1
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Wang Q, Xie L, Wang Y, Jin B, Ren J, Dong Z, Chen G, Liu D. Djhsp70s, especially Djhsp70c, play a key role in planarian regeneration and tissue homeostasis by regulating cell proliferation and apoptosis. Gene 2022; 820:146215. [PMID: 35122923 DOI: 10.1016/j.gene.2022.146215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 12/13/2021] [Accepted: 01/13/2022] [Indexed: 11/28/2022]
Abstract
Heat shock protein 70 family (HSP70s) is one of the most conserved and important group of HSPs as molecular chaperones, which plays an important role in cytoprotection, anti-apoptosis and so on. However, the molecular mechanism of HSP70s in animal regeneration remains to be delineated. In this study, we investigate the roles of HSP70s in regeneration of planarian. The four genes, Djhsp70a, Djhsp70b, Djhsp70c, and Djhsp70d of the HSP70s, are selected from the transcriptome database, because of their high expression levels in planarians. We then study the biological roles of each gene by conducting various experimental techniques, including RNAi, RT-PCR, WISH, Whole-mount immunostaining and TUNEL. The results show: (1) External stressors, such as temperature, tissue damage and ionic liquid upregulate the expression of Djhsp70s significantly. (2) The gene expression of Djhsp70s in planarians exhibits dynamic patterns. According to the result of WISH, the Djhsp70s are mainly expressed in parenchymal tissues on both sides of the body as well as blastema. It is consistent with the data of qRT-PCR. (3) After RNA interference of Djhsp70s, the worms experience cephalic regression and lysis, body curling, stagnant regeneration and death. (4) Knockdown of Djhsp70s affect the cell proliferation and apoptosis. These results suggest that Djhsp70s are not only conserved in cytoprotection, but involved in homeostasis maintenance and regeneration process by regulating coordination of cell proliferation and apoptosis in planarians.
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Affiliation(s)
- Qinghua Wang
- College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
| | - Lijuan Xie
- College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
| | - Yixuan Wang
- College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
| | - Baijie Jin
- College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
| | - Jing Ren
- College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
| | - Zimei Dong
- College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
| | - Guangwen Chen
- College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
| | - Dezeng Liu
- College of Life Science, Henan Normal University, Xinxiang 453007, Henan, China.
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2
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Bohr TE, Shiroor DA, Adler CE. Planarian stem cells sense the identity of the missing pharynx to launch its targeted regeneration. eLife 2021; 10:e68830. [PMID: 34156924 PMCID: PMC8219383 DOI: 10.7554/elife.68830] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/22/2021] [Indexed: 12/25/2022] Open
Abstract
In order to regenerate tissues successfully, stem cells must detect injuries and restore missing cell types through largely unknown mechanisms. Planarian flatworms have an extensive stem cell population responsible for regenerating any organ after amputation. Here, we compare planarian stem cell responses to different injuries by either amputation of a single organ, the pharynx, or removal of tissues from other organs by decapitation. We find that planarian stem cells adopt distinct behaviors depending on what tissue is missing to target progenitor and tissue production towards missing tissues. Loss of non-pharyngeal tissues only increases non-pharyngeal progenitors, while pharynx removal selectively triggers division and expansion of pharynx progenitors. By pharmacologically inhibiting either mitosis or activation of the MAP kinase ERK, we identify a narrow window of time during which stem cell division and ERK signaling produces pharynx progenitors necessary for regeneration. These results indicate that planarian stem cells can tailor their output to match the regenerative needs of the animal.
