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Sinclair D, Canty AJ, Ziebell JM, Woodhouse A, Collins JM, Perry S, Roccati E, Kuruvilla M, Leung J, Atkinson R, Vickers JC, Cook AL, King AE. Experimental laboratory models as tools for understanding modifiable dementia risk. Alzheimers Dement 2024; 20:4260-4289. [PMID: 38687209 PMCID: PMC11180874 DOI: 10.1002/alz.13834] [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: 12/13/2023] [Revised: 02/29/2024] [Accepted: 03/18/2024] [Indexed: 05/02/2024]
Abstract
Experimental laboratory research has an important role to play in dementia prevention. Mechanisms underlying modifiable risk factors for dementia are promising targets for dementia prevention but are difficult to investigate in human populations due to technological constraints and confounds. Therefore, controlled laboratory experiments in models such as transgenic rodents, invertebrates and in vitro cultured cells are increasingly used to investigate dementia risk factors and test strategies which target them to prevent dementia. This review provides an overview of experimental research into 15 established and putative modifiable dementia risk factors: less early-life education, hearing loss, depression, social isolation, life stress, hypertension, obesity, diabetes, physical inactivity, heavy alcohol use, smoking, air pollution, anesthetic exposure, traumatic brain injury, and disordered sleep. It explores how experimental models have been, and can be, used to address questions about modifiable dementia risk and prevention that cannot readily be addressed in human studies. HIGHLIGHTS: Modifiable dementia risk factors are promising targets for dementia prevention. Interrogation of mechanisms underlying dementia risk is difficult in human populations. Studies using diverse experimental models are revealing modifiable dementia risk mechanisms. We review experimental research into 15 modifiable dementia risk factors. Laboratory science can contribute uniquely to dementia prevention.
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Affiliation(s)
- Duncan Sinclair
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Alison J. Canty
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
- Global Brain Health Institute, Trinity CollegeDublinIreland
| | - Jenna M. Ziebell
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Adele Woodhouse
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Jessica M. Collins
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Sharn Perry
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Eddy Roccati
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Maneesh Kuruvilla
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Jacqueline Leung
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Rachel Atkinson
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - James C. Vickers
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Anthony L. Cook
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Anna E. King
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
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2
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Yu M, Feng L, Zhao X, Huang Q, Xia N, Xia H, Wen C, Wang M, Zhu Z, Yang Y. The interaction of global small vessel disease burden and Alzheimer's disease pathologies do not change the independent association of amyloid-beta with hippocampal volume: A longitudinal study on mild cognitive impairment subjects. Hippocampus 2023; 33:1197-1207. [PMID: 37638636 DOI: 10.1002/hipo.23573] [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: 04/02/2023] [Revised: 08/04/2023] [Accepted: 08/13/2023] [Indexed: 08/29/2023]
Abstract
The purpose of this study was to investigate whether the co-existence of global small vessel disease (SVD) burdens and Alzheimer's disease (AD) pathologies change hippocampal volume (HV) and cognitive function of mild cognitive impairment (MCI) subjects. We obtained MRI images, cerebrospinal fluid biomarkers (Aβ1-42 and p-tau), and neuropsychological tests of 310 MCI subjects from ADNI. The global SVD score was assessed. We used linear regression and linear mixing effect to analyze the effects of global SVD burdens, AD pathologies, and their interactions (SVD*AD) on baseline and longitudinal HV and cognition respectively. We used simple mediation effect to analyze the influencing pathways. After adjusting for global SVD and SVD*AD, Aβ remained independently correlated with baseline and longitudinal HV (std β = 0.294, p = .007; std β = 0.292, p < .001), indicating that global SVD did not affect the correlation between Aβ and HV. Global SVD score was correlated with longitudinal but not baseline HV (std β = 0.470, p = .050), suggesting that global SVD may be more representative of long-term permanent impairment. Global SVD, AD pathologies, and SVD*AD were independently correlated with baseline and longitudinal cognitions, in which the association of Aβ (B = 0.005, 95% CI: 0.005; 0.024) and p-tau (B = -0.002, 95% CI: -0.004; -0.000) with cognition were mediated by HV, suggesting that HV is more likely to explain the progression caused by AD pathology than SVD. The co-existence of global SVD and AD pathologies did not affect the individual association of Aβ on HV; HV played a more important role in the influence of AD pathology on cognition than in SVD.
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Affiliation(s)
- Mengying Yu
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
| | - Lufei Feng
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
- Department of Radiology, Zhuji Central Hospital, Zhejiang, China
| | - Xuemiao Zhao
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
| | - Qun Huang
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
| | - Nengzhi Xia
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
| | - Huwei Xia
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
| | - Caiyun Wen
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
| | - Meihao Wang
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
| | - Zili Zhu
- Department of Imaging, Ningbo City First Hospital, Zhejiang, China
| | - Yunjun Yang
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University, Zhejiang, China
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Sun N, Cui WQ, Min XM, Zhang GM, Liu JZ, Wu HY. A new perspective on hippocampal synaptic plasticity and post-stroke depression. Eur J Neurosci 2023; 58:2961-2984. [PMID: 37518943 DOI: 10.1111/ejn.16093] [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: 04/11/2023] [Revised: 07/01/2023] [Accepted: 07/03/2023] [Indexed: 08/01/2023]
Abstract
Post-stroke depression, a common complication after stroke, severely affects the recovery and quality of life of patients with stroke. Owing to its complex mechanisms, post-stroke depression treatment remains highly challenging. Hippocampal synaptic plasticity is one of the key factors leading to post-stroke depression; however, the precise molecular mechanisms remain unclear. Numerous studies have found that neurotrophic factors, protein kinases and neurotransmitters influence depressive behaviour by modulating hippocampal synaptic plasticity. This review further elaborates on the role of hippocampal synaptic plasticity in post-stroke depression by summarizing recent research and analysing possible molecular mechanisms. Evidence for the correlation between hippocampal mechanisms and post-stroke depression helps to better understand the pathological process of post-stroke depression and improve its treatment.
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Affiliation(s)
- Ning Sun
- First College of Clinical Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Wen-Qiang Cui
- Department of Neurology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xiao-Man Min
- College of Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Guang-Ming Zhang
- College of Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Jia-Zheng Liu
- College of Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Hong-Yun Wu
- Department of Neurology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
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MacKenzie JL, Ivanova N, Nell HJ, Giordano CR, Terlecky SR, Agca C, Agca Y, Walton PA, Whitehead SN, Cechetto DF. Microglial inflammation and cognitive dysfunction in comorbid rat models of striatal ischemic stroke and alzheimer’s disease: effects of antioxidant catalase-SKL on behavioral and cellular pathology. Neuroscience 2022; 487:47-65. [DOI: 10.1016/j.neuroscience.2022.01.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 12/25/2022]
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5
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Gao Y, Liu J, Wang J, Liu Y, Zeng LH, Ge W, Ma C. Proteomic analysis of human hippocampal subfields provides new insights into the pathogenesis of Alzheimer's disease and the role of glial cells. Brain Pathol 2022; 32:e13047. [PMID: 35016256 PMCID: PMC9245939 DOI: 10.1111/bpa.13047] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/30/2021] [Accepted: 12/09/2021] [Indexed: 01/23/2023] Open
Abstract
The hippocampus and entorhinal cortex (EC), the earliest affected areas, are considered relative to early memory loss in Alzheimer's disease (AD). The hippocampus is composed of heterogeneous subfields that are affected in a different order and varying degrees during AD pathogenesis. In this study, we conducted a comprehensive proteomic analysis of the hippocampal subfields and EC region in human postmortem specimens obtained from the Chinese human brain bank. Bioinformatics analysis identified region‐consistent differentially expressed proteins (DEPs) which associated with astrocytes, and region‐specific DEPs which associated with oligodendrocytes and the myelin sheath. Further analysis illuminated that the region‐consistent DEPs functioned as connection of region‐specific DEPs. Moreover, in region‐consistent DEPs, the expression level of S100A10, a marker of protective astrocytes, was increased in both aging and AD patients. Immunohistochemical analysis confirmed an increase in the number of S100A10‐positive astrocytes in all hippocampal subfields and the EC region of AD patients. Dual immunofluorescence results further showed that S100A10‐positive astrocytes contained apoptotic neuron debris in AD patients, suggesting that S100A10‐positive astrocytes may protect brain through phagocytosis of apoptotic neurons. In region‐specific DEPs, the proteome showed a specific reduction of oligodendrocytes and myelin markers in CA1, CA3, and EC regions of AD patients. Immunohistochemical analysis confirmed the loss of myelin in EC region. Above all, these results highlight the role of the glial cells in AD and provide new insights into the pathogenesis of AD and potential therapeutic strategies.
