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Milioto C, Carcolé M, Giblin A, Coneys R, Attrebi O, Ahmed M, Harris SS, Lee BI, Yang M, Ellingford RA, Nirujogi RS, Biggs D, Salomonsson S, Zanovello M, de Oliveira P, Katona E, Glaria I, Mikheenko A, Geary B, Udine E, Vaizoglu D, Anoar S, Jotangiya K, Crowley G, Smeeth DM, Adams ML, Niccoli T, Rademakers R, van Blitterswijk M, Devoy A, Hong S, Partridge L, Coyne AN, Fratta P, Alessi DR, Davies B, Busche MA, Greensmith L, Fisher EMC, Isaacs AM. PolyGR and polyPR knock-in mice reveal a conserved neuroprotective extracellular matrix signature in C9orf72 ALS/FTD neurons. Nat Neurosci 2024; 27:643-655. [PMID: 38424324 PMCID: PMC11001582 DOI: 10.1038/s41593-024-01589-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 01/24/2024] [Indexed: 03/02/2024]
Abstract
Dipeptide repeat proteins are a major pathogenic feature of C9orf72 amyotrophic lateral sclerosis (C9ALS)/frontotemporal dementia (FTD) pathology, but their physiological impact has yet to be fully determined. Here we generated C9orf72 dipeptide repeat knock-in mouse models characterized by expression of 400 codon-optimized polyGR or polyPR repeats, and heterozygous C9orf72 reduction. (GR)400 and (PR)400 knock-in mice recapitulate key features of C9ALS/FTD, including cortical neuronal hyperexcitability, age-dependent spinal motor neuron loss and progressive motor dysfunction. Quantitative proteomics revealed an increase in extracellular matrix (ECM) proteins in (GR)400 and (PR)400 spinal cord, with the collagen COL6A1 the most increased protein. TGF-β1 was one of the top predicted regulators of this ECM signature and polyGR expression in human induced pluripotent stem cell neurons was sufficient to induce TGF-β1 followed by COL6A1. Knockdown of TGF-β1 or COL6A1 orthologues in polyGR model Drosophila exacerbated neurodegeneration, while expression of TGF-β1 or COL6A1 in induced pluripotent stem cell-derived motor neurons of patients with C9ALS/FTD protected against glutamate-induced cell death. Altogether, our findings reveal a neuroprotective and conserved ECM signature in C9ALS/FTD.
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Affiliation(s)
- Carmelo Milioto
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Mireia Carcolé
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Ashling Giblin
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UCL Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Rachel Coneys
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Olivia Attrebi
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Mhoriam Ahmed
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Samuel S Harris
- UK Dementia Research Institute, University College London, London, UK
| | - Byung Il Lee
- UK Dementia Research Institute, University College London, London, UK
| | - Mengke Yang
- UK Dementia Research Institute, University College London, London, UK
| | | | - Raja S Nirujogi
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Daniel Biggs
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Sally Salomonsson
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Matteo Zanovello
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Paula de Oliveira
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Eszter Katona
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Idoia Glaria
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- Research Support Service, Institute of Agrobiotechnology, CSIC-Government of Navarra, Mutilva, Spain
| | - Alla Mikheenko
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Bethany Geary
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Evan Udine
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Deniz Vaizoglu
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Sharifah Anoar
- UCL Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Khrisha Jotangiya
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Gerard Crowley
- UK Dementia Research Institute, University College London, London, UK
| | - Demelza M Smeeth
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Mirjam L Adams
- UK Dementia Research Institute, University College London, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Teresa Niccoli
- UCL Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Rosa Rademakers
- VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | | | - Anny Devoy
- UK Dementia Research Institute, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Soyon Hong
- UK Dementia Research Institute, University College London, London, UK
| | - Linda Partridge
- UCL Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Alyssa N Coyne
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Pietro Fratta
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, London, UK
| | - Dario R Alessi
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Ben Davies
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
- Francis Crick Institute, London, UK
| | - Marc Aurel Busche
- UK Dementia Research Institute, University College London, London, UK
| | - Linda Greensmith
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, London, UK
| | - Elizabeth M C Fisher
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK.
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, London, UK.
| | - Adrian M Isaacs
- UK Dementia Research Institute, University College London, London, UK.
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK.
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, London, UK.
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2
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Tsintzas E, Niccoli T. Using Drosophila amyloid toxicity models to study Alzheimer's disease. Ann Hum Genet 2024. [PMID: 38517001 DOI: 10.1111/ahg.12554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 01/28/2024] [Accepted: 01/29/2024] [Indexed: 03/23/2024]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia and is characterised by a progressive loss of neurons, which manifests as gradual memory decline, followed by cognitive loss. Despite the significant progress in identifying novel biomarkers and understanding the prodromal pathology and symptomatology, AD remains a significant unmet clinical need. Lecanemab and aducanumab, the only Food and Drug Administration approved drugs to exhibit some disease-modifying clinical efficacy, target Aβ amyloid, underscoring the importance of this protein in disease aetiology. Nevertheless, in the absence of a definitive cure, the utilisation of preclinical models remains imperative for the identification of novel therapeutic targets and the evaluation of potential therapeutic agents. Drosophila melanogaster is a model system that can be used as a research tool to investigate neurodegeneration and therapeutic interventions. The short lifespan, low price and ease of husbandry/rearing make Drosophila an advantageous model organism from a practical perspective. However, it is the highly conserved genome and similarity of Drosophila and human neurobiology which make flies a powerful tool to investigate neurodegenerative mechanisms. In addition, the ease of transgenic modifications allows for early proof of principle studies for future therapeutic approaches in neurodegenerative research. This mini review will specifically focus on utilising Drosophila as an in vivo model of amyloid toxicity in AD.
