorter branch lengths of microglial cells in the IL cortex following LPS exposure. Moreover, the activation of pyramidal neurons by clozapine-N-oxide increased the microglia branch length but did not change branch number or cytosolic area. These results collectively suggest that targeted activation of pyramidal neurons in the IL cortex mitigates microglial response and ameliorates depressive-like behaviors induced by systemic LPS administration. Therefore, our findings offer potential therapeutic targets for the development of interventions aimed at alleviating depressive symptoms by modulating IL cortical circuitry and microglial activity.
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Affiliation(s)
- Peng-Fei Zhang
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Wen-Yong You
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Yong-Jing Gao
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China.
| | - Xiao-Bo Wu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China.
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2
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Guerrero-Carrasco M, Targett I, Olmos-Alonso A, Vargas-Caballero M, Gomez-Nicola D. Low-grade systemic inflammation stimulates microglial turnover and accelerates the onset of Alzheimer's-like pathology. Glia 2024; 72:1340-1355. [PMID: 38597386 DOI: 10.1002/glia.24532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 03/22/2024] [Accepted: 03/26/2024] [Indexed: 04/11/2024]
Abstract
Several in vivo studies have shown that systemic inflammation, mimicked by LPS, triggers an inflammatory response in the CNS, driven by microglia, characterized by an increase in inflammatory cytokines and associated sickness behavior. However, most studies induce relatively high systemic inflammation, not directly compared with the more common low-grade inflammatory events experienced in humans during the life course. Using mice, we investigated the effects of low-grade systemic inflammation during an otherwise healthy early life, and how this may precondition the onset and severity of Alzheimer's disease (AD)-like pathology. Our results indicate that low-grade systemic inflammation induces sub-threshold brain inflammation and promotes microglial proliferation driven by the CSF1R pathway, contrary to the effects caused by high systemic inflammation. In addition, repeated systemic challenges with low-grade LPS induce disease-associated microglia. Finally, using an inducible model of AD-like pathology (Line 102 mice), we observed that preconditioning with repeated doses of low-grade systemic inflammation, prior to APP induction, promotes a detrimental effect later in life, leading to an increase in Aβ accumulation and disease-associated microglia. These results support the notion that episodic low-grade systemic inflammation has the potential to influence the onset and severity of age-related neurological disorders, such as AD.
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Affiliation(s)
- Monica Guerrero-Carrasco
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Imogen Targett
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Adrian Olmos-Alonso
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Mariana Vargas-Caballero
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
- Institute for Life Sciences (IfLS), University of Southampton, Southampton, UK
| | - Diego Gomez-Nicola
- School of Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
- Institute for Life Sciences (IfLS), University of Southampton, Southampton, UK
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3
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Chen Z, Balachandran YL, Chong WP, Chan KWY. Roles of Cytokines in Alzheimer's Disease. Int J Mol Sci 2024; 25:5803. [PMID: 38891990 PMCID: PMC11171747 DOI: 10.3390/ijms25115803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/18/2024] [Accepted: 05/24/2024] [Indexed: 06/21/2024] Open
Abstract
The neuroimmune system is a collection of immune cells, cytokines, and the glymphatic system that plays a pivotal role in the pathogenesis and progression of Alzheimer's disease (AD). Of particular focus are cytokines, a group of immune signaling molecules that facilitate communication among immune cells and contribute to inflammation in AD. Extensive research has shown that the dysregulated secretion of certain cytokines (IL-1β, IL-17, IL-12, IL-23, IL-6, and TNF-α) promotes neuroinflammation and exacerbates neuronal damage in AD. However, anti-inflammatory cytokines (IL-2, IL-3, IL-33, and IL-35) are also secreted during AD onset and progression, thereby preventing neuroinflammation. This review summarizes the involvement of pro- and anti-inflammatory cytokines in AD pathology and discusses their therapeutic potential.
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Affiliation(s)
- Zilin Chen
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (Z.C.); (Y.L.B.)
| | - Yekkuni L. Balachandran
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (Z.C.); (Y.L.B.)
| | - Wai Po Chong
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
- Institute for Research and Continuing Education, Hong Kong Baptist University, Shenzhen 518057, China
| | - Kannie W. Y. Chan
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (Z.C.); (Y.L.B.)
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
- Shenzhen Research Institute, City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
- Tung Biomedical Sciences Centre, City University of Hong Kong, Hong Kong, China
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4
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Windoloski KA, Janum S, Berg RMG, Olufsen MS. Characterization of differences in immune responses during bolus and continuous infusion endotoxin challenges using mathematical modelling. Exp Physiol 2024; 109:689-710. [PMID: 38466166 PMCID: PMC11061636 DOI: 10.1113/ep091552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/13/2024] [Indexed: 03/12/2024]
Abstract
Endotoxin administration is commonly used to study the inflammatory response, and though traditionally given as a bolus injection, it can be administered as a continuous infusion over multiple hours. Several studies hypothesize that the latter better represents the prolonged and pronounced inflammation observed in conditions like sepsis. Yet very few experimental studies have administered endotoxin using both strategies, leaving significant gaps in determining the underlying mechanisms responsible for their differing immune responses. We used mathematical modelling to analyse cytokine data from two studies administering a 2 ng kg-1 dose of endotoxin, one as a bolus and the other as a continuous infusion over 4 h. Using our model, we simulated the dynamics of mean and subject-specific cytokine responses as well as the response to long-term endotoxin administration. Cytokine measurements revealed that the bolus injection led to significantly higher peaks for interleukin (IL)-8, while IL-10 reaches higher peaks during continuous administration. Moreover, the peak timing of all measured cytokines occurred later with continuous infusion. We identified three model parameters that significantly differed between the two administration methods. Monocyte activation of IL-10 was greater during the continuous infusion, while tumour necrosis factor α $ {\alpha} $ and IL-8 recovery rates were faster for the bolus injection. This suggests that a continuous infusion elicits a stronger, longer-lasting systemic reaction through increased stimulation of monocyte anti-inflammatory mediator production and decreased recovery of pro-inflammatory catalysts. Furthermore, the continuous infusion model exhibited prolonged inflammation with recurrent peaks resolving within 2 days during long-term (20-32 h) endotoxin administration.
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Affiliation(s)
| | - Susanne Janum
- Frederiksberg and Bispebjerg HospitalsFrederiksbergDenmark
- Department of Biomedical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Ronan M. G. Berg
- Department of Biomedical SciencesUniversity of CopenhagenCopenhagenDenmark
- Department of Clinical Physiology and Nuclear Medicine and, Centre for Physical Activity ResearchCopenhagen University HospitalCopenhagenDenmark
- Neurovascular Research LaboratoryUniversity of South WalesPontypriddUK
| | - Mette S. Olufsen
- Department of MathematicsNorth Carolina State UniversityRaleighNorth CarolinaUSA
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5
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Bettinetti-Luque M, Trujillo-Estrada L, Garcia-Fuentes E, Andreo-Lopez J, Sanchez-Varo R, Garrido-Sánchez L, Gómez-Mediavilla Á, López MG, Garcia-Caballero M, Gutierrez A, Baglietto-Vargas D. Adipose tissue as a therapeutic target for vascular damage in Alzheimer's disease. Br J Pharmacol 2024; 181:840-878. [PMID: 37706346 DOI: 10.1111/bph.16243] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 08/11/2023] [Accepted: 09/01/2023] [Indexed: 09/15/2023] Open
Abstract
Adipose tissue has recently been recognized as an important endocrine organ that plays a crucial role in energy metabolism and in the immune response in many metabolic tissues. With this regard, emerging evidence indicates that an important crosstalk exists between the adipose tissue and the brain. However, the contribution of adipose tissue to the development of age-related diseases, including Alzheimer's disease, remains poorly defined. New studies suggest that the adipose tissue modulates brain function through a range of endogenous biologically active factors known as adipokines, which can cross the blood-brain barrier to reach the target areas in the brain or to regulate the function of the blood-brain barrier. In this review, we discuss the effects of several adipokines on the physiology of the blood-brain barrier, their contribution to the development of Alzheimer's disease and their therapeutic potential. LINKED ARTICLES: This article is part of a themed issue From Alzheimer's Disease to Vascular Dementia: Different Roads Leading to Cognitive Decline. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.6/issuetoc.
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Affiliation(s)
- Miriam Bettinetti-Luque
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Laura Trujillo-Estrada
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- CIBER de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Eduardo Garcia-Fuentes
- Unidad de Gestión Clínica Aparato Digestivo, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Málaga, Spain
- CIBER de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
| | - Juana Andreo-Lopez
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Raquel Sanchez-Varo
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- CIBER de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Departamento de Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Lourdes Garrido-Sánchez
- CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Unidad de Gestión Clínica de Endocrinología y Nutrición, Hospital Universitario Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Málaga, Spain
| | - Ángela Gómez-Mediavilla
- Departamento de Farmacología, Facultad de Medicina. Instituto Teófilo Hernando para la I+D de Fármacos, Universidad Autónoma de Madrid, Madrid, Spain
| | - Manuela G López
- Departamento de Farmacología, Facultad de Medicina. Instituto Teófilo Hernando para la I+D de Fármacos, Universidad Autónoma de Madrid, Madrid, Spain
- Instituto de Investigaciones Sanitarias (IIS-IP), Hospital Universitario de la Princesa, Madrid, Spain
| | - Melissa Garcia-Caballero
- Departamento de Biología Molecular y Bioquímica, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Antonia Gutierrez
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- CIBER de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - David Baglietto-Vargas
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA)-Plataforma BIONAND, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- CIBER de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
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6
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Voshart DC, Oshima T, Jiang Y, van der Linden GP, Ainslie AP, Reali Nazario L, van Buuren-Broek F, Scholma AC, van Weering HRJ, Brouwer N, Sewdihal J, Brouwer U, Coppes RP, Holtman IR, Eggen BJL, Kooistra SM, Barazzuol L. Radiotherapy induces persistent innate immune reprogramming of microglia into a primed state. Cell Rep 2024; 43:113764. [PMID: 38358885 DOI: 10.1016/j.celrep.2024.113764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 12/06/2023] [Accepted: 01/25/2024] [Indexed: 02/17/2024] Open
Abstract
Over half of patients with brain tumors experience debilitating and often progressive cognitive decline after radiotherapy treatment. Microglia, the resident macrophages in the brain, have been implicated in this decline. In response to various insults, microglia can develop innate immune memory (IIM), which can either enhance (priming or training) or repress (tolerance) the response to subsequent inflammatory challenges. Here, we investigate whether radiation affects the IIM of microglia by irradiating the brains of rats and later exposing them to a secondary inflammatory stimulus. Comparative transcriptomic profiling and protein validation of microglia isolated from irradiated rats show a stronger immune response to a secondary inflammatory insult, demonstrating that radiation can lead to long-lasting molecular reprogramming of microglia. Transcriptomic analysis of postmortem normal-appearing non-tumor brain tissue of patients with glioblastoma indicates that radiation-induced microglial priming is likely conserved in humans. Targeting microglial priming or avoiding further inflammatory insults could decrease radiotherapy-induced neurotoxicity.
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Affiliation(s)
- Daniëlle C Voshart
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Takuya Oshima
- Department of Biomedical Sciences, Section of Molecular Neurobiology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands
| | - Yuting Jiang
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Gideon P van der Linden
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Anna P Ainslie
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands; European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands
| | - Luiza Reali Nazario
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Fleur van Buuren-Broek
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Ayla C Scholma
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Hilmar R J van Weering
- Department of Biomedical Sciences, Section of Molecular Neurobiology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands
| | - Nieske Brouwer
- Department of Biomedical Sciences, Section of Molecular Neurobiology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands
| | - Jeffrey Sewdihal
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Uilke Brouwer
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Rob P Coppes
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Inge R Holtman
- Department of Biomedical Sciences, Section of Molecular Neurobiology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands
| | - Bart J L Eggen
- Department of Biomedical Sciences, Section of Molecular Neurobiology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands
| | - Susanne M Kooistra
- Department of Biomedical Sciences, Section of Molecular Neurobiology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands
| | - Lara Barazzuol
- Department of Biomedical Sciences, Section of Molecular Cell Biology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, the Netherlands; Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands.
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7
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Tsioti I, Steiner BL, Escher P, Zinkernagel MS, Benz PM, Kokona D. Systemic Lipopolysaccharide Exposure Exacerbates Choroidal Neovascularization in Mice. Ocul Immunol Inflamm 2024; 32:19-30. [PMID: 36441988 DOI: 10.1080/09273948.2022.2147547] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/08/2022] [Indexed: 11/29/2022]
Abstract
This study aims to investigate the effect of a systemic lipopolysaccharide (LPS) stimulus in the course of laser-induced choroidal neovascularization (CNV) in C57BL/6 J mice. A group of CNV-subjected mice received 1 mg/kg LPS via the tail vein immediately after CNV induction. Mouse eyes were monitored in vivo with fluorescein angiography for 2 weeks. In situ hybridization and flow cytometry were performed in the retina at different time points. LPS led to increased fluorescein leakage 3 days after CNV, correlated with a large influx of monocyte-derived macrophages and increase of pro-inflammatory microglia/macrophages in the retina. Additionally, LPS enhanced Vegfα mRNA expression by Glul-expressing cells but not Aif1 positive microglia/macrophages in the laser lesion. These findings suggest that systemic LPS exposure has transient detrimental effects in the course of CNV through activation of microglia/macrophages to a pro-inflammatory phenotype and supports the important role of these cells in the CNV course.
