1
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Hojjati SH, Butler TA, Luchsinger JA, Benitez R, de Leon M, Nayak S, Razlighi QR, Chiang GC. Increased between-network connectivity: A risk factor for tau elevation and disease progression. Neurosci Lett 2024; 840:137943. [PMID: 39153526 DOI: 10.1016/j.neulet.2024.137943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 06/26/2024] [Accepted: 08/14/2024] [Indexed: 08/19/2024]
Abstract
One of the pathologic hallmarks of Alzheimer's disease (AD) is neurofibrillary tau tangles. Despite our knowledge that tau typically initiates in the medial temporal lobe (MTL), the mechanisms driving tau to spread beyond MTL remain unclear. Emerging evidence reveals distinct patterns of functional connectivity change during aging and preclinical AD: while connectivity within-network decreases, connectivity between-network increases. Building upon increased between-network connectivity, our study hypothesizes that this increase may play a critical role in facilitating tau spread in early stages. We conducted a longitudinal study over two to three years intervals on a cohort of 46 healthy elderly participants (mean age 64.23 ± 3.15 years, 26 females). Subjects were examined clinically and utilizing advanced imaging techniques that included resting-state functional MRI (rs-fMRI), structural magnetic resonance imaging (MRI), and a second-generation positron emission tomography (PET) tau tracer, 18F-MK6240. Through unsupervised agglomerative clustering and increase in between-network connectivity, we successfully identified individuals at increased risk of future tau elevation and AD progression. Our analysis revealed that individuals with increased between-network connectivity are more likely to experience more future tau deposition, entorhinal cortex thinning, and lower selective reminding test (SRT) delayed scores. Additionally, in the limbic network, we found a strong association between tau progression and increased between-network connectivity, which was mainly driven by beta-amyloid (Aβ) positive participants. These findings provide evidence for the hypothesis that an increase in between-network connectivity predicts future tau deposition and AD progression, also enhancing our understanding of AD pathogenesis in the preclinical stages.
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Affiliation(s)
- Seyed Hani Hojjati
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States.
| | - Tracy A Butler
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - José A Luchsinger
- Department of Medicine, Columbia University Irving Medical Center, New York, NY, United States; Department of Epidemiology, Columbia University Irving Medical Center, New York, NY, United States
| | - Richard Benitez
- Department of Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Mony de Leon
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Siddharth Nayak
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Qolamreza R Razlighi
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Gloria C Chiang
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
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2
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Zeng X, Puonti O, Sayeed A, Herisse R, Mora J, Evancic K, Varadarajan D, Balbastre Y, Costantini I, Scardigli M, Ramazzotti J, DiMeo D, Mazzamuto G, Pesce L, Brady N, Cheli F, Saverio Pavone F, Hof PR, Frost R, Augustinack J, van der Kouwe A, Eugenio Iglesias J, Fischl B. Segmentation of supragranular and infragranular layers in ultra-high-resolution 7T ex vivo MRI of the human cerebral cortex. Cereb Cortex 2024; 34:bhae362. [PMID: 39264753 PMCID: PMC11391621 DOI: 10.1093/cercor/bhae362] [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: 03/08/2024] [Revised: 08/06/2024] [Accepted: 08/18/2024] [Indexed: 09/14/2024] Open
Abstract
Accurate labeling of specific layers in the human cerebral cortex is crucial for advancing our understanding of neurodevelopmental and neurodegenerative disorders. Building on recent advancements in ultra-high-resolution ex vivo MRI, we present a novel semi-supervised segmentation model capable of identifying supragranular and infragranular layers in ex vivo MRI with unprecedented precision. On a dataset consisting of 17 whole-hemisphere ex vivo scans at 120 $\mu $m, we propose a Multi-resolution U-Nets framework that integrates global and local structural information, achieving reliable segmentation maps of the entire hemisphere, with Dice scores over 0.8 for supra- and infragranular layers. This enables surface modeling, atlas construction, anomaly detection in disease states, and cross-modality validation while also paving the way for finer layer segmentation. Our approach offers a powerful tool for comprehensive neuroanatomical investigations and holds promise for advancing our mechanistic understanding of progression of neurodegenerative diseases.
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Affiliation(s)
- Xiangrui Zeng
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Oula Puonti
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Blegdamsvej 9, 2100 København, Denmark
| | - Areej Sayeed
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Rogeny Herisse
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Jocelyn Mora
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Kathryn Evancic
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Divya Varadarajan
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Yael Balbastre
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Irene Costantini
- National Institute of Optics (CNR-INO), National Research Council, Largo Enrico Fermi, 6, 50125 Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
- Department of Biology, University of Florence, P.za di San Marco, 4, 50121 Firenze FI, Italy
| | - Marina Scardigli
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
| | - Josephine Ramazzotti
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
| | - Danila DiMeo
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
| | - Giacomo Mazzamuto
- National Institute of Optics (CNR-INO), National Research Council, Largo Enrico Fermi, 6, 50125 Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, P.za di San Marco, 4, 50121 Firenze FI, Italy
| | - Luca Pesce
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
| | - Niamh Brady
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
| | - Franco Cheli
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
| | - Francesco Saverio Pavone
- National Institute of Optics (CNR-INO), National Research Council, Largo Enrico Fermi, 6, 50125 Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara, 1, 50019 Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, P.za di San Marco, 4, 50121 Firenze FI, Italy
| | - Patrick R Hof
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY 10029, USA
| | - Robert Frost
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Jean Augustinack
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - André van der Kouwe
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Juan Eugenio Iglesias
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Bruce Fischl
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St, Boston, MA 02129, USA
- Department of Radiology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
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3
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Kampmann M. Molecular and cellular mechanisms of selective vulnerability in neurodegenerative diseases. Nat Rev Neurosci 2024; 25:351-371. [PMID: 38575768 DOI: 10.1038/s41583-024-00806-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2024] [Indexed: 04/06/2024]
Abstract
The selective vulnerability of specific neuronal subtypes is a hallmark of neurodegenerative diseases. In this Review, I summarize our current understanding of the brain regions and cell types that are selectively vulnerable in different neurodegenerative diseases and describe the proposed underlying cell-autonomous and non-cell-autonomous mechanisms. I highlight how recent methodological innovations - including single-cell transcriptomics, CRISPR-based screens and human cell-based models of disease - are enabling new breakthroughs in our understanding of selective vulnerability. An understanding of the molecular mechanisms that determine selective vulnerability and resilience would shed light on the key processes that drive neurodegeneration and point to potential therapeutic strategies to protect vulnerable cell populations.
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Affiliation(s)
- Martin Kampmann
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
- Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, CA, USA.
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4
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Merenstein JL, Zhao J, Overson DK, Truong TK, Johnson KG, Song AW, Madden DJ. Depth- and curvature-based quantitative susceptibility mapping analyses of cortical iron in Alzheimer's disease. Cereb Cortex 2024; 34:bhad525. [PMID: 38185996 PMCID: PMC10839848 DOI: 10.1093/cercor/bhad525] [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: 09/20/2023] [Revised: 11/21/2023] [Accepted: 12/15/2023] [Indexed: 01/09/2024] Open
Abstract
In addition to amyloid beta plaques and neurofibrillary tangles, Alzheimer's disease (AD) has been associated with elevated iron in deep gray matter nuclei using quantitative susceptibility mapping (QSM). However, only a few studies have examined cortical iron, using more macroscopic approaches that cannot assess layer-specific differences. Here, we conducted column-based QSM analyses to assess whether AD-related increases in cortical iron vary in relation to layer-specific differences in the type and density of neurons. We obtained global and regional measures of positive (iron) and negative (myelin, protein aggregation) susceptibility from 22 adults with AD and 22 demographically matched healthy controls. Depth-wise analyses indicated that global susceptibility increased from the pial surface to the gray/white matter boundary, with a larger slope for positive susceptibility in the left hemisphere for adults with AD than controls. Curvature-based analyses indicated larger global susceptibility for adults with AD versus controls; the right hemisphere versus left; and gyri versus sulci. Region-of-interest analyses identified similar depth- and curvature-specific group differences, especially for temporo-parietal regions. Finding that iron accumulates in a topographically heterogenous manner across the cortical mantle may help explain the profound cognitive deterioration that differentiates AD from the slowing of general motor processes in healthy aging.
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Affiliation(s)
- Jenna L Merenstein
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC 27710, United States
| | - Jiayi Zhao
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC 27710, United States
| | - Devon K Overson
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC 27710, United States
- Medical Physics Graduate Program, Duke University, Durham, NC 27708, United States
| | - Trong-Kha Truong
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC 27710, United States
- Medical Physics Graduate Program, Duke University, Durham, NC 27708, United States
| | - Kim G Johnson
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, United States
| | - Allen W Song
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC 27710, United States
- Medical Physics Graduate Program, Duke University, Durham, NC 27708, United States
| | - David J Madden
- Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC 27710, United States
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, United States
- Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, United States
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5
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Ferré-González L, Balaguer Á, Roca M, Ftara A, Lloret A, Cháfer-Pericás C. Brain areas lipidomics in female transgenic mouse model of Alzheimer's disease. Sci Rep 2024; 14:870. [PMID: 38195731 PMCID: PMC10776612 DOI: 10.1038/s41598-024-51463-3] [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: 09/14/2023] [Accepted: 01/05/2024] [Indexed: 01/11/2024] Open
Abstract
Lipids are the major component of the brain with important structural and functional properties. Lipid disruption could play a relevant role in Alzheimer's disease (AD). Some brain lipidomic studies showed significant differences compared to controls, but few studies have focused on different brain areas related to AD. Furthermore, AD is more prevalent in females, but there is a lack of studies focusing on this sex. This work aims to perform a lipidomic study in selected brain areas (cerebellum, amygdala, hippocampus, entire cortex) from wild-type (WT, n = 10) and APPswe/PS1dE9 transgenic (TG, n = 10) female mice of 5 months of age, as a model of early AD, to identify alterations in lipid composition. A lipidomic mass spectrometry-based method was optimized and applied to brain tissue. As result, some lipids showed statistically significant differences between mice groups in cerebellum (n = 68), amygdala (n = 49), hippocampus (n = 48), and the cortex (n = 22). In addition, some lipids (n = 15) from the glycerolipid, phospholipid, and sphingolipid families were statistically significant in several brain areas simultaneously between WT and TG. A selection of lipid variables was made to develop a multivariate approach to assess their discriminant potential, showing high diagnostic indexes, especially in cerebellum and amygdala (sensitivity 70-100%, sensibility 80-100%).
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Affiliation(s)
- Laura Ferré-González
- Alzheimer's Disease Research Group, Health Research Institute La Fe, Avda de Fernando Abril Martorell, 106, 46026, Valencia, Spain
| | - Ángel Balaguer
- Faculty of Mathematics, University of Valencia, Valencia, Spain
| | - Marta Roca
- Analytical Unit, Health Research Institute La Fe, Valencia, Spain
| | | | - Ana Lloret
- Department of Physiology, Faculty of Medicine, University of Valencia, Health Research Institute INCLIVA, Valencia, Spain
| | - Consuelo Cháfer-Pericás
- Alzheimer's Disease Research Group, Health Research Institute La Fe, Avda de Fernando Abril Martorell, 106, 46026, Valencia, Spain.
