1
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Wilinski D, Dus M. N 6-adenosine methylation controls the translation of insulin mRNA. Nat Struct Mol Biol 2023; 30:1260-1264. [PMID: 37488356 DOI: 10.1038/s41594-023-01048-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 06/26/2023] [Indexed: 07/26/2023]
Abstract
Control of insulin mRNA translation is crucial for energy homeostasis, but the mechanisms remain largely unknown. We discovered that insulin mRNAs across invertebrates, vertebrates and mammals feature the modified base N6-methyladenosine (m6A). In flies, this RNA modification enhances insulin mRNA translation by promoting the association of the transcript with polysomes. Depleting m6A in Drosophila melanogaster insulin 2 mRNA (dilp2) directly through specific 3' untranslated region (UTR) mutations, or indirectly by mutating the m6A writer Mettl3, decreases dilp2 protein production, leading to aberrant energy homeostasis and diabetic-like phenotypes. Together, our findings reveal adenosine mRNA methylation as a key regulator of insulin protein synthesis with notable implications for energy balance and metabolic disease.
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Affiliation(s)
- Daniel Wilinski
- Department of Molecular, Cellular, and Developmental Biology, The University of Michigan, Ann Arbor, MI, USA
| | - Monica Dus
- Department of Molecular, Cellular, and Developmental Biology, The University of Michigan, Ann Arbor, MI, USA.
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2
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Islam RA, Rallis C. Ribosomal Biogenesis and Heterogeneity in Development, Disease, and Aging. EPIGENOMES 2023; 7:17. [PMID: 37606454 PMCID: PMC10443367 DOI: 10.3390/epigenomes7030017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/23/2023] Open
Abstract
Although reported in the literature, ribosome heterogeneity is a phenomenon whose extent and implications in cell and organismal biology is not fully appreciated. This has been the case due to the lack of the appropriate techniques and approaches. Heterogeneity can arise from alternative use and differential content of protein and RNA constituents, as well as from post-transcriptional and post-translational modifications. In the few examples we have, it is apparent that ribosomal heterogeneity offers an additional level and potential for gene expression regulation and might be a way towards tuning metabolism, stress, and growth programs to external and internal stimuli and needs. Here, we introduce ribosome biogenesis and discuss ribosomal heterogeneity in various reported occasions. We conclude that a systematic approach in multiple organisms will be needed to delineate this biological phenomenon and its contributions to growth, aging, and disease. Finally, we discuss ribosome mutations and their roles in disease.
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Affiliation(s)
- Rowshan Ara Islam
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Charalampos Rallis
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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3
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Villalobos-Cantor S, Barrett RM, Condon AF, Arreola-Bustos A, Rodriguez KM, Cohen MS, Martin I. Rapid cell type-specific nascent proteome labeling in Drosophila. eLife 2023; 12:83545. [PMID: 37092974 PMCID: PMC10125018 DOI: 10.7554/elife.83545] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 04/09/2023] [Indexed: 04/25/2023] Open
Abstract
Controlled protein synthesis is required to regulate gene expression and is often carried out in a cell type-specific manner. Protein synthesis is commonly measured by labeling the nascent proteome with amino acid analogs or isotope-containing amino acids. These methods have been difficult to implement in vivo as they require lengthy amino acid replacement procedures. O-propargyl-puromycin (OPP) is a puromycin analog that incorporates into nascent polypeptide chains. Through its terminal alkyne, OPP can be conjugated to a fluorophore-azide for directly visualizing nascent protein synthesis, or to a biotin-azide for capture and identification of newly-synthesized proteins. To achieve cell type-specific OPP incorporation, we developed phenylacetyl-OPP (PhAc-OPP), a puromycin analog harboring an enzyme-labile blocking group that can be removed by penicillin G acylase (PGA). Here, we show that cell type-specific PGA expression in Drosophila can be used to achieve OPP labeling of newly-synthesized proteins in targeted cell populations within the brain. Following a brief 2 hr incubation of intact brains with PhAc-OPP, we observe robust imaging and affinity purification of OPP-labeled nascent proteins in PGA-targeted cell populations. We apply this method to show a pronounced age-related decline in neuronal protein synthesis in the fly brain, demonstrating the capability of PhAc-OPP to quantitatively capture in vivo protein synthesis states. This method, which we call POPPi (PGA-dependent OPP incorporation), should be applicable for rapidly visualizing protein synthesis and identifying nascent proteins synthesized under diverse physiological and pathological conditions with cellular specificity in vivo.
