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Pires da Silva A, Kelleher R, Reynoldson L. Decoding lifespan secrets: the role of the gonad in Caenorhabditis elegans aging. FRONTIERS IN AGING 2024; 5:1380016. [PMID: 38605866 PMCID: PMC11008531 DOI: 10.3389/fragi.2024.1380016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 03/18/2024] [Indexed: 04/13/2024]
Abstract
The gonad has become a central organ for understanding aging in C. elegans, as removing the proliferating stem cells in the germline results in significant lifespan extension. Similarly, when starvation in late larval stages leads to the quiescence of germline stem cells the adult nematode enters reproductive diapause, associated with an extended lifespan. This review summarizes recent advancements in identifying the mechanisms behind gonad-mediated lifespan extension, including comparisons with other nematodes and the role of lipid signaling and transcriptional changes. Given that the gonad also mediates lifespan regulation in other invertebrates and vertebrates, elucidating the underlying mechanisms may help to gain new insights into the mechanisms and evolution of aging.
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Jofré DM, Hoffman DK, Cervino AS, Hahn GM, Grundy M, Yun S, Amrit FRG, Stolz DB, Godoy LF, Salvatore E, Rossi FA, Ghazi A, Cirio MC, Yanowitz JL, Hochbaum D. The CHARGE syndrome ortholog CHD-7 regulates TGF-β pathways in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2022; 119:e2109508119. [PMID: 35394881 PMCID: PMC9169646 DOI: 10.1073/pnas.2109508119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 02/24/2022] [Indexed: 11/18/2022] Open
Abstract
CHARGE syndrome is a complex developmental disorder caused by mutations in the chromodomain helicase DNA-binding protein-7 (CHD7) and characterized by retarded growth and malformations in the heart and nervous system. Despite the public health relevance of this disorder, relevant cellular pathways and targets of CHD7 that relate to disease pathology are still poorly understood. Here we report that chd-7, the nematode ortholog of Chd7, is required for dauer morphogenesis, lifespan determination, stress response, and body size determination. Consistent with our discoveries, we found chd-7 to be allelic to scd-3, a previously identified dauer suppressor from the DAF-7/ tumor growth factor-β (TGF-β) pathway. Epistatic analysis places CHD-7 at the level of the DAF-3/DAF-5 complex, but we found that CHD-7 also directly impacts the expression of multiple components of this pathway. Transcriptomic analysis revealed that chd-7 mutants fail to repress daf-9 for execution of the dauer program. In addition, CHD-7 regulates the DBL-1/BMP pathway components and shares roles in male tail development and cuticle synthesis. To explore a potential conserved function for chd-7 in vertebrates, we used Xenopus laevis embryos, an established model to study craniofacial development. Morpholino-mediated knockdown of Chd7 led to a reduction in col2a1 messenger RNA (mRNA) levels, a collagen whose expression depends on TGF-β signaling. Both embryonic lethality and craniofacial defects in Chd7-depleted tadpoles were partially rescued by overexpression of col2a1 mRNA. We suggest that Chd7 has conserved roles in regulation of the TGF-β signaling pathway and pathogenic Chd7 could lead to a defective extracellular matrix deposition.
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Affiliation(s)
- Diego M. Jofré
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1053 Buenos Aires, Argentina
| | | | - Ailen S. Cervino
- Instituto de Fisiología, Biología Molecular y Neurociencias, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1053 Buenos Aires, Argentina
| | - Gabriella M. Hahn
- Interdisciplinary Biomedical Graduate Program, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | | | - Sijung Yun
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20814
| | - Francis R. G. Amrit
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | - Donna B. Stolz
- Center for Biologic Imaging, University of Pittsburgh Medical School, Pittsburgh, PA 15213
| | - Luciana F. Godoy
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1053 Buenos Aires, Argentina
| | - Esteban Salvatore
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1053 Buenos Aires, Argentina
| | - Fabiana A. Rossi
- Instituto de Investigaciones en Medicina Traslacional, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Universidad Austral, B1630 Pilar, Argentina
| | - Arjumand Ghazi
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
- Department of Cell Biology & Physiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | - M. Cecilia Cirio
- Instituto de Fisiología, Biología Molecular y Neurociencias, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1053 Buenos Aires, Argentina
| | - Judith L. Yanowitz
- Magee-Womens Research Institute, Pittsburgh, PA 15213
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA 15213
- Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA 15213
| | - Daniel Hochbaum
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1053 Buenos Aires, Argentina
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Mallick S, Mishra N, Barik BK, Negi VD. Salmonella Typhimurium fepB negatively regulates C. elegans behavioral plasticity. J Infect 2022; 84:518-530. [PMID: 34990707 DOI: 10.1016/j.jinf.2021.12.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 10/19/2022]
Abstract
OBJECTIVES Dauer is an alternative developmental stage of Caenorhabditis elegans (C. elegans) that gives survival benefits under unfavorable environmental conditions. Our study aims to decipher C. elegans dauer larvae development upon Salmonella Typhimurium infection and how the bacterial gene regulating the worm's behavioural plasticity for better survival. METHODS Age-synchronized L4 C. elegans worms were infected with Salmonella Typhimurium 14028s (WT-STM) strain and mutant strains to check the dauer larvae development using 1% SDS. Besides, bacterial load in animals' gut, pharyngeal pumping rate and viability were checked. Worm's immune genes (e.g., ilys-3, lys-7, pmk-1, abf-2, clec-60) and dauer regulatory genes (e.g., daf-7, daf-11, daf-12, daf-16, daf-3) were checked by performing qRT-PCR under infection conditions. RESULTS We found that deletion of the fepB gene in S. Typhimurium strain became less pathogenic with reduced flagellar motility and biofilm-forming ability. Besides, there was decreased bacterial burden in the worm's gut with no damage to their pharynx. The fepB mutant strain was also able to enhance the immune responses for better survival of worms. Infection with mutant strain could activate dauer signaling via the TGF-β pathway leading to a significant increase in dauer formation than WT-STM infection. CONCLUSION Our study indicated that the bacteria act as a food source for the growth of C. elegans and development and can act as a signal that might be playing an essential role in regulating the host physiology for their survival. Such a study can help us in understanding the complex host-pathogen interaction benefiting pathogen in host dissemination.
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Affiliation(s)
- Swarupa Mallick
- Laboratory of Infection Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
| | - Neha Mishra
- Laboratory of Infection Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
| | - Bedanta Kumar Barik
- Laboratory of Infection Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
| | - Vidya Devi Negi
- Laboratory of Infection Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
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Biglou SG, Bendena WG, Chin-Sang I. An overview of the insulin signaling pathway in model organisms Drosophila melanogaster and Caenorhabditis elegans. Peptides 2021; 145:170640. [PMID: 34450203 DOI: 10.1016/j.peptides.2021.170640] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 08/01/2021] [Accepted: 08/20/2021] [Indexed: 12/12/2022]
Abstract
The insulin/insulin-like growth factor signaling pathway is an evolutionary conserved pathway across metazoans and is required for development, metabolism and behavior. This pathway is associated with various human metabolic disorders and cancers. Thus, model organisms including Drosophila melanogaster and Caenorhabditis elegans provide excellent opportunities to examine the structure and function of this pathway and its influence on cellular metabolism and proliferation. In this review, we will provide an overview of human insulin and the human insulin signaling pathway and explore the recent discoveries in model organisms Drosophila melanogaster and Caenorhabditis elegans. Our review will provide information regarding the various insulin-like peptides in model organisms as well as the conserved functions of insulin signaling pathways. Further investigation of the insulin signaling pathway in model organisms could provide a promising opportunity to develop novel therapies for various metabolic disorders and insulin-mediated cancers.