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6
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Hojjati SH, Chiang GC, Butler TA, de Leon M, Gupta A, Li Y, Sabuncu MR, Feiz F, Nayak S, Shteingart J, Ozoria S, Gholipour Picha S, Stern Y, Luchsinger JA, Devanand DP, Razlighi QR. Remote Associations Between Tau and Cortical Amyloid-β Are Stage-Dependent. J Alzheimers Dis 2024; 98:1467-1482. [PMID: 38552116 DOI: 10.3233/jad-231362] [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] [Indexed: 04/20/2024]
Abstract
Background Histopathologic studies of Alzheimer's disease (AD) suggest that extracellular amyloid-β (Aβ) plaques promote the spread of neurofibrillary tau tangles. However, these two proteinopathies initiate in spatially distinct brain regions, so how they interact during AD progression is unclear. Objective In this study, we utilized Aβ and tau positron emission tomography (PET) scans from 572 older subjects (476 healthy controls (HC), 14 with mild cognitive impairment (MCI), 82 with mild AD), at varying stages of the disease, to investigate to what degree tau is associated with cortical Aβ deposition. Methods Using multiple linear regression models and a pseudo-longitudinal ordering technique, we investigated remote tau-Aβ associations in four pathologic phases of AD progression based on tau spread: 1) no-tau, 2) pre-acceleration, 3) acceleration, and 4) post-acceleration. Results No significant tau-Aβ association was detected in the no-tau phase. In the pre-acceleration phase, the earliest stage of tau deposition, associations emerged between regional tau in medial temporal lobe (MTL) (i.e., entorhinal cortex, parahippocampal gyrus) and cortical Aβ in lateral temporal lobe regions. The strongest tau-Aβ associations were found in the acceleration phase, in which tau in MTL regions was strongly associated with cortical Aβ (i.e., temporal and frontal lobes regions). Strikingly, in the post-acceleration phase, including 96% of symptomatic subjects, tau-Aβ associations were no longer significant. Conclusions The results indicate that associations between tau and Aβ are stage-dependent, which could have important implications for understanding the interplay between these two proteinopathies during the progressive stages of AD.
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Affiliation(s)
- Seyed Hani Hojjati
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Gloria C Chiang
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Tracy A Butler
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Mony de Leon
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Ajay Gupta
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Yi Li
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Mert R Sabuncu
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA
| | - Farnia Feiz
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Siddharth Nayak
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Jacob Shteingart
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Sindy Ozoria
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Saman Gholipour Picha
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Yaakov Stern
- Departments of Neurology, Psychiatry, GH Sergievsky Center, The Taub Institute for the Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
| | - José A Luchsinger
- Departments of Medicine and Epidemiology, Columbia University Irving Medical Center, New York, NY, USA
| | - Davangere P Devanand
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, USA
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
- Department of Psychiatry, New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, USA
| | - Qolamreza R Razlighi
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
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7
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Zeng X, Puonti O, Sayeed A, Herisse R, Mora J, Evancic K, Varadarajan D, Balbastre Y, Costantini I, Scardigli M, Ramazzotti J, DiMeo D, Mazzamuto G, Pesce L, Brady N, Cheli F, Pavone FS, Hof PR, Frost R, Augustinack J, van der Kouwe A, Iglesias JE, Fischl B. Segmentation of supragranular and infragranular layers in ultra-high resolution 7T ex vivo MRI of the human cerebral cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.06.570416. [PMID: 38106176 PMCID: PMC10723438 DOI: 10.1101/2023.12.06.570416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Accurate labeling of specific layers in the human cerebral cortex is crucial for advancing our understanding of neurodevelopmental and neurodegenerative disorders. Leveraging recent advancements in ultra-high resolution ex vivo MRI, we present a novel semi-supervised segmentation model capable of identifying supragranular and infragranular layers in ex vivo MRI with unprecedented precision. On a dataset consisting of 17 whole-hemisphere ex vivo scans at 120 μm, we propose a multi-resolution U-Nets framework (MUS) that integrates global and local structural information, achieving reliable segmentation maps of the entire hemisphere, with Dice scores over 0.8 for supra- and infragranular layers. This enables surface modeling, atlas construction, anomaly detection in disease states, and cross-modality validation, while also paving the way for finer layer segmentation. Our approach offers a powerful tool for comprehensive neuroanatomical investigations and holds promise for advancing our mechanistic understanding of progression of neurodegenerative diseases.
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Affiliation(s)
- Xiangrui Zeng
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Oula Puonti
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - Areej Sayeed
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Rogeny Herisse
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Jocelyn Mora
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Kathryn Evancic
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Divya Varadarajan
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Yael Balbastre
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Irene Costantini
- National Research Council - National Institute of Optics (CNR-INO), Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- Department of Biology, University of Florence, Italy
| | - Marina Scardigli
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
| | | | - Danila DiMeo
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
| | - Giacomo Mazzamuto
- National Research Council - National Institute of Optics (CNR-INO), Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Italy
| | - Luca Pesce
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
| | - Niamh Brady
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
| | - Franco Cheli
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
| | - Francesco Saverio Pavone
- National Research Council - National Institute of Optics (CNR-INO), Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Italy
| | - Patrick R. Hof
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Robert Frost
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Jean Augustinack
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - André van der Kouwe
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Juan Eugenio Iglesias
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
| | - Bruce Fischl
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Department of Radiology, Boston, MA, USA
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8
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Regulatory role of melatonin in Notch1 signaling pathway in cerebral cortex of Aβ 1-42-induced Alzheimer's disease rat model. Mol Biol Rep 2023; 50:2463-2469. [PMID: 36602704 DOI: 10.1007/s11033-022-08213-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 12/14/2022] [Indexed: 01/06/2023]
Abstract
BACKGROUND Soluble Amyloid-beta (Aβ) oligomers are thought to play a key role in the pathogenesis of Alzheimer's disease (AD), which is the most common age-associated neurodegenerative diseases with obvious neuropathological changes and functional decline in both cortical and subcortical regions. Melatonin is ubiquitously distributed and multifunctioning indoleamine. Accumulating studies support that melatonin is potential therapeutic molecule for AD through modulating a broad variety of signaling pathways. In recent years, Notch1 signaling pathway is been known involved in dynamic changes in the cellular architecture and function of adult brain, as well as associated with the pathophysiology of AD and other neurodegenerative disorders. METHODS AND RESULTS In this study, we performed real-time polymerase chain reaction, immunohistochemistry and western blotting analyses using the cerebral cortical tissues of Aβ1-42 oligomers-induced AD rats with or without melatonin treatment. Our results showed that soluble Aβ1-42 oligomers decreased the expression of the main components of Notch1 signaling pathway, Notch1, NICD and Hes1 in the cerebral cortex, and melatonin could restore the level of Notch1, NICD and Hes1. CONCLUSION This observation suggests that targeting of Notch1 signaling might be a promising therapeutic approach for AD and other age-associated neurodegenerative diseases, and melatonin might serve as a potential therapeutic agent for AD and other age-associated neurodegenerative diseases.
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9
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Willumsen N, Poole T, Nicholas JM, Fox NC, Ryan NS, Lashley T. Variability in the type and layer distribution of cortical Aβ pathology in familial Alzheimer's disease. Brain Pathol 2021; 32:e13009. [PMID: 34319632 PMCID: PMC9048809 DOI: 10.1111/bpa.13009] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 11/30/2022] Open
Abstract
Familial Alzheimer's disease (FAD) is caused by autosomal dominant mutations in the PSEN1, PSEN2 or APP genes, giving rise to considerable clinical and pathological heterogeneity in FAD. Here we investigate variability in clinical data and the type and distribution of Aβ pathologies throughout the cortical layers of different FAD mutation cases. Brain tissue from 20 FAD cases [PSEN1 pre-codon 200 (n = 10), PSEN1 post-codon 200 (n = 6), APP (n = 4)] were investigated. Frontal cortex sections were stained immunohistochemically for Aβ, and Nissl to define the cortical layers. The frequency of different amyloid-beta plaque types was graded for each cortical layer and the severity of cerebral amyloid angiopathy (CAA) was determined in cortical and leptomeningeal blood vessels. Comparisons were made between FAD mutations and APOE4 status, with associations between pathology, clinical and genetic data investigated. In this cohort, possession of an APOE4 allele was associated with increased disease duration but not with age at onset, after adjusting for mutation sub-group and sex. We found Aβ pathology to be heterogeneous between cases although Aβ load was highest in cortical layer 3 for all mutation groups and a higher Aβ load was associated with APOE4. The PSEN1 post-codon 200 group had a higher Aβ load in lower cortical layers, with a small number of this group having increased cotton wool plaque pathology in lower layers. Cotton wool plaque frequency was positively associated with the severity of CAA in the whole cohort and in the PSEN1 post-codon 200 group. Carriers of the same PSEN1 mutation can have differing patterns of Aβ deposition, potentially because of differences in risk factors. Our results highlight possible influences of APOE4 genotype, and PSEN1 mutation type on Aβ deposition, which may have effects on the clinical heterogeneity of FAD.
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Affiliation(s)
- Nanet Willumsen
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Teresa Poole
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK.,Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Jennifer M Nicholas
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK.,Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Nick C Fox
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK.,UK Dementia Research Institute at University College London, London, UK
| | - Natalie S Ryan
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK.,UK Dementia Research Institute at University College London, London, UK
| | - Tammaryn Lashley
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
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10
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Diana Neely M, Xie S, Prince LM, Kim H, Tukker AM, Aschner M, Thimmapuram J, Bowman AB. Single cell RNA sequencing detects persistent cell type- and methylmercury exposure paradigm-specific effects in a human cortical neurodevelopmental model. Food Chem Toxicol 2021; 154:112288. [PMID: 34089799 DOI: 10.1016/j.fct.2021.112288] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/14/2021] [Accepted: 05/15/2021] [Indexed: 12/13/2022]
Abstract
The developing human brain is uniquely vulnerable to methylmercury (MeHg) resulting in lasting effects especially in developing cortical structures. Here we assess by single-cell RNA sequencing (scRNAseq) persistent effects of developmental MeHg exposure in a differentiating cortical human-induced pluripotent stem cell (hiPSC) model which we exposed to in vivo relevant and non-cytotoxic MeHg (0.1 and 1.0 μM) concentrations. The cultures were exposed continuously for 6 days either once only during days 4-10, a stage representative of neural epithelial- and radial glia cells, or twice on days 4-10 and days 14-20, a somewhat later stage which includes intermediate precursors and early postmitotic neurons. After the completion of MeHg exposure the cultures were differentiated further until day 38 and then assessed for persistent MeHg-induced effects by scRNAseq. We report subtle, but significant changes in the population size of different cortical cell types/stages and cell cycle. We also observe MeHg-dependent differential gene expression and altered biological processes as determined by Gene Ontology analysis. Our data demonstrate that MeHg results in changes in gene expression in human developing cortical neurons that manifest well after cessation of exposure and that these changes are cell type-, developmental stage-, and exposure paradigm-specific.