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Affiliation(s)
- Stefanny Villalobos-Cantor
- Jungers Center for Neurosciences, Department of Neurology, Oregon Health and Science University, Portland, United States
| | - Ruth M Barrett
- Jungers Center for Neurosciences, Department of Neurology, Oregon Health and Science University, Portland, United States
| | - Alec F Condon
- Jungers Center for Neurosciences, Department of Neurology, Oregon Health and Science University, Portland, United States
| | - Alicia Arreola-Bustos
- Jungers Center for Neurosciences, Department of Neurology, Oregon Health and Science University, Portland, United States
| | - Kelsie M Rodriguez
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, United States
| | - Michael S Cohen
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, United States
| | - Ian Martin
- Jungers Center for Neurosciences, Department of Neurology, Oregon Health and Science University, Portland, United States
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, United States
- Parkinson Center of Oregon, Oregon Health and Science University, Portland, United States
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4
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Debès C, Papadakis A, Grönke S, Karalay Ö, Tain LS, Mizi A, Nakamura S, Hahn O, Weigelt C, Josipovic N, Zirkel A, Brusius I, Sofiadis K, Lamprousi M, Lu YX, Huang W, Esmaillie R, Kubacki T, Späth MR, Schermer B, Benzing T, Müller RU, Antebi A, Partridge L, Papantonis A, Beyer A. Ageing-associated changes in transcriptional elongation influence longevity. Nature 2023; 616:814-821. [PMID: 37046086 PMCID: PMC10132977 DOI: 10.1038/s41586-023-05922-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 03/07/2023] [Indexed: 04/14/2023]
Abstract
Physiological homeostasis becomes compromised during ageing, as a result of impairment of cellular processes, including transcription and RNA splicing1-4. However, the molecular mechanisms leading to the loss of transcriptional fidelity are so far elusive, as are ways of preventing it. Here we profiled and analysed genome-wide, ageing-related changes in transcriptional processes across different organisms: nematodes, fruitflies, mice, rats and humans. The average transcriptional elongation speed (RNA polymerase II speed) increased with age in all five species. Along with these changes in elongation speed, we observed changes in splicing, including a reduction of unspliced transcripts and the formation of more circular RNAs. Two lifespan-extending interventions, dietary restriction and lowered insulin-IGF signalling, both reversed most of these ageing-related changes. Genetic variants in RNA polymerase II that reduced its speed in worms5 and flies6 increased their lifespan. Similarly, reducing the speed of RNA polymerase II by overexpressing histone components, to counter age-associated changes in nucleosome positioning, also extended lifespan in flies and the division potential of human cells. Our findings uncover fundamental molecular mechanisms underlying animal ageing and lifespan-extending interventions, and point to possible preventive measures.
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Affiliation(s)
- Cédric Debès
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Antonios Papadakis
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | | | - Özlem Karalay
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Luke S Tain
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Athanasia Mizi
- Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
| | - Shuhei Nakamura
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Oliver Hahn
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Carina Weigelt
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Natasa Josipovic
- Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Anne Zirkel
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Isabell Brusius
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Konstantinos Sofiadis
- Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Mantha Lamprousi
- Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
| | - Yu-Xuan Lu
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Wenming Huang
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Reza Esmaillie
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Torsten Kubacki
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Martin R Späth
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Bernhard Schermer
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Thomas Benzing
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Roman-Ulrich Müller
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Adam Antebi
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany.
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
| | - Linda Partridge
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany.
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, UCL, London, UK.
| | - Argyris Papantonis
- Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany.
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
| | - Andreas Beyer
- Cluster of Excellence on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
- Institute for Genetics, Faculty of Mathematics and Natural Sciences, University of Cologne, Cologne, Germany.
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5
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Baghdadi M, Nespital T, Mesaros A, Buschbaum S, Withers DJ, Grönke S, Partridge L. Reduced insulin signaling in neurons induces sex-specific health benefits. SCIENCE ADVANCES 2023; 9:eade8137. [PMID: 36812323 PMCID: PMC9946356 DOI: 10.1126/sciadv.ade8137] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Reduced activity of insulin/insulin-like growth factor signaling (IIS) extends health and life span in mammals. Loss of the insulin receptor substrate 1 (Irs1) gene increases survival in mice and causes tissue-specific changes in gene expression. However, the tissues underlying IIS-mediated longevity are currently unknown. Here, we measured survival and health span in mice lacking IRS1 specifically in liver, muscle, fat, and brain. Tissue-specific loss of IRS1 did not increase survival, suggesting that lack of IRS1 in more than one tissue is required for life-span extension. Loss of IRS1 in liver, muscle, and fat did not improve health. In contrast, loss of neuronal IRS1 increased energy expenditure, locomotion, and insulin sensitivity, specifically in old males. Neuronal loss of IRS1 also caused male-specific mitochondrial dysfunction, activation of Atf4, and metabolic adaptations consistent with an activated integrated stress response at old age. Thus, we identified a male-specific brain signature of aging in response to reduced IIS associated with improved health at old age.