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Affiliation(s)
- Sanaz G Biglou
- Department of Biology, Queen's University Kingston, ON, K7L3N6, Canada
| | - William G Bendena
- Department of Biology, Queen's University Kingston, ON, K7L3N6, Canada; Centre for Neuroscience, Queen's University, Kingston, ON, K7L3N6, Canada.
| | - Ian Chin-Sang
- Department of Biology, Queen's University Kingston, ON, K7L3N6, Canada
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Dubois C, Gupta S, Mugler A, Félix MA. Temporally regulated cell migration is sensitive to variation in body size. Development 2021; 148:dev196949. [PMID: 33593818 PMCID: PMC10683003 DOI: 10.1242/dev.196949] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/14/2021] [Indexed: 12/15/2022]
Abstract
Few studies have measured the robustness to perturbations of the final position of a long-range migrating cell. In the nematode Caenorhabditis elegans, the QR neuroblast migrates anteriorly, while undergoing three division rounds. We study the final position of two of its great-granddaughters, the end of migration of which was previously shown to depend on a timing mechanism. We find that the variance in their final position is similar to that of other long-range migrating neurons. As expected from the timing mechanism, the position of QR descendants depends on body size, which we varied by changing maternal age or using body size mutants. Using a mathematical model, we show that body size variation is partially compensated for. Applying environmental perturbations, we find that the variance in final position increased following starvation at hatching. The mean position is displaced upon a temperature shift. Finally, highly significant variation was found among C. elegans wild isolates. Overall, this study reveals that the final position of these neurons is quite robust to stochastic variation, shows some sensitivity to body size and to external perturbations, and varies in the species.This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Clément Dubois
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, 75005 Paris, France
| | - Shivam Gupta
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, USA
| | - Andrew Mugler
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, USA
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Marie-Anne Félix
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, 75005 Paris, France
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Developmental plasticity and the response to nutrient stress in Caenorhabditis elegans. Dev Biol 2021; 475:265-276. [PMID: 33549550 DOI: 10.1016/j.ydbio.2021.01.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/24/2020] [Accepted: 01/29/2021] [Indexed: 11/23/2022]
Abstract
Developmental plasticity refers the ability of an organism to adapt to various environmental stressors, one of which is nutritional stress. Caenorhabditis elegans require various nutrients to successfully progress through all the larval stages to become a reproductive adult. If nutritional criteria are not satisfied, development can slow or completely arrest. In poor growth conditions, the animal can enter various diapause stages, depending on its developmental progress. In C. elegans, there are three well-characterized diapauses: the L1 arrest, the dauer diapause, and adult reproductive diapause, each associated with drastic changes in metabolism and germline development. At the centre of these changes is AMP-activated protein kinase (AMPK). AMPK is a metabolic regulator that maintains energy homeostasis, particularly during times of nutrient stress. Without AMPK, metabolism is disrupted during dauer, leading to the rapid consumption of lipid stores as well as misregulation of metabolic enzymes, leading to reduced survival. During the L1 arrest and dauer diapause, AMPK is responsible for ensuring germline quiescence by modifying the germline chromatin landscape to maintain germ cell integrity until conditions improve. Similar to classic hormonal signalling, small RNAs also play a critical role in regulating development and behaviour in a cell non-autonomous fashion. Thus, during the challenges associated with developmental plasticity, AMPK summons an army of signalling pathways to work collectively to preserve reproductive fitness during these periods of unprecedented uncertainty.
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Mata-Cabana A, Pérez-Nieto C, Olmedo M. Nutritional control of postembryonic development progression and arrest in Caenorhabditis elegans. ADVANCES IN GENETICS 2020; 107:33-87. [PMID: 33641748 DOI: 10.1016/bs.adgen.2020.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Developmental programs are under strict genetic control that favors robustness of the process. In order to guarantee the same outcome in different environmental situations, development is modulated by input pathways, which inform about external conditions. In the nematode Caenorhabditis elegans, the process of postembryonic development involves a series of stereotypic cell divisions, the progression of which is controlled by the nutritional status of the animal. C. elegans can arrest development at different larval stages, leading to cell arrest of the relevant divisions of the stage. This means that studying the nutritional control of development in C. elegans we can learn about the mechanisms controlling cell division in an in vivo model. In this work, we reviewed the current knowledge about the nutrient sensing pathways that control the progression or arrest of development in response to nutrient availability, with a special focus on the arrest at the L1 stage.
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Affiliation(s)
- Alejandro Mata-Cabana
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avd. Reina Mercedes, Sevilla, Spain
| | - Carmen Pérez-Nieto
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avd. Reina Mercedes, Sevilla, Spain
| | - María Olmedo
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avd. Reina Mercedes, Sevilla, Spain.
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8
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Baugh LR, Hu PJ. Starvation Responses Throughout the Caenorhabditiselegans Life Cycle. Genetics 2020; 216:837-878. [PMID: 33268389 PMCID: PMC7768255 DOI: 10.1534/genetics.120.303565] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/17/2020] [Indexed: 02/07/2023] Open
Abstract
Caenorhabditis elegans survives on ephemeral food sources in the wild, and the species has a variety of adaptive responses to starvation. These features of its life history make the worm a powerful model for studying developmental, behavioral, and metabolic starvation responses. Starvation resistance is fundamental to life in the wild, and it is relevant to aging and common diseases such as cancer and diabetes. Worms respond to acute starvation at different times in the life cycle by arresting development and altering gene expression and metabolism. They also anticipate starvation during early larval development, engaging an alternative developmental program resulting in dauer diapause. By arresting development, these responses postpone growth and reproduction until feeding resumes. A common set of signaling pathways mediates systemic regulation of development in each context but with important distinctions. Several aspects of behavior, including feeding, foraging, taxis, egg laying, sleep, and associative learning, are also affected by starvation. A variety of conserved signaling, gene regulatory, and metabolic mechanisms support adaptation to starvation. Early life starvation can have persistent effects on adults and their descendants. With its short generation time, C. elegans is an ideal model for studying maternal provisioning, transgenerational epigenetic inheritance, and developmental origins of adult health and disease in humans. This review provides a comprehensive overview of starvation responses throughout the C. elegans life cycle.
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Affiliation(s)
- L Ryan Baugh
- Department of Biology, Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708 and
| | - Patrick J Hu
- Departments of Medicine and Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
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Mata-Cabana A, Gómez-Delgado L, Romero-Expósito FJ, Rodríguez-Palero MJ, Artal-Sanz M, Olmedo M. Social Chemical Communication Determines Recovery From L1 Arrest via DAF-16 Activation. Front Cell Dev Biol 2020; 8:588686. [PMID: 33240886 PMCID: PMC7683423 DOI: 10.3389/fcell.2020.588686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/21/2020] [Indexed: 01/06/2023] Open
Abstract
In a population, chemical communication determines the response of animals to changing environmental conditions, what leads to an enhanced resistance against stressors. In response to starvation, the nematode Caenorhabditis elegans arrest post-embryonic development at the first larval stage (L1) right after hatching. As arrested L1 larvae, C. elegans become more resistant to diverse stresses, allowing them to survive for several weeks expecting to encounter more favorable conditions. L1 arrested at high densities display an enhanced resistance to starvation, dependent on soluble compounds released beyond hatching and the first day of arrest. Here, we show that this chemical communication also influences recovery after prolonged periods in L1 arrest. Animals at high density recovered faster than animals at low density. We found that the density effect on survival depends on the final effector of the insulin signaling pathway, the transcription factor DAF-16. Moreover, DAF-16 activation was higher at high density, consistent with a lower expression of the insulin-like peptide DAF-28 in the neurons. The improved recovery of animals after arrest at high density depended on soluble compounds present in the media of arrested L1s. In an effort to find the nature of these compounds, we investigated the disaccharide trehalose as putative signaling molecule, since its production is enhanced during L1 arrest and it is able to activate DAF-16. We detected the presence of trehalose in the medium of arrested L1 larvae at a low concentration. The addition of this concentration of trehalose to animals arrested at low density was enough to rescue DAF-28 production and DAF-16 activation to the levels of animals arrested at high density. However, despite activating DAF-16, trehalose was not capable of reversing survival and recovery phenotypes, suggesting the participation of additional signaling molecules. With all, here we describe a molecular mechanism underlying social communication that allows C. elegans to maintain arrested L1 larvae ready to quickly recover as soon as they encounter nutrient sources.