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Affiliation(s)
- M Diana Neely
- Dept of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Shaojun Xie
- Bioinformatics Core, Purdue University, West Lafayette, IN, USA
| | - Lisa M Prince
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Hyunjin Kim
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Anke M Tukker
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Michael Aschner
- Dept of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | | | - Aaron B Bowman
- Dept of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA; School of Health Sciences, Purdue University, West Lafayette, IN, USA.
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11
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Identifying a Population of Glial Progenitors That Have Been Mistaken for Neurons in Embryonic Mouse Cortical Culture. eNeuro 2021; 8:ENEURO.0388-20.2020. [PMID: 33483322 PMCID: PMC7986526 DOI: 10.1523/eneuro.0388-20.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/16/2020] [Accepted: 12/28/2020] [Indexed: 12/17/2022] Open
Abstract
Experiments in primary culture have helped advance our understanding of the curious phenomenon of cell cycle-related neuronal death. In a differentiated postmitotic cell such as a neuron, aberrant cell cycle reentry is strongly associated with apoptosis. Indeed, in many pathologic conditions, neuronal populations at risk for death are marked by cells engaged in a cell cycle like process. The evidence for this conclusion is typically based on finding MAP2+ cells that are also positive for cell cycle-related proteins (e.g., cyclin D) or have incorporated thymidine analogs such as bromodeoxyuridine (BrdU) or 5-ethynyl-2’-deoxyuridine (EdU) into their nuclei. We now report that we and others may have partly been led astray in pursuing this line of work. Morphometric analysis of mouse embryonic cortical cultures reveals that the size of the “cycling” MAP2+ cells is significantly smaller than those of normal neurons, and their expression of MAP2 is significantly lower. This led us to ask whether, rather than representing fully developed neurons, they more closely resembled precursor-like cells. In support of this idea, we find that these small MAP2+ cells are immunopositive for nestin, a neuronal precursor marker, Olig2, an oligodendrocyte lineage marker, and neural/glial antigen 2 (NG2), an oligodendrocyte precursor marker. Tracking their behavior in culture, we find that they predominantly give rise to GFAP+ astrocytes instead of neurons or oligodendrocytes. These findings argue for a critical reexamination of previous reports of stimuli that lead to neuronal cell cycle-related death in primary cultures.
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12
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Esmail S, Danter WR. NEUBOrg: Artificially Induced Pluripotent Stem Cell-Derived Brain Organoid to Model and Study Genetics of Alzheimer's Disease Progression. Front Aging Neurosci 2021; 13:643889. [PMID: 33708104 PMCID: PMC7940675 DOI: 10.3389/fnagi.2021.643889] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 01/28/2021] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is the most common type of neurodegenerative diseases. There are over 44 million people living with the disease worldwide. While there are currently no effective treatments for AD, induced pluripotent stem cell-derived brain organoids have the potential to provide a better understanding of Alzheimer's pathogenesis. Nevertheless, developing brain organoid models is expensive, time consuming and often does not reflect disease progression. Using accurate and inexpensive computer simulations of human brain organoids can overcome the current limitations. Induced whole brain organoids (aiWBO) will greatly expand our ability to model AD and can guide wet lab research. In this study, we have successfully developed and validated artificially induced a whole brain organoid platform (NEUBOrg) using our previously validated machine learning platform, DeepNEU (v6.1). Using NEUBorg platform, we have generated aiWBO simulations of AD and provided a novel approach to test genetic risk factors associated with AD progression and pathogenesis.
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13
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Leszek J, Mikhaylenko EV, Belousov DM, Koutsouraki E, Szczechowiak K, Kobusiak-Prokopowicz M, Mysiak A, Diniz BS, Somasundaram SG, Kirkland CE, Aliev G. The Links between Cardiovascular Diseases and Alzheimer's Disease. Curr Neuropharmacol 2021; 19:152-169. [PMID: 32727331 PMCID: PMC8033981 DOI: 10.2174/1570159x18666200729093724] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/02/2020] [Accepted: 07/16/2020] [Indexed: 12/17/2022] Open
Abstract
The root cause of non-inherited Alzheimer's disease (AD) remains unknown despite hundreds of research studies performed to attempt to solve this problem. Since proper prophylaxis remains the best strategy, many scientists have studied the risk factors that may affect AD development. There is robust evidence supporting the hypothesis that cardiovascular diseases (CVD) may contribute to AD progression, as the diseases often coexist. Therefore, a lack of well-defined diagnostic criteria makes studying the relationship between AD and CVD complicated. Additionally, inflammation accompanies the pathogenesis of AD and CVD, and is not only a consequence but also implicated as a significant contributor to the course of the diseases. Of note, АроЕε4 is found to be one of the major risk factors affecting both the cardiovascular and nervous systems. According to genome wide association and epidemiological studies, numerous common risk factors have been associated with the development of AD-related pathology. Furthermore, the risk of developing AD and CVDs appears to be increased by a wide range of conditions and lifestyle factors: hypertension, dyslipidemia, hypercholesterolemia, hyperhomocysteinemia, gut/oral microbiota, physical activity, and diet. This review summarizes the literature and provides possible mechanistic links between CVDs and AD.
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Affiliation(s)
- Jerzy Leszek
- Address correspondence to these authors at the Department of Psychiatry, Wrocław Medical University, Ul. Pasteura 10, 50-367, Wroclaw, Poland;, E-mail: and GALLY International Research Institute, 7733 Louis Pasteur Drive, #330, San Antonio, TX 78229, USA; Tel: +1-210-442-8625 or +1-440-263-7461; E-mails: ,
| | | | | | | | | | | | | | | | | | | | - Gjumrakch Aliev
- Address correspondence to these authors at the Department of Psychiatry, Wrocław Medical University, Ul. Pasteura 10, 50-367, Wroclaw, Poland;, E-mail: and GALLY International Research Institute, 7733 Louis Pasteur Drive, #330, San Antonio, TX 78229, USA; Tel: +1-210-442-8625 or +1-440-263-7461; E-mails: ,
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14
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Shi X, Chai X, Yang Y, Cheng Q, Jiao Y, Chen H, Huang J, Yang C, Liu J. A tissue-specific collaborative mixed model for jointly analyzing multiple tissues in transcriptome-wide association studies. Nucleic Acids Res 2020; 48:e109. [PMID: 32978944 PMCID: PMC7641735 DOI: 10.1093/nar/gkaa767] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 08/14/2020] [Accepted: 09/03/2020] [Indexed: 12/13/2022] Open
Abstract
Transcriptome-wide association studies (TWASs) integrate expression quantitative trait loci (eQTLs) studies with genome-wide association studies (GWASs) to prioritize candidate target genes for complex traits. Several statistical methods have been recently proposed to improve the performance of TWASs in gene prioritization by integrating the expression regulatory information imputed from multiple tissues, and made significant achievements in improving the ability to detect gene-trait associations. Unfortunately, most existing multi-tissue methods focus on prioritization of candidate genes, and cannot directly infer the specific functional effects of candidate genes across different tissues. Here, we propose a tissue-specific collaborative mixed model (TisCoMM) for TWASs, leveraging the co-regulation of genetic variations across different tissues explicitly via a unified probabilistic model. TisCoMM not only performs hypothesis testing to prioritize gene-trait associations, but also detects the tissue-specific role of candidate target genes in complex traits. To make full use of widely available GWASs summary statistics, we extend TisCoMM to use summary-level data, namely, TisCoMM-S2. Using extensive simulation studies, we show that type I error is controlled at the nominal level, the statistical power of identifying associated genes is greatly improved, and the false-positive rate (FPR) for non-causal tissues is well controlled at decent levels. We further illustrate the benefits of our methods in applications to summary-level GWASs data of 33 complex traits. Notably, apart from better identifying potential trait-associated genes, we can elucidate the tissue-specific role of candidate target genes. The follow-up pathway analysis from tissue-specific genes for asthma shows that the immune system plays an essential function for asthma development in both thyroid and lung tissues.
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Affiliation(s)
- Xingjie Shi
- Department of Statistics, Nanjing University of Finance and Economics, Nanjing, China
- Centre for Quantitative Medicine, Health Services & Systems Research, Duke-NUS Medical School, Singapore
| | - Xiaoran Chai
- Beijing Advanced Innovation Center for Genomics (ICG) & Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, China
- School of Medicine, National University of Singapore, Singapore
| | - Yi Yang
- Centre for Quantitative Medicine, Health Services & Systems Research, Duke-NUS Medical School, Singapore
| | - Qing Cheng
- Centre for Quantitative Medicine, Health Services & Systems Research, Duke-NUS Medical School, Singapore
| | - Yuling Jiao
- School of Mathematics and Statistics, and Hubei Key Laboratory of Computational Science, Wuhan University, Wuhan, China
| | - Haoyue Chen
- School of International Studies, Zhejiang University, Hangzhou, China
| | - Jian Huang
- Department of Statistics and Actuarial Science, University of Iowa, USA
| | - Can Yang
- Department of Mathematics, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Jin Liu
- Centre for Quantitative Medicine, Health Services & Systems Research, Duke-NUS Medical School, Singapore
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15
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Alzheimer's Disease as a Result of Stimulus Reduction in a GABA-A-Deficient Brain: A Neurocomputational Model. Neural Plast 2020; 2020:8895369. [PMID: 33123190 PMCID: PMC7582082 DOI: 10.1155/2020/8895369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/17/2020] [Accepted: 09/09/2020] [Indexed: 02/07/2023] Open
Abstract
Several research studies point to the fact that sensory and cognitive reductions like cataracts, deafness, macular degeneration, or even lack of activity after job retirement, precede the onset of Alzheimer's disease. To simulate Alzheimer's disease earlier stages, which manifest in sensory cortices, we used a computational model of the koniocortex that is the first cortical stage processing sensory information. The architecture and physiology of the modeled koniocortex resemble those of its cerebral counterpart being capable of continuous learning. This model allows one to analyze the initial phases of Alzheimer's disease by “aging” the artificial koniocortex through synaptic pruning, by the modification of acetylcholine and GABA-A signaling, and by reducing sensory stimuli, among other processes. The computational model shows that during aging, a GABA-A deficit followed by a reduction in sensory stimuli leads to a dysregulation of neural excitability, which in the biological brain is associated with hypermetabolism, one of the earliest symptoms of Alzheimer's disease.