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Affiliation(s)
- Yanpan Gao
- School of Medicine, Zhejiang University City College, Hangzhou, China.,State Key Laboratory of Medical Molecular Biology, Department of Immunology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
| | - Jiaqi Liu
- Department of Human Anatomy, Histology and Embryology, Neuroscience Center, National Human Brain Bank for Development and Function, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
| | - Jiayu Wang
- Department of Human Anatomy, Histology and Embryology, Neuroscience Center, National Human Brain Bank for Development and Function, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China.,Department of Histology and Embryology, Basic Medical College, China Medical University, Shenyang, China
| | - Yifan Liu
- Department of Neurosurgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Ling-Hui Zeng
- School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Wei Ge
- State Key Laboratory of Medical Molecular Biology, Department of Immunology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China.,Hebei Key Laboratory of Chronic Kidney Diseases and Bone Metabolism, Affiliated Hospital of Hebei University, Baoding, China
| | - Chao Ma
- Department of Human Anatomy, Histology and Embryology, Neuroscience Center, National Human Brain Bank for Development and Function, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
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6
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Stuckey SM, Ong LK, Collins-Praino LE, Turner RJ. Neuroinflammation as a Key Driver of Secondary Neurodegeneration Following Stroke? Int J Mol Sci 2021; 22:ijms222313101. [PMID: 34884906 PMCID: PMC8658328 DOI: 10.3390/ijms222313101] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/25/2021] [Accepted: 12/01/2021] [Indexed: 01/13/2023] Open
Abstract
Ischaemic stroke involves the rapid onset of focal neurological dysfunction, most commonly due to an arterial blockage in a specific region of the brain. Stroke is a leading cause of death and common cause of disability, with over 17 million people worldwide suffering from a stroke each year. It is now well-documented that neuroinflammation and immune mediators play a key role in acute and long-term neuronal tissue damage and healing, not only in the infarct core but also in distal regions. Importantly, in these distal regions, termed sites of secondary neurodegeneration (SND), spikes in neuroinflammation may be seen sometime after the initial stroke onset, but prior to the presence of the neuronal tissue damage within these regions. However, it is key to acknowledge that, despite the mounting information describing neuroinflammation following ischaemic stroke, the exact mechanisms whereby inflammatory cells and their mediators drive stroke-induced neuroinflammation are still not fully understood. As a result, current anti-inflammatory treatments have failed to show efficacy in clinical trials. In this review we discuss the complexities of post-stroke neuroinflammation, specifically how it affects neuronal tissue and post-stroke outcome acutely, chronically, and in sites of SND. We then discuss current and previously assessed anti-inflammatory therapies, with a particular focus on how failed anti-inflammatories may be repurposed to target SND-associated neuroinflammation.
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Affiliation(s)
- Shannon M. Stuckey
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
| | - Lin Kooi Ong
- School of Pharmacy, Monash University Malaysia, Subang Jaya 47500, Malaysia;
- School of Biomedical Sciences and Pharmacy and the Priority Research Centre for Stroke and Brain Injury, The University of Newcastle, Callaghan 2308, Australia
| | - Lyndsey E. Collins-Praino
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
| | - Renée J. Turner
- Discipline of Anatomy and Pathology, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5005, Australia; (S.M.S.); (L.E.C.-P.)
- Correspondence: ; Tel.: +61-8-8313-3114
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7
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Paulo SL, Ribeiro-Rodrigues L, Rodrigues RS, Mateus JM, Fonseca-Gomes J, Soares R, Diógenes MJ, Solá S, Sebastião AM, Ribeiro FF, Xapelli S. Sustained Hippocampal Neural Plasticity Questions the Reproducibility of an Amyloid-β-Induced Alzheimer's Disease Model. J Alzheimers Dis 2021; 82:1183-1202. [PMID: 34151790 DOI: 10.3233/jad-201567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The use of Alzheimer's disease (AD) models obtained by intracerebral infusion of amyloid-β (Aβ) has been increasingly reported in recent years. Nonetheless, these models may present important challenges. OBJECTIVE We have focused on canonical mechanisms of hippocampal-related neural plasticity to characterize a rat model obtained by an intracerebroventricular (icv) injection of soluble amyloid-β42 (Aβ42). METHODS Animal behavior was evaluated in the elevated plus maze, Y-Maze spontaneous or forced alternation, Morris water maze, and open field, starting 2 weeks post-Aβ42 infusion. Hippocampal neurogenesis was assessed 3 weeks after Aβ42 injection. Aβ deposition, tropomyosin receptor kinase B levels, and neuroinflammation were appraised at 3 and 14 days post-Aβ42 administration. RESULTS We found that immature neuronal dendritic morphology was abnormally enhanced, but proliferation and neuronal differentiation in the dentate gyrus was conserved one month after Aβ42 injection. Surprisingly, animal behavior did not reveal changes in cognitive performance nor in locomotor and anxious-related activity. Brain-derived neurotrophic factor related-signaling was also unchanged at 3 and 14 days post-Aβ icv injection. Likewise, astrocytic and microglial markers of neuroinflammation in the hippocampus were unaltered in these time points. CONCLUSION Taken together, our data emphasize a high variability and lack of behavioral reproducibility associated with these Aβ injection-based models, as well as the need for its further optimization, aiming at addressing the gap between preclinical AD models and the human disorder.
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Affiliation(s)
- Sara L Paulo
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Leonor Ribeiro-Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Rui S Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Joana M Mateus
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - João Fonseca-Gomes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Rita Soares
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Biologia Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Maria J Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Susana Solá
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Filipa F Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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8
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Mesnil M, Defamie N, Naus C, Sarrouilhe D. Brain Disorders and Chemical Pollutants: A Gap Junction Link? Biomolecules 2020; 11:biom11010051. [PMID: 33396565 PMCID: PMC7824109 DOI: 10.3390/biom11010051] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/07/2023] Open
Abstract
The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.
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Affiliation(s)
- Marc Mesnil
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Norah Defamie
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Christian Naus
- Faculty of Medicine, Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T1Z3, Canada;
| | - Denis Sarrouilhe
- Laboratoire de Physiologie Humaine, Faculté de Médecine et Pharmacie, 6 rue de La Milétrie, bât D1, TSA 51115, 86073 Poitiers, France
- Correspondence: ; Tel.: +33-5-49-45-43-58
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Yao G, Li J, Liu S, Wang J, Cao X, Li X, Cheng L, Chen H, Xu Y. Alterations of Functional Connectivity in Stroke Patients With Basal Ganglia Damage and Cognitive Impairment. Front Neurol 2020; 11:980. [PMID: 33013648 PMCID: PMC7511868 DOI: 10.3389/fneur.2020.00980] [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: 04/30/2020] [Accepted: 07/28/2020] [Indexed: 01/01/2023] Open
Abstract
Background: Stroke with basal ganglia damage (SBG) is a neurological disorder characterized by cognitive impairment. The neurobiological mechanism of cognitive impairment in stroke patients with basal ganglia damage (SBG patients) remains unclear. This study aimed to explore the underlying neurobiological mechanism of cognitive impairment in SBG patients using resting-state functional magnetic resonance imaging (rs-fMRI). Methods: The differences in functional connectivity (FC) between 14 SBG patients (average age: 61.00 ± 7.45 years) and 21 healthy controls (HC) (average age: 60.67 ± 6.95 years) were examined using voxel-mirrored homotopic connectivity (VMHC) and degree centrality (DC). Moreover, we compared the cognitive functions of SBG patients with HC using the Chinese Revised Wechsler Adult Intelligence Scale (WAIS-RC) and Wechsler Memory Scale (WMS). Results: Full-scale intelligence quotient (FIQ) (t = 2.810, p < 0.010) and memory quotient (MQ) (t = 2.920, p < 0.010) scores of SBG patients were significantly lower than those of HC. Compared with HC, significantly decreased VMHC values in the bilateral angular gyrus, supramarginal gyrus, inferior frontal gyrus, middle temporal gyrus, hippocampus, precuneus, precentral gyrus, and middle occipital gyrus and decreased DC values in the right supramarginal gyrus, bilateral angular gyrus, and right postcentral gyrus were observed in SBG patients. Moreover, the VMHC values in the angular gyrus, inferior frontal gyrus, supramarginal gyrus, and middle temporal gyrus and the DC values in the right supramarginal gyrus were significantly correlated with cognitive functions in all participants. Conclusion: Our findings may provide a neural basis for cognitive impairments in SBG patients. Furthermore, local abnormalities of functional networks and interhemispheric interaction deficits may provide new ideas and insights for understanding and treating SBG patients' cognitive impairments.
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Affiliation(s)
- Guanqun Yao
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
| | - Jing Li
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China.,Shanxi Key Laboratory of Artificial Intelligence Assisted Diagnosis and Treatment for Mental Disorder, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Sha Liu
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China.,Shanxi Key Laboratory of Artificial Intelligence Assisted Diagnosis and Treatment for Mental Disorder, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Jiaojian Wang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.,Center for Language and Brain, Shenzhen Institute of Neuroscience, Shenzhen, China
| | - Xiaohua Cao
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
| | - Xinrong Li
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
| | - Long Cheng
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
| | - Huafu Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Yong Xu
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China.,Shanxi Key Laboratory of Artificial Intelligence Assisted Diagnosis and Treatment for Mental Disorder, First Hospital of Shanxi Medical University, Taiyuan, China.,MDT Center for Cognitive Impairment and Sleep Disorders, First Hospital of Shanxi Medical University, Taiyuan, China
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10
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Simões-Pires EN, Ferreira ST, Linden R. Roles of glutamate receptors in a novel in vitro model of early, comorbid cerebrovascular, and Alzheimer's diseases. J Neurochem 2020; 156:539-552. [PMID: 32683713 DOI: 10.1111/jnc.15129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 07/13/2020] [Accepted: 07/13/2020] [Indexed: 11/28/2022]
Abstract
Systemic multimorbidity is highly prevalent in the elderly and, remarkably, coexisting neuropathological markers of Alzheimer's (AD) and cerebrovascular (CVD) diseases are found at autopsy in most brains of patients clinically diagnosed as AD. Little is known on neurodegeneration peculiar to comorbidities, especially at early stages when pathogenesis may propagate at subclinical levels. We developed a novel in vitro model of comorbid CVD/AD in organotypic hippocampal cultures, by combining oxygen-glucose deprivation (OGD) and exposure to amyloid-Aβ oligomers (AβOs), both applied at levels subtoxic to neurons when used in isolation. We focused on synaptic proteins and the roles of glutamate receptors, which have been implicated in many basic and clinical approaches to either CVD or AD. Subtoxic insults by OGD and AβOs synergized to reduce levels of synaptophysin (SYP) and PSD-95 without cell death, while effects of antagonists of either metabotropic or ionotropic glutamate receptors were distinct from reports in models of isolated CVD or AD. In particular, modulation of glutamate receptors differentially impacted SYP and PSD-95, and antagonists of a single receptor subtype had distinct effects when either isolated or combined. Our findings highlight the complexity of CVD/AD comorbidity, help understand variable responses to glutamate receptor antagonists in patients diagnosed with AD and may contribute to future development of therapeutics based on investigation of the pattern of progressive comorbidity.