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Affiliation(s)
- Alejandro Mata-Cabana
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Laura Gómez-Delgado
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | | | - María J. Rodríguez-Palero
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas – Junta de Andalucía – Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain
| | - Marta Artal-Sanz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas – Junta de Andalucía – Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain
| | - María Olmedo
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
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Olmedo M, Mata‐Cabana A, Jesús Rodríguez‐Palero M, García‐Sánchez S, Fernández‐Yañez A, Merrow M, Artal‐Sanz M. Prolonged quiescence delays somatic stem cell-like divisions in Caenorhabditis elegans and is controlled by insulin signaling. Aging Cell 2020; 19:e13085. [PMID: 31852031 PMCID: PMC6996950 DOI: 10.1111/acel.13085] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/30/2019] [Accepted: 11/13/2019] [Indexed: 01/05/2023] Open
Abstract
Cells can enter quiescence in adverse conditions and resume proliferation when the environment becomes favorable. Prolonged quiescence comes with a cost, reducing the subsequent speed and potential to return to proliferation. Here, we show that a similar process happens during Caenorhabditis elegans development, providing an in vivo model to study proliferative capacity after quiescence. Hatching under starvation provokes the arrest of blast cell divisions that normally take place during the first larval stage (L1). We have used a novel method to precisely quantify each stage of postembryonic development to analyze the consequences of prolonged L1 quiescence. We report that prolonged L1 quiescence delays the reactivation of blast cell divisions in C. elegans, leading to a delay in the initiation of postembryonic development. The transcription factor DAF-16/FOXO is necessary for rapid recovery after extended arrest, and this effect is independent from its role as a suppressor of cell proliferation. Instead, the activation of DAF-16 by decreased insulin signaling reduces the rate of L1 aging, increasing proliferative potential. We also show that yolk provisioning affects the proliferative potential after L1 arrest modulating the rate of L1 aging, providing a possible mechanistic link between insulin signaling and the maintenance of proliferative potential. Furthermore, variable yolk provisioning in embryos is one of the sources of interindividual variability in recovery after quiescence of genetically identical animals. Our results support the relevance of L1 arrest as an in vivo model to study stem cell-like aging and the mechanisms for maintenance of proliferation potential after quiescence.
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Affiliation(s)
- María Olmedo
- Departamento de GenéticaFacultad de BiologíaUniversidad de SevillaSevilleSpain
| | | | - María Jesús Rodríguez‐Palero
- Andalusian Center for Developmental BiologyConsejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de OlavideSevilleSpain
- Department of Molecular Biology and Biochemical EngineeringUniversidad Pablo de OlavideSevilleSpain
| | | | - Antonio Fernández‐Yañez
- Andalusian Center for Developmental BiologyConsejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de OlavideSevilleSpain
- Department of Molecular Biology and Biochemical EngineeringUniversidad Pablo de OlavideSevilleSpain
| | - Martha Merrow
- Institute of Medical PsychologyFaculty of MedicineLMU MunichMunichGermany
| | - Marta Artal‐Sanz
- Andalusian Center for Developmental BiologyConsejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de OlavideSevilleSpain
- Department of Molecular Biology and Biochemical EngineeringUniversidad Pablo de OlavideSevilleSpain
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11
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De Rosa MJ, Veuthey T, Florman J, Grant J, Blanco MG, Andersen N, Donnelly J, Rayes D, Alkema MJ. The flight response impairs cytoprotective mechanisms by activating the insulin pathway. Nature 2019; 573:135-138. [PMID: 31462774 PMCID: PMC7986477 DOI: 10.1038/s41586-019-1524-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 07/31/2019] [Indexed: 11/09/2022]
Abstract
An animal's stress response requires different adaptive strategies depending on the nature and duration of the stressor. Whereas acute stressors, such as predation, induce a rapid and energy-demanding fight-or-flight response, long-term environmental stressors induce the gradual and long-lasting activation of highly conserved cytoprotective processes1-3. In animals across the evolutionary spectrum, continued activation of the fight-or-flight response weakens the animal's resistance to environmental challenges4,5. However, the molecular and cellular mechanisms that regulate the trade-off between the flight response and long-term stressors are poorly understood. Here we show that repeated induction of the flight response in Caenorhabditis elegans shortens lifespan and inhibits conserved cytoprotective mechanisms. The flight response activates neurons that release tyramine, an invertebrate analogue of adrenaline and noradrenaline. Tyramine stimulates the insulin-IGF-1 signalling (IIS) pathway and precludes the induction of stress response genes by activating an adrenergic-like receptor in the intestine. By contrast, long-term environmental stressors, such as heat or oxidative stress, reduce tyramine release and thereby allow the induction of cytoprotective genes. These findings demonstrate that a neural stress hormone supplies a state-dependent neural switch between acute flight and long-term environmental stress responses and provides mechanistic insights into how the flight response impairs cellular defence systems and accelerates ageing.
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Affiliation(s)
- María José De Rosa
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (CONICET), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Tania Veuthey
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (CONICET), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Jeremy Florman
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jeff Grant
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - María Gabriela Blanco
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (CONICET), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Natalia Andersen
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (CONICET), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Jamie Donnelly
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Diego Rayes
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (CONICET), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina. .,Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Mark J Alkema
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA.
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Jordan JM, Hibshman JD, Webster AK, Kaplan REW, Leinroth A, Guzman R, Maxwell CS, Chitrakar R, Bowman EA, Fry AL, Hubbard EJA, Baugh LR. Insulin/IGF Signaling and Vitellogenin Provisioning Mediate Intergenerational Adaptation to Nutrient Stress. Curr Biol 2019; 29:2380-2388.e5. [PMID: 31280992 DOI: 10.1016/j.cub.2019.05.062] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 04/19/2019] [Accepted: 05/24/2019] [Indexed: 12/22/2022]
Abstract
The roundworm C. elegans reversibly arrests larval development during starvation [1], but extended early-life starvation reduces reproductive success [2, 3]. Maternal dietary restriction (DR) buffers progeny from starvation as young larvae, preserving reproductive success [4]. However, the developmental basis of reduced fertility following early-life starvation is unknown, and it is unclear how maternal diet modifies developmental physiology in progeny. We show here that extended starvation in first-stage (L1) larvae followed by unrestricted feeding results in a variety of developmental abnormalities in the reproductive system, including proliferative germ-cell tumors and uterine masses that express neuronal and epidermal cell fate markers. We found that maternal DR and reduced maternal insulin/insulin-like growth factor (IGF) signaling (IIS) increase oocyte provisioning of vitellogenin lipoprotein, reducing penetrance of starvation-induced abnormalities in progeny, including tumors. Furthermore, we show that maternal DR and reduced maternal IIS reduce IIS in progeny. daf-16/FoxO and skn-1/Nrf, transcriptional effectors of IIS, are required in progeny for maternal DR and increased vitellogenin provisioning to suppress starvation-induced abnormalities. daf-16/FoxO activity in somatic tissues is sufficient to suppress starvation-induced abnormalities, suggesting cell-nonautonomous regulation of reproductive system development. This work reveals that early-life starvation compromises reproductive development and that vitellogenin-mediated intergenerational insulin/IGF-to-insulin/IGF signaling mediates adaptation to nutrient availability.
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Affiliation(s)
- James M Jordan
- Department of Biology, Duke University, Durham, NC 27708, USA
| | | | - Amy K Webster
- Department of Biology, Duke University, Durham, NC 27708, USA
| | | | | | - Ryan Guzman
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Colin S Maxwell
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Rojin Chitrakar
- Department of Biology, Duke University, Durham, NC 27708, USA
| | | | - Amanda L Fry
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - L Ryan Baugh
- Department of Biology, Duke University, Durham, NC 27708, USA.
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13
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Hibshman JD, Leuthner TC, Shoben C, Mello DF, Sherwood DR, Meyer JN, Baugh LR. Nonselective autophagy reduces mitochondrial content during starvation in Caenorhabditis elegans. Am J Physiol Cell Physiol 2018; 315:C781-C792. [PMID: 30133321 PMCID: PMC6336938 DOI: 10.1152/ajpcell.00109.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Starvation significantly alters cellular physiology, and signs of aging have been reported to occur during starvation. Mitochondria are essential to the regulation of cellular energetics and aging. We sought to determine whether mitochondria exhibit signs of aging during starvation and whether quality control mechanisms regulate mitochondrial physiology during starvation. We describe effects of starvation on mitochondria in the first and third larval stages of the nematode Caenorhabditis elegans. When starved, C. elegans larvae enter developmental arrest. We observed fragmentation of the mitochondrial network, a reduction in mitochondrial DNA (mtDNA) copy number, and accumulation of DNA damage during starvation-induced developmental arrest. Mitochondrial function was also compromised by starvation. Starved worms had lower basal, maximal, and ATP-linked respiration. These observations are consistent with reduced mitochondrial quality, similar to mitochondrial phenotypes during aging. Using pharmacological and genetic approaches, we found that worms deficient for autophagy were short-lived during starvation and recovered poorly from extended starvation, indicating sensitivity to nutrient stress. Autophagy mutants unc-51/Atg1 and atg-18/Atg18 maintained greater mtDNA content than wild-type worms during starvation, suggesting that autophagy promotes mitochondrial degradation during starvation. unc-51 mutants also had a proportionally smaller reduction in oxygen consumption rate during starvation, suggesting that autophagy also contributes to reduced mitochondrial function. Surprisingly, mutations in genes involved in mitochondrial fission and fusion as well as selective mitophagy of damaged mitochondria did not affect mitochondrial content during starvation. Our results demonstrate the profound influence of starvation on mitochondrial physiology with organismal consequences, and they show that these physiological effects are influenced by autophagy.
