1
|
Gąsiorowski L, Chai C, Rozanski A, Purandare G, Ficze F, Mizi A, Wang B, Rink JC. Regeneration in the absence of canonical neoblasts in an early branching flatworm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.24.595708. [PMID: 38853907 PMCID: PMC11160568 DOI: 10.1101/2024.05.24.595708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The remarkable regenerative abilities of flatworms are closely linked to neoblasts - adult pluripotent stem cells that are the only division-competent cell type outside of the reproductive system. Although the presence of neoblast-like cells and whole-body regeneration in other animals has led to the idea that these features may represent the ancestral metazoan state, the evolutionary origin of both remains unclear. Here we show that the catenulid Stenostomum brevipharyngium, a member of the earliest-branching flatworm lineage, lacks conventional neoblasts despite being capable of whole-body regeneration and asexual reproduction. Using a combination of single-nuclei transcriptomics, in situ gene expression analysis, and functional experiments, we find that cell divisions are not restricted to a single cell type and are associated with multiple fully differentiated somatic tissues. Furthermore, the cohort of germline multipotency genes, which are considered canonical neoblast markers, are not expressed in dividing cells, but in the germline instead, and we experimentally show that they are neither necessary for proliferation nor regeneration. Overall, our results challenge the notion that canonical neoblasts are necessary for flatworm regeneration and open up the possibility that neoblast-like cells may have evolved convergently in different animals, independent of their regenerative capacity.
Collapse
Affiliation(s)
- Ludwik Gąsiorowski
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, USA
| | - Andrei Rozanski
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Gargi Purandare
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Fruzsina Ficze
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Athanasia Mizi
- Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, USA
| | - Jochen C Rink
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| |
Collapse
|
2
|
Lindsay-Mosher N, Lusk S, Pearson BJ. Planarians require ced-12/elmo-1 to clear dead cells by excretion through the gut. Cell Rep 2024; 43:113621. [PMID: 38165802 DOI: 10.1016/j.celrep.2023.113621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 10/13/2023] [Accepted: 12/08/2023] [Indexed: 01/04/2024] Open
Abstract
Cell corpse removal is a critical component of both development and homeostasis throughout the animal kingdom. Extensive research has revealed many of the mechanisms involved in corpse removal, typically involving engulfment and digestion by another cell; however, the dynamics of cell corpse clearance in adult tissues remain unclear. Here, we track cell death in the adult planarian Schmidtea mediterranea and find that, following light-induced cell death, pigment cell corpses transit to the gut and are excreted from the animal. Gut phagocytes, previously only known to phagocytose food, are required for pigment cells to enter the gut lumen. Finally, we show that the planarian ortholog of ced-12/engulfment and cell motility (ELMO) is required for corpse phagocytosis and removal through the gut. In total, we present a mechanism of cell clearance in an adult organism involving transit of dead cells to the gut, transport into the gut by phagocytes, and physical excretion of debris.
Collapse
Affiliation(s)
- Nicole Lindsay-Mosher
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON M5G0A4, Canada; University of Toronto, Department of Molecular Genetics, Toronto, ON, Canada
| | - Sarah Lusk
- Papé Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA
| | - Bret J Pearson
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON M5G0A4, Canada; University of Toronto, Department of Molecular Genetics, Toronto, ON, Canada; Papé Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA.
| |
Collapse
|
3
|
Molina MD, Abduljabbar D, Guixeras A, Fraguas S, Cebrià F. LIM-HD transcription factors control axial patterning and specify distinct neuronal and intestinal cell identities in planarians. Open Biol 2023; 13:230327. [PMID: 38086422 PMCID: PMC10715919 DOI: 10.1098/rsob.230327] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 11/01/2023] [Indexed: 12/18/2023] Open
Abstract
Adult planarians can regenerate the gut, eyes and even a functional brain. Proper identity and patterning of the newly formed structures require signals that guide and commit their adult stem cells. During embryogenesis, LIM-homeodomain (LIM-HD) transcription factors act in a combinatorial 'LIM code' to control cell fate determination and differentiation. However, our understanding about the role these genes play during regeneration and homeostasis is limited. Here, we report the full repertoire of LIM-HD genes in Schmidtea mediterranea. We found that lim homeobox (lhx) genes appear expressed in complementary patterns along the cephalic ganglia and digestive system of the planarian, with some of them being co-expressed in the same cell types. We have identified that Smed-islet1, -lhx1/5-1, -lhx2/9-3, -lhx6/8, -lmx1a/b-2 and -lmx1a/b-3 are essential to pattern and size the planarian brain as well as for correct regeneration of specific subpopulations of dopaminergic, serotonergic, GABAergic and cholinergic neurons, while Smed-lhx1/5.2 and -lhx2/9.2 are required for the proper expression of intestinal cell type markers, specifically the goblet subtype. LIM-HD are also involved in controlling axonal pathfinding (lhx6/8), axial patterning (islet1, lhx1/5-1, lmx1a/b-3), head/body proportions (islet2) and stem cell proliferation (lhx3/4, lhx2/9-3, lmx1a/b-2, lmx1a/b-3). Altogether, our results suggest that planarians might present a combinatorial LIM code that controls axial patterning and axonal growing and specifies distinct neuronal and intestinal cell identities.
Collapse
Affiliation(s)
- M. Dolores Molina
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Dema Abduljabbar
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Anna Guixeras
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Susanna Fraguas
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Francesc Cebrià
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| |
Collapse
|
4
|
Park C, Owusu-Boaitey KE, Valdes GM, Reddien PW. Fate specification is spatially intermingled across planarian stem cells. Nat Commun 2023; 14:7422. [PMID: 37973979 PMCID: PMC10654723 DOI: 10.1038/s41467-023-43267-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 11/06/2023] [Indexed: 11/19/2023] Open
Abstract
Regeneration requires mechanisms for producing a wide array of cell types. Neoblasts are stem cells in the planarian Schmidtea mediterranea that undergo fate specification to produce over 125 adult cell types. Fate specification in neoblasts can be regulated through expression of fate-specific transcription factors. We utilize multiplexed error-robust fluorescence in situ hybridization (MERFISH) and whole-mount FISH to characterize fate choice distribution of stem cells within planarians. Fate choices are often made distant from target tissues and in a highly intermingled manner, with neighboring neoblasts frequently making divergent fate choices for tissues of different location and function. We propose that pattern formation is driven primarily by the migratory assortment of progenitors from mixed and spatially distributed fate-specified stem cells and that fate choice involves stem-cell intrinsic processes.
Collapse
Affiliation(s)
- Chanyoung Park
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kwadwo E Owusu-Boaitey
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
- Harvard/MIT MD-PhD Program, Harvard Medical School, Boston, MA, USA
| | - Giselle M Valdes
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| |
Collapse
|
5
|
Ermakov A, Kudykina N, Bykova A, Tkacheva U. Morphogenic Effect of Exogenous Glucocorticoid Hormones in the Girardia tigrina Planarian ( Turbellaria, Tricladida). BIOLOGY 2023; 12:292. [PMID: 36829568 PMCID: PMC9953184 DOI: 10.3390/biology12020292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/31/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023]
Abstract
We have studied the effect of two glucocorticoid hormones: hydrocortisone and its synthetic analogue methylprednisolone on the regeneration activity of head and tail blastema of the Girardia tigrina planarian. The regeneration activity was studied in head and tail blastema formed after resection by means of lifetime computer morphometry and immunohistochemical labeling of neoblasts. The search for orthologous proteins-glucocorticoid receptors (hydrocortisone) was performed using the SmedGD database of the Schmidtea mediterranea planarian. The results indicate that both hormones influence the recovery rate of the regenerating head and tail blastema. The worms with regenerating tail blastema have less sensitivity to the hormones' treatment compared to the ones with regenerating head blastema. Hydrocortisone at a high concentration (10-3 M) suppressed the regeneration rate, while stimulating it at lower concentrations (10-4-10-6 M). The same concentrations of methylprednisolone inhibited the regeneration of head blastema, but did not affect the tail blastema regeneration. The two hormones acted differently: while hydrocortisone stimulated the proliferation of neoblasts in the periwound region, methylprednisolone reduced the mitotic activity, mainly on the tail zone furthest from the wound surface. We suggest that exogenous glucocorticoids can influence endogenous mechanisms of hormone-dependent regeneration.
Collapse
Affiliation(s)
- Artem Ermakov
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Natalia Kudykina
- Institute of Medicine and Living System, Immanuel Kant Baltic Federal University, 236041 Kaliningrad, Russia
| | - Arina Bykova
- Institute of Medicine and Living System, Immanuel Kant Baltic Federal University, 236041 Kaliningrad, Russia
| | - Ulyana Tkacheva
- Institute of Medicine and Living System, Immanuel Kant Baltic Federal University, 236041 Kaliningrad, Russia
| |
Collapse
|
6
|
Pearson BJ. Finding the potency in planarians. Commun Biol 2022; 5:970. [PMID: 36109651 PMCID: PMC9477812 DOI: 10.1038/s42003-022-03905-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/26/2022] [Indexed: 11/26/2022] Open
Abstract
Recent developments in the field of planarian stem cell research are discussed, an active and accessible stem cell system that can generate any cell type of the planarian body, to address the question of pluripotency among neoblasts.