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Affiliation(s)
| | - Tobias Nespital
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Andrea Mesaros
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Dominic J. Withers
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
- Medical Research Council London Institute of Medical Sciences, London, UK
| | | | - Linda Partridge
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
- Institute of Healthy Ageing and Genetics, Evolution and Environment, University College London, London, UK
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6
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Morshed SA, Ma R, Latif R, Davies TF. Mechanisms in Graves Eye Disease: Apoptosis as the End Point of Insulin-Like Growth Factor 1 Receptor Inhibition. Thyroid 2022; 32:429-439. [PMID: 34927457 PMCID: PMC9048181 DOI: 10.1089/thy.2021.0176] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Background: Graves' eye disease, also called Graves' orbitopathy (GO), is a potentially debilitating autoimmune disease associated with retro-orbital inflammation and tissue expansion, involving both fibroblasts and adipocytes, resulting in periorbital edema, worsening proptosis, and muscle dysfunction with diplopia and may ultimately threaten sight. Accumulating evidence has indicated that autoantibodies to the thyrotropin receptor (TSHR), which induce the hyperthyroidism of Graves' disease, also help mediate the pathogenesis of the eye disease in susceptible individuals through TSHR expression on retro-orbital cells. Since it has long been known that the effects of insulin-like growth factor 1 (IGF-1) and thyrotropin are additive, recent clinical trials with a human monoclonal IGF-1 receptor blocking antibody (teprotumumab; IGF-1R-B-monoclonal antibody [mAb]) have demonstrated its ability to induce significant reductions in proptosis, diplopia, and clinical activity scores in patients with GO. However, the molecular mechanisms by which such an antibody achieves this result is unclear. Methods: We have used Li-Cor In-Cell Western, Western blot, and immunohistochemistry to define levels of different proteins in mouse and human fibroblast cells. Proteomic array was also used to define pathway signaling molecules. Using CCK-8 and BrdU cell proliferation ELISA, we have analyzed proliferative response of these cells to different antibodies. Results: We now show that a stimulating TSHR antibody was able to induce phosphorylation of the IGF-1R and initiate both TSHR and IGF-1R signaling in mouse and human fibroblasts. IGF-1R-B-mAb (1H7) inhibited all major IGF-1R signaling cascades and also reduced TSHR signaling. This resulted in the antibody-induced suppression of autophagy as shown by inhibition of multiple autophagy-related proteins (Beclin1, LC3a, LC3b, p62, and ULK1) and the induction of cell death by apoptosis as evidenced by activation of cleaved caspase 3, FADD, and caspase 8. Furthermore, this IGF-1R-blocking mAb suppressed serum-induced perkin and pink mitophagic proteins. Conclusions: Our observations clearly indicated that stimulating TSHR antibodies were able to enhance IGF-1R activity and contribute to retro-orbital cellular proliferation and inflammation. In contrast, an IGF-1R-B-mAb was capable of suppressing IGF-1R signaling leading to retro-orbital fibroblast/adipocyte death through the cell-extrinsic pathway of apoptosis. This is likely the major mechanism involved in proptosis reduction in patients with Graves' eye disease treated by IGF-1R inhibition.
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Affiliation(s)
- Syed A. Morshed
- Thyroid Research Unit, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- James J. Peters VA Medical Center, New York, New York, USA
- Address correspondence to: Syed A. Morshed, MD, PhD, Thyroid Research Unit, Icahn School of Medicine at Mount Sinai, Box 1055, 1 Gustave L Levy Place, New York, NY 10029, USA
| | - Risheng Ma
- Thyroid Research Unit, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- James J. Peters VA Medical Center, New York, New York, USA
| | - Rauf Latif
- Thyroid Research Unit, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- James J. Peters VA Medical Center, New York, New York, USA
| | - Terry F. Davies
- Thyroid Research Unit, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- James J. Peters VA Medical Center, New York, New York, USA
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7
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Zhang WH, Koyuncu S, Vilchez D. Insights Into the Links Between Proteostasis and Aging From C. elegans. FRONTIERS IN AGING 2022; 3:854157. [PMID: 35821832 PMCID: PMC9261386 DOI: 10.3389/fragi.2022.854157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 02/22/2022] [Indexed: 04/20/2023]
Abstract
Protein homeostasis (proteostasis) is maintained by a tightly regulated and interconnected network of biological pathways, preventing the accumulation and aggregation of damaged or misfolded proteins. Thus, the proteostasis network is essential to ensure organism longevity and health, while proteostasis failure contributes to the development of aging and age-related diseases that involve protein aggregation. The model organism Caenorhabditis elegans has proved invaluable for the study of proteostasis in the context of aging, longevity and disease, with a number of pivotal discoveries attributable to the use of this organism. In this review, we discuss prominent findings from C. elegans across the many key aspects of the proteostasis network, within the context of aging and disease. These studies collectively highlight numerous promising therapeutic targets, which may 1 day facilitate the development of interventions to delay aging and prevent age-associated diseases.
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Affiliation(s)
- William Hongyu Zhang
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Seda Koyuncu
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Faculty of Medicine, University Hospital Cologne, Cologne, Germany
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8
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Tain LS, Sehlke R, Meilenbrock RL, Leech T, Paulitz J, Chokkalingam M, Nagaraj N, Grönke S, Fröhlich J, Atanassov I, Mann M, Beyer A, Partridge L. Tissue-specific modulation of gene expression in response to lowered insulin signalling in Drosophila. eLife 2021; 10:67275. [PMID: 33879316 PMCID: PMC8060030 DOI: 10.7554/elife.67275] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/18/2021] [Indexed: 01/15/2023] Open
Abstract
Reduced activity of the insulin/IGF signalling network increases health during ageing in multiple species. Diverse and tissue-specific mechanisms drive the health improvement. Here, we performed tissue-specific transcriptional and proteomic profiling of long-lived Drosophila dilp2-3,5 mutants, and identified tissue-specific regulation of >3600 transcripts and >3700 proteins. Most expression changes were regulated post-transcriptionally in the fat body, and only in mutants infected with the endosymbiotic bacteria, Wolbachia pipientis, which increases their lifespan. Bioinformatic analysis identified reduced co-translational ER targeting of secreted and membrane-associated proteins and increased DNA damage/repair response proteins. Accordingly, age-related DNA damage and genome instability were lower in fat body of the mutant, and overexpression of a minichromosome maintenance protein subunit extended lifespan. Proteins involved in carbohydrate metabolism showed altered expression in the mutant intestine, and gut-specific overexpression of a lysosomal mannosidase increased autophagy, gut homeostasis, and lifespan. These processes are candidates for combatting ageing-related decline in other organisms.