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Affiliation(s)
- Jonathan D. Hibshman
- 1Department of Biology, Duke University, Durham, North Carolina,2University Program in Genetics and Genomics, Duke University, Durham, North Carolina,3Department of Biology, University of North Carolina, Chapel Hill, North Carolina
| | - Tess C. Leuthner
- 4Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Chelsea Shoben
- 1Department of Biology, Duke University, Durham, North Carolina
| | - Danielle F. Mello
- 4Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - David R. Sherwood
- 1Department of Biology, Duke University, Durham, North Carolina,2University Program in Genetics and Genomics, Duke University, Durham, North Carolina
| | - Joel N. Meyer
- 4Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - L. Ryan Baugh
- 1Department of Biology, Duke University, Durham, North Carolina,2University Program in Genetics and Genomics, Duke University, Durham, North Carolina
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14
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Demoinet E, Roy R. Surviving Starvation: AMPK Protects Germ Cell Integrity by Targeting Multiple Epigenetic Effectors. Bioessays 2018; 40. [PMID: 29430674 DOI: 10.1002/bies.201700095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 12/18/2017] [Indexed: 12/12/2022]
Abstract
Acute starvation can have long-term consequences that are mediated through epigenetic change. Some of these changes are affected by the activity of AMP-activated protein kinase (AMPK), a master regulator of cellular energy homeostasis. In Caenorhabditis elegans, the absence of AMPK during a period of starvation in an early larval stage results in developmental defects following their recovery on food, while many of them become sterile. Moreover, the loss of AMPK during this quiescent period results in transgenerational phenotypes that can become progressively worse with each successive generation. Our recent data describe a chromatin-based mechanism of how AMPK mediates adjustment to acute starvation in the germ cells, however, the heritable aspect of this AMPK mutant phenotype remains unresolved. Here, we explore how AMPK might affect this process and speculate how the initial transcription that occurs in the germ cells may adversely affect subsequent germline gene expression and/or genomic integrity.
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Affiliation(s)
- Emilie Demoinet
- Department of Biology, McGill University, Montreal, Quebec, Canada, H3A 1B1.,Institute of Biology Valrose (iBV), CNRS, INSERM, Université Nice Sophia Antipolis, 06100, Nice, France
| | - Richard Roy
- Department of Biology, McGill University, Montreal, Quebec, Canada, H3A 1B1
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15
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Maternal age generates phenotypic variation in Caenorhabditis elegans. Nature 2017; 552:106-109. [PMID: 29186117 PMCID: PMC5736127 DOI: 10.1038/nature25012] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 11/08/2017] [Indexed: 12/20/2022]
Abstract
Genetically identical individuals growing in the same environment often show substantial phenotypic variation within populations of organisms as diverse as bacteria1, nematodes2, rodents3 and humans4. With some exceptions5, the causes are poorly understood. We show here that isogenic Caenorhabditis elegans nematodes vary in their size at hatching, speed of development, growth rate, starvation resistance, fecundity, and also in the rate of development of their germline relative to that of somatic tissues. Surprisingly, we show that the primary cause of this variation is the age of an individual’s mother, with young mothers producing progeny impaired for many traits. We identify age-dependent changes in maternal provisioning of a lipoprotein complex (vitellogenin) to embryos as the molecular mechanism underlying variation in multiple traits throughout the life of an animal. The production of sub-optimal progeny by young mothers likely reflects a trade-off between the competing fitness traits of a short generation time and progeny survival and fecundity.
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16
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AMPK blocks starvation-inducible transgenerational defects in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2017; 114:E2689-E2698. [PMID: 28289190 DOI: 10.1073/pnas.1616171114] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Life history events, such as traumatic stress, illness, or starvation, can influence us through molecular changes that are recorded in a pattern of characteristic chromatin modifications. These modifications are often associated with adaptive adjustments in gene expression that can persist throughout the lifetime of the organism, or even span multiple generations. Although these adaptations may confer some selective advantage, if they are not appropriately regulated they can also be maladaptive in a context-dependent manner. We show here that during periods of acute starvation in Caenorhabditis elegans larvae, the master metabolic regulator AMP-activated protein kinase (AMPK) plays a critical role in blocking modifications to the chromatin landscape. This ensures that gene expression remains inactive in the germ-line precursors during adverse conditions. In its absence, critical chromatin modifications occur in the primordial germ cells (PGCs) of emergent starved L1 larvae that correlate with compromised reproductive fitness of the generation that experienced the stress, but also in the subsequent generations that never experienced the initial event. Our findings suggest that AMPK regulates the activity of the chromatin modifying COMPASS complex (complex proteins associated with Set1) to ensure that chromatin marks are not established until nutrient/energy contingencies are satisfied. Our study provides molecular insight that links metabolic adaptation to transgenerational epigenetic modification in response to acute periods of starvation.
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17
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Alicea B. Evolution in eggs and phases: experimental evolution of fecundity and reproductive timing in Caenorhabditis elegans. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160496. [PMID: 28018635 PMCID: PMC5180133 DOI: 10.1098/rsos.160496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/13/2016] [Indexed: 06/06/2023]
Abstract
To examine the role of natural selection in fecundity in a variety of Caenorhabditis elegans genetic backgrounds, we used an experimental evolution protocol to evolve 14 distinct genetic strains over 15-20 generations. We were able to generate 790 distinct genealogies, which provided information on both the effects of natural selection and the evolvability of each strain. Among these genotypes are a wild-type (N2) and a collection of mutants with targeted mutations in the daf-c, daf-d and AMPK pathways. Differences are observed in reproductive fitness along with related changes in reproductive timing. The majority of selective effects on fecundity occur during the first few generations of evolution, while the negative selection for reproductive timing occurs on longer time scales. In addition, positive selection on fecundity results in positive and negative strain-dependent selection on reproductive timing. A derivative of population size per generation called reproductive carry-over (RCO) may be informative in terms of developmental selection. While these findings transcend mutations in a specific gene, changes in the RCO measure may nevertheless be products of selection. In conclusion, the broader implications of these findings are discussed, particularly in the context of genotype-fitness maps and the role of uncharacterized mutations in individual variation and evolvability.
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Affiliation(s)
- Bradly Alicea
- Orthogonal Research, Champaign, IL, USA
- OpenWorm Foundation, CA, USA
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18
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Kim J, Lee HY, Ahn J, Hyun M, Lee I, Min KJ, You YJ. NHX-5, an Endosomal Na+/H+ Exchanger, Is Associated with Metformin Action. J Biol Chem 2016; 291:18591-9. [PMID: 27435670 DOI: 10.1074/jbc.c116.744037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Indexed: 01/18/2023] Open
Abstract
Diabetes is one of the most impactful diseases worldwide. The most commonly prescribed anti-diabetic drug is metformin. In this study, we identified an endosomal Na(+)/H(+) exchanger (NHE) as a new potential target of metformin from an unbiased screen in Caenorhabditis elegans The same NHE homolog also exists in flies, where it too mediates the effects of metformin. Our results suggest that endosomal NHEs could be a metformin target and provide an insight into a novel mechanism of action of metformin on regulating the endocytic cycle.