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Affiliation(s)
- Tisha E Bohr
- Department of Molecular Medicine, Cornell University College of Veterinary MedicineIthacaUnited States
| | - Divya A Shiroor
- Department of Molecular Medicine, Cornell University College of Veterinary MedicineIthacaUnited States
| | - Carolyn E Adler
- Department of Molecular Medicine, Cornell University College of Veterinary MedicineIthacaUnited States
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3
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Ermakov AM, Ermakova ON, Popov AL, Manokhin AA, Ivanov VK. Opposite effects of low intensity light of different wavelengths on the planarian regeneration rate. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 202:111714. [PMID: 31830733 DOI: 10.1016/j.jphotobiol.2019.111714] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/11/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023]
Abstract
Planarian freshwater flatworms have the unique ability to regenerate due to stem cell activity. The process of regeneration is extremely sensitive to various factors, including light radiation. Here, the effect of low-intensity LED light of different wavelengths on regeneration, stem cell proliferation and gene expression associated with these processes was studied. LED matrices with different wavelengths (red (λmax = 635 nm), green (λmax = 520 nm) and blue (λmax = 463 nm), as well as LED laser diodes (red (λmax = 638.5 nm), green (λmax = 533 nm) and blue (λmax = 420 nm), were used in the experiments. Computer-assisted morphometry, whole-mount immunocytochemical study and RT-PCR were used to analyze the biological effects of LED light exposure on the planarian regeneration in vivo. It was found that a one-time exposure of regenerating planarians with low-intensity red light diodes stimulated head blastema growth in a dose-dependent manner (up to 40%). The green light exposure of planarians resulted in the opposite effect, showing a reduced head blastema growth rate by up to 21%. The blue light exposure did not lead to any changes in the rate of head blastema growth. The maximum effects of light exposure were observed at a dose of 175.2 mJ/cm2. No significant differences were revealed in the dynamics of neoblasts' (planarian stem cells) proliferation under red and green light exposure. However, the RT-PCR gene expression analysis of 46 wound-induced genes revealed their up-regulation upon red LED light exposure, and down-regulation upon green light exposure. Thus, we have demonstrated that the planarian regeneration process is rather sensitive to the effects of low-intensity light radiation of certain wavelengths, the biological activity of red and green light being dictated by the different expression of the genes regulating transcriptional activity.
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Affiliation(s)
- A M Ermakov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
| | - O N Ermakova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
| | - A L Popov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia
| | - A A Manokhin
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Oblast 142290, Russia
| | - V K Ivanov
- Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow 119991, Russia.
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4
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Iglesias M, Felix DA, Gutiérrez-Gutiérrez Ó, De Miguel-Bonet MDM, Sahu S, Fernández-Varas B, Perona R, Aboobaker AA, Flores I, González-Estévez C. Downregulation of mTOR Signaling Increases Stem Cell Population Telomere Length during Starvation of Immortal Planarians. Stem Cell Reports 2019; 13:405-418. [PMID: 31353226 PMCID: PMC6700675 DOI: 10.1016/j.stemcr.2019.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 06/22/2019] [Accepted: 06/24/2019] [Indexed: 12/20/2022] Open
Abstract
Reduction of caloric intake delays and prevents age-associated diseases and extends the life span in many organisms. It may be that these benefits are due to positive effects of caloric restriction on stem cell function. We use the planarian model Schmidtea mediterranea, an immortal animal that adapts to long periods of starvation by shrinking in size, to investigate the effects of starvation on telomere length. We show that the longest telomeres are a general signature of planarian adult stem cells. We also observe that starvation leads to an enrichment of stem cells with the longest telomeres and that this enrichment is dependent on mTOR signaling. We propose that one important effect of starvation for the rejuvenation of the adult stem cell pool is through increasing the median telomere length in somatic stem cells. Such a mechanism has broad implications for how dietary effects on aging are mediated at the whole-organism level.
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Affiliation(s)
- Marta Iglesias
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Beutenbergstrasse 11, 07745 Jena, Germany; Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Daniel A Felix
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Beutenbergstrasse 11, 07745 Jena, Germany
| | | | - Maria Del Mar De Miguel-Bonet
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Sounak Sahu
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - Beatriz Fernández-Varas
- Instituto de Investigaciones Biomédicas CSIC/UAM, IDiPaz, Arturo Duperier 4, 28029 Madrid, Spain
| | - Rosario Perona
- Instituto de Investigaciones Biomédicas CSIC/UAM, IDiPaz, Arturo Duperier 4, 28029 Madrid, Spain; Ciber Network on Rare Diseases (CIBERER), C/ Alvaro de Bazan, 10, 46010 Valencia, Spain
| | - A Aziz Aboobaker
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - Ignacio Flores
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro 3, 28029 Madrid, Spain.
| | - Cristina González-Estévez
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Beutenbergstrasse 11, 07745 Jena, Germany; Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro 3, 28029 Madrid, Spain.
