1
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Mathisen AF, Legøy TA, Larsen U, Unger L, Abadpour S, Paulo JA, Scholz H, Ghila L, Chera S. The age-dependent regulation of pancreatic islet landscape is fueled by a HNF1a-immune signaling loop. Mech Ageing Dev 2024; 220:111951. [PMID: 38825059 DOI: 10.1016/j.mad.2024.111951] [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: 01/09/2024] [Revised: 04/30/2024] [Accepted: 05/21/2024] [Indexed: 06/04/2024]
Abstract
Animal longevity is a function of global vital organ functionality and, consequently, a complex polygenic trait. Yet, monogenic regulators controlling overall or organ-specific ageing exist, owing their conservation to their function in growth and development. Here, by using pathway analysis combined with wet-biology methods on several dynamic timelines, we identified Hnf1a as a novel master regulator of the maturation and ageing in the adult pancreatic islet during the first year of life. Conditional transgenic mice bearing suboptimal levels of this transcription factor in the pancreatic islets displayed age-dependent changes, with a profile echoing precocious maturation. Additionally, the comparative pathway analysis revealed a link between Hnf1a age-dependent regulation and immune signaling, which was confirmed in the ageing timeline of an overly immunodeficient mouse model. Last, the global proteome analysis of human islets spanning three decades of life largely backed the age-specific regulation observed in mice. Collectively, our results suggest a novel role of Hnf1a as a monogenic regulator of the maturation and ageing process in the pancreatic islet via a direct or indirect regulatory loop with immune signaling.
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Affiliation(s)
- Andreas Frøslev Mathisen
- Mohn Research Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Thomas Aga Legøy
- Mohn Research Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Ulrik Larsen
- Mohn Research Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Lucas Unger
- Mohn Research Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Shadab Abadpour
- Hybrid Technology Hub-Centre of Excellence, Faculty of Medicine, University of Oslo, Norway; Institute for Surgical Research, Department of Transplant Medicine, Oslo University Hospital, Oslo, Norway
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Hanne Scholz
- Hybrid Technology Hub-Centre of Excellence, Faculty of Medicine, University of Oslo, Norway; Institute for Surgical Research, Department of Transplant Medicine, Oslo University Hospital, Oslo, Norway
| | - Luiza Ghila
- Mohn Research Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Simona Chera
- Mohn Research Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway.
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2
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Tartiere AG, Freije JMP, López-Otín C. The hallmarks of aging as a conceptual framework for health and longevity research. FRONTIERS IN AGING 2024; 5:1334261. [PMID: 38292053 PMCID: PMC10824251 DOI: 10.3389/fragi.2024.1334261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/03/2024] [Indexed: 02/01/2024]
Abstract
The inexorability of the aging process has sparked the curiosity of human beings since ancient times. However, despite this interest and the extraordinary scientific advances in the field, the complexity of the process has hampered its comprehension. In this context, The Hallmarks of Aging were defined in 2013 with the aim of establishing an organized, systematic and integrative view of this topic, which would serve as a conceptual framework for aging research. Ten years later and promoted by the progress in the area, an updated version included three new hallmarks while maintaining the original scope. The aim of this review is to determine to what extent The Hallmarks of Aging achieved the purpose that gave rise to them. For this aim, we have reviewed the literature citing any of the two versions of The Hallmarks of Aging and conclude that they have served as a conceptual framework not only for aging research but also for related areas of knowledge. Finally, this review discusses the new candidates to become part of the Hallmarks list, analyzing the evidence that supports whether they should or should not be incorporated.
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Affiliation(s)
- Antonio G. Tartiere
- Departamento de Bioquímica y Biología Molecular, Instituto Universitario de Oncología (IUOPA), Universidad de Oviedo, Oviedo, Spain
| | - José M. P. Freije
- Departamento de Bioquímica y Biología Molecular, Instituto Universitario de Oncología (IUOPA), Universidad de Oviedo, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Carlos López-Otín
- Departamento de Bioquímica y Biología Molecular, Instituto Universitario de Oncología (IUOPA), Universidad de Oviedo, Oviedo, Spain
- Facultad de Ciencias de la Vida y la Naturaleza, Universidad Nebrija, Madrid, Spain
- Centre de Recherche des Cordeliers, Universite de Paris Cite, Sorbonne Universite, INSERM, Paris, France
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3
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Stolovich-Rain M, Fridlich O, Azulai S, Klochendler A, Anzi S, Magenheim J, Stein I, Mushasha F, Glaser B, Pikarsky E, Ben-Zvi D, Dor Y. Extensive elimination of acinar cells during normal postnatal pancreas growth. Cell Rep 2023; 42:113457. [PMID: 37995187 DOI: 10.1016/j.celrep.2023.113457] [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: 09/26/2022] [Revised: 09/01/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
While programmed cell death plays important roles during morphogenetic stages of development, post-differentiation organ growth is considered an efficient process whereby cell proliferation increases cell number. Here we demonstrate that early postnatal growth of the pancreas unexpectedly involves massive acinar cell elimination. Measurements of cell proliferation and death in the human pancreas in comparison to the actual increase in cell number predict daily elimination of 0.7% of cells, offsetting 88% of cell formation over the first year of life. Using mouse models, we show that death is associated with mitosis, through a failure of dividing cells to generate two viable daughters. In p53-deficient mice, acinar cell death and proliferation are reduced, while organ size is normal, suggesting that p53-dependent developmental apoptosis triggers compensatory proliferation. We propose that excess cell turnover during growth of the pancreas, and presumably other organs, facilitates robustness to perturbations and supports maintenance of tissue architecture.