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Affiliation(s)
| | - Sergio T Ferreira
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto de Bioquímica Médica Leopoldo de Meis, UFRJ, Rio de Janeiro, Brazil
| | - Rafael Linden
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil
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11
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Hagberg G, Ihle-Hansen H, Fure B, Thommessen B, Ihle-Hansen H, Øksengård AR, Beyer MK, Wyller TB, Müller EG, Pendlebury ST, Selnes P. No evidence for amyloid pathology as a key mediator of neurodegeneration post-stroke - a seven-year follow-up study. BMC Neurol 2020; 20:174. [PMID: 32384876 PMCID: PMC7206753 DOI: 10.1186/s12883-020-01753-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 04/29/2020] [Indexed: 12/24/2022] Open
Abstract
Background Cognitive impairment (CI) with mixed vascular and neurodegenerative pathologies after stroke is common. The role of amyloid pathology in post-stroke CI is unclear. We hypothesize that amyloid deposition, measured with Flutemetamol (18F-Flut) positron emission tomography (PET), is common in seven-year stroke survivors diagnosed with CI and, further, that quantitatively assessed 18F-Flut-PET uptake after 7 years correlates with amyloid-β peptide (Aβ42) levels in cerebrospinal fluid (CSF) at 1 year, and with measures of neurodegeneration and cognition at 7 years post-stroke. Methods 208 patients with first-ever stroke or transient Ischemic Attack (TIA) without pre-existing CI were included during 2007 and 2008. At one- and seven-years post-stroke, cognitive status was assessed, and categorized into dementia, mild cognitive impairment or normal. Etiologic sub-classification was based on magnetic resonance imaging (MRI) findings, CSF biomarkers and clinical cognitive profile. At 7 years, patients were offered 18F-Flut-PET, and amyloid-positivity was assessed visually and semi-quantitatively. The associations between 18F-Flut-PET standardized uptake value ratios (SUVr) and measures of neurodegeneration (medial temporal lobe atrophy (MTLA), global cortical atrophy (GCA)) and cognition (Mini-Mental State Exam (MMSE), Trail-making test A (TMT-A)) and CSF Aβ42 levels were assessed using linear regression. Results In total, 111 patients completed 7-year follow-up, and 26 patients agreed to PET imaging, of whom 13 had CSF biomarkers from 1 year. Thirteen out of 26 patients were diagnosed with CI 7 years post-stroke, but only one had visually assessed amyloid positivity. CSF Aβ42 levels at 1 year, MTA grade, GCA scale, MMSE score or TMT-A at 7 years did not correlate with 18F-Flut-PET SUVr in this cohort. Conclusions Amyloid binding was not common in 7-year stroke survivors diagnosed with CI. Quantitatively assessed, cortical amyloid deposition did not correlate with other measures related to neurodegeneration or cognition. Therefore, amyloid pathology may not be a key mediator of neurodegeneration 7 years post-stroke. Trial registration Clinicaltrials.gov (NCT00506818). July 23, 2007. Inclusion from February 2007, randomization and intervention from May 2007 and trial registration in July 2007.
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Affiliation(s)
- Guri Hagberg
- Bærum Hospital, Vestre Viken Hospital Trust, N-3004, Drammen, Norway. .,Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Hege Ihle-Hansen
- Bærum Hospital, Vestre Viken Hospital Trust, N-3004, Drammen, Norway.,Department of Geriatric Medicine, Oslo University Hospital, Oslo, Norway
| | - Brynjar Fure
- Department of Neurology, Department of Internal Medicine, Central Hospital Karlstad and Faculty of Medicine, Örebro University, Örebro, Sweden
| | - Bente Thommessen
- Department of Neurology, Akershus University Hospital, Oslo, Norway
| | - Håkon Ihle-Hansen
- Bærum Hospital, Vestre Viken Hospital Trust, N-3004, Drammen, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | | | - Mona K Beyer
- Division of Radiology, Nuclear Medicine Oslo University Hospital, Oslo, Norway
| | - Torgeir B Wyller
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Geriatric Medicine, Oslo University Hospital, Oslo, Norway
| | - Ebba Gløersen Müller
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Sarah T Pendlebury
- Centre for Prevention of Stroke and Dementia, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, UK
| | - Per Selnes
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Neurology, Akershus University Hospital, Oslo, Norway
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12
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Modeling Mixed Vascular and Alzheimer's Dementia Using Focal Subcortical Ischemic Stroke in Human ApoE4-TR:5XFAD Transgenic Mice. Transl Stroke Res 2020; 11:1064-1076. [PMID: 32086779 PMCID: PMC10075511 DOI: 10.1007/s12975-020-00786-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 01/14/2020] [Accepted: 02/03/2020] [Indexed: 10/25/2022]
Abstract
Subcortical white matter ischemic lesions are increasingly recognized to have pathologic overlap in individuals with Alzheimer's disease (AD). The interaction of white matter ischemic lesions with amyloid pathology seen in AD is poorly characterized. We designed a novel mouse model of subcortical white matter ischemic stroke and AD that can inform our understanding of the cellular and molecular mechanisms of mixed vascular and AD dementia. Subcortical white matter ischemic stroke underlying forelimb motor cortex was induced by local stereotactic injection of an irreversible eNOS inhibitor. Subcortical white matter ischemic stroke or sham procedures were performed on human ApoE4-targeted-replacement (TR):5XFAD mice at 8 weeks of age. Behavioral tests were done at 7, 10, 15, and 20 weeks. A subset of animals underwent 18FDG-PET/CT. At 20 weeks of age, brain tissue was examined for amyloid plaque accumulation and cellular changes. Compared with sham E4-TR:5XFAD mice, those with an early subcortical ischemic stroke showed a significant reduction in amyloid plaque burden in the region of cortex overlying the subcortical stroke. Cognitive performance was improved in E4-TR:5XFAD mice with stroke compared with sham E4-TR:5XFAD animals. Iba-1+ microglial cells in the region of cortex overlying the subcortical stroke were increased in number and morphologic complexity compared with sham E4-TR:5XFAD mice, suggesting that amyloid clearance may be promoted by an interaction between activated microglia and cortical neurons in response to subcortical stroke. This novel approach to modeling mixed vascular and AD dementia provides a valuable tool for dissecting the molecular interactions between these two common pathologies.
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13
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He JT, LI XY, Yang L, Zhao X. Astroglial connexins and cognition: memory formation or deterioration? Biosci Rep 2020; 40:BSR20193510. [PMID: 31868207 PMCID: PMC6954363 DOI: 10.1042/bsr20193510] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 01/20/2023] Open
Abstract
Connexins are the membrane proteins that form high-conductance plasma membrane channels and are the important constituents of gap junctions and hemichannels. Among different types of connexins, connexin 43 is the most widely expressed and studied gap junction proteins in astrocytes. Due to the key involvement of astrocytes in memory impairment and abundant expression of connexins in astrocytes, astroglial connexins have been projected as key therapeutic targets for Alzheimer's disease. On the other hand, the role of connexin gap junctions and hemichannels in memory formation and consolidation has also been reported. Moreover, deletion of these proteins and loss of gap junction communication result in loss of short-term spatial memory. Accordingly, both memory formation and memory deteriorating functions of astrocytes-located connexins have been documented. Physiologically expressed connexins may be involved in the memory formation, while pathologically increased expression of connexins with consequent excessive activation of astrocytes may induce neuronal injury and cognitive decline. The present review describes the memory formation as well as memory deteriorating functions of astroglial connexins in memory disorders of different etiology with possible mechanisms.
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Affiliation(s)
- Jin-Ting He
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun, 130033, Jilin Province, China
| | - Xiao-Yan LI
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun, 130033, Jilin Province, China
| | - Le Yang
- Department of Endocrinology, The People’s Hospital of Jilin Province, Changchun 130031, China
| | - Xin Zhao
- Department of Paediatrics, The First Hospital of Jilin University, Changchun, Jilin 130021, China
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14
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Amtul Z, Frías C, Randhawa J, Hill DJ, Arany EJ. The spatial cerebral damage caused by larger infarct and β-amyloid toxicity is driven by the anatomical/functional connectivity. J Comp Neurol 2020; 528:48-60. [PMID: 31265125 DOI: 10.1002/cne.24738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 06/04/2019] [Accepted: 06/18/2019] [Indexed: 11/07/2022]
Abstract
Large cerebral infarctions are major predictors of death and severe disability from stroke. Conversely, data concerning these types of infarctions and the affected adjacent brain circuits are scarce. It remains to be determined if the co-morbid concurrence of large infarct and β-amyloid (Aβ) toxicity can precipitate the early development of dementia. Here, we described a dose-dependent effect of a unilateral striatal injection of vasoconstrictive endothelin-1 (ET-1) along with Aβ toxicity on CNS pathogenesis; driven by the anatomical and functional networks within a brain circuit. After 21 days of treatment, a high dose (60 pmol) of ET-1 (E60) alone caused the greatest increase in neuroinflammation, mainly in the ipsilateral striatum and distant regions with synaptic links to the striatal lesion such as white matter (subcortical white matter, corpus callosum, internal capsule, anterior commissure), gray matter (globus pallidus, thalamus), and cortices (cingulate, motor, somatosensory, entorhinal). The combined E60 + Aβ treatment also extended perturbation in the contralateral hemisphere of these rats, such as increased deposition of amyloid precursor protein fragments associated with the appearance of degenerating cells and the leakage of laminin from the basement membrane across a compromised blood-brain barrier. However, the cerebral damage induced by the 6 pmol ET-1 (E6), Aβ and E6 + Aβ rats was not detrimental enough to injure the complete network. The appreciation of the causal interactions among distinct anatomical units in the brain after ischemia and Aβ toxicity will help in the design of effective and alternative therapeutics that may disassociate the synergistic or additive association between the infarcts and Aβ toxicity.
