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Odoh CK, Madrigal-Perez LA, Kamal R. Glucosylglycerol and proline reverse the effects of glucose on Rhodosporidium toruloides lifespan. Arch Microbiol 2024; 206:195. [PMID: 38546876 DOI: 10.1007/s00203-024-03930-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 03/11/2024] [Accepted: 03/13/2024] [Indexed: 04/02/2024]
Abstract
Rhodosporidium toruloides is a novel cell factory used to synthesis carotenoids, biosurfactants, and biofuel feedstocks. However, research on R. toruloides has generally centred on the manufacture of biochemicals, while analyses of its longevity have received scant attention. Understanding of R. toruloides longevity under different nutrient conditions could help to improve its biotechnological significance and metabolite production. Glucosylglycerol (GG) and proline are osmoprotectants that could revert the harmful effects of environmental stress. This study examined how GG and proline affect R. toruloides strain longevity under glucose nutrimental stress. Herein, we provide evidence that GG and proline enhance cell performance and viability. These compatible solutes neutralises the pro-ageing effects of high glucose (10% glucose) on the yeast cell and reverse its cellular stress. GG exhibits the greatest impact on lifespan extension at 100 mM, whereas proline exerts effect at 2 mM. Our data reveal that these compounds significantly affect the culture medium osmolarity. Moreso, GG and proline decreased ROS production and mitohormetic lifespan regulation, respectively. The data indicates that these solutes (proline and GG) support the longevity of R. toruloides at a pro-ageing high glucose culture condition.
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Affiliation(s)
- Chuks Kenneth Odoh
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Rd, Dalian, 116023, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | | | - Rasool Kamal
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Rd, Dalian, 116023, China
- Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Rd, Dalian, 116023, China
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2
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Chadwick SR, Fazio EN, Etedali-Zadeh P, Genereaux J, Duennwald ML, Lajoie P. A functional unfolded protein response is required for chronological aging in Saccharomyces cerevisiae. Curr Genet 2019; 66:263-277. [PMID: 31346745 DOI: 10.1007/s00294-019-01019-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 07/08/2019] [Accepted: 07/16/2019] [Indexed: 12/29/2022]
Abstract
Progressive impairment of proteostasis and accumulation of toxic misfolded proteins are associated with the cellular aging process. Here, we employed chronologically aged yeast cells to investigate how activation of the unfolded protein response (UPR) upon accumulation of misfolded proteins in the endoplasmic reticulum (ER) affects lifespan. We found that cells lacking a functional UPR display a significantly reduced chronological lifespan, which contrasts previous findings in models of replicative aging. We find exacerbated UPR activation in aged cells, indicating an increase in misfolded protein burden in the ER during the course of aging. We also observed that caloric restriction, which promotes longevity in various model organisms, extends lifespan of UPR-deficient strains. Similarly, aging in pH-buffered media extends lifespan, albeit independently of the UPR. Thus, our data support a role for caloric restriction and reduced acid stress in improving ER homeostasis during aging. Finally, we show that UPR-mediated upregulation of the ER chaperone Kar2 and functional ER-associated degradation (ERAD) are essential for proper aging. Our work documents the central role of secretory protein homeostasis in chronological aging in yeast and highlights that the requirement for a functional UPR can differ between post-mitotic and actively dividing eukaryotic cells.
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Affiliation(s)
- Sarah R Chadwick
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, N6A 5C1, Canada
| | - Elena N Fazio
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, N6A 5C1, Canada
| | - Parnian Etedali-Zadeh
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, N6A 5C1, Canada
| | - Julie Genereaux
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, N6A 5C1, Canada.,Department of Biochemistry, The University of Western Ontario, London, N6A 5C1, Canada
| | - Martin L Duennwald
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, N6A 5C1, Canada.,Department of Pathology and Laboratory Medicine, The University of Western Ontario, London, N6A 5C1, Canada
| | - Patrick Lajoie
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, N6A 5C1, Canada.