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Affiliation(s)
- Ioanna Tsioti
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Beatrice L Steiner
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Pascal Escher
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Martin S Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Peter M Benz
- Department of CardioMetabolic Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Despina Kokona
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
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8
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Martinez-Orengo N, Tahmazian S, Lai J, Wang Z, Sinharay S, Schreiber-Stainthorp W, Basuli F, Maric D, Reid W, Shah S, Hammoud DA. Assessing organ-level immunoreactivity in a rat model of sepsis using TSPO PET imaging. Front Immunol 2022; 13:1010263. [PMID: 36439175 PMCID: PMC9685400 DOI: 10.3389/fimmu.2022.1010263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/17/2022] [Indexed: 11/11/2022] Open
Abstract
There is current need for new approaches to assess/measure organ-level immunoreactivity and ensuing dysfunction in systemic inflammatory response syndrome (SIRS) and sepsis, in order to protect or recover organ function. Using a rat model of systemic sterile inflammatory shock (intravenous LPS administration), we performed PET imaging with a translocator protein (TSPO) tracer, [18F]DPA-714, as a biomarker for reactive immunoreactive changes in the brain and peripheral organs. In vivo dynamic PET/CT scans showed increased [18F]DPA-714 binding in the brain, lungs, liver and bone marrow, 4 hours after LPS injection. Post-LPS mean standard uptake values (SUVmean) at equilibrium were significantly higher in those organs compared to baseline. Changes in spleen [18F]DPA-714 binding were variable but generally decreased after LPS. SUVmean values in all organs, except the spleen, positively correlated with several serum cytokines/chemokines. In vitro measures of TSPO expression and immunofluorescent staining validated the imaging results. Noninvasive molecular imaging with [18F]DPA-714 PET in a rat model of systemic sterile inflammatory shock, along with in vitro measures of TSPO expression, showed brain, liver and lung inflammation, spleen monocytic efflux/lymphocytic activation and suggested increased bone marrow hematopoiesis. TSPO PET imaging can potentially be used to quantify SIRS and sepsis-associated organ-level immunoreactivity and assess the effectiveness of therapeutic and preventative approaches for associated organ failures, in vivo.
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Affiliation(s)
- Neysha Martinez-Orengo
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Sarine Tahmazian
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Jianhao Lai
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Zeping Wang
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Sanhita Sinharay
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - William Schreiber-Stainthorp
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Falguni Basuli
- Chemistry and Synthesis Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD, United States
| | - Dragan Maric
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - William Reid
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Swati Shah
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Dima A. Hammoud
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
- *Correspondence: Dima A. Hammoud,
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9
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Lima MN, Barbosa-Silva MC, Maron-Gutierrez T. Microglial Priming in Infections and Its Risk to Neurodegenerative Diseases. Front Cell Neurosci 2022; 16:878987. [PMID: 35783096 PMCID: PMC9240317 DOI: 10.3389/fncel.2022.878987] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/26/2022] [Indexed: 11/29/2022] Open
Abstract
Infectious diseases of different etiologies have been associated with acute and long-term neurological consequences. The primary cause of these consequences appears to be an inflammatory process characterized primarily by a pro-inflammatory microglial state. Microglial cells, the local effectors’ cells of innate immunity, once faced by a stimulus, alter their morphology, and become a primary source of inflammatory cytokines that increase the inflammatory process of the brain. This inflammatory scenario exerts a critical role in the pathogenesis of neurodegenerative diseases. In recent years, several studies have shown the involvement of the microglial inflammatory response caused by infections in the development of neurodegenerative diseases. This has been associated with a transitory microglial state subsequent to an inflammatory response, known as microglial priming, in which these cells are more responsive to stimuli. Thus, systemic inflammation and infections induce a transitory state in microglia that may lead to changes in their state and function, making priming them for subsequent immune challenges. However, considering that microglia are long-lived cells and are repeatedly exposed to infections during a lifetime, microglial priming may not be beneficial. In this review, we discuss the relationship between infections and neurodegenerative diseases and how this may rely on microglial priming.
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Affiliation(s)
- Maiara N. Lima
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Fiocruz, Rio de Janeiro, Brazil
| | - Maria C. Barbosa-Silva
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Fiocruz, Rio de Janeiro, Brazil
| | - Tatiana Maron-Gutierrez
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Fiocruz, Rio de Janeiro, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation, Rio de Janeiro, Brazil
- *Correspondence: Tatiana Maron-Gutierrez;
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10
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Puris E, Kouřil Š, Najdekr L, Auriola S, Loppi S, Korhonen P, Gómez-Budia M, Fricker G, Kanninen KM, Malm T, Friedecký D, Gynther M. Metabolomic, lipidomic and proteomic characterisation of lipopolysaccharide-induced inflammation mouse model. Neuroscience 2022; 496:165-178. [DOI: 10.1016/j.neuroscience.2022.05.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/20/2022] [Accepted: 05/23/2022] [Indexed: 11/28/2022]
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11
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Schütze S, Döpke A, Kellert B, Seele J, Ballüer M, Bunkowski S, Kreutzfeldt M, Brück W, Nau R. Intracerebral Infection with E. coli Impairs Spatial Learning and Induces Necrosis of Hippocampal Neurons in the Tg2576 Mouse Model of Alzheimer’s Disease. J Alzheimers Dis Rep 2022; 6:101-114. [PMID: 35530117 PMCID: PMC9028720 DOI: 10.3233/adr-210049] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 02/15/2022] [Indexed: 11/15/2022] Open
Abstract
Background: In patients with Alzheimer’s disease (AD), bacterial infections are often associated with a cognitive decline. Animal models of genuine acute infections with viable bacteria which induce deterioration of neurodegenerative diseases are missing. Objective: We assessed the effect of an intracerebral infection with E. coli in a mouse model of AD. Methods: 13-month-old Tg2576 +/- mice and transgene negative littermates (Tg2576 -/-) received an intracerebral injection with E. coli K1 or saline followed by treatment with ceftriaxone starting 41 h post infection (p.i.) for 5 days. For 4 weeks, mice were monitored for clinical status, weight, motor functions, and neuropsychological status using the Morris water maze. ELISAs, stainings, and immunohistochemistry in brains were performed at the end of the experiment. Results: Mortality of the infection was approximately 20%. After 4 weeks, spatial learning of infected Tg2576 +/- mice was compromised compared to non-infected Tg2576 +/- mice (p < 0.05). E. coli infection did not influence spatial learning in Tg2576 -/- mice, or spatial memory in both Tg2576 +/- and -/- mice within 4 weeks p.i.. Necrosis of hippocampal neurons was induced in infected compared to non-infected Tg2576 +/- mice 4 weeks p.i., whereas brain concentrations of Aβ1–40, Aβ1–42, and phosphoTau as well as axonal damage and microglia density were not altered. Conclusion: Here, we proved in principle that a genuine acute bacterial infection can worsen cognitive functions of AD mice. Mouse models of subacute systemic infections are needed to develop new strategies for the treatment of bacterial infections in patients with AD in order to minimize their cognitive decline.
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Affiliation(s)
- Sandra Schütze
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
- Department of Geriatrics, Neurogeriatric Section, AGAPLESION Frankfurter Diakonie Kliniken, Frankfurt, Germany
| | - Anika Döpke
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Benedikt Kellert
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Jana Seele
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Melissa Ballüer
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Stephanie Bunkowski
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Mario Kreutzfeldt
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
- Department of Pathology and Immunology, University of Geneva and Division of Clinical Pathology, Geneva University Hospital, Centre Médical Universitaire, Geneva, Switzerland
| | - Wolfgang Brück
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Roland Nau
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
- Department of Geriatrics, Evangelisches Krankenhaus Göttingen-Weende, Göttingen, Germany
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12
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Xie J, Van Hoecke L, Vandenbroucke RE. The Impact of Systemic Inflammation on Alzheimer's Disease Pathology. Front Immunol 2022; 12:796867. [PMID: 35069578 PMCID: PMC8770958 DOI: 10.3389/fimmu.2021.796867] [Citation(s) in RCA: 79] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating age-related neurodegenerative disorder with an alarming increasing prevalence. Except for the recently FDA-approved Aducanumab of which the therapeutic effect is not yet conclusively proven, only symptomatic medication that is effective for some AD patients is available. In order to be able to design more rational and effective treatments, our understanding of the mechanisms behind the pathogenesis and progression of AD urgently needs to be improved. Over the last years, it became increasingly clear that peripheral inflammation is one of the detrimental factors that can contribute to the disease. Here, we discuss the current understanding of how systemic and intestinal (referred to as the gut-brain axis) inflammatory processes may affect brain pathology, with a specific focus on AD. Moreover, we give a comprehensive overview of the different preclinical as well as clinical studies that link peripheral Inflammation to AD initiation and progression. Altogether, this review broadens our understanding of the mechanisms behind AD pathology and may help in the rational design of further research aiming to identify novel therapeutic targets.
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Affiliation(s)
- Junhua Xie
- VIB Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Lien Van Hoecke
- VIB Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Roosmarijn E Vandenbroucke
- VIB Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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13
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Amyloid Beta Pathology Exacerbates Weight Loss and Brain Cytokine Responses following Low-Dose Lipopolysaccharide in Aged Female Tg2576 Mice. Int J Mol Sci 2022; 23:ijms23042377. [PMID: 35216491 PMCID: PMC8879430 DOI: 10.3390/ijms23042377] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 02/12/2022] [Indexed: 12/27/2022] Open
Abstract
Systemic inflammation has been implicated in the progression of Alzheimer’s disease (AD); however, less is understood about how existing AD pathology contributes to adverse outcomes following acute inflammatory insults. In the present study, our goal was to determine how AD-associated amyloid beta (Aβ) pathology influences the acute neuroinflammatory and behavioral responses to a moderate systemic inflammatory insult. We treated 16–18-month-old female Tg2576 (Tg) mice, which overproduce human Aβ and develop plaques, and age-matched wild-type (WT) littermate mice with an intraperitoneal injection of 0.33 mg/kg lipopolysaccharide (LPS) or saline. Mice were then evaluated over the next 28 h for sickness/depressive-like behaviors (food intake, weight loss, locomotion, and sucrose preference), systemic inflammation (serum amyloid A, SAA), blood-brain barrier (BBB) disruption, astrogliosis (glial fibrillary acidic protein/GFAP), Aβ, and cytokine levels in the brain. We found that LPS caused a larger reduction in body weight in Tg vs. WT mice, but that other behavioral responses to LPS did not differ by genotype. BBB disruption was not apparent in either genotype following LPS. Concentrations of the systemic inflammatory marker, SAA, in the blood and brain were significantly increased with LPS but did not significantly differ by genotype. GFAP was increased in Tg mice vs. WT but was not significantly affected by LPS in either genotype. Finally, LPS-induced increases of eight cytokines (IL-1β, IL-6, IL-12 (p40), IL-10, IL-17A, MIP-1α/CCL3, MIP-1β/CCL4, and RANTES/CCL5) were found to be significantly higher in Tg mice vs. WT. In summary, our data show that Aβ pathology exacerbates the neuroinflammatory response to LPS and identifies cytokines that are selectively regulated by Aβ. The association of worse neuroinflammation with greater weight loss in Tg mice suggests that Aβ pathology could contribute to poor outcomes following a systemic inflammatory insult.
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14
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Pathway-specific TNF-mediated metaplasticity in hippocampal area CA1. Sci Rep 2022; 12:1746. [PMID: 35110639 PMCID: PMC8810872 DOI: 10.1038/s41598-022-05844-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 01/19/2022] [Indexed: 01/29/2023] Open
Abstract
Long-term potentiation (LTP) is regulated in part by metaplasticity, the activity-dependent alterations in neural state that coordinate the direction, amplitude, and persistence of future synaptic plasticity. Previously, we documented a heterodendritic metaplasticity effect whereby high-frequency priming stimulation in stratum oriens (SO) of hippocampal CA1 suppressed subsequent LTP in the stratum radiatum (SR). The cytokine tumor necrosis factor (TNF) mediated this heterodendritic metaplasticity in wild-type rodents and in a mouse model of Alzheimer’s disease. Here, we investigated whether LTP at other afferent synapses to CA1 pyramidal cells were similarly affected by priming stimulation. We found that priming stimulation in SO inhibited LTP only in SR and not in a second independent pathway in SO, nor in stratum lacunosum moleculare (SLM). Synapses in SR were also more sensitive than SO or SLM to the LTP-inhibiting effects of pharmacological TNF priming. Neither form of priming was sex-specific, while the metaplasticity effects were absent in TNFR1 knock-out mice. Our findings demonstrate an unexpected pathway specificity for the heterodendritic metaplasticity in CA1. That Schaffer collateral/commissural synapses in SR are particularly susceptible to such metaplasticity may reflect an important control of information processing in this pathway in addition to its sensitivity to neuroinflammation under disease conditions.