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16
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Neuroprotection against Amyloid- β-Induced DNA Double-Strand Breaks Is Mediated by Multiple Retinoic Acid-Dependent Pathways. Neural Plast 2020; 2020:9369815. [PMID: 32256561 PMCID: PMC7109576 DOI: 10.1155/2020/9369815] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/30/2020] [Accepted: 02/28/2020] [Indexed: 02/07/2023] Open
Abstract
In this study, we have investigated the role of all-trans-retinoic acid (RA) as a neuroprotective agent against Aβ1-42-induced DNA double-strand breaks (DSBs) in neuronal SH-SY5Y and astrocytic DI TNC1 cell lines and in murine brain tissues, by single-cell gel electrophoresis. We showed that RA does not only repair Aβ1-42-induced DSBs, as already known, but also prevents their occurrence. This effect is independent of that of other antioxidants studied, such as vitamin C, and appears to be mediated, at least in part, by changes in expression, not of the RARα, but of the PPARβ/δ and of antiamyloidogenic proteins, such as ADAM10, implying a decreased production of endogenous Aβ. Whereas Aβ1-42 needs transcription and translation for DSB production, RA protects against Aβ1-42-induced DSBs at the posttranslational level through both the RARα/β/γ and PPARβ/δ receptors as demonstrated by using specific antagonists. Furthermore, it could be shown by a proximity ligation assay that the PPARβ/δ-RXR interactions, not the RARα/β/γ-RXR interactions, increased in the cells when a 10 min RA treatment was followed by a 20 min Aβ1-42 treatment. Thus, the PPARβ/δ receptor, known for its antiapoptotic function, might for these short-time treatments play a role in neuroprotection via PPARβ/δ-RXR heterodimerization and possibly expression of antiamyloidogenic genes. Overall, this study shows that RA can not only repair Aβ1-42-induced DSBs but also prevent them via the RARα/β/γ and PPARβ/δ receptors. It suggests that the RA-dependent pathways belong to an anti-DSB Adaptative Gene Expression (DSB-AGE) system that can be targeted by prevention strategies to preserve memory in Alzheimer's disease and aging.
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17
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Grubman A, Chew G, Ouyang JF, Sun G, Choo XY, McLean C, Simmons RK, Buckberry S, Vargas-Landin DB, Poppe D, Pflueger J, Lister R, Rackham OJL, Petretto E, Polo JM. A single-cell atlas of entorhinal cortex from individuals with Alzheimer's disease reveals cell-type-specific gene expression regulation. Nat Neurosci 2019; 22:2087-2097. [PMID: 31768052 DOI: 10.1038/s41593-019-0539-4] [Citation(s) in RCA: 491] [Impact Index Per Article: 98.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There is currently little information available about how individual cell types contribute to Alzheimer's disease. Here we applied single-nucleus RNA sequencing to entorhinal cortex samples from control and Alzheimer's disease brains (n = 6 per group), yielding a total of 13,214 high-quality nuclei. We detail cell-type-specific gene expression patterns, unveiling how transcriptional changes in specific cell subpopulations are associated with Alzheimer's disease. We report that the Alzheimer's disease risk gene APOE is specifically repressed in Alzheimer's disease oligodendrocyte progenitor cells and astrocyte subpopulations and upregulated in an Alzheimer's disease-specific microglial subopulation. Integrating transcription factor regulatory modules with Alzheimer's disease risk loci revealed drivers of cell-type-specific state transitions towards Alzheimer's disease. For example, transcription factor EB, a master regulator of lysosomal function, regulates multiple disease genes in a specific Alzheimer's disease astrocyte subpopulation. These results provide insights into the coordinated control of Alzheimer's disease risk genes and their cell-type-specific contribution to disease susceptibility. These results are available at http://adsn.ddnetbio.com.
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Affiliation(s)
- Alexandra Grubman
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Clayton, Victoria, Australia
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
| | - Gabriel Chew
- Program in Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - John F Ouyang
- Program in Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Guizhi Sun
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Clayton, Victoria, Australia
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
| | - Xin Yi Choo
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Clayton, Victoria, Australia
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
- Department of Pathology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Catriona McLean
- Victorian Brain Bank, Florey Institute of Neurosciences, Parkville, Victoria, Australia
| | - Rebecca K Simmons
- ARC Center of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia, Australia
- The Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Sam Buckberry
- ARC Center of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia, Australia
- The Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Dulce B Vargas-Landin
- ARC Center of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia, Australia
- The Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Daniel Poppe
- ARC Center of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia, Australia
- The Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Jahnvi Pflueger
- ARC Center of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia, Australia
- The Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Ryan Lister
- ARC Center of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia, Australia
- The Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Owen J L Rackham
- Program in Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School, Singapore, Singapore.
| | - Enrico Petretto
- Program in Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School, Singapore, Singapore.
| | - Jose M Polo
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia.
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Clayton, Victoria, Australia.
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia.
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18
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Bott CJ, Johnson CG, Yap CC, Dwyer ND, Litwa KA, Winckler B. Nestin in immature embryonic neurons affects axon growth cone morphology and Semaphorin3a sensitivity. Mol Biol Cell 2019; 30:1214-1229. [PMID: 30840538 PMCID: PMC6724523 DOI: 10.1091/mbc.e18-06-0361] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 02/21/2019] [Accepted: 02/26/2019] [Indexed: 12/14/2022] Open
Abstract
Correct wiring in the neocortex requires that responses to an individual guidance cue vary among neurons in the same location, and within the same neuron over time. Nestin is an atypical intermediate filament expressed strongly in neural progenitors and is thus used widely as a progenitor marker. Here we show a subpopulation of embryonic cortical neurons that transiently express nestin in their axons. Nestin expression is thus not restricted to neural progenitors, but persists for 2-3 d at lower levels in newborn neurons. We found that nestin-expressing neurons have smaller growth cones, suggesting that nestin affects cytoskeletal dynamics. Nestin, unlike other intermediate filament subtypes, regulates cdk5 kinase by binding the cdk5 activator p35. Cdk5 activity is induced by the repulsive guidance cue Semaphorin3a (Sema3a), leading to axonal growth cone collapse in vitro. Therefore, we tested whether nestin-expressing neurons showed altered responses to Sema3a. We find that nestin-expressing newborn neurons are more sensitive to Sema3a in a roscovitine-sensitive manner, whereas nestin knockdown results in lowered sensitivity to Sema3a. We propose that nestin functions in immature neurons to modulate cdk5 downstream of the Sema3a response. Thus, the transient expression of nestin could allow temporal and/or spatial modulation of a neuron's response to Sema3a, particularly during early axon guidance.
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Affiliation(s)
- C. J. Bott
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - C. G. Johnson
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834
| | - C. C. Yap
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - N. D. Dwyer
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - K. A. Litwa
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834
| | - B. Winckler
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
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19
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Fairless R, Williams SK, Diem R. Calcium-Binding Proteins as Determinants of Central Nervous System Neuronal Vulnerability to Disease. Int J Mol Sci 2019; 20:ijms20092146. [PMID: 31052285 PMCID: PMC6539299 DOI: 10.3390/ijms20092146] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/26/2019] [Accepted: 04/27/2019] [Indexed: 12/14/2022] Open
Abstract
Neuronal subpopulations display differential vulnerabilities to disease, but the factors that determine their susceptibility are poorly understood. Toxic increases in intracellular calcium are a key factor in several neurodegenerative processes, with calcium-binding proteins providing an important first line of defense through their ability to buffer incoming calcium, allowing the neuron to quickly achieve homeostasis. Since neurons expressing different calcium-binding proteins have been reported to be differentially susceptible to degeneration, it can be hypothesized that rather than just serving as markers of different neuronal subpopulations, they might actually be a key determinant of survival. In this review, we will summarize some of the evidence that expression of the EF-hand calcium-binding proteins, calbindin, calretinin and parvalbumin, may influence the susceptibility of distinct neuronal subpopulations to disease processes.
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Affiliation(s)
- Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
| | - Sarah K Williams
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
| | - Ricarda Diem
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
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20
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Lyra E Silva NDM, Gonçalves RA, Boehnke SE, Forny-Germano L, Munoz DP, De Felice FG. Understanding the link between insulin resistance and Alzheimer's disease: Insights from animal models. Exp Neurol 2019; 316:1-11. [PMID: 30930096 DOI: 10.1016/j.expneurol.2019.03.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disease affecting millions of people worldwide. AD is characterized by a profound impairment of higher cognitive functions and still lacks any effective disease-modifying treatment. Defective insulin signaling has been implicated in AD pathophysiology, but the mechanisms underlying this process are not fully understood. Here, we review the molecular mechanisms underlying defective brain insulin signaling in rodent models of AD, and in a non-human primate (NHP) model of the disease that recapitulates features observed in AD brains. We further highlight similarities between the NHP and human brains and discuss why NHP models of AD are important to understand disease mechanisms and to improve the translation of effective therapies to humans. We discuss how studies using different animal models have contributed to elucidate the link between insulin resistance and AD.
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Affiliation(s)
| | | | - Susan E Boehnke
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Leticia Forny-Germano
- Institute of Medical Biochemistry Leopoldo De Meis, Federal University of Rio de Janeiro, Brazil
| | - Douglas P Munoz
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.
| | - Fernanda G De Felice
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada; Department of Psychiatry, Queen's University, Kingston, ON, Canada; Institute of Medical Biochemistry Leopoldo De Meis, Federal University of Rio de Janeiro, Brazil.
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21
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Afshar S, Shahidi S, Rohani AH, Soleimani Asl S, Komaki A. Protective effects of 5-HT1A receptor antagonist and 5-HT2A receptor agonist on the biochemical and histological features in a rat model of Alzheimer’s disease. J Chem Neuroanat 2019; 96:140-147. [DOI: 10.1016/j.jchemneu.2019.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 02/06/2023]
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22
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Afshar S, Shahidi S, Rohani AH, Komaki A, Asl SS. The effect of NAD-299 and TCB-2 on learning and memory, hippocampal BDNF levels and amyloid plaques in Streptozotocin-induced memory deficits in male rats. Psychopharmacology (Berl) 2018; 235:2809-2822. [PMID: 30027497 DOI: 10.1007/s00213-018-4973-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/11/2018] [Indexed: 01/08/2023]
Abstract
RATIONALE Alzheimer's disease (AD) is the most common form of dementia characterized by a progressive decline in cognitive function. The serotonergic system via the 5-HT1A receptor and 5-HT2A receptor is proposed to affect the cognitive process. OBJECTIVE In the present study, the effects of NAD-299 (5-HT1AR antagonist) and TCB-2 (5-HT2AR agonist) on learning and memory processes, hippocampal brain-derived neurotrophic factor (BDNF) levels, neuronal necrosis, and Aβ plaque production have been investigated on the intracerebroventricular (icv) injection of streptozotocin (STZ)-induced memory deficits in rats. METHODS Fifty-four adult male Wistar rats (250-300 g) were divided into six groups (n = 9 in each group): control, sham-operated, AD (icv-STZ (3 mg/kg, 10 μl)), AD+NAD-299 (5 μg/1 μl icv for 30 days), AD+TCB-2 (5 μg/1 μl icv for 30 days), and AD+NAD-299 + TCB-2 (NAD-299 (5 μg/0.5 μl icv) and TCB-2 (5 μg/0.5 μl icv) for 30 days). Following the treatment period, rats were subjected to behavioral tests of learning and memory. Then, hippocampal BDNF, amyloid-beta (Aβ) plaque, and neuronal loss were determined by ELISA Kit, Congo red staining, and Nissl staining, respectively. RESULTS The results of behavioral tests showed that icv-STZ injection decreased the discrimination index in the novel object recognition (NOR) test. In the passive avoidance learning (PAL) task, icv-STZ injection significantly decreased step-through latency (STLr) and increased time spent in dark compartment (TDC). Treatment with NAD-299, TCB-2, and NAD-299 + TCB-2 attenuated the STZ-induced memory impairment in both NOR and PAL tasks. icv-STZ induced a decrease in hippocampal BDNF levels and increased Aβ plaques production in the brain, whereas treatment with NAD-299, TCB-2, and NAD-299 + TCB-2 reduced Aβ plaques in the brain and increased the hippocampal BDNF level. Results of Nissl staining showed that icv-STZ injection increased neuronal loss in the hippocampus, while treatment with NAD-299, TCB-2, and NAD-299 + TCB-2 reduced hippocampal neurodegeneration. CONCLUSION These findings suggest that 5-HT1AR blockade by NAD-299 and 5-HT2AR activation by TCB-2 improve cognitive dysfunction in icv-STZ-treated rats, and these drugs may potentially prevent the progression of AD.