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Affiliation(s)
- Miri Stolovich-Rain
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ori Fridlich
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Shira Azulai
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Agnes Klochendler
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Shira Anzi
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Judith Magenheim
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ilan Stein
- The Concern Foundation Laboratories at The Lautenberg Center for Immunology and Cancer Research, Israel-Canada Medical Research Institute, Faculty of Medicine, The Hebrew University, Jerusalem, Israel; Department of Pathology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Fatima Mushasha
- The Concern Foundation Laboratories at The Lautenberg Center for Immunology and Cancer Research, Israel-Canada Medical Research Institute, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Eli Pikarsky
- The Concern Foundation Laboratories at The Lautenberg Center for Immunology and Cancer Research, Israel-Canada Medical Research Institute, Faculty of Medicine, The Hebrew University, Jerusalem, Israel; Department of Pathology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Danny Ben-Zvi
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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4
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Moir RD, Merheb E, Chitu V, Richard Stanley E, Willis IM. Molecular basis of neurodegeneration in a mouse model of Polr3-related disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.571310. [PMID: 38168294 PMCID: PMC10760057 DOI: 10.1101/2023.12.12.571310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Pathogenic variants in subunits of RNA polymerase (Pol) III cause a spectrum of neurodegenerative diseases including 4H leukodystrophy. Disease onset occurs from infancy to early adulthood and is associated with a variable range and severity of neurological and non-neurological features. The molecular basis of disease pathogenesis is unknown. We developed a postnatal whole-body mouse model expressing pathogenic Polr3a mutations to examine the molecular mechanisms by which reduced Pol III transcription results primarily in central nervous system phenotypes. Polr3a mutant mice exhibit behavioral deficits, cerebral pathology and exocrine pancreatic atrophy. Transcriptome and immunohistochemistry analyses of cerebra during disease progression show a reduction in most Pol III transcripts, induction of innate immune and integrated stress responses and cell type-specific gene expression changes reflecting neuron and oligodendrocyte loss and microglial activation. Earlier in the disease when integrated stress and innate immune responses are minimally induced, mature tRNA sequencing revealed a global reduction in tRNA levels and an altered tRNA profile but no changes in other Pol III transcripts. Thus, changes in the size and/or composition of the tRNA pool have a causal role in disease initiation. Our findings reveal different tissue- and brain region-specific sensitivities to a defect in Pol III transcription.
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Affiliation(s)
- Robyn D. Moir
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx NY 10461, USA
| | - Emilio Merheb
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx NY 10461, USA
| | - Violeta Chitu
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx NY 10461, USA
| | - E. Richard Stanley
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx NY 10461, USA
| | - Ian M. Willis
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx NY 10461, USA
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx NY 10461, USA
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5
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Vittoria MA, Quinton RJ, Ganem NJ. Whole-genome doubling in tissues and tumors. Trends Genet 2023; 39:954-967. [PMID: 37714734 PMCID: PMC10840902 DOI: 10.1016/j.tig.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/19/2023] [Accepted: 08/21/2023] [Indexed: 09/17/2023]
Abstract
The overwhelming majority of proliferating somatic human cells are diploid, and this genomic state is typically maintained across successive cell divisions. However, failures in cell division can induce a whole-genome doubling (WGD) event, in which diploid cells transition to a tetraploid state. While some WGDs are developmentally programmed to produce nonproliferative tetraploid cells with specific cellular functions, unscheduled WGDs can be catastrophic: erroneously arising tetraploid cells are ill-equipped to cope with their doubled cellular and chromosomal content and quickly become genomically unstable and tumorigenic. Deciphering the genetics that underlie the genesis, physiology, and evolution of whole-genome doubled (WGD+) cells may therefore reveal therapeutic avenues to selectively eliminate pathological WGD+ cells.
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Affiliation(s)
- Marc A Vittoria
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA.
| | - Ryan J Quinton
- Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Neil J Ganem
- Department of Medicine, Division of Hematology and Oncology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA; Department of Pharmacology, Physiology, and Biophysics, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA.
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6
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Chevalier RL. Why is chronic kidney disease progressive? Evolutionary adaptations and maladaptations. Am J Physiol Renal Physiol 2023; 325:F595-F617. [PMID: 37675460 DOI: 10.1152/ajprenal.00134.2023] [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: 05/19/2023] [Revised: 08/08/2023] [Accepted: 08/27/2023] [Indexed: 09/08/2023] Open
Abstract
Despite significant advances in renal physiology, the global prevalence of chronic kidney disease (CKD) continues to increase. The emergence of multicellular organisms gave rise to increasing complexity of life resulting in trade-offs reflecting ancestral adaptations to changing environments. Three evolutionary traits shape CKD over the lifespan: 1) variation in nephron number at birth, 2) progressive nephron loss with aging, and 3) adaptive kidney growth in response to decreased nephron number. Although providing plasticity in adaptation to changing environments, the cell cycle must function within constraints dictated by available energy. Prioritized allocation of energy available through the placenta can restrict fetal nephrogenesis, a risk factor for CKD. Moreover, nephron loss with aging is a consequence of cell senescence, a pathway accelerated by adaptive nephron hypertrophy that maintains metabolic homeostasis at the expense of increased vulnerability to stressors. Driven by reproductive fitness, natural selection operates in early life but diminishes thereafter, leading to an exponential increase in CKD with aging, a product of antagonistic pleiotropy. A deeper understanding of the evolutionary constraints on the cell cycle may lead to manipulation of the balance between progenitor cell renewal and differentiation, regulation of cell senescence, and modulation of the balance between cell proliferation and hypertrophy. Application of an evolutionary perspective may enhance understanding of adaptation and maladaptation by nephrons in the progression of CKD, leading to new therapeutic advances.