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15
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Wang XL, Li L. Circadian Clock Regulates Inflammation and the Development of Neurodegeneration. Front Cell Infect Microbiol 2021; 11:696554. [PMID: 34595127 PMCID: PMC8476957 DOI: 10.3389/fcimb.2021.696554] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/18/2021] [Indexed: 12/15/2022] Open
Abstract
The circadian clock regulates numerous key physiological processes and maintains cellular, tissue, and systemic homeostasis. Disruption of circadian clock machinery influences key activities involved in immune response and brain function. Moreover, Immune activation has been closely linked to neurodegeneration. Here, we review the molecular clock machinery and the diurnal variation of immune activity. We summarize the circadian control of immunity in both central and peripheral immune cells, as well as the circadian regulation of brain cells that are implicated in neurodegeneration. We explore the important role of systemic inflammation on neurodegeneration. The circadian clock modulates cellular metabolism, which could be a mechanism underlying circadian control. We also discuss the circadian interventions implicated in inflammation and neurodegeneration. Targeting circadian clocks could be a potential strategy for the prevention and treatment of inflammation and neurodegenerative diseases.
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Affiliation(s)
- Xiao-Lan Wang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lianjian Li
- Department of Surgery, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China.,Hubei Province Academy of Traditional Chinese Medicine, Wuhan, China
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16
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Kurach Ł, Kulczycka-Mamona S, Kowalczyk J, Skalicka-Woźniak K, Boguszewska-Czubara A, El Sayed N, Osmani M, Iwaniak K, Budzyńska B. Mechanisms of the Procognitive Effects of Xanthotoxin and Umbelliferone on LPS-Induced Amnesia in Mice. Int J Mol Sci 2021; 22:1779. [PMID: 33579030 PMCID: PMC7916770 DOI: 10.3390/ijms22041779] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 02/06/2021] [Accepted: 02/07/2021] [Indexed: 12/23/2022] Open
Abstract
Neuroinflammation plays an essential role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease. Although coumarins have been shown to improve cognitive function in animal models and exert anti-inflammatory effects in cell cultures, the exact mechanism of their neuroprotective effects has not yet been fully elucidated. The present study aimed to investigate the neuroprotective effects of xanthotoxin (furanocoumarin) and umbelliferone (simple coumarin) in lipopolysaccharide-induced cognitive dysfunction in mice. For evaluation memory and learning processes, a passive avoidance test was used. Furthermore, acetylcholinesterase level and impact on the tumor necrosis factor α, interleukin 10 levels in the whole brain, and cyclooxygenase-II in hippocampus was established. Subchronic administration of both coumarins (15 mg/kg) enhanced the learning and memory function, but only the xanthotoxin improved cognitive processes impaired by lipopolysaccharide (0.8 mg/kg) administration. Behavioral results stay in line with acetylcholinesterase level in the brain. A statistically significant decrease in the level of tumor necrosis factor α and cyclooxygenase-II in lipopolysaccharide-treated rodents after coumarins' administration was observed. Together, our findings demonstrate that both coumarins improved cognitive functions, but only xanthotoxin significantly enhanced the learning and memory function and reduced the level of acetylcholinesterase in lipopolysaccharide-treated mice. This effect may suggest that only furanocoumarin-xanthotoxin attenuates neuroinflammation and enhances cholinergic neurotransmission, thus it can be a potential remedy with procognitive potential effective in treatment of neuroinflammatory disease.
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Affiliation(s)
- Łukasz Kurach
- Independent Laboratory of Behavioral Studies, Medical University of Lublin, 4A Chodzki Str., 20-093 Lublin, Poland;
| | - Sylwia Kulczycka-Mamona
- Department of Applied Pharmacy, Medical University of Lublin, 1 Chodzki Str., 20-093 Lublin, Poland; (S.K.-M.); (J.K.); (K.I.)
| | - Joanna Kowalczyk
- Department of Applied Pharmacy, Medical University of Lublin, 1 Chodzki Str., 20-093 Lublin, Poland; (S.K.-M.); (J.K.); (K.I.)
| | - Krystyna Skalicka-Woźniak
- Independent Laboratory of Natural Products Chemistry, Medical University of Lublin, 1 Chodzki Str., 20-093 Lublin, Poland;
| | - Anna Boguszewska-Czubara
- Department of Medicinal Chemistry, Medical University of Lublin, 4A Chodzki Str., 20-093 Lublin, Poland;
| | - Nesrine El Sayed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt;
| | - Mitat Osmani
- Department of Pharmacy, University of Pristina, St. Bulevardi i Dëshmorëve, 10000 Pristina, Kosovo;
| | - Karol Iwaniak
- Department of Applied Pharmacy, Medical University of Lublin, 1 Chodzki Str., 20-093 Lublin, Poland; (S.K.-M.); (J.K.); (K.I.)
| | - Barbara Budzyńska
- Independent Laboratory of Behavioral Studies, Medical University of Lublin, 4A Chodzki Str., 20-093 Lublin, Poland;
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17
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Ren S, Breuillaud L, Yao W, Yin T, Norris KA, Zehntner SP, D'Adamio L. TNF-α-mediated reduction in inhibitory neurotransmission precedes sporadic Alzheimer's disease pathology in young Trem2 R47H rats. J Biol Chem 2021; 296:100089. [PMID: 33434745 PMCID: PMC7949092 DOI: 10.1074/jbc.ra120.016395] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/14/2020] [Accepted: 11/16/2020] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative dementia associated with deposition of amyloid plaques and neurofibrillary tangles, formed by amyloid β (Aβ) peptides and phosphor-tau, respectively, in the central nervous system. Approximately 2% of AD cases are due to familial AD (FAD); ∼98% of cases are sporadic AD (SAD). Animal models with FAD are commonly used to study SAD pathogenesis. Because mechanisms leading to FAD and SAD may be distinct, to study SAD pathogenesis, we generated Trem2R47H knock-in rats, which carry the SAD risk factor p.R47H variant of the microglia gene triggering receptor expressed on myeloid cells 2 (TREM2). Trem2R47H rats produce human-Aβ from a humanized-App rat allele because human-Aβ is more toxic than rodent-Aβ and the pathogenic role of the p.R47H TREM2 variant has been linked to human-Aβ-clearing deficits. Using periadolescent Trem2R47H rats, we previously demonstrated that supraphysiological tumor necrosis factor-α (TNF-α) boosts glutamatergic transmission, which is excitatory, and suppresses long-term potentiation, a surrogate of learning and memory. Here, we tested the effect of the p.R47H variant on the inhibitory neurotransmitter γ-aminobutyric acid. We report that GABAergic transmission is decreased in Trem2R47H/R47H rats. This decrease is due to acute and reversible action of TNF-α and is not associated with increased human-Aβ levels and AD pathology. Thus, the p.R47H variant changes the excitatory/inhibitory balance, favoring excitation. This imbalance could potentiate glutamate excitotoxicity and contribute to neuronal dysfunction, enhanced neuronal death, and neurodegeneration. Future studies will determine whether this imbalance represents an early, Aβ-independent pathway leading to dementia and may reveal the AD-modifying therapeutic potential of TNF-α inhibition in the central nervous system.
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Affiliation(s)
- Siqiang Ren
- Department of Pharmacology, Physiology & Neuroscience New Jersey Medical School, Brain Health Institute, Jacqueline Krieger Klein Center in Alzheimer's Disease and Neurodegeneration Research, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | | | - Wen Yao
- Department of Pharmacology, Physiology & Neuroscience New Jersey Medical School, Brain Health Institute, Jacqueline Krieger Klein Center in Alzheimer's Disease and Neurodegeneration Research, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Tao Yin
- Department of Pharmacology, Physiology & Neuroscience New Jersey Medical School, Brain Health Institute, Jacqueline Krieger Klein Center in Alzheimer's Disease and Neurodegeneration Research, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | - Kelly A Norris
- Department of Pharmacology, Physiology & Neuroscience New Jersey Medical School, Brain Health Institute, Jacqueline Krieger Klein Center in Alzheimer's Disease and Neurodegeneration Research, Rutgers, The State University of New Jersey, Newark, New Jersey, USA
| | | | - Luciano D'Adamio
- Department of Pharmacology, Physiology & Neuroscience New Jersey Medical School, Brain Health Institute, Jacqueline Krieger Klein Center in Alzheimer's Disease and Neurodegeneration Research, Rutgers, The State University of New Jersey, Newark, New Jersey, USA.
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18
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Paouri E, Georgopoulos S. Systemic and CNS Inflammation Crosstalk: Implications for Alzheimer's Disease. Curr Alzheimer Res 2020; 16:559-574. [PMID: 30907316 DOI: 10.2174/1567205016666190321154618] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 02/26/2019] [Accepted: 03/19/2019] [Indexed: 12/14/2022]
Abstract
After years of failed therapeutic attempts targeting beta-amyloid (Aβ) in AD, there is now increasing evidence suggesting that inflammation holds a pivotal role in AD pathogenesis and immune pathways can possibly comprise primary therapeutic targets. Inflammation is a key characteristic of numerous diseases including neurodegenerative disorders and thus not surprisingly suppression of inflammation frequently constitutes a major therapeutic strategy for a wide spectrum of disorders. Several brain-resident and peripherally-derived immune populations and inflammatory mediators are involved in AD pathophysiology, with microglia comprising central cellular player in the disease process. Systemic inflammation, mostly in the form of infections, has long been observed to induce behavioral alterations and cognitive dysfunction, suggesting for a close interaction of the peripheral immune system with the brain. Systemic inflammation can result in neuroinflammation, mainly exhibited as microglial activation, production of inflammatory molecules, as well as recruitment of peripheral immune cells in the brain, thus shaping a cerebral inflammatory milieu that may seriously impact neuronal function. Increasing clinical and experimental studies have provided significant evidence that acute (e.g. infections) or chronic (e.g. autoimmune diseases like rheumatoid arthritis) systemic inflammatory conditions may be associated with increased AD risk and accelerate AD progression. Here we review the current literature that links systemic with CNS inflammation and the implications of this interaction for AD in the context of acute and chronic systemic pathologies as acute infection and rheumatoid arthritis. Elucidating the mechanisms that govern the crosstalk between the peripheral and the local brain immune system may provide the ground for new therapeutic approaches that target the immune-brain interface and shed light on the understanding of AD.
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Affiliation(s)
- Evi Paouri
- Laboratory of Cellular Neurobiology, Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Spiros Georgopoulos
- Laboratory of Cellular Neurobiology, Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece
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19
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Drieu A, Lanquetin A, Levard D, Glavan M, Campos F, Quenault A, Lemarchand E, Naveau M, Pitel AL, Castillo J, Vivien D, Rubio M. Alcohol exposure-induced neurovascular inflammatory priming impacts ischemic stroke and is linked with brain perivascular macrophages. JCI Insight 2020; 5:129226. [PMID: 31990687 DOI: 10.1172/jci.insight.129226] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 01/15/2020] [Indexed: 02/06/2023] Open
Abstract
Alcohol abuse is a major public health problem worldwide, causing a wide range of preventable morbidity and mortality. In this translational study, we show that heavy drinking (HD) (≥6 standard drinks/day) is independently associated with a worse outcome for ischemic stroke patients. To study the underlying mechanisms of this deleterious effect of HD, we performed an extensive analysis of the brain inflammatory responses of mice chronically exposed or not to 10% alcohol before and after ischemic stroke. Inflammatory responses were analyzed at the parenchymal, perivascular, and vascular levels by using transcriptomic, immunohistochemical, in vivo 2-photon microscopy and molecular MRI analyses. Alcohol-exposed mice show, in the absence of any other insult, a neurovascular inflammatory priming (i.e., an abnormal inflammatory status including an increase in brain perivascular macrophages [PVM]) associated with exacerbated inflammatory responses after a secondary insult (ischemic stroke or LPS challenge). Similar to our clinical data, alcohol-exposed mice showed larger ischemic lesions. We show here that PVM are key players on this aggravating effect of alcohol, since their specific depletion blocks the alcohol-induced aggravation of ischemic lesions. This study opens potentially new therapeutic avenues aiming at blocking alcohol-induced exacerbation of the neurovascular inflammatory responses triggered after ischemic stroke.
