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Kikuchi M, Viet J, Nagata K, Sato M, David G, Audic Y, Silverman MA, Yamamoto M, Akatsu H, Hashizume Y, Takeda S, Akamine S, Miyamoto T, Uozumi R, Gotoh S, Mori K, Ikeda M, Paillard L, Morihara T. Gene-gene functional relationships in Alzheimer's disease: CELF1 regulates KLC1 alternative splicing. Biochem Biophys Res Commun 2024; 721:150025. [PMID: 38768546 DOI: 10.1016/j.bbrc.2024.150025] [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: 02/19/2024] [Revised: 04/16/2024] [Accepted: 04/26/2024] [Indexed: 05/22/2024]
Abstract
The causes of Alzheimer's disease (AD) are poorly understood, although many genes are known to be involved in this pathology. To gain insights into the underlying molecular mechanisms, it is essential to identify the relationships between individual AD genes. Previous work has shown that the splice variant E of KLC1 (KLC1_vE) promotes AD, and that the CELF1 gene, which encodes an RNA-binding protein involved in splicing regulation, is at a risk locus for AD. Here, we identified a functional link between CELF1 and KLC1 in AD pathogenesis. Transcriptomic data from human samples from different ethnic groups revealed that CELF1 mRNA levels are low in AD brains, and the splicing pattern of KLC1 is strongly correlated with CELF1 expression levels. Specifically, KLC1_vE is negatively correlated with CELF1. Depletion and overexpression experiments in cultured cells demonstrated that the CELF1 protein down-regulates KLC1_vE. In a cross-linking and immunoprecipitation sequencing (CLIP-seq) database, CELF1 directly binds to KLC1 RNA, following which it likely modulates terminal exon usage, hence KLC1_vE formation. These findings reveal a new pathogenic pathway where a risk allele of CELF1 is associated with reduced CELF1 expression, which up-regulates KLC1_vE to promote AD.
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Affiliation(s)
- Masataka Kikuchi
- Department of Genome Informatics, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Justine Viet
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes), UMR 6290, F-35000, Rennes, France
| | - Kenichi Nagata
- Department of Functional Anatomy and Neuroscience, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Masahiro Sato
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Geraldine David
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes), UMR 6290, F-35000, Rennes, France
| | - Yann Audic
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes), UMR 6290, F-35000, Rennes, France
| | - Michael A Silverman
- Department of Biological Sciences, Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, Canada
| | - Mitsuko Yamamoto
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Hiroyasu Akatsu
- Department of Community-based Medical Education, Graduate School of Medicine, Nagoya City University, Nagoya, Japan; Choju Medical/Neuropathological Institute, Fukushimura Hospital, Toyohashi, Japan
| | | | - Shuko Takeda
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka University, Suita, Japan; Osaka Psychiatric Medical Center, Osaka Psychiatric Research Center, Hirakata, Japan
| | - Shoshin Akamine
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Tesshin Miyamoto
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Ryota Uozumi
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Shiho Gotoh
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Kohji Mori
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Manabu Ikeda
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Luc Paillard
- Université de Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes), UMR 6290, F-35000, Rennes, France.
| | - Takashi Morihara
- Department of Psychiatry, Graduate School of Medicine, Osaka University, Suita, Japan; Toyonaka Municipal Hospital, Toyonaka, Japan.