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3
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Smith DL, Maharrey CH, Carey CR, White RA, Hartman JL. Gene-nutrient interaction markedly influences yeast chronological lifespan. Exp Gerontol 2016; 86:113-123. [PMID: 27125759 PMCID: PMC5079838 DOI: 10.1016/j.exger.2016.04.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 04/14/2016] [Accepted: 04/18/2016] [Indexed: 02/01/2023]
Abstract
PURPOSE Research into the genetic mechanisms of aging has expanded rapidly over the past two decades. This has in part been the result of the use of model organisms (particularly yeast, worms and flies) and high-throughput technologies, combined with a growing interest in aging research. Despite this progress, widespread consensus regarding the pathways that are fundamental to the modulation of cellular aging and lifespan for all organisms has been limited due to discrepancies between different studies. We have compared results from published genome-wide, chronological lifespan (CLS) screens of individual gene deletion strains in Saccharomyces cerevisiae in order to identify gene deletion strains with consistent influences on longevity as possible indicators of fundamental aging processes from this single-celled, eukaryotic model organism. METHODS Three previous reports have described genetic modifiers of chronological aging in the budding yeast (S. cerevisiae) using the yeast gene deletion strain collection. We performed a comparison among the data sets using correlation and decile distribution analysis to describe concordance between screens and identify strains that consistently increased or decreased CLS. We used gene enrichment analysis in an effort to understand the biology underlying genes identified in multiple studies. We attempted to replicate the different experimental conditions employed by the screens to identify potential sources of variability in CLS worth further investigating. RESULTS Among 3209 strains present in all three screens, nine deletions strains were in common in the longest-lived decile (2.80%) and thirteen were in common in the shortest-lived decile (4.05%) of all three screens. Similarly, pairwise overlap between screens was low. When the same comparison was extended to three deciles to include more mutants studied in common between the three screens, enrichment of cellular processes based on gene ontology analysis in the long-lived strains remained very limited. To test the hypothesis that different parental strain auxotrophic requirements or media formulations employed by the respective genome-wide screens might contribute to the lack of concordance, different CLS assay conditions were assessed in combination with strains having different ploidy and auxotrophic requirements (all relevant to differences in the way the three genome-wide CLS screens were performed). This limited but systematic analysis of CLS with respect to auxotrophy, ploidy, and media revealed several instances of gene-nutrient interaction. CONCLUSIONS There is surprisingly little overlap between the results of three independently performed genome-wide screens of CLS in S. cerevisiae. However, differences in strain genetic background (ploidy and specific auxotrophic requirements) were present, as well as different media and experimental conditions (e.g., aeration and pooled vs. individual culturing), which, along with stochastic effects such as genetic drift or selection of secondary mutations that suppress the loss of function from gene deletion, could in theory account for some of the lack of consensus between results. Considering the lack of overlap in CLS phenotypes among the set of genes reported by all three screens, and the results of a CLS experiment that systematically tested (incorporating extensive controls) for interactions between variables existing between the screens, we propose that discrepancies can be reconciled through deeper understanding of the influence of cell intrinsic factors such as auxotrophic requirements ploidy status, extrinsic factors such as media composition and aeration, as well as interactions that may occur between them, for example as a result of different pooling vs. individually aging cultures. Such factors may have a more significant impact on CLS outcomes than previously realized. Future studies that systematically account for these contextual factors, and can thus clarify the interactions between genetic and nutrient factors that alter CLS phenotypes, should aid more complete understanding of the underlying biology so that genetic principles of CLS in yeast can be extrapolated to differential cellular aging observed in animal models.