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Affiliation(s)
- Elli Tsintzas
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
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Xu D, Vincent A, González-Gutiérrez A, Aleyakpo B, Anoar S, Giblin A, Atilano ML, Adams M, Shen D, Thoeng A, Tsintzas E, Maeland M, Isaacs AM, Sierralta J, Niccoli T. A monocarboxylate transporter rescues frontotemporal dementia and Alzheimer's disease models. PLoS Genet 2023; 19:e1010893. [PMID: 37733679 PMCID: PMC10513295 DOI: 10.1371/journal.pgen.1010893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 07/29/2023] [Indexed: 09/23/2023] Open
Abstract
Brains are highly metabolically active organs, consuming 20% of a person's energy at resting state. A decline in glucose metabolism is a common feature across a number of neurodegenerative diseases. Another common feature is the progressive accumulation of insoluble protein deposits, it's unclear if the two are linked. Glucose metabolism in the brain is highly coupled between neurons and glia, with glucose taken up by glia and metabolised to lactate, which is then shuttled via transporters to neurons, where it is converted back to pyruvate and fed into the TCA cycle for ATP production. Monocarboxylates are also involved in signalling, and play broad ranging roles in brain homeostasis and metabolic reprogramming. However, the role of monocarboxylates in dementia has not been tested. Here, we find that increasing pyruvate import in Drosophila neurons by over-expression of the transporter bumpel, leads to a rescue of lifespan and behavioural phenotypes in fly models of both frontotemporal dementia and Alzheimer's disease. The rescue is linked to a clearance of late stage autolysosomes, leading to degradation of toxic peptides associated with disease. We propose upregulation of pyruvate import into neurons as potentially a broad-scope therapeutic approach to increase neuronal autophagy, which could be beneficial for multiple dementias.
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Affiliation(s)
- Dongwei Xu
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Alec Vincent
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Andrés González-Gutiérrez
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Benjamin Aleyakpo
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Sharifah Anoar
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Ashling Giblin
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
- UK Dementia Research Institute at UCL, Cruciform Building, London, United Kingdom
| | - Magda L. Atilano
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
- UK Dementia Research Institute at UCL, Cruciform Building, London, United Kingdom
| | - Mirjam Adams
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Dunxin Shen
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Annora Thoeng
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Elli Tsintzas
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Marie Maeland
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Adrian M. Isaacs
- UK Dementia Research Institute at UCL, Cruciform Building, London, United Kingdom
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Jimena Sierralta
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
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Abstract
Frontotemporal dementia (FTD), hallmarked by antero-temporal degeneration in the human brain, is the second most common early onset dementia. FTD is a diverse disease with three main clinical presentations, four different identified proteinopathies and many disease-associated genes. The exact pathophysiology of FTD remains to be elucidated. One common characteristic all forms of FTD share is the dysregulation of glucose metabolism in patients’ brains. The brain consumes around 20% of the body’s energy supply and predominantly utilizes glucose as a fuel. Glucose metabolism dysregulation could therefore be extremely detrimental for neuronal health. Research into the association between glucose metabolism and dementias has recently gained interest in Alzheimer’s disease. FTD also presents with glucose metabolism dysregulation, however, this remains largely an unexplored area. A better understanding of the link between FTD and glucose metabolism may yield further insight into FTD pathophysiology and aid the development of novel therapeutics. Here we review our current understanding of FTD and glucose metabolism in the brain and discuss the evidence of impaired glucose metabolism in FTD. Lastly, we review research potentially suggesting a causal relationship between FTD proteinopathies and impaired glucose metabolism in FTD.
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5
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Anoar S, Woodling NS, Niccoli T. Mitochondria Dysfunction in Frontotemporal Dementia/Amyotrophic Lateral Sclerosis: Lessons From Drosophila Models. Front Neurosci 2021; 15:786076. [PMID: 34899176 PMCID: PMC8652125 DOI: 10.3389/fnins.2021.786076] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/03/2021] [Indexed: 12/16/2022] Open
Abstract
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative disorders characterized by declining motor and cognitive functions. Even though these diseases present with distinct sets of symptoms, FTD and ALS are two extremes of the same disease spectrum, as they show considerable overlap in genetic, clinical and neuropathological features. Among these overlapping features, mitochondrial dysfunction is associated with both FTD and ALS. Recent studies have shown that cells derived from patients' induced pluripotent stem cells (iPSC)s display mitochondrial abnormalities, and similar abnormalities have been observed in a number of animal disease models. Drosophila models have been widely used to study FTD and ALS because of their rapid generation time and extensive set of genetic tools. A wide array of fly models have been developed to elucidate the molecular mechanisms of toxicity for mutations associated with FTD/ALS. Fly models have been often instrumental in understanding the role of disease associated mutations in mitochondria biology. In this review, we discuss how mutations associated with FTD/ALS disrupt mitochondrial function, and we review how the use of Drosophila models has been pivotal to our current knowledge in this field.
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Affiliation(s)
- Sharifah Anoar
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Nathaniel S Woodling
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
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6
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Atilano ML, Grönke S, Niccoli T, Kempthorne L, Hahn O, Morón-Oset J, Hendrich O, Dyson M, Adams ML, Hull A, Salcher-Konrad MT, Monaghan A, Bictash M, Glaria I, Isaacs AM, Partridge L. Enhanced insulin signalling ameliorates C9orf72 hexanucleotide repeat expansion toxicity in Drosophila. eLife 2021; 10:e58565. [PMID: 33739284 PMCID: PMC8007214 DOI: 10.7554/elife.58565] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 03/09/2021] [Indexed: 12/14/2022] Open
Abstract
G4C2 repeat expansions within the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The repeats undergo repeat-associated non-ATG translation to generate toxic dipeptide repeat proteins. Here, we show that insulin/IGF signalling is reduced in fly models of C9orf72 repeat expansion using RNA sequencing of adult brain. We further demonstrate that activation of insulin/IGF signalling can mitigate multiple neurodegenerative phenotypes in flies expressing either expanded G4C2 repeats or the toxic dipeptide repeat protein poly-GR. Levels of poly-GR are reduced when components of the insulin/IGF signalling pathway are genetically activated in the diseased flies, suggesting a mechanism of rescue. Modulating insulin signalling in mammalian cells also lowers poly-GR levels. Remarkably, systemic injection of insulin improves the survival of flies expressing G4C2 repeats. Overall, our data suggest that modulation of insulin/IGF signalling could be an effective therapeutic approach against C9orf72 ALS/FTD.