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Affiliation(s)
| | - Robert Sehlke
- Max-Planck Institute for Biology of Ageing, Cologne, Germany.,CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, Cologne, Germany
| | | | - Thomas Leech
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Jonathan Paulitz
- Max-Planck Institute for Biology of Ageing, Cologne, Germany.,CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, Cologne, Germany
| | - Manopriya Chokkalingam
- CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, Cologne, Germany
| | - Nagarjuna Nagaraj
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | | | - Jenny Fröhlich
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Ilian Atanassov
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Andreas Beyer
- CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, Cologne, Germany.,Center for Molecular Medicine (CMMC) & Cologne School for Computational Biology (CSCB), University of Cologne, Cologne, Germany
| | - Linda Partridge
- Max-Planck Institute for Biology of Ageing, Cologne, Germany.,Institute of Healthy Ageing, and GEE, UCL, London, United Kingdom
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9
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Derisbourg MJ, Wester LE, Baddi R, Denzel MS. Mutagenesis screen uncovers lifespan extension through integrated stress response inhibition without reduced mRNA translation. Nat Commun 2021; 12:1678. [PMID: 33723245 PMCID: PMC7960713 DOI: 10.1038/s41467-021-21743-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 01/29/2021] [Indexed: 12/12/2022] Open
Abstract
Protein homeostasis is modulated by stress response pathways and its deficiency is a hallmark of aging. The integrated stress response (ISR) is a conserved stress-signaling pathway that tunes mRNA translation via phosphorylation of the translation initiation factor eIF2. ISR activation and translation initiation are finely balanced by eIF2 kinases and by the eIF2 guanine nucleotide exchange factor eIF2B. However, the role of the ISR during aging remains poorly understood. Using a genomic mutagenesis screen for longevity in Caenorhabditis elegans, we define a role of eIF2 modulation in aging. By inhibiting the ISR, dominant mutations in eIF2B enhance protein homeostasis and increase lifespan. Consistently, full ISR inhibition using phosphorylation-defective eIF2α or pharmacological ISR inhibition prolong lifespan. Lifespan extension through impeding the ISR occurs without a reduction in overall protein synthesis. Instead, we observe changes in the translational efficiency of a subset of mRNAs, of which the putative kinase kin-35 is required for lifespan extension. Evidently, lifespan is limited by the ISR and its inhibition may provide an intervention in aging.
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Affiliation(s)
| | - Laura E Wester
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Ruth Baddi
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Martin S Denzel
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
- CECAD - Cluster of Excellence, University of Cologne, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
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10
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Nijhout HF, Kudla AM, Hazelwood CC. Genetic assimilation and accommodation: Models and mechanisms. Curr Top Dev Biol 2020; 141:337-369. [PMID: 33602492 DOI: 10.1016/bs.ctdb.2020.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Genetic assimilation and genetic accommodation are mechanisms by which novel phenotypes are produced and become established in a population. Novel characters may be fixed and canalized so they are insensitive to environmental variation, or can be plastic and adaptively responsive to environmental variation. In this review we explore the various theories that have been proposed to explain the developmental origin and evolution of novel phenotypes and the mechanisms by which canalization and phenotypic plasticity evolve. These theories and models range from conceptual to mathematical and have taken different views of how genes and environment contribute to the development and evolution of the properties of phenotypes. We will argue that a deeper and more nuanced understanding of genetic accommodation requires a recognition that phenotypes are not static entities but are dynamic system properties with no fixed deterministic relationship between genotype and phenotype. We suggest a mechanistic systems-view of development that allows one to incorporate both genes and environment in a common model, and that enables both quantitative analysis and visualization of the evolution of canalization and phenotypic plasticity.
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Affiliation(s)
| | - Anna M Kudla
- Department of Biology, Duke University, Durham, NC, United States
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11
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Meep, a Novel Regulator of Insulin Signaling, Supports Development and Insulin Sensitivity via Maintenance of Protein Homeostasis in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2020; 10:4399-4410. [PMID: 32998936 PMCID: PMC7718763 DOI: 10.1534/g3.120.401688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Insulin signaling is critical for developmental growth and adult homeostasis, yet the downstream regulators of this signaling pathway are not completely understood. Using the model organism Drosophila melanogaster, we took a genomic approach to identify novel mediators of insulin signaling. These studies led to the identification of Meep, encoded by the gene CG32335. Expression of this gene is both insulin receptor- and diet-dependent. We found that Meep was specifically required in the developing fat body to tolerate a high-sugar diet (HSD). Meep is not essential on a control diet, but when reared on an HSD, knockdown of meep causes hyperglycemia, reduced growth, developmental delay, pupal lethality, and reduced longevity. These phenotypes stem in part from Meep’s role in promoting insulin sensitivity and protein stability. This work suggests a critical role for protein homeostasis in development during overnutrition. Because Meep is conserved and obesity-associated in mammals, future studies on Meep may help to understand the role of proteostasis in insulin-resistant type 2 diabetes.