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Affiliation(s)
- Simin Afshar
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Siamak Shahidi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Ali Haeri Rohani
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Sara Soleimani Asl
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
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23
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Mayer C, Bruehl C, Salt EL, Diem R, Draguhn A, Fairless R. Selective Vulnerability of αOFF Retinal Ganglion Cells during Onset of Autoimmune Optic Neuritis. Neuroscience 2018; 393:258-272. [PMID: 30075244 DOI: 10.1016/j.neuroscience.2018.07.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/04/2018] [Accepted: 07/23/2018] [Indexed: 12/27/2022]
Abstract
Retinal ganglion cells (RGCs), a diverse body of neurons which relay visual signals from the retina to the higher processing regions of the brain, are susceptible to neurodegenerative processes in several diseases affecting the retina. Previous evidence shows that RGCs are damaged at early stages of autoimmune optic neuritis (AON), prior to subsequent degeneration of the optic nerve. In order to study cell type-specific vulnerability of RGCs we performed immunohistochemical and patch-clamp electrophysiological analyses of RGCs following induction of AON using the experimental autoimmune encephalomyelitis model in Brown Norway rats. We report that αRGCs are more susceptible to degeneration than the global RGC population as a whole, with functional and structural changes beginning even prior to demyelination and inflammatory infiltration of the optic nerve (where the RGC axons reside). Functional classification of αRGCs into OFF-sustained, OFF-transient and ON-sustained subtypes revealed that αOFF RGCs (both sustained and transient subtypes) are more vulnerable than αON RGCs, as indicated by reductions in light-evoked post-synaptic currents and retraction of dendritic arbours. Classification of neuronal susceptibility is a first step in furthering our understanding of what underlies a neuron's vulnerability to degenerative processes, necessary for the future development of effective neuroprotective strategies.
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Affiliation(s)
- Christina Mayer
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany
| | - Claus Bruehl
- Institute of Physiology and Pathophysiology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Emma L Salt
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany
| | - Ricarda Diem
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
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24
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Generation of a human induced pluripotent stem cell-based model for tauopathies combining three microtubule-associated protein TAU mutations which displays several phenotypes linked to neurodegeneration. Alzheimers Dement 2018; 14:1261-1280. [PMID: 30036493 DOI: 10.1016/j.jalz.2018.05.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 04/28/2018] [Accepted: 05/13/2018] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Tauopathies are neurodegenerative diseases characterized by TAU protein-related pathology, including frontotemporal dementia and Alzheimer's disease among others. Mutant TAU animal models are available, but none of them faithfully recapitulates human pathology and are not suitable for drug screening. METHODS To create a new in vitro tauopathy model, we generated a footprint-free triple MAPT-mutant human induced pluripotent stem cell line (N279K, P301L, and E10+16 mutations) using clustered regularly interspaced short palindromic repeats-FokI and piggyBac transposase technology. RESULTS Mutant neurons expressed pathogenic 4R and phosphorylated TAU, endogenously triggered TAU aggregation, and had increased electrophysiological activity. TAU-mutant cells presented deficiencies in neurite outgrowth, aberrant sequence of differentiation to cortical neurons, and a significant activation of stress response pathways. RNA sequencing confirmed stress activation, demonstrated a shift toward GABAergic identity, and an upregulation of neurodegenerative pathways. DISCUSSION In summary, we generated a novel in vitro human induced pluripotent stem cell TAU-mutant model displaying neurodegenerative disease phenotypes that could be used for disease modeling and drug screening.
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25
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Luo F, Zhang J, Burke K, Romito-DiGiacomo RR, Miller RH, Yang Y. Oligodendrocyte-specific loss of Cdk5 disrupts the architecture of nodes of Ranvier as well as learning and memory. Exp Neurol 2018; 306:92-104. [PMID: 29729246 DOI: 10.1016/j.expneurol.2018.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/10/2018] [Accepted: 05/01/2018] [Indexed: 12/31/2022]
Abstract
Myelination of the central nervous system is important for normal motor and sensory neuronal function and recent studies also link it to efficient learning and memory. Cyclin-dependent kinase 5 (Cdk5) is required for normal oligodendrocyte development, myelination and myelin repair. Here we show that conditional deletion of Cdk5 by targeting with CNP (CNP;Cdk5 CKO) results in hypomyelination and disruption of the structural integrity of Nodes of Ranvier. In addition, CNP;Cdk5 CKO mice exhibited a severe impairment of learning and memory compared to controls that may reflect perturbed neuron-glial interactions. Co-culture of cortical neurons with CNP;Cdk5 CKO oligodendrocyte lineage cells resulted in a significant reduction in the density of neuronal dendritic spines. In short term fear-conditioning studies, CNP;Cdk5 CKO mice had decreased hippocampal levels of immediate early genes such as Arc and Fos, and lower levels of p-CREB and p-cofilin suggested these pathways are affected by the levels of myelination. The novel roles of Cdk5 in oligodendrocyte lineage cells may provide insights for helping understand the cognitive changes sometimes seen in demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- Fucheng Luo
- Department of Neurology, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, United States
| | - Jessie Zhang
- Department of Neurology, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, United States
| | - Kathryn Burke
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, United States
| | - Rita R Romito-DiGiacomo
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, United States
| | - Robert H Miller
- Department of Anatomy and Regenerative Biology, George Washington University, Washington DC 20037, United States.
| | - Yan Yang
- Department of Neurology, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, United States; Center for Translational Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, United States.
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26
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Landin-Romero R, Kumfor F, Leyton CE, Irish M, Hodges JR, Piguet O. Disease-specific patterns of cortical and subcortical degeneration in a longitudinal study of Alzheimer's disease and behavioural-variant frontotemporal dementia. Neuroimage 2017; 151:72-80. [PMID: 27012504 DOI: 10.1016/j.neuroimage.2016.03.032] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/14/2016] [Accepted: 03/14/2016] [Indexed: 02/02/2023] Open
Affiliation(s)
- Ramon Landin-Romero
- Neuroscience Research Australia, Sydney, Australia; Australia Research Council Centre of Excellence in Cognition and its Disorders, Sydney, Australia; School of Medical Sciences, the University of New South Wales, Sydney, Australia.
| | - Fiona Kumfor
- Neuroscience Research Australia, Sydney, Australia; Australia Research Council Centre of Excellence in Cognition and its Disorders, Sydney, Australia; School of Medical Sciences, the University of New South Wales, Sydney, Australia
| | - Cristian E Leyton
- Neuroscience Research Australia, Sydney, Australia; Australia Research Council Centre of Excellence in Cognition and its Disorders, Sydney, Australia; Faculty of Health Sciences, the University of Sydney, Lidcombe, NSW, Australia
| | - Muireann Irish
- Neuroscience Research Australia, Sydney, Australia; Australia Research Council Centre of Excellence in Cognition and its Disorders, Sydney, Australia; School of Psychology, the University of New South Wales, Sydney, Australia
| | - John R Hodges
- Neuroscience Research Australia, Sydney, Australia; Australia Research Council Centre of Excellence in Cognition and its Disorders, Sydney, Australia; School of Medical Sciences, the University of New South Wales, Sydney, Australia
| | - Olivier Piguet
- Neuroscience Research Australia, Sydney, Australia; Australia Research Council Centre of Excellence in Cognition and its Disorders, Sydney, Australia; School of Medical Sciences, the University of New South Wales, Sydney, Australia
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Hohman TJ, Dumitrescu L, Cox NJ, Jefferson AL. Genetic resilience to amyloid related cognitive decline. Brain Imaging Behav 2017; 11:401-409. [PMID: 27743375 PMCID: PMC5392179 DOI: 10.1007/s11682-016-9615-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Preclinical Alzheimer's disease (AD) is characterized by amyloid deposition in the absence of overt clinical impairment. There is substantial heterogeneity in the long-term clinical outcomes among amyloid positive individuals, yet limited work has focused on identifying molecular factors driving resilience from amyloid-related cognitive impairment. We apply a recently developed predicted gene expression analysis (PrediXcan) to identify genes that modify the association between baseline amyloid deposition and longitudinal cognitive changes. Participants free of clinical AD (n = 631) were selected from the AD Neuroimaging Initiative (ADNI) who had a baseline positron emission tomography measure of amyloid deposition (quantified as a standard uptake value ratio), longitudinal neuropsychological data, and genetic data. PrediXcan was used to impute gene expression levels across 15 heart and brain tissues. Mixed effect regression models assessed the interaction between predicted gene expression levels and amyloid deposition on longitudinal cognitive outcomes. The predicted gene expression levels for two genes in the coronary artery (CNTLN, PROK1) and two genes in the atrial appendage (PRSS50, PROK1) interacted with amyloid deposition on episodic memory performance. The predicted gene expression levels for two additional genes (TMC4 in the basal ganglia and HMBS in the aorta) interacted with amyloid deposition on executive function performance. Post-hoc analyses provide additional validation of the HMBS and PROK1 effects across two independent subsets of ADNI using two additional metrics of amyloid deposition. These results highlight a subset of unique candidate genes of resilience and provide evidence that cell-cycle regulation, angiogenesis, and heme biosynthesis likely play a role in AD progression.
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Affiliation(s)
- Timothy J Hohman
- Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, 1207 17th Ave S, Suite 204F, Nashville, TN, 37212, USA.
| | - Logan Dumitrescu
- Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, 1207 17th Ave S, Suite 204F, Nashville, TN, 37212, USA
| | - Nancy J Cox
- Vanderbilt Genetics Institute, Division of Genetic Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Angela L Jefferson
- Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, 1207 17th Ave S, Suite 204F, Nashville, TN, 37212, USA
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28
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Nakajima K, So M, Takahashi K, Tagawa YI, Hirao M, Goto Y, Ogi H. Optimized Ultrasonic Irradiation Finds Out Ultrastable Aβ1–40 Oligomers. J Phys Chem B 2017; 121:2603-2613. [DOI: 10.1021/acs.jpcb.7b01409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kichitaro Nakajima
- Graduate
School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Masatomo So
- Institute
for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kazuma Takahashi
- School
of Life Science and Technology, Tokyo Institute of Technology, 4259 B51, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan
| | - Yoh-ichi Tagawa
- School
of Life Science and Technology, Tokyo Institute of Technology, 4259 B51, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan
| | - Masahiko Hirao
- Graduate
School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Yuji Goto
- Institute
for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hirotsugu Ogi
- Graduate
School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
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29
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Faghihi F, Moustafa AA. Impaired neurogenesis of the dentate gyrus is associated with pattern separation deficits: A computational study. J Integr Neurosci 2016; 15:277-293. [PMID: 27650784 DOI: 10.1142/s0219635216500175] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The separation of input patterns received from the entorhinal cortex (EC) by the dentate gyrus (DG) is a well-known critical step of information processing in the hippocampus. Although the role of interneurons in separation pattern efficiency of the DG has been theoretically known, the balance of neurogenesis of excitatory neurons and interneurons as well as its potential role in information processing in the DG is not fully understood. In this work, we study separation efficiency of the DG for different rates of neurogenesis of interneurons and excitatory neurons using a novel computational model in which we assume an increase in the synaptic efficacy between excitatory neurons and interneurons and then its decay over time. Information processing in the EC and DG was simulated as information flow in a two layer feed-forward neural network. The neurogenesis rate was modeled as the percentage of new born neurons added to the neuronal population in each time bin. The results show an important role of an optimal neurogenesis rate of interneurons and excitatory neurons in the DG in efficient separation of inputs from the EC in pattern separation tasks. The model predicts that any deviation of the optimal values of neurogenesis rates leads to different decreased levels of the separation deficits of the DG which influences its function to encode memory.