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Affiliation(s)
- Daniel L Smith
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Comprehensive Center for Healthy Aging, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Crystal H Maharrey
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Christopher R Carey
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Richard A White
- Department of Statistics and Michael Smith Laboratories, University of British Columbia,3182 Earth Sciences Building, 2207 Main Mall, Vancouver BC V6T-1Z4, Canada
| | - John L Hartman
- Nathan Shock Center of Excellence in the Basic Biology of Aging, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Comprehensive Center for Healthy Aging, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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4
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Chadwick SR, Pananos AD, Di Gregorio SE, Park AE, Etedali-Zadeh P, Duennwald ML, Lajoie P. A Toolbox for Rapid Quantitative Assessment of Chronological Lifespan and Survival inSaccharomyces cerevisiae. Traffic 2016; 17:689-703. [DOI: 10.1111/tra.12391] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/01/2016] [Accepted: 03/01/2016] [Indexed: 01/01/2023]
Affiliation(s)
- Sarah R. Chadwick
- Department of Anatomy and Cell Biology; The University of Western Ontario; London N6A 5C1 Canada
| | | | - Sonja E. Di Gregorio
- Department of Pathology and Laboratory Medicine; The University of Western Ontario; London N6A 5C1 Canada
| | - Anna E. Park
- Department of Anatomy and Cell Biology; The University of Western Ontario; London N6A 5C1 Canada
| | - Parnian Etedali-Zadeh
- Department of Anatomy and Cell Biology; The University of Western Ontario; London N6A 5C1 Canada
| | - Martin L. Duennwald
- Department of Anatomy and Cell Biology; The University of Western Ontario; London N6A 5C1 Canada
- Department of Pathology and Laboratory Medicine; The University of Western Ontario; London N6A 5C1 Canada
| | - Patrick Lajoie
- Department of Anatomy and Cell Biology; The University of Western Ontario; London N6A 5C1 Canada
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5
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Arlia-Ciommo A, Leonov A, Piano A, Svistkova V, Titorenko VI. Cell-autonomous mechanisms of chronological aging in the yeast Saccharomyces cerevisiae. MICROBIAL CELL 2014; 1:163-178. [PMID: 28357241 PMCID: PMC5354559 DOI: 10.15698/mic2014.06.152] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A body of evidence supports the view that the signaling pathways governing
cellular aging - as well as mechanisms of their modulation by
longevity-extending genetic, dietary and pharmacological interventions - are
conserved across species. The scope of this review is to critically analyze
recent advances in our understanding of cell-autonomous mechanisms of
chronological aging in the budding yeast Saccharomyces
cerevisiae. Based on our analysis, we propose a concept of a
biomolecular network underlying the chronology of cellular aging in yeast. The
concept posits that such network progresses through a series of lifespan
checkpoints. At each of these checkpoints, the intracellular concentrations of
some key intermediates and products of certain metabolic pathways - as well as
the rates of coordinated flow of such metabolites within an intricate network of
intercompartmental communications - are monitored by some checkpoint-specific
ʺmaster regulatorʺ proteins. The concept envisions that a synergistic action of
these master regulator proteins at certain early-life and late-life checkpoints
modulates the rates and efficiencies of progression of such processes as cell
metabolism, growth, proliferation, stress resistance, macromolecular
homeostasis, survival and death. The concept predicts that, by modulating these
vital cellular processes throughout lifespan (i.e., prior to an arrest of cell
growth and division, and following such arrest), the checkpoint-specific master
regulator proteins orchestrate the development and maintenance of a pro- or
anti-aging cellular pattern and, thus, define longevity of chronologically aging
yeast.
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Affiliation(s)
| | - Anna Leonov
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Amanda Piano
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Veronika Svistkova
- Department of Biology, Concordia University, Montreal, Quebec H4B 1R6, Canada
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6
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Mirisola MG, Braun RJ, Petranovic D. Approaches to study yeast cell aging and death. FEMS Yeast Res 2013; 14:109-18. [DOI: 10.1111/1567-1364.12112] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 10/08/2013] [Accepted: 10/08/2013] [Indexed: 11/26/2022] Open
Affiliation(s)
| | - Ralf J. Braun
- Institut für Zellbiologie; Universität Bayreuth; Bayreuth Germany
| | - Dina Petranovic
- Department of Chemical and Biological Engineering, Systems and Synthetic Biology; Chalmers University of Technology; Göteborg Sweden
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7
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Blagosklonny MV. Aging is not programmed: genetic pseudo-program is a shadow of developmental growth. Cell Cycle 2013; 12:3736-42. [PMID: 24240128 PMCID: PMC3905065 DOI: 10.4161/cc.27188] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Aging is not and cannot be programmed. Instead, aging is a continuation of developmental growth, driven by genetic pathways such as mTOR. Ironically, this is often misunderstood as a sort of programmed aging. In contrast, aging is a purposeless quasi-program or, figuratively, a shadow of actual programs. “The brightest flame casts the darkest shadow.” -George Martin
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8
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Delaney JR, Ahmed U, Chou A, Sim S, Carr D, Murakami CJ, Schleit J, Sutphin GL, An EH, Castanza A, Fletcher M, Higgins S, Jelic M, Klum S, Muller B, Peng ZJ, Rai D, Ros V, Singh M, Wende HV, Kennedy BK, Kaeberlein M. Stress profiling of longevity mutants identifies Afg3 as a mitochondrial determinant of cytoplasmic mRNA translation and aging. Aging Cell 2013; 12:156-66. [PMID: 23167605 DOI: 10.1111/acel.12032] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2012] [Indexed: 01/05/2023] Open
Abstract
Although environmental stress likely plays a significant role in promoting aging, the relationship remains poorly understood. To characterize this interaction in a more comprehensive manner, we examined the stress response profiles for 46 long-lived yeast mutant strains across four different stress conditions (oxidative, ER, DNA damage, and thermal), grouping genes based on their associated stress response profiles. Unexpectedly, cells lacking the mitochondrial AAA protease gene AFG3 clustered strongly with long-lived strains lacking cytosolic ribosomal proteins of the large subunit. Similar to these ribosomal protein mutants, afg3Δ cells show reduced cytoplasmic mRNA translation, enhanced resistance to tunicamycin that is independent of the ER unfolded protein response, and Sir2-independent but Gcn4-dependent lifespan extension. These data demonstrate an unexpected link between a mitochondrial protease, cytoplasmic mRNA translation, and aging.