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12
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Lv B, Wang J, Zhuo J, Yang H, Yang S, Wang Z, Song Q. Transcriptome sequencing reveals the effects of cadmium toxicity on the cold tolerance of the wolf spider Pirata subpiraticus. CHEMOSPHERE 2020; 254:126802. [PMID: 32660694 DOI: 10.1016/j.chemosphere.2020.126802] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/12/2020] [Accepted: 04/12/2020] [Indexed: 06/11/2023]
Abstract
As the predominant predator of pests in rice fields, spiders have been exposed to cadmium (Cd) pollution for a long time. The livability of spiders during the overwintering period is closely related to population growth in spring, but the effects of Cd on spider's survival of cold hardness and the underlining mechanism remain unclear. In the present study, we found that some growth parameters (body length, width, mass and livability) in the wolf spider Pirata subpiraticus were altered distinctively under Cd stress. To investigate the effects of Cd toxicity on the spider at molecular levels, RNA-sequencing was performed on the spiderlings undergoing ambient temperature alterations. Transcriptome data showed that a total of 807 differentially expressed genes (DEGs) were yielded in the comparison. The obtained DEGs were mainly linked with metabolism-related process, including oxidoreductase activity and lipid transport, and 25 DEGs were associated with the reported cryoprotectants, including glycerol, arginine, cysteine, heat shock protein, glucose and mannose. Growth factors (insulin growth factor, platelet-derived growth factor and transforming growth factor) and cytochrome P450 encoding genes were dramatically expressed in the spider. Furthermore, transcriptional factors (TFs) family were characterized according to the transcriptomic profile, and ZBTB TFs were represented the most distinctive alterations in the characterized genes. Collectively, our study illustrated that Cd poses disadvantageous effects on the growth of P. subpiraticus at cold ambient temperature, and the spiders are capable of responding to the adverse Cd stress by expressing the genes involved in the metabolism of energy substances, cryoprotectants and immune-related components.
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Affiliation(s)
- Bo Lv
- College of Life Science, Hunan Normal University, Changsha, 410006, Hunan, China
| | - Juan Wang
- College of Life Science, Hunan Normal University, Changsha, 410006, Hunan, China
| | - Junzhe Zhuo
- College of Bioscience and Biotechnology, Hunan Agriculture University, Changsha, Hunan, 410128, China
| | - Huilin Yang
- College of Bioscience and Biotechnology, Hunan Agriculture University, Changsha, Hunan, 410128, China
| | - Sufang Yang
- College of Life Science, Hunan Normal University, Changsha, 410006, Hunan, China
| | - Zhi Wang
- College of Life Science, Hunan Normal University, Changsha, 410006, Hunan, China.
| | - Qisheng Song
- Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA
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13
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Dietary Amino Acids Impact LRRK2-Induced Neurodegeneration in Parkinson's Disease Models. J Neurosci 2020; 40:6234-6249. [PMID: 32605938 DOI: 10.1523/jneurosci.2809-19.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 05/02/2020] [Accepted: 06/19/2020] [Indexed: 02/03/2023] Open
Abstract
The G2019S mutation in leucine-rich repeat kinase 2 (LRRK2) is a common cause of Parkinson's disease (PD) and results in age-related dopamine neuron loss and locomotor dysfunction in Drosophila melanogaster through an aberrant increase in bulk neuronal protein synthesis. Under nonpathologic conditions, protein synthesis is tightly controlled by metabolic regulation. Whether nutritional and metabolic influences on protein synthesis can modulate the pathogenic effect of LRRK2 on protein synthesis and thereby impact neuronal loss is a key unresolved question. Here, we show that LRRK2 G2019S-induced neurodegeneration is critically dependent on dietary amino acid content in Drosophila studies with both sexes. Low dietary amino acid concentration prevents aberrant protein synthesis and blocks LRRK2 G2019S-mediated neurodegeneration in Drosophila and rat primary neurons. Unexpectedly, a moderately high-amino acid diet also blocks dopamine neuron loss and motor deficits in Drosophila through a separate mechanism involving stress-responsive activation of 5'-AMP-activated protein kinase (AMPK) and neuroprotective induction of autophagy, implicating the importance of protein homeostasis to neuronal viability. At the highest amino acid diet of the range tested, PD-related neurodegeneration occurs in an age-related manner, but is also observed in control strains, suggesting that it is independent of mutant LRRK2 expression. We propose that dietary influences on protein synthesis and autophagy are critical determinants of LRRK2 neurodegeneration, opening up possibilities for future therapeutic intervention.SIGNIFICANCE STATEMENT Parkinson's disease (PD) prevalence is projected to rise as populations continue to age, yet there are no current therapeutic approaches that delay or stop disease progression. A broad role for leucine-rich repeat kinase 2 (LRRK2) mutations in familial and idiopathic PD has emerged. Here, we show that dietary amino acids are important determinants of neurodegeneration in a Drosophila model of LRRK2 PD. Restricting all amino acids effectively suppresses dopaminergic neuron loss and locomotor deficits and is associated with reduced protein synthesis, while moderately high amino acids similarly attenuate these PD-related phenotypes through a stress-responsive induction of 5'-AMP-activated protein kinase and autophagy. These studies suggest that diet plays an important role in the development of PD-related phenotypes linked to LRRK2.
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14
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Funk MC, Zhou J, Boutros M. Ageing, metabolism and the intestine. EMBO Rep 2020; 21:e50047. [PMID: 32567155 PMCID: PMC7332987 DOI: 10.15252/embr.202050047] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 04/18/2020] [Accepted: 05/29/2020] [Indexed: 12/14/2022] Open
Abstract
The intestinal epithelium serves as a dynamic barrier to the environment and integrates a variety of signals, including those from metabolites, commensal microbiota, immune responses and stressors upon ageing. The intestine is constantly challenged and requires a high renewal rate to replace damaged cells in order to maintain its barrier function. Essential for its renewal capacity are intestinal stem cells, which constantly give rise to progenitor cells that differentiate into the multiple cell types present in the epithelium. Here, we review the current state of research of how metabolism and ageing control intestinal stem cell function and epithelial homeostasis. We focus on recent insights gained from model organisms that indicate how changes in metabolic signalling during ageing are a major driver for the loss of stem cell plasticity and epithelial homeostasis, ultimately affecting the resilience of an organism and limiting its lifespan. We compare findings made in mouse and Drosophila and discuss differences and commonalities in the underlying signalling pathways and mechanisms in the context of ageing.
