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Fabrizio P, Alcolei A, Solari F. Considering Caenorhabditis elegans Aging on a Temporal and Tissue Scale: The Case of Insulin/IGF-1 Signaling. Cells 2024; 13:288. [PMID: 38334680 PMCID: PMC10854721 DOI: 10.3390/cells13030288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 01/24/2024] [Accepted: 01/31/2024] [Indexed: 02/10/2024] Open
Abstract
The aging process is inherently complex, involving multiple mechanisms that interact at different biological scales. The nematode Caenorhabditis elegans is a simple model organism that has played a pivotal role in aging research following the discovery of mutations extending lifespan. Longevity pathways identified in C. elegans were subsequently found to be conserved and regulate lifespan in multiple species. These pathways intersect with fundamental hallmarks of aging that include nutrient sensing, epigenetic alterations, proteostasis loss, and mitochondrial dysfunction. Here we summarize recent data obtained in C. elegans highlighting the importance of studying aging at both the tissue and temporal scale. We then focus on the neuromuscular system to illustrate the kinetics of changes that take place with age. We describe recently developed tools that enabled the dissection of the contribution of the insulin/IGF-1 receptor ortholog DAF-2 to the regulation of worm mobility in specific tissues and at different ages. We also discuss guidelines and potential pitfalls in the use of these new tools. We further highlight the opportunities that they present, especially when combined with recent transcriptomic data, to address and resolve the inherent complexity of aging. Understanding how different aging processes interact within and between tissues at different life stages could ultimately suggest potential intervention points for age-related diseases.
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Affiliation(s)
- Paola Fabrizio
- Laboratoire de Biologie et Modélisation de la Cellule, Ecole Normale Supérieure de Lyon, CNRS UMR5239, INSERM 1210, University Claude Bernard Lyon 1, 69364 Lyon, France;
| | - Allan Alcolei
- INMG, MeLiS, CNRS UMR 5284, INSERM U1314, University Claude Bernard Lyon 1, 69008 Lyon, France;
| | - Florence Solari
- INMG, MeLiS, CNRS UMR 5284, INSERM U1314, University Claude Bernard Lyon 1, 69008 Lyon, France;
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2
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Smith HJ, Lanjuin A, Sharma A, Prabhakar A, Nowak E, Stine PG, Sehgal R, Stojanovski K, Towbin BD, Mair WB. Neuronal mTORC1 inhibition promotes longevity without suppressing anabolic growth and reproduction in C. elegans. PLoS Genet 2023; 19:e1010938. [PMID: 37721956 PMCID: PMC10538657 DOI: 10.1371/journal.pgen.1010938] [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: 01/17/2023] [Revised: 09/28/2023] [Accepted: 08/24/2023] [Indexed: 09/20/2023] Open
Abstract
mTORC1 (mechanistic target of rapamycin complex 1) is a metabolic sensor that promotes growth when nutrients are abundant. Ubiquitous inhibition of mTORC1 extends lifespan in multiple organisms but also disrupts several anabolic processes resulting in stunted growth, slowed development, reduced fertility, and disrupted metabolism. However, it is unclear if these pleiotropic effects of mTORC1 inhibition can be uncoupled from longevity. Here, we utilize the auxin-inducible degradation (AID) system to restrict mTORC1 inhibition to C. elegans neurons. We find that neuron-specific degradation of RAGA-1, an upstream activator of mTORC1, or LET-363, the ortholog of mammalian mTOR, is sufficient to extend lifespan in C. elegans. Unlike raga-1 loss of function genetic mutations or somatic AID of RAGA-1, neuronal AID of RAGA-1 robustly extends lifespan without impairing body size, developmental rate, brood size, or neuronal function. Moreover, while degradation of RAGA-1 in all somatic tissues alters the expression of thousands of genes, demonstrating the widespread effects of mTORC1 inhibition, degradation of RAGA-1 in neurons only results in around 200 differentially expressed genes with a specific enrichment in metabolism and stress response. Notably, our work demonstrates that targeting mTORC1 specifically in the nervous system in C. elegans uncouples longevity from growth and reproductive impairments, and that many canonical effects of low mTORC1 activity are not required to promote healthy aging. These data challenge previously held ideas about the mechanisms of mTORC1 lifespan extension and underscore the potential of promoting longevity by neuron-specific mTORC1 modulation.