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Affiliation(s)
- Antoine Drieu
- INSERM, Physiopathology and Imaging of Neurological Disorders, UMR-S 1237, Normandie Université, Caen, France
| | - Anastasia Lanquetin
- INSERM, Physiopathology and Imaging of Neurological Disorders, UMR-S 1237, Normandie Université, Caen, France
| | - Damien Levard
- INSERM, Physiopathology and Imaging of Neurological Disorders, UMR-S 1237, Normandie Université, Caen, France
| | - Martina Glavan
- INSERM, Physiopathology and Imaging of Neurological Disorders, UMR-S 1237, Normandie Université, Caen, France
| | - Francisco Campos
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Aurélien Quenault
- INSERM, Physiopathology and Imaging of Neurological Disorders, UMR-S 1237, Normandie Université, Caen, France
| | - Eloïse Lemarchand
- INSERM, Physiopathology and Imaging of Neurological Disorders, UMR-S 1237, Normandie Université, Caen, France
| | - Mikaël Naveau
- CNRS, UMR-S 3408, GIP Cyceron, Normandie Université, Caen, France
| | - Anne Lise Pitel
- INSERM, Neuropsychologie et Imagerie de la Mémoire Humaine, UMR-S 1077, Université Paris Sciences et Lettres, Caen, France
| | - José Castillo
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Denis Vivien
- INSERM, Physiopathology and Imaging of Neurological Disorders, UMR-S 1237, Normandie Université, Caen, France
| | - Marina Rubio
- INSERM, Physiopathology and Imaging of Neurological Disorders, UMR-S 1237, Normandie Université, Caen, France
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20
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Su D, Li W, Chi H, Yang H, She X, Wang K, Gao X, Ma K, Zhang M, Cui B. Transcriptome analysis of the hippocampus in environmental noise-exposed SAMP8 mice reveals regulatory pathways associated with Alzheimer's disease neuropathology. Environ Health Prev Med 2020; 25:3. [PMID: 31918655 PMCID: PMC6953163 DOI: 10.1186/s12199-019-0840-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/22/2019] [Indexed: 12/31/2022] Open
Abstract
Background Chronic noise exposure is one environmental hazard that is associated with genetic susceptibility factors that increase Alzheimer’s disease (AD) pathogenesis. However, the comprehensive understanding of the link between chronic noise stress and AD is limited. Herein, we investigated the effects of chronic noise exposure on AD-like changes in senescence-accelerated mouse prone 8 (SAMP8). Methods A total of 30 male SAMP8 mice were randomly divided into the noise-exposed group, the control group, and aging group (positive controls), and mice in the exposure group were exposed to 98 dB SPL white noise for 30 consecutive days. Transcriptome analysis and AD-like neuropathology of hippocampus were examined by RNA sequencing and immunoblotting. Enzyme-linked immunosorbent assay and real-time PCR were used to further determine the differential gene expression and explore the underlying mechanisms of chronic noise exposure in relation to AD at the genome level. Results Chronic noise exposure led to amyloid beta accumulation and increased the hyperphosphorylation of tau at the Ser202 and Ser404 sites in young SAMP8 mice; similar observations were noted in aging SAMP8 mice. We identified 21 protein-coding transcripts that were differentially expressed: 6 were downregulated and 15 were upregulated after chronic noise exposure; 8 genes were related to AD. qPCR results indicated that the expression of Arc, Egr1, Egr2, Fos, Nauk1, and Per2 were significantly high in the noise exposure group. These outcomes mirrored the results of the RNA sequencing data. Conclusions These findings further revealed that chronic noise exposure exacerbated aging-like impairment in the hippocampus of the SAMP8 mice and that the protein-coding transcripts discovered in the study may be key candidate regulators involved in environment-gene interactions.
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Affiliation(s)
- Donghong Su
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Wenlong Li
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Huimin Chi
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China.,School of Public Health and Management, Weifang Medical University, Weifang, China
| | - Honglian Yang
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Xiaojun She
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Kun Wang
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Xiujie Gao
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Kefeng Ma
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Ming Zhang
- Tianjin Centers for Disease Control and Prevention, Tianjin, China.
| | - Bo Cui
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China.
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21
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Nyunt T, Britton M, Wanichthanarak K, Budamagunta M, Voss JC, Wilson DW, Rutledge JC, Aung HH. Mitochondrial oxidative stress-induced transcript variants of ATF3 mediate lipotoxic brain microvascular injury. Free Radic Biol Med 2019; 143:25-46. [PMID: 31356870 PMCID: PMC6848793 DOI: 10.1016/j.freeradbiomed.2019.07.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 06/30/2019] [Accepted: 07/23/2019] [Indexed: 12/06/2022]
Abstract
Elevation of blood triglycerides, primarily triglyceride-rich lipoproteins (TGRL), is an independent risk factor for cardiovascular disease and vascular dementia (VaD). Accumulating evidence indicates that both atherosclerosis and VaD are linked to vascular inflammation. However, the role of TGRL in vascular inflammation, which increases risk for VaD, remains largely unknown and its underlying mechanisms are still unclear. We strived to determine the effects of postprandial TGRL exposure on brain microvascular endothelial cells, the potential risk factor of vascular inflammation, resulting in VaD. We showed in Aung et al., J Lipid Res., 2016 that postprandial TGRL lipolysis products (TL) activate mitochondrial reactive oxygen species (ROS) and increase the expression of the stress-responsive protein, activating transcription factor 3 (ATF3), which injures human brain microvascular endothelial cells (HBMECs) in vitro. In this study, we deployed high-throughput sequencing (HTS)-based RNA sequencing methods and mito stress and glycolytic rate assays with an Agilent Seahorse XF analyzer and profiled the differential expression of transcripts, constructed signaling pathways, and measured mitochondrial respiration, ATP production, proton leak, and glycolysis of HBMECs treated with TL. Conclusions: TL potentiate ROS by mitochondria which activate mitochondrial oxidative stress, decrease ATP production, increase mitochondrial proton leak and glycolysis rate, and mitochondria DNA damage. Additionally, CPT1A1 siRNA knockdown suppresses oxidative stress and prevents mitochondrial dysfunction and vascular inflammation in TL treated HBMECs. TL activates ATF3-MAPKinase, TNF, and NRF2 signaling pathways. Furthermore, the NRF2 signaling pathway which is upstream of the ATF3-MAPKinase signaling pathway, is also regulated by the mitochondrial oxidative stress. We are the first to report differential inflammatory characteristics of transcript variants 4 (ATF3-T4) and 5 (ATF3-T5) of the stress responsive gene ATF3 in HBMECs induced by postprandial TL. Specifically, our data indicates that ATF3-T4 predominantly regulates the TL-induced brain microvascular inflammation and TNF signaling. Both siRNAs of ATF3-T4 and ATF3-T5 suppress cells apoptosis and lipotoxic brain microvascular endothelial cells. These novel signaling pathways triggered by oxidative stress-responsive transcript variants, ATF3-T4 and ATF3-T5, in the brain microvascular inflammation induced by TGRL lipolysis products may contribute to pathophysiological processes of vascular dementia.
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Affiliation(s)
- Tun Nyunt
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA, 95616, USA
| | - Monica Britton
- Genome Center and Bioinformatics Core Facility, University of California, Davis, CA, 95616, USA
| | - Kwanjeera Wanichthanarak
- West Coast Metabolomics Center, Genome Center, University of California Davis, Davis, CA, USA; Department of Biochemistry and Siriraj Metabolomics and Phenomics Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Madhu Budamagunta
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Davis, CA, 95616, USA
| | - John C Voss
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Davis, CA, 95616, USA
| | - Dennis W Wilson
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, 95616, USA
| | - John C Rutledge
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA, 95616, USA
| | - Hnin H Aung
- Division of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, University of California, Davis, Davis, CA, 95616, USA.
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22
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Late Brain Involvement after Neonatal Immune Activation. BIOMED RESEARCH INTERNATIONAL 2019; 2019:9573248. [PMID: 31467920 PMCID: PMC6699266 DOI: 10.1155/2019/9573248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/07/2019] [Indexed: 01/18/2023]
Abstract
The neonatal immune system is still immature, which makes it more susceptible to the infectious agents. Neonatal immune activation is associated with increased permeability of the blood-brain barrier, causing an inflammatory cascade in the CNS and altering behavioral and neurochemical parameters. One of the hypotheses that has been studied is that neuroinflammation may be involved in neurodegenerative processes, such as Alzheimer's disease (AD). We evaluate visuospatial memory, cytokines levels, and the expression of tau and GSK-3β proteins in hippocampus and cortex of animals exposed to neonatal endotoxemia. C57BL/6 mice aging two days received a single injection of subcutaneous lipopolysaccharide (LPS). At 60,120, and 180 days of age, visual-spatial memory was evaluated and the hippocampus and cortex were dissected to evaluate the cytokines levels and expression of tau and GSK-3β proteins. The animals exposed to LPS in the neonatal period present with visuospatial memory impairment at 120 and 180 days of age. Here there was an increase of TNF-α and IL-1β levels in the hippocampus and cortex only at 60 days of age. Here there was an increase in the expression of GSK-3β in hippocampus of the animals at 60, 120, and 180 days of age. In the cortex, this increase occurred in the 120 and 180 days of age. Tau protein expression was high in hippocampus and cortex at 120 days of age and in hippocampus at 180 days of age. The data observed show that neonatal immune activation may be associated with visuospatial memory impairment, neuroinflammation, and increased expression of GSK-3β and Tau proteins in the long term.
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23
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Friedman BA, Srinivasan K, Ayalon G, Meilandt WJ, Lin H, Huntley MA, Cao Y, Lee SH, Haddick PCG, Ngu H, Modrusan Z, Larson JL, Kaminker JS, van der Brug MP, Hansen DV. Diverse Brain Myeloid Expression Profiles Reveal Distinct Microglial Activation States and Aspects of Alzheimer's Disease Not Evident in Mouse Models. Cell Rep 2019; 22:832-847. [PMID: 29346778 DOI: 10.1016/j.celrep.2017.12.066] [Citation(s) in RCA: 394] [Impact Index Per Article: 78.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 10/03/2017] [Accepted: 12/20/2017] [Indexed: 10/18/2022] Open
Abstract
Microglia, the CNS-resident immune cells, play important roles in disease, but the spectrum of their possible activation states is not well understood. We derived co-regulated gene modules from transcriptional profiles of CNS myeloid cells of diverse mouse models, including new tauopathy model datasets. Using these modules to interpret single-cell data from an Alzheimer's disease (AD) model, we identified microglial subsets-distinct from previously reported "disease-associated microglia"-expressing interferon-related or proliferation modules. We then analyzed whole-tissue RNA profiles from human neurodegenerative diseases, including a new AD dataset. Correcting for altered cellular composition of AD tissue, we observed elevated expression of the neurodegeneration-related modules, but also modules not implicated using expression profiles from mouse models alone. We provide a searchable, interactive database for exploring gene expression in all these datasets (http://research-pub.gene.com/BrainMyeloidLandscape). Understanding the dimensions of CNS myeloid cell activation in human disease may reveal opportunities for therapeutic intervention.
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Affiliation(s)
- Brad A Friedman
- Department of Bioinformatics and Computational Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Karpagam Srinivasan
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Gai Ayalon
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - William J Meilandt
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Han Lin
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Melanie A Huntley
- Department of Bioinformatics and Computational Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Yi Cao
- Department of Bioinformatics and Computational Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Seung-Hye Lee
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Patrick C G Haddick
- Department of Biomarker Discovery OMNI, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Hai Ngu
- Department of Pathology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Zora Modrusan
- Department of Molecular Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Jessica L Larson
- Department of Bioinformatics and Computational Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Joshua S Kaminker
- Department of Bioinformatics and Computational Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA; Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Marcel P van der Brug
- Department of Biomarker Discovery OMNI, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - David V Hansen
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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24
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Lipopolysaccharide-Induced Neuroinflammation as a Bridge to Understand Neurodegeneration. Int J Mol Sci 2019; 20:ijms20092293. [PMID: 31075861 PMCID: PMC6539529 DOI: 10.3390/ijms20092293] [Citation(s) in RCA: 253] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/03/2019] [Accepted: 05/05/2019] [Indexed: 12/19/2022] Open
Abstract
A large body of experimental evidence suggests that neuroinflammation is a key pathological event triggering and perpetuating the neurodegenerative process associated with many neurological diseases. Therefore, different stimuli, such as lipopolysaccharide (LPS), are used to model neuroinflammation associated with neurodegeneration. By acting at its receptors, LPS activates various intracellular molecules, which alter the expression of a plethora of inflammatory mediators. These factors, in turn, initiate or contribute to the development of neurodegenerative processes. Therefore, LPS is an important tool for the study of neuroinflammation associated with neurodegenerative diseases. However, the serotype, route of administration, and number of injections of this toxin induce varied pathological responses. Thus, here, we review the use of LPS in various models of neurodegeneration as well as discuss the neuroinflammatory mechanisms induced by this toxin that could underpin the pathological events linked to the neurodegenerative process.