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Affiliation(s)
- Jeongho Kim
- From the Department of Biological Sciences, Inha University, Incheon 22212, South Korea
| | - Hye-Yeon Lee
- From the Department of Biological Sciences, Inha University, Incheon 22212, South Korea
| | - Jheesoo Ahn
- the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298, and
| | - Moonjung Hyun
- the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298, and
| | - Inhwan Lee
- the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298, and
| | - Kyung-Jin Min
- From the Department of Biological Sciences, Inha University, Incheon 22212, South Korea
| | - Young-Jai You
- the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298, and the Nagoya Research Center for Brain & Neural Circuits, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
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19
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BLIMP-1/BLMP-1 and Metastasis-Associated Protein Regulate Stress Resistant Development in Caenorhabditis elegans. Genetics 2016; 203:1721-32. [PMID: 27334271 DOI: 10.1534/genetics.116.190793] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/14/2016] [Indexed: 01/17/2023] Open
Abstract
Environmental stress triggers multilevel adaptations in animal development that depend in part on epigenetic mechanisms. In response to harsh environmental conditions and pheromone signals, Caenorhabditis elegans larvae become the highly stress-resistant and long-lived dauer. Despite extensive studies of dauer formation pathways that integrate specific environmental cues and appear to depend on transcriptional reprogramming, the role of epigenetic regulation in dauer development has remained unclear. Here we report that BLMP-1, the BLIMP-1 ortholog, regulates dauer formation via epigenetic pathways; in the absence of TGF-β signaling (in daf-7 mutants), lack of blmp-1 caused lethality. Using this phenotype, we screened 283 epigenetic factors, and identified lin-40, a homolog of metastasis-associate protein 1 (MTA1) as an interactor of BLMP-1 The interaction between LIN-40 and BLMP-1 is conserved because mammalian homologs for both MTA1 and BLIMP-1 could also interact. From microarray studies, we identified several downstream target genes of blmp-1: npr-3, nhr-23, ptr-4, and sams-1 Among them S-adenosyl methionine synthase (SAMS-1), is the key enzyme for production of SAM used in histone methylation. Indeed, blmp-1 is necessary for controlling histone methylation level in daf-7 mutants, suggesting BLMP-1 regulates the expression of SAMS-1, which in turn may regulate histone methylation and dauer formation. Our results reveal a new interaction between BLMP-1/BLIMP-1 and LIN-40/MTA1, as well as potential epigenetic downstream pathways, whereby these proteins cooperate to regulate stress-specific developmental adaptations.
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20
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Roux AE, Langhans K, Huynh W, Kenyon C. Reversible Age-Related Phenotypes Induced during Larval Quiescence in C. elegans. Cell Metab 2016; 23:1113-1126. [PMID: 27304510 PMCID: PMC5794336 DOI: 10.1016/j.cmet.2016.05.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 02/09/2016] [Accepted: 05/31/2016] [Indexed: 02/07/2023]
Abstract
Cells can enter quiescent states in which cell cycling and growth are suspended. We find that during a long developmental arrest (quiescence) induced by starvation, newly hatched C. elegans acquire features associated with impaired proteostasis and aging: mitochondrial fission, ROS production, protein aggregation, decreased proteotoxic-stress resistance, and at the organismal level, decline of mobility and high mortality. All signs of aging but one, the presence of protein aggregates, were reversed upon return to development induced by feeding. The endoplasmic reticulum receptor IRE-1 is completely required for recovery, and the downstream transcription factor XBP-1, as well as a protein kinase, KGB-1, are partially required. Interestingly, kgb-1(-) mutants that do recover fail to reverse aging-like mitochondrial phenotypes and have a short adult lifespan. Our study describes the first pathway that reverses phenotypes of aging at the exit of prolonged quiescence.
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Affiliation(s)
- Antoine E Roux
- Department of Biochemistry and Biophysics, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158-2517, USA; Calico Life Sciences, 1170 Veterans Boulevard, South San Francisco, CA 94080, USA
| | - Kelley Langhans
- Department of Biochemistry and Biophysics, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158-2517, USA
| | - Walter Huynh
- Department of Biochemistry and Biophysics, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158-2517, USA
| | - Cynthia Kenyon
- Department of Biochemistry and Biophysics, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158-2517, USA; Calico Life Sciences, 1170 Veterans Boulevard, South San Francisco, CA 94080, USA.
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21
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Jobson MA, Jordan JM, Sandrof MA, Hibshman JD, Lennox AL, Baugh LR. Transgenerational Effects of Early Life Starvation on Growth, Reproduction, and Stress Resistance in Caenorhabditis elegans. Genetics 2015; 201:201-12. [PMID: 26187123 PMCID: PMC4566263 DOI: 10.1534/genetics.115.178699] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 07/15/2015] [Indexed: 11/18/2022] Open
Abstract
Starvation during early development can have lasting effects that influence organismal fitness and disease risk. We characterized the long-term phenotypic consequences of starvation during early larval development in Caenorhabditis elegans to determine potential fitness effects and develop it as a model for mechanistic studies. We varied the amount of time that larvae were developmentally arrested by starvation after hatching ("L1 arrest"). Worms recovering from extended starvation grew slowly, taking longer to become reproductive, and were smaller as adults. Fecundity was also reduced, with the smallest individuals most severely affected. Feeding behavior was impaired, possibly contributing to deficits in growth and reproduction. Previously starved larvae were more sensitive to subsequent starvation, suggesting decreased fitness even in poor conditions. We discovered that smaller larvae are more resistant to heat, but this correlation does not require passage through L1 arrest. The progeny of starved animals were also adversely affected: Embryo quality was diminished, incidence of males was increased, progeny were smaller, and their brood size was reduced. However, the progeny and grandprogeny of starved larvae were more resistant to starvation. In addition, the progeny, grandprogeny, and great-grandprogeny were more resistant to heat, suggesting epigenetic inheritance of acquired resistance to starvation and heat. Notably, such resistance was inherited exclusively from individuals most severely affected by starvation in the first generation, suggesting an evolutionary bet-hedging strategy. In summary, our results demonstrate that starvation affects a variety of life-history traits in the exposed animals and their descendants, some presumably reflecting fitness costs but others potentially adaptive.
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Affiliation(s)
- Meghan A Jobson
- Department of Biology, Duke University, Durham, North Carolina 27708
| | - James M Jordan
- Department of Biology, Duke University, Durham, North Carolina 27708
| | - Moses A Sandrof
- Department of Biology, Duke University, Durham, North Carolina 27708
| | | | - Ashley L Lennox
- Department of Biology, Duke University, Durham, North Carolina 27708
| | - L Ryan Baugh
- Department of Biology, Duke University, Durham, North Carolina 27708
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22
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Xie M, Roy R. AMP-Activated Kinase Regulates Lipid Droplet Localization and Stability of Adipose Triglyceride Lipase in C. elegans Dauer Larvae. PLoS One 2015; 10:e0130480. [PMID: 26098762 PMCID: PMC4476745 DOI: 10.1371/journal.pone.0130480] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/20/2015] [Indexed: 02/06/2023] Open
Abstract
Animals have developed diverse mechanisms to adapt to their changing environment. Like many organisms the free-living nematode C. elegans can alternate between a reproductive mode or a diapause-like "dauer" stage during larval development to circumvent harsh environmental conditions. The master metabolic regulator AMP-activated protein kinase (AMPK) is critical for survival during the dauer stage, where it phosphorylates adipose triglyceride lipase (ATGL-1) at multiple sites to block lipid hydrolysis and ultimately protect the cellular triglyceride-based energy depot from rapid depletion. However, how the AMPK-mediated phosphorylation affects the function of ATGL-1 has not been characterised at the molecular level. Here we show that AMPK phosphorylation leads to the generation of 14-3-3 binding sites on ATGL-1, which are recognized by the C. elegans 14-3-3 protein orthologue PAR-5. Physical interaction of ATGL-1 with PAR-5 results in sequestration of ATGL-1 away from the lipid droplets and eventual proteasome-mediated degradation. In addition, we also show that the major AMPK phosphorylation site on ATGL-1, Ser 303, is required for both modification of its lipid droplet localization and its degradation. Our data provide mechanistic insight as to how AMPK functions to enhance survival through its ability to protect the accumulated triglyceride deposits from rapid hydrolysis to preserve the energy stores during periods of extended environmental duress.