Collapse
|
7
|
Duncan EM, Nowotarski SH, Guerrero-Hernández C, Ross EJ, D'Orazio JA, McKinney S, McHargue MC, Guo L, McClain M, Alvarado AS. Molecular characterization of a flatworm Girardia isolate from Guanajuato, Mexico. Dev Biol 2022; 489:165-177. [PMID: 35710033 PMCID: PMC11104013 DOI: 10.1016/j.ydbio.2022.06.003] [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: 03/20/2022] [Revised: 05/28/2022] [Accepted: 06/08/2022] [Indexed: 11/03/2022]
Abstract
Planarian flatworms are best known for their impressive regenerative capacity, yet this trait varies across species. In addition, planarians have other features that share morphology and function with the tissues of many other animals, including an outer mucociliary epithelium that drives planarian locomotion and is very similar to the epithelial linings of the human lung and oviduct. Planarians occupy a broad range of ecological habitats and are known to be sensitive to changes in their environment. Yet, despite their potential to provide valuable insight to many different fields, very few planarian species have been developed as laboratory models for mechanism-based research. Here we describe a previously undocumented planarian isolate, Girardia sp. (Guanajuato). After collecting this isolate from a freshwater habitat in central Mexico, we characterized it at the morphological, cellular, and molecular level. We show that Girardia sp. (Guanajuato) not only shares features with animals in the Girardia genus but also possesses traits that appear unique to this isolate. By thoroughly characterizing this new planarian isolate, our work facilitates future comparisons to other flatworms and further molecular dissection of the unique and physiologically-relevant traits observed in this Girardia sp. (Guanajuato) isolate.
Collapse
Affiliation(s)
| | - Stephanie H Nowotarski
- Stowers Institute for Medical Research, Kansas City, MO, USA; Howard Hughes Medical Institute, Kansas City, MO, USA
| | | | - Eric J Ross
- Stowers Institute for Medical Research, Kansas City, MO, USA; Howard Hughes Medical Institute, Kansas City, MO, USA
| | | | - Sean McKinney
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | | | - Longhua Guo
- University of California, Los Angeles, CA, USA
| | | | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, Kansas City, MO, USA; Howard Hughes Medical Institute, Kansas City, MO, USA.
| |
Collapse
|
8
|
Neiro J, Sridhar D, Dattani A, Aboobaker A. Identification of putative enhancer-like elements predicts regulatory networks active in planarian adult stem cells. eLife 2022; 11:79675. [PMID: 35997250 PMCID: PMC9522251 DOI: 10.7554/elife.79675] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
Planarians have become an established model system to study regeneration and stem cells, but the regulatory elements in the genome remain almost entirely undescribed. Here, by integrating epigenetic and expression data we use multiple sources of evidence to predict enhancer elements active in the adult stem cell populations that drive regeneration. We have used ChIP-seq data to identify genomic regions with histone modifications consistent with enhancer activity, and ATAC-seq data to identify accessible chromatin. Overlapping these signals allowed for the identification of a set of high-confidence candidate enhancers predicted to be active in planarian adult stem cells. These enhancers are enriched for predicted transcription factor (TF) binding sites for TFs and TF families expressed in planarian adult stem cells. Footprinting analyses provided further evidence that these potential TF binding sites are likely to be occupied in adult stem cells. We integrated these analyses to build testable hypotheses for the regulatory function of TFs in stem cells, both with respect to how pluripotency might be regulated, and to how lineage differentiation programs are controlled. We found that our predicted GRNs were independently supported by existing TF RNAi/RNA-seq datasets, providing further evidence that our work predicts active enhancers that regulate adult stem cells and regenerative mechanisms.
Collapse
Affiliation(s)
- Jakke Neiro
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Divya Sridhar
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Anish Dattani
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - Aziz Aboobaker
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
9
|
Davidian D, LeGro M, Barghouth PG, Rojas S, Ziman B, Maciel EI, Ardell D, Escobar AL, Oviedo NJ. Restoration of DNA integrity and cell cycle by electric stimulation in planarian tissues damaged by ionizing radiation. J Cell Sci 2022; 135:274829. [PMID: 35322853 PMCID: PMC9264365 DOI: 10.1242/jcs.259304] [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: 08/19/2021] [Accepted: 03/05/2022] [Indexed: 10/18/2022] Open
Abstract
Exposure to high levels of ionizing γ-radiation leads to irreversible DNA damage and cell death. Here, we establish that exogenous application of electric stimulation enables cellular plasticity to reestablish stem cell activity in tissues damaged by ionizing radiation. We show that sub-threshold direct current stimulation (DCS) rapidly restores pluripotent stem cell populations previously eliminated by lethally γ-irradiated tissues of the planarian flatworm Schmidtea mediterranea. Our findings reveal that DCS enhances DNA repair, transcriptional activity, and cell cycle entry in post-mitotic cells. These responses involve rapid increases in cytosolic [Ca2+] through the activation of L-type Cav channels and intracellular Ca2+ stores leading to the activation of immediate early genes and ectopic expression of stem cell markers in postmitotic cells. Overall, we show the potential of electric current stimulation to reverse the damaging effects of high dose γ-radiation in adult tissues. Furthermore, our results provide mechanistic insights describing how electric stimulation effectively translates into molecular responses capable of regulating fundamental cellular functions without the need for genetic or pharmacological intervention.
Collapse
Affiliation(s)
- Devon Davidian
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Melanie LeGro
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Paul G Barghouth
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Salvador Rojas
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Benjamin Ziman
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Eli Isael Maciel
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - David Ardell
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Health Sciences Research Institute, University of California, Merced, USA
| | - Ariel L Escobar
- Department of Bioengineering, University of California, Merced, USA.,Health Sciences Research Institute, University of California, Merced, USA
| | - Néstor J Oviedo
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Health Sciences Research Institute, University of California, Merced, USA
| |
Collapse
|
10
|
Rinkevich B, Ballarin L, Martinez P, Somorjai I, Ben‐Hamo O, Borisenko I, Berezikov E, Ereskovsky A, Gazave E, Khnykin D, Manni L, Petukhova O, Rosner A, Röttinger E, Spagnuolo A, Sugni M, Tiozzo S, Hobmayer B. A pan-metazoan concept for adult stem cells: the wobbling Penrose landscape. Biol Rev Camb Philos Soc 2022; 97:299-325. [PMID: 34617397 PMCID: PMC9292022 DOI: 10.1111/brv.12801] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022]
Abstract
Adult stem cells (ASCs) in vertebrates and model invertebrates (e.g. Drosophila melanogaster) are typically long-lived, lineage-restricted, clonogenic and quiescent cells with somatic descendants and tissue/organ-restricted activities. Such ASCs are mostly rare, morphologically undifferentiated, and undergo asymmetric cell division. Characterized by 'stemness' gene expression, they can regulate tissue/organ homeostasis, repair and regeneration. By contrast, analysis of other animal phyla shows that ASCs emerge at different life stages, present both differentiated and undifferentiated phenotypes, and may possess amoeboid movement. Usually pluri/totipotent, they may express germ-cell markers, but often lack germ-line sequestering, and typically do not reside in discrete niches. ASCs may constitute up to 40% of animal cells, and participate in a range of biological phenomena, from whole-body regeneration, dormancy, and agametic asexual reproduction, to indeterminate growth. They are considered legitimate units of selection. Conceptualizing this divergence, we present an alternative stemness metaphor to the Waddington landscape: the 'wobbling Penrose' landscape. Here, totipotent ASCs adopt ascending/descending courses of an 'Escherian stairwell', in a lifelong totipotency pathway. ASCs may also travel along lower stemness echelons to reach fully differentiated states. However, from any starting state, cells can change their stemness status, underscoring their dynamic cellular potencies. Thus, vertebrate ASCs may reflect just one metazoan ASC archetype.