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25
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Komanduri M, Gondalia S, Scholey A, Stough C. The microbiome and cognitive aging: a review of mechanisms. Psychopharmacology (Berl) 2019; 236:1559-1571. [PMID: 31055629 DOI: 10.1007/s00213-019-05231-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/18/2019] [Indexed: 12/26/2022]
Abstract
Gut microbiota plays an intrinsic role in communication between the gut and the brain and is capable of influencing the host brain by producing neurotransmitters and neurotrophins, the modulation of inflammatory processes amongst other key mechanisms. Increased age is also associated with changes in these key biological processes and impairments in a range of cognitive processes. We hypothesise several mechanisms in which gut microbiota may modulate changes in cognitive function with age. In this review, we discuss issues related to the measurement of cognition in the elderly and in particular outline a standardised model of cognition that could be utilised to better understand cognitive outcomes in future studies examining the relationship between gut microbiota and cognition in the elderly. We then review biological processes such as oxidative stress and inflammation which are related to cognitive changes with age and which are also influenced by our gut microbiota. Finally, we outline other potential mechanisms by which the gut microbiota may influence cognition.
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Affiliation(s)
- Mrudhula Komanduri
- Centre for Human Psychopharmacology, Swinburne University of Technology, PO Box 218, Hawthorn, Melbourne, Victoria, Australia
| | - Shakuntla Gondalia
- Centre for Human Psychopharmacology, Swinburne University of Technology, PO Box 218, Hawthorn, Melbourne, Victoria, Australia
| | - Andrew Scholey
- Centre for Human Psychopharmacology, Swinburne University of Technology, PO Box 218, Hawthorn, Melbourne, Victoria, Australia
| | - Con Stough
- Centre for Human Psychopharmacology, Swinburne University of Technology, PO Box 218, Hawthorn, Melbourne, Victoria, Australia.
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26
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Systemic LPS-induced Aβ-solubilization and clearance in AβPP-transgenic mice is diminished by heparanase overexpression. Sci Rep 2019; 9:4600. [PMID: 30872722 PMCID: PMC6418119 DOI: 10.1038/s41598-019-40999-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/26/2019] [Indexed: 12/12/2022] Open
Abstract
Amyloid-β (Aβ) is the main constituent of amyloid deposits in Alzheimer’s disease (AD). The neuropathology is associated with neuroinflammation. Here, we investigated effects of systemic lipopolysaccharide (LPS)-treatment on neuroinflammation and Aβ deposition in AβPP-mice and double-transgenic mice with brain expression of AβPP and heparanase, an enzyme that degrades HS and generates an attenuated LPS-response. At 13 months of age, the mice received a single intraperitoneal injection of 50 µg LPS or vehicle, and were sacrificed 1.5 months thereafter. Aβ in the brain was analyzed histologically and biochemically after sequential detergent extraction. Neuroinflammation was assessed by CD45 immunostaining and mesoscale cytokine/chemokine ELISA. In single-transgenic mice, LPS-treatment reduced total Aβ deposition and increased Tween-soluble Aβ. This was associated with a reduced CXCL1, IL-1β, TNF-α-level and microgliosis, which correlated with amyloid deposition and total Aβ. In contrast, LPS did not change Aβ accumulation or inflammation marker in the double-transgenic mice. Our findings suggest that a single pro-inflammatory LPS-stimulus, if given sufficient time to act, triggers Aβ-clearance in AβPP-transgenic mouse brain. The effects depend on HS and heparanase.
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27
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Imbalance of Microglial TLR4/TREM2 in LPS-Treated APP/PS1 Transgenic Mice: A Potential Link Between Alzheimer's Disease and Systemic Inflammation. Neurochem Res 2019; 44:1138-1151. [PMID: 30756214 DOI: 10.1007/s11064-019-02748-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 02/01/2019] [Accepted: 02/01/2019] [Indexed: 02/07/2023]
Abstract
Clinically, superimposed systemic inflammation generally has significant deleterious effects on the Alzheimer's disease (AD) progression. However, the related molecular mechanisms remain poorly understood. Microglial toll-like receptor 4 (TLR4) and triggering receptor expressed on myeloid cells 2 (TREM2) are two key regulators of inflammation that may play an essential role in this complex pathophysiological process. In this study, intraperitoneal injection of lipopolysaccharide (LPS) into APP/PS1 transgenic AD model was used to mimic systemic inflammation in the development of AD. Initial results from the cortex showed that compared with wild-type mice, APP/PS1 mice exhibited elevated gene and protein expression levels of both TLR4 and TREM2 with different degree. Interestingly, after LPS treatment, TLR4 expression was persistently up-regulated, while TREM2 expression was significantly down-regulated in APP/PS1 mice, suggesting that the negative regulatory effect of TREM2 on inflammation might be suppressed by LPS-induced hyperactive TLR4. This imbalance of TLR4/TREM2 contributed to microglial over-activation, followed by increased neuronal apoptosis in the cortex of APP/PS1 mice; these changes did not alter the expression level of Aβ1-42. Similar alterations were observed in our in vitro experiment with β-amyloid1-42 (Aβ1-42)-treated N9 microglia. Further, Morris water maze (MWM) testing data indicated that LPS administration acutely aggravated cognitive impairment in APP/PS1 mice, suggesting that the addition of systemic inflammation can potentially accelerate the progression of AD. Collectively, we conclude that an imbalance of TLR4/TREM2 may be a potential link between AD and systemic inflammation. TREM2 can serve as a potential therapeutic target for treating systemic inflammation in AD progression.
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28
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Polis B, Srikanth KD, Gurevich V, Gil-Henn H, Samson AO. L-Norvaline, a new therapeutic agent against Alzheimer's disease. Neural Regen Res 2019; 14:1562-1572. [PMID: 31089055 PMCID: PMC6557086 DOI: 10.4103/1673-5374.255980] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Growing evidence highlights the role of arginase activity in the manifestation of Alzheimer’s disease (AD). Upregulation of arginase was shown to contribute to neurodegeneration. Regulation of arginase activity appears to be a promising approach for interfering with the pathogenesis of AD. Therefore, the enzyme represents a novel therapeutic target. In this study, we administered an arginase inhibitor, L-norvaline (250 mg/L), for 2.5 months to a triple-transgenic model (3×Tg-AD) harboring PS1M146V, APPSwe, and tauP301L transgenes. Then, the neuroprotective effects of L-norvaline were evaluated using immunohistochemistry, proteomics, and quantitative polymerase chain reaction assays. Finally, we identified the biological pathways activated by the treatment. Remarkably, L-norvaline treatment reverses the cognitive decline in AD mice. The treatment is neuroprotective as indicated by reduced beta-amyloidosis, alleviated microgliosis, and reduced tumor necrosis factor transcription levels. Moreover, elevated levels of neuroplasticity related postsynaptic density protein 95 were detected in the hippocampi of mice treated with L-norvaline. Furthermore, we disclosed several biological pathways, which were involved in cell survival and neuroplasticity and were activated by the treatment. Through these modes of action, L-norvaline has the potential to improve the symptoms of AD and even interferes with its pathogenesis. As such, L-norvaline is a promising neuroprotective molecule that might be tailored for the treatment of a range of neurodegenerative disorders. The study was approved by the Bar-Ilan University Animal Care and Use Committee (approval No. 82-10-2017) on October 1, 2017.
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Affiliation(s)
- Baruh Polis
- Drug Discovery Laboratory, The Azrieli Faculty of Medicine; Laboratory of Cell Migration and Invasion, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Kolluru D Srikanth
- Laboratory of Cell Migration and Invasion, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Vyacheslav Gurevich
- Laboratory of Cancer Personalized Medicine and Diagnostic Genomics, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Hava Gil-Henn
- Laboratory of Cell Migration and Invasion, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Abraham O Samson
- Drug Discovery Laboratory, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
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29
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Hooshmandi E, Ghasemi R, Iloun P, Moosavi M. The neuroprotective effect of agmatine against amyloid β-induced apoptosis in primary cultured hippocampal cells involving ERK, Akt/GSK-3β, and TNF-α. Mol Biol Rep 2018; 46:489-496. [PMID: 30474774 DOI: 10.1007/s11033-018-4501-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 11/13/2018] [Indexed: 12/29/2022]
Abstract
β-Amyloid peptide (Aβ), the major element of senile plaques in Alzheimer's disease (AD), has been found to accumulate in brain regions critical for memory and cognition. Deposits of Aβ trigger neurotoxic events which lead to neural apoptotic death. The present study examined whether agmatine, an endogenous polyamine formed by the decarboxylation of L-arginine, possesses a neuroprotective effect against Aβ-induced toxicity. Primary rat hippocampal cells extracted from the brains of 18-19-day-old embryos were exposed to 10 µM of Aβ (25-35) in the absence or presence of agmatine at 150 or 250 µM. Additionally, the involvement of Akt (Protein Kinae B), GSK-3β (glycogen synthase kinase 3-β), ERK (Extracellular Signal-Regulated Kinase) and TNF-α (Tumor necrosis factor-α) in the agmatine protection against Aβ-induced neurotoxicity was investigated. Agmatine significantly prevented the effect of Aβ exposure on cell viability and caspase-3 assays. Furthermore, agmatine considerably restored Aβ-induced decline of phospho-Akt and phospho-GSK and blocked Aβ-induced increase of phospho-ERK and TNF-alpha. Taken together, these findings might shed light on the protective effect of agmatine as a potential therapeutic agent for AD.
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Affiliation(s)
- Etrat Hooshmandi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Clinical Neurology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Rasoul Ghasemi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parisa Iloun
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Moosavi
- Shiraz Nuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
- Nanobiology and Nanomedicine Research Centre, Shiraz University of Medical sciences, Shiraz, Iran.
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30
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Thygesen C, Ilkjær L, Kempf SJ, Hemdrup AL, von Linstow CU, Babcock AA, Darvesh S, Larsen MR, Finsen B. Diverse Protein Profiles in CNS Myeloid Cells and CNS Tissue From Lipopolysaccharide- and Vehicle-Injected APP SWE/PS1 ΔE9 Transgenic Mice Implicate Cathepsin Z in Alzheimer's Disease. Front Cell Neurosci 2018; 12:397. [PMID: 30459560 PMCID: PMC6232379 DOI: 10.3389/fncel.2018.00397] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 10/15/2018] [Indexed: 12/20/2022] Open
Abstract
Neuroinflammation, characterized by chronic activation of the myeloid-derived microglia, is a hallmark of Alzheimer’s disease (AD). Systemic inflammation, typically resulting from infection, has been linked to the progression of AD due to exacerbation of the chronic microglial reaction. However, the mechanism and the consequences of this exacerbation are largely unknown. Here, we mimicked systemic inflammation in AD with weekly intraperitoneal (i.p.) injections of APPSWE/PS1ΔE9 transgenic mice with E. coli lipopolysaccharide (LPS) from 9 to 12 months of age, corresponding to the period with the steepest increase in amyloid pathology. We found that the repeated LPS injections ameliorated amyloid pathology in the neocortex while increasing the neuroinflammatory reaction. To elucidate mechanisms, we analyzed the proteome of the hippocampus from the same mice as well as in unique samples of CNS myeloid cells. The repeated LPS injections stimulated protein pathways of the complement system, retinoid receptor activation and oxidative stress. CNS myeloid cells from transgenic mice showed enrichment in pathways of amyloid-beta clearance and elevated levels of the lysosomal protease cathepsin Z, as well as amyloid precursor protein, apolipoprotein E and clusterin. These proteins were found elevated in the proteome of both LPS and vehicle injected transgenics, and co-localized to CD11b+ microglia in transgenic mice and in primary murine microglia. Additionally, cathepsin Z, amyloid precursor protein, and apolipoprotein E appeared associated with amyloid plaques in neocortex of AD cases. Interestingly, cathepsin Z was expressed in microglial-like cells and co-localized to CD68+ microglial lysosomes in AD cases, and it was expressed in perivascular cells in AD and control cases. Taken together, our results implicate systemic LPS administration in ameliorating amyloid pathology in early-to-mid stage disease in the APPSWE/PS1ΔE9 mouse and attract attention to the potential disease involvement of cathepsin Z expressed in CNS myeloid cells in AD.