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Affiliation(s)
- Zareen Amtul
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Carmen Frías
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Jasmine Randhawa
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - David J Hill
- Department of Medicine, Physiology, and Pharmacology, and Pediatrics, University of Western Ontario, London, Ontario, Canada.,Lawson Health Research Institute, London, Ontario, Canada
| | - Edith J Arany
- Department of Pathology and Laboratory Medicine, University of Western Ontario, London, Ontario, Canada
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15
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Amtul Z, Yang J, Lee TY, Cechetto DF. Pathological Changes in Microvascular Morphology, Density, Size and Responses Following Comorbid Cerebral Injury. Front Aging Neurosci 2019; 11:47. [PMID: 30971910 PMCID: PMC6445844 DOI: 10.3389/fnagi.2019.00047] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/19/2019] [Indexed: 12/14/2022] Open
Abstract
Aberrations in brain microcirculation and the associated increase in blood-brain-barrier (BBB) permeability in addition to neuroinflammation and Aβ deposition observed in Alzheimer’s disease (AD) and ischemia have gained considerable attention recently. However, the role of microvascular homeostasis as a pathogenic substrate to disturbed microperfusion as well as an overlapping etiologic mechanism between AD and ischemia has not been thoroughly explored. In this study, we employ temporal histopathology of cerebral vasculature in a rat model of β-amyloid (Aβ) toxicity and endothelin-1 induced-ischemia (ET1) to investigate the panorama of cerebral pathology and the protein expression on d1, d7, and d28 post-injury. The combination of Aβ and ET1 pathological states leads to an alteration in microvascular anatomy, texture, diameter, density, and protein expression, in addition to disturbed vessel-matrix-connections, inter-compartmental water exchange and basement membrane profile within the lesion epicenter localized in the striatum of Aβ+ET1 brains compared to Aβ and ET1 rats. We conclude that the neural microvascular network, in addition to the neural tissue, is not only sensitive to structural deterioration but also serves as an underlying vascular etiology between ischemia and AD pathologies. Such investigation can provide prospects to appreciate the interrelationships between structure and responses of cerebral microvasculature and to provide a venue for vascular remodeling as a new treatment strategy.
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Affiliation(s)
- Zareen Amtul
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, Canada
| | - Jun Yang
- Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - Ting-Yim Lee
- Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - David F Cechetto
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, Canada
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16
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Nguyen TVV, Hayes M, Zbesko JC, Frye JB, Congrove NR, Belichenko NP, McKay BS, Longo FM, Doyle KP. Alzheimer's associated amyloid and tau deposition co-localizes with a homeostatic myelin repair pathway in two mouse models of post-stroke mixed dementia. Acta Neuropathol Commun 2018; 6:100. [PMID: 30249297 PMCID: PMC6154927 DOI: 10.1186/s40478-018-0603-4] [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: 08/14/2018] [Accepted: 09/19/2018] [Indexed: 11/23/2022] Open
Abstract
The goal of this study was to determine the chronic impact of stroke on the manifestation of Alzheimer’s disease (AD) related pathology and behavioral impairments in mice. To accomplish this goal, we used two distinct models. First, we experimentally induced ischemic stroke in aged wildtype (wt) C57BL/6 mice to determine if stroke leads to the manifestation of AD-associated pathological β-amyloid (Aβ) and tau in aged versus young adult wt mice. Second, we utilized a transgenic (Tg) mouse model of AD (hAPP-SL) to determine if stroke leads to the worsening of pre-existing AD pathology, as well as the development of pathology in brain regions not typically expressed in AD Tg mice. In the wt mice, there was delayed motor recovery and an accelerated development of cognitive deficits in aged mice compared to young adult mice following stroke. This corresponded with increased brain atrophy, increased cholinergic degeneration, and a focal increase of Aβ in areas of axonal degeneration in the ipsilateral hemisphere of the aged animals. By contrast, in the hAPP-SL mice, we found that ischemia induced aggravated behavioral deficits in conjunction with a global increase in Aβ, tau, and cholinergic pathology compared to hAPP-SL mice that underwent a sham stroke procedure. With regard to a potential mechanism, in both models, we found that the stroke-induced Aβ and tau deposits co-localized with increased levels of β-secretase 1 (BACE1), along with its substrate, neuregulin 1 (NGR1) type III, both of which are proteins integral for myelin repair. Based on these findings, we propose that the chronic sequelae of stroke may be ratcheting-up a myelin repair pathway, and that the consequent increase in BACE1 could be causing an inadvertent cleavage of its alternative substrate, AβPP, resulting in greater Aβ seeding and pathogenesis.
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17
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Spatial Dynamics of Vascular and Biochemical Injury in Rat Hippocampus Following Striatal Injury and Aβ Toxicity. Mol Neurobiol 2018; 56:2714-2727. [DOI: 10.1007/s12035-018-1225-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 07/05/2018] [Indexed: 01/09/2023]
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18
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Tariq S, d’Esterre CD, Sajobi TT, Smith EE, Longman RS, Frayne R, Coutts SB, Forkert ND, Barber PA. A longitudinal magnetic resonance imaging study of neurodegenerative and small vessel disease, and clinical cognitive trajectories in non demented patients with transient ischemic attack: the PREVENT study. BMC Geriatr 2018; 18:163. [PMID: 30012102 PMCID: PMC6048817 DOI: 10.1186/s12877-018-0858-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 07/09/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Late-life cognitive decline, caused by progressive neuronal loss leading to brain atrophy years before symptoms are detected, is expected to double in Canada over the next two decades. Cognitive impairment in late life is attributed to vascular and lifestyle related risk factors in mid-life in a substantial proportion of cases (50%), thereby providing an opportunity for effective prevention of cognitive decline if incipient disease is detected earlier. Patients presenting with transient ischemic attack (TIA) commonly display some degree of cognitive impairment and are at a 4-fold increased risk of dementia. In the Predementia Neuroimaging of Transient Ischemic Attack (PREVENT) study, we will address what disease processes (i.e., Alzheimer's vs. vascular disease) lead to neurodegeneration, brain atrophy, and cognitive decline, and whether imaging measurements of brain iron accumulation using quantitative susceptibility mapping predicts subsequent brain atrophy and cognitive decline. METHODS A total of 440 subjects will be recruited for this study with 220 healthy subjects and 220 TIA patients. Early Alzheimer's pathology will be determined by cerebrospinal fluid samples (including tau, a marker of neuronal injury, and amyloid β1-42) and by MR measurements of iron accumulation, a marker for Alzheimer's-related neurodegeneration. Small vessel disease will be identified by changes in white matter lesion volume. Predictors of advanced rates of cerebral and hippocampal atrophy at 1 and 3 years will include in vivo Alzheimer's disease pathology markers, and MRI measurements of brain iron accumulation and small vessel disease. Clinical and cognitive function will be assessed annually post-baseline for a period of 5-years using a clinical questionnaire and a battery of neuropsychological tests, respectively. DISCUSSION The PREVENT study expects to demonstrate that TIA patients have increased early progressive rates of cerebral brain atrophy after TIA, before cognitive decline can be clinically detected. By developing and optimizing high-level machine learning models based on clinical data, image-based (quantitative susceptibility mapping, regional brain, and white matter lesion volumes) features, and cerebrospinal fluid biomarkers, PREVENT will provide a timely opportunity to identify individuals at greatest risk of late-life cognitive decline early in the course of disease, supporting future therapeutic strategies for the promotion of healthy aging.
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Affiliation(s)
- Sana Tariq
- Calgary Stroke Program, Department of Clinical Neurosciences, Foothills Medical Centre, 1403 - 29 Street NW, Calgary, AB Canada
- Seaman Family MR Center, Foothills Medical Centre, 1403 29th Street NW, Calgary, AB Canada
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, 3330 Hospital Drive NW, Calgary, AB T2N 4N1 Canada
| | - Christopher D. d’Esterre
- Calgary Stroke Program, Department of Clinical Neurosciences, Foothills Medical Centre, 1403 - 29 Street NW, Calgary, AB Canada
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, 3330 Hospital Drive NW, Calgary, AB T2N 4N1 Canada
| | - Tolulope T. Sajobi
- Seaman Family MR Center, Foothills Medical Centre, 1403 29th Street NW, Calgary, AB Canada
- Department of Community Health Sciences & O’Brien Institute for Public Health, University of Calgary, 3280 Hospital Drive NW, Calgary, AB Canada
| | - Eric E. Smith
- Calgary Stroke Program, Department of Clinical Neurosciences, Foothills Medical Centre, 1403 - 29 Street NW, Calgary, AB Canada
- Seaman Family MR Center, Foothills Medical Centre, 1403 29th Street NW, Calgary, AB Canada
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, 3330 Hospital Drive NW, Calgary, AB T2N 4N1 Canada
| | - Richard Stewart Longman
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, 3330 Hospital Drive NW, Calgary, AB T2N 4N1 Canada
| | - Richard Frayne
- Seaman Family MR Center, Foothills Medical Centre, 1403 29th Street NW, Calgary, AB Canada
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, 3330 Hospital Drive NW, Calgary, AB T2N 4N1 Canada
- Department of Radiology and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB Canada
| | - Shelagh B. Coutts
- Calgary Stroke Program, Department of Clinical Neurosciences, Foothills Medical Centre, 1403 - 29 Street NW, Calgary, AB Canada
- Seaman Family MR Center, Foothills Medical Centre, 1403 29th Street NW, Calgary, AB Canada
- Department of Community Health Sciences & O’Brien Institute for Public Health, University of Calgary, 3280 Hospital Drive NW, Calgary, AB Canada
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, 3330 Hospital Drive NW, Calgary, AB T2N 4N1 Canada
| | - Nils D. Forkert
- Seaman Family MR Center, Foothills Medical Centre, 1403 29th Street NW, Calgary, AB Canada
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, 3330 Hospital Drive NW, Calgary, AB T2N 4N1 Canada
- Department of Radiology and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB Canada
| | - Philip A. Barber
- Calgary Stroke Program, Department of Clinical Neurosciences, Foothills Medical Centre, 1403 - 29 Street NW, Calgary, AB Canada
- Seaman Family MR Center, Foothills Medical Centre, 1403 29th Street NW, Calgary, AB Canada
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, 3330 Hospital Drive NW, Calgary, AB T2N 4N1 Canada
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19
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Dipyridamole plus Triflusal versus Triflusal Alone in Infarct Reduction after Middle Cerebral Artery Occlusion. J Stroke Cerebrovasc Dis 2018; 27:1283-1287. [DOI: 10.1016/j.jstrokecerebrovasdis.2017.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 11/16/2017] [Accepted: 12/11/2017] [Indexed: 01/26/2023] Open
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20
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Amtul Z, Hill DJ, Arany EJ, Cechetto DF. Altered Insulin/Insulin-Like Growth Factor Signaling in a Comorbid Rat model of Ischemia and β-Amyloid Toxicity. Sci Rep 2018; 8:5136. [PMID: 29572520 PMCID: PMC5865153 DOI: 10.1038/s41598-018-22985-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/06/2018] [Indexed: 02/06/2023] Open
Abstract
Ischemic stroke and diabetes are vascular risk factors for the development of impaired memory such as dementia and/or Alzheimer's disease. Clinical studies have demonstrated that minor striatal ischemic lesions in combination with β-amyloid (Aβ) load are critical in generating cognitive deficits. These cognitive deficits are likely to be associated with impaired insulin signaling. In this study, we examined the histological presence of insulin-like growth factor-I (IGF-1) and insulin receptor substrate (IRS-1) in anatomically distinct brain circuits compared with morphological brain damage in a co-morbid rat model of striatal ischemia (ET1) and Aβ toxicity. The results demonstrated a rapid increase in the presence of IGF-1 and IRS-1 immunoreactive cells in Aβ + ET1 rats, mainly in the ipsilateral striatum and distant regions with synaptic links to the striatal lesion. These regions included subcortical white matter, motor cortex, thalamus, dentate gyrus, septohippocampal nucleus, periventricular region and horizontal diagonal band of Broca in the basal forebrain. The alteration in IGF-1 and IRS-1 presence induced by ET1 or Aβ rats alone was not severe enough to affect the entire brain circuit. Understanding the causal or etiologic interaction between insulin and IGF signaling and co-morbidity after ischemia and Aβ toxicity will help design more effective therapeutics.