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5
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Levin M, Pietak AM, Bischof J. Planarian regeneration as a model of anatomical homeostasis: Recent progress in biophysical and computational approaches. Semin Cell Dev Biol 2019; 87:125-144. [PMID: 29635019 PMCID: PMC6234102 DOI: 10.1016/j.semcdb.2018.04.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/03/2018] [Accepted: 04/06/2018] [Indexed: 12/22/2022]
Abstract
Planarian behavior, physiology, and pattern control offer profound lessons for regenerative medicine, evolutionary biology, morphogenetic engineering, robotics, and unconventional computation. Despite recent advances in the molecular genetics of stem cell differentiation, this model organism's remarkable anatomical homeostasis provokes us with truly fundamental puzzles about the origin of large-scale shape and its relationship to the genome. In this review article, we first highlight several deep mysteries about planarian regeneration in the context of the current paradigm in this field. We then review recent progress in understanding of the physiological control of an endogenous, bioelectric pattern memory that guides regeneration, and how modulating this memory can permanently alter the flatworm's target morphology. Finally, we focus on computational approaches that complement reductive pathway analysis with synthetic, systems-level understanding of morphological decision-making. We analyze existing models of planarian pattern control and highlight recent successes and remaining knowledge gaps in this interdisciplinary frontier field.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States; Biology Department, Tufts University, Medford, MA 02155, United States.
| | - Alexis M Pietak
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States
| | - Johanna Bischof
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States; Biology Department, Tufts University, Medford, MA 02155, United States
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6
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Tran TA, Gentile L. A lineage CLOUD for neoblasts. Semin Cell Dev Biol 2018; 87:22-29. [PMID: 29727726 DOI: 10.1016/j.semcdb.2018.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/10/2018] [Accepted: 04/25/2018] [Indexed: 12/18/2022]
Abstract
In planarians, pluripotency can be studied in vivo in the adult animal, making these animals a unique model system where pluripotency-based regeneration (PBR)-and its therapeutic potential-can be investigated. This review focuses on recent findings to build a cloud model of fate restriction likelihood for planarian stem and progenitor cells. Recently, a computational approach based on functional and molecular profiling at the single cell level was proposed for human hematopoietic stem cells. Based on data generated both in vivo and ex vivo, we hypothesized that planarian stem cells could acquire multiple direction lineage biases, following a "badlands" landscape. Instead of a discrete tree-like hierarchy, where the potency of stem/progenitor cells reduces stepwise, we propose a Continuum of LOw-primed UnDifferentiated Planarian Stem/Progenitor Cells (CLOUD-PSPCs). Every subclass of neoblast/progenitor cells is a cloud of likelihood, as the single cell transcriptomics data indicate. The CLOUD-HSPCs concept was substantiated by in vitro data from cell culture; therefore, to confirm the CLOUD-PSPCs model, the planarian community needs to develop new tools, like live cell tracking. Future studies will allow a deeper understanding of PBR in planarian, and the possible implications for regenerative therapies in human.
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Affiliation(s)
- Thao Anh Tran
- Pluripotency and Regeneration Group, Fraunhofer Institute for Biomedical Engineering, Joseph-von-Fraunhofer-Weg, 1, 66280, Sulzbach, Germany
| | - Luca Gentile
- Pluripotency and Regeneration Group, Fraunhofer Institute for Biomedical Engineering, Joseph-von-Fraunhofer-Weg, 1, 66280, Sulzbach, Germany; Planarian Stem Cell Laboratory, Max Planck Institute for Molecular Biomedicine, von-Esmarch-str. 54, 48149, Münster, Germany; Hasselt University - Campus Diepenbeek, Agoralaan building D, 3590, Diepenbeek, Belgium.