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Affiliation(s)
- Robert L Chevalier
- Department of Pediatrics, The University of Virginia, Charlottesville, Virginia, United States
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7
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Khang A, Nguyen Q, Feng X, Howsmon DP, Sacks MS. Three-dimensional analysis of hydrogel-imbedded aortic valve interstitial cell shape and its relation to contractile behavior. Acta Biomater 2023; 163:194-209. [PMID: 35085795 PMCID: PMC9309197 DOI: 10.1016/j.actbio.2022.01.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 12/31/2022]
Abstract
Cell-shape is a conglomerate of mechanical, chemical, and biological mechanisms that reflects the cell biophysical state. In a specific application, we consider aortic valve interstitial cells (AVICs), which maintain the structure and function of aortic heart valve leaflets. Actomyosin stress fibers help determine AVIC shape and facilitate processes such as adhesion, contraction, and mechanosensing. However, detailed 3D assessment of stress fiber architecture and function is currently impractical. Herein, we assessed AVIC shape and contractile behaviors using hydrogel-based 3D traction force microscopy to intuit the orientation and behavior of AVIC stress fibers. We utilized spherical harmonics (SPHARM) to quantify AVIC geometries through three days of incubation, which demonstrated a shift from a spherical shape to forming substantial protrusions. Furthermore, we assessed changes in post-three day AVIC shape and contractile function within two testing regimes: (1) normal contractile level to relaxation (cytochalasin D), and (2) normal contractile level to hyper-contraction (endothelin-1). In both scenarios, AVICs underwent isovolumic shape changes and produced complex displacement fields within the hydrogel. AVICs were more elongated when relaxed and more spherical in hyper-contraction. Locally, AVIC protrusions contracted along their long axis and expanded in their circumferential direction, indicating predominately axially aligned stress fibers. Furthermore, the magnitude of protrusion displacements was correlated with protrusion length and approached a consistent displacement plateau at a similar critical length across all AVICs. This implied that stress fiber behavior is conserved, despite great variations in AVIC shapes. We anticipate our findings will bolster future investigations into AVIC stress fiber architecture and function. STATEMENT OF SIGNIFICANCE: Within the aortic valve there exists a population of aortic valve interstitial cells, which orchestrate the turnover, secretion, and remodeling of its extracellular matrix, maintaining tissue integrity and ultimately sustaining the proper mechanical function. Alterations in these processes are thought to underlie diseases of the aortic valve, which affect hundreds of thousands domestically and world-wide. Yet, to date, there are no non-surgical treatments for aortic heart valve disease, in part due to our limited understanding of the underlying disease processes. In the present study, we built upon our previous study to include a full 3D analysis of aortic valve interstitial cell shapes at differing contractile levels. The resulting detailed shape and deformation analysis provided insight into the underlying stress-fiber structures and mechanical behaviors.
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Affiliation(s)
- Alex Khang
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712-1229, USA
| | - Quan Nguyen
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712-1229, USA
| | - Xinzeng Feng
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712-1229, USA
| | - Daniel P Howsmon
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712-1229, USA
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences and the Department of Biomedical Engineering, The University of Texas at Austin, 201 East 24th St, Stop C0200, Austin, TX 78712-1229, USA.
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8
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Davies DM, van den Handel K, Bharadwaj S, Lengefeld J. Cellular enlargement - A new hallmark of aging? Front Cell Dev Biol 2022; 10:1036602. [PMID: 36438561 PMCID: PMC9688412 DOI: 10.3389/fcell.2022.1036602] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 10/17/2022] [Indexed: 12/03/2023] Open
Abstract
Years of important research has revealed that cells heavily invest in regulating their size. Nevertheless, it has remained unclear why accurate size control is so important. Our recent study using hematopoietic stem cells (HSCs) in vivo indicates that cellular enlargement is causally associated with aging. Here, we present an overview of these findings and their implications. Furthermore, we performed a broad literature analysis to evaluate the potential of cellular enlargement as a new aging hallmark and to examine its connection to previously described aging hallmarks. Finally, we highlight interesting work presenting a correlation between cell size and age-related diseases. Taken together, we found mounting evidence linking cellular enlargement to aging and age-related diseases. Therefore, we encourage researchers from seemingly unrelated areas to take a fresh look at their data from the perspective of cell size.
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Affiliation(s)
- Daniel M. Davies
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Kim van den Handel
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Soham Bharadwaj
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Jette Lengefeld
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
- Center for Hematology and Regenerative Medicine, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
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9
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Liu S, Tan C, Tyers M, Zetterberg A, Kafri R. What programs the size of animal cells? Front Cell Dev Biol 2022; 10:949382. [PMID: 36393871 PMCID: PMC9665425 DOI: 10.3389/fcell.2022.949382] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/07/2022] [Indexed: 01/19/2023] Open
Abstract
The human body is programmed with definite quantities, magnitudes, and proportions. At the microscopic level, such definite sizes manifest in individual cells - different cell types are characterized by distinct cell sizes whereas cells of the same type are highly uniform in size. How do cells in a population maintain uniformity in cell size, and how are changes in target size programmed? A convergence of recent and historical studies suggest - just as a thermostat maintains room temperature - the size of proliferating animal cells is similarly maintained by homeostatic mechanisms. In this review, we first summarize old and new literature on the existence of cell size checkpoints, then discuss additional advances in the study of size homeostasis that involve feedback regulation of cellular growth rate. We further discuss recent progress on the molecules that underlie cell size checkpoints and mechanisms that specify target size setpoints. Lastly, we discuss a less-well explored teleological question: why does cell size matter and what is the functional importance of cell size control?