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Affiliation(s)
- Hannah J. Smith
- Dept. Molecular Metabolism, Harvard TH Chan School of Public Health, Massachusetts, United States of America
| | - Anne Lanjuin
- Dept. Molecular Metabolism, Harvard TH Chan School of Public Health, Massachusetts, United States of America
| | - Arpit Sharma
- Dept. Molecular Metabolism, Harvard TH Chan School of Public Health, Massachusetts, United States of America
| | - Aditi Prabhakar
- Dept. Molecular Metabolism, Harvard TH Chan School of Public Health, Massachusetts, United States of America
| | - Ewelina Nowak
- Dept. Molecular Metabolism, Harvard TH Chan School of Public Health, Massachusetts, United States of America
| | - Peter G. Stine
- Dept. Molecular Metabolism, Harvard TH Chan School of Public Health, Massachusetts, United States of America
| | - Rohan Sehgal
- Dept. Molecular Metabolism, Harvard TH Chan School of Public Health, Massachusetts, United States of America
| | | | | | - William B. Mair
- Dept. Molecular Metabolism, Harvard TH Chan School of Public Health, Massachusetts, United States of America
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3
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Phanindhar K, Mishra RK. Auxin-inducible degron system: an efficient protein degradation tool to study protein function. Biotechniques 2023; 74:186-198. [PMID: 37191015 DOI: 10.2144/btn-2022-0108] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
Targeted protein degradation, with its rapid protein depletion kinetics, allows the measurement of acute changes in the cell. The auxin-inducible degron (AID) system, rapidly degrades AID-tagged proteins only in the presence of auxin. The AID system being inducible makes the study of essential genes and dynamic processes like cell differentiation, cell cycle and genome organization feasible. The AID degradation system has been adapted to yeast, protozoans, C. elegans, Drosophila, zebrafish, mouse and mammalian cell lines. Using the AID system, researchers have unveiled novel functions for essential proteins at developmental stages that were previously difficult to investigate due to early lethality. This comprehensive review discusses the development, advancements, applications and drawbacks of the AID system and compares it with other available protein degradation systems.
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Affiliation(s)
- Kundurthi Phanindhar
- CSIR-Centre for Cellular & Molecular Biology (CCMB), Uppal Road, Hyderabad, 500007, India
| | - Rakesh K Mishra
- CSIR-Centre for Cellular & Molecular Biology (CCMB), Uppal Road, Hyderabad, 500007, India
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India
- Tata Institute for Genetics & Society (TIGS), Bangalore, 560065, India
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Fragoso-Luna A, Romero-Bueno R, Eibl M, Ayuso C, Muñoz-Jiménez C, Benes V, Cases I, Askjaer P. Expanded FLP toolbox for spatiotemporal protein degradation and transcriptomic profiling in Caenorhabditis elegans. Genetics 2023; 223:iyac166. [PMID: 36321973 PMCID: PMC9836023 DOI: 10.1093/genetics/iyac166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/24/2022] [Indexed: 11/05/2022] Open
Abstract
Control of gene expression in specific tissues and/or at certain stages of development allows the study and manipulation of gene function with high precision. Site-specific genome recombination by the flippase (FLP) and cyclization recombination (Cre) enzymes has proved particularly relevant. Joint efforts of many research groups have led to the creation of efficient FLP and Cre drivers to regulate gene expression in a variety of tissues in Caenorhabditis elegans. Here, we extend this toolkit by the addition of FLP lines that drive recombination specifically in distal tip cells, the somatic gonad, coelomocytes, and the epithelial P lineage. In some cases, recombination-mediated gene knockouts do not completely deplete protein levels due to persistence of long-lived proteins. To overcome this, we developed a spatiotemporally regulated degradation system for green fluorescent fusion proteins based on FLP-mediated recombination. Using 2 stable nuclear pore proteins, MEL-28/ELYS and NPP-2/NUP85 as examples, we report the benefit of combining tissue-specific gene knockout and protein degradation to achieve complete protein depletion. We also demonstrate that FLP-mediated recombination can be utilized to identify transcriptomes in a C. elegans tissue of interest. We have adapted RNA polymerase DamID for the FLP toolbox and by focusing on a well-characterized tissue, the hypodermis, we show that the vast majority of genes identified by RNA polymerase DamID are known to be expressed in this tissue. These tools allow combining FLP activity for simultaneous gene inactivation and transcriptomic profiling, thus enabling the inquiry of gene function in various complex biological processes.