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Affiliation(s)
- Zareen Amtul
- Department of Anatomy and Cell Biology, University of Western Ontario, London, N6A 5C1, Canada.
| | - David J Hill
- Departments of Medicine, Physiology and Pharmacology, and Pediatrics, University of Western Ontario, London, N6A 5C1, Canada
- Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
| | - Edith J Arany
- Department of Pathology and Laboratory Medicine, University of Western Ontario, London, N6A 5C1, Canada
| | - David F Cechetto
- Department of Anatomy and Cell Biology, University of Western Ontario, London, N6A 5C1, Canada
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21
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Amtul Z, Yang J, Nikolova S, Lee TY, Bartha R, Cechetto DF. The Dynamics of Impaired Blood-Brain Barrier Restoration in a Rat Model of Co-morbid Injury. Mol Neurobiol 2018; 55:8071-8083. [PMID: 29508280 DOI: 10.1007/s12035-018-0904-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/10/2018] [Indexed: 12/31/2022]
Abstract
Defect in brain microperfusion is increasingly recognized as an antecedent event to Alzheimer's disease (AD) and ischemia. Nevertheless, studies on the role of impaired microperfusion as a pathological trigger to neuroinflammation, Aβ deposition as well as blood-brain barrier (BBB) disruption, and the etiological link between AD and ischemia are lacking. In this study, we employ in vivo sequential magnetic resonance imaging (MRI) and computed tomography (CT) imaging in a co-morbid rat model of β-amyloid toxicity (Aβ) and ischemia (ET1) with subsequent histopathology of striatal lesion core and penumbra at 1, 7, and 28 days post injury. Within 24 h, cerebral injury resulted in increased BBB permeability due to the dissolution of β-dystroglycan (β-DG) and basement membrane laminin by active matrix metalloproteinase9 (MMP9). As a result, net flow of circulating IgG down a hydrostatic gradient into the parenchyma led to vasogenic edema and impaired perfusion, thus increasing the apparent hyperintensity in true fast imaging with steady-state free precession (true FISP) imaging and acute hypoperfusion in CT. This was followed by a slow recruitment of reactive astroglia to the affected brain and depolarization of aquaporin4 (AQP4) expression resulting in cytotoxic edema-in an attempt to resolve vasogenic edema. On d28, functional BBB was restored in ET1 rats as observed by astrocytic MMP9 release, β-DG stabilization, and new vessel formation. This was confirmed by reduced hyperintensity on true FISP imaging and normalized cerebral blood flow in CT. While, Aβ toxicity alone was not detrimental enough, Aβ+ET1 rats showed delayed differential expression of MMP9, late recruitment of astroglial cells, protracted loss of AQP4 depolarization, and thus delayed BBB restoration and cerebral perfusion.
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Affiliation(s)
- Zareen Amtul
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada.
| | - Jun Yang
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Simona Nikolova
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Ting-Yim Lee
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Robert Bartha
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada.,Department of Medical Biophysics, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - David F Cechetto
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada
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22
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Freeze WM, Jacobs HIL, Gronenschild EH, Jansen JFA, Burgmans S, Aalten P, Clerx L, Vos SJ, van Buchem MA, Barkhof F, van der Flier WM, Verbeek MM, Rikkert MO, Backes WH, Verhey FR. White Matter Hyperintensities Potentiate Hippocampal Volume Reduction in Non-Demented Older Individuals with Abnormal Amyloid-β. J Alzheimers Dis 2018; 55:333-342. [PMID: 27662299 DOI: 10.3233/jad-160474] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cerebral small vessel disease (cSVD) and amyloid-β (Aβ) deposition often co-exist in (prodromal) dementia, and both types of pathology have been associated with neurodegeneration. We examined whether cSVD and Aβ have independent or interactive effects on hippocampal volume (HV) in a memory clinic population. We included 87 individuals with clinical diagnoses of Alzheimer's disease (AD) (n = 24), mild cognitive impairment (MCI) (n = 26), and subjective cognitive complaints (SCC) (n = 37). cSVD magnetic resonance imaging markers included white matter hyperintensity (WMH) volume, lacunar infarct presence, and microbleed presence. Aβ pathology was assessed as cerebrospinal fluid-derived Aβ1 - 42 levels and dichotomized into normal or abnormal, and HV was determined by manual volumetric measurements. A linear hierarchical regression approach was applied for the detection of additive or interaction effects between cSVD and Aβ on HV in the total participant group (n = 87) and in the non-demented group (including SCC and MCI individuals only, n = 63). The results revealed that abnormal Aβ and lacunar infarct presence were independently associated with lower HV in the non-demented individuals. Interestingly, Aβ and WMH pathology interacted in the non-demented individuals, such that WMH had a negative effect on HV in individuals with abnormal CSF Aβ42 levels, but not in individuals with normal CSF Aβ42 levels. These associations were not present when individuals with AD were included in the analyses. Our observations suggest that relatively early on in the disease process older individuals with abnormal Aβ levels are at an increased risk of accelerated disease progression when concomitant cSVD is present.
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Affiliation(s)
- Whitney M Freeze
- Department of Psychiatry and Neuropsychology, Maastricht University, School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht, The Netherlands.,Department of Radiology & Nuclear Medicine, Maastricht University Medical Center, School for Mental Health and Neuroscience, Maastricht, The Netherlands
| | - Heidi I L Jacobs
- Department of Psychiatry and Neuropsychology, Maastricht University, School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht, The Netherlands
| | - Ed H Gronenschild
- Department of Psychiatry and Neuropsychology, Maastricht University, School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht, The Netherlands
| | - Jacobus F A Jansen
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Center, School for Mental Health and Neuroscience, Maastricht, The Netherlands
| | - Saartje Burgmans
- Department of Psychiatry and Neuropsychology, Maastricht University, School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht, The Netherlands
| | - Pauline Aalten
- Department of Psychiatry and Neuropsychology, Maastricht University, School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht, The Netherlands
| | - Lies Clerx
- Department of Psychiatry and Neuropsychology, Maastricht University, School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht, The Netherlands
| | - Stephanie J Vos
- Department of Psychiatry and Neuropsychology, Maastricht University, School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht, The Netherlands
| | - Mark A van Buchem
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Frederik Barkhof
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.,Institutes of Neurology and Healthcare Engineering, University College Lodon, London, UK
| | | | - Marcel M Verbeek
- Departments of Neurology and Laboratory Medicine, Radboud University Medical Center Nijmegen, Donders Institute for Brain, Cognition and Behaviour, and Radboud Alzheimer Center, Nijmegen, The Netherlands
| | - Marcel Olde Rikkert
- Department of Geriatric Medicine, Radboud University Medical Center Nijmegen, Donders Institute for Brain, Cognition and Behaviour, and Radboud UMC, Alzheimer Center, Nijmegen, The Netherlands
| | - Walter H Backes
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Center, School for Mental Health and Neuroscience, Maastricht, The Netherlands
| | - Frans R Verhey
- Department of Psychiatry and Neuropsychology, Maastricht University, School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht, The Netherlands
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Michalski D, Hofmann S, Pitsch R, Grosche J, Härtig W. Neurovascular Specifications in the Alzheimer-Like Brain of Mice Affected by Focal Cerebral Ischemia: Implications for Future Therapies. J Alzheimers Dis 2017; 59:655-674. [DOI: 10.3233/jad-170185] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | - Sarah Hofmann
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Roman Pitsch
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | | | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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24
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Levit A, Regis AM, Garabon JR, Oh SH, Desai SJ, Rajakumar N, Hachinski V, Agca Y, Agca C, Whitehead SN, Allman BL. Behavioural inflexibility in a comorbid rat model of striatal ischemic injury and mutant hAPP overexpression. Behav Brain Res 2017; 333:267-275. [PMID: 28693862 DOI: 10.1016/j.bbr.2017.07.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 06/22/2017] [Accepted: 07/06/2017] [Indexed: 01/04/2023]
Abstract
Alzheimer disease (AD) and stroke coexist and interact; yet how they interact is not sufficiently understood. Both AD and basal ganglia stroke can impair behavioural flexibility, which can be reliably modeled in rats using an established operant based set-shifting test. Transgenic Fischer 344-APP21 rats (TgF344) overexpress pathogenic human amyloid precursor protein (hAPP) but do not spontaneously develop overt pathology, hence TgF344 rats can be used to model the effect of vascular injury in the prodromal stages of Alzheimer disease. We demonstrate that the injection of endothelin-1 (ET1) into the dorsal striatum of TgF344 rats (Tg-ET1) produced an exacerbation of behavioural inflexibility with a behavioural phenotype that was distinct from saline-injected wildtype & TgF344 rats as well as ET1-injected wildtype rats (Wt-ET1). In addition to profiling the types of errors made, interpolative modeling using logistic exposure-response regression provided an informative analysis of the timing and efficiency of behavioural flexibility. During set-shifting, Tg-ET1 committed fewer perseverative errors than Wt-ET1. However, Tg-ET1 committed significantly more regressive errors and had a less efficient strategy change than all other groups. Thus, behavioural flexibility was more vulnerable to striatal ischemic injury in TgF344 rats.