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Affiliation(s)
- Meng Xie
- Department of Biology, McGill University, 1205 avenue Docteur Penfield, Montreal, Canada
| | - Richard Roy
- Department of Biology, McGill University, 1205 avenue Docteur Penfield, Montreal, Canada
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23
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Tyagi R, Rosa BA, Lewis WG, Mitreva M. Pan-phylum Comparison of Nematode Metabolic Potential. PLoS Negl Trop Dis 2015; 9:e0003788. [PMID: 26000881 PMCID: PMC4441503 DOI: 10.1371/journal.pntd.0003788] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 04/24/2015] [Indexed: 01/12/2023] Open
Abstract
Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in C. elegans and the human hookworm Necator americanus. We illustrate how analyzing and comparing metabolism at the level of pathway modules can improve existing knowledge of nematode metabolic potential and can provide parasitism related insights. Our reconstruction and comparison of nematode metabolic pathways at a pan-phylum and inter-phylum level enabled determination of phylogenetic restrictions and differential expression of pathways. A visualization of our results is available at http://nematode.net and the program for identification of module completeness (modDFS) is freely available at SourceForge. The methods reported will help biologists to predict biochemical potential of any organism with available deduced proteome, to direct experiments and test hypotheses. We reconstructed metabolic pathways of 23 organisms including 13 nematode species, using their complete deduced protein coding sequences and compared them to 10 non-nematodes. We observed that metabolic potential availability is concomitant with phylogenetic and/or ecological similarity, with the exceptions providing interesting case studies. We also studied changes in metabolic profiles under different developmental stages of 4 nematode species using stage-specific transcriptomic data. A comparison of the variation patterns in these profiles led to recognition of modules that share metabolic profiles at various life-cycle stages or during development. The undertaken analysis improved genome annotation and the obtained results provided insight into parasitism, resulting in identification of taxonomically-restricted pathways and enzymes that may provide new mechanisms for control of nematode infections.
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Affiliation(s)
- Rahul Tyagi
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Bruce A. Rosa
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Warren G. Lewis
- Division of Infectious Disease, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Makedonka Mitreva
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Division of Infectious Disease, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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24
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Patananan AN, Budenholzer LM, Eskin A, Torres ER, Clarke SG. Ethanol-induced differential gene expression and acetyl-CoA metabolism in a longevity model of the nematode Caenorhabditis elegans. Exp Gerontol 2014; 61:20-30. [PMID: 25449858 DOI: 10.1016/j.exger.2014.11.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/17/2014] [Accepted: 11/16/2014] [Indexed: 01/09/2023]
Abstract
Previous studies have shown that exposing adults of the soil-dwelling nematode Caenorhabditis elegans to concentrations of ethanol in the range of 100-400mM results in slowed locomotion, decreased fertility, and reduced longevity. On the contrary, lower concentrations of ethanol (0.86-68mM) have been shown to cause a two- to three-fold increase in the life span of animals in the stress resistant L1 larval stage in the absence of a food source. However, little is known about how gene and protein expression is altered by low concentrations of ethanol and the mechanism for the increased longevity. Therefore, we used biochemical assays and next generation mRNA sequencing to identify genes and biological pathways altered by ethanol. RNA-seq analysis of L1 larvae incubated in the presence of 17mM ethanol resulted in the significant differential expression of 649 genes, 274 of which were downregulated and 375 were upregulated. Many of the genes significantly altered were associated with the conversion of ethanol and triglycerides to acetyl-CoA and glucose, suggesting that ethanol is serving as an energy source in the increased longevity of the L1 larvae as well as a signal for fat utilization. We also asked if L1 larvae could sense ethanol and respond by directed movement. Although we found that L1 larvae can chemotax to benzaldehyde, we observed little or no chemotaxis to ethanol. Understanding how low concentrations of ethanol increase the lifespan of L1 larvae may provide insight into not only the longevity pathways in C. elegans, but also in those of higher organisms.
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Affiliation(s)
| | | | - Ascia Eskin
- Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
| | - Eric Rommel Torres
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA.
| | - Steven Gerard Clarke
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA.
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25
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Extended lifespan, reduced body size and leg skeletal muscle mass, and decreased mitochondrial function in clk-1 transgenic mice. Exp Gerontol 2014; 58:146-53. [PMID: 25106098 DOI: 10.1016/j.exger.2014.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/17/2014] [Accepted: 08/04/2014] [Indexed: 12/31/2022]
Abstract
Mutational inactivation of clk-1, which encodes an enzyme necessary for the biosynthesis of coenzyme Q (CoQ), extends the lifespan of Caenorhabditis elegans. However, whether mammalian clk-1 regulates the lifespan of mice is not known because clk-1-deficiencies are embryonic lethal. Here, we investigated the lifespan of clk-1 transgenic mice (Tg96/I), which were rescued from embryonic lethality via the transgenic expression of mouse clk-1. Tg96/I mice lived longer and had smaller bodies than wild-type mice, but Tg96/I mice had CoQ levels equivalent to wild-type mice. The small-sized Tg96/I mice exhibited reduced whole-body oxygen consumption (VO2) during the dark period, and lean leg skeletal muscles with reduced mitochondrial VO2 and ATP content compared with wild-type mice. These findings indicate a close relationship between lifespan extension and decreased mitochondrial function, which was induced by the transgenic expression of clk-1, in leg skeletal muscles that exhibit high metabolic activity.
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Zajitschek S, Hotzy C, Zajitschek F, Immler S. Short-term variation in sperm competition causes sperm-mediated epigenetic effects on early offspring performance in the zebrafish. Proc Biol Sci 2014; 281:20140422. [PMID: 24789902 PMCID: PMC4024299 DOI: 10.1098/rspb.2014.0422] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 04/01/2014] [Indexed: 11/12/2022] Open
Abstract
The inheritance of non-genetic factors is increasingly seen to play a major role in ecology and evolution. While the causes and consequences of epigenetic effects transmitted from the mother to the offspring have received ample attention, much less is known about how variation in the condition of the father affects the offspring. Here, we manipulated the intensity of sperm competition experienced by male zebrafish Danio rerio to investigate the potential for sperm-mediated epigenetic effects over a relatively short period of time. We found that the rapid responses of males to varying intensity of sperm competition not only affected sperm traits as shown previously, but also the performance of the resulting offspring. We observed that males exposed to high intensity of sperm competition produced faster swimming and more motile sperm, and sired offspring that hatched over a narrower time frame but exhibited a lower survival rate than males exposed to low intensity of sperm competition. Our results provide striking evidence for short-term paternal effects and the possible fitness consequences of such sperm-mediated non-genetic factors not only for the resulting offspring but also for the female.
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Affiliation(s)
- Susanne Zajitschek
- Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden
| | - Cosima Hotzy
- Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden
| | - Felix Zajitschek
- Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden
| | - Simone Immler
- Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden
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Bentov Y, Hannam T, Jurisicova A, Esfandiari N, Casper RF. Coenzyme Q10 Supplementation and Oocyte Aneuploidy in Women Undergoing IVF-ICSI Treatment. CLINICAL MEDICINE INSIGHTS. REPRODUCTIVE HEALTH 2014; 8:31-6. [PMID: 24987272 PMCID: PMC4071761 DOI: 10.4137/cmrh.s14681] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/02/2014] [Accepted: 03/10/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND The age-related reduction in live-birth rate is attributed to a high rate of aneuploidy and follicle depletion. We showed in an animal model that treatment with Coenzyme Q10 (CoQ10) markedly improved reproductive outcome. The aim of this study was to compare the post-meiotic oocyte aneuploidy rate in in vitro fertilization (IVF) and intra cytoplasmic sperm injection (ICSI) patients treated with CoQ10 or placebo. METHODS We conducted a double blind placebo controlled randomized trial that included IVF–ICSI patients 35–43 years of age. The patients were treated with either 600 mg of CoQ10 or an equivalent number of placebo caps. We compared the post-meiotic aneuploidy rate using polar body biopsy (PBBX) and comparative genomic hybridization (CGH). According to the power calculation, 27 patients were needed for each arm. RESULTS Owing to safety concerns regarding the effects of polar body biopsy on embryo quality and implantation, the study was terminated before reaching the target number of participants. A total of 39 patients were evaluated and randomized (17 CoQ10, 22 placebo), 27 were given the study medication (12 CoQ10, 15 placebo), and 24 completed an IVF–ICSI cycle including PBBX and embryo transfer (10 CoQ10, 14 placebo). Average age, base line follicle stimulating hormone (FSH), peak estradiol and progesterone serum level, as well as the total number of human menopausal gonadotropin (hMG) units—did not differ between the groups. The rate of aneuploidy was 46.5% in the CoQ10 group compared to 62.8% in the control. Clinical pregnancy rate was 33% for the CoQ10 group and 26.7% for the control group. CONCLUSION No significant differences in outcome were detected between the CoQ10 and placebo groups. However, the final study was underpowered to detect a difference in the rate of aneuploidy.