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Affiliation(s)
- Magda L Atilano
- Department of Genetics, Evolution and Environment, Institute of Healthy AgeingLondonUnited Kingdom
- UK Dementia Research Institute at UCLLondonUnited Kingdom
| | | | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy AgeingLondonUnited Kingdom
- UK Dementia Research Institute at UCLLondonUnited Kingdom
| | - Liam Kempthorne
- UK Dementia Research Institute at UCLLondonUnited Kingdom
- Department of Neurodegenerative Disease, UCL Institute of NeurologyLondonUnited Kingdom
| | - Oliver Hahn
- Max Planck Institute for Biology of AgeingCologneGermany
| | | | | | - Miranda Dyson
- Department of Genetics, Evolution and Environment, Institute of Healthy AgeingLondonUnited Kingdom
- UK Dementia Research Institute at UCLLondonUnited Kingdom
| | - Mirjam Lisette Adams
- Department of Genetics, Evolution and Environment, Institute of Healthy AgeingLondonUnited Kingdom
- UK Dementia Research Institute at UCLLondonUnited Kingdom
| | - Alexander Hull
- Department of Genetics, Evolution and Environment, Institute of Healthy AgeingLondonUnited Kingdom
| | - Marie-Therese Salcher-Konrad
- UK Dementia Research Institute at UCLLondonUnited Kingdom
- Department of Neurodegenerative Disease, UCL Institute of NeurologyLondonUnited Kingdom
| | - Amy Monaghan
- Alzheimer's Research United Kingdom UCL Drug Discovery Institute, University College LondonLondonUnited Kingdom
| | - Magda Bictash
- Alzheimer's Research United Kingdom UCL Drug Discovery Institute, University College LondonLondonUnited Kingdom
| | - Idoia Glaria
- UK Dementia Research Institute at UCLLondonUnited Kingdom
- Department of Neurodegenerative Disease, UCL Institute of NeurologyLondonUnited Kingdom
| | - Adrian M Isaacs
- UK Dementia Research Institute at UCLLondonUnited Kingdom
- Department of Neurodegenerative Disease, UCL Institute of NeurologyLondonUnited Kingdom
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy AgeingLondonUnited Kingdom
- Max Planck Institute for Biology of AgeingCologneGermany
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7
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Bolukbasi E, Woodling NS, Ivanov DK, Adcott J, Foley A, Rajasingam A, Gittings LM, Aleyakpo B, Niccoli T, Thornton JM, Partridge L. Cell type-specific modulation of healthspan by Forkhead family transcription factors in the nervous system. Proc Natl Acad Sci U S A 2021; 118:2011491118. [PMID: 33593901 PMCID: PMC7923679 DOI: 10.1073/pnas.2011491118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Reduced activity of insulin/insulin-like growth factor signaling (IIS) increases healthy lifespan among diverse animal species. Downstream of IIS, multiple evolutionarily conserved transcription factors (TFs) are required; however, distinct TFs are likely responsible for these effects in different tissues. Here we have asked which TFs can extend healthy lifespan within distinct cell types of the adult nervous system in Drosophila Starting from published single-cell transcriptomic data, we report that forkhead (FKH) is endogenously expressed in neurons, whereas forkhead-box-O (FOXO) is expressed in glial cells. Accordingly, we find that neuronal FKH and glial FOXO exert independent prolongevity effects. We have further explored the role of neuronal FKH in a model of Alzheimer's disease-associated neuronal dysfunction, where we find that increased neuronal FKH preserves behavioral function and reduces ubiquitinated protein aggregation. Finally, using transcriptomic profiling, we identify Atg17, a member of the Atg1 autophagy initiation family, as one FKH-dependent target whose neuronal overexpression is sufficient to extend healthy lifespan. Taken together, our results underscore the importance of cell type-specific mapping of TF activity to preserve healthy function with age.