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Affiliation(s)
- Maja C Funk
- Division Signaling and Functional Genomics, German Cancer Research Center (DKFZ), Heidelberg University, Heidelberg, Germany
| | - Jun Zhou
- Division Signaling and Functional Genomics, German Cancer Research Center (DKFZ), Heidelberg University, Heidelberg, Germany
| | - Michael Boutros
- Division Signaling and Functional Genomics, German Cancer Research Center (DKFZ), Heidelberg University, Heidelberg, Germany
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15
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Ng'oma E, Williams-Simon PA, Rahman A, King EG. Diverse biological processes coordinate the transcriptional response to nutritional changes in a Drosophila melanogaster multiparent population. BMC Genomics 2020; 21:84. [PMID: 31992183 PMCID: PMC6988245 DOI: 10.1186/s12864-020-6467-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/08/2020] [Indexed: 12/19/2022] Open
Abstract
Background Environmental variation in the amount of resources available to populations challenge individuals to optimize the allocation of those resources to key fitness functions. This coordination of resource allocation relative to resource availability is commonly attributed to key nutrient sensing gene pathways in laboratory model organisms, chiefly the insulin/TOR signaling pathway. However, the genetic basis of diet-induced variation in gene expression is less clear. Results To describe the natural genetic variation underlying nutrient-dependent differences, we used an outbred panel derived from a multiparental population, the Drosophila Synthetic Population Resource. We analyzed RNA sequence data from multiple female tissue samples dissected from flies reared in three nutritional conditions: high sugar (HS), dietary restriction (DR), and control (C) diets. A large proportion of genes in the experiment (19.6% or 2471 genes) were significantly differentially expressed for the effect of diet, and 7.8% (978 genes) for the effect of the interaction between diet and tissue type (LRT, Padj. < 0.05). Interestingly, we observed similar patterns of gene expression relative to the C diet, in the DR and HS treated flies, a response likely reflecting diet component ratios. Hierarchical clustering identified 21 robust gene modules showing intra-modularly similar patterns of expression across diets, all of which were highly significant for diet or diet-tissue interaction effects (FDR Padj. < 0.05). Gene set enrichment analysis for different diet-tissue combinations revealed a diverse set of pathways and gene ontology (GO) terms (two-sample t-test, FDR < 0.05). GO analysis on individual co-expressed modules likewise showed a large number of terms encompassing many cellular and nuclear processes (Fisher exact test, Padj. < 0.01). Although a handful of genes in the IIS/TOR pathway including Ilp5, Rheb, and Sirt2 showed significant elevation in expression, many key genes such as InR, chico, most insulin peptide genes, and the nutrient-sensing pathways were not observed. Conclusions Our results suggest that a more diverse network of pathways and gene networks mediate the diet response in our population. These results have important implications for future studies focusing on diet responses in natural populations.
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Affiliation(s)
- E Ng'oma
- University of Missouri, 401 Tucker Hall, Columbia, MO, 65211, USA.
| | | | - A Rahman
- University of Missouri, 401 Tucker Hall, Columbia, MO, 65211, USA
| | - E G King
- University of Missouri, 401 Tucker Hall, Columbia, MO, 65211, USA
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16
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Tain LS, Jain C, Nespital T, Froehlich J, Hinze Y, Grönke S, Partridge L. Longevity in response to lowered insulin signaling requires glycine N-methyltransferase-dependent spermidine production. Aging Cell 2020; 19:e13043. [PMID: 31721422 PMCID: PMC6974722 DOI: 10.1111/acel.13043] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/24/2019] [Accepted: 08/30/2019] [Indexed: 11/27/2022] Open
Abstract
Reduced insulin/IGF signaling (IIS) extends lifespan in multiple organisms. Different processes in different tissues mediate this lifespan extension, with a set of interplays that remain unclear. We here show that, in Drosophila, reduced IIS activity modulates methionine metabolism, through tissue-specific regulation of glycine N-methyltransferase (Gnmt), and that this regulation is required for full IIS-mediated longevity. Furthermore, fat body-specific expression of Gnmt was sufficient to extend lifespan. Targeted metabolomics showed that reducing IIS activity led to a Gnmt-dependent increase in spermidine levels. We also show that both spermidine treatment and reduced IIS activity are sufficient to extend the lifespan of Drosophila, but only in the presence of Gnmt. This extension of lifespan was associated with increased levels of autophagy. Finally, we found that increased expression of Gnmt occurs in the liver of liver-specific IRS1 KO mice and is thus an evolutionarily conserved response to reduced IIS. The discovery of Gnmt and spermidine as tissue-specific modulators of IIS-mediated longevity may aid in developing future therapeutic treatments to ameliorate aging and prevent disease.