Collapse
Affiliation(s)
- Baruch Rinkevich
- Israel Oceanographic & Limnological ResearchNational Institute of OceanographyPOB 9753, Tel ShikmonaHaifa3109701Israel
| | - Loriano Ballarin
- Department of BiologyUniversity of PadovaVia Ugo Bassi 58/BPadova35121Italy
| | - Pedro Martinez
- Departament de Genètica, Microbiologia i EstadísticaUniversitat de BarcelonaAv. Diagonal 643Barcelona08028Spain
- Institut Català de Recerca i Estudis Avançats (ICREA)Passeig Lluís Companys 23Barcelona08010Spain
| | - Ildiko Somorjai
- School of BiologyUniversity of St AndrewsSt Andrews, FifeKY16 9ST, ScotlandUK
| | - Oshrat Ben‐Hamo
- Israel Oceanographic & Limnological ResearchNational Institute of OceanographyPOB 9753, Tel ShikmonaHaifa3109701Israel
| | - Ilya Borisenko
- Department of Embryology, Faculty of BiologySaint‐Petersburg State UniversityUniversity Embankment, 7/9Saint‐Petersburg199034Russia
| | - Eugene Berezikov
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center GroningenAntonius Deusinglaan 1Groningen9713 AVThe Netherlands
| | - Alexander Ereskovsky
- Department of Embryology, Faculty of BiologySaint‐Petersburg State UniversityUniversity Embankment, 7/9Saint‐Petersburg199034Russia
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE), Aix Marseille University, CNRS, IRD, Avignon UniversityJardin du Pharo, 58 Boulevard Charles LivonMarseille13007France
- Koltzov Institute of Developmental Biology of Russian Academy of SciencesUlitsa Vavilova, 26Moscow119334Russia
| | - Eve Gazave
- Université de Paris, CNRS, Institut Jacques MonodParisF‐75006France
| | - Denis Khnykin
- Department of PathologyOslo University HospitalBygg 19, Gaustad Sykehus, Sognsvannsveien 21Oslo0188Norway
| | - Lucia Manni
- Department of BiologyUniversity of PadovaVia Ugo Bassi 58/BPadova35121Italy
| | - Olga Petukhova
- Collection of Vertebrate Cell CulturesInstitute of Cytology, Russian Academy of SciencesTikhoretsky Ave. 4St. Petersburg194064Russia
| | - Amalia Rosner
- Israel Oceanographic & Limnological ResearchNational Institute of OceanographyPOB 9753, Tel ShikmonaHaifa3109701Israel
| | - Eric Röttinger
- Université Côte d'Azur, CNRS, INSERM, Institute for Research on Cancer and Aging, Nice (IRCAN)Nice06107France
- Université Côte d'Azur, Federative Research Institute – Marine Resources (IFR MARRES)28 Avenue de ValroseNice06103France
| | - Antonietta Spagnuolo
- Department of Biology and Evolution of Marine OrganismsStazione Zoologica Anton DohrnVilla ComunaleNaples80121Italy
| | - Michela Sugni
- Department of Environmental Science and Policy (ESP)Università degli Studi di MilanoVia Celoria 26Milan20133Italy
| | - Stefano Tiozzo
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche‐sur‐mer (LBDV)06234 Villefranche‐sur‐MerVillefranche sur MerCedexFrance
| | - Bert Hobmayer
- Institute of Zoology and Center for Molecular Biosciences, University of InnsbruckTechnikerstrInnsbruck256020Austria
| |
Collapse
|
11
|
Zheng M, Zueva O, Hinman V. Regeneration of the larval sea star nervous system by wounding induced respecification to the sox2 lineage. eLife 2022; 11:72983. [PMID: 35029145 PMCID: PMC8809897 DOI: 10.7554/elife.72983] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 01/13/2022] [Indexed: 11/20/2022] Open
Abstract
The ability to restore lost body parts following traumatic injury is a fascinating area of biology that challenges current understanding of the ontogeny of differentiation. The origin of new cells needed to regenerate lost tissue, and whether they are pluripotent or have de- or trans-differentiated, remains one of the most important open questions . Additionally, it is not known whether developmental gene regulatory networks are reused or whether regeneration specific networks are deployed. Echinoderms, including sea stars, have extensive ability for regeneration, however, the technologies for obtaining transgenic echinoderms are limited and tracking cells involved in regeneration, and thus identifying the cellular sources and potencies has proven challenging. In this study, we develop new transgenic tools to follow the fate of populations of cells in the regenerating larva of the sea star Patiria miniata. We show that the larval serotonergic nervous system can regenerate following decapitation. Using a BAC-transgenesis approach we show that expression of the pan ectodermal marker, sox2, is induced in previously sox2 minus cells , even when cell division is inhibited. sox2+ cells give rise to new sox4+ neural precursors that then proceed along an embryonic neurogenesis pathway to reform the anterior nervous systems. sox2+ cells contribute to only neural and ectoderm lineages, indicating that these progenitors maintain their normal, embryonic lineage restriction. This indicates that sea star larval regeneration uses a combination of existing lineage restricted stem cells, as well as respecification of cells into neural lineages, and at least partial reuse of developmental GRNs to regenerate their nervous system.
Collapse
Affiliation(s)
- Minyan Zheng
- Department of Genetics, Harvard Medical School, Boston, United States
| | - Olga Zueva
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, United States
| | - Veronica Hinman
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, United States
| |
Collapse
|
12
|
Reddien PW. Principles of regeneration revealed by the planarian eye. Curr Opin Cell Biol 2021; 73:19-25. [PMID: 34134046 PMCID: PMC11064094 DOI: 10.1016/j.ceb.2021.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/06/2021] [Indexed: 02/07/2023]
Abstract
One approach to elucidating the principles of regeneration is to investigate mechanisms that regenerate a target organ. Planarian eyes are discrete, visible structures that are dispensable for viability, making them powerful for studying the logic of regeneration. Fate specification in eye regeneration occurs in stem cells (neoblasts), generating eye progenitors. Eye progenitor production is not responsive to the presence or absence of the eye, with regeneration explained by constant progenitor production in the appropriate positional environment. Eye progenitors display coarse spatial specification. A combination of eye-extrinsic cues and self-organization with differentiated eye cells dictate where migratory eye progenitors target. Finally, guidepost-like cells influence regenerating axons to facilitate the restoration of eye circuitry. These findings from the eye as a case study present a model that explains how regeneration can occur.
Collapse
Affiliation(s)
- 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.
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Raz AA, Wurtzel O, Reddien PW. Planarian stem cells specify fate yet retain potency during the cell cycle. Cell Stem Cell 2021; 28:1307-1322.e5. [PMID: 33882291 DOI: 10.1016/j.stem.2021.03.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 01/08/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023]
Abstract
Planarian whole-body regeneration is enabled by stem cells called neoblasts. At least some neoblasts are individually pluripotent. Neoblasts are also heterogeneous, with subpopulations of specialized neoblasts having different specified fates. Fate specification in neoblasts is regulated by fate-specific transcription factor (FSTF) expression. Here, we find that FSTF expression is common in neoblast S/G2/M cell-cycle phases but less common in G1. We find that specialized neoblasts can divide to produce progeny with asymmetric cell fates, suggesting that they could retain pluripotency. Furthermore, no known neoblast class was present in all neoblast colonies, suggesting that pluripotency is not the exclusive property of any known class. We tested this possibility with single-cell transplantations, which indicate that at least some specialized neoblasts are likely clonogenic. On the basis of these findings, we propose a model for neoblast pluripotency in which neoblasts can undergo specialization during the cell cycle without loss of potency.
Collapse
Affiliation(s)
- Amelie A Raz
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Omri Wurtzel
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
| |
Collapse
|
15
|
Collagen IV differentially regulates planarian stem cell potency and lineage progression. Proc Natl Acad Sci U S A 2021; 118:2021251118. [PMID: 33859045 PMCID: PMC8072372 DOI: 10.1073/pnas.2021251118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Comprehensive assessment of matrisome genes identified collagen IV as one of the many extracellular matrix (ECM) proteins regulating the stem cell pool in planarian tissue homeostasis and regeneration. While collagen IV has been shown to be involved in stem cell biology, our finding links it to pluripotent stem cells in vivo, including self-renewal and differentiation into tissue-specific progenitors. We show a link between the ECM niches in the parenchyma/gut region and EGF/neuregulin-secreting neurons, thus providing mechanistic insight into interactions between cell niches. The conservation of basement membranes between planarian and mammalian gut niches suggests a similar interplay may exist in the mammalian systems, worthy of further investigation. The extracellular matrix (ECM) provides a precise physical and molecular environment for cell maintenance, self-renewal, and differentiation in the stem cell niche. However, the nature and organization of the ECM niche is not well understood. The adult freshwater planarian Schmidtea mediterranea maintains a large population of multipotent stem cells (neoblasts), presenting an ideal model to study the role of the ECM niche in stem cell regulation. Here we tested the function of 165 planarian homologs of ECM and ECM-related genes in neoblast regulation. We identified the collagen gene family as one with differential effects in promoting or suppressing proliferation of neoblasts. col4-1, encoding a type IV collagen α-chain, had the strongest effect. RNA interference (RNAi) of col4-1 impaired tissue maintenance and regeneration, causing tissue regression. Finally, we provide evidence for an interaction between type IV collagen, the discoidin domain receptor, and neuregulin-7 (NRG-7), which constitutes a mechanism to regulate the balance of symmetric and asymmetric division of neoblasts via the NRG-7/EGFR pathway.