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Affiliation(s)
- Camilla Thygesen
- Department of Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.,Brain Research - Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Laura Ilkjær
- Department of Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Stefan J Kempf
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Anne Louise Hemdrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | | | - Alicia A Babcock
- Department of Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Sultan Darvesh
- Department of Medicine (Neurology and Geriatric Medicine) - Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada.,Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, NS, Canada
| | - Martin R Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Bente Finsen
- Department of Neurobiology, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Brain Research - Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
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31
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Wijesekara N, Gonçalves RA, De Felice FG, Fraser PE. Impaired peripheral glucose homeostasis and Alzheimer's disease. Neuropharmacology 2017; 136:172-181. [PMID: 29169962 DOI: 10.1016/j.neuropharm.2017.11.027] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 11/12/2017] [Accepted: 11/16/2017] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is the most common type of dementia. Recent studies suggest that metabolic disturbances, particularly type 2 diabetes (T2D) increase the risk of cognitive decline and AD. AD is also a risk factor for T2D, and a growing body of evidence indicates that these diseases are connected both at clinical and molecular levels. In T2D, peripheral insulin resistance, hyperglycemia and eventually insulin deficiency develops, leading to an overall decline in tissue health. More recently, brain insulin resistance has been shown to be a key feature of AD that is linked to neuronal dysfunction and cognitive impairment. Furthermore, both AD and T2D are amyloidogenic diseases, with abnormal aggregation of amyloid-β peptide (Aβ) and islet amyloid polypeptide (IAPP) respectively contributing to cellular death and disease pathogenesis. Emerging data suggests that Aβ may have peripheral effects including its co-deposition in the pancreas. In this review, we discuss how peripheral effects of Aβ and metabolic disturbances may impact AD pathogenesis. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'
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Affiliation(s)
- Nadeeja Wijesekara
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Avenue, Toronto, Ontario, M5T 2S8, Canada.
| | - Rafaella Araujo Gonçalves
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Avenue, Toronto, Ontario, M5T 2S8, Canada; Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Fernanda G De Felice
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Centre for Neuroscience Studies, Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Paul E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Avenue, Toronto, Ontario, M5T 2S8, Canada; Department of Medical Biophysics, University of Toronto, Canada.
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32
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Santos LE, Ferreira ST. Crosstalk between endoplasmic reticulum stress and brain inflammation in Alzheimer's disease. Neuropharmacology 2017; 136:350-360. [PMID: 29129774 DOI: 10.1016/j.neuropharm.2017.11.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 11/08/2017] [Indexed: 02/07/2023]
Abstract
While most often noted for its cognitive symptoms, Alzheimer's disease (AD) is, at its core, a disease of protein misfolding/aggregation, with an intriguing inflammatory component. Defective clearance and/or abnormal production of the amyloid-β peptide (Aβ), and its ensuing accumulation and aggregation, underlie two hallmark features of AD: brain accumulation of insoluble protein deposits known as amyloid or senile plaques, and buildup of soluble Aβ oligomers (AβOs), diffusible toxins linked to synapse dysfunction and memory impairment. In neurons, as in typical eukaryotic cells, the endoplasmic reticulum (ER) serves as a main compartment for the folding, maturation, trafficking and quality control of newly synthesized proteins. The ER lumen, a calcium-rich, oxidizing environment, provides favorable conditions for these physiological functions to occur. These conditions, however, also favor protein aggregation. Several stressors, including metabolic/nutrient stress and certain pathologies, may upset the ER homeostasis, e.g., by affecting calcium levels or by causing the accumulation of unfolded or misfolded proteins. Whatever the underlying cause, the result is what is commonly known as "ER stress". This, in turn, triggers a conserved cellular response mechanism known as the "unfolded protein response" (UPR). The UPR comprises three pathways involving transcriptional or translational regulators aimed at normalizing ER function, and each of them results in pro-inflammatory signaling. A positive feedback loop exists between ER stress and inflammation, with clear implications for neurodegeneration and AD. Here, we explore recent findings on the role of ER stress and the UPR in inflammatory processes leading to synapse failure and memory impairment in AD. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'
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Affiliation(s)
- Luis E Santos
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21944-590, Brazil
| | - Sergio T Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21944-590, Brazil; Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21944-590, Brazil.
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Fahrenhold M, Rakic S, Classey J, Brayne C, Ince PG, Nicoll JAR, Boche D. TREM2 expression in the human brain: a marker of monocyte recruitment? Brain Pathol 2017; 28:595-602. [PMID: 28987033 PMCID: PMC6221091 DOI: 10.1111/bpa.12564] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 10/02/2017] [Indexed: 01/04/2023] Open
Abstract
Mutation in the triggering receptor expressed on myeloid cells (TREM) 2 gene has been identified as a risk factor for several neurodegenerative diseases including Alzheimer's disease (AD). Experimental studies using animal models of AD have highlighted a number of functions associated with TREM2 and its expression by microglial cells. It has therefore been assumed that this is also the case in humans. However, there is very limited information concerning the cellular expression of TREM2 in the human brain. As part of investigations of microglia using post‐mortem resources provided by the Medical Research Council Cognitive Function and Ageing Studies (MRC‐CFAS), we immunostained the cerebral cortex of 299 participants for TREM2 using the Sigma antibody HPA010917 and compared with the macrophage/microglial markers Iba1 and CD68. As expected, Iba1 and CD68 labeled microglia and perivascular macrophages. However, in most cases (284/299), the TREM2 antibody labelled monocytes within vascular lumens, but not microglia or perivascular macrophages. In contrast, in 5 out of 6 cases with acute infarcts, TREM2 immunoreaction identified cells within the brain parenchyma interpreted as recruited monocytes. Six cases with old infarcts contained phagocytic foamy macrophages which were CD68‐positive but TREM2 negative. Our observations, using the HPA010917 anti‐TREM2 antibody, suggest that TREM2 is not expressed by microglia but instead seems to be a marker of recruited monocytes in the human brain. This finding has implications with regards to the role of TREM2 as a risk factor, emphasizing the importance of systemic immune responses in the development and progression of Alzheimer's disease.
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Affiliation(s)
- Marie Fahrenhold
- Clinical Neurosciences, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
| | - Sonja Rakic
- Clinical Neurosciences, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
| | - John Classey
- Clinical Neurosciences, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
| | - Carol Brayne
- Cambridge Institute of Public Health, Department of Public Health and Primary Care, University of Cambridge, Cambridge, CB1 8RN, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, Sheffield University, Sheffield, S10 2HQ, UK
| | - James A R Nicoll
- Clinical Neurosciences, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK.,Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, Southampton SO16 6YD, UK
| | - Delphine Boche
- Clinical Neurosciences, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
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Teixeira FB, Saito MT, Matheus FC, Prediger RD, Yamada ES, Maia CSF, Lima RR. Periodontitis and Alzheimer's Disease: A Possible Comorbidity between Oral Chronic Inflammatory Condition and Neuroinflammation. Front Aging Neurosci 2017; 9:327. [PMID: 29085294 PMCID: PMC5649154 DOI: 10.3389/fnagi.2017.00327] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 12/31/2022] Open
Abstract
Periodontitis is an oral chronic infection/inflammatory condition, identified as a source of mediators of inflammation into the blood circulation, which may contribute to exacerbate several diseases. There is increasing evidence that inflammation plays a key role in the pathophysiology of Alzheimer’s disease (AD). Although inflammation is present in both diseases, the exact mechanisms and crosslinks between periodontitis and AD are poorly understood. Therefore, this article aims to review possible comorbidity between periodontitis and AD. Here, the authors discuss the inflammatory aspects of periodontitis, how this oral condition produces a systemic inflammation and, finally, the contribution of this systemic inflammation for worsening neuroinflammation in the progression of AD.
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Affiliation(s)
- Francisco B Teixeira
- Institute of Biological Science, Federal University of Pará, Belém, Brazil.,College of Medicine, Federal University of Pará, Altamira, Brazil
| | - Miki T Saito
- Dental School, Brazil-Amazon Integrated Faculty, Belém, Brazil
| | - Filipe C Matheus
- Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Rui D Prediger
- Department of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Elizabeth S Yamada
- Institute of Biological Science, Federal University of Pará, Belém, Brazil
| | | | - Rafael R Lima
- Institute of Biological Science, Federal University of Pará, Belém, Brazil
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35
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Murta V, Ferrari C. Peripheral Inflammation and Demyelinating Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 949:263-285. [PMID: 27714694 DOI: 10.1007/978-3-319-40764-7_13] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In recent decades, several neurodegenerative diseases have been shown to be exacerbated by systemic inflammatory processes. There is a wide range of literature that demonstrates a clear but complex relationship between the central nervous system (CNS) and the immunological system, both under naïve or pathological conditions. In diseased brains, peripheral inflammation can transform "primed" microglia into an "active" state, which can trigger stronger pathological responses. Demyelinating diseases are a group of neurodegenerative diseases characterized by inflammatory lesions associated with demyelination, which in turn induces axonal damage, neurodegeneration, and progressive loss of function. Among them, the most important are multiple sclerosis (MS) and neuromyelitis optica (NMO). In this review, we will analyze the effect of specific peripheral inflammatory stimuli in the progression of demyelinating diseases and discuss their animal models. In most cases, peripheral immune stimuli are exacerbating.
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Affiliation(s)
- Verónica Murta
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencias, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Carina Ferrari
- Instituto de Ciencias Básicas y Medicina Experimental, Instituto Universitario del Hospital Italiano, Buenos Aires, Argentina.
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Yi B, Sahn JJ, Ardestani PM, Evans AK, Scott LL, Chan JZ, Iyer S, Crisp A, Zuniga G, Pierce JT, Martin SF, Shamloo M. Small molecule modulator of sigma 2 receptor is neuroprotective and reduces cognitive deficits and neuroinflammation in experimental models of Alzheimer's disease. J Neurochem 2017; 140:561-575. [PMID: 27926996 DOI: 10.1111/jnc.13917] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/23/2016] [Accepted: 12/01/2016] [Indexed: 12/29/2022]
Abstract
Accumulating evidence suggests that modulating the sigma 2 receptor (Sig2R) can provide beneficial effects for neurodegenerative diseases. Herein, we report the identification of a novel class of Sig2R ligands and their cellular and in vivo activity in experimental models of Alzheimer's disease (AD). We report that SAS-0132 and DKR-1051, selective ligands of Sig2R, modulate intracellular Ca2+ levels in human SK-N-SH neuroblastoma cells. The Sig2R ligands SAS-0132 and JVW-1009 are neuroprotective in a C. elegans model of amyloid precursor protein-mediated neurodegeneration. Since this neuroprotective effect is replicated by genetic knockdown and knockout of vem-1, the ortholog of progesterone receptor membrane component-1 (PGRMC1), these results suggest that Sig2R ligands modulate a PGRMC1-related pathway. Last, we demonstrate that SAS-0132 improves cognitive performance both in the Thy-1 hAPPLond/Swe+ transgenic mouse model of AD and in healthy wild-type mice. These results demonstrate that Sig2R is a promising therapeutic target for neurocognitive disorders including AD.
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Affiliation(s)
- Bitna Yi
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - James J Sahn
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Pooneh Memar Ardestani
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - Andrew K Evans
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - Luisa L Scott
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Jessica Z Chan
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Sangeetha Iyer
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Ashley Crisp
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Gabriella Zuniga
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Jonathan T Pierce
- Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, Center for Learning and Memory, Center for Brain, Behavior and Evolution and Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Stephen F Martin
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Mehrdad Shamloo
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
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Obst J, Simon E, Mancuso R, Gomez-Nicola D. The Role of Microglia in Prion Diseases: A Paradigm of Functional Diversity. Front Aging Neurosci 2017; 9:207. [PMID: 28690540 PMCID: PMC5481309 DOI: 10.3389/fnagi.2017.00207] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 06/09/2017] [Indexed: 12/26/2022] Open
Abstract
Inflammation is a major component of neurodegenerative diseases. Microglia are the innate immune cells in the central nervous system (CNS). In the healthy brain, microglia contribute to tissue homeostasis and regulation of synaptic plasticity. Under disease conditions, they play a key role in the development and maintenance of the neuroinflammatory response, by showing enhanced proliferation and activation. Prion diseases are progressive chronic neurodegenerative disorders associated with the accumulation of the scrapie prion protein PrPSc, a misfolded conformer of the cellular prion protein PrPC. This review article provides the current knowledge on the role of microglia in the pathogenesis of prion disease. A large body of evidence shows that microglia can trigger neurotoxic pathways contributing to progressive degeneration. Yet, microglia are also crucial for controlling inflammatory, repair and regenerative processes. This dual role of microglia is regulated by multiple pathways and evidences the ability of these cells to polarize into distinct phenotypes with characteristic functions. The awareness that the neuroinflammatory response is inextricably involved in producing tissue damage as well as repair in neurodegenerative disorders, opens new perspectives for the modulation of the immune system. A better understanding of this complex process will be essential for developing effective therapies for neurodegenerative diseases, in order to improve the quality of life of patients and mitigating the personal, economic and social consequences derived from these diseases.