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Affiliation(s)
- Shixuan Liu
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada,Program in Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada,Department of Chemical and Systems Biology, Stanford University, Stanford, CA, United States,*Correspondence: Shixuan Liu, ; Ran Kafri,
| | - Ceryl Tan
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada,Program in Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Mike Tyers
- Institute for Research in Immunology and Cancer, University of Montréal, Montréal, QC, Canada
| | - Anders Zetterberg
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Ran Kafri
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada,Program in Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada,*Correspondence: Shixuan Liu, ; Ran Kafri,
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10
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Abderrahmani A, Jacovetti C, Regazzi R. Lessons from neonatal β-cell epigenomic for diabetes prevention and treatment. Trends Endocrinol Metab 2022; 33:378-389. [PMID: 35382967 DOI: 10.1016/j.tem.2022.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/08/2022] [Accepted: 03/10/2022] [Indexed: 12/30/2022]
Abstract
Pancreatic β-cell expansion and functional maturation during the birth-to-weaning period plays an essential role in the adaptation of plasma insulin levels to metabolic needs. These events are driven by epigenetic programs triggered by growth factors, hormones, and nutrients. These mechanisms operating in the neonatal period can be at least in part reactivated in adult life to increase the functional β-cell mass and face conditions of increased insulin demand such as obesity or pregnancy. In this review, we will highlight the importance of studying these signaling pathways and epigenetic programs to understand the causes of different forms of diabetes and to permit the design of novel therapeutic strategies to prevent and treat this metabolic disorder affecting hundreds of millions of people worldwide.
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Affiliation(s)
- Amar Abderrahmani
- Universitéde Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France.
| | - Cécile Jacovetti
- Department of Fundamental Neuroscience, University of Lausanne, 1005 Lausanne, Switzerland
| | - Romano Regazzi
- Department of Fundamental Neuroscience, University of Lausanne, 1005 Lausanne, Switzerland; Department of Biomedical Science, University of Lausanne, 1005 Lausanne, Switzerland.
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11
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Garcia DM, Campbell EA, Jakobson CM, Tsuchiya M, Shaw EA, DiNardo AL, Kaeberlein M, Jarosz DF. A prion accelerates proliferation at the expense of lifespan. eLife 2021; 10:e60917. [PMID: 34545808 PMCID: PMC8455135 DOI: 10.7554/elife.60917] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 08/12/2021] [Indexed: 12/23/2022] Open
Abstract
In fluctuating environments, switching between different growth strategies, such as those affecting cell size and proliferation, can be advantageous to an organism. Trade-offs arise, however. Mechanisms that aberrantly increase cell size or proliferation-such as mutations or chemicals that interfere with growth regulatory pathways-can also shorten lifespan. Here we report a natural example of how the interplay between growth and lifespan can be epigenetically controlled. We find that a highly conserved RNA-modifying enzyme, the pseudouridine synthase Pus4/TruB, can act as a prion, endowing yeast with greater proliferation rates at the cost of a shortened lifespan. Cells harboring the prion grow larger and exhibit altered protein synthesis. This epigenetic state, [BIG+] (better in growth), allows cells to heritably yet reversibly alter their translational program, leading to the differential synthesis of dozens of proteins, including many that regulate proliferation and aging. Our data reveal a new role for prion-based control of an RNA-modifying enzyme in driving heritable epigenetic states that transform cell growth and survival.
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Affiliation(s)
- David M Garcia
- Department of Chemical & Systems Biology, Stanford University School of Medicine, Stanford, United States
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, United States
| | - Edgar A Campbell
- Department of Chemical & Systems Biology, Stanford University School of Medicine, Stanford, United States
| | - Christopher M Jakobson
- Department of Chemical & Systems Biology, Stanford University School of Medicine, Stanford, United States
| | - Mitsuhiro Tsuchiya
- Department of Pathology, University of Washington, Seattle, United States
| | - Ethan A Shaw
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, United States
| | - Acadia L DiNardo
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, United States
| | - Matt Kaeberlein
- Department of Pathology, University of Washington, Seattle, United States
| | - Daniel F Jarosz
- Department of Chemical & Systems Biology, Stanford University School of Medicine, Stanford, United States
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, United States
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12
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Karin O, Raz M, Tendler A, Bar A, Korem Kohanim Y, Milo T, Alon U. A new model for the HPA axis explains dysregulation of stress hormones on the timescale of weeks. Mol Syst Biol 2021; 16:e9510. [PMID: 32672906 PMCID: PMC7364861 DOI: 10.15252/msb.20209510] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 12/29/2022] Open
Abstract
Stress activates a complex network of hormones known as the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis is dysregulated in chronic stress and psychiatric disorders, but the origin of this dysregulation is unclear and cannot be explained by current HPA models. To address this, we developed a mathematical model for the HPA axis that incorporates changes in the total functional mass of the HPA hormone-secreting glands. The mass changes are caused by HPA hormones which act as growth factors for the glands in the axis. We find that the HPA axis shows the property of dynamical compensation, where gland masses adjust over weeks to buffer variation in physiological parameters. These mass changes explain the experimental findings on dysregulation of cortisol and ACTH dynamics in alcoholism, anorexia, and postpartum. Dysregulation occurs for a wide range of parameters and is exacerbated by impaired glucocorticoid receptor (GR) feedback, providing an explanation for the implication of GR in mood disorders. These findings suggest that gland-mass dynamics may play an important role in the pathophysiology of stress-related disorders.