Collapse
|
16
|
Fraguas S, Cárcel S, Vivancos C, Molina MD, Ginés J, Mazariegos J, Sekaran T, Bartscherer K, Romero R, Cebrià F. CREB-binding protein (CBP) gene family regulates planarian survival and stem cell differentiation. Dev Biol 2021; 476:53-67. [PMID: 33774010 DOI: 10.1016/j.ydbio.2021.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 12/21/2022]
Abstract
In developmental biology, the regulation of stem cell plasticity and differentiation remains an open question. CBP(CREB-binding protein)/p300 is a conserved gene family that functions as a transcriptional co-activator and plays important roles in a wide range of cellular processes, including cell death, the DNA damage response, and tumorigenesis. The acetyl transferase activity of CBPs is particularly important, as histone and non-histone acetylation results in changes in chromatin architecture and protein activity that affect gene expression. Many studies have described the conserved functions of CBP/p300 in stem cell proliferation and differentiation. The planarian Schmidtea mediterranea is an excellent model for the in vivo study of the molecular mechanisms underlying stem cell differentiation during regeneration. However, how this process is regulated genetically and epigenetically is not well-understood yet. We identified 5 distinct Smed-cbp genes in S. mediterranea that show different expression patterns. Functional analyses revealed that Smed-cbp-2 appears to be essential for stem cell maintenance. On the other hand, the silencing of Smed-cbp-3 resulted in the growth of blastemas that were apparently normal, but remained largely unpigmented and undifferentiated. Smed-cbp-3 silencing also affected the differentiation of several cell lineages including neural, epidermal, digestive, and excretory cell types. Finally, we analysed the predicted interactomes of CBP-2 and CBP-3 as an initial step to better understand their functions in planarian stem cell biology. Our results indicate that planarian cbp genes play key roles in stem cell maintenance and differentiation.
Collapse
Affiliation(s)
- Susanna Fraguas
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Spain; Institute of Biomedicine of the University of Barcelona (IBUB), Spain
| | - Sheila Cárcel
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Spain
| | - Coral Vivancos
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Spain
| | - Ma Dolores Molina
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Spain; Institute of Biomedicine of the University of Barcelona (IBUB), Spain
| | - Jordi Ginés
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Spain
| | - Judith Mazariegos
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Spain
| | | | | | - Rafael Romero
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Spain
| | - Francesc Cebrià
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Spain; Institute of Biomedicine of the University of Barcelona (IBUB), Spain.
| |
Collapse
|
17
|
Molinaro AM, Lindsay‐Mosher N, Pearson BJ. Identification of TOR-responsive slow-cycling neoblasts in planarians. EMBO Rep 2021; 22:e50292. [PMID: 33511776 PMCID: PMC7926258 DOI: 10.15252/embr.202050292] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 11/19/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
Epimorphic regeneration commonly relies on the activation of reserved stem cells to drive new cell production. The planarian Schmidtea mediterranea is among the best regenerators in nature, thanks to its large population of adult stem cells, called neoblasts. While neoblasts have long been known to drive regeneration, whether a subset of neoblasts is reserved for this purpose is unknown. Here, we revisit the idea of reserved neoblasts by approaching neoblast heterogeneity from a regulatory perspective. By implementing a new fluorescence-activated cell sorting strategy in planarians, we identify a population of neoblasts defined by low transcriptional activity. These RNAlow neoblasts are relatively slow-cycling at homeostasis and undergo a morphological regeneration response characterized by cell growth at 48 h post-amputation. At this time, RNAlow neoblasts proliferate in a TOR-dependent manner. Additionally, knockdown of the tumour suppressor Lrig-1, which is enriched in RNAlow neoblasts, results in RNAlow neoblast growth and hyperproliferation at homeostasis, and ultimately delays regeneration. We propose that slow-cycling RNAlow neoblasts represent a regeneration-reserved neoblast population.
Collapse
Affiliation(s)
- Alyssa M Molinaro
- Program in Developmental and Stem Cell BiologyHospital for Sick ChildrenTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
- Present address:
Department of Systems BiologyHarvard Medical SchoolBostonMAUSA
| | - Nicole Lindsay‐Mosher
- Program in Developmental and Stem Cell BiologyHospital for Sick ChildrenTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
| | - Bret J Pearson
- Program in Developmental and Stem Cell BiologyHospital for Sick ChildrenTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
- Ontario Institute for Cancer ResearchTorontoONCanada
| |
Collapse
|
18
|
Bijnens K, Thijs S, Leynen N, Stevens V, McAmmond B, Van Hamme J, Vangronsveld J, Artois T, Smeets K. Differential effect of silver nanoparticles on the microbiome of adult and developing planaria. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 230:105672. [PMID: 33227667 DOI: 10.1016/j.aquatox.2020.105672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/04/2020] [Accepted: 10/27/2020] [Indexed: 05/23/2023]
Abstract
Silver nanoparticles (AgNPs) are widely incorporated in household, consumer and medical products. Their unintentional release via wastewaters raises concerns on their environmental impact, particularly for aquatic organisms and their associated bacterial communities. It is known that the microbiome plays an important role in its host's health and physiology, e.g. by producing essential nutrients and providing protection against pathogens. A thorough understanding of the effects of AgNPs on bacterial communities and on their interactions with the host is crucial to fully assess AgNP toxicity on aquatic organisms. Our results indicate that the microbiome of the invertebrate Schmidtea mediterranea, a freshwater planarian, is affected by AgNP exposure at the tested 10 μg/ml concentration. Using targeted amplification of the bacterial 16S rRNA gene V3-V4 region, two independent experiments on the microbiomes of adult worms revealed a consistent decrease in Betaproteobacteriales after AgNP exposure, mainly attributed to a decrease in Curvibacter and Undibacterium. Although developing tissues and organisms are known to be more sensitive to toxic compounds, three independent experiments in regenerating worms showed a less pronounced effect of AgNP exposure on the microbiome, possibly because underlying bacterial community changes during development mask the AgNP induced effect. The presence of a polyvinyl-pyrrolidone (PVP) coating did not significantly alter the outcome of the experiments compared to those with uncoated particles. The observed variation between the different experiments underlines the highly variable nature of microbiomes and emphasises the need to repeat microbiome experiments, within and between physiological states of the animal.
Collapse
Affiliation(s)
- Karolien Bijnens
- Centre for Environmental Sciences, Zoology, Biodiversity and Toxicology, Hasselt University, Hasselt, Belgium
| | - Sofie Thijs
- Centre for Environmental Sciences, Environmental Biology, Hasselt University, Hasselt, Belgium
| | - Nathalie Leynen
- Centre for Environmental Sciences, Zoology, Biodiversity and Toxicology, Hasselt University, Hasselt, Belgium
| | - Vincent Stevens
- Centre for Environmental Sciences, Environmental Biology, Hasselt University, Hasselt, Belgium
| | - Breanne McAmmond
- Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada
| | - Jonathan Van Hamme
- Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada
| | - Jaco Vangronsveld
- Centre for Environmental Sciences, Environmental Biology, Hasselt University, Hasselt, Belgium; Department of Plant Physiology, Faculty of Biology and Biotechnology, Maria Skłodowska-Curie University, Lublin, Poland
| | - Tom Artois
- Centre for Environmental Sciences, Zoology, Biodiversity and Toxicology, Hasselt University, Hasselt, Belgium
| | - Karen Smeets
- Centre for Environmental Sciences, Zoology, Biodiversity and Toxicology, Hasselt University, Hasselt, Belgium.
| |
Collapse
|
19
|
Wiggans M, Pearson BJ. One stem cell program to rule them all? FEBS J 2020; 288:3394-3406. [PMID: 33063917 DOI: 10.1111/febs.15598] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/17/2020] [Accepted: 10/12/2020] [Indexed: 12/23/2022]
Abstract
Many species of animals have stem cells that they maintain throughout their lives, which suggests that stem cells are an ancestral feature of all animals. From this, we take the viewpoint that cells with the biological properties of 'stemness'-self-renewal and multipotency-may share ancestral genetic circuitry. However, in practice is it very difficult to identify and compare stemness gene signatures across diverse animals and large evolutionary distances? First, it is critical to experimentally demonstrate self-renewal and potency. Second, genomic methods must be used to determine specific gene expression in stem cell types compared with non-stem cell types to determine stem cell gene enrichment. Third, gene homology must be mapped between diverse animals across large evolutionary distances. Finally, conserved genes that fulfill these criteria must be tested for role in stem cell function. It is our viewpoint that by comparing stem cell-specific gene signatures across evolution, ancestral programs of stemness can be uncovered, and ultimately, the dysregulation of stemness programs drives the state of cancer stem cells.