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Affiliation(s)
- Alexander Levit
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London ON, Canada
| | - Aaron M Regis
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London ON, Canada
| | - Jessica R Garabon
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London ON, Canada
| | - Seung-Hun Oh
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London ON, Canada
| | - Sagar J Desai
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London ON, Canada
| | - Nagalingam Rajakumar
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London ON, Canada
| | - Vladimir Hachinski
- Department of Clinical Neurological Sciences, University Hospital, Western University, London, ON, Canada
| | - Yuksel Agca
- Department of Veterinary Pathobiology, University of Missouri College of Veterinary Medicine, Columbia, MO, USA
| | - Cansu Agca
- Department of Veterinary Pathobiology, University of Missouri College of Veterinary Medicine, Columbia, MO, USA
| | - Shawn N Whitehead
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London ON, Canada; Department of Clinical Neurological Sciences, University Hospital, Western University, London, ON, Canada.
| | - Brian L Allman
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, Western University, London ON, Canada.
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25
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Hefter D, Draguhn A. APP as a Protective Factor in Acute Neuronal Insults. Front Mol Neurosci 2017; 10:22. [PMID: 28210211 PMCID: PMC5288400 DOI: 10.3389/fnmol.2017.00022] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 01/16/2017] [Indexed: 12/25/2022] Open
Abstract
Despite its key role in the molecular pathology of Alzheimer’s disease (AD), the physiological function of amyloid precursor protein (APP) is unknown. Increasing evidence, however, points towards a neuroprotective role of this membrane protein in situations of metabolic stress. A key observation is the up-regulation of APP following acute (stroke, cardiac arrest) or chronic (cerebrovascular disease) hypoxic-ischemic conditions. While this mechanism may increase the risk or severity of AD, APP by itself or its soluble extracellular fragment APPsα can promote neuronal survival. Indeed, different animal models of acute hypoxia-ischemia, traumatic brain injury (TBI) and excitotoxicity have revealed protective effects of APP or APPsα. The underlying mechanisms involve APP-mediated regulation of calcium homeostasis via NMDA receptors (NMDAR), voltage-gated calcium channels (VGCC) or internal calcium stores. In addition, APP affects the expression of survival- or apoptosis-related genes as well as neurotrophic factors. In this review, we summarize the current understanding of the neuroprotective role of APP and APPsα and possible implications for future research and new therapeutic strategies.
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Affiliation(s)
- Dimitri Hefter
- Institute of Physiology and Pathophysiology, Heidelberg UniversityHeidelberg, Germany; Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg UniversityMannheim, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, Heidelberg University Heidelberg, Germany
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The neuroprotective compound P7C3-A20 promotes neurogenesis and improves cognitive function after ischemic stroke. Exp Neurol 2017; 290:63-73. [PMID: 28077334 DOI: 10.1016/j.expneurol.2017.01.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/05/2016] [Accepted: 01/06/2017] [Indexed: 12/18/2022]
Abstract
Ischemic stroke is a devastating condition with few therapeutic interventions available. The neuroprotective compound P7C3-A20 inhibits mature neuronal cell death while also increasing the net magnitude of postnatal neurogenesis in models of neurodegeneration and acute injury. P7C3 compounds enhance flux of nicotinamide adenine dinucleotide (NAD) in mammalian cells, a proposed therapeutic approach to treating cerebral ischemia. The effectiveness of P7C3-A20 treatment on chronic histopathological and behavioral outcomes and neurogenesis after ischemic stroke has not previously been established. Here, a transient middle cerebral artery occlusion in rats was followed by twice daily injection of P7C3-A20 or vehicle for 7days. P7C3-A20-treated rats performed significantly better than vehicle-treated controls in sensorimotor cylinder and grid-walk tasks, and in a chronic test of spatial learning and memory. These behavioral improvements with P7C3-A20 treatment were correlated with significantly decreased cortical and hippocampal atrophy, and associated with increased neurogenesis in the subventricular zone and hippocampal dentate gyrus subgranular zone. Furthermore, cerebral ischemia significantly reduced NAD in the cortex but P7C3-A20 treatment restored NAD to sham levels. Thus, P7C3-A20 treatment mitigates neurodegeneration and augments repair in the brain after focal ischemia, which translates into chronic behavioral improvement. This suggests a new therapeutic approach of using P7C3 compounds to safely augment NAD and thereby promote two independent processes critical to protecting the brain from ischemic stroke: mature neuron survival and postnatal neurogenesis throughout the post-ischemic brain.
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Vitamin D 3 protects against Aβ peptide cytotoxicity in differentiated human neuroblastoma SH- SY5Y cells: A role for S1P1/p38MAPK/ATF4 axis. Neuropharmacology 2017; 116:328-342. [PMID: 28077289 DOI: 10.1016/j.neuropharm.2017.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/23/2016] [Accepted: 01/05/2017] [Indexed: 02/06/2023]
Abstract
Besides its classical function of bone metabolism regulation, 1alpha, 25-dihydroxyvitamin D3 (1,25(OH)2D3), acts on a variety of tissues including the nervous system, where the hormone plays an important role as neuroprotective, antiproliferating and differentiating agent. Sphingolipids are bioactive lipids that play critical and complex roles in regulating cell fate. In the present paper we have investigated whether sphingolipids are involved in the protective action of 1,25(OH)2D3. We have found that 1,25(OH)2D3 prevents amyloid-β peptide (Aβ(1-42)) cytotoxicity both in differentiated SH-SY5Y human neuroblastoma cells and in vivo. In differentiated SH-SY5Y cells, Aβ(1-42) strongly reduces the sphingosine-1-phosphate (S1P)/ceramide (Cer) ratio while 1,25(OH)2D3 partially reverts this effect. 1,25(OH)2D3 reverts also the Aβ(1-42)-induced reduction of sphingosine kinase activity. We have also studied the crosstalk between 1,25(OH)2D3 and S1P signaling pathways downstream to the activation of S1P receptor subtype S1P1. Notably, we found that 1,25(OH)2D3 prevents the reduction of S1P1 expression promoted by Aβ(1-42) and thereby it modulates the downstream signaling leading to ER stress damage (p38MAPK/ATF4). Similar effects were observed by using ZK191784. In addition, chronic treatment with 1,25(OH)2D3 protects from aggregated Aβ(1-42)-induced damage in the CA1 region of the rat hippocampus and promotes cell proliferation in the hippocampal dentate gyrus of adult mice. In conclusion, these results represent the first evidence of the role of 1,25(OH)2D3 and its structural analogue ZK191784 in counteracting the Aβ(1-42) peptide-induced toxicity through the modulation of S1P/S1P1/p38MAPK/ATF4 pathway in differentiated SH-SY5Y cells.
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28
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Härtig W, Appel S, Suttkus A, Grosche J, Michalski D. Abolished perineuronal nets and altered parvalbumin-immunoreactivity in the nucleus reticularis thalami of wildtype and 3xTg mice after experimental stroke. Neuroscience 2016; 337:66-87. [PMID: 27634771 DOI: 10.1016/j.neuroscience.2016.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/18/2016] [Accepted: 09/03/2016] [Indexed: 12/14/2022]
Abstract
Treatment strategies for ischemic stroke are still limited, since numerous attempts were successful only in preclinical research but failed under clinical condition. To overcome this translational roadblock, clinical relevant stroke models should consider co-morbidities, age-related effects and the complex neurovascular unit (NVU) concept. The NVU includes neurons, vessels and glial cells with astrocytic endfeet in close relation to the extracellular matrix (ECM). However, the role of the ECM after stroke-related tissue damage is poorly understood and mostly neglected for treatment strategies. This study is focused on alterations of perineuronal nets (PNs) as ECM constituents and parvalbumin-containing GABAergic neurons in mice with emphasis on the nucleus reticularis thalami (NRT) in close proximity to the ischemic lesion as induced by a filament-based stroke model. One day after ischemia onset, immunofluorescence-based quantitative analyses revealed drastically declined PNs in the ischemia-affected NRT from 3- and 12-month-old wildtype and co-morbid triple-transgenic (3xTg) mice with Alzheimer-like alterations. Parvalbumin-positive cells decreased numerically in the ischemia-affected NRT, while staining intensity did not differ between the affected and non-affected hemisphere. Additional qualitative analyses demonstrated ischemia-induced loss of PNs and allocated neuropil ECM immunoreactive for aggrecan and neurocan, and impaired immunoreactivity for calbindin, the potassium channel subunit Kv3.1b and the glutamate decarboxylase isoforms GAD65 and GAD67 in the NRT. In conclusion, these data confirm PNs as highly sensitive constituents of the ECM along with impaired neuronal integrity of GABAergic neurons. Therefore, specific targeting of ECM components might appear as a promising strategy for future treatment strategies in stroke.