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Affiliation(s)
- Omer Karin
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Moriya Raz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Avichai Tendler
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Alon Bar
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yael Korem Kohanim
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Tomer Milo
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Uri Alon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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13
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Tan C, Ginzberg MB, Webster R, Iyengar S, Liu S, Papadopoli D, Concannon J, Wang Y, Auld DS, Jenkins JL, Rost H, Topisirovic I, Hilfinger A, Derry WB, Patel N, Kafri R. Cell size homeostasis is maintained by CDK4-dependent activation of p38 MAPK. Dev Cell 2021; 56:1756-1769.e7. [PMID: 34022133 DOI: 10.1016/j.devcel.2021.04.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 02/08/2021] [Accepted: 04/28/2021] [Indexed: 02/07/2023]
Abstract
While molecules that promote the growth of animal cells have been identified, it remains unclear how such signals are orchestrated to determine a characteristic target size for different cell types. It is increasingly clear that cell size is determined by size checkpoints-mechanisms that restrict the cell cycle progression of cells that are smaller than their target size. Previously, we described a p38 MAPK-dependent cell size checkpoint mechanism whereby p38 is selectively activated and prevents cell cycle progression in cells that are smaller than a given target size. In this study, we show that the specific target size required for inactivation of p38 and transition through the cell cycle is determined by CDK4 activity. Our data suggest a model whereby p38 and CDK4 cooperate analogously to the function of a thermostat: while p38 senses irregularities in size, CDK4 corresponds to the thermostat dial that sets the target size.
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Affiliation(s)
- Ceryl Tan
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Miriam B Ginzberg
- Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Rachel Webster
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Seshu Iyengar
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, ON L5L 1C6, Canada
| | - Shixuan Liu
- Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - David Papadopoli
- Gerald Bronfman Department of Oncology and Lady Davis Institute, McGill University Montreal, QC H4A 3T2, Canada
| | - John Concannon
- Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Yuan Wang
- Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Douglas S Auld
- Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Jeremy L Jenkins
- Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Hannes Rost
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada
| | - Ivan Topisirovic
- Gerald Bronfman Department of Oncology and Lady Davis Institute, McGill University Montreal, QC H4A 3T2, Canada
| | - Andreas Hilfinger
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, ON L5L 1C6, Canada
| | - W Brent Derry
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Nish Patel
- Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Ran Kafri
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.
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14
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Image-Based Machine Learning Algorithms for Disease Characterization in the Human Type 1 Diabetes Pancreas. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 191:454-462. [PMID: 33307036 DOI: 10.1016/j.ajpath.2020.11.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 11/12/2020] [Accepted: 11/24/2020] [Indexed: 02/07/2023]
Abstract
Emerging data suggest that type 1 diabetes affects not only the β-cell-containing islets of Langerhans, but also the surrounding exocrine compartment. Using digital pathology, machine learning algorithms were applied to high-resolution, whole-slide images of human pancreata to determine whether the tissue composition in individuals with or at risk for type 1 diabetes differs from those without diabetes. Transplant-grade pancreata from organ donors were evaluated from 16 nondiabetic autoantibody-negative controls, 8 nondiabetic autoantibody-positive subjects with increased type 1 diabetes risk, and 19 persons with type 1 diabetes (0 to 12 years' duration). HALO image analysis algorithms were implemented to compare architecture of the main pancreatic duct as well as cell size, density, and area of acinar, endocrine, ductal, and other nonendocrine, nonexocrine tissues. Type 1 diabetes was found to affect exocrine area, acinar cell density, and size, whereas the type of difference correlated with the presence or absence of insulin-positive cells remaining in the pancreas. These changes were not observed before disease onset, as indicated by modeling cross-sectional data from pancreata of autoantibody-positive subjects and those diagnosed with type 1 diabetes. These data provide novel insights into anatomic differences in type 1 diabetes pancreata and demonstrate that machine learning can be adapted for the evaluation of disease processes from cross-sectional data sets.
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15
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Reproductive Potential of Yeast Cells Depends on Overall Action of Interconnected Changes in Central Carbon Metabolism, Cellular Biosynthetic Capacity, and Proteostasis. Int J Mol Sci 2020; 21:ijms21197313. [PMID: 33022992 PMCID: PMC7582853 DOI: 10.3390/ijms21197313] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/18/2022] Open
Abstract
Carbon metabolism is a crucial aspect of cell life. Glucose, as the primary source of energy and carbon skeleton, determines the type of cell metabolism and biosynthetic capabilities, which, through the regulation of cell size, may affect the reproductive capacity of the yeast cell. Calorie restriction is considered as the most effective way to improve cellular physiological capacity, and its molecular mechanisms are complex and include several nutrient signaling pathways. It is widely assumed that the metabolic shift from fermentation to respiration is treated as a substantial driving force for the mechanism of calorie restriction and its influence on reproductive capabilities of cells. In this paper, we propose another approach to this issue based on analysis the connection between energy-producing and biomass formation pathways which are closed in the metabolic triangle, i.e., the respiration-glycolysis-pentose phosphate pathway. The analyses were based on the use of cells lacking hexokinase 2 (∆hxk2) and conditions of different glucose concentration corresponding to the calorie restriction and the calorie excess. Hexokinase 2 is the key enzyme involved in central carbon metabolism and is also treated as a calorie restriction mimetic. The experimental model used allows us to explain both the role of increased respiration as an effect of calorie restriction but also other aspects of carbon metabolism and the related metabolic flux in regulation of reproductive potential of the cells. The obtained results reveal that increased respiration is not a prerequisite for reproductive potential extension but rather an accompanying effect of the positive role of calorie restriction. More important seems to be the changes connected with fluxes in central carbon metabolic pathways resulting in low biosynthetic capabilities and improved proteostasis.