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Affiliation(s)
- Yaakov Bentov
- Toronto Centre for Advanced Reproductive Technology, Toronto, Ontario, Canada. ; Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada. ; Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | | | - Andrea Jurisicova
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada. ; Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Navid Esfandiari
- Toronto Centre for Advanced Reproductive Technology, Toronto, Ontario, Canada. ; Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada
| | - Robert F Casper
- Toronto Centre for Advanced Reproductive Technology, Toronto, Ontario, Canada. ; Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada. ; Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
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Possik E, Jalali Z, Nouët Y, Yan M, Gingras MC, Schmeisser K, Panaite L, Dupuy F, Kharitidi D, Chotard L, Jones RG, Hall DH, Pause A. Folliculin regulates ampk-dependent autophagy and metabolic stress survival. PLoS Genet 2014; 10:e1004273. [PMID: 24763318 PMCID: PMC3998892 DOI: 10.1371/journal.pgen.1004273] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 02/14/2014] [Indexed: 12/19/2022] Open
Abstract
Dysregulation of AMPK signaling has been implicated in many human diseases, which emphasizes the importance of characterizing AMPK regulators. The tumor suppressor FLCN, responsible for the Birt-Hogg Dubé renal neoplasia syndrome (BHD), is an AMPK-binding partner but the genetic and functional links between FLCN and AMPK have not been established. Strikingly, the majority of naturally occurring FLCN mutations predisposing to BHD are predicted to produce truncated proteins unable to bind AMPK, pointing to the critical role of this interaction in the tumor suppression mechanism. Here, we demonstrate that FLCN is an evolutionarily conserved negative regulator of AMPK. Using Caenorhabditis elegans and mammalian cells, we show that loss of FLCN results in constitutive activation of AMPK which induces autophagy, inhibits apoptosis, improves cellular bioenergetics, and confers resistance to energy-depleting stresses including oxidative stress, heat, anoxia, and serum deprivation. We further show that AMPK activation conferred by FLCN loss is independent of the cellular energy state suggesting that FLCN controls the AMPK energy sensing ability. Together, our data suggest that FLCN is an evolutionarily conserved regulator of AMPK signaling that may act as a tumor suppressor by negatively regulating AMPK function. The FLCN gene is responsible for the hereditary human tumor disease called Birt-Hogg-Dube syndrome (BHD). Patients that inherit an inactivating mutation in the FLCN gene develop lung collapse as well as tumors in the kidney, colon, and skin. It is not clear yet what the exact function of this protein is in the cell or an organism. In this study, we used a simple model organism (the round worm C. elegans) to study the function of FLCN. We found that it is involved in the regulation of energy metabolism in the cell. FLCN normally binds and blocks the action of another protein (AMPK), which is involved in the maintenance of energy levels. When energy levels fall, AMPK is activated and drives a recycling pathway called autophagy, where cellular components are recycled producing energy. In the absence of FLCN in worms and mammalian cells, like in tumors of BHD patients, AMPK and autophagy are chronically activated leading to an increased energy level, which makes the cells/organism very resistant to many stresses that would normally kill them, which in the end could lead to progression of tumorigenesis.
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Affiliation(s)
- Elite Possik
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Zahra Jalali
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Yann Nouët
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Ming Yan
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Marie-Claude Gingras
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Kathrin Schmeisser
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Lorena Panaite
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Fanny Dupuy
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Physiology, McGill University, Montréal, Québec, Canada
| | - Dmitri Kharitidi
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Laëtitia Chotard
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Russell G. Jones
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Physiology, McGill University, Montréal, Québec, Canada
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Arnim Pause
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
- * E-mail:
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Wolf T, Qi W, Schindler V, Runkel ED, Baumeister R. Doxycyclin ameliorates a starvation-induced germline tumor in C. elegans daf-18/PTEN mutant background. Exp Gerontol 2014; 56:114-22. [PMID: 24746511 DOI: 10.1016/j.exger.2014.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/04/2014] [Accepted: 04/05/2014] [Indexed: 12/19/2022]
Abstract
Managing available resources is a key necessity of each organism to cope with the environment. The nematode C. elegans responds to nutritional deprivation or harsh environmental conditions with a multitude of developmental adaptations, among them a starvation-induced quiescence at early larval development (L1). daf-18, the C. elegans homolog of the human tumor suppressor gene PTEN, is essential for the maintenance of survival and germline stem cell arrest during the L1 diapause. We show here that daf-18 mutants, independently to their failure to maintain G2 arrest of the primordial germ cells, develop a gonad phenotype after refeeding. This highly penetrant gonadal phenotype is further enhanced by a mutation in shc-1, encoding a protein homologous to the human adaptor ShcA. Features of this phenotype are a tumor-like phenotype encompassing hyper-proliferation of germ cell nuclei and disruption/invasion of the basement membrane surrounding the gonad. The penetrance of this phenotype is reduced by decreasing starvation temperature. In addition, it is also ameliorated in a dose-dependent way by exposure to the antibiotic doxycyclin either during starvation or during subsequent refeeding. Since, in eukaryotic cells, doxycyclin specifically blocks mitochondrial translation, our results suggest that daf-18 and shc-1;daf-18 mutants fail to adapt mitochondrial activity to reduced nutritional availability during early larval developing.
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Affiliation(s)
- Tim Wolf
- Faculty of Biology, Institute of Biology III, Albert-Ludwigs-University, D-79104 Freiburg, Germany
| | - Wenjing Qi
- Faculty of Biology, Institute of Biology III, Albert-Ludwigs-University, D-79104 Freiburg, Germany
| | - Verena Schindler
- Faculty of Biology, Institute of Biology III, Albert-Ludwigs-University, D-79104 Freiburg, Germany
| | - Eva Diana Runkel
- Faculty of Biology, Institute of Biology III, Albert-Ludwigs-University, D-79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine, Albert-Ludwigs-University, D-79104 Freiburg, Germany
| | - Ralf Baumeister
- Faculty of Biology, Institute of Biology III, Albert-Ludwigs-University, D-79104 Freiburg, Germany; Faculty of Medicine, ZBMZ Centre of Biochemistry and Molecular Cell Research, Albert-Ludwigs-University, D-79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University, D-79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine, Albert-Ludwigs-University, D-79104 Freiburg, Germany.
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Abstract
Stem cells exert precise regulation to maintain a balance of self-renewal and differentiation programs to sustain tissue homeostasis throughout the life of an organism. Recent evidence suggests that this regulation is modulated, in part, via metabolic changes and modifications of nutrient-sensing pathways such as mTOR and AMPK. It is becoming increasingly clear that stem cells inhibit oxidative phosphorylation in favor of aerobic glycolysis for energy production. Recent progress has detailed the molecular mechanisms of this metabolic phenotype and has offered insight into new metabolic pathways that may be involved in stem cell homeostasis.
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Affiliation(s)
- Joshua D Ochocki
- Abramson Family Cancer Research Institute, 2 Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
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Density dependence in Caenorhabditis larval starvation. Sci Rep 2013; 3:2777. [PMID: 24071624 PMCID: PMC3784960 DOI: 10.1038/srep02777] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 09/10/2013] [Indexed: 01/15/2023] Open
Abstract
Availability of food is often a limiting factor in nature. Periods of food abundance are followed by times of famine, often in unpredictable patterns. Reliable information about the environment is a critical ingredient of successful survival strategy. One way to improve accuracy is to integrate information communicated by other organisms. To test whether such exchange of information may play a role in determining starvation survival strategies, we studied starvation of L1 larvae in C. elegans and other Caenorhabditis species. We found that some species in genus Caenorhabditis, including C. elegans, survive longer when starved at higher densities, while for others survival is independent of the density. The density effect is mediated by chemical signal(s) that worms release during starvation. This starvation survival signal is independent of ascarosides, a class of small molecules widely used in chemical communication of C. elegans and other nematodes.
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Abstract
Availability of food is often a limiting factor in nature. Periods of food abundance are followed by times of famine, often in unpredictable patterns. Reliable information about the environment is a critical ingredient of successful survival strategy. One way to improve accuracy is to integrate information communicated by other organisms. To test whether such exchange of information may play a role in determining starvation survival strategies, we studied starvation of L1 larvae in C. elegans and other Caenorhabditis species. We found that some species in genus Caenorhabditis, including C. elegans, survive longer when starved at higher densities, while for others survival is independent of the density. The density effect is mediated by chemical signal(s) that worms release during starvation. This starvation survival signal is independent of ascarosides, a class of small molecules widely used in chemical communication of C. elegans and other nematodes.