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Affiliation(s)
- Wolfgang Härtig
- Paul Flechsig Institute for Brain Research University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany.
| | - Simon Appel
- Paul Flechsig Institute for Brain Research University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany
| | - Anne Suttkus
- Paul Flechsig Institute for Brain Research University of Leipzig, Liebigstr. 19, 04103 Leipzig, Germany; Department of Pediatric Surgery, University Hospital Leipzig, Liebigstr. 20 A, 04103 Leipzig, Germany
| | - Jens Grosche
- Effigos GmbH, Am Deutschen Platz 4, 04103 Leipzig, Germany
| | - Dominik Michalski
- Department of Neurology, University of Leipzig, Liebigstr. 20, 04103 Leipzig, Germany
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29
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Deibel S, Weishaupt N, Regis A, Hong N, Keeley R, Balog R, Bye C, Himmler S, Whitehead S, McDonald R. Subtle learning and memory impairment in an idiopathic rat model of Alzheimer's disease utilizing cholinergic depletions and β-amyloid. Brain Res 2016; 1646:12-24. [DOI: 10.1016/j.brainres.2016.05.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 05/16/2016] [Accepted: 05/17/2016] [Indexed: 02/02/2023]
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30
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Peng CY, Chen YC, Cui Y, Zhao DL, Jiao Y, Tang TY, Ju S, Teng GJ. Regional Coherence Alterations Revealed by Resting-State fMRI in Post-Stroke Patients with Cognitive Dysfunction. PLoS One 2016; 11:e0159574. [PMID: 27454170 PMCID: PMC4959733 DOI: 10.1371/journal.pone.0159574] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/04/2016] [Indexed: 11/19/2022] Open
Abstract
Objectives Post-stroke cognitive dysfunction greatly influences patients’ quality of life after stroke. However, its neurophysiological basis remains unknown. This study utilized resting-state functional magnetic resonance imaging (fMRI) to investigate the alterations in regional coherence in patients after subcortical stroke. Methods Resting-state fMRI measurements were acquired from 16 post-stroke patients with poor cognitive function (PSPC), 16 post-stroke patients with good cognitive function (PSGC) and 30 well-matched healthy controls (HC). Regional homogeneity (ReHo) was used to detect alterations in regional coherence. Abnormalities in regional coherence correlated with scores on neuropsychological scales. Results Compared to the HC and the PSGC, the PSPC showed remarkably decreased ReHo in the bilateral anterior cingulate cortex and the left posterior cingulate cortex/precuneus. ReHo in the bilateral anterior cingulate cortex positively correlated with the scores on the Symbol Digit Modalities Test (r = 0.399, P = 0.036) and the Complex Figure Test-delayed recall subtest (r = 0.397, P = 0.036) in all post-stroke patients. Moreover, ReHo in the left posterior cingulate cortex/precuneus positively correlated with the scores on the Forward Digit Span Test (r = 0.485, P = 0.009) in all post-stroke patients. Conclusions Aberrant regional coherence was observed in the anterior and posterior cingulate cortices in post-stroke patients with cognitive dysfunction. ReHo could represent a promising indicator of neurobiological deficiencies in post-stroke patients.
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Affiliation(s)
- Cheng-Yu Peng
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Medical School of Southeast University, Nanjing, Jiangsu, China
- Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Yu-Chen Chen
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Ying Cui
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Medical School of Southeast University, Nanjing, Jiangsu, China
- Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Deng-Ling Zhao
- Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Yun Jiao
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Tian-Yu Tang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Shenghong Ju
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Medical School of Southeast University, Nanjing, Jiangsu, China
- Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu, China
| | - Gao-Jun Teng
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Medical School of Southeast University, Nanjing, Jiangsu, China
- Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu, China
- * E-mail:
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31
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Nell HJ, Au JL, Giordano CR, Terlecky SR, Walton PA, Whitehead SN, Cechetto DF. Targeted Antioxidant, Catalase-SKL, Reduces Beta-Amyloid Toxicity in the Rat Brain. Brain Pathol 2016; 27:86-94. [PMID: 26919450 DOI: 10.1111/bpa.12368] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 02/08/2016] [Indexed: 12/21/2022] Open
Abstract
Accumulation of beta-amyloid (Aβ) in the brain has been implicated as a major contributor to the cellular pathology and cognitive impairment observed in Alzheimer's disease. Beta-amyloid may exert its toxic effects by increasing reactive oxygen species and neuroinflammation in the brain. This study set out to investigate whether a genetically engineered derivative of the peroxisomal antioxidant enzyme catalase (CAT-SKL), is able to reduce the toxicity induced by intracerebroventricular injection of Aβ25-35 in the mature rat brain. Histopathological and immunohistochemical analyses were used to evaluate neuroinflammation, and neuronal loss. Spatial learning and reference memory was assessed using the Morris water maze. CAT-SKL treatment was able to reduce the pathology induced by Aβ25-35 toxicity by significantly decreasing microglia activation in the basal forebrain and thalamus, and reducing cholinergic loss in the basal forebrain. Aβ25-35 animals showed deficits in long-term reference memory in the Morris water maze, while Aβ25-35 animals treated with CAT-SKL did not demonstrate long-term memory impairments. This preclinical data provides support for the use of CAT-SKL in reducing neuroinflammation and long-term reference memory deficits induced by Aβ25-35.
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Affiliation(s)
- Hayley J Nell
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Jennifer L Au
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Courtney R Giordano
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, 48201
| | - Stanley R Terlecky
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, 48201
| | - Paul A Walton
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - Shawn N Whitehead
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada
| | - David F Cechetto
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada
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32
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Gidyk DC, Deibel SH, Hong NS, McDonald RJ. Barriers to developing a valid rodent model of Alzheimer's disease: from behavioral analysis to etiological mechanisms. Front Neurosci 2015; 9:245. [PMID: 26283893 PMCID: PMC4518326 DOI: 10.3389/fnins.2015.00245] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/29/2015] [Indexed: 12/30/2022] Open
Abstract
Sporadic Alzheimer's disease (AD) is the most prevalent form of age-related dementia. As such, great effort has been put forth to investigate the etiology, progression, and underlying mechanisms of the disease. Countless studies have been conducted, however, the details of this disease remain largely unknown. Rodent models provide opportunities to investigate certain aspects of AD that cannot be studied in humans. These animal models vary from study to study and have provided some insight, but no real advancements in the prevention or treatment of the disease. In this Hypothesis and Theory paper, we discuss what we perceive as barriers to impactful discovery in rodent AD research and we offer potential solutions for moving forward. Although no single model of AD is capable of providing the solution to the growing epidemic of the disease, we encourage a comprehensive approach that acknowledges the complex etiology of AD with the goal of enhancing the bidirectional translatability from bench to bedside and vice versa.
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Affiliation(s)
- Darryl C. Gidyk
- *Correspondence: Darryl C. Gidyk, Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 6W4, Canada
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Keeley R, Bye C, Trow J, McDonald R. Strain and sex differences in brain and behaviour of adult rats: Learning and memory, anxiety and volumetric estimates. Behav Brain Res 2015; 288:118-31. [DOI: 10.1016/j.bbr.2014.10.039] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 10/20/2014] [Accepted: 10/24/2014] [Indexed: 12/13/2022]
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34
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Caughlin S, Hepburn JD, Park DH, Jurcic K, Yeung KKC, Cechetto DF, Whitehead SN. Increased Expression of Simple Ganglioside Species GM2 and GM3 Detected by MALDI Imaging Mass Spectrometry in a Combined Rat Model of Aβ Toxicity and Stroke. PLoS One 2015; 10:e0130364. [PMID: 26086081 PMCID: PMC4473074 DOI: 10.1371/journal.pone.0130364] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 05/18/2015] [Indexed: 01/14/2023] Open
Abstract
The aging brain is often characterized by the presence of multiple comorbidities resulting in synergistic damaging effects in the brain as demonstrated through the interaction of Alzheimer's disease (AD) and stroke. Gangliosides, a family of membrane lipids enriched in the central nervous system, may have a mechanistic role in mediating the brain's response to injury as their expression is altered in a number of disease and injury states. Matrix-Assisted Laser Desorption Ionization (MALDI) Imaging Mass Spectrometry (IMS) was used to study the expression of A-series ganglioside species GD1a, GM1, GM2, and GM3 to determine alteration of their expression profiles in the presence of beta-amyloid (Aβ) toxicity in addition to ischemic injury. To model a stroke, rats received a unilateral striatal injection of endothelin-1 (ET-1) (stroke alone group). To model Aβ toxicity, rats received intracerebralventricular (i.c.v.) injections of the toxic 25-35 fragment of the Aβ peptide (Aβ alone group). To model the combination of Aβ toxicity with stroke, rats received both the unilateral ET-1 injection and the bilateral icv injections of Aβ25-35 (combined Aβ/ET-1 group). By 3 d, a significant increase in the simple ganglioside species GM2 was observed in the ischemic brain region of rats who received a stroke (ET-1), with or without Aβ. By 21 d, GM2 levels only remained elevated in the combined Aβ/ET-1 group. GM3 levels however demonstrated a different pattern of expression. By 3 d GM3 was elevated in the ischemic brain region only in the combined Aβ/ET-1 group. By 21 d, GM3 was elevated in the ischemic brain region in both stroke alone and Aβ/ET-1 groups. Overall, results indicate that the accumulation of simple ganglioside species GM2 and GM3 may be indicative of a mechanism of interaction between AD and stroke.