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Affiliation(s)
- Ekin Bolukbasi
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Nathaniel S Woodling
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Dobril K Ivanov
- European Bioinformatics Institute, European Molecular Biology Laboratory, Cambridge CB10 1SD, United Kingdom
- UK Dementia Research Institute, Cardiff University, Cardiff CF24 4HQ, United Kingdom
| | - Jennifer Adcott
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Andrea Foley
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Arjunan Rajasingam
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Lauren M Gittings
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Benjamin Aleyakpo
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Teresa Niccoli
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Janet M Thornton
- European Bioinformatics Institute, European Molecular Biology Laboratory, Cambridge CB10 1SD, United Kingdom
| | - Linda Partridge
- Institute of Healthy Ageing, University College London, London WC1E 6BT, United Kingdom;
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
- Department of Biological Mechanisms of Ageing, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
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8
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Niccoli T, Kerr F, Snoeren I, Fabian D, Aleyakpo B, Ivanov D, Sofola-Adesakin O, Cryar A, Adcott J, Thornton J, Partridge L. Activating transcription factor 4-dependent lactate dehydrogenase activation as a protective response to amyloid beta toxicity. Brain Commun 2021; 3:fcab053. [PMID: 33977265 PMCID: PMC8093921 DOI: 10.1093/braincomms/fcab053] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 02/07/2022] [Accepted: 02/09/2021] [Indexed: 12/21/2022] Open
Abstract
Accumulation of amyloid beta peptides is thought to initiate the pathogenesis of Alzheimer's disease. However, the precise mechanisms mediating their neurotoxicity are unclear. Our microarray analyses show that, in Drosophila models of amyloid beta 42 toxicity, genes involved in the unfolded protein response and metabolic processes are upregulated in brain. Comparison with the brain transcriptome of early-stage Alzheimer's patients revealed a common transcriptional signature, but with generally opposing directions of gene expression changes between flies and humans. Among these differentially regulated genes, lactate dehydrogenase (Ldh) was up-regulated by the greatest degree in amyloid beta 42 flies and the human orthologues (LDHA and LDHB) were down-regulated in patients. Functional analyses revealed that either over-expression or inhibition of Ldh by RNA interference (RNAi) slightly exacerbated climbing defects in both healthy and amyloid beta 42-induced Drosophila. This suggests that metabolic responses to lactate dehydrogenase must be finely-tuned, and that its observed upregulation following amyloid beta 42 production could potentially represent a compensatory protection to maintain pathway homeostasis in this model, with further manipulation leading to detrimental effects. The increased Ldh expression in amyloid beta 42 flies was regulated partially by unfolded protein response signalling, as ATF4 RNAi diminished the transcriptional response and enhanced amyloid beta 42-induced climbing phenotypes. Further functional studies are required to determine whether Ldh upregulation provides compensatory neuroprotection against amyloid beta 42-induced loss of activating transcription factor 4 activity and endoplasmatic reticulum stress. Our study thus reveals dysregulation of lactate dehydrogenase signalling in Drosophila models and patients with Alzheimer's disease, which may lead to a detrimental loss of metabolic homeostasis. Importantly, we observed that down-regulation of ATF4-dependent endoplasmic reticulum-stress signalling in this context appears to prevent Ldh compensation and to exacerbate amyloid beta 42-dependent neuronal toxicity. Our findings, therefore, suggest caution in the use of therapeutic strategies focussed on down-regulation of this pathway for the treatment of Alzheimer's disease, since its natural response to the toxic peptide may induce beneficial neuroprotective effects.
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Affiliation(s)
- Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
- Correspondence may also be addressed to: Teresa Niccoli E-mail:
| | - Fiona Kerr
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
- Department of Biological and Biomedical Sciences, School of Health & Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK
- Department of Life Sciences, School of Applied Sciences, Edinburgh Napier University, Edinburgh EH11 4BN, UK
- Correspondence may also be addressed to: Fiona Kerr Department of Life Sciences, School of Applied Sciences, Edinburgh Napier University, Sighthill Campus Edinburgh EH11 4BN, UK E-mail:
| | - Inge Snoeren
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Daniel Fabian
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Benjamin Aleyakpo
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Dobril Ivanov
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
- UK Dementia Research Institute (UKDRI), Cardiff University, Cardiff CF24 4HQ, UK
| | - Oyinkan Sofola-Adesakin
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Adam Cryar
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Jennifer Adcott
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Janet Thornton
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
- Correspondence to: Linda Partridge Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London Darwin Building, Gower Street, London WC1E 6BT, UK E-mail:
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9
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Yu Y, Niccoli T, Ren Z, Woodling NS, Aleyakpo B, Szabadkai G, Partridge L. PICALM rescues glutamatergic neurotransmission, behavioural function and survival in a Drosophila model of Aβ42 toxicity. Hum Mol Genet 2020; 29:2420-2434. [PMID: 32592479 PMCID: PMC7424762 DOI: 10.1093/hmg/ddaa125] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 01/08/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia and the most prevalent neurodegenerative disease. Genome-wide association studies have linked PICALM to AD risk. PICALM has been implicated in Aβ42 production and turnover, but whether it plays a direct role in modulating Aβ42 toxicity remains unclear. We found that increased expression of the Drosophila PICALM orthologue lap could rescue Aβ42 toxicity in an adult-onset model of AD, without affecting Aβ42 level. Imbalances in the glutamatergic system, leading to excessive, toxic stimulation, have been associated with AD. We found that Aβ42 caused the accumulation of presynaptic vesicular glutamate transporter (VGlut) and increased spontaneous glutamate release. Increased lap expression reversed these phenotypes back to control levels, suggesting that lap may modulate glutamatergic transmission. We also found that lap modulated the localization of amphiphysin (Amph), the homologue of another AD risk factor BIN1, and that Amph itself modulated postsynaptic glutamate receptor (GluRII) localization. We propose a model where PICALM modulates glutamatergic transmission, together with BIN1, to ameliorate synaptic dysfunction and disease progression.
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Affiliation(s)
- Yifan Yu
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
- UK Dementia Research Institute at UCL, London WC1E 6BT, UK
| | - Ziyu Ren
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London WC1E 6BT, UK
| | - Nathaniel S Woodling
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Benjamin Aleyakpo
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Gyorgy Szabadkai
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London WC1E 6BT, UK
- The Francis Crick Institute, London NW1 1AT, UK
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
- Max Planck Institute for Biology of Ageing, Cologne 50931, Germany
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10
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Yamada SB, Gendron TF, Niccoli T, Genuth NR, Grosely R, Shi Y, Glaria I, Kramer NJ, Nakayama L, Fang S, Dinger TJI, Thoeng A, Rocha G, Barna M, Puglisi JD, Partridge L, Ichida JK, Isaacs AM, Petrucelli L, Gitler AD. RPS25 is required for efficient RAN translation of C9orf72 and other neurodegenerative disease-associated nucleotide repeats. Nat Neurosci 2019; 22:1383-1388. [PMID: 31358992 PMCID: PMC6713615 DOI: 10.1038/s41593-019-0455-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 06/20/2019] [Indexed: 12/18/2022]
Abstract
Nucleotide repeat expansions in the C9orf72 gene are the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia. Unconventional translation (RAN translation) of C9orf72 repeats generates dipeptide repeat proteins that can cause neurodegeneration. We performed a genetic screen for regulators of RAN translation and identified small ribosomal protein subunit 25 (RPS25), presenting a potential therapeutic target for C9orf72-related amyotrophic lateral sclerosis and frontotemporal dementia and other neurodegenerative diseases caused by nucleotide repeat expansions.