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Affiliation(s)
- Luke S. Tain
- Max‐Planck Institute for Biology of AgeingCologneGermany
| | - Chirag Jain
- Max‐Planck Institute for Biology of AgeingCologneGermany
| | | | | | - Yvonne Hinze
- Max‐Planck Institute for Biology of AgeingCologneGermany
| | | | - Linda Partridge
- Max‐Planck Institute for Biology of AgeingCologneGermany
- Institute of Healthy Ageing, and GEEUCLLondonUK
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17
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Abstract
Despite tremendous progress in recent years, our understanding of the evolution of ageing is still incomplete. A dominant paradigm maintains that ageing evolves due to the competing energy demands of reproduction and somatic maintenance leading to slow accumulation of unrepaired cellular damage with age. However, the centrality of energy trade-offs in ageing has been increasingly challenged as studies in different organisms have uncoupled the trade-off between reproduction and longevity. An emerging theory is that ageing instead is caused by biological processes that are optimized for early-life function but become harmful when they continue to run-on unabated in late life. This idea builds on the realization that early-life regulation of gene expression can break down in late life because natural selection is too weak to optimize it. Empirical evidence increasingly supports the hypothesis that suboptimal gene expression in adulthood can result in physiological malfunction leading to organismal senescence. We argue that the current state of the art in the study of ageing contradicts the widely held view that energy trade-offs between growth, reproduction, and longevity are the universal underpinning of senescence. Future research should focus on understanding the relative contribution of energy and function trade-offs to the evolution and expression of ageing.
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Affiliation(s)
- Alexei A Maklakov
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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18
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Page MM, Schuster EF, Mudaliar M, Herzyk P, Withers DJ, Selman C. Common and unique transcriptional responses to dietary restriction and loss of insulin receptor substrate 1 (IRS1) in mice. Aging (Albany NY) 2019; 10:1027-1052. [PMID: 29779018 PMCID: PMC5990393 DOI: 10.18632/aging.101446] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/08/2018] [Indexed: 11/25/2022]
Abstract
Dietary restriction (DR) is the most widely studied non-genetic intervention capable of extending lifespan across multiple taxa. Modulation of genes, primarily within the insulin/insulin-like growth factor signalling (IIS) and the mechanistic target of rapamycin (mTOR) signalling pathways also act to extend lifespan in model organisms. For example, mice lacking insulin receptor substrate-1 (IRS1) are long-lived and protected against several age-associated pathologies. However, it remains unclear how these particular interventions act mechanistically to produce their beneficial effects. Here, we investigated transcriptional responses in wild-type and IRS1 null mice fed an ad libitum diet (WTAL and KOAL) or fed a 30% DR diet (WTDR or KODR). Using an RNAseq approach we noted a high correlation coefficient of differentially expressed genes existed within the same tissue across WTDR and KOAL mice and many metabolic features were shared between these mice. Overall, we report that significant overlap exists in the tissue-specific transcriptional response between long-lived DR mice and IRS1 null mice. However, there was evidence of disconnect between transcriptional signatures and certain phenotypic measures between KOAL and KODR, in that additive effects on body mass were observed but at the transcriptional level DR induced a unique set of genes in these already long-lived mice.
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Affiliation(s)
- Melissa M Page
- Institute des Sciences de la Vie, Faculty of Sciences, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Eugene F Schuster
- The Breast Cancer Now Toby Robins Research Centre The Institute of Cancer Research, London, UK
| | - Manikhandan Mudaliar
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Glasgow Molecular Pathology Node, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Present address: Cerevance, Cambridge Science Park, Cambridge, UK
| | - Pawel Herzyk
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Campus, Bearsden, UK.,Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, London, UK.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Colin Selman
- Glasgow Ageing Research Network (GARNER), Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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19
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Lian T, Wu Q, Hodge BA, Wilson KA, Yu G, Yang M. Drosophila Gut-A Nexus Between Dietary Restriction and Lifespan. Int J Mol Sci 2018; 19:ijms19123810. [PMID: 30501099 PMCID: PMC6320777 DOI: 10.3390/ijms19123810] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 02/06/2023] Open
Abstract
Aging is often defined as the accumulation of damage at the molecular and cellular levels which, over time, results in marked physiological impairments throughout the organism. Dietary restriction (DR) has been recognized as one of the strongest lifespan extending therapies observed in a wide array of organisms. Recent studies aimed at elucidating how DR promotes healthy aging have demonstrated a vital role of the digestive tract in mediating the beneficial effects of DR. Here, we review how dietary restriction influences gut metabolic homeostasis and immune function. Our discussion is focused on studies of the Drosophila digestive tract, where we describe in detail the potential mechanisms in which DR enhances maintenance of the intestinal epithelial barrier, up-regulates lipid metabolic processes, and improves the ability of the gut to deal with damage or stress. We also examine evidence of a tissue-tissue crosstalk between gut and neighboring organs including brain and fat body. Taken together, we argue that the Drosophila gut plays a critical role in DR-mediated lifespan extension.
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Affiliation(s)
- Ting Lian
- Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu 611130, China.
| | - Qi Wu
- Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu 611130, China.
| | - Brian A Hodge
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94947, USA.
| | - Kenneth A Wilson
- Buck Institute for Research on Aging, 8001 Redwood Blvd., Novato, CA 94947, USA.
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
| | - Guixiang Yu
- Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu 611130, China.
| | - Mingyao Yang
- Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu 611130, China.