Collapse
Affiliation(s)
- Mallory Wiggans
- Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, ON, Canada
| | - Bret J Pearson
- Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, ON, Canada.,Ontario Institute for Cancer Research, Toronto, ON, Canada
| |
Collapse
|
20
|
Shiroor DA, Bohr TE, Adler CE. Injury Delays Stem Cell Apoptosis after Radiation in Planarians. Curr Biol 2020; 30:2166-2174.e3. [PMID: 32386527 DOI: 10.1016/j.cub.2020.03.054] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 02/17/2020] [Accepted: 03/20/2020] [Indexed: 12/31/2022]
Abstract
Stem cells are continuously exposed to multiple stresses, including radiation and tissue injury. As central drivers of tissue repair and regeneration, it is necessary to understand how their behavior is influenced by these stressors. Planarians have an abundant population of stem cells that are rapidly eliminated after radiation exposure via apoptosis. Low doses of radiation eliminate the majority of these stem cells, allowing a few to remain [1]. Here, we combine radiation with injury to define how stem cells respond to tissue damage. We find that a variety of injuries induced within a defined window of time surrounding radiation cause stem cells to outlast those in uninjured animals. Injury stimulates localized cell death adjacent to wounds [2], in the same regions where stem cells persist. This persistence occurs in the absence of proliferation. Instead, stem cells are retained near the wound due to delayed apoptosis, which we quantify by combining fluorescence-activated cell sorting (FACS) with annexin V staining. Pharmacological inhibition of the mitogen-activated protein (MAP) kinase extracellular signal-regulated kinase (ERK) prevents stem cell persistence after injury, implicating wound-induced ERK activity in this response. By combining radiation with injury, our work reveals a novel connection between dying cells and stem cells that remain. Furthermore, the ability to induce stem cell persistence after radiation provides a paradigm to study mechanisms that may contribute to unanticipated consequences of injury, such as tumorigenesis.
Collapse
Affiliation(s)
- Divya A Shiroor
- Department of Molecular Medicine, Cornell University of Veterinary Medicine, 930 Campus Road, Ithaca, NY 14853, USA
| | - Tisha E Bohr
- Department of Molecular Medicine, Cornell University of Veterinary Medicine, 930 Campus Road, Ithaca, NY 14853, USA
| | - Carolyn E Adler
- Department of Molecular Medicine, Cornell University of Veterinary Medicine, 930 Campus Road, Ithaca, NY 14853, USA.
| |
Collapse
|
21
|
Planarian EGF repeat-containing genes megf6 and hemicentin are required to restrict the stem cell compartment. PLoS Genet 2020; 16:e1008613. [PMID: 32078629 PMCID: PMC7059952 DOI: 10.1371/journal.pgen.1008613] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 03/06/2020] [Accepted: 01/16/2020] [Indexed: 12/17/2022] Open
Abstract
The extracellular matrix (ECM) is important for maintaining the boundaries between tissues. This role is particularly critical in the stem cell niche, as pre-neoplastic or cancerous stem cells must pass these boundaries in order to invade into the surrounding tissue. Here, we examine the role of the ECM as a regulator of the stem cell compartment in the planarian Schmidtea mediterranea, a highly regenerative, long-lived organism with a large population of adult stem cells. We identify two EGF repeat-containing genes, megf6 and hemicentin, with identical knockdown phenotypes. We find that megf6 and hemicentin are needed to maintain the structure of the basal lamina, and in the absence of either gene, pluripotent stem cells migrate ectopically outside of their compartment and hyper-proliferate, causing lesions in the body wall muscle. These muscle lesions and ectopic stem cells are also associated with ectopic gut branches, which protrude from the normal gut towards the dorsal side of the animal. Interestingly, both megf6 and hemicentin knockdown worms are capable of regenerating tissue free of both muscle lesions and ectopic cells, indicating that these genes are dispensable for regeneration. These results provide insight into the role of planarian ECM in restricting the stem cell compartment, and suggest that signals within the compartment may act to suppress stem cell hyperproliferation. The freshwater planarian maintains a large population of adult stem cells throughout its long lifespan. Although these stem cells are constantly dividing, the rate of division is tightly controlled to such a degree that planarians almost never develop neoplastic growths. In addition, the stem cells are located in a specific spatial compartment within the animal, although no known physical boundary keeps them in place. What mechanisms do planarians use to control the number, rate of division, and location of their stem cells? Here, we find that two EGF repeat-containing genes, megf6 and hemicentin, are required to keep stem cells within their compartment. Although these two genes are expressed in different cell populations, we find that both are required to maintain the epithelial basal lamina. In the absence of either gene, stem cells can escape their compartment and migrate towards the skin of the animal, where they divide at an accelerated rate and cause lesions in the muscle. These results show that the extracellular matrix plays a role in limiting the boundaries of the stem cell compartment.
Collapse
|
22
|
Barghouth PG, Karabinis P, Venegas A, Oviedo NJ. Poly(ADP-Ribose) Polymerase-3 Regulates Regeneration in Planarians. Int J Mol Sci 2020; 21:E875. [PMID: 32013251 PMCID: PMC7038108 DOI: 10.3390/ijms21030875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/27/2020] [Indexed: 11/20/2022] Open
Abstract
Protein ADP-ribosylation is a reversible post-translational modification (PTM) process that plays fundamental roles in cell signaling. The covalent attachment of ADP ribose polymers is executed by PAR polymerases (PARP) and it is essential for chromatin organization, DNA repair, cell cycle, transcription, and replication, among other critical cellular events. The process of PARylation or polyADP-ribosylation is dynamic and takes place across many tissues undergoing renewal and repair, but the molecular mechanisms regulating this PTM remain mostly unknown. Here, we introduce the use of the planarian Schmidtea mediterranea as a tractable model to study PARylation in the complexity of the adult body that is under constant renewal and is capable of regenerating damaged tissues. We identified the evolutionary conservation of PARP signaling that is expressed in planarian stem cells and differentiated tissues. We also demonstrate that Smed-PARP-3 homolog is required for proper regeneration of tissues in the anterior region of the animal. Furthermore, our results demonstrate, Smed-PARP-3(RNAi) disrupts the timely location of injury-induced cell death near the anterior facing wounds and also affects the regeneration of the central nervous system. Our work reveals novel roles for PARylation in large-scale regeneration and provides a simplified platform to investigate PARP signaling in the complexity of the adult body.
Collapse
Affiliation(s)
- Paul G. Barghouth
- Department of Molecular and Cell Biology, University of California, Merced, CA 95340, USA; (P.G.B.); (P.K.); (A.V.)
- Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95340, USA
| | - Peter Karabinis
- Department of Molecular and Cell Biology, University of California, Merced, CA 95340, USA; (P.G.B.); (P.K.); (A.V.)
- Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95340, USA
| | - Andie Venegas
- Department of Molecular and Cell Biology, University of California, Merced, CA 95340, USA; (P.G.B.); (P.K.); (A.V.)
| | - Néstor J. Oviedo
- Department of Molecular and Cell Biology, University of California, Merced, CA 95340, USA; (P.G.B.); (P.K.); (A.V.)
- Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95340, USA
- Health Sciences Research Institute, University of California, Merced, CA 95340, USA
| |
Collapse
|
23
|
Tewari AG, Stern SR, Oderberg IM, Reddien PW. Cellular and Molecular Responses Unique to Major Injury Are Dispensable for Planarian Regeneration. Cell Rep 2019; 25:2577-2590.e3. [PMID: 30485821 PMCID: PMC6475882 DOI: 10.1016/j.celrep.2018.11.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/11/2018] [Accepted: 10/31/2018] [Indexed: 11/18/2022] Open
Abstract
The fundamental requirements for regeneration are poorly understood. Planarians can robustly regenerate all tissues after injury, involving stem cells, positional information, and a set of cellular and molecular responses collectively called the "missing tissue" or "regenerative" response. follistatin, which encodes an extracellular Activin inhibitor, is required for the missing tissue response after head amputation and for subsequent regeneration. We found that follistatin is required for the missing tissue response regardless of the wound context, but causes regeneration failure only after head amputation. This head regeneration failure involves follistatin-mediated regulation of Wnt signaling at wounds and is not a consequence of a diminished missing tissue response. All tested contexts of regeneration, including head regeneration, could occur with a defective missing tissue response, but at a slower pace. Our findings suggest that major cellular and molecular programs induced specifically by large injuries function to accelerate regeneration but are dispensable for regeneration itself.
Collapse
Affiliation(s)
- Aneesha G Tewari
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sarah R Stern
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Isaac M Oderberg
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
| |
Collapse
|
24
|
Kudikina NP, Ermakov AM, Omelnitskaya EA, Skorobogatykh IA. The Morphogenetic Effects of Exogenous Sex Steroid Hormones in the Planarian Girardia tigrina (Turbellaria, Tricladida). Biophysics (Nagoya-shi) 2019. [DOI: 10.1134/s0006350919050142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
25
|
Ochoa SD, Dores MR, Allen JM, Tran T, Osman M, Vázquez Castellanos NP, Trejo J, Zayas RM. A modular laboratory course using planarians to study genes involved in tissue regeneration. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION : A BIMONTHLY PUBLICATION OF THE INTERNATIONAL UNION OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 47:547-559. [PMID: 31194289 PMCID: PMC6731126 DOI: 10.1002/bmb.21259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 04/10/2019] [Accepted: 05/15/2019] [Indexed: 05/02/2023]
Abstract
Undergraduate research experiences are excellent opportunities to engage students in science alongside experienced scientists, but at large institutions, it is challenging to accommodate all students. To address and engage a larger number of students, we developed a modular laboratory course based on the course-based undergraduate research experiences model. This new course was integrated with the scientific aims of a research laboratory studying the cellular and molecular mechanisms underlying tissue regeneration in planarians. In this course, students were asked to identify genes with roles in planarian biology. Students analyzed and cloned an assigned gene, determined its expression pattern in situ and examined its function in regeneration. Additionally, we developed critical thinking and scientific communication skills by incorporating activities focused on critical concepts. Students obtained high quality primary data and were successful in completing and mastering the course learning outcomes. They benefitted by developing basic research skills, learning to perform, trouble-shooting experiments, reading and critically analyzing primary literature, and using the information to defend and explain their experimental results. Through this course, students also increased their confidence and ability to perform independent scientific research. The course was designed to make it accessible to the community to implement and adapt as appropriate in diverse institutions. © 2019 International Union of Biochemistry and Molecular Biology, 47(5):547-559, 2019.