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Feole M, Pozo Devoto VM, Dragišić N, Arnaiz C, Bianchelli J, Texlová K, Kovačovicova K, Novotny JS, Havas D, Falzone TL, Stokin GB. Swedish Alzheimer's disease variant perturbs activity of retrograde molecular motors and causes widespread derangement of axonal transport pathways. J Biol Chem 2024; 300:107137. [PMID: 38447793 PMCID: PMC10997842 DOI: 10.1016/j.jbc.2024.107137] [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: 01/12/2024] [Revised: 02/14/2024] [Accepted: 02/16/2024] [Indexed: 03/08/2024] Open
Abstract
Experimental studies in flies, mice, and humans suggest a significant role of impaired axonal transport in the pathogenesis of Alzheimer's disease (AD). The mechanisms underlying these impairments in axonal transport, however, remain poorly understood. Here we report that the Swedish familial AD mutation causes a standstill of the amyloid precursor protein (APP) in the axons at the expense of its reduced anterograde transport. The standstill reflects the perturbed directionality of the axonal transport of APP, which spends significantly more time traveling in the retrograde direction. This ineffective movement is accompanied by an enhanced association of dynactin-1 with APP, which suggests that reduced anterograde transport of APP is the result of enhanced activation of the retrograde molecular motor dynein by dynactin-1. The impact of the Swedish mutation on axonal transport is not limited to the APP vesicles since it also reverses the directionality of a subset of early endosomes, which become enlarged and aberrantly accumulate in distal locations. In addition, it also reduces the trafficking of lysosomes due to their less effective retrograde movement. Altogether, our experiments suggest a pivotal involvement of retrograde molecular motors and transport in the mechanisms underlying impaired axonal transport in AD and reveal significantly more widespread derangement of axonal transport pathways in the pathogenesis of AD.
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Affiliation(s)
- Monica Feole
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St Anne's University Hospital, Brno, Czech Republic; Faculty of Medicine, Department of Biology, Masaryk University, Brno, Czech Republic; School of Cardiovascular and Metabolic Medicine & Sciences, King's College London, London, UK
| | - Victorio M Pozo Devoto
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St Anne's University Hospital, Brno, Czech Republic
| | - Neda Dragišić
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St Anne's University Hospital, Brno, Czech Republic
| | - Cayetana Arnaiz
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA-CONICET-MPSP), Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Julieta Bianchelli
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA-CONICET-MPSP), Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Kateřina Texlová
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St Anne's University Hospital, Brno, Czech Republic; PsychoGenics, Paramus, New Jersey, USA
| | | | - Jan S Novotny
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St Anne's University Hospital, Brno, Czech Republic; Institute for Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Olomouc, Czech Republic
| | | | - Tomas L Falzone
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA-CONICET-MPSP), Partner Institute of the Max Planck Society, Buenos Aires, Argentina; Instituto de Biología Celular y Neurociencia IBCN (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gorazd B Stokin
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St Anne's University Hospital, Brno, Czech Republic; Institute for Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Olomouc, Czech Republic; Division of Neurology, University Medical Centre, Ljubljana, Slovenia; Department of Neurosciences, Mayo Clinic, Rochester, Minnesota, USA.
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Elizaldi SR, Hawes CE, Verma A, Dinasarapu AR, Lakshmanappa YS, Schlegel BT, Rajasundaram D, Li J, Durbin-Johnson BP, Ma ZM, Beckman D, Ott S, Lifson J, Morrison JH, Iyer SS. CCR7+ CD4 T Cell Immunosurveillance Disrupted in Chronic SIV-Induced Neuroinflammation in Rhesus Brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.28.555037. [PMID: 37693567 PMCID: PMC10491118 DOI: 10.1101/2023.08.28.555037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
CD4 T cells survey and maintain immune homeostasis in the brain, yet their differentiation states and functional capabilities remain unclear. Our approach, combining single-cell transcriptomic analysis, ATAC-seq, spatial transcriptomics, and flow cytometry, revealed a distinct subset of CCR7+ CD4 T cells resembling lymph node central memory (T CM ) cells. We observed chromatin accessibility at the CCR7, CD28, and BCL-6 loci, defining molecular features of T CM . Brain CCR7+ CD4 T cells exhibited recall proliferation and interleukin-2 production ex vivo, showcasing their functional competence. We identified the skull bone marrow as a local niche for these cells alongside other CNS border tissues. Sequestering T CM cells in lymph nodes using FTY720 led to reduced CCR7+ CD4 T cell frequencies in the cerebrospinal fluid, accompanied by increased monocyte levels and soluble markers indicating immune activation. In macaques chronically infected with SIVCL57 and experiencing viral rebound due to cessation of antiretroviral therapy, a decrease in brain CCR7+ CD4 T cells was observed, along with increased microglial activation and initiation of neurodegenerative pathways. Our findings highlight a role for CCR7+ CD4 T cells in CNS immune surveillance and their decline during chronic SIV-induced neuroinflammation highlights their responsiveness to neuroinflammatory processes. GRAPHICAL ABSTRACT In Brief Utilizing single-cell and spatial transcriptomics on adult rhesus brain, we uncover a unique CCR7+ CD4 T cell subset resembling central memory T cells (T CM ) within brain and border tissues, including skull bone marrow. Our findings show decreased frequencies of this subset during SIV- induced chronic neuroinflammation, emphasizing responsiveness of CCR7+ CD4 T cells to CNS disruptions. Highlights CCR7+ CD4 T cells survey border and parenchymal CNS compartments during homeostasis; reduced presence of CCR7+ CD4 T cells in cerebrospinal fluid leads to immune activation, implying a role in neuroimmune homeostasis. CNS CCR7+ CD4 T cells exhibit phenotypic and functional features of central memory T cells (T CM ) including production of interleukin 2 and the capacity for rapid recall proliferation. Furthermore, CCR7+ CD4 T cells reside in the skull bone marrow. CCR7+ CD4 T cells are markedly decreased within the brain parenchyma during chronic viral neuroinflammation.