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Affiliation(s)
- Juliane Obst
- Biological Sciences, University of Southampton, Southampton General HospitalSouthampton, United Kingdom
| | - Emilie Simon
- Biological Sciences, University of Southampton, Southampton General HospitalSouthampton, United Kingdom
| | - Renzo Mancuso
- Biological Sciences, University of Southampton, Southampton General HospitalSouthampton, United Kingdom
| | - Diego Gomez-Nicola
- Biological Sciences, University of Southampton, Southampton General HospitalSouthampton, United Kingdom
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38
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Chang R, Yee KL, Sumbria RK. Tumor necrosis factor α Inhibition for Alzheimer's Disease. J Cent Nerv Syst Dis 2017; 9:1179573517709278. [PMID: 28579870 PMCID: PMC5436834 DOI: 10.1177/1179573517709278] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 03/28/2017] [Indexed: 12/11/2022] Open
Abstract
Tumor necrosis factor α (TNF-α) plays a central role in the pathophysiology of Alzheimer's disease (AD). Food and Drug Administration-approved biologic TNF-α inhibitors are thus a potential treatment for AD, but they do not cross the blood-brain barrier. In this short review, we discuss the involvement of TNF-α in AD, challenges associated with the development of existing biologic TNF-α inhibitors for AD, and potential therapeutic strategies for targeting TNF-α for AD therapy.
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Affiliation(s)
- Rudy Chang
- Department of Biopharmaceutical Sciences, School of Pharmacy, Keck Graduate Institute, Claremont, CA, USA
| | - Kei-Lwun Yee
- Department of Biopharmaceutical Sciences, School of Pharmacy, Keck Graduate Institute, Claremont, CA, USA
| | - Rachita K Sumbria
- Department of Biopharmaceutical Sciences, School of Pharmacy, Keck Graduate Institute, Claremont, CA, USA
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39
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Schreuder L, Eggen BJ, Biber K, Schoemaker RG, Laman JD, de Rooij SE. Pathophysiological and behavioral effects of systemic inflammation in aged and diseased rodents with relevance to delirium: A systematic review. Brain Behav Immun 2017; 62:362-381. [PMID: 28088641 DOI: 10.1016/j.bbi.2017.01.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 12/26/2016] [Accepted: 01/10/2017] [Indexed: 01/20/2023] Open
Abstract
Delirium is a frequent outcome for aged and demented patients that suffer a systemic inflammatory insult. Animal models that reconstruct these etiological processes have potential to provide a better understanding of the pathophysiology of delirium. Therefore, we systematically reviewed animal studies in which systemic inflammation was superimposed on aged or diseased animal models. In total, 77 studies were identified. Aged animals were challenged with a bacterial endotoxin in 29 studies, 25 studies superimposed surgery on aged animals, and in 6 studies a bacterial infection, Escherichia coli (E. coli), was used. Diseased animals were challenged with a bacterial endotoxin in 15 studies, two studies examined effects of the cytokine IL-1β, and one study used polyinosinic:polycytidilic acid (poly I:C). This systematic review analyzed the impact of systemic inflammation on the production of inflammatory and neurotoxic mediators in peripheral blood, cerebrospinal fluid (CSF), and on the central nervous system (CNS). Moreover, concomitant behavioral and cognitive symptoms were also evaluated. Finally, outcomes of behavioral and cognitive tests from animal studies were compared to features and symptoms present in delirious patients.
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Affiliation(s)
- Leroy Schreuder
- University of Groningen, University Medical Center Groningen, University Center for Geriatric Medicine, Groningen, The Netherlands.
| | - B J Eggen
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - Knut Biber
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Psychiatry and Psychotherapy, Section of Molecular Psychiatry, University of Freiburg, Freiburg, Germany.
| | - Regien G Schoemaker
- Department of Neurobiology, GELIFES, University of Groningen, Groningen, The Netherlands.
| | - Jon D Laman
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - Sophia E de Rooij
- University of Groningen, University Medical Center Groningen, University Center for Geriatric Medicine, Groningen, The Netherlands.
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40
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Sharma N, Sharma S, Nehru B. Curcumin protects dopaminergic neurons against inflammation-mediated damage and improves motor dysfunction induced by single intranigral lipopolysaccharide injection. Inflammopharmacology 2017; 25:351-368. [PMID: 28409389 DOI: 10.1007/s10787-017-0346-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 03/31/2017] [Indexed: 01/08/2023]
Abstract
Various studies have indicated a lower incidence and prevalence of neurological conditions in people consuming curcumin. The ability of curcumin to target multiple cascades, simultaneously, could be held responsible for its neuroprotective effects. The present study was designed to investigate the potential of curcumin in minimizing microglia-mediated damage in lipopolysaccharide (LPS) induced model of PD. Altered microglial functions and increased inflammatory profile of the CNS have severe behavioral consequences. In the current investigation, a single injection of LPS (5 ug/5 µl PBS) was injected into the substantia nigra (SN) of rats, and curcumin [40 mg/kg b.wt (i.p.)] was administered daily for a period of 21 days. LPS triggered an inflammatory response characterized by glial activation [Iba-1 and glial fibrillary acidic protein (GFAP)] and pro-inflammatory cytokine production (TNF-α and IL-1β) leading to extensive dopaminergic loss and behavioral abnormality in rats. The behavioral observations, biochemical markers, quantification of dopamine and its metabolites (DOPAC and HVA) using HPLC followed by IHC of tyrosine hydroxylase (TH) were evaluated after 21 days of LPS injection. Curcumin supplementation prevented dopaminergic degeneration in LPS-treated animals by normalizing the altered levels of biomarkers. Also, a significant improvement in TH levels as well as behavioral parameters (actophotometer, rotarod, beam walking and grid walking tests) were seen in LPS injected rats. Curcumin shielded the dopaminergic neurons against LPS-induced inflammatory response, which was associated with suppression of glial activation (microglia and astrocytes) and transcription factor NF-κB as depicted from RT-PCR and EMSA assay. Curcumin also suppressed microglial NADPH oxidase activation as observed from NADPH oxidase activity. The results suggested that one of the important mechanisms by which curcumin mediates its protective effects in the LPS-induced PD model is by inhibiting glial activation. Therefore, curcumin could be a potential therapeutic agent for inflammation-driven neurodegenerative disorders like PD, and its neuroprotective role should be explored further.
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Affiliation(s)
- Neha Sharma
- Department of Biophysics, Panjab University, Chandigarh, 160014, India
| | - Sheetal Sharma
- Department of Biophysics, Panjab University, Chandigarh, 160014, India
| | - Bimla Nehru
- Department of Biophysics, Panjab University, Chandigarh, 160014, India.
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Vallée A, Lecarpentier Y. Alzheimer Disease: Crosstalk between the Canonical Wnt/Beta-Catenin Pathway and PPARs Alpha and Gamma. Front Neurosci 2016; 10:459. [PMID: 27807401 PMCID: PMC5069291 DOI: 10.3389/fnins.2016.00459] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 09/22/2016] [Indexed: 12/25/2022] Open
Abstract
The molecular mechanisms underlying the pathophysiology of Alzheimer's disease (AD) are still not fully understood. In AD, Wnt/beta-catenin signaling has been shown to be downregulated while the peroxisome proliferator-activated receptor (PPAR) gamma (mARN and protein) is upregulated. Certain neurodegenerative diseases share the same Wnt/beta-catenin/PPAR gamma profile, such as bipolar disorder and schizophrenia. Conversely, other NDs share an opposite profile, such as amyotrophic lateral sclerosis, Parkinson's disease, Huntington's disease, multiple sclerosis, and Friedreich's ataxia. AD is characterized by the deposition of extracellular Abeta plaques and the formation of intracellular neurofibrillary tangles in the central nervous system (CNS). Activation of Wnt signaling or inhibition of both glycogen synthase kinase-3beta and Dickkopf 1, two key negative regulators of the canonical Wnt pathway, are able to protect against Abeta neurotoxicity and to ameliorate cognitive performance in AD patients. Although PPAR gamma is upregulated in AD patients, and despite the fact that it has been shown that the PPAR gamma and Wnt/beta catenin pathway systems work in an opposite manner, PPAR gamma agonists diminish learning and memory deficits, decrease Abeta activation of microglia, and prevent hippocampal and cortical neurons from dying. These beneficial effects observed in AD transgenic mice and patients might be partially due to the anti-inflammatory properties of PPAR gamma agonists. Moreover, activation of PPAR alpha upregulates transcription of the alpha-secretase gene and represents a new therapeutic treatment for AD. This review focuses largely on the behavior of two opposing pathways in AD, namely Wnt/beta-catenin signaling and PPAR gamma. It is hoped that this approach may help to develop novel AD therapeutic strategies integrating PPAR alpha signaling.
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Affiliation(s)
- Alexandre Vallée
- CHU Amiens Picardie, Université Picardie Jules VerneAmiens, France
- Experimental and Clinical Neurosciences Laboratory, INSERM U1084, University of PoitiersPoitiers, France
- AP-HP, Epidemiology and Clinical Research Department, University Hospital Bichat-Claude BernardParis, France
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Astrocytes Are Primed by Chronic Neurodegeneration to Produce Exaggerated Chemokine and Cell Infiltration Responses to Acute Stimulation with the Cytokines IL-1β and TNF-α. J Neurosci 2015; 35:8411-22. [PMID: 26041910 DOI: 10.1523/jneurosci.2745-14.2015] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Microgliosis and astrogliosis are standard pathological features of neurodegenerative disease. Microglia are primed by chronic neurodegeneration such that toll-like receptor agonists, such as LPS, drive exaggerated cytokine responses on this background. However, sterile inflammatory insults are more common than direct CNS infection in the degenerating brain and these insults drive robust IL-1β and TNF-α responses. It is unclear whether these pro-inflammatory cytokines can directly induce exaggerated responses in the degenerating brain. We hypothesized that glial cells in the hippocampus of animals with chronic neurodegenerative disease (ME7 prion disease) would display exaggerated responses to central cytokine challenges. TNF-α or IL-1β were administered intrahippocampally to ME7-inoculated mice and normal brain homogenate-injected (NBH) controls. Both IL-1β and TNF-α produced much more robust IL-1β synthesis in ME7 than in NBH animals and this occurred exclusively in microglia. However, there was strong nuclear localization of the NFκB subunit p65 in the astrocyte population, associated with marked astrocytic synthesis of the chemokines CXCL1 and CCL2 in response to both cytokine challenges in ME7 animals. Conversely, very limited expression of these chemokines was apparent in NBH animals similarly challenged. Thus, astrocytes are primed in the degenerating brain to produce exaggerated chemokine responses to acute stimulation with pro-inflammatory cytokines. Furthermore, this results in markedly increased neutrophil, T-cell, and monocyte infiltration in the diseased brain. These data have significant implications for acute sterile inflammatory insults such as stroke and traumatic brain injury occurring on a background of aging or neurodegeneration.
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Zhang ZG, Li Y, Ng CT, Song YQ. Inflammation in Alzheimer's Disease and Molecular Genetics: Recent Update. Arch Immunol Ther Exp (Warsz) 2015; 63:333-44. [PMID: 26232392 DOI: 10.1007/s00005-015-0351-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 03/03/2015] [Indexed: 01/01/2023]
Abstract
Alzheimer's disease (AD) is a complex age-related neurodegenerative disorder of the central nervous system. Since the first description of AD in 1907, many hypotheses have been established to explain its causes. The inflammation theory is one of them. Pathological and biochemical studies of brains from AD individuals have provided solid evidence of the activation of inflammatory pathways. Furthermore, people with long-term medication of anti-inflammatory drugs have shown a reduced risk to develop the disease. After three decades of genetic study in AD, dozens of loci harboring genetic variants influencing inflammatory pathways in AD patients has been identified through genome-wide association studies (GWAS). The most well-known GWAS risk factor that is responsible for immune response and inflammation in AD development should be APOE ε4 allele. However, a growing number of other GWAS risk AD candidate genes in inflammation have recently been discovered. In the present study, we try to review the inflammation in AD and immunity-associated GWAS risk genes like HLA-DRB5/DRB1, INPP5D, MEF2C, CR1, CLU and TREM2.
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Affiliation(s)
- Zhi-Gang Zhang
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong, People's Republic of China
| | - Yan Li
- Energy Research Institute of Shandong Academy of Sciences, Jinan, Shandong, People's Republic of China
| | - Cheung Toa Ng
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong, People's Republic of China
| | - You-Qiang Song
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong, People's Republic of China. .,State Key Laboratory for Cognitive and Brain Sciences, The University of Hong Kong, Pokfulam, Hong Kong, People's Republic of China.