Collapse
Affiliation(s)
- Stacy D Ochoa
- Department of Biology, San Diego State University, San Diego, California
- Department of Pharmacology, University of California San Diego, La Jolla, California
| | - Michael R Dores
- Department of Pharmacology, University of California San Diego, La Jolla, California
- Department of Biology, Hofstra University, Hempstead, New York
| | - John M Allen
- Department of Biology, San Diego State University, San Diego, California
| | - Tuan Tran
- Department of Biology, San Diego State University, San Diego, California
| | - Maryan Osman
- Department of Biology, San Diego State University, San Diego, California
| | | | - JoAnn Trejo
- Department of Pharmacology, University of California San Diego, La Jolla, California
| | - Ricardo M Zayas
- Department of Biology, San Diego State University, San Diego, California
| |
Collapse
|
26
|
Gehrke AR, Neverett E, Luo YJ, Brandt A, Ricci L, Hulett RE, Gompers A, Ruby JG, Rokhsar DS, Reddien PW, Srivastava M. Acoel genome reveals the regulatory landscape of whole-body regeneration. Science 2019; 363:363/6432/eaau6173. [PMID: 30872491 DOI: 10.1126/science.aau6173] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 11/08/2018] [Accepted: 02/08/2019] [Indexed: 12/11/2022]
Abstract
Whole-body regeneration is accompanied by complex transcriptomic changes, yet the chromatin regulatory landscapes that mediate this dynamic response remain unexplored. To decipher the regulatory logic that orchestrates regeneration, we sequenced the genome of the acoel worm Hofstenia miamia, a highly regenerative member of the sister lineage of other bilaterians. Epigenomic profiling revealed thousands of regeneration-responsive chromatin regions and identified dynamically bound transcription factor motifs, with the early growth response (EGR) binding site as the most variably accessible during Hofstenia regeneration. Combining egr inhibition with chromatin profiling suggests that Egr functions as a pioneer factor to directly regulate early wound-induced genes. The genetic connections inferred by this approach allowed the construction of a gene regulatory network for whole-body regeneration, enabling genomics-based comparisons of regeneration across species.
Collapse
Affiliation(s)
- Andrew R Gehrke
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Emily Neverett
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Yi-Jyun Luo
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Alexander Brandt
- Department of Chemistry, University of California, Berkeley, CA 94703, USA
| | - Lorenzo Ricci
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Ryan E Hulett
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Annika Gompers
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - J Graham Ruby
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA
| | - Daniel S Rokhsar
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94703, USA
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Howard Hughes Medical Institute, and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02138, USA
| | - Mansi Srivastava
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA. .,Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA
| |
Collapse
|
27
|
Mouton S, Wudarski J, Grudniewska M, Berezikov E. The regenerative flatworm Macrostomum lignano, a model organism with high experimental potential. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2019; 62:551-558. [PMID: 29938766 DOI: 10.1387/ijdb.180077eb] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Understanding the process of regeneration has been one of the longstanding scientific aims, from a fundamental biological perspective, as well as within the applied context of regenerative medicine. Because regeneration competence varies greatly between organisms, it is essential to investigate different experimental animals. The free-living marine flatworm Macrostomum lignano is a rising model organism for this type of research, and its power stems from a unique set of biological properties combined with amenability to experimental manipulation. The biological properties of interest include production of single-cell fertilized eggs, a transparent body, small size, short generation time, ease of culture, the presence of a pluripotent stem cell population, and a large regeneration competence. These features sparked the development of molecular tools and resources for this animal, including high-quality genome and transcriptome assemblies, gene knockdown, in situ hybridization, and transgenesis. Importantly, M. lignano is currently the only flatworm species for which transgenesis methods are established. This review summarizes biological features of M. lignano and recent technological advances towards experimentation with this animal. In addition, we discuss the experimental potential of this model organism for different research questions related to regeneration and stem cell biology.
Collapse
Affiliation(s)
- Stijn Mouton
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | | | | |
Collapse
|
28
|
Li DJ, McMann CL, Reddien PW. Nuclear receptor NR4A is required for patterning at the ends of the planarian anterior-posterior axis. eLife 2019; 8:42015. [PMID: 31025936 PMCID: PMC6534381 DOI: 10.7554/elife.42015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 04/25/2019] [Indexed: 02/07/2023] Open
Abstract
Positional information is fundamental to animal regeneration and tissue turnover. In planarians, muscle cells express signaling molecules to promote positional identity. At the ends of the anterior-posterior (AP) axis, positional identity is determined by anterior and posterior poles, which are putative organizers. We identified a gene, nr4A, that is required for anterior- and posterior-pole localization to axis extremes. nr4A encodes a nuclear receptor expressed predominantly in planarian muscle, including strongly at AP-axis ends and the poles. nr4A RNAi causes patterning gene expression domains to retract from head and tail tips, and ectopic anterior and posterior anatomy (e.g., eyes) to iteratively appear more internally. Our study reveals a novel patterning phenotype, in which pattern-organizing cells (poles) shift from their normal locations (axis extremes), triggering abnormal tissue pattern that fails to reach equilibrium. We propose that nr4A promotes pattern at planarian AP axis ends through restriction of patterning gene expression domains. Many animals are able to regenerate tissue that has been lost through illness or injury. Flatworms called planarians have long been used to study tissue regeneration because of their remarkable ability to completely regenerate their whole body from small pieces of tissue. Furthermore, the stem cells of adult planarians continually produce new cells to replace dying cells in a process called tissue turnover. For regeneration and tissue turnover to be successful, it is important for the new cells to form in the right location in the body; for example, new eye cells need to form in the head. Genes known as position control genes are active in muscle at specific locations along the body of a flatworm to regulate both regeneration and tissue turnover. However, it was not clear how these genes coordinate with stem cells to produce new cells in the correct positions in the body. Li et al. examined the effects of a gene known as nr4A that is particularly active in muscle at the head and tail ends of planarians. Using a technique called RNA interference to decrease the activity of nr4A in planarians disrupted the patterns of tissues at each end of the flatworms. Over time, the activity of the position control genes also became restricted to locations progressively farther away from the head and tail. As a result, cells that were intended to replace tissues in the head or tail were deposited increasingly far away from these locations. For example, new eyes formed repeatedly in the planarians, with each set farther away from the head tip than the last. Li et al. propose that these disruptions of normal tissue patterning ensue because the cells that organize such patterns at the ends of the planarian (the poles) are themselves misplaced within the existing body pattern. The nr4A gene can be found in a wide range of animal species. Understanding how this gene affects tissue patterns in planarians could therefore also help researchers to discover how adult tissue patterns form and are maintained in animals more generally.