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Affiliation(s)
| | - Umema Ahmed
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Annie Chou
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Sylvia Sim
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Daniel Carr
- Department of Pathology; University of Washington; Seattle; WA; USA
| | | | - Jennifer Schleit
- Department of Pathology; University of Washington; Seattle; WA; USA
| | | | - Elroy H. An
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Anthony Castanza
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Marissa Fletcher
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Sean Higgins
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Monika Jelic
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Shannon Klum
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Brian Muller
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Zhao J. Peng
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Dilreet Rai
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Vanessa Ros
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Minnie Singh
- Department of Pathology; University of Washington; Seattle; WA; USA
| | - Helen V. Wende
- Department of Pathology; University of Washington; Seattle; WA; USA
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9
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Delaney JR, Murakami C, Chou A, Carr D, Schleit J, Sutphin GL, An EH, Castanza AS, Fletcher M, Goswami S, Higgins S, Holmberg M, Hui J, Jelic M, Jeong KS, Kim JR, Klum S, Liao E, Lin MS, Lo W, Miller H, Moller R, Peng ZJ, Pollard T, Pradeep P, Pruett D, Rai D, Ros V, Schuster A, Singh M, Spector BL, Wende HV, Wang AM, Wasko BM, Olsen B, Kaeberlein M. Dietary restriction and mitochondrial function link replicative and chronological aging in Saccharomyces cerevisiae. Exp Gerontol 2012; 48:1006-13. [PMID: 23235143 DOI: 10.1016/j.exger.2012.12.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Revised: 11/27/2012] [Accepted: 12/03/2012] [Indexed: 12/30/2022]
Abstract
Chronological aging of budding yeast cells results in a reduction in subsequent replicative life span through unknown mechanisms. Here we show that dietary restriction during chronological aging delays the reduction in subsequent replicative life span up to at least 23days of chronological age. We further show that among the viable portion of the control population aged 26days, individual cells with the lowest mitochondrial membrane potential have the longest subsequent replicative lifespan. These observations demonstrate that dietary restriction modulates a common molecular mechanism linking chronological and replicative aging in yeast and indicate a critical role for mitochondrial function in this process.
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Affiliation(s)
- Joe R Delaney
- Department of Pathology, University of Washington, Seattle, WA 98195-7470, USA
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10
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Murakami C, Delaney JR, Chou A, Carr D, Schleit J, Sutphin GL, An EH, Castanza AS, Fletcher M, Goswami S, Higgins S, Holmberg M, Hui J, Jelic M, Jeong KS, Kim JR, Klum S, Liao E, Lin MS, Lo W, Miller H, Moller R, Peng ZJ, Pollard T, Pradeep P, Pruett D, Rai D, Ros V, Schuster A, Singh M, Spector BL, Vander Wende H, Wang AM, Wasko BM, Olsen B, Kaeberlein M. pH neutralization protects against reduction in replicative lifespan following chronological aging in yeast. Cell Cycle 2012; 11:3087-96. [PMID: 22871733 DOI: 10.4161/cc.21465] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Chronological and replicative aging have been studied in yeast as alternative paradigms for post-mitotic and mitotic aging, respectively. It has been known for more than a decade that cells of the S288C background aged chronologically in rich medium have reduced replicative lifespan relative to chronologically young cells. Here we report replication of this observation in the diploid BY4743 strain background. We further show that the reduction in replicative lifespan from chronological aging is accelerated when cells are chronologically aged under standard conditions in synthetic complete medium rather than rich medium. The loss of replicative potential with chronological age is attenuated by buffering the pH of the chronological aging medium to 6.0, an intervention that we have previously shown can extend chronological lifespan. These data demonstrate that extracellular acidification of the culture medium can cause intracellular damage in the chronologically aging population that is asymmetrically segregated by the mother cell to limit subsequent replicative lifespan.