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7
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Felix DA, Gutiérrez-Gutiérrez Ó, Espada L, Thems A, González-Estévez C. It is not all about regeneration: Planarians striking power to stand starvation. Semin Cell Dev Biol 2018; 87:169-181. [PMID: 29705301 DOI: 10.1016/j.semcdb.2018.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/11/2018] [Accepted: 04/25/2018] [Indexed: 12/12/2022]
Abstract
All living forms, prokaryotes as eukaryotes, have some means of adaptation to food scarcity, which extends the survival chances under extreme environmental conditions. Nowadays we know that dietary interventions, including fasting, extends lifespan of many organisms and can also protect against age-related diseases including in humans. Therefore, the capacity of adapting to periods of food scarcity may have evolved billions of years ago not only to allow immediate organismal survival but also to be able to extend organismal lifespan or at least to lead to a healthier remaining lifespan. Planarians have been the center of attention since more than two centuries because of their astonishing power of full body regeneration that relies on a large amount of adult stem cells or neoblasts. However, they also present an often-overlooked characteristic. They are able to stand long time starvation. Planarians have adapted to periods of fasting by shrinking or degrowing. Here we will review the published data about starvation in planarians and conclude with the possibility of starvation being one of the processes that rejuvenate the planarian, thus explaining the historical notion of non-ageing planarians.
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Affiliation(s)
- Daniel A Felix
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany
| | - Óscar Gutiérrez-Gutiérrez
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany
| | - Lilia Espada
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany
| | - Anne Thems
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany
| | - Cristina González-Estévez
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany.
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8
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Dattani A, Sridhar D, Aziz Aboobaker A. Planarian flatworms as a new model system for understanding the epigenetic regulation of stem cell pluripotency and differentiation. Semin Cell Dev Biol 2018; 87:79-94. [PMID: 29694837 DOI: 10.1016/j.semcdb.2018.04.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/21/2018] [Indexed: 12/11/2022]
Abstract
Planarian flatworms possess pluripotent stem cells (neoblasts) that are able to differentiate into all cell types that constitute the adult body plan. Consequently, planarians possess remarkable regenerative capabilities. Transcriptomic studies have revealed that gene expression is coordinated to maintain neoblast pluripotency, and ensure correct lineage specification during differentiation. But as yet they have not revealed how this regulation of expression is controlled. In this review, we propose that planarians represent a unique and effective system to study the epigenetic regulation of these processes in an in vivo context. We consolidate evidence suggesting that although DNA methylation is likely present in some flatworm lineages, it does not regulate neoblast function in Schmidtea mediterranea. A number of phenotypic studies have documented the role of histone modification and chromatin remodelling complexes in regulating distinct neoblast processes, and we focus on four important examples of planarian epigenetic regulators: Nucleosome Remodeling Deacetylase (NuRD) complex, Polycomb Repressive Complex (PRC), the SET1/MLL methyltransferases, and the nuclear PIWI/piRNA complex. Given the recent advent of ChIP-seq in planarians, we propose future avenues of research that will identify the genomic targets of these complexes allowing for a clearer picture of how neoblast processes are coordinated at the epigenetic level. These insights into neoblast biology may be directly relevant to mammalian stem cells and disease. The unique biology of planarians will also allow us to investigate how extracellular signals feed into epigenetic regulatory networks to govern concerted neoblast responses during regenerative polarity, tissue patterning, and remodelling.
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Affiliation(s)
- Anish Dattani
- Department of Zoology, South Parks Road, University of Oxford, OX1 3PS, UK.
| | - Divya Sridhar
- Department of Zoology, South Parks Road, University of Oxford, OX1 3PS, UK
| | - A Aziz Aboobaker
- Department of Zoology, South Parks Road, University of Oxford, OX1 3PS, UK.
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9
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Galliot B, Crescenzi M, Jacinto A, Tajbakhsh S. Trends in tissue repair and regeneration. Development 2017; 144:357-364. [PMID: 28143842 DOI: 10.1242/dev.144279] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The 6th EMBO conference on the Molecular and Cellular Basis of Regeneration and Tissue Repair took place in Paestum (Italy) on the 17th-21st September, 2016. The 160 scientists who attended discussed the importance of cellular and tissue plasticity, biophysical aspects of regeneration, the diverse roles of injury-induced immune responses, strategies to reactivate regeneration in mammals, links between regeneration and ageing, and the impact of non-mammalian models on regenerative medicine.