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16
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Egozi A, Bahar Halpern K, Farack L, Rotem H, Itzkovitz S. Zonation of Pancreatic Acinar Cells in Diabetic Mice. Cell Rep 2020; 32:108043. [PMID: 32814046 PMCID: PMC7443616 DOI: 10.1016/j.celrep.2020.108043] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/02/2020] [Accepted: 07/24/2020] [Indexed: 12/25/2022] Open
Abstract
The islets of Langerhans are dynamic structures that can change in size, number of cells, and molecular function in response to physiological and pathological stress. Molecular cues originating from the surrounding "peri-islet" acinar cells that could facilitate this plasticity have not been explored. Here, we combine single-molecule transcript imaging in the intact pancreas and transcriptomics to identify spatial heterogeneity of acinar cell gene expression. We find that peri-islet acinar cells exhibit a distinct molecular signature in db/db diabetic mice that includes upregulation of trypsin family genes and elevated mTOR activity. This zonated expression program seems to be induced by CCK that is secreted from islet cells. Elevated peri-islet trypsin secretion could facilitate the islet expansion observed in this model via modulation of the islet capsule matrix components. Our study highlights a molecular axis of communication between the pancreatic exocrine and endocrine compartments that may be relevant to islet expansion.
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Affiliation(s)
- Adi Egozi
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Keren Bahar Halpern
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Lydia Farack
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Hagar Rotem
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Shalev Itzkovitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
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17
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Abstract
Polyploidy (or whole-genome duplication) is the condition of having more than two basic sets of chromosomes. Polyploidization is well tolerated in many species and can lead to specific biological functions. In mammals, programmed polyploidization takes place during development in certain tissues, such as the heart and placenta, and is considered a feature of differentiation. However, unscheduled polyploidization can cause genomic instability and has been observed in pathological conditions, such as cancer. Polyploidy of the liver parenchyma was first described more than 100 years ago. The liver is one of the few mammalian organs that display changes in polyploidy during homeostasis, regeneration and in response to damage. In the human liver, approximately 30% of hepatocytes are polyploid. The polyploidy of hepatocytes results from both nuclear polyploidy (an increase in the amount of DNA per nucleus) and cellular polyploidy (an increase in the number of nuclei per cell). In this Review, we discuss the regulation of polyploidy in liver development and pathophysiology. We also provide an overview of current knowledge about the mechanisms of hepatocyte polyploidization, its biological importance and the fate of polyploid hepatocytes during liver tumorigenesis.
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18
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Low steady-state oxidative stress inhibits adipogenesis by altering mitochondrial dynamics and decreasing cellular respiration. Redox Biol 2020; 32:101507. [PMID: 32208164 PMCID: PMC7097524 DOI: 10.1016/j.redox.2020.101507] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/04/2020] [Accepted: 03/13/2020] [Indexed: 12/11/2022] Open
Abstract
Adipogenesis is a fundamental process of white adipose tissue function, supporting lipid storage and release, while avoiding its spillover and ectopic accumulation in tissues and organs. During aging adipogenesis is impaired and among other factors, oxidative stress contributes to this process. Adipogenesis requires functional and dynamic mitochondria; however, this organelle itself becomes dysfunctional during aging and accounts for most of reactive oxygen species (ROS) production. Here, we evaluated whether oxidative stress impairs adipogenesis through functional impairment of mitodynamics by utilizing hyperoxia as a continuous source of oxidative stress while maintaining cellular viability. This negatively impacted mitochondrial function, including respiration and dynamics and ultimately blocked adipogenesis. Interestingly, this state was reversible by using the antidiabetic drug, Rosiglitazone, which reduced oxidative stress, restored mitochondrial dynamics and respiration and augmented adipogenesis. Moreover, in vitro results were in agreement with in vivo models of oxidative stress and aging, in which mice depleted of the superoxide dismutase enzyme 1 (SOD1) and old wild-type C57BL/6JRj mice demonstrated the same trend of adipogenic potential. Importantly, in humans the results follow the same pattern, showing a downregulation of adipogenic markers during aging. Since the levels of oxidative stress and peripheral insulin resistance increase with age, while adipogenesis decreases during aging, our model helps to understand a possible way to overcome physiologically low, steady stress conditions and restore adipogenesis, avoiding accumulation of deleterious hypertrophic adipocytes in favor of beneficial hyperplasia.
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19
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Mugahid D, Kalocsay M, Liu X, Gruver JS, Peshkin L, Kirschner MW. YAP regulates cell size and growth dynamics via non-cell autonomous mediators. eLife 2020; 9:53404. [PMID: 31913124 PMCID: PMC6989120 DOI: 10.7554/elife.53404] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 12/16/2019] [Indexed: 12/18/2022] Open
Abstract
The Hippo pathway regulates organ size, regeneration, and cell growth by controlling the stability of the transcription factor, YAP (Yorkie in Drosophila). When there is tissue damage, YAP is activated allowing the restoration of homeostatic tissue size. The exact signals by which YAP is activated are still not fully understood, but its activation is known to affect both cell size and cell number. Here we used cultured cells to examine the coordinated regulation of cell size and number under the control of YAP. Our experiments in isogenic HEK293 cells reveal that YAP can affect cell size and number by independent circuits. Some of these effects are cell autonomous, such as proliferation, while others are mediated by secreted signals. In particular CYR61, a known secreted YAP target, is a non-cell autonomous mediator of cell survival, while another unidentified secreted factor controls cell size.