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Affiliation(s)
- Adrián Fragoso-Luna
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Raquel Romero-Bueno
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Michael Eibl
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Cristina Ayuso
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Celia Muñoz-Jiménez
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | | | - Ildefonso Cases
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Peter Askjaer
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
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Sepers JJ, Verstappen NHM, Vo AA, Ragle JM, Ruijtenberg S, Ward JD, Boxem M. The mIAA7 degron improves auxin-mediated degradation in Caenorhabditiselegans. G3 (BETHESDA, MD.) 2022; 12:jkac222. [PMID: 36029236 PMCID: PMC9526053 DOI: 10.1093/g3journal/jkac222] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/15/2022] [Indexed: 04/08/2023]
Abstract
Auxin-inducible degradation is a powerful tool for the targeted degradation of proteins with spatiotemporal control. One limitation of the auxin-inducible degradation system is that not all proteins are degraded efficiently. Here, we demonstrate that an alternative degron sequence, termed mIAA7, improves the efficiency of degradation in Caenorhabditiselegans, as previously reported in human cells. We tested the depletion of a series of proteins with various subcellular localizations in different tissue types and found that the use of the mIAA7 degron resulted in faster depletion kinetics for 5 out of 6 proteins tested. The exception was the nuclear protein HIS-72, which was depleted with similar efficiency as with the conventional AID* degron sequence. The mIAA7 degron also increased the leaky degradation for 2 of the tested proteins. To overcome this problem, we combined the mIAA7 degron with the C. elegans AID2 system, which resulted in complete protein depletion without detectable leaky degradation. Finally, we show that the degradation of ERM-1, a highly stable protein that is challenging to deplete, could be improved further by using multiple mIAA7 degrons. Taken together, the mIAA7 degron further increases the power and applicability of the auxin-inducible degradation system. To facilitate the generation of mIAA7-tagged proteins using CRISPR/Cas9 genome engineering, we generated a toolkit of plasmids for the generation of dsDNA repair templates by PCR.
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Affiliation(s)
- Jorian J Sepers
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Noud H M Verstappen
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - An A Vo
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Suzan Ruijtenberg
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Jordan D Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Mike Boxem
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
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6
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Elder CR, Pasquinelli AE. New Roles for MicroRNAs in Old Worms. FRONTIERS IN AGING 2022; 3:871226. [PMID: 35821862 PMCID: PMC9261348 DOI: 10.3389/fragi.2022.871226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/09/2022] [Indexed: 11/30/2022]
Abstract
The use of Caenorhabditis elegans as a model organism in aging research has been integral to our understanding of genes and pathways involved in this process. Several well-conserved signaling pathways that respond to insulin signaling, diet, and assaults to proteostasis have defined roles in controlling lifespan. New evidence shows that microRNAs (miRNAs) play prominent roles in regulating these pathways. In some cases, key aging-related genes have been established as direct targets of specific miRNAs. However, the precise functions of other miRNAs and their protein cofactors in promoting or antagonizing longevity still need to be determined. Here, we highlight recently uncovered roles of miRNAs in common aging pathways, as well as new techniques for the ongoing discovery of miRNA functions in aging C. elegans.