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Affiliation(s)
- Shizuka B Yamada
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Tania F Gendron
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Teresa Niccoli
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Institute of Neurology, London, UK
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Naomi R Genuth
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Rosslyn Grosely
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Yingxiao Shi
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Idoia Glaria
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Institute of Neurology, London, UK
| | - Nicholas J Kramer
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Neurosciences Graduate Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Lisa Nakayama
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Shirleen Fang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Tai J I Dinger
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Annora Thoeng
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Institute of Neurology, London, UK
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Gabriel Rocha
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Maria Barna
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Justin K Ichida
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angeles, CA, USA
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Institute of Neurology, London, UK
| | | | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
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11
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Simone R, Balendra R, Moens TG, Preza E, Wilson KM, Heslegrave A, Woodling NS, Niccoli T, Gilbert-Jaramillo J, Abdelkarim S, Clayton EL, Clarke M, Konrad MT, Nicoll AJ, Mitchell JS, Calvo A, Chio A, Houlden H, Polke JM, Ismail MA, Stephens CE, Vo T, Farahat AA, Wilson WD, Boykin DW, Zetterberg H, Partridge L, Wray S, Parkinson G, Neidle S, Patani R, Fratta P, Isaacs AM. G-quadruplex-binding small molecules ameliorate C9orf72 FTD/ALS pathology in vitro and in vivo. EMBO Mol Med 2019; 10:22-31. [PMID: 29113975 PMCID: PMC5760849 DOI: 10.15252/emmm.201707850] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Intronic GGGGCC repeat expansions in C9orf72 are the most common known cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), which are characterised by degeneration of cortical and motor neurons, respectively. Repeat expansions have been proposed to cause disease by both the repeat RNA forming foci that sequester RNA‐binding proteins and through toxic dipeptide repeat proteins generated by repeat‐associated non‐ATG translation. GGGGCC repeat RNA folds into a G‐quadruplex secondary structure, and we investigated whether targeting this structure is a potential therapeutic strategy. We performed a screen that identified three structurally related small molecules that specifically stabilise GGGGCC repeat G‐quadruplex RNA. We investigated their effect in C9orf72 patient iPSC‐derived motor and cortical neurons and show that they significantly reduce RNA foci burden and the levels of dipeptide repeat proteins. Furthermore, they also reduce dipeptide repeat proteins and improve survival in vivo, in GGGGCC repeat‐expressing Drosophila. Therefore, small molecules that target GGGGCC repeat G‐quadruplexes can ameliorate the two key pathologies associated with C9orf72 FTD/ALS. These data provide proof of principle that targeting GGGGCC repeat G‐quadruplexes has therapeutic potential.
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Affiliation(s)
- Roberto Simone
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Rubika Balendra
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Thomas G Moens
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Elisavet Preza
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Katherine M Wilson
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Amanda Heslegrave
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Nathan S Woodling
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | | | - Samir Abdelkarim
- MRC Centre for Neuromuscular Disease UCL Institute of Neurology, London, UK
| | - Emma L Clayton
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Mica Clarke
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | | | - Andrew J Nicoll
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.,MRC Prion Unit at UCL Institute of Prion Diseases, London, UK
| | - Jamie S Mitchell
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Andrea Calvo
- 'Rita Levi Montalcini' Department of Neuroscience, ALS Centre University of Turin, Turin, Italy
| | - Adriano Chio
- 'Rita Levi Montalcini' Department of Neuroscience, ALS Centre University of Turin, Turin, Italy
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - James M Polke
- Neurogenetics Unit UCL Institute of Neurology, London, UK
| | - Mohamed A Ismail
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Chad E Stephens
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Tam Vo
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | | | - W David Wilson
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - David W Boykin
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Henrik Zetterberg
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK.,Clinical Neurochemistry Laboratory Institute of Neuroscience and Physiology Department of Psychiatry and Neurochemistry The Sahlgrenska Academy University of Gothenburg, Gothenburg, Sweden.,UK Dementia Research Institute at UCL UCL Institute of Neurology, London, UK
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK.,Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Selina Wray
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | | | | | - Rickie Patani
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Pietro Fratta
- MRC Centre for Neuromuscular Disease UCL Institute of Neurology, London, UK
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK .,UK Dementia Research Institute at UCL UCL Institute of Neurology, London, UK
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12
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Abstract
Like many other neurodegenerative diseases, age is a major risk factor in the development of ALS/FTD. But why is this the case? Recent genetic advances have highlighted some of pathways involved in the development of disease, and, strikingly, they appear to substantially overlap with those known to directly modulate the ageing process. Many ALS/FTD linked genes play a direct role in autophagy/lysosomal degradation, one of the most important pathways linked to ageing. However, systemic processes such as inflammation, as well as cellular maintenance pathways, including RNA splicing and nuclear-cytoplasmic transport have been increasingly linked both to disease and ageing. We highlight some of the shared mechanisms between the ageing process itself and emerging pathogenic mechanisms in ALS/FTD.
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Affiliation(s)
- Teresa Niccoli
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, UCL, London WC1E 6BT, UK
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, UCL, London WC1E 6BT, UK.,Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.,UK Dementia Research Institute at UCL, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
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13
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Moens TG, Mizielinska S, Niccoli T, Mitchell JS, Thoeng A, Ridler CE, Grönke S, Esser J, Heslegrave A, Zetterberg H, Partridge L, Isaacs AM. Sense and antisense RNA are not toxic in Drosophila models of C9orf72-associated ALS/FTD. Acta Neuropathol 2018; 135:445-457. [PMID: 29380049 PMCID: PMC6385858 DOI: 10.1007/s00401-017-1798-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 12/18/2017] [Accepted: 12/18/2017] [Indexed: 12/14/2022]
Abstract
A GGGGCC hexanucleotide repeat expansion in the C9orf72 gene is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Neurodegeneration may occur via transcription of the repeats into inherently toxic repetitive sense and antisense RNA species, or via repeat-associated non-ATG initiated translation (RANT) of sense and antisense RNA into toxic dipeptide repeat proteins. We have previously demonstrated that regular interspersion of repeat RNA with stop codons prevents RANT (RNA-only models), allowing us to study the role of repeat RNA in isolation. Here we have created novel RNA-only Drosophila models, including the first models of antisense repeat toxicity, and flies expressing extremely large repeats, within the range observed in patients. We generated flies expressing ~ 100 repeat sense or antisense RNA either as part of a processed polyadenylated transcript or intronic sequence. We additionally created Drosophila expressing > 1000 RNA-only repeats in the sense direction. When expressed in adult Drosophila neurons polyadenylated repeat RNA is largely cytoplasmic in localisation, whilst intronic repeat RNA forms intranuclear RNA foci, as does > 1000 repeat RNA, thus allowing us to investigate both nuclear and cytoplasmic RNA toxicity. We confirmed that these RNA foci are capable of sequestering endogenous Drosophila RNA-binding proteins, and that the production of dipeptide proteins (poly-glycine–proline, and poly-glycine–arginine) is suppressed in our models. We find that neither cytoplasmic nor nuclear sense or antisense RNA are toxic when expressed in adult Drosophila neurons, suggesting they have a limited role in disease pathogenesis.
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Affiliation(s)
- Thomas G Moens
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, WC1E 6BT, UK
| | - Sarah Mizielinska
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 9RT, UK
- UK Dementia Research Institute at King's College London, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, London, SE5 9RT, UK
| | - Teresa Niccoli
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, WC1E 6BT, UK
| | - Jamie S Mitchell
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - Annora Thoeng
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - Charlotte E Ridler
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - Sebastian Grönke
- Max Planck Institute for Biology of Ageing, 50931, Cologne, Germany
| | - Jacqueline Esser
- Max Planck Institute for Biology of Ageing, 50931, Cologne, Germany
| | - Amanda Heslegrave
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, WC1N 1PJ, UK
- UK Dementia Research Institute at UCL, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - Henrik Zetterberg
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, WC1N 1PJ, UK
- Clinical Neurochemistry Laboratory, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- UK Dementia Research Institute at UCL, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, WC1E 6BT, UK.
- Max Planck Institute for Biology of Ageing, 50931, Cologne, Germany.
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK.
- UK Dementia Research Institute at UCL, UCL Institute of Neurology, London, WC1N 3BG, UK.
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14
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Niccoli T, Moens T, Thoeng A, Konrad M, Partridge L, Isaacs AM. [P3–150]: SCREENING FOR MODIFIERS OF C9ORF72 HEXANUCLEOTIDE REPEAT EXPANSION TOXICITY IN DROSOPHILA. Alzheimers Dement 2017. [DOI: 10.1016/j.jalz.2017.06.1361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Niccoli T, Cabecinha M, Tillmann A, Kerr F, Wong CT, Cardenes D, Vincent AJ, Bettedi L, Li L, Grönke S, Dols J, Partridge L. Increased Glucose Transport into Neurons Rescues Aβ Toxicity in Drosophila. Curr Biol 2016; 26:2550. [PMID: 27676294 PMCID: PMC5628945 DOI: 10.1016/j.cub.2016.09.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Niccoli T, Cabecinha M, Tillmann A, Kerr F, Wong CT, Cardenes D, Vincent AJ, Bettedi L, Li L, Grönke S, Dols J, Partridge L. Increased Glucose Transport into Neurons Rescues Aβ Toxicity in Drosophila. Curr Biol 2016; 26:2291-300. [PMID: 27524482 PMCID: PMC5026704 DOI: 10.1016/j.cub.2016.07.017] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 06/09/2016] [Accepted: 07/11/2016] [Indexed: 12/23/2022]
Abstract
Glucose hypometabolism is a prominent feature of the brains of patients with Alzheimer's disease (AD). Disease progression is associated with a reduction in glucose transporters in both neurons and endothelial cells of the blood-brain barrier. However, whether increasing glucose transport into either of these cell types offers therapeutic potential remains unknown. Using an adult-onset Drosophila model of Aβ (amyloid beta) toxicity, we show that genetic overexpression of a glucose transporter, specifically in neurons, rescues lifespan, behavioral phenotypes, and neuronal morphology. This amelioration of Aβ toxicity is associated with a reduction in the protein levels of the unfolded protein response (UPR) negative master regulator Grp78 and an increase in the UPR. We further demonstrate that genetic downregulation of Grp78 activity also protects against Aβ toxicity, confirming a causal effect of its alteration on AD-related pathology. Metformin, a drug that stimulates glucose uptake in cells, mimicked these effects, with a concomitant reduction in Grp78 levels and rescue of the shortened lifespan and climbing defects of Aβ-expressing flies. Our findings demonstrate a protective effect of increased neuronal uptake of glucose against Aβ toxicity and highlight Grp78 as a novel therapeutic target for the treatment of AD.
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Affiliation(s)
- Teresa Niccoli
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Melissa Cabecinha
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Anna Tillmann
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Fiona Kerr
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Chi T Wong
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Dalia Cardenes
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Alec J Vincent
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Lucia Bettedi
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Li Li
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Sebastian Grönke
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany
| | - Jacqueline Dols
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany
| | - Linda Partridge
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment (GEE), University College London, Darwin Building, Gower Street, London WC1E 6BT, UK; Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.