Collapse
Affiliation(s)
- Dayan J Li
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Howard Hughes Medical Institute, Chevy Chase, United States.,Harvard/MIT MD-PhD Program, Harvard Medical School, Boston, United States
| | - Conor L McMann
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Howard Hughes Medical Institute, Chevy Chase, United States
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Howard Hughes Medical Institute, Chevy Chase, United States
| |
Collapse
|
29
|
Planarian regeneration between 1960s and 1990s: From skilful baffled ancestors to bold integrative descendants. A personal account. Semin Cell Dev Biol 2019; 87:3-12. [DOI: 10.1016/j.semcdb.2018.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/13/2018] [Accepted: 04/25/2018] [Indexed: 12/11/2022]
|
30
|
Cary GA, Wolff A, Zueva O, Pattinato J, Hinman VF. Analysis of sea star larval regeneration reveals conserved processes of whole-body regeneration across the metazoa. BMC Biol 2019; 17:16. [PMID: 30795750 PMCID: PMC6385403 DOI: 10.1186/s12915-019-0633-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/04/2019] [Indexed: 12/16/2022] Open
Abstract
Background Metazoan lineages exhibit a wide range of regenerative capabilities that vary among developmental stage and tissue type. The most robust regenerative abilities are apparent in the phyla Cnidaria, Platyhelminthes, and Echinodermata, whose members are capable of whole-body regeneration (WBR). This phenomenon has been well characterized in planarian and hydra models, but the molecular mechanisms of WBR are less established within echinoderms, or any other deuterostome system. Thus, it is not clear to what degree aspects of this regenerative ability are shared among metazoa. Results We characterize regeneration in the larval stage of the Bat Star (Patiria miniata). Following bisection along the anterior-posterior axis, larvae progress through phases of wound healing and re-proportioning of larval tissues. The overall number of proliferating cells is reduced following bisection, and we find evidence for a re-deployment of genes with known roles in embryonic axial patterning. Following axial respecification, we observe a significant localization of proliferating cells to the wound region. Analyses of transcriptome data highlight the molecular signatures of functions that are common to regeneration, including specific signaling pathways and cell cycle controls. Notably, we find evidence for temporal similarities among orthologous genes involved in regeneration from published Platyhelminth and Cnidarian regeneration datasets. Conclusions These analyses show that sea star larval regeneration includes phases of wound response, axis respecification, and wound-proximal proliferation. Commonalities of the overall process of regeneration, as well as gene usage between this deuterostome and other species with divergent evolutionary origins reveal a deep similarity of whole-body regeneration among the metazoa. Electronic supplementary material The online version of this article (10.1186/s12915-019-0633-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Gregory A Cary
- Department of Biological Sciences, Carnegie Mellon University, Mellon Institute, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Andrew Wolff
- Department of Biological Sciences, Carnegie Mellon University, Mellon Institute, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Olga Zueva
- Department of Biological Sciences, Carnegie Mellon University, Mellon Institute, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Joseph Pattinato
- Department of Biological Sciences, Carnegie Mellon University, Mellon Institute, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Veronica F Hinman
- Department of Biological Sciences, Carnegie Mellon University, Mellon Institute, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
31
|
Stevens AS, Wouters A, Ploem JP, Pirotte N, Van Roten A, Willems M, Hellings N, Franken C, Koppen G, Artois T, Plusquin M, Smeets K. Planarians Customize Their Stem Cell Responses Following Genotoxic Stress as a Function of Exposure Time and Regenerative State. Toxicol Sci 2019; 162:251-263. [PMID: 29145667 DOI: 10.1093/toxsci/kfx247] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Aiming to in vivo characterize the responses of pluripotent stem cells and regenerative tissues to carcinogenic stress, we employed the highly regenerative organism Schmidtea mediterranea. Its broad regenerative capacities are attributable to a large pool of pluripotent stem cells, which are considered key players in the lower vulnerability toward chemically induced carcinogenesis observed in regenerative organisms. Schmidtea mediterranea is, therefore, an ideal model to study pluripotent stem cell responses with stem cells residing in their natural environment. Including microenvironmental alterations is important, as the surrounding niche influences the onset of oncogenic events. Both short- (3 days) and long-term (17 days) exposures to the genotoxic carcinogen methyl methanesulfonate (50 µM) were evaluated during homeostasis and animal regeneration, two situations that render altered cellular niches. In both cases, MMS-induced DNA damage was observed, which provoked a decrease in proliferation on the short term. The outcome of DNA damage responses following long-term exposure differed between homeostatic and regenerating animals. During regeneration, DNA repair systems were more easily activated than in animals in homeostasis, where apoptosis was an important outcome. Knockdown experiments confirmed the importance of DNA repair systems during carcinogenic exposure in regenerating animals as knockdown of rad51 induced a stem cell-depleted phenotype, after regeneration was completed.
Collapse
Affiliation(s)
- An-Sofie Stevens
- Zoology: Biodiversity and Toxicology, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium
| | - Annelies Wouters
- Zoology: Biodiversity and Toxicology, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium
| | - Jan-Pieter Ploem
- Zoology: Biodiversity and Toxicology, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium
| | - Nicky Pirotte
- Zoology: Biodiversity and Toxicology, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium
| | - Andromeda Van Roten
- Zoology: Biodiversity and Toxicology, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium
| | - Maxime Willems
- Laboratory of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.,Laboratory of Environmental Toxicology & Aquatic Ecology, Ghent University, 9000 Ghent, Belgium
| | - Niels Hellings
- Biomedical Research Institute, Hasselt University, 3590 Diepenbeek, Belgium
| | - Carmen Franken
- Environmental Risk and Health Unit, Flemish Institute for Technological Research (VITO), 2400 Mol, Belgium
| | - Gudrun Koppen
- Environmental Risk and Health Unit, Flemish Institute for Technological Research (VITO), 2400 Mol, Belgium
| | - Tom Artois
- Zoology: Biodiversity and Toxicology, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium
| | - Michelle Plusquin
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium
| | - Karen Smeets
- Zoology: Biodiversity and Toxicology, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium
| |
Collapse
|
32
|
Alessandra S, Rossi L. Planarian Stem Cell Heterogeneity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1123:39-54. [PMID: 31016594 DOI: 10.1007/978-3-030-11096-3_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Planarian (Platyhelminthes, Triclads) are free-living flatworms endowed with extraordinary regenerative capabilities, i.e., the ability to rebuild any missing body parts also from small fragments. Planarian regenerative capabilities fascinated scientific community since early 1800, including high-standing scientists such as J.T. Morgan and C. M. Child. Today, it is known that planarian regeneration is due to the presence of a wide population of stem cells, the so-called neoblasts. However, the understanding of the nature of cells orchestrating planarian regeneration was a long journey, and several questions still remain unanswered. In this chapter, beginning from the definition of the classical concept of neoblast, we review progressive discoveries that have brought to the modern view of these cells as a highly heterogeneous population of stem cells including pluripotent stem cells and undifferentiated populations of committed progenies.
Collapse
Affiliation(s)
- Salvetti Alessandra
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Leonardo Rossi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
| |
Collapse
|
33
|
Olson PD, Zarowiecki M, James K, Baillie A, Bartl G, Burchell P, Chellappoo A, Jarero F, Tan LY, Holroyd N, Berriman M. Genome-wide transcriptome profiling and spatial expression analyses identify signals and switches of development in tapeworms. EvoDevo 2018; 9:21. [PMID: 30455861 PMCID: PMC6225667 DOI: 10.1186/s13227-018-0110-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 10/05/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Tapeworms are agents of neglected tropical diseases responsible for significant health problems and economic loss. They also exhibit adaptations to a parasitic lifestyle that confound comparisons of their development with other animals. Identifying the genetic factors regulating their complex ontogeny is essential to understanding unique aspects of their biology and for advancing novel therapeutics. Here we use RNA sequencing to identify up-regulated signalling components, transcription factors and post-transcriptional/translational regulators (genes of interest, GOI) in the transcriptomes of Larvae and different regions of segmented worms in the tapeworm Hymenolepis microstoma and combine this with spatial gene expression analyses of a selection of genes. RESULTS RNA-seq reads collectively mapped to 90% of the > 12,000 gene models in the H. microstoma v.2 genome assembly, demonstrating that the transcriptome profiles captured a high percentage of predicted genes. Contrasts made between the transcriptomes of Larvae and whole, adult worms, and between the Scolex-Neck, mature strobila and gravid strobila, resulted in 4.5-30% of the genes determined to be differentially expressed. Among these, we identified 190 unique GOI up-regulated in one or more contrasts, including a large range of zinc finger, homeobox and other transcription factors, components of Wnt, Notch, Hedgehog and TGF-β/BMP signalling, and post-transcriptional regulators (e.g. Boule, Pumilio). Heatmap clusterings based on overall expression and on select groups of genes representing 'signals' and 'switches' showed that expression in the Scolex-Neck region is more similar to that of Larvae than to the mature or gravid regions of the adult worm, which was further reflected in large overlap of up-regulated GOI. CONCLUSIONS Spatial expression analyses in Larvae and adult worms corroborated inferences made from quantitative RNA-seq data and in most cases indicated consistency with canonical roles of the genes in other animals, including free-living flatworms. Recapitulation of developmental factors up-regulated during larval metamorphosis suggests that strobilar growth involves many of the same underlying gene regulatory networks despite the significant disparity in developmental outcomes. The majority of genes identified were investigated in tapeworms for the first time, setting the stage for advancing our understanding of developmental genetics in an important group of flatworm parasites.