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Hills-Muckey K, Martinez MAQ, Stec N, Hebbar S, Saldanha J, Medwig-Kinney TN, Moore FEQ, Ivanova M, Morao A, Ward JD, Moss EG, Ercan S, Zinovyeva AY, Matus DQ, Hammell CM. An engineered, orthogonal auxin analog/AtTIR1(F79G) pairing improves both specificity and efficacy of the auxin degradation system in Caenorhabditis elegans. Genetics 2022; 220:iyab174. [PMID: 34739048 PMCID: PMC9097248 DOI: 10.1093/genetics/iyab174] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/17/2021] [Indexed: 02/06/2023] Open
Abstract
The auxin-inducible degradation system in C. elegans allows for spatial and temporal control of protein degradation via heterologous expression of a single Arabidopsis thaliana F-box protein, transport inhibitor response 1 (AtTIR1). In this system, exogenous auxin (Indole-3-acetic acid; IAA) enhances the ability of AtTIR1 to function as a substrate recognition component that adapts engineered degron-tagged proteins to the endogenous C. elegans E3 ubiquitin ligases complex [SKR-1/2-CUL-1-F-box (SCF)], targeting them for degradation by the proteosome. While this system has been employed to dissect the developmental functions of many C. elegans proteins, we have found that several auxin-inducible degron (AID)-tagged proteins are constitutively degraded by AtTIR1 in the absence of auxin, leading to undesired loss-of-function phenotypes. In this manuscript, we adapt an orthogonal auxin derivative/mutant AtTIR1 pair [C. elegans AID version 2 (C.e.AIDv2)] that transforms the specificity of allosteric regulation of TIR1 from IAA to one that is dependent on an auxin derivative harboring a bulky aryl group (5-Ph-IAA). We find that a mutant AtTIR1(F79G) allele that alters the ligand-binding interface of TIR1 dramatically reduces ligand-independent degradation of multiple AID*-tagged proteins. In addition to solving the ectopic degradation problem for some AID-targets, the addition of 5-Ph-IAA to culture media of animals expressing AtTIR1(F79G) leads to more penetrant loss-of-function phenotypes for AID*-tagged proteins than those elicited by the AtTIR1-IAA pairing at similar auxin analog concentrations. The improved specificity and efficacy afforded by the mutant AtTIR1(F79G) allele expand the utility of the AID system and broaden the number of proteins that can be effectively targeted with it.
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Affiliation(s)
| | - Michael A Q Martinez
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Natalia Stec
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Shilpa Hebbar
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Joanne Saldanha
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Taylor N Medwig-Kinney
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Frances E Q Moore
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Maria Ivanova
- Department of Molecular Biology, Rowan University, Stratford, NJ 08084, USA
| | - Ana Morao
- Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - J D Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Eric G Moss
- Department of Molecular Biology, Rowan University, Stratford, NJ 08084, USA
| | - Sevinc Ercan
- Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Anna Y Zinovyeva
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
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Loose JA, Ghazi A. Auxin treatment increases lifespan in Caenorhabditis elegans. Biol Open 2021; 10:261795. [PMID: 34184729 PMCID: PMC8186727 DOI: 10.1242/bio.058703] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/08/2021] [Indexed: 12/13/2022] Open
Abstract
The auxin-inducible degradation system (AID) has proven to be a highly versatile technology for rapid, robust and reversible depletion of proteins in multiple model systems. In recent years, AID has been adapted into the nematode Caenorhabditis elegans as a tool for conditional protein knockdown. Numerous transgenic strains have been created that, upon auxin exposure, undergo protein inactivation in the worm germline or somatic tissues, both during development and in young adults. Since longevity assays often involve long-term gene- and protein-manipulation, the facility for spatiotemporally precise and extended protein removal makes AID a potentially highly valuable tool for aging biology. However, whether auxins themselves impact worm longevity has not been directly addressed. Here, we show that prolonged exposure to indole 3-acetic acid (IAA), the auxin used in worm AID studies, extends lifespan. We also report that two transgenic strains expressing Arabidopsis proteins that are key components of the AID platform are longer lived than wild-type animals. Together, our results highlight the necessity for exercising caution while utilizing AID for longevity studies and in interpreting the resulting data. This article has an associated First Person interview with the first author of the paper. Summary: We report that auxin and auxin-inducible protein degradation tools alter lifespan in C. elegans.
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Affiliation(s)
- Julia A Loose
- Department of Pediatrics, University of Pittsburgh School of Medicine, Rangos Research Center, Children's Hospital of Pittsburgh, 15224 PA, USA
| | - Arjumand Ghazi
- Department of Pediatrics, University of Pittsburgh School of Medicine, Rangos Research Center, Children's Hospital of Pittsburgh, 15224 PA, USA.,Departments of Developmental Biology and Cell Biology and Physiology, University of Pittsburgh School of Medicine, Rangos Research Center, Children's Hospital of Pittsburgh, 15224 PA, USA
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