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44
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Fumagalli S, Perego C, Pischiutta F, Zanier ER, De Simoni MG. The ischemic environment drives microglia and macrophage function. Front Neurol 2015; 6:81. [PMID: 25904895 PMCID: PMC4389404 DOI: 10.3389/fneur.2015.00081] [Citation(s) in RCA: 184] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/25/2015] [Indexed: 12/16/2022] Open
Abstract
Cells of myeloid origin, such as microglia and macrophages, act at the crossroads of several inflammatory mechanisms during pathophysiology. Besides pro-inflammatory activity (M1 polarization), myeloid cells acquire protective functions (M2) and participate in the neuroprotective innate mechanisms after brain injury. Experimental research is making considerable efforts to understand the rules that regulate the balance between toxic and protective brain innate immunity. Environmental changes affect microglia/macrophage functions. Hypoxia can affect myeloid cell distribution, activity, and phenotype. With their intrinsic differences, microglia and macrophages respond differently to hypoxia, the former depending on ATP to activate and the latter switching to anaerobic metabolism and adapting to hypoxia. Myeloid cell functions include homeostasis control, damage-sensing activity, chemotaxis, and phagocytosis, all distinctive features of these cells. Specific markers and morphologies enable to recognize each functional state. To ensure homeostasis and activate when needed, microglia/macrophage physiology is finely tuned. Microglia are controlled by several neuron-derived components, including contact-dependent inhibitory signals and soluble molecules. Changes in this control can cause chronic activation or priming with specific functional consequences. Strategies, such as stem cell treatment, may enhance microglia protective polarization. This review presents data from the literature that has greatly advanced our understanding of myeloid cell action in brain injury. We discuss the selective responses of microglia and macrophages to hypoxia after stroke and review relevant markers with the aim of defining the different subpopulations of myeloid cells that are recruited to the injured site. We also cover the functional consequences of chronically active microglia and review pivotal works on microglia regulation that offer new therapeutic possibilities for acute brain injury.
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Affiliation(s)
- Stefano Fumagalli
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri , Milan , Italy ; Department of Pathophysiology and Transplantation, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico , Milan , Italy
| | - Carlo Perego
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri , Milan , Italy
| | - Francesca Pischiutta
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri , Milan , Italy
| | - Elisa R Zanier
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri , Milan , Italy
| | - Maria-Grazia De Simoni
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri , Milan , Italy
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Cunningham C, Hennessy E. Co-morbidity and systemic inflammation as drivers of cognitive decline: new experimental models adopting a broader paradigm in dementia research. ALZHEIMERS RESEARCH & THERAPY 2015; 7:33. [PMID: 25802557 PMCID: PMC4369837 DOI: 10.1186/s13195-015-0117-2] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Dementia prevalence increases with age and Alzheimer’s disease (AD) accounts for up to 75% of cases. However, significant variability and overlap exists in the extent of amyloid-β and Tau pathology in AD and non-demented populations and it is clear that other factors must influence progression of cognitive decline, perhaps independent of effects on amyloid pathology. Coupled with the failure of amyloid-clearing strategies to provide benefits for AD patients, it seems necessary to broaden the paradigm in dementia research beyond amyloid deposition and clearance. Evidence has emerged from alternative animal model approaches as well as clinical and population epidemiological studies that co-morbidities contribute significantly to neurodegeneration/cognitive decline and systemic inflammation has been a strong common theme in these approaches. We hypothesise, and discuss in this review, that a disproportionate inflammatory response to infection, injury or chronic peripheral disease is a key determinant of cognitive decline. We propose that detailed study of alternative models, which encompass acute and chronic systemic inflammatory co-morbidities, is an important priority for the field and we examine the cognitive consequences of several of these alternative experimental approaches. Experimental models of severe sepsis in normal animals or moderate acute systemic inflammation in animals with existing neurodegenerative pathology have uncovered roles for inflammatory mediators interleukin-1β, tumour necrosis factor-α, inducible nitric oxide synthase, complement, prostaglandins and NADPH oxidase in inflammation-induced cognitive dysfunction and neuronal death. Moreover, microglia are primed by existing neurodegenerative pathology to produce exaggerated responses to subsequent stimulation with bacterial lipopolysaccharide or other inflammatory stimuli and these insults drive acute dysfunction and negatively affect disease trajectory. Chronic co-morbidities, such as arthritis, atherosclerosis, obesity and diabetes, are risk factors for subsequent dementia and those with high inflammatory status are particularly at risk. Models of chronic co-morbidities, and indeed low grade systemic inflammation in the absence of specific pathology, indicate that interleukin-1β, tumour necrosis factor-α and other inflammatory mediators drive insulin resistance, hypothalamic dysfunction, impaired neurogenesis and cognitive function and impact on functional decline. Detailed study of these pathways will uncover important mechanisms of peripheral inflammation-driven cognitive decline and are already driving clinical initiatives to mitigate AD progression through minimising systemic inflammation.
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Affiliation(s)
- Colm Cunningham
- Trinity College Institute of Neuroscience and School of Biochemistry and Immunology, Trinity College Dublin, Dublin 2, Republic of Ireland
| | - Edel Hennessy
- Trinity College Institute of Neuroscience and School of Biochemistry and Immunology, Trinity College Dublin, Dublin 2, Republic of Ireland
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Farr SA, Erickson MA, Niehoff ML, Banks WA, Morley JE. Central and peripheral administration of antisense oligonucleotide targeting amyloid-β protein precursor improves learning and memory and reduces neuroinflammatory cytokines in Tg2576 (AβPPswe) mice. J Alzheimers Dis 2015; 40:1005-16. [PMID: 24577464 DOI: 10.3233/jad-131883] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease. Currently, there are no therapies to stop or reverse the symptoms of AD. We have developed an antisense oligonucleotide (OL-1) against the amyloid-β protein precursor (AβPP) that can decrease AβPP expression and amyloid-β protein (Aβ) production. This antisense rapidly crosses the blood-brain barrier, reverses learning and memory impairments, reduces oxidative stress, and restores brain-to-blood efflux of Aβ in SAMP8 mice. Here, we examined the effects of this AβPP antisense in the Tg2576 mouse model of AD. We administered the OL-1 antisense into the lateral ventricle 3 times at 2week intervals. Seventy-two hours after the third injection, we tested learning and memory in T-maze foot shock avoidance. In the second study, we injected the mice with OL-1 antisense 3 times at 2-week intervals via the tail vein. Seventy-two hours later, we tested learning and memory T-maze, novel object recognition, and elevated plus maze. At the end of behavioral testing, brain tissue was collected. OL-1 antisense administered centrally improved acquisition and retention of T-maze foot shock avoidance. OL-1 antisense administered via tail vein improved learning and memory in both T-maze foot shock avoidance and novel object-place recognition. In the elevated plus maze, the mice which received OL-1 antisense spent less time in the open arms and had fewer entries into the open arms indicating reduced disinhibitation. Biochemical analyses reveal significant reduction of AβPP signal and a reduction of measures of neuroinflammation. The current findings support the therapeutic potential of OL-1 AβPP antisense.
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Affiliation(s)
- Susan A Farr
- Research and Development Service, VA Medical Center, St. Louis, MO, USA Department of Internal Medicine, Division of Geriatric Medicine, St. Louis University School of Medicine, St. Louis, MO, USA
| | - Michelle A Erickson
- Geriatric Research Educational and Clinical Center (GRECC), Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA Department of Internal Medicine, Division of Gerontology and Geriatric Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - Michael L Niehoff
- Department of Internal Medicine, Division of Geriatric Medicine, St. Louis University School of Medicine, St. Louis, MO, USA
| | - William A Banks
- Geriatric Research Educational and Clinical Center (GRECC), Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA Department of Internal Medicine, Division of Gerontology and Geriatric Medicine, University of Washington School of Medicine, Seattle, WA, USA
| | - John E Morley
- Department of Internal Medicine, Division of Geriatric Medicine, St. Louis University School of Medicine, St. Louis, MO, USA Department of Internal Medicine, Division of Endocrinology, St. Louis University School of Medicine, St. Louis, MO, USA
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Murta V, Farías MI, Pitossi FJ, Ferrari CC. Chronic systemic IL-1β exacerbates central neuroinflammation independently of the blood-brain barrier integrity. J Neuroimmunol 2014; 278:30-43. [PMID: 25595250 DOI: 10.1016/j.jneuroim.2014.11.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 11/24/2014] [Accepted: 11/27/2014] [Indexed: 12/13/2022]
Abstract
Peripheral circulating cytokines are involved in immune to brain communication and systemic inflammation is considered a risk factor for flaring up the symptoms in most neurodegenerative diseases. We induced both central inflammatory demyelinating lesion, and systemic inflammation with an interleukin-1β expressing adenovector. The peripheral pro-inflammatory stimulus aggravated the ongoing central lesion independently of the blood-brain barrier (BBB) integrity. This model allows studying the role of specific molecules and cells (neutrophils) from the innate immune system, in the relationship between central and peripheral communication, and on relapsing episodes of demyelinating lesions, along with the role of BBB integrity.
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Affiliation(s)
- Verónica Murta
- Laboratorio de Terapias Regenerativas y Protectoras del Sistema Nervioso, Leloir Institute Foundation, Institute for Biochemical Investigations, CONICET, Buenos Aires, Argentina.
| | - María Isabel Farías
- Laboratorio de Terapias Regenerativas y Protectoras del Sistema Nervioso, Leloir Institute Foundation, Institute for Biochemical Investigations, CONICET, Buenos Aires, Argentina.
| | - Fernando Juan Pitossi
- Laboratorio de Terapias Regenerativas y Protectoras del Sistema Nervioso, Leloir Institute Foundation, Institute for Biochemical Investigations, CONICET, Buenos Aires, Argentina.
| | - Carina Cintia Ferrari
- Laboratorio de Terapias Regenerativas y Protectoras del Sistema Nervioso, Leloir Institute Foundation, Institute for Biochemical Investigations, CONICET, Buenos Aires, Argentina.
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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'.
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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.
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Cerebral protection: inflammation, endothelial dysfunction, and postoperative cognitive dysfunction. Curr Opin Anaesthesiol 2014; 27:89-97. [PMID: 24300462 DOI: 10.1097/aco.0000000000000032] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW Postoperative cognitive dysfunction (POCD) is a well recognized perioperative syndrome, with approximately 15% of patients over the age of 60 years displaying objectively measured decrease in cognitive function as a consequence of anesthesia and surgery. The exact cause, however, remains unknown. This review aims to update anesthesiologists on the recent advancements in the understanding of the pathophysiology of POCD. RECENT FINDINGS Recent evidence suggests that the observed predilection to POCD is likely mediated by a neuro-inflammatory response - with surgery being a major contributing factor. The blood-brain barrier, a highly specialized endothelial layer, is exquisitely sensitive to an inflammatory insult and implicated in the cause of other neurocognitive syndromes also characterized by neuro-inflammation such as cerebral malaria. Inflammatory changes may disrupt the blood-brain barrier and facilitate migration of macrophages into the brain, damaging synapses and neurones and ultimately lead to POCD. This review explores the important question of causality - the potential relationship between inflammation, endothelial dysfunction, and postoperative cognitive decline. SUMMARY Recent research points to a central role of a neuro-inflammatory cascade in POCD, with endothelial dysfunction potentially aggravating the insult. Investigating the genomic and molecular mechanisms that underlie the intervariation in the inflammatory response to surgery, improving the identification of appropriate endothelial and inflammatory biomarkers, and developing endothelial modulatory and anti-inflammatory (prevention and resolution) strategies are key areas of future translational research. This is important as the elderly, who show increased susceptibility to this and other perioperative illness syndromes, represent an ever-increasing proportion of patients presenting for surgery.
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Treadmill exercise represses neuronal cell death and inflammation during Aβ-induced ER stress by regulating unfolded protein response in aged presenilin 2 mutant mice. Apoptosis 2014; 18:1332-1347. [PMID: 23907580 DOI: 10.1007/s10495-013-0884-9] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Alzheimer's disease (AD) is characterized by the deposition of aggregated amyloid-beta (Aβ), which triggers a cellular stress response called the unfolded protein response (UPR). The UPR signaling pathway is a cellular defense system for dealing with the accumulation of misfolded proteins but switches to apoptosis when endoplasmic reticulum (ER) stress is prolonged. ER stress is involved in neurodegenerative diseases including AD, but the molecular mechanisms of neuronal apoptosis and inflammation by Aβ-induced ER stress to exercise training are not fully understood. Here, we demonstrated that treadmill exercise (TE) prevented PS2 mutation-induced memory impairment and reduced Aβ-42 deposition through the inhibition of β-secretase (BACE-1) and its product, C-99 in cortex and/or hippocampus of aged PS2 mutant mice. We also found that TE down-regulated the expression of GRP78/Bip and PDI proteins and inhibited activation of PERK, eIF2α, ATF6α, sXBP1 and JNK-p38 MAPK as well as activation of CHOP, caspase-12 and caspase-3. Moreover, TE up-regulated the expression of Bcl-2 and down-regulated the expressions of Bax in the hippocampus of aged PS2 mutant mice. Finally, the generation of TNFα and IL-1α and the number of TUNEL-positive cells in the hippocampus of aged PS2 mutant mice was also prevented or decreased by TE. These results showed that TE suppressed the activation of UPR signaling pathways as well as inhibited the apoptotic pathways of the UPR and inflammatory response following Aβ-induced ER stress. Thus, therapeutic strategies that modulate Aβ-induced ER stress through TE could represent a promising approach for the prevention or treatment of AD.
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