Collapse
Affiliation(s)
- Peter D. Olson
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Magdalena Zarowiecki
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
- Parasite Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Katherine James
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Andrew Baillie
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Georgie Bartl
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Phil Burchell
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Azita Chellappoo
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Francesca Jarero
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Li Ying Tan
- Division of Parasites and Vectors, Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Nancy Holroyd
- Parasite Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Matt Berriman
- Parasite Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| |
Collapse
|
34
|
Characterizing the role of SWI/SNF-related chromatin remodeling complexes in planarian regeneration and stem cell function. Stem Cell Res 2018; 32:91-103. [DOI: 10.1016/j.scr.2018.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/18/2018] [Accepted: 09/06/2018] [Indexed: 11/21/2022] Open
|
35
|
Arboleda E, Hartenstein V, Martinez P, Reichert H, Sen S, Sprecher S, Bailly X. An Emerging System to Study Photosymbiosis, Brain Regeneration, Chronobiology, and Behavior: The Marine Acoel Symsagittifera roscoffensis. Bioessays 2018; 40:e1800107. [PMID: 30151860 DOI: 10.1002/bies.201800107] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/23/2018] [Indexed: 01/23/2023]
Abstract
The acoel worm Symsagittifera roscoffensis, an early offshoot of the Bilateria and the only well-studied marine acoel that lives in a photosymbiotic relationship, exhibits a centralized nervous system, brain regeneration, and a wide repertoire of complex behaviors such as circatidal rhythmicity, photo/geotaxis, and social interactions. While this animal can be collected by the thousands and is studied historically, significant progress is made over the last decade to develop it as an emerging marine model. The authors here present the feasibility of culturing it in the laboratory and describe the progress made on different areas, including genomic and tissue architectures, highlighting the associated challenges. In light of these developments, and on the ability to access abundant synchronized embryos, the authors put forward S. roscoffensis as a marine system to revisit questions in the areas of photosymbiosis, regeneration, chronobiology, and the study of complex behaviors from a molecular and evolutionary perspective.
Collapse
Affiliation(s)
- Enrique Arboleda
- Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | | | - Pedro Martinez
- Institut Català de Recerca i EstudisAvancats (ICREA), Passeig de Lluís Companys, 23, 08010 Barcelona, Spain
| | - Heinrich Reichert
- Departement de Biologie Universite de Fribourg, 1700 Fribourg, Switzerland
| | - Sonia Sen
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, Eugene, OR 97403
| | | | - Xavier Bailly
- CNRS, Station Biologique de Roscoff, 29680 Roscoff, France
| |
Collapse
|
36
|
Swapna LS, Molinaro AM, Lindsay-Mosher N, Pearson BJ, Parkinson J. Comparative transcriptomic analyses and single-cell RNA sequencing of the freshwater planarian Schmidtea mediterranea identify major cell types and pathway conservation. Genome Biol 2018; 19:124. [PMID: 30143032 PMCID: PMC6109357 DOI: 10.1186/s13059-018-1498-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 08/01/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND In the Lophotrochozoa/Spiralia superphylum, few organisms have as high a capacity for rapid testing of gene function and single-cell transcriptomics as the freshwater planaria. The species Schmidtea mediterranea in particular has become a powerful model to use in studying adult stem cell biology and mechanisms of regeneration. Despite this, systematic attempts to define gene complements and their annotations are lacking, restricting comparative analyses that detail the conservation of biochemical pathways and identify lineage-specific innovations. RESULTS In this study we compare several transcriptomes and define a robust set of 35,232 transcripts. From this, we perform systematic functional annotations and undertake a genome-scale metabolic reconstruction for S. mediterranea. Cross-species comparisons of gene content identify conserved, lineage-specific, and expanded gene families, which may contribute to the regenerative properties of planarians. In particular, we find that the TRAF gene family has been greatly expanded in planarians. We further provide a single-cell RNA sequencing analysis of 2000 cells, revealing both known and novel cell types defined by unique signatures of gene expression. Among these are a novel mesenchymal cell population as well as a cell type involved in eye regeneration. Integration of our metabolic reconstruction further reveals the extent to which given cell types have adapted energy and nucleotide biosynthetic pathways to support their specialized roles. CONCLUSIONS In general, S. mediterranea displays a high level of gene and pathway conservation compared with other model systems, rendering it a viable model to study the roles of these pathways in stem cell biology and regeneration.
Collapse
Affiliation(s)
| | - Alyssa M Molinaro
- Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Nicole Lindsay-Mosher
- Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Bret J Pearson
- Hospital for Sick Children, Toronto, ON, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada. .,Ontario Institute for Cancer Research, Toronto, ON, Canada.
| | - John Parkinson
- Hospital for Sick Children, Toronto, ON, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada. .,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
| |
Collapse
|
37
|
Birkholz TR, Van Huizen AV, Beane WS. Staying in shape: Planarians as a model for understanding regenerative morphology. Semin Cell Dev Biol 2018; 87:105-115. [PMID: 29738883 DOI: 10.1016/j.semcdb.2018.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/23/2018] [Accepted: 04/30/2018] [Indexed: 01/18/2023]
Abstract
A key requirement of tissue/organ regeneration is the ability to induce appropriate shape in situ. Regenerated structures need to be integrated with pre-existing ones, through the combined regulation of new tissue growth and the scaling of surrounding tissues. This requires a tightly coordinated control of individual cell functions such as proliferation and stem cell differentiation. While great strides have been made in elucidating cell growth and differentiation mechanisms, how overall shape is generated during regeneration remains unknown. This is because a significant gap remains in our understanding of how cell behaviors are coordinated at the level of tissues and organs. The highly regenerative planarian flatworm has emerged as an important model for defining and understanding regenerative shape mechanisms. This review provides an overview of the main processes known to regulate tissue and animal shape during planarian regeneration: adult stem cell regulation, the reestablishment of body axes, tissue remodeling in pre-existing structures, organ scaling and the maintenance of body proportion, and the bioelectrical regulation of animal morphology. In order for the field to move forward, it will be necessary to identify shape mutants as a means to uncover the molecular mechanisms that synchronize all these separate processes to produce the worm's final regenerative shape. This knowledge will also aid efforts to define the mechanisms that control the termination of regenerative processes.
Collapse
Affiliation(s)
- Taylor R Birkholz
- Department of Biological Sciences, Western Michigan University, 1903 W. Michigan Avenue, Kalamazoo, MI, 49008, USA
| | - Alanna V Van Huizen
- Department of Biological Sciences, Western Michigan University, 1903 W. Michigan Avenue, Kalamazoo, MI, 49008, USA
| | - Wendy S Beane
- Department of Biological Sciences, Western Michigan University, 1903 W. Michigan Avenue, Kalamazoo, MI, 49008, USA.
| |
Collapse
|
38
|
De Miguel-Bonet MDM, Ahad S, Hartenstein V. Role of neoblasts in the patterned postembryonic growth of the platyhelminth Macrostomum lignano. NEUROGENESIS 2018; 5:e14699441-e14699449. [PMID: 30083565 DOI: 10.1080/23262133.2018.1469944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 03/29/2018] [Accepted: 04/20/2018] [Indexed: 10/17/2022]
Abstract
Neoblasts are motile pluripotent stem cells unique to the flatworm phyla Platyhelminthes and Acoela. The role of neoblasts in tissue regeneration has received much attention in recent studies. Here we review data pertinent to the structure and embryonic origin of these stem cells, and their participation in normal cell turnover. Next, we present data proving that neoblasts also account for the addition of cells during postembryonic growth. Bromodeoxyuridine (BrdU) pulse chase experiments demonstrate that the incorporation of neoblast-derived cells into the different tissues of the juvenile worm follows a stereotyped pattern, whereby cells within the parenchymal layer (muscle, gland) incorporate new cells most rapidly, followed by the epidermal domain surrounding the mouth, dorsal epidermis, and, lastly, the nervous system.
Collapse
Affiliation(s)
| | - Sally Ahad
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
| |
Collapse
|
39
|
The role of the EGFR signaling pathway in stem cell differentiation during planarian regeneration and homeostasis. Semin Cell Dev Biol 2018; 87:45-57. [PMID: 29775660 DOI: 10.1016/j.semcdb.2018.05.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 05/07/2018] [Accepted: 05/14/2018] [Indexed: 12/25/2022]
Abstract
Cell signaling is essential for cells to adequately respond to their environment. One of the most evolutionarily conserved signaling pathways is that of the epidermal growth factor receptor (EGFR). Transmembrane receptors with intracellular tyrosine kinase activity are activated by the binding of their corresponding ligands. This in turn activates a wide variety of intracellular cascades and induces the up- or downregulation of target genes, leading to a specific cellular response. Freshwater planarians are an excellent model in which to study the role of cell signaling in the context of stem-cell based regeneration. Owing to the presence of a population of pluripotent stem cells called neoblasts, these animals can regenerate the entire organism from a tiny piece of the body. Here, we review the current state of knowledge of the planarian EGFR pathway. We describe the main components of the pathway and their functions in other animals, and focus in particular on receptors and ligands identified in the planarian Schmidtea mediterranea. Moreover, we summarize current data on the function of some of these components during planarian regeneration and homeostasis. We hypothesize that the EGFR pathway may act as a key regulator of the terminal differentiation of distinct populations of lineage-committed progenitors.
Collapse
|
40
|
DNA damage and tissue repair: What we can learn from planaria. Semin Cell Dev Biol 2018; 87:145-159. [PMID: 29727725 DOI: 10.1016/j.semcdb.2018.04.013] [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: 01/30/2018] [Revised: 04/22/2018] [Accepted: 04/30/2018] [Indexed: 12/21/2022]
Abstract
Faithful renewal of aging and damaged tissues is central to organismal lifespan. Stem cells (SCs) generate the cellular progeny that replenish adult tissues across the body but this task becomes increasingly compromised over time. The age related decline in SC-mediated tissue maintenance is a multifactorