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Zhang P, Catterson JH, Grönke S, Partridge L. Inhibition of S6K lowers age-related inflammation and increases lifespan through the endolysosomal system. Nat Aging 2024; 4:491-509. [PMID: 38413780 PMCID: PMC11031405 DOI: 10.1038/s43587-024-00578-3] [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] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 01/24/2024] [Indexed: 02/29/2024]
Abstract
Suppression of target of rapamycin complex 1 (TORC1) by rapamycin ameliorates aging in diverse species. S6 kinase (S6K) is an essential mediator, but the mechanisms involved are unclear. Here we show that activation of S6K specifically in Drosophila fat-body blocked extension of lifespan by rapamycin, induced accumulation of multilamellar lysosomes and blocked age-associated hyperactivation of the NF-κB-like immune deficiency (IMD) pathway, indicative of reduced inflammaging. Syntaxin 13 mediated the effects of TORC1-S6K signaling on lysosome morphology and inflammaging, suggesting they may be linked. Inflammaging depended on the IMD receptor regulatory isoform PGRP-LC, and repression of the IMD pathway from midlife extended lifespan. Age-related inflammaging was higher in females than in males and was not lowered in males by rapamycin treatment or lowered S6K. Rapamycin treatment also elevated Syntaxin 12/13 levels in mouse liver and prevented age-related increase in noncanonical NF-κB signaling, suggesting that the effect of TORC1 on inflammaging is conserved from flies to mammals.
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Affiliation(s)
- Pingze Zhang
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - James H Catterson
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
- Centre for Discovery Brain Sciences, UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | | | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK.
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2
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Colom-Cadena M, Toombs J, Simzer E, Holt K, McGeachan R, Tulloch J, Jackson RJ, Catterson JH, Spires-Jones MP, Rose J, Waybright L, Caggiano AO, King D, Gobbo F, Davies C, Hooley M, Dunnett S, Tempelaar R, Meftah S, Tzioras M, Hamby ME, Izzo NJ, Catalano SM, Durrant CS, Smith C, Dando O, Spires-Jones TL. Transmembrane protein 97 is a potential synaptic amyloid beta receptor in human Alzheimer's disease. Acta Neuropathol 2024; 147:32. [PMID: 38319380 PMCID: PMC10847197 DOI: 10.1007/s00401-023-02679-6] [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: 08/09/2023] [Revised: 12/24/2023] [Accepted: 12/24/2023] [Indexed: 02/07/2024]
Abstract
Synapse loss correlates with cognitive decline in Alzheimer's disease, and soluble oligomeric amyloid beta (Aβ) is implicated in synaptic dysfunction and loss. An important knowledge gap is the lack of understanding of how Aβ leads to synapse degeneration. In particular, there has been difficulty in determining whether there is a synaptic receptor that binds Aβ and mediates toxicity. While many candidates have been observed in model systems, their relevance to human AD brain remains unknown. This is in part due to methodological limitations preventing visualization of Aβ binding at individual synapses. To overcome this limitation, we combined two high resolution microscopy techniques: array tomography and Förster resonance energy transfer (FRET) to image over 1 million individual synaptic terminals in temporal cortex from AD (n = 11) and control cases (n = 9). Within presynapses and post-synaptic densities, oligomeric Aβ generates a FRET signal with transmembrane protein 97. Further, Aβ generates a FRET signal with cellular prion protein, and post-synaptic density 95 within post synapses. Transmembrane protein 97 is also present in a higher proportion of post synapses in Alzheimer's brain compared to controls. We inhibited Aβ/transmembrane protein 97 interaction in a mouse model of amyloidopathy by treating with the allosteric modulator CT1812. CT1812 drug concentration correlated negatively with synaptic FRET signal between transmembrane protein 97 and Aβ. In human-induced pluripotent stem cell derived neurons, transmembrane protein 97 is present in synapses and colocalizes with Aβ when neurons are challenged with human Alzheimer's brain homogenate. Transcriptional changes are induced by Aβ including changes in genes involved in neurodegeneration and neuroinflammation. CT1812 treatment of these neurons caused changes in gene sets involved in synaptic function. These data support a role for transmembrane protein 97 in the synaptic binding of Aβ in human Alzheimer's disease brain where it may mediate synaptotoxicity.
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Affiliation(s)
- Martí Colom-Cadena
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Jamie Toombs
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Elizabeth Simzer
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Kristjan Holt
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Robert McGeachan
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Jane Tulloch
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Rosemary J Jackson
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
- MassGeneral Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - James H Catterson
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Maxwell P Spires-Jones
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Jamie Rose
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | | | | | - Declan King
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Francesco Gobbo
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Caitlin Davies
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Monique Hooley
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Sophie Dunnett
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Robert Tempelaar
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Soraya Meftah
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Makis Tzioras
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
- Scottish Brain Sciences, Edinburgh, EH12 9DQ, UK
| | - Mary E Hamby
- Cognition Therapeutics Inc., Pittsburgh, PA, 15203, USA
| | | | | | - Claire S Durrant
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Colin Smith
- Centre for Clinical Brain Sciences and Sudden Death Brain Bank, University of Edinburgh, Edinburgh, EH16 4HB, UK
| | - Owen Dando
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Tara L Spires-Jones
- Centre for Discovery Brain Sciences and UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ, UK.
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3
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Taylor LW, Simzer EM, Pimblett C, Lacey-Solymar OTT, McGeachan RI, Meftah S, Rose JL, Spires-Jones MP, Holt K, Catterson JH, Koch H, Liaquat I, Clarke JH, Skidmore J, Smith C, Booker SA, Brennan PM, Spires-Jones TL, Durrant CS. p-tau Ser356 is associated with Alzheimer's disease pathology and is lowered in brain slice cultures using the NUAK inhibitor WZ4003. Acta Neuropathol 2024; 147:7. [PMID: 38175261 PMCID: PMC10766794 DOI: 10.1007/s00401-023-02667-w] [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: 08/29/2023] [Revised: 11/14/2023] [Accepted: 12/07/2023] [Indexed: 01/05/2024]
Abstract
Tau hyperphosphorylation and aggregation is a common feature of many dementia-causing neurodegenerative diseases. Tau can be phosphorylated at up to 85 different sites, and there is increasing interest in whether tau phosphorylation at specific epitopes, by specific kinases, plays an important role in disease progression. The AMP-activated protein kinase (AMPK)-related enzyme NUAK1 has been identified as a potential mediator of tau pathology, whereby NUAK1-mediated phosphorylation of tau at Ser356 prevents the degradation of tau by the proteasome, further exacerbating tau hyperphosphorylation and accumulation. This study provides a detailed characterisation of the association of p-tau Ser356 with progression of Alzheimer's disease pathology, identifying a Braak stage-dependent increase in p-tau Ser356 protein levels and an almost ubiquitous presence in neurofibrillary tangles. We also demonstrate, using sub-diffraction-limit resolution array tomography imaging, that p-tau Ser356 co-localises with synapses in AD postmortem brain tissue, increasing evidence that this form of tau may play important roles in AD progression. To assess the potential impacts of pharmacological NUAK inhibition in an ex vivo system that retains multiple cell types and brain-relevant neuronal architecture, we treated postnatal mouse organotypic brain slice cultures from wildtype or APP/PS1 littermates with the commercially available NUAK1/2 inhibitor WZ4003. Whilst there were no genotype-specific effects, we found that WZ4003 results in a culture-phase-dependent loss of total tau and p-tau Ser356, which corresponds with a reduction in neuronal and synaptic proteins. By contrast, application of WZ4003 to live human brain slice cultures results in a specific lowering of p-tau Ser356, alongside increased neuronal tubulin protein. This work identifies differential responses of postnatal mouse organotypic brain slice cultures and adult human brain slice cultures to NUAK1 inhibition that will be important to consider in future work developing tau-targeting therapeutics for human disease.
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Affiliation(s)
- Lewis W Taylor
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | - Elizabeth M Simzer
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | - Claire Pimblett
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | | | - Robert I McGeachan
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
- The Hospital for Small Animals, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh, UK
| | - Soraya Meftah
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | - Jamie L Rose
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | | | - Kristján Holt
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | - James H Catterson
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | - Henner Koch
- Department of Neurology, Epileptology, RWTH Aachen University Hospital, 52074, Aachen, Germany
| | - Imran Liaquat
- Department of Clinical Neuroscience, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, UK
| | - Jonathan H Clarke
- The ALBORADA Drug Discovery Institute, University of Cambridge, Island Research Building, Cambridge Biomedical Campus, Hills Road, Cambridge, UK
| | - John Skidmore
- The ALBORADA Drug Discovery Institute, University of Cambridge, Island Research Building, Cambridge Biomedical Campus, Hills Road, Cambridge, UK
| | - Colin Smith
- The Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Sam A Booker
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, The University of Edinburgh, Edinburgh, UK
| | - Paul M Brennan
- Department of Clinical Neuroscience, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, UK
- The Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
- Cancer Research UK Brain Tumour Centre of Excellence, CRUK Edinburgh Centre, The University of Edinburgh, Edinburgh, UK
| | - Tara L Spires-Jones
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
| | - Claire S Durrant
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK.
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK.
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4
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Catterson JH, Minkley L, Aspe S, Judd-Mole S, Moura S, Dyson MC, Rajasingam A, Woodling NS, Atilano ML, Ahmad M, Durrant CS, Spires-Jones TL, Partridge L. Protein retention in the endoplasmic reticulum rescues Aβ toxicity in Drosophila. Neurobiol Aging 2023; 132:154-174. [PMID: 37837732 PMCID: PMC10940166 DOI: 10.1016/j.neurobiolaging.2023.09.008] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 09/18/2023] [Accepted: 09/18/2023] [Indexed: 10/16/2023]
Abstract
Amyloid β (Aβ) accumulation is a hallmark of Alzheimer's disease. In adult Drosophila brains, human Aβ overexpression harms climbing and lifespan. It's uncertain whether Aβ is intrinsically toxic or activates downstream neurodegeneration pathways. Our study uncovers a novel protective role against Aβ toxicity: intra-endoplasmic reticulum (ER) protein accumulation with a focus on laminin and collagen subunits. Despite high Aβ, laminin B1 (LanB1) overexpression robustly counters toxicity, suggesting a potential Aβ resistance mechanism. Other laminin subunits and collagen IV also alleviate Aβ toxicity; combining them with LanB1 augments the effect. Imaging reveals ER retention of LanB1 without altering Aβ secretion. LanB1's rescue function operates independently of the IRE1α/XBP1 ER stress response. ER-targeted GFP overexpression also mitigates Aβ toxicity, highlighting broader ER protein retention advantages. Proof-of-principle tests in murine hippocampal slices using mouse Lamb1 demonstrate ER retention in transduced cells, indicating a conserved mechanism. Though ER protein retention generally harms, it could paradoxically counter neuronal Aβ toxicity, offering a new therapeutic avenue for Alzheimer's disease.
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Affiliation(s)
- James H Catterson
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK; Centre for Discovery Brain Sciences, UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, Scotland, UK
| | - Lucy Minkley
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Salomé Aspe
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Sebastian Judd-Mole
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Sofia Moura
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Miranda C Dyson
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Arjunan Rajasingam
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Nathaniel S Woodling
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Magda L Atilano
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Mumtaz Ahmad
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Claire S Durrant
- Centre for Discovery Brain Sciences, UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, Scotland, UK
| | - Tara L Spires-Jones
- Centre for Discovery Brain Sciences, UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, Scotland, UK
| | - Linda Partridge
- Institute of Healthy Ageing, Genetics, Evolution and Environment, 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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5
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Regan JC, Lu YX, Ureña E, Meilenbrock RL, Catterson JH, Kißler D, Fröhlich J, Funk E, Partridge L. Sexual identity of enterocytes regulates autophagy to determine intestinal health, lifespan and responses to rapamycin. Nat Aging 2022; 2:1145-1158. [PMID: 37118538 PMCID: PMC10154239 DOI: 10.1038/s43587-022-00308-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 10/04/2022] [Indexed: 04/30/2023]
Abstract
Pharmacological attenuation of mTOR presents a promising route for delay of age-related disease. Here we show that treatment of Drosophila with the mTOR inhibitor rapamycin extends lifespan in females, but not in males. Female-specific, age-related gut pathology is markedly slowed by rapamycin treatment, mediated by increased autophagy. Treatment increases enterocyte autophagy in females, via the H3/H4 histone-Bchs axis, whereas males show high basal levels of enterocyte autophagy that are not increased by rapamycin feeding. Enterocyte sexual identity, determined by transformerFemale expression, dictates sexually dimorphic cell size, H3/H4-Bchs expression, basal rates of autophagy, fecundity, intestinal homeostasis and lifespan extension in response to rapamycin. Dimorphism in autophagy is conserved in mice, where intestine, brown adipose tissue and muscle exhibit sex differences in autophagy and response to rapamycin. This study highlights tissue sex as a determining factor in the regulation of metabolic processes by mTOR and the efficacy of mTOR-targeted, anti-aging drug treatments.
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Affiliation(s)
- Jennifer C Regan
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK.
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, UK.
| | - Yu-Xuan Lu
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
| | - Enric Ureña
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
| | | | - James H Catterson
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Disna Kißler
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Jenny Fröhlich
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Emilie Funk
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Linda Partridge
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK.
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
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Catterson JH, Khericha M, Dyson MC, Vincent AJ, Callard R, Haveron SM, Rajasingam A, Ahmad M, Partridge L. Short-Term, Intermittent Fasting Induces Long-Lasting Gut Health and TOR-Independent Lifespan Extension. Curr Biol 2018; 28:1714-1724.e4. [PMID: 29779873 PMCID: PMC5988561 DOI: 10.1016/j.cub.2018.04.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [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: 07/28/2017] [Revised: 01/24/2018] [Accepted: 04/04/2018] [Indexed: 02/07/2023]
Abstract
Intermittent fasting (IF) can improve function and health during aging in laboratory model organisms, but the mechanisms at work await elucidation. We subjected fruit flies (Drosophila melanogaster) to varying degrees of IF and found that just one month of a 2-day fed:5-day fasted IF regime at the beginning of adulthood was sufficient to extend lifespan. This long-lasting, beneficial effect of early IF was not due to reduced fecundity. Starvation resistance and resistance to oxidative and xenobiotic stress were increased after IF. Early-life IF also led to higher lipid content in 60-day-old flies, a potential explanation for increased longevity. Guts of flies 40 days post-IF showed a significant reduction in age-related pathologies and improved gut barrier function. Improved gut health was also associated with reduced relative bacterial abundance. Early IF thus induced profound long-term changes. Pharmacological and genetic epistasis analysis showed that IF acted independently of the TOR pathway because rapamycin and IF acted additively to extend lifespan, and global expression of a constitutively active S6K did not attenuate the IF-induced lifespan extension. We conclude that short-term IF during early life can induce long-lasting beneficial effects, with robust increase in lifespan in a TOR-independent manner, probably at least in part by preserving gut health.