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17
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Mizielinska S, Grönke S, Niccoli T, Ridler CE, Clayton EL, Devoy A, Moens T, Norona FE, Woollacott IOC, Pietrzyk J, Cleverley K, Nicoll AJ, Pickering-Brown S, Dols J, Cabecinha M, Hendrich O, Fratta P, Fisher EMC, Partridge L, Isaacs AM. C9orf72 repeat expansions cause neurodegeneration in Drosophila through arginine-rich proteins. Science 2014; 345:1192-1194. [PMID: 25103406 DOI: 10.1126/science.1256800] [Citation(s) in RCA: 521] [Impact Index Per Article: 52.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
An expanded GGGGCC repeat in C9orf72 is the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. A fundamental question is whether toxicity is driven by the repeat RNA itself and/or by dipeptide repeat proteins generated by repeat-associated, non-ATG translation. To address this question, we developed in vitro and in vivo models to dissect repeat RNA and dipeptide repeat protein toxicity. Expression of pure repeats, but not stop codon-interrupted "RNA-only" repeats in Drosophila caused adult-onset neurodegeneration. Thus, expanded repeats promoted neurodegeneration through dipeptide repeat proteins. Expression of individual dipeptide repeat proteins with a non-GGGGCC RNA sequence revealed that both poly-(glycine-arginine) and poly-(proline-arginine) proteins caused neurodegeneration. These findings are consistent with a dual toxicity mechanism, whereby both arginine-rich proteins and repeat RNA contribute to C9orf72-mediated neurodegeneration.
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Affiliation(s)
- Sarah Mizielinska
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Sebastian Grönke
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, UCL, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Charlotte E Ridler
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Emma L Clayton
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Anny Devoy
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Thomas Moens
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, UCL, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Frances E Norona
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Ione O C Woollacott
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Julian Pietrzyk
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Karen Cleverley
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Andrew J Nicoll
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.,MRC Prion Unit, UCL Institute of Neurology, London WC1N 3BG, UK
| | - Stuart Pickering-Brown
- Institute of Brain, Behaviour and Mental Health, Faculty of Human and Medical Sciences, University of Manchester, AV Hill Building, Oxford Road, Manchester, M13 9PT, UK
| | - Jacqueline Dols
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany
| | - Melissa Cabecinha
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, UCL, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Oliver Hendrich
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany
| | - Pietro Fratta
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.,MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Elizabeth M C Fisher
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.,MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, UCL, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
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18
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Alic N, Tullet JM, Niccoli T, Broughton S, Hoddinott MP, Slack C, Gems D, Partridge L. Cell-nonautonomous effects of dFOXO/DAF-16 in aging. Cell Rep 2014; 6:608-16. [PMID: 24508462 PMCID: PMC3969275 DOI: 10.1016/j.celrep.2014.01.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/16/2013] [Accepted: 01/14/2014] [Indexed: 11/27/2022] Open
Abstract
Drosophila melanogaster and Caenorhabditis elegans each carry a single representative of the Forkhead box O (FoxO) family of transcription factors, dFOXO and DAF-16, respectively. Both are required for lifespan extension by reduced insulin/Igf signaling, and their activation in key tissues can extend lifespan. Aging of these tissues may limit lifespan. Alternatively, FoxOs may promote longevity cell nonautonomously by signaling to themselves (FoxO to FoxO) or other factors (FoxO to other) in distal tissues. Here, we show that activation of dFOXO and DAF-16 in the gut/fat body does not require dfoxo/daf-16 elsewhere to extend lifespan. Rather, in Drosophila, activation of dFOXO in the gut/fat body or in neuroendocrine cells acts on other organs to promote healthy aging by signaling to other, as-yet-unidentified factors. Whereas FoxO-to-FoxO signaling appears to be required for metabolic homeostasis, our results pinpoint FoxO-to-other signaling as an important mechanism through which localized FoxO activity ameliorates aging. dfoxo/daf-16 is not required beyond gut/adipose tissue to counteract aging Neuroendcrine dFOXO extends lifespan independently of dfoxo in other cell types In contrast, gut/adipose dFOXO requires dfoxo in other tissues to alter metabolism
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Affiliation(s)
- Nazif Alic
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Jennifer M Tullet
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Susan Broughton
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Matthew P Hoddinott
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK; Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany
| | - Cathy Slack
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - David Gems
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK; Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.
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19
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Abstract
Age is the main risk factor for the prevalent diseases of developed countries: cancer, cardiovascular disease and neurodegeneration. The ageing process is deleterious for fitness, but can nonetheless evolve as a consequence of the declining force of natural selection at later ages, attributable to extrinsic hazards to survival: ageing can then occur as a side-effect of accumulation of mutations that lower fitness at later ages, or of natural selection in favour of mutations that increase fitness of the young but at the cost of a higher subsequent rate of ageing. Once thought of as an inexorable, complex and lineage-specific process of accumulation of damage, ageing has turned out to be influenced by mechanisms that show strong evolutionary conservation. Lowered activity of the nutrient-sensing insulin/insulin-like growth factor/Target of Rapamycin signalling network can extend healthy lifespan in yeast, multicellular invertebrates, mice and, possibly, humans. Mitochondrial activity can also promote ageing, while genome maintenance and autophagy can protect against it. We discuss the relationship between evolutionarily conserved mechanisms of ageing and disease, and the associated scientific challenges and opportunities.
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Affiliation(s)
- Teresa Niccoli
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower St, London WC1E 6BT, UK
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20
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Dahlgaard K, Raposo AASF, Niccoli T, St Johnston D. Capu and Spire assemble a cytoplasmic actin mesh that maintains microtubule organization in the Drosophila oocyte. Dev Cell 2008; 13:539-53. [PMID: 17925229 PMCID: PMC2034408 DOI: 10.1016/j.devcel.2007.09.003] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 07/26/2007] [Accepted: 09/07/2007] [Indexed: 12/18/2022]
Abstract
Mutants in the actin nucleators Cappuccino and Spire disrupt the polarized microtubule network in the Drosophila oocyte that defines the anterior-posterior axis, suggesting that microtubule organization depends on actin. Here, we show that Cappuccino and Spire organize an isotropic mesh of actin filaments in the oocyte cytoplasm. capu and spire mutants lack this mesh, whereas overexpressed truncated Cappuccino stabilizes the mesh in the presence of Latrunculin A and partially rescues spire mutants. Spire overexpression cannot rescue capu mutants, but prevents actin mesh disassembly at stage 10B and blocks late cytoplasmic streaming. We also show that the actin mesh regulates microtubules indirectly, by inhibiting kinesin-dependent cytoplasmic flows. Thus, the Capu pathway controls alternative states of the oocyte cytoplasm: when active, it assembles an actin mesh that suppresses kinesin motility to maintain a polarized microtubule cytoskeleton. When inactive, unrestrained kinesin movement generates flows that wash microtubules to the cortex.