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Affiliation(s)
- Douaa Mugahid
- Department of Systems Biology, Harvard Medical School, Boston, United States
| | - Marian Kalocsay
- Department of Systems Biology, Harvard Medical School, Boston, United States
| | - Xili Liu
- Department of Systems Biology, Harvard Medical School, Boston, United States
| | | | - Leonid Peshkin
- Department of Systems Biology, Harvard Medical School, Boston, United States
| | - Marc W Kirschner
- Department of Systems Biology, Harvard Medical School, Boston, United States
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20
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Jaafar R, Tran S, Shah AN, Sun G, Valdearcos M, Marchetti P, Masini M, Swisa A, Giacometti S, Bernal-Mizrachi E, Matveyenko A, Hebrok M, Dor Y, Rutter GA, Koliwad SK, Bhushan A. mTORC1 to AMPK switching underlies β-cell metabolic plasticity during maturation and diabetes. J Clin Invest 2019; 129:4124-4137. [PMID: 31265435 PMCID: PMC6763225 DOI: 10.1172/jci127021] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 06/24/2019] [Indexed: 12/28/2022] Open
Abstract
Pancreatic beta cells (β-cells) differentiate during fetal life, but only postnatally acquire the capacity for glucose-stimulated insulin secretion (GSIS). How this happens is not clear. In exploring what molecular mechanisms drive the maturation of β-cell function, we found that the control of cellular signaling in β-cells fundamentally switched from the nutrient sensor target of rapamycin (mTORC1) to the energy sensor 5'-adenosine monophosphate-activated protein kinase (AMPK), and that this was critical for functional maturation. Moreover, AMPK was activated by the dietary transition taking place during weaning, and this in turn inhibited mTORC1 activity to drive the adult β-cell phenotype. While forcing constitutive mTORC1 signaling in adult β-cells relegated them to a functionally immature phenotype with characteristic transcriptional and metabolic profiles, engineering the switch from mTORC1 to AMPK signaling was sufficient to promote β-cell mitochondrial biogenesis, a shift to oxidative metabolism, and functional maturation. We also found that type 2 diabetes, a condition marked by both mitochondrial degeneration and dysregulated GSIS, was associated with a remarkable reversion of the normal AMPK-dependent adult β-cell signature to a more neonatal one characterized by mTORC1 activation. Manipulating the way in which cellular nutrient signaling pathways regulate β-cell metabolism may thus offer new targets to improve β-cell function in diabetes.
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Affiliation(s)
- Rami Jaafar
- The Diabetes Center, UCSF, San Francisco, California, USA
| | - Stella Tran
- The Diabetes Center, UCSF, San Francisco, California, USA
| | - Ajit N. Shah
- The Diabetes Center, UCSF, San Francisco, California, USA
| | - Gao Sun
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, Hammersmith Hospital London, United Kingdom
| | | | - Piero Marchetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Matilde Masini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Avital Swisa
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | | - Ernesto Bernal-Mizrachi
- Division of Endocrinology, Diabetes and Metabolism, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Aleksey Matveyenko
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Yuval Dor
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, Hammersmith Hospital London, United Kingdom
| | | | - Anil Bhushan
- The Diabetes Center, UCSF, San Francisco, California, USA
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21
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Abstract
Individual cell types have characteristic sizes, suggesting that size sensing mechanisms may coordinate transcription, translation, and metabolism with cell growth rates. Two types of size-sensing mechanisms have been proposed: spatial sensing of the location or dimensions of a signal, subcellular structure or organelle; or titration-based sensing of the intracellular concentrations of key regulators. Here we propose that size sensing in animal cells combines both titration and spatial sensing elements in a dynamic mechanism whereby microtubule motor-dependent localization of RNA encoding importin β1 and mTOR, coupled with regulated local protein synthesis, enable cytoskeleton length sensing for cell growth regulation.
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Affiliation(s)
- Ida Rishal
- Department of Biomolecular Sciences, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Mike Fainzilber
- Department of Biomolecular Sciences, Weizmann Institute of Science, 76100, Rehovot, Israel.
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22
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Maslanka R, Zadrag-Tecza R. Less is more or more is less: Implications of glucose metabolism in the regulation of the reproductive potential and total lifespan of the Saccharomyces cerevisiae yeast. J Cell Physiol 2019; 234:17622-17638. [PMID: 30805924 DOI: 10.1002/jcp.28386] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 01/23/2019] [Accepted: 01/28/2019] [Indexed: 01/10/2023]
Abstract
Carbohydrates are dietary nutrients that have an influence on cells physiology, cell reproductive capacity and, consequently, the lifespan of organisms. They are used in cellular processes after conversion to glucose, which is the primary source of energy and carbon skeleton for biosynthetic processes. Studies of the influence of glucose on cellular parameters and lifespan of organisms are primarily concerned with the effect of low glucose concentration defined as calorie restriction conditions. However, the effect of high glucose concentration on cell physiology is also very important. Thus, a comparative analysis of the effects of low and high glucose concentration conditions on cell efficiency was proposed with regard to reproductive capacity and total lifespan of the cell. Glucose concentration determines the type of metabolism and biosynthetic capabilities, which in turn, through the regulation on the cell size, may affect the reproductive capacity of cells. This study was conducted on yeast cells of wild-type and mutant strains Δgpa2 and Δgpr1 with glucose signalling pathway impairment. Such an experimental model enabled testing both the role of glucose concentration in the regulation of metabolic changes and the extent to which these changes depend on the extracellular or intracellular glucose concentrations. It has been shown here that calorie/glucose excess connected with changes in cell metabolic fluxes increases biosynthetic capabilities of yeast cells. This leads to an increase in cell dry weight accompanied by the increase in cell size and a simultaneous decrease in the reproductive potential and the overall length of cell life.