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Affiliation(s)
- Faramarz Faghihi
- * Department of Cognitive Modeling, Institute for Cognitive Science, Pardis, 303-735-3602, Iran.,† Department of Cognitive Modeling, Institute for Brain and Cognitive Science, Shahid Beheshti University, Tehran, 1983969411, Iran
| | - Ahmed A Moustafa
- ‡ School of Social Sciences and Psychology & Marcs Institute for Brain and Behaviour, University of Western Sydney, Milperra, New South Wales, 2214, Australia
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30
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Chen J, Chen Y, Vail G, Chow H, Zhang Y, Louie L, Li J, Hart RP, Plummer MR, Herrup K. The impact of glutamine supplementation on the symptoms of ataxia-telangiectasia: a preclinical assessment. Mol Neurodegener 2016; 11:60. [PMID: 27538496 PMCID: PMC4991002 DOI: 10.1186/s13024-016-0127-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 08/06/2016] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Our previous studies of Alzheimer's disease (AD) suggested that glutamine broadly improves cellular readiness to respond to stress and acts as a neuroprotectant both in vitro and in AD mouse models. We now expand our studies to a second neurodegenerative disease, ataxia-telangiectasia (A-T). Unlike AD, where clinically significant cognitive decline does not typically occur before age 65, A-T symptoms appear in early childhood and are caused exclusively by mutations in the ATM (A-T mutated) gene. RESULTS Genetically ATM-deficient mice and wild type littermates were maintained with or without 4 % glutamine in their drinking water for several weeks. In ATM mutants, glutamine supplementation restored serum glutamine and glucose levels and reduced body weight loss. Lost neurophysiological function assessed through the magnitude of hippocampal long term potentiation was significantly restored. Glutamine supplemented mice also showed reduced thymus pathology and, remarkably, a full one-third extension of lifespan. In vitro assays revealed that ATM-deficient cells are more sensitive to glutamine deprivation, while supra-molar glutamine (8 mM) partially rescued the reduction of BDNF expression and HDAC4 nuclear translocation of genetically mutant Atm(-/-) neurons. Analysis of microarray data suggested that glutamine metabolism is significantly altered in human A-T brains as well. CONCLUSION Glutamine is a powerful part of an organism's internal environment. Changes in its concentrations can have a huge impact on the function of all organ systems, especially the brain. Glutamine supplementation thus bears consideration as a therapeutic strategy for the treatment of human A-T and perhaps other neurodegenerative diseases.
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Affiliation(s)
- Jianmin Chen
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA.
| | - Yanping Chen
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA
| | - Graham Vail
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA
| | - Heiman Chow
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Yang Zhang
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Lauren Louie
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA
| | - Jiali Li
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA.,Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Ronald P Hart
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA
| | - Mark R Plummer
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA
| | - Karl Herrup
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA.,Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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31
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Leyton CE, Britton AK, Hodges JR, Halliday GM, Kril JJ. Distinctive pathological mechanisms involved in primary progressive aphasias. Neurobiol Aging 2016; 38:82-92. [DOI: 10.1016/j.neurobiolaging.2015.10.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/16/2015] [Accepted: 10/17/2015] [Indexed: 12/12/2022]
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32
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Handel AE, Chintawar S, Lalic T, Whiteley E, Vowles J, Giustacchini A, Argoud K, Sopp P, Nakanishi M, Bowden R, Cowley S, Newey S, Akerman C, Ponting CP, Cader MZ. Assessing similarity to primary tissue and cortical layer identity in induced pluripotent stem cell-derived cortical neurons through single-cell transcriptomics. Hum Mol Genet 2016; 25:989-1000. [PMID: 26740550 PMCID: PMC4754051 DOI: 10.1093/hmg/ddv637] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/31/2015] [Indexed: 12/12/2022] Open
Abstract
Induced pluripotent stem cell (iPSC)-derived cortical neurons potentially present a powerful new model to understand corticogenesis and neurological disease. Previous work has established that differentiation protocols can produce cortical neurons, but little has been done to characterize these at cellular resolution. In particular, it is unclear to what extent in vitro two-dimensional, relatively disordered culture conditions recapitulate the development of in vivo cortical layer identity. Single-cell multiplex reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) was used to interrogate the expression of genes previously implicated in cortical layer or phenotypic identity in individual cells. Totally, 93.6% of single cells derived from iPSCs expressed genes indicative of neuronal identity. High proportions of single neurons derived from iPSCs expressed glutamatergic receptors and synaptic genes. And, 68.4% of iPSC-derived neurons expressing at least one layer marker could be assigned to a laminar identity using canonical cortical layer marker genes. We compared single-cell RNA-seq of our iPSC-derived neurons to available single-cell RNA-seq data from human fetal and adult brain and found that iPSC-derived cortical neurons closely resembled primary fetal brain cells. Unexpectedly, a subpopulation of iPSC-derived neurons co-expressed canonical fetal deep and upper cortical layer markers. However, this appeared to be concordant with data from primary cells. Our results therefore provide reassurance that iPSC-derived cortical neurons are highly similar to primary cortical neurons at the level of single cells but suggest that current layer markers, although effective, may not be able to disambiguate cortical layer identity in all cells.
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Affiliation(s)
- Adam E Handel
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, Oxfordshire OX1 3QX, UK, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, Oxfordshire OX3 9DS, UK
| | - Satyan Chintawar
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, Oxfordshire OX3 9DS, UK
| | - Tatjana Lalic
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, Oxfordshire OX3 9DS, UK
| | - Emma Whiteley
- Department of Pharmacology, University of Oxford, Oxford, Oxfordshire OX1 3QT, UK
| | - Jane Vowles
- Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire OX1 3RE, UK
| | - Alice Giustacchini
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, Oxfordshire OX3 9DS, UK
| | - Karene Argoud
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, Oxfordshire OX3 7BN and
| | - Paul Sopp
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, Oxfordshire OX3 9DS, UK
| | - Mahito Nakanishi
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
| | - Rory Bowden
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, Oxfordshire OX3 7BN and
| | - Sally Cowley
- Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire OX1 3RE, UK
| | - Sarah Newey
- Department of Pharmacology, University of Oxford, Oxford, Oxfordshire OX1 3QT, UK
| | - Colin Akerman
- Department of Pharmacology, University of Oxford, Oxford, Oxfordshire OX1 3QT, UK
| | - Chris P Ponting
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, Oxfordshire OX1 3QX, UK
| | - M Zameel Cader
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, Oxfordshire OX3 9DS, UK,
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Ctip2-, Satb2-, Prox1-, and GAD65-Expressing Neurons in Rat Cultures: Preponderance of Single- and Double-Positive Cells, and Cell Type-Specific Expression of Neuron-Specific Gene Family Members, Nsg-1 (NEEP21) and Nsg-2 (P19). PLoS One 2015; 10:e0140010. [PMID: 26465886 PMCID: PMC4605768 DOI: 10.1371/journal.pone.0140010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 08/31/2015] [Indexed: 11/19/2022] Open
Abstract
The brain consists of many distinct neuronal cell types, but which cell types are present in widely used primary cultures of embryonic rodent brain is often not known. We characterized how abundantly four cell type markers (Ctip2, Satb2, Prox1, GAD65) were represented in cultured rat neurons, how easily neurons expressing different markers can be transfected with commonly used plasmids, and whether neuronal-enriched endosomal proteins Nsg-1 (NEEP21) and Nsg-2 (P19) are ubiquitously expressed in all types of cultured neurons. We found that cultured neurons stably maintain cell type identities that are reflective of cell types in vivo. This includes neurons maintaining simultaneous expression of two transcription factors, such as Ctip2+/Satb2+ or Prox1+/Ctip2+ double-positive cells, which have also been described in vivo. Secondly, we established the superior efficiency of CAG promoters for both Lipofectamine-mediated transfection as well as for electroporation. Thirdly, we discovered that Nsg-1 and Nsg-2 were not expressed equally in all neurons: whereas high levels of both Nsg-1 and Nsg-2 were found in Satb2-, Ctip2-, and GAD65-positive neurons, Prox1-positive neurons in hippocampal cultures expressed low levels of both. Our findings thus highlight the importance of identifying neuronal cell types for doing cell biology in cultured neurons: Keeping track of neuronal cell type might uncover effects in assays that might otherwise be masked by the mixture of responsive and non-responsive neurons in the dish.
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Mathur R, Ince PG, Minett T, Garwood CJ, Shaw PJ, Matthews FE, Brayne C, Simpson JE, Wharton SB. A reduced astrocyte response to β-amyloid plaques in the ageing brain associates with cognitive impairment. PLoS One 2015; 10:e0118463. [PMID: 25707004 PMCID: PMC4338046 DOI: 10.1371/journal.pone.0118463] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/18/2014] [Indexed: 12/18/2022] Open
Abstract
Aims β-amyloid (Aβ) plaques are a key feature of Alzheimer’s disease pathology but correlate poorly with dementia. They are associated with astrocytes which may modulate the effect of Aβ-deposition on the neuropil. This study characterised the astrocyte response to Aβ plaque subtypes, and investigated their association with cognitive impairment. Methods Aβ plaque subtypes were identified in the cingulate gyrus using dual labelling immunohistochemistry to Aβ and GFAP+ astrocytes, and quantitated in two cortical areas: the area of densest plaque burden and the deep cortex near the white matter border (layer VI). Three subtypes were defined for both diffuse and compact plaques (also known as classical or core-plaques): Aβ plaque with (1) no associated astrocytes, (2) focal astrogliosis or (3) circumferential astrogliosis. Results In the area of densest burden, diffuse plaques with no astrogliosis (β = -0.05, p = 0.001) and with focal astrogliosis (β = -0.27, p = 0.009) significantly associated with lower MMSE scores when controlling for sex and age at death. In the deep cortex (layer VI), both diffuse and compact plaques without astrogliosis associated with lower MMSE scores (β = -0.15, p = 0.017 and β = -0.81, p = 0.03, respectively). Diffuse plaques with no astrogliosis in layer VI related to dementia status (OR = 1.05, p = 0.025). In the area of densest burden, diffuse plaques with no astrogliosis or with focal astrogliosis associated with increasing Braak stage (β = 0.01, p<0.001 and β = 0.07, p<0.001, respectively), and ApoEε4 genotype (OR = 1.02, p = 0.001 and OR = 1.10, p = 0.016, respectively). In layer VI all plaque subtypes associated with Braak stage, and compact amyloid plaques with little and no associated astrogliosis associated with ApoEε4 genotype (OR = 1.50, p = 0.014 and OR = 0.10, p = 0.003, respectively). Conclusions Reactive astrocytes in close proximity to either diffuse or compact plaques may have a neuroprotective role in the ageing brain, and possession of at least one copy of the ApoEε4 allele impacts the astroglial response to Aβ plaques.