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Affiliation(s)
- Katja Dahlgaard
- The Wellcome Trust/Cancer Research UK Gurdon Institute and The Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
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21
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Niccoli T, Yamashita A, Nurse P, Yamamoto M. The p150-Glued Ssm4p regulates microtubular dynamics and nuclear movement in fission yeast. J Cell Sci 2004; 117:5543-56. [PMID: 15509865 DOI: 10.1242/jcs.01475] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
During vegetative growth of the fission yeast Schizosaccharomyces pombe, microtubules nucleate from multiple microtubule organising centres (MTOCs) close to the nucleus, polymerising until they reach the end of the cell and then shrinking back to the cell centre. In response to mating pheromone, S. pombe undergoes a morphological switch from a vegetative to a shmooing growth pattern. The switch in growth mode is paralleled by a switch in microtubular dynamics. Microtubules nucleate mostly from a single MTOC and pull on the ends of the cell to move the nucleus back and forth. This movement continues after cellular and nuclear fusion in the zygote and is important to ensure correct chromosome pairing, recombination and segregation during meiosis. Here we show that Ssm4p, a p150-Glued protein, is induced specifically in response to pheromone and is required for this nuclear movement. Ssm4p is associated with the cytoplasmic dynein complex and together with the CLIP-170 homologue Tip1p regulates dynein heavy chain localisation. We also show that Ssm4p collaborates with Tip1p in establishing the shmooing microtubular array.
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Affiliation(s)
- Teresa Niccoli
- Cancer Research UK, London Research Institute, Cell Cycle Laboratory, 44 Lincoln's Inn Fields, London, WC2A 3PX, UK
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22
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Abstract
Schizosaccharomyces pombe cells are rod-shaped and grow along a single axis from their two ends. Microtubules extend from the cell centre terminating at the cell ends. The ERM(ezrin/radixin/moesin)-like proteins Tea1p and Tea3p, and the Dyrk-like kinase Pom1p are cell end markers involved in the regulation of growth and microtubular dynamics at the cell ends. We have analysed the relative contribution of these three proteins to the determination of cell ends as sites both for cell growth and for microtubular termination. Pom1Delta, in combination with Tea1Delta or Tea3Delta, has the greatest difficulty in relocalizing actin to the cell ends following actin depolymerization and generates the most defective growth pattern. Tea1Delta, in combination with Pom1Delta or Tea3Delta, displays the highest number of microtubules bending round the cell ends. Tea1DeltaPom1Delta, which has the most defective growth pattern and microtubules, also displays the highest number of branched cells. We show that Tea1p, Tea3p and Pom1p all contribute, to different extents, to the determination of cell ends, as sites for both cell growth and microtubular termination. We also show that the fission yeast cell relies on both the positioning of landmarks and a properly organized microtubule cytoskeleton to direct cell growth.
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Affiliation(s)
- Teresa Niccoli
- Cancer Research UK London Research Institute, Cell Cycle Laboratory, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
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23
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Abstract
Eukaryotic cells are often polarized in their cytoplasmic structures, and this can be important for their function. The fission yeast Schizosaccharomyces pombe is a highly polarized cell that extends bipolarly along a single axis to generate a rod-shaped cell. It divides by medial fission to generate two equal-sized daughter cells that resume growth only at the old end. Once these cells have reached a particular length, they undergo NETO, new end take-off, whereby growth is activated at the other end to generate bipolarly extending cells. The activation and positioning of these growth zones are essential for maintaining growth in a straight line. Genetic analyses have identified many proteins involved in this process, like the cell end markers Tea1p and Pom1p and the kinases Orb2p/Shk1p/Pak1, Ssp1p, and Wee1p. Here, we describe tea3, a gene encoding a tea1-like protein with some similarities to ERM proteins. Tea3p is required for efficient NETO and for the proper placement of the septum. Like Pom1p, Tea3p localizes to cell ends, and its localization depends on microtubules and Tea1p. We propose that Tea3p is a novel cell end marker required specifically to activate polarized cell growth at the second end during NETO.
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Affiliation(s)
- Manuel Arellano
- Cancer Research UK London Research Institute, Cell Cycle Laboratory, P.O. Box 123, 44 Lincoln's Inn Fields, London WC2A 3PX, United Kingdom
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24
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Abstract
Schizosaccharomyces pombe cells have two polarised growth modes:an intrinsic vegetative growth mode, determined by an internal positioning mechanism and an extrinsic shmooing growth mode, activated by external pheromone. We have analysed the role of the cell end marker Tea1p, the CLIP170 like protein Tip1p, the kinesin like protein Tea2p and the Dyrk-like kinase Pom1p, during the switch between the two growth patterns, with the intention of studying the switch away from the vegetative growth mode. In vegetative growth these morphological factors are concentrated at cell ends, whereas during shmooing growth they are delocalised from the cell ends. In the absence of Tea1p, Tip1p and Tea2p, vegetative cells display microtubule and cell polarisation defects, but shmooing cells are indistinguishable from wild-type and shmoo more readily. These results suggest that Tea1p, Tip1p and Tea2p are not required for polarised growth during shmooing, but form part of the intrinsic vegetative growth mode that needs to be dismantled before cells can generate an extrinsic growth patterns. In contrast, Pom1p appears to have a role in the initial stages of the switch to the shmooing growth mode.
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Affiliation(s)
- Teresa Niccoli
- Cancer Research UK London Research Institute, Cell Cycle Laboratory, 44 Lincoln's Inn Fields, London, WC2A 3PX, UK.
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