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Affiliation(s)
- Roman Maslanka
- Department of Biochemistry and Cell Biology, Faculty of Biotechnology, University of Rzeszow, Rzeszow, Poland
| | - Renata Zadrag-Tecza
- Department of Biochemistry and Cell Biology, Faculty of Biotechnology, University of Rzeszow, Rzeszow, Poland
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23
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Bartke A, Quainoo N. Impact of Growth Hormone-Related Mutations on Mammalian Aging. Front Genet 2018; 9:586. [PMID: 30542372 PMCID: PMC6278173 DOI: 10.3389/fgene.2018.00586] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/12/2018] [Indexed: 12/21/2022] Open
Abstract
Mutations of a single gene can lead to a major increase in longevity in organisms ranging from yeast and worms to insects and mammals. Discovering these mutations (sometimes referred to as “longevity genes”) led to identification of evolutionarily conserved molecular, cellular, and organismal mechanisms of aging. Studies in mice provided evidence for the important role of growth hormone (GH) signaling in mammalian aging. Mice with mutations or gene deletions leading to GH deficiency or GH resistance have reduced body size and delayed maturation, but are healthier and more resistant to stress, age slower, and live longer than their normal (wild type) siblings. Mutations of the same genes in people can provide remarkable protection from age-related disease, but have no consistent impact on lifespan. Ongoing research indicates that genetic defects in GH signaling are linked to extension of healthspan and lifespan via a variety of interlocking mechanism, including improvements in genome and stem cell maintenance, stress resistance, glucose homeostasis, and thermogenesis, along with reductions in the mechanistic target of rapamycin (mTOR) C1 complex signaling and in chronic low grade inflammation.
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Affiliation(s)
- Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Nana Quainoo
- Department of Biology, University of Illinois Springfield, Springfield, IL, United States
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24
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Björklund M. Cell size homeostasis: Metabolic control of growth and cell division. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:409-417. [PMID: 30315834 DOI: 10.1016/j.bbamcr.2018.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/25/2018] [Accepted: 10/03/2018] [Indexed: 12/14/2022]
Abstract
Joint regulation of growth rate and cell division rate determines cell size. Here we discuss how animal cells achieve cell size homeostasis potentially involving multiple signaling pathways converging at metabolic regulation of growth rate and cell cycle progression. While several models have been developed to explain cell size control, comparison of the two predominant models shows that size homeostasis is dependent on the ability to adjust cellular growth rate based on cell size. Consequently, maintenance of size homeostasis requires that larger cells can grow slower than small cells in relative terms. We review recent experimental evidence showing that such size adjustment occurs primarily at or immediately before the G1/S transition of the cell cycle. We further propose that bidirectional feedback between growth rate and size results in cell size sensing and discuss potential mechanisms how this may be accomplished.
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Affiliation(s)
- Mikael Björklund
- Zhejiang University-University of Edinburgh (ZJU-UoE) Institute, Zhejiang University School of Medicine, International Campus, 718 East Haizhou Rd., Haining, Zhejiang 314400, PR China.
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25
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Abstract
The factors determining longevity of different animals are incompletely defined. In this issue of Developmental Cell, Anzi et al. (2018) show that distinct strategies for postnatal pancreatic growth operate in different mammals and correlate with lifespan, with short-lived species exhibiting increasing pancreatic cell size and long-lived animals increasing cell number.
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26
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Smith JT, White JW, Dungrawala H, Hua H, Schneider BL. Yeast lifespan variation correlates with cell growth and SIR2 expression. PLoS One 2018; 13:e0200275. [PMID: 29979754 PMCID: PMC6034835 DOI: 10.1371/journal.pone.0200275] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/22/2018] [Indexed: 11/19/2022] Open
Abstract
Isogenic wild type yeast cells raised in controlled environments display a significant range of lifespan variation. Recent microfluidic studies suggest that differential growth or gene expression patterns may explain some of the heterogeneity of aging assays. Herein, we sought to complement this work by similarly examining a large set of replicative lifespan data from traditional plate assays. In so doing, we reproduced the finding that short-lived cells tend to arrest at senescence with a budded morphology. Further, we found that wild type cells born unusually small did not have an extended lifespan. However, large birth size and/or high inter-generational growth rates significantly correlated with a reduced lifespan. Finally, we found that SIR2 expression levels correlated with lifespan and intergenerational growth. SIR2 expression was significantly reduced in large cells and increased in small wild type cells. A moderate increase in SIR2 expression correlated with reduced growth, decreased proliferation and increased lifespan in plate aging assays. We conclude that cellular growth rates and SIR2 expression levels may contribute to lifespan variation in individual cells.
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Affiliation(s)
- Jessica T. Smith
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
| | - Jill W. White
- Center for the Integration of STEM Education & Research, Texas Tech University, Lubbock, TX, United States of America
| | - Huzefa Dungrawala
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, United States of America
| | - Hui Hua
- Department of Medical Education, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
| | - Brandt L. Schneider
- Department of Medical Education, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
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