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Affiliation(s)
- James H Catterson
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Mobina Khericha
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Miranda C Dyson
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Alec J Vincent
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Rebecca Callard
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Steven M Haveron
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Arjunan Rajasingam
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Mumtaz Ahmad
- Institute of Healthy Ageing, Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Linda Partridge
- Institute of Healthy Ageing, Genetics, Evolution and Environment, 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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7
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Ivy JR, Drechsler M, Catterson JH, Bodmer R, Ocorr K, Paululat A, Hartley PS. Klf15 Is Critical for the Development and Differentiation of Drosophila Nephrocytes. PLoS One 2015; 10:e0134620. [PMID: 26301956 PMCID: PMC4547745 DOI: 10.1371/journal.pone.0134620] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [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: 03/02/2015] [Accepted: 07/11/2015] [Indexed: 12/20/2022] Open
Abstract
Insect nephrocytes are highly endocytic scavenger cells that represent the only invertebrate model for the study of human kidney podocytes. Despite their importance, nephrocyte development is largely uncharacterised. This work tested whether the insect ortholog of mammalian Kidney Krüppel-Like Factor (Klf15), a transcription factor required for mammalian podocyte differentiation, was required for insect nephrocyte development. It was found that expression of Drosophila Klf15 (dKlf15, previously known as Bteb2) was restricted to the only two nephrocyte populations in Drosophila, the garland cells and pericardial nephrocytes. Loss of dKlf15 function led to attrition of both nephrocyte populations and sensitised larvae to the xenotoxin silver nitrate. Although pericardial nephrocytes in dKlf15 loss of function mutants were specified during embryogenesis, they failed to express the slit diaphragm gene sticks and stones and did not form slit diaphragms. Conditional silencing of dKlf15 in adults led to reduced surface expression of the endocytic receptor Amnionless and loss of in vivo scavenger function. Over-expression of dKlf15 increased nephrocyte numbers and rescued age-dependent decline in nephrocyte function. The data place dKlf15 upstream of sns and Amnionless in a nephrocyte-restricted differentiation pathway and suggest dKlf15 expression is both necessary and sufficient to sustain nephrocyte differentiation. These findings explain the physiological relevance of dKlf15 in Drosophila and imply that the role of KLF15 in human podocytes is evolutionarily conserved.
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Affiliation(s)
- Jessica R. Ivy
- University of Edinburgh / British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Maik Drechsler
- Department of Zoology & Developmental Biology, University of Osnabrück, Barbarastr. 11, D-49069 Osnabrück, Germany
| | - James H. Catterson
- University of Edinburgh / British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Rolf Bodmer
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Karen Ocorr
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Achim Paululat
- Department of Zoology & Developmental Biology, University of Osnabrück, Barbarastr. 11, D-49069 Osnabrück, Germany
| | - Paul S. Hartley
- Department of Life and Environmental Science, University of Bournemouth, Talbot Campus, Poole, Dorset BH12 5BB, United Kingdom
- * E-mail:
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8
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Catterson JH, Heck MMS, Hartley PS. Fermitins, the orthologs of mammalian Kindlins, regulate the development of a functional cardiac syncytium in Drosophila melanogaster. PLoS One 2013; 8:e62958. [PMID: 23690969 PMCID: PMC3655056 DOI: 10.1371/journal.pone.0062958] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [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: 11/06/2012] [Accepted: 03/26/2013] [Indexed: 11/18/2022] Open
Abstract
The vertebrate Kindlins are an evolutionarily conserved family of proteins critical for integrin signalling and cell adhesion. Kindlin-2 (KIND2) is associated with intercalated discs in mice, suggesting a role in cardiac syncytium development; however, deficiency of Kind2 leads to embryonic lethality. Morpholino knock-down of Kind2 in zebrafish has a pleiotropic effect on development that includes the heart. It therefore remains unclear whether cardiomyocyte Kind2 expression is required for cardiomyocyte junction formation and the development of normal cardiac function. To address this question, the expression of Fermitin 1 and Fermitin 2 (Fit1, Fit2), the two Drosophila orthologs of Kind2, was silenced in Drosophila cardiomyocytes. Heart development was assessed in adult flies by immunological methods and videomicroscopy. Silencing both Fit1 and Fit2 led to a severe cardiomyopathy characterised by the failure of cardiomyocytes to develop as a functional syncytium and loss of synchrony between cardiomyocytes. A null allele of Fit1 was generated but this had no impact on the heart. Similarly, the silencing of Fit2 failed to affect heart function. In contrast, the silencing of Fit2 in the cardiomyocytes of Fit1 null flies disrupted syncytium development, leading to severe cardiomyopathy. The data definitively demonstrate a role for Fermitins in the development of a functional cardiac syncytium in Drosophila. The findings also show that the Fermitins can functionally compensate for each other in order to control syncytium development. These findings support the concept that abnormalities in cardiomyocyte KIND2 expression or function may contribute to cardiomyopathies in humans.