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11
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Extension of Chronological Lifespan by Hexokinase Mutation in Kluyveromyces lactis Involves Increased Level of the Mitochondrial Chaperonin Hsp60. J Aging Res 2012; 2012:946586. [PMID: 22675632 PMCID: PMC3362934 DOI: 10.1155/2012/946586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 02/28/2012] [Accepted: 03/08/2012] [Indexed: 11/17/2022] Open
Abstract
Oxidative damage, mitochondrial dysfunction, genomic instability, and telomere shortening represent all molecular processes proposed as causal factors in aging. Lifespan can be increased by metabolism through an influence on such processes. Glucose reduction extends chronological lifespan (CLS) of Saccharomyces cerevisiae through metabolic adaptation to respiration. To answer the question if the reduced CLS could be ascribed to glucose per se or to glucose repression of respiratory enzymes, we used the Kluyveromyces lactis yeast, where glucose repression does not affect the respiratory function. We identified the unique hexokinase, encoded by RAG5 gene, as an important player in influencing yeast lifespan by modulating mitochondrial functionality and the level of the mitochondrial chaperonin Hsp60. In this context, this hexokinase might have a regulatory role in the influence of CLS, shedding new light on the complex regulation played by hexokinases.
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12
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Conserved role of medium acidification in chronological senescence of yeast and mammalian cells. Aging (Albany NY) 2012; 3:1127-9. [PMID: 22184281 PMCID: PMC3276382 DOI: 10.18632/aging.100412] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Abstract
When investigating aging it is important to focus on the factors that are needed to attain, and which can be manipulated to extend, the longest lifespans. This has long been appreciated by those workers who use Drosophila or Caenorhabditis elegans as model experimental systems to study aging. Often though it seems it is not a consideration in many studies of yeast chronological aging. In this chapter I summarise how recent work has revealed the preconditioning that is needed for yeast to survive for long periods in stationary phase, therefore for it to exhibit a long chronological life span (CLS). Of critical importance in this regard is the nature of the nutrient limitation that, during the earlier growth phase, had forced the cells to undergo growth arrest. I have attempted to highlight those studies that have focussed on the longest CLSs, as this helps to identify investigations that may be addressing - not just factors that can influence chronological longevity - but those factors that are correlated with the authentic processes of chronological aging. Attempting to maximize long-term stationary survival in yeast should also enhance the potential relevance of this organism as an aging model to those who wrestle with the problems of aging in more complex systems. Finally I also give a personal perspective of how studies on the yeast CLS may still yet provide some important new insights into events that are correlated with aging.
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Affiliation(s)
- Peter W Piper
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, S10 2TN, UK,
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14
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Murakami CJ, Wall V, Basisty N, Kaeberlein M. Composition and acidification of the culture medium influences chronological aging similarly in vineyard and laboratory yeast. PLoS One 2011; 6:e24530. [PMID: 21949725 PMCID: PMC3176285 DOI: 10.1371/journal.pone.0024530] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 08/11/2011] [Indexed: 11/17/2022] Open
Abstract
Chronological aging has been studied extensively in laboratory yeast by culturing cells into stationary phase in synthetic complete medium with 2% glucose as the carbon source. During this process, acidification of the culture medium occurs due to secretion of organic acids, including acetic acid, which limits survival of yeast cells. Dietary restriction or buffering the medium to pH 6 prevents acidification and increases chronological life span. Here we set out to determine whether these effects are specific to laboratory-derived yeast by testing the chronological aging properties of the vineyard yeast strain RM11. Similar to the laboratory strain BY4743 and its haploid derivatives, RM11 and its haploid derivatives displayed increased chronological life span from dietary restriction, buffering the pH of the culture medium, or aging in rich medium. RM11 and BY4743 also displayed generally similar aging and growth characteristics when cultured in a variety of different carbon sources. These data support the idea that mechanisms of chronological aging are similar in both the laboratory and vineyard strains.