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Affiliation(s)
- Sarah Caughlin
- Dept. Anatomy and Cell Biology, Western University, London, ON, N6A 5C1, Canada
| | - Jeffrey D. Hepburn
- Dept. Anatomy and Cell Biology, Western University, London, ON, N6A 5C1, Canada
| | - Dae Hee Park
- Dept. Anatomy and Cell Biology, Western University, London, ON, N6A 5C1, Canada
| | - Kristina Jurcic
- Dept. Chemistry and Dept. Biochemistry, Western University, London, ON, N6A 5C1, Canada
| | - Ken K.-C. Yeung
- Dept. Chemistry and Dept. Biochemistry, Western University, London, ON, N6A 5C1, Canada
| | - David F. Cechetto
- Dept. Anatomy and Cell Biology, Western University, London, ON, N6A 5C1, Canada
| | - Shawn N. Whitehead
- Dept. Anatomy and Cell Biology, Western University, London, ON, N6A 5C1, Canada
- Dept. Clinical Neurological Sciences, London Health Sciences Centre, University of Western Ontario, London, ON, N6A 5A5, Canada
- * E-mail:
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Keeley RJ, McDonald RJ. Part III: Principal component analysis: bridging the gap between strain, sex and drug effects. Behav Brain Res 2015; 288:153-61. [PMID: 25813745 DOI: 10.1016/j.bbr.2015.03.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/08/2015] [Accepted: 03/12/2015] [Indexed: 01/07/2023]
Abstract
Previous work has identified the adolescent period as particularly sensitive to the short- and long-term effects of marijuana and its main psychoactive component Δ9-tetrahydrocannabinol (THC). However, other studies have identified certain backgrounds as more sensitive than others, including the sex of the individual or the strain of the rat used. Further, the effects of THC may be specific to certain behavioural tasks (e.g. measures of anxiety), and the consequences of THC are not seen equally across all behavioural measures. Here, data obtained from adolescent male and female Long-Evans and Wistar rats exposed to THC and tested as adults, which, using standard ANOVA testing, showed strain- and sex-specific effects of THC, was analyzed using principal component analysis (PCA). PCA allowed for the examination of the relative contribution of our variables of interest to the variance in the data obtained from multiple behavioural tasks, including the skilled reaching task, the Morris water task, the discriminative fear-conditioning to context task, the elevated plus maze task and the conditioned place preference task to a low dose of amphetamine, as well as volumetric estimates of brain volumes and cfos activation. We observed that early life experience accounted for a large proportion of variance across data sets, although its relative contribution varied across tasks. Additionally, THC accounted for a very small proportion of the variance across all behavioural tasks. We demonstrate here that by using PCA, we were able to describe the main variables of interest and demonstrate that THC exposure had a negligible effect on the variance in the data set.
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Affiliation(s)
- R J Keeley
- University of Lethbridge, 4001 University Drive, Lethbridge, AB T1K 3M4, Canada.
| | - R J McDonald
- University of Lethbridge, 4001 University Drive, Lethbridge, AB T1K 3M4, Canada
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Keeley R, Hong N, Fisher A, McDonald R. Co-morbid beta-amyloid toxicity and stroke produce impairments in an ambiguous context task in rats without any impairment in spatial working memory. Neurobiol Learn Mem 2015; 119:42-51. [DOI: 10.1016/j.nlm.2015.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 01/02/2015] [Accepted: 01/05/2015] [Indexed: 01/28/2023]
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Serum Aβ is predictive for short-term neurological deficits after acute ischemic stroke. Neurotox Res 2015; 27:292-9. [PMID: 25612546 DOI: 10.1007/s12640-015-9518-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 12/29/2014] [Accepted: 01/12/2015] [Indexed: 12/13/2022]
Abstract
Mounting evidence suggests that ischemic stroke (IS) is associated with Alzheimer's disease (AD). IS and vascular risk factors increase the risk for AD. However, whether AD pathologies exist in IS and the effects of these pathologies on stroke remain unknown. In the present study, we aimed to investigate the alterations of serum Aβ after acute IS (AIS), and its correlations with the neurological deficits, infarction volume, and site after stroke. AIS patients (n = 35) were recruited within 24 h of symptom onset. Age- and gender-matched AD patients (n = 48) and cognitively normal controls (NC, n = 37) were also enrolled. Serum Aβ40 and Aβ42 and the National Institute of Health Stroke Scale Score (NIHSS) were measured on day 1, 3, and 7 after stroke onset. We found that serum Aβ40 and Aβ42 levels were increased at day 1 and reached peak levels at day 3, and decreased to pre-stroke levels at day 7. Serum Aβ40 levels at day 1 were correlated with the NIHSS scores and infarction volume of AIS patients. Serum Aβ42 levels at day 1 were significantly higher in IS patients with dominant gray matter infarction. Serum Aβ40 levels at day 1 were predictive for NIHSS at day 7. Our results indicate that AIS can induce the generation of Aβ in the brain, which may in turn be involved in the pathogenesis of neurological deficits after stroke. Serum Aβ might be predictive for the short-term neurological deficits after AIS.
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Keeley RJ, Trow J, Bye C, McDonald RJ. Part II: Strain- and sex-specific effects of adolescent exposure to THC on adult brain and behaviour: Variants of learning, anxiety and volumetric estimates. Behav Brain Res 2015; 288:132-52. [PMID: 25591471 DOI: 10.1016/j.bbr.2015.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 12/31/2014] [Accepted: 01/02/2015] [Indexed: 12/20/2022]
Abstract
Marijuana is one of the most highly used psychoactive substances in the world, and its use typically begins during adolescence, a period of substantial brain development. Females across species appear to be more susceptible to the long-term consequences of marijuana use. Despite the identification of inherent differences between rat strains including measures of anatomy, genetics and behaviour, no studies to our knowledge have examined the long-term consequences of adolescent exposure to marijuana or its main psychoactive component, Δ(9)-tetrahydrocannabinol (THC), in males and females of two widely used rat strains: Long-Evans hooded (LER) and Wistar (WR) rats. THC was administered for 14 consecutive days following puberty onset, and once they reached adulthood, changes in behaviour and in the volume of associated brain areas were quantified. Rats were assessed in behavioural tests of motor, spatial and contextual learning, and anxiety. Some tasks showed effects of injection, since handled and vehicle groups were included as controls. Performance on all tasks, except motor learning, and the volume of associated brain areas were altered with injection or THC administration, although these effects varied by strain and sex group. Finally, analysis revealed treatment-specific correlations between performance and brain volumes. This study is the first of its kind to directly compare males and females of two rat strains for the long-term consequences of adolescent THC exposure. It highlights the importance of considering strain and identifies certain rat strains as susceptible or resilient to the effects of THC.
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Affiliation(s)
- R J Keeley
- University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 4N8, Canada.
| | - J Trow
- University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 4N8, Canada
| | - C Bye
- University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 4N8, Canada
| | - R J McDonald
- University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 4N8, Canada
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Nell HJ, Whitehead SN, Cechetto DF. Age-Dependent Effect of β-Amyloid Toxicity on Basal Forebrain Cholinergic Neurons and Inflammation in the Rat Brain. Brain Pathol 2014; 25:531-42. [PMID: 25187042 DOI: 10.1111/bpa.12199] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/27/2014] [Indexed: 01/08/2023] Open
Abstract
Beta-amyloid (Aβ) accumulation, neuroinflammation, basal forebrain cholinergic loss and hippocampal degeneration are well-described pathologies associated with Alzheimer's disease (AD). However, the role that age plays in the susceptibility of the brain to these AD pathologies and the relationships between them is still not well understood. This study investigated the age-related response to intracerebroventricular injection of Aβ(25-35) in 3-, 6- and 9-month-old rats. Aβ toxicity resulted in an age-related increase in cholinergic loss and microglial activation in the basal forebrain along with neuronal loss in the hippocampal CA3 subfield. Performance in the Morris water maze revealed impairments in long-term reference memory in 6-month-old Aβ administered animals, which was not seen in 3-month-old animals. These results support a role of Aβ administration in inducing age-dependent cholinergic loss and neuroinflammation, and additionally provide evidence for a more age-appropriate model of adult-onset Aβ toxicity demonstrating pathological changes that reflect the early stages of AD pathogenesis including neuroinflammation, cholinergic loss and beginning stages of memory impairment.
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Affiliation(s)
- Hayley Joy Nell
- Department of Anatomy & Cell Biology, Western University, London, ON, Canada
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Amtul Z, Whitehead SN, Keeley RJ, Bechberger J, Fisher AL, McDonald RJ, Naus CC, Munoz DG, Cechetto DF. Comorbid rat model of ischemia and β-amyloid toxicity: striatal and cortical degeneration. Brain Pathol 2014; 25:24-32. [PMID: 24725245 DOI: 10.1111/bpa.12149] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 04/02/2014] [Indexed: 12/23/2022] Open
Abstract
Levels of cerebral amyloid, presumably β-amyloid (Abeta), toxicity and the incidence of cortical and subcortical ischemia increases with age. However, little is known about the severe pathological condition and dementia that occur as a result of the comorbid occurrence of this vascular risk factor and Abeta toxicity. Clinical studies have indicated that small ischemic lesions in the striatum are particularly important in generating dementia in combination with minor amyloid lesions. These cognitive deficits are highly likely to be caused by changes in the cortex. In this study, we examined the viability and morphological changes in microglial and neuronal cells, gap junction proteins (connexin43) and neuritic/axonal retraction (Fer Kinase) in the striatum and cerebral cortex using a comorbid rat model of striatal injections of endothelin-1 (ET1) and Abeta toxicity. The results demonstrated ventricular enlargement, striatal atrophy, substantial increases in β-amyloid, ramified microglia and increases in neuritic retraction in the combined models of stroke and Abeta toxicity. Changes in connexin43 occurred equally in both groups of Abeta-treated rats, with and without focal ischemia. Although previous behavioral tests demonstrated impairment in memory and learning, the visual discrimination radial maze task did not show significant difference, suggesting the cognitive impairment in these models is not related to damage to the dorsolateral striatum. These results suggest an insight into the relationship between cortical/striatal atrophy, pathology and functional impairment.
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Affiliation(s)
- Zareen Amtul
- CIHR Group on Vascular Cognitive Impairment, Department of Anatomy and Cell Biology, Western University, London, ON, Canada
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