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20
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Abstract
INTRODUCTION Exosomes, nanosized extracellular vesicles, are known to circulate through the blood stream to transfer molecular signals from tissue to tissue. METHODS To determine whether exosomes affect aging in animals, we primarily identified the changes in exosomal miRNA contents during the aging process. In exosomes from 12-month-old mice, mmu-miR-126-5p and mmu-miR-466c-5p levels were decreased and mmu-miR-184-3p and mmu-miR-200b-5p levels were increased significantly compared with those of 3-month-old mice. Their levels in exosomes were partially correlated with those in tissues: levels of only mmu-miR-126-5p and mmu-miR-466c-5p in lungs and/or liver were decreased, but those of mmu-miR-184-3p and mmu-miR-200b-5p in tissues did not coincide with those of exosomes. RESULTS AND DISCUSSION In the aged tissues injected with young exosomes isolated from serum, mmu-miR-126b-5p levels were reversed in the lungs and liver. Expression changes in aging-associated molecules in young exosome-injected mice were obvious: p16Ink4A, MTOR, and IGF1R were significantly downregulated in the lungs and/or liver of old mice. In addition, telomerase-related genes such as Men1, Mre11a, Tep1, Terf2, Tert, and Tnks were significantly upregulated in the liver of old mice after injection of young exosomes. CONCLUSION These results indicate that exosomes from young mice could reverse the expression pattern of aging-associated molecules in aged mice. Eventually, exosomes may be used as a novel approach for the treatment and diagnosis of aging animals.
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Affiliation(s)
- Bo-Ram Lee
- Companion Diagnostics and Medical Technology Research Group, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea,
| | - Jung-Hee Kim
- Companion Diagnostics and Medical Technology Research Group, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea,
| | - Eun-Sook Choi
- Companion Diagnostics and Medical Technology Research Group, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea,
- Global Center for Bio-Convergence Spin System (BicSPINS), Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea,
| | - Jung-Hoon Cho
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang 37666, Republic of Korea
| | - Eunjoo Kim
- Companion Diagnostics and Medical Technology Research Group, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea,
- Global Center for Bio-Convergence Spin System (BicSPINS), Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea,
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21
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A Complex Relationship between Immunity and Metabolism in Drosophila Diet-Induced Insulin Resistance. Mol Cell Biol 2017; 38:MCB.00259-17. [PMID: 29084810 DOI: 10.1128/mcb.00259-17] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 10/18/2017] [Indexed: 12/31/2022] Open
Abstract
Both systemic insulin resistance and tissue-specific insulin resistance have been described in Drosophila and are accompanied by many indicators of metabolic disease. The downstream mediators of insulin-resistant pathophysiology remain unclear. We analyzed insulin signaling in the fat body studying loss and gain of function. When expression of the sole Drosophila insulin receptor (InR) was reduced in larval fat bodies, animals exhibited developmental delay and reduced size in a diet-dependent manner. Fat body InR knockdown also led to reduced survival on high-sugar diets. To look downstream of InR at potential mediators of insulin resistance, transcriptome sequencing (RNA-seq) studies in insulin-resistant fat bodies revealed differential expression of genes, including those involved in innate immunity. Obesity-associated insulin resistance led to increased susceptibility of flies to infection, as in humans. Reduced innate immunity was dependent on fat body InR expression. The peptidoglycan recognition proteins (PGRPs) PGRP-SB2 and PGRP-SC2 were selected for further study based on differential expression studies. Downregulating PGRP-SB2 selectively in the fat body protected animals from the deleterious effects of overnutrition, whereas downregulating PGRP-SC2 produced InR-like phenotypes. These studies extend earlier work linking the immune and insulin signaling pathways and identify new targets of insulin signaling that could serve as potential drug targets to treat type 2 diabetes.
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22
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Tain LS, Sehlke R, Jain C, Chokkalingam M, Nagaraj N, Essers P, Rassner M, Grönke S, Froelich J, Dieterich C, Mann M, Alic N, Beyer A, Partridge L. A proteomic atlas of insulin signalling reveals tissue-specific mechanisms of longevity assurance. Mol Syst Biol 2017; 13:939. [PMID: 28916541 PMCID: PMC5615923 DOI: 10.15252/msb.20177663] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/15/2017] [Accepted: 08/16/2017] [Indexed: 12/20/2022] Open
Abstract
Lowered activity of the insulin/IGF signalling (IIS) network can ameliorate the effects of ageing in laboratory animals and, possibly, humans. Although transcriptome remodelling in long-lived IIS mutants has been extensively documented, the causal mechanisms contributing to extended lifespan, particularly in specific tissues, remain unclear. We have characterized the proteomes of four key insulin-sensitive tissues in a long-lived Drosophila IIS mutant and control, and detected 44% of the predicted proteome (6,085 proteins). Expression of ribosome-associated proteins in the fat body was reduced in the mutant, with a corresponding, tissue-specific reduction in translation. Expression of mitochondrial electron transport chain proteins in fat body was increased, leading to increased respiration, which was necessary for IIS-mediated lifespan extension, and alone sufficient to mediate it. Proteasomal subunits showed altered expression in IIS mutant gut, and gut-specific over-expression of the RPN6 proteasomal subunit, was sufficient to increase proteasomal activity and extend lifespan, whilst inhibition of proteasome activity abolished IIS-mediated longevity. Our study thus uncovered strikingly tissue-specific responses of cellular processes to lowered IIS acting in concert to ameliorate ageing.
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Affiliation(s)
- Luke S Tain
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Robert Sehlke
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
- CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, Cologne, Germany
| | - Chirag Jain
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Manopriya Chokkalingam
- CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, Cologne, Germany
| | - Nagarjuna Nagaraj
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Paul Essers
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Mark Rassner
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Jenny Froelich
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
| | - Christoph Dieterich
- Section of Bioinformatics and Systems Cardiology, Department of Internal Medicine III and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Nazif Alic
- Institute of Healthy Ageing, and GEE, UCL, London, UK
| | - Andreas Beyer
- CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Linda Partridge
- Max-Planck Institute for Biology of Ageing, Cologne, Germany
- Institute of Healthy Ageing, and GEE, UCL, London, UK
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