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Affiliation(s)
- Ryan Mathur
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
| | - Paul G. Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
| | - Thais Minett
- Institute of Public Health, University of Cambridge, Cambridge, England, United Kingdom
| | - Claire J. Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
| | - Pamela J. Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
| | | | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, England, United Kingdom
| | - Julie E. Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
- * E-mail:
| | - Stephen B. Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
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Fakhran S, Yaeger K, Alhilali L. Symptomatic White Matter Changes in Mild Traumatic Brain Injury Resemble Pathologic Features of Early Alzheimer Dementia. Radiology 2013; 269:249-57. [DOI: 10.1148/radiol.13122343] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Comparison of frailty of primary neurons, embryonic, and aging mouse cortical layers. Neurobiol Aging 2013; 35:322-30. [PMID: 24011540 DOI: 10.1016/j.neurobiolaging.2013.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 05/02/2013] [Accepted: 08/05/2013] [Indexed: 11/23/2022]
Abstract
Superficial layers I to III of the human cerebral cortex are more vulnerable toward Aβ peptides than deep layers V to VI in aging. Three models of layers were used to investigate this pattern of frailty. First, primary neurons from E14 and E17 embryonic murine cortices, corresponding respectively to future deep and superficial layers, were treated either with Aβ(1-42), okadaic acid, or kainic acid. Second, whole E14 and E17 embryonic cortices, and third, in vitro separated deep and superficial layers of young and old C57BL/6J mice, were treated identically. We observed that E14 and E17 neurons in culture were prone to death after the Aβ and particularly the kainic acid treatment. This was also the case for the superficial layers of the aged cortex, but not for the embryonic, the young cortex, and the deep layers of the aged cortex. Thus, the aged superficial layers appeared to be preferentially vulnerable against Aβ and kainic acid. This pattern of vulnerability corresponds to enhanced accumulation of senile plaques in the superficial cortical layers with aging and Alzheimer's disease.
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Herrup K. ATM and the epigenetics of the neuronal genome. Mech Ageing Dev 2013; 134:434-9. [PMID: 23707635 DOI: 10.1016/j.mad.2013.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 05/01/2013] [Accepted: 05/17/2013] [Indexed: 01/28/2023]
Abstract
Ataxia-telangiectasia (A-T) is a neurodegenerative syndrome caused by the mutation of the ATM gene. The ATM protein is a PI3kinase family member best known for its role in the DNA damage response. While repair of DNA damage is a critical function that every CNS neuron must perform, a growing body of evidence indicates that the full range of ATM functions includes some that are unrelated to DNA damage yet are essential to neuronal survival and normal function. For example, ATM participates in the regulation of synaptic vesicle trafficking and is essential for the maintenance of normal LTP. In addition ATM helps to ensure the cytoplasmic localization of HDAC4 and thus maintains the histone 'code' of the neuronal genome by suppressing genome-wide histone deacetylation, which alters the message and protein levels of many genes that are important for neuronal survival and function. The growing list of ATM functions that go beyond its role in the DNA damage response offers a new perspective on why individuals with A-T express such a wide range of neurological symptoms, and suggests that not all A-T symptoms need to be understood in the context of the DNA repair process.
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Affiliation(s)
- Karl Herrup
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, United States; Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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Pro- and anti-mitogenic actions of pituitary adenylate cyclase-activating polypeptide in developing cerebral cortex: potential mediation by developmental switch of PAC1 receptor mRNA isoforms. J Neurosci 2013; 33:3865-78. [PMID: 23447598 DOI: 10.1523/jneurosci.1062-12.2013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
During corticogenesis, pituitary adenylate cyclase-activating polypeptide (PACAP; ADCYAP1) may contribute to proliferation control by activating PAC1 receptors of neural precursors in the embryonic ventricular zone. PAC1 receptors, specifically the hop and short isoforms, couple differentially to and activate distinct pathways that produce pro- or anti-mitogenic actions. Previously, we found that PACAP was an anti-mitogenic signal from embryonic day 13.5 (E13.5) onward both in culture and in vivo and activated cAMP signaling through the short isoform. However, we now find that mice deficient in PACAP exhibited a decrease in the BrdU labeling index (LI) in E9.5 cortex, suggesting that PACAP normally promotes proliferation at this stage. To further define mechanisms, we established a novel culture model in which the viability of very early cortical precursors (E9.5 mouse and E10.5 rat) could be maintained. At this stage, we found that PACAP evoked intracellular calcium fluxes and increased phospho-PKC levels, as well as stimulated G1 cyclin mRNAs and proteins, S-phase entry, and proliferation without affecting cell survival. Significantly, expression of hop receptor isoform was 24-fold greater than the short isoform at E10.5, a ratio that was reversed at E14.5 when short expression was 15-fold greater and PACAP inhibited mitogenesis. Enhanced hop isoform expression, elicited by in vitro treatment of E10.5 precursors with retinoic acid, correlated with sustained pro-mitogenic action of PACAP beyond the developmental switch. Conversely, depletion of hop receptor using short-hairpin RNA abolished PACAP mitogenic stimulation at E10.5. These observations suggest that PACAP elicits temporally specific effects on cortical proliferation via developmentally regulated expression of specific receptor isoforms.
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Millet LJ, Collens MB, Perry GLW, Bashir R. Pattern analysis and spatial distribution of neurons in culture. Integr Biol (Camb) 2011; 3:1167-78. [PMID: 22057472 DOI: 10.1039/c1ib00054c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The nervous system is a complex, highly-ordered, integrated network of cells. Dispersed cultures of neurons enable investigations into intrinsic cellular functions without the complexities inherent in the intact nervous system. This culture process generates a homogeneously dispersed population that is assumed to be spatially random. Despite the vast number of studies utilizing dispersed neurons, few studies address the spatial distribution of large populations of neurons, in vitro. We used ink-jet printing and surface chemistry to define patterned areas of poly-lysine adhesion (∼50 μm spots) juxtaposed against a fluorinated-silane background. We quantitatively analysed populations of patterned neurons on printed protein spots, and unpatterned neurons. Using a microarray scanner, we acquired large images (72 mm × 22 mm) of patterns, and neurons with and without patterns. Fast Fourier transformation (FFT) image analysis was used to determine global alignment of neurons to patterns. Through point pattern analysis, we described the spatial organization of dispersed neurons with, or without, patterned substrates. Patterned neurons show spatial organization characteristics reminiscent of printed patterns, with spatial distributions representative of unpatterned neurons. Most notably, both patterned and unpatterned neurons show departure from null models of complete spatial randomness (CSR; a homogeneous Poisson process) at shorter distances with conformity to CSR occurring at longer distances. Cellular morphometrics show that when compared to their unpatterned counterparts, spot-patterned neurons exhibit a significant increase (p < 0.0001) in the mean dendritic circularity and an increase in the number of more circular neurons. Through neurite tracing, we show that dendritic processes are also highly confined to patterned areas, and that they are on average 58% shorter than dendrites of neurons without patterns. Our findings show that patterned areas change the spatial organization of the somata and dendrites of cultured neurons, and that traditional neuronal cultures deviate from CSR.
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Affiliation(s)
- Larry J Millet
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Krajewska M, You Z, Rong J, Kress C, Huang X, Yang J, Kyoda T, Leyva R, Banares S, Hu Y, Sze CH, Whalen MJ, Salmena L, Hakem R, Head BP, Reed JC, Krajewski S. Neuronal deletion of caspase 8 protects against brain injury in mouse models of controlled cortical impact and kainic acid-induced excitotoxicity. PLoS One 2011; 6:e24341. [PMID: 21957448 PMCID: PMC3174961 DOI: 10.1371/journal.pone.0024341] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 08/09/2011] [Indexed: 11/25/2022] Open
Abstract
Background Acute brain injury is an important health problem. Given the critical position of caspase 8 at the crossroads of cell death pathways, we generated a new viable mouse line (Ncasp8−/−), in which the gene encoding caspase 8 was selectively deleted in neurons by cre-lox system. Methodology/Principal Findings Caspase 8 deletion reduced rates of neuronal cell death in primary neuronal cultures and in whole brain organotypic coronal slice cultures prepared from 4 and 8 month old mice and cultivated up to 14 days in vitro. Treatments of cultures with recombinant murine TNFα (100 ng/ml) or TRAIL (250 ng/mL) plus cyclohexamide significantly protected neurons against cell death induced by these apoptosis-inducing ligands. A protective role of caspase 8 deletion in vivo was also demonstrated using a controlled cortical impact (CCI) model of traumatic brain injury (TBI) and seizure-induced brain injury caused by kainic acid (KA). Morphometric analyses were performed using digital imaging in conjunction with image analysis algorithms. By employing virtual images of hundreds of brain sections, we were able to perform quantitative morphometry of histological and immunohistochemical staining data in an unbiased manner. In the TBI model, homozygous deletion of caspase 8 resulted in reduced lesion volumes, improved post-injury motor performance, superior learning and memory retention, decreased apoptosis, diminished proteolytic processing of caspases and caspase substrates, and less neuronal degeneration, compared to wild type, homozygous cre, and caspase 8-floxed control mice. In the KA model, Ncasp8−/− mice demonstrated superior survival, reduced seizure severity, less apoptosis, and reduced caspase 3 processing. Uninjured aged knockout mice showed improved learning and memory, implicating a possible role for caspase 8 in cognitive decline with aging. Conclusions Neuron-specific deletion of caspase 8 reduces brain damage and improves post-traumatic functional outcomes, suggesting an important role for this caspase in pathophysiology of acute brain trauma.