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Affiliation(s)
- Alexander B Artyukhin
- 1] Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850, USA [2] Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA 23298, USA
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Tsuyama T, Kishikawa JI, Han YW, Harada Y, Tsubouchi A, Noji H, Kakizuka A, Yokoyama K, Uemura T, Imamura H. In vivo fluorescent adenosine 5'-triphosphate (ATP) imaging of Drosophila melanogaster and Caenorhabditis elegans by using a genetically encoded fluorescent ATP biosensor optimized for low temperatures. Anal Chem 2013; 85:7889-96. [PMID: 23875533 DOI: 10.1021/ac4015325] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Adenosine 5'-triphosphate (ATP) is the major energy currency of all living organisms. Despite its important functions, the spatiotemporal dynamics of ATP levels inside living multicellular organisms is unclear. In this study, we modified the genetically encoded Förster resonance energy transfer (FRET)-based ATP biosensor ATeam to optimize its affinity at low temperatures. This new biosensor, AT1.03NL, detected ATP changes inside Drosophila S2 cells more sensitively than the original biosensor did, at 25 °C. By expressing AT1.03NL in Drosophila melanogaster and Caenorhabditis elegans, we succeeded in imaging the in vivo ATP dynamics of these model animals at single-cell resolution.
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Affiliation(s)
- Taiichi Tsuyama
- Graduate School of Biostudies, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
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Reina A, Subramaniam AB, Laromaine A, Samuel ADT, Whitesides GM. Shifts in the distribution of mass densities is a signature of caloric restriction in Caenorhabditis elegans. PLoS One 2013; 8:e69651. [PMID: 23922767 PMCID: PMC3726776 DOI: 10.1371/journal.pone.0069651] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 06/13/2013] [Indexed: 12/30/2022] Open
Abstract
Although the starvation response of the model multicellular organism Caenorhabditis elegans is a subject of much research, there is no convenient phenotypic readout of caloric restriction that can be applicable to large numbers of worms. This paper describes the distribution of mass densities of populations of C. elegans, from larval stages up to day one of adulthood, using isopycnic centrifugation, and finds that density is a convenient, if complex, phenotypic readout in C. elegans. The density of worms in synchronized populations of wildtype N2 C. elegans grown under standard solid-phase culture conditions was normally distributed, with distributions peaked sharply at a mean of 1.091 g/cm3 for L1, L2 and L3 larvae, 1.087 g/cm3 for L4 larvae, 1.081 g/cm3 for newly molted adults, and 1.074 g/cm3 at 24 hours of adulthood. The density of adult worms under starvation stress fell well outside this range, falling to a mean value of 1.054 g/cm3 after eight hours of starvation. This decrease in density correlated with the consumption of stored glycogen in the food-deprived worms. The density of the worms increased when deprived of food for longer durations, corresponding to a shift in the response of the worms: worms sacrifice their bodies by retaining larvae, which consume the adults from within. Density-based screens with the drug Ivermectin on worms cultured on single plates resulted in a clear bimodal (double-peaked) distribution of densities corresponding to drug exposed and non-exposed worms. Thus, measurements of changes in density could be used to conduct screens on the effects of drugs on several populations of worms cultured on single plates.
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Affiliation(s)
- Alfonso Reina
- Department of Chemistry and Chemical Biology, Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Anand Bala Subramaniam
- Department of Chemistry and Chemical Biology, Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Anna Laromaine
- Department of Chemistry and Chemical Biology, Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Aravinthan D. T. Samuel
- Department of Physics and Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - George M. Whitesides
- Department of Chemistry and Chemical Biology, Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail:
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Baugh LR. To grow or not to grow: nutritional control of development during Caenorhabditis elegans L1 arrest. Genetics 2013; 194:539-55. [PMID: 23824969 PMCID: PMC3697962 DOI: 10.1534/genetics.113.150847] [Citation(s) in RCA: 176] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/09/2013] [Indexed: 12/30/2022] Open
Abstract
It is widely appreciated that larvae of the nematode Caenorhabditis elegans arrest development by forming dauer larvae in response to multiple unfavorable environmental conditions. C. elegans larvae can also reversibly arrest development earlier, during the first larval stage (L1), in response to starvation. "L1 arrest" (also known as "L1 diapause") occurs without morphological modification but is accompanied by increased stress resistance. Caloric restriction and periodic fasting can extend adult lifespan, and developmental models are critical to understanding how the animal is buffered from fluctuations in nutrient availability, impacting lifespan. L1 arrest provides an opportunity to study nutritional control of development. Given its relevance to aging, diabetes, obesity and cancer, interest in L1 arrest is increasing, and signaling pathways and gene regulatory mechanisms controlling arrest and recovery have been characterized. Insulin-like signaling is a critical regulator, and it is modified by and acts through microRNAs. DAF-18/PTEN, AMP-activated kinase and fatty acid biosynthesis are also involved. The nervous system, epidermis, and intestine contribute systemically to regulation of arrest, but cell-autonomous signaling likely contributes to regulation in the germline. A relatively small number of genes affecting starvation survival during L1 arrest are known, and many of them also affect adult lifespan, reflecting a common genetic basis ripe for exploration. mRNA expression is well characterized during arrest, recovery, and normal L1 development, providing a metazoan model for nutritional control of gene expression. In particular, post-recruitment regulation of RNA polymerase II is under nutritional control, potentially contributing to a rapid and coordinated response to feeding. The phenomenology of L1 arrest will be reviewed, as well as regulation of developmental arrest and starvation survival by various signaling pathways and gene regulatory mechanisms.
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Affiliation(s)
- L Ryan Baugh
- Department of Biology, Duke Center for Systems Biology, Duke University, Durham, North Carolina 27708-0338, USA.
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Artyukhin AB, Yim JJ, Srinivasan J, Izrayelit Y, Bose N, von Reuss SH, Jo Y, Jordan JM, Baugh LR, Cheong M, Sternberg PW, Avery L, Schroeder FC. Succinylated octopamine ascarosides and a new pathway of biogenic amine metabolism in Caenorhabditis elegans. J Biol Chem 2013; 288:18778-83. [PMID: 23689506 PMCID: PMC3696653 DOI: 10.1074/jbc.c113.477000] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/13/2013] [Indexed: 11/06/2022] Open
Abstract
The ascarosides, small-molecule signals derived from combinatorial assembly of primary metabolism-derived building blocks, play a central role in Caenorhabditis elegans biology and regulate many aspects of development and behavior in this model organism as well as in other nematodes. Using HPLC-MS/MS-based targeted metabolomics, we identified novel ascarosides incorporating a side chain derived from succinylation of the neurotransmitter octopamine. These compounds, named osas#2, osas#9, and osas#10, are produced predominantly by L1 larvae, where they serve as part of a dispersal signal, whereas these ascarosides are largely absent from the metabolomes of other life stages. Investigating the biogenesis of these octopamine-derived ascarosides, we found that succinylation represents a previously unrecognized pathway of biogenic amine metabolism. At physiological concentrations, the neurotransmitters serotonin, dopamine, and octopamine are converted to a large extent into the corresponding succinates, in addition to the previously described acetates. Chemically, bimodal deactivation of biogenic amines via acetylation and succinylation parallels posttranslational modification of proteins via acetylation and succinylation of L-lysine. Our results reveal a small-molecule connection between neurotransmitter signaling and interorganismal regulation of behavior and suggest that ascaroside biosynthesis is based in part on co-option of degradative biochemical pathways.
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Affiliation(s)
- Alexander B. Artyukhin
- From the Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
- the Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Joshua J. Yim
- From the Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Jagan Srinivasan
- the Howard Hughes Medical Institute and Division of Biology, California Institute of Technology, Pasadena, California 91125, and
| | - Yevgeniy Izrayelit
- From the Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Neelanjan Bose
- From the Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Stephan H. von Reuss
- From the Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Yeara Jo
- the Howard Hughes Medical Institute and Division of Biology, California Institute of Technology, Pasadena, California 91125, and
| | - James M. Jordan
- the Department of Biology, Duke Center for Systems Biology, Duke University, Durham, North Carolina 27708
| | - L. Ryan Baugh
- the Department of Biology, Duke Center for Systems Biology, Duke University, Durham, North Carolina 27708
| | - Micheong Cheong
- the Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Paul W. Sternberg
- the Howard Hughes Medical Institute and Division of Biology, California Institute of Technology, Pasadena, California 91125, and
| | - Leon Avery
- the Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Frank C. Schroeder
- From the Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
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