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Chen XQ, Sawa M, Becker A, Karachentsev D, Zuo X, Rynearson KD, Tanzi RE, Mobley WC. Retromer Proteins Reduced in Down Syndrome and the Dp16 Model: Impact of APP Dose and Preclinical Studies of a γ-Secretase Modulator. Ann Neurol 2023; 94:245-258. [PMID: 37042072 DOI: 10.1002/ana.26659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/11/2023] [Accepted: 03/28/2023] [Indexed: 04/13/2023]
Abstract
OBJECTIVE The retromer complex plays an essential role in intracellular endosomal sorting. Deficits in the retromer complex are linked to enhanced Aβ production. The levels of the components of the retromer complex are reported to be downregulated in Alzheimer disease (AD). Down syndrome (DS) shares neuropathological features with AD. Recent evidence points to dysregulation of the retromer complex in DS. The mechanisms underlying retromer deficits in DS and AD are poorly understood. METHODS We measured the levels of retromer components in the frontal cortex of cases of DS-AD (AD in DS) as well as DS; the frontal cortex of a person partially trisomic (PT-DS) for human chromosome 21 (HSA21), whose genome had only the normal 2 copies of the APP gene, was also examined. We also analyzed these proteins in the Dp16 mouse model of DS. To further explore the molecular mechanism for changes in the retromer complex, we treated Dp16 mice with a γ-secretase modulator (GSM; 776890), a treatment that reduces the levels of Aβ42 and Aβ40. RESULTS We found VPS26A, VPS26B, and VPS29, but not VPS35, were significantly reduced in both DS and DS-AD, but not in PT-DS. Downregulation of VPS26A, VPS26B, and VPS29 was recapitulated in the brains of old Dp16 mice (at 16 months of age) and required increased App gene dose. Significantly, GSM treatment completely prevented reductions of the retromer complex. INTERPRETATION Our studies point to increased APP gene dose as a compromising retromer function in DS and suggest a causal role for Aβ42 and Aβ40. ANN NEUROL 2023;94:245-258.
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Affiliation(s)
- Xu-Qiao Chen
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Mariko Sawa
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Ann Becker
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Dmitry Karachentsev
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Xinxin Zuo
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Kevin D Rynearson
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, McCance Center for Brain Health, Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - William C Mobley
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
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Chen XQ, Zuo X, Becker A, Head E, Mobley WC. Reduced synaptic proteins and SNARE complexes in Down syndrome with Alzheimer's disease and the Dp16 mouse Down syndrome model: Impact of APP gene dose. Alzheimers Dement 2023; 19:2095-2116. [PMID: 36370135 PMCID: PMC10175517 DOI: 10.1002/alz.12835] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/22/2022] [Accepted: 09/13/2022] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Synaptic failure, a hallmark of Alzheimer's disease (AD), is correlated with reduced levels of synaptic proteins. Though people with Down syndrome (DS) are at markedly increased risk for AD (AD-DS), few studies have addressed synapse dysfunction. METHODS Synaptic proteins were measured in the frontal cortex of DS, AD-DS, sporadic AD cases, and controls. The same proteins were examined in the Dp16 model of DS. RESULTS A common subset of synaptic proteins were reduced in AD and AD-DS, but not in DS or a case of partial trisomy 21 lacking triplication of APP gene. Pointing to compromised synaptic function, the reductions in AD and AD-DS were correlated with reduced SNARE complexes. In Dp16 mice reductions in syntaxin 1A, SNAP25 and the SNARE complex recapitulated findings in AD-DS; reductions were impacted by both age and increased App gene dose. DISCUSSION Synaptic phenotypes shared between AD-DS and AD point to shared pathogenetic mechanisms.