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Affiliation(s)
- James H. Catterson
- The University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, Midlothian, United Kingdom
| | - Margarete M. S. Heck
- The University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, Midlothian, United Kingdom
| | - Paul S. Hartley
- The University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, Midlothian, United Kingdom
- * E-mail:
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9
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Abstract
BACKGROUND Most physiologic processes exhibit diurnal fluctuations controlled by the circadian regulation of sleep-wake behavior and feeding cycles. In addition, many cell types express endogenous circadian rhythms that affect cell-specific processes. Independent reports support the hypothesis that thrombopoietin (TPO) is under circadian control. OBJECTIVES The current study tested the hypothesis that CLOCK, a circadian transcription factor, may regulate Thpo, the gene encoding TPO. METHODS Circadian gene expression patterns were analyzed in mice and in human cell lines, Small interfering RNA was used to knock down CLOCK expression in cell lines, and gene expression was also examined in Clock(Δ19/Δ19) mutant mice. RESULTS It was found that there was a diurnal rhythm in the expression of Thpoin vivo in mice, and that this was associated with concomitant rhythms of protein abundance. Thpo was rhythmically expressed in human cell lines, consistent with the gene being directly or indirectly regulated by the circadian clock. Silencing of CLOCK in the Huh7 human hepatoma cell line led to a significant reduction in the rhythmicity of Thpo expression. The expression of Mpl in murine marrow also displayed diurnal rhythmicity in vivo. In Clock(Δ19/Δ19) mutant mice, Thpo and Mpl expression was disrupted and there was an increase in the number of mature megakaryocytes, but no change in the ploidy distribution within the megakaryocyte population. CONCLUSIONS These findings establish that Clock regulates Thpo and Mpl expression in vivo, and demonstrate an important link between the body's circadian timing mechanisms and megakaryopoiesis.
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Affiliation(s)
- C J Tracey
- University/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
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10
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Dear JW, Simpson KJ, Nicolai MPJ, Catterson JH, Street J, Huizinga T, Craig DG, Dhaliwal K, Webb S, Bateman DN, Webb DJ. Cyclophilin A is a damage-associated molecular pattern molecule that mediates acetaminophen-induced liver injury. J Immunol 2011; 187:3347-52. [PMID: 21824865 DOI: 10.4049/jimmunol.1100165] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The immune system is alerted to cell death by molecules known as damage-associated molecular patterns (DAMPs). These molecules partly mediate acetaminophen-induced liver injury, an archetypal experimental model of sterile cell death and the commonest cause of acute liver failure in the western world. Cyclophilin A (CypA) is an intracellular protein that is proinflammatory when released by cells. We hypothesized that CypA is released from necrotic liver cells and acts as a DAMP to mediate acetaminophen-induced liver injury. Our data demonstrated that mice lacking CypA (Ppia(-/-)) were resistant to acetaminophen toxicity. Antagonism of the extracellular receptor for CypA (CD147) also reduced acetaminophen-induced liver injury. When injected into a wild-type mouse, necrotic liver from Ppia(-/-) mice induced less of an inflammatory response than did wild-type liver. Conversely, the host inflammatory response was increased when CypA was injected with necrotic liver. Antagonism of CD147 also reduced the inflammatory response to necrotic liver. In humans, urinary CypA concentration was significantly increased in patients with acetaminophen-induced liver injury. In summary, CypA is a DAMP that mediates acetaminophen poisoning. This mechanistic insight presents an opportunity for a new therapeutic approach to a disease that currently has inadequate treatment options.
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Affiliation(s)
- James W Dear
- University/British Heart Foundation Centre for Cardiovascular Science, Edinburgh University, Edinburgh, EH16 4TJ United Kingdom.
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