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Affiliation(s)
- Christopher J Murakami
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
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15
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Wu Z, Song L, Liu SQ, Huang D. A high throughput screening assay for determination of chronological lifespan of yeast. Exp Gerontol 2011; 46:915-22. [PMID: 21871551 DOI: 10.1016/j.exger.2011.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 08/02/2011] [Accepted: 08/06/2011] [Indexed: 12/20/2022]
Abstract
A high throughput screening assay was developed based on the yeast chronological aging model and applied in evaluating several factors that mediate lifespan, including inoculum size, cellular state in nutrient-rich medium, and calorie level. Using our assay, we confirmed the previously reported genetic mimics of calorie restriction, including deletion of TOR1, SCH9 or RAS2. In contrast, deletion of SIR2 had longevity effect but seemed to produce only small beneficial effect on the response to calorie restriction. Overall, this new high throughput screening assay may facilitate identification of calorie restriction mimetics with a rapid and simple protocol, uncomplicated data analysis, and high sensitivity. In addition, the assay also provides quantifiable data including lag-time, growth rate, doubling time, and survival percentage.
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Affiliation(s)
- Ziyun Wu
- Food Science and Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 3, Singapore.
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16
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Burtner CR, Murakami CJ, Olsen B, Kennedy BK, Kaeberlein M. A genomic analysis of chronological longevity factors in budding yeast. Cell Cycle 2011; 10:1385-96. [PMID: 21447998 DOI: 10.4161/cc.10.9.15464] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Chronological life span (CLS) has been studied as an aging paradigm in yeast. A few conserved aging genes have been identified that modulate both chronological and replicative longevity in yeast as well as longevity in the nematode Caenorhabditis elegans; however, a comprehensive analysis of the relationship between genetic control of chronological longevity and aging in other model systems has yet to be reported. To address this question, we performed a functional genomic analysis of chronological longevity for 550 single-gene deletion strains, which accounts for approximately 12% of the viable homozygous diploid deletion strains in the yeast ORF deletion collection. This study identified 33 previously unknown determinants of CLS. We found no significant enrichment for enhanced CLS among deletions corresponding to yeast orthologs of worm aging genes or among replicatively long-lived deletion strains, although a trend toward overlap was noted. In contrast, a subset of gene deletions identified from a screen for reduced acidification of culture media during growth to stationary phase was enriched for increased CLS. These results suggest that genetic control of CLS under the most commonly utilized assay conditions does not strongly overlap with longevity determinants in C. elegans, with the existing confined to a small number of genetic pathways. These data also further support the model that acidification of the culture medium plays an important role in survival during chronological aging in synthetic medium, and suggest that chronological aging studies using alternate medium conditions may be more informative with regard to aging of multicellular eukaryotes.
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Olsen B, Murakami CJ, Kaeberlein M. YODA: software to facilitate high-throughput analysis of chronological life span, growth rate, and survival in budding yeast. BMC Bioinformatics 2010; 11:141. [PMID: 20298554 PMCID: PMC2850362 DOI: 10.1186/1471-2105-11-141] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 03/18/2010] [Indexed: 11/13/2022] Open
Abstract
Background The budding yeast Saccharomyces cerevisiae is one of the most widely studied model organisms in aging-related science. Although several genetic modifiers of yeast longevity have been identified, the utility of this system for longevity studies has been limited by a lack of high-throughput assays for quantitatively measuring survival of individual yeast cells during aging. Results Here we describe the Yeast Outgrowth Data Analyzer (YODA), an automated system for analyzing population survival of yeast cells based on the kinetics of outgrowth measured by optical density over time. YODA has been designed specifically for quantification of yeast chronological life span, but can also be used to quantify growth rate and survival of yeast cells in response to a variety of different conditions, including temperature, nutritional composition of the growth media, and chemical treatments. YODA is optimized for use with a Bioscreen C MBR shaker/incubator/plate reader, but is also amenable to use with any standard plate reader or spectrophotometer. Conclusions We estimate that use of YODA as described here reduces the effort and resources required to measure chronological life span and analyze the resulting data by at least 15-fold.
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Affiliation(s)
- Brady Olsen
- Department of Pathology, University of Washington, Seattle, WA 98195, USA
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