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Affiliation(s)
- Xu-Qiao Chen
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Xinxin Zuo
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Ann Becker
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Elizabeth Head
- Department of Pathology & Laboratory Medicine, University of California Irvine, Irvine, CA 92697, USA
| | - William C Mobley
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
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Ramamoorthy K, Yoshimura R, Al-Juburi S, Anandam KY, Kapadia R, Alachkar A, Abbott GW, Said HM. Alzheimer's disease is associated with disruption in thiamin transport physiology: A potential role for neuroinflammation. Neurobiol Dis 2022; 171:105799. [PMID: 35750148 PMCID: PMC9744268 DOI: 10.1016/j.nbd.2022.105799] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/30/2022] [Accepted: 06/17/2022] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by Amyloid-β peptide (Aβ) containing plaques and cognitive deficits. The pathophysiology of AD also involves neuroinflammation. Vitamin B1 (thiamin) is indispensable for normal cellular energy metabolism. Thiamin homeostasis is altered in AD, and its deficiency is known to aggravate AD pathology. Little, however, is known about possible alterations in level of expression of thiamin transporters-1 and -2 (THTR-1 and -2) in the brain of AD, and whether pro-inflammatory cytokines affect thiamin uptake by brain cells. We addressed these issues using brain tissue samples [prefrontal cortex (PFC) and hippocampus (HIP)] from AD patients and from 5XFAD mouse model of AD, together with cultured human neuroblastoma SH-SY5Y cells as model. Our results revealed a significantly lower expression of both THTR-1 and THTR-2 in the PFC and HIP of AD patients and 5XFAD mouse model of AD compared to appropriate normal controls. Further, we found that exposure of the SH-SY5Y cells to pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) led to a significant inhibition in thiamin uptake. Focusing on IL-1β, we found the inhibition in thiamin uptake to be time-dependent and reversible; it was also associated with a substantial reduction in expression of THTR-1 (but not THTR-2) protein and mRNA as well as a decrease in promoter activity of the SLC19A2 gene (which encodes THTR-1). Finally, using transcriptomic analysis, we found that thiamin availability in SH-SY5Y cells caused changes in the expression of genes relevant to AD pathways. These studies demonstrate, for the first time, that thiamin transport physiology/molecular biology parameters are negatively impacted in AD brain and that pro-inflammatory cytokines inhibit thiamin uptake by neuroblastoma cells. The results also support a possible role for thiamin in the pathophysiology of AD.
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Affiliation(s)
- Kalidas Ramamoorthy
- Departments of Physiology & Biophysics, University of California, Irvine, CA 92697, United States of America
| | - Ryan Yoshimura
- Departments of Physiology & Biophysics, University of California, Irvine, CA 92697, United States of America
| | - Saleh Al-Juburi
- Departments of Physiology & Biophysics, University of California, Irvine, CA 92697, United States of America
| | - Kasin Y Anandam
- Departments of Physiology & Biophysics, University of California, Irvine, CA 92697, United States of America
| | - Rubina Kapadia
- Medicine, School of Medicine, University of California, Irvine, CA 92697, United States of America
| | - Amal Alachkar
- Department of Pharmaceutical Sciences, University of California, Irvine, CA 92697, United States of America
| | - Geoffrey W Abbott
- Departments of Physiology & Biophysics, University of California, Irvine, CA 92697, United States of America
| | - Hamid M Said
- Departments of Physiology & Biophysics, University of California, Irvine, CA 92697, United States of America; Medicine, School of Medicine, University of California, Irvine, CA 92697, United States of America; Department of Veteran Affairs, VA Medical Center, Long Beach, CA 90822, United States of America.
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