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Affiliation(s)
- Maryla Krajewska
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Zerong You
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Juan Rong
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Christina Kress
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Xianshu Huang
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Jinsheng Yang
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Tiffany Kyoda
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Ricardo Leyva
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Steven Banares
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Yue Hu
- Department of Anesthesiology, University of California San Diego, La Jolla, California, United States of America
- VA San Diego Healthcare System, San Diego, California, United States of America
| | - Chia-Hung Sze
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Michael J. Whalen
- Neuroscience Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Leonardo Salmena
- Department of Medical Biophysics, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Razqallah Hakem
- Department of Medical Biophysics, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Brian P. Head
- Department of Anesthesiology, University of California San Diego, La Jolla, California, United States of America
| | - John C. Reed
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
- * E-mail: (SK); (JCR)
| | - Stan Krajewski
- Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
- * E-mail: (SK); (JCR)
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Roltsch E, Holcomb L, Young KA, Marks A, Zimmer DB. PSAPP mice exhibit regionally selective reductions in gliosis and plaque deposition in response to S100B ablation. J Neuroinflammation 2010; 7:78. [PMID: 21080947 PMCID: PMC2996465 DOI: 10.1186/1742-2094-7-78] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 11/16/2010] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Numerous studies have reported that increased expression of S100B, an intracellular Ca2+ receptor protein and secreted neuropeptide, exacerbates Alzheimer's disease (AD) pathology. However, the ability of S100B inhibitors to prevent/reverse AD histopathology remains controversial. This study examines the effect of S100B ablation on in vivo plaque load, gliosis and dystrophic neurons. METHODS Because S100B-specific inhibitors are not available, genetic ablation was used to inhibit S100B function in the PSAPP AD mouse model. The PSAPP/S100B-/- line was generated by crossing PSAPP double transgenic males with S100B-/- females and maintained as PSAPP/S100B+/- crosses. Congo red staining was used to quantify plaque load, plaque number and plaque size in 6 month old PSAPP and PSAPP/S100B-/- littermates. The microglial marker Iba1 and astrocytic marker glial fibrillary acidic protein (GFAP) were used to quantify gliosis. Dystrophic neurons were detected with the phospho-tau antibody AT8. S100B immunohistochemistry was used to assess the spatial distribution of S100B in the PSAPP line. RESULTS PSAPP/S100B-/- mice exhibited a regionally selective decrease in cortical but not hippocampal plaque load when compared to PSAPP littermates. This regionally selective reduction in plaque load was accompanied by decreases in plaque number, GFAP-positive astrocytes, Iba1-positive microglia and phospho-tau positive dystrophic neurons. These effects were not attributable to regional variability in the distribution of S100B. Hippocampal and cortical S100B immunoreactivity in PSAPP mice was associated with plaques and co-localized with astrocytes and microglia. CONCLUSIONS Collectively, these data support S100B inhibition as a novel strategy for reducing cortical plaque load, gliosis and neuronal dysfunction in AD and suggest that both extracellular as well as intracellular S100B contribute to AD histopathology.
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Affiliation(s)
- Emily Roltsch
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
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Peña F, Ordaz B, Balleza-Tapia H, Bernal-Pedraza R, Márquez-Ramos A, Carmona-Aparicio L, Giordano M. Beta-amyloid protein (25-35) disrupts hippocampal network activity: role of Fyn-kinase. Hippocampus 2010; 20:78-96. [PMID: 19294646 DOI: 10.1002/hipo.20592] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Early cognitive deficit characteristic of early Alzheimer's disease seems to be produced by the soluble forms of beta-amyloid protein. Such cognitive deficit correlates with neuronal network dysfunction that is reflected as alterations in the electroencephalogram of both Alzheimer patients and transgenic murine models of such disease. Correspondingly, recent studies have demonstrated that chronic exposure to betaAP affects hippocampal oscillatory properties. However, it is still unclear if such neuronal network dysfunction results from a direct action of betaAP on the hippocampal circuit or it is secondary to the chronic presence of the protein in the brain. Therefore, we aimed to explore the effect of acute exposure to betaAP(25-35) on hippocampal network activity both in vitro and in vivo, as well as on intrinsic and synaptic properties of hippocampal neurons. We found that betaAP(25-35), reversibly, affects spontaneous hippocampal population activity in vitro. Such effect is not produced by the inverse sequence betaAP(35-25) and is reproduced by the full-length peptide betaAP(1-42). Correspondingly betaAP(25-35), but not the inverse sequence betaAP(35-25), reduces theta-like activity recorded from the hippocampus in vivo. The betaAP(25-35)-induced disruption in hippocampal network activity correlates with a reduction in spontaneous neuronal activity and synaptic transmission, as well as with an inhibition in the subthreshold oscillations produced by pyramidal neurons in vitro. Finally, we studied the involvement of Fyn-kinase on the betaAP(25-35)-induced disruption in hippocampal network activity in vitro. Interestingly, we found that such phenomenon is not observed in slices obtained from Fyn-knockout mice. In conclusion, our data suggest that betaAP acutely affects proper hippocampal function through a Fyn-dependent mechanism. We propose that such alteration might be related to the cognitive impairment observed, at least, during the early phases of Alzheimer's disease.
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Affiliation(s)
- Fernando Peña
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados Sede Sur, México, D.F., México.
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Guo H, Singh I, Wang Y, Deane R, Barrett T, Fernández JA, Chow N, Griffin JH, Zlokovic BV. Neuroprotective activities of activated protein C mutant with reduced anticoagulant activity. Eur J Neurosci 2009; 29:1119-30. [PMID: 19302148 DOI: 10.1111/j.1460-9568.2009.06664.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The anticoagulant activated protein C (APC) protects neurons and endothelium via protease activated receptor (PAR)1, PAR3 and endothelial protein C receptor. APC is neuroprotective in stroke models. Bleeding complications may limit the pharmacologic utility of APC. Here, we compared the 3K3A-APC mutant with 80% reduced anticoagulant activity and wild-type (wt)-APC. Murine 3K3A-APC compared with wt-APC protected mouse cortical neurons from N-methyl-D-aspartate-induced apoptosis with twofold greater efficacy and more potently reduced N-methyl-D-aspartate excitotoxic lesions in vivo. Human 3K3A-APC protected human brain endothelial cells (BECs) from oxygen/glucose deprivation with 1.7-fold greater efficacy than wt-APC. 3K3A-APC neuronal protection required PAR1 and PAR3, as shown by using PAR-specific blocking antibodies and PAR1- and PAR3-deficient cells and mice. BEC protection required endothelial protein C receptor and PAR1. In neurons and BECs, 3K3A-APC blocked caspase-9 and -3 activation and induction of p53, and decreased the Bax/Bcl-2 pro-apoptotic ratio. After distal middle cerebral artery occlusion (dMCAO) in mice, murine 3K3A-APC compared with vehicle given 4:00 h after dMCAO improved the functional outcome and reduced the infarction volume by 50% within 3 days. 3K3A-APC compared with wt-APC multi-dosing therapy at 12:00 h, 1, 3, 5 and 7 days after dMCAO significantly improved functional recovery and reduced the infarction volume by 75% and 38%, respectively, within 7 days. The wt-APC, but not 3K3A-APC, significantly increased the risk of intracerebral bleeding as indicated by a 50% increase in hemoglobin levels in the ischemic hemisphere. Thus, 3K3A-APC offers a new approach for safer and more efficacious treatments of neurodegenerative disorders and stroke with APC.
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Affiliation(s)
- Huang Guo
- Department for Neurosurgery and Neurology, Center for Neurodegenerative and Vascular Brain Disorders, University of Rochester Medical Center, Rochester, NY 14642, USA
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Cell Cycle Activation and CNS Injury. Neurotox Res 2009; 16:221-37. [PMID: 19526282 DOI: 10.1007/s12640-009-9050-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 03/26/2009] [Accepted: 03/26/2009] [Indexed: 12/28/2022]
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Chen J, Herrup K. Selective vulnerability of neurons in primary cultures and in neurodegenerative diseases. Rev Neurosci 2009; 19:317-26. [PMID: 19145987 DOI: 10.1515/revneuro.2008.19.4-5.317] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Primary neuronal cultures are commonly used to dissect the molecular and cellular mechanisms that underlie human brain diseases. Neurons dissociated from an embryonic brain and grown in culture dishes are almost by definition different from those residing inside a living brain. Not only are the individual cells stripped of their normal chemical and physical contacts, but the cellular composition of the cultures (the ratio of cell types) can be affected by many intrinsic and extrinsic factors, including brain region, neuronal birthday, gender, genetic background and in vitro age. Changes in any of these factors may have a strong impact on the outcome of the experiment. In a recent study, Romito-DiGiacomo et al. /54/ demonstrated that when neurons were harvested from murine embryonic cortex, the typical protocol favored cells that were just finishing cell division at the time of harvest. By taking advantage of the fact that the date of the final cell division (birthday) of a neuron correlates with its final position in the cortical plate they were able to assay deeper layer neurons (layers V-VI) separately from the more superficial layers (layers II-III). They reported that while the superficial cells were sensitive to the toxic effect of beta-amyloid, the deeper layer neurons were virtually resistant to death in its presence. The findings recapitulate selective vulnerability in the neocortex of Alzheimer's disease. This is a beautiful example of how to turn the apparent weakness of primary cultures into strength through experimental design and data interpretation. Selective vulnerability is a common feature of neurodegenerative disease, thus it is critical to use the right primary culture. Do you know what is in your culture?
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Affiliation(s)
- Jianmin Chen
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08901, USA
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Rocher AB, Kinson MS, Luebke JI. Significant structural but not physiological changes in cortical neurons of 12-month-old Tg2576 mice. Neurobiol Dis 2008; 32:309-18. [PMID: 18721884 DOI: 10.1016/j.nbd.2008.07.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 06/26/2008] [Accepted: 07/25/2008] [Indexed: 11/29/2022] Open
Abstract
Amyloid-beta (Abeta) plays a key role in the etiology of Alzheimer's disease, and pyramidal cell dendrites exposed to Abeta exhibit dramatic structural alterations, including reduced dendritic spine densities. To determine whether such structural alterations lead to electrophysiological changes, whole-cell patch clamp recordings with biocytin filling were used to assess both the electrophysiological and morphological properties of layer 3 pyramidal cells in frontal cortical slices prepared from 12-month-old Tg2576 amyloid precursor protein (APP) mutant vs. wild-type (Wt) mice. Tg2576 cells exhibited significantly increased dendritic lengths and volumes and decreased spine densities, while the total number of spines was not different from Wt. Tg2576 and Wt cells did not differ with regard to passive membrane, action potential firing or glutamatergic spontaneous excitatory postsynaptic current properties. Thus, overexpression of mutated APP in young Tg2576 mice leads to significant changes in neuronal morphological properties which do not have readily apparent functional consequences.
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Affiliation(s)
- Anne B Rocher
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118, USA
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Small DH. Network dysfunction in Alzheimer's disease: does synaptic scaling drive disease progression? Trends Mol Med 2008; 14:103-8. [PMID: 18262842 DOI: 10.1016/j.molmed.2007.12.006] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 12/20/2007] [Accepted: 12/20/2007] [Indexed: 11/29/2022]
Abstract
Accumulation of beta-amyloid protein (Abeta) in the brain is a key feature of Alzheimer's disease (AD). The build-up of aggregated forms of Abeta leads to synaptic loss and to cognitive dysfunction. Although the pathways controlling production and aggregation of Abeta are well studied, the mechanisms that drive the spread of neurodegeneration in the brain are unclear. Here, the idea is presented that AD progresses as a consequence of synaptic scaling, a type of neuronal plasticity that helps maintain synaptic signal strength. Recent studies indicate that brain-derived neurotrophic factor, tumour necrosis factor-alpha and alpha7 nicotinic acetylcholine receptors (alpha7 nAChRs) regulate synaptic scaling in the AD brain. It is suggested that further studies on synaptic scaling in AD could reveal new targets for therapeutic drug development.
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Affiliation(s)
- David H Small
- Menzies Research Institute, University of Tasmania, Hobart 7000, Tasmania, Australia.
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