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Affiliation(s)
- Brigitte Galliot
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, CH-1211 Geneva 04, Switzerland
| | - Marco Crescenzi
- Department of Cell Biology and Neurosciences, National Institute of Health, I-00161 Roma, Italy
| | - Antonio Jacinto
- CEDOC, NOVA Medical School, NOVA University of Lisbon, Lisboa 1169-056, Portugal
| | - Shahragim Tajbakhsh
- Department of Developmental & Stem Cell Biology, Stem Cells & Development Unit, CNRS UMR 3738, Institut Pasteur, 75015 Paris, France
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10
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Sahu S, Dattani A, Aboobaker AA. Secrets from immortal worms: What can we learn about biological ageing from the planarian model system? Semin Cell Dev Biol 2017; 70:108-121. [PMID: 28818620 DOI: 10.1016/j.semcdb.2017.08.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/07/2017] [Accepted: 08/09/2017] [Indexed: 12/12/2022]
Abstract
Understanding how some animals are immortal and avoid the ageing process is important. We currently know very little about how they achieve this. Research with genetic model systems has revealed the existence of conserved genetic pathways and molecular processes that affect longevity. Most of these established model organisms have relatively short lifespans. Here we consider the use of planarians, with an immortal life-history that is able to entirely avoid the ageing process. These animals are capable of profound feats of regeneration fueled by a population of adult stem cells called neoblasts. These cells are capable of indefinite self-renewal that has underpinned the evolution of animals that reproduce only by fission, having disposed of the germline, and must therefore be somatically immortal and avoid the ageing process. How they do this is only now starting to be understood. Here we suggest that the evidence so far supports the hypothesis that the lack of ageing is an emergent property of both being highly regenerative and the evolution of highly effective mechanisms for ensuring genome stability in the neoblast stem cell population. The details of these mechanisms could prove to be very informative in understanding how the causes of ageing can be avoided, slowed or even reversed.
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Affiliation(s)
- Sounak Sahu
- Department of Zoology, South Parks Road, University of Oxford, Oxford OX1 3PS, UK
| | - Anish Dattani
- Department of Zoology, South Parks Road, University of Oxford, Oxford OX1 3PS, UK
| | - A Aziz Aboobaker
- Department of Zoology, South Parks Road, University of Oxford, Oxford OX1 3PS, UK.
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11
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LoCascio SA, Lapan SW, Reddien PW. Eye Absence Does Not Regulate Planarian Stem Cells during Eye Regeneration. Dev Cell 2017; 40:381-391.e3. [PMID: 28245923 DOI: 10.1016/j.devcel.2017.02.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 01/06/2017] [Accepted: 02/01/2017] [Indexed: 12/28/2022]
Abstract
Dividing cells called neoblasts contain pluripotent stem cells and drive planarian flatworm regeneration from diverse injuries. A long-standing question is whether neoblasts directly sense and respond to the identity of missing tissues during regeneration. We used the eye to investigate this question. Surprisingly, eye removal was neither sufficient nor necessary for neoblasts to increase eye progenitor production. Neoblasts normally increase eye progenitor production following decapitation, facilitating regeneration. Eye removal alone, however, did not induce this response. Eye regeneration following eye-specific resection resulted from homeostatic rates of eye progenitor production and less cell death in the regenerating eye. Conversely, large head injuries that left eyes intact increased eye progenitor production. Large injuries also non-specifically increased progenitor production for multiple uninjured tissues. We propose a model for eye regeneration in which eye tissue production by planarian stem cells is not directly regulated by the absence of the eye itself.
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Affiliation(s)
- Samuel A LoCascio
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA; Howard Hughes Medical Institute, MIT, Cambridge, MA 02139, USA
| | - Sylvain W Lapan
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, MIT, Cambridge, MA 02139, USA
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, MIT, Cambridge, MA 02139, USA.
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12
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Måløy M, Måløy F, Jakobsen P, Olav Brandsdal B. Dynamic self-organisation of haematopoiesis and (a)symmetric cell division. J Theor Biol 2017; 414:147-164. [DOI: 10.1016/j.jtbi.2016.11.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 11/06/2016] [Accepted: 11/30/2016] [Indexed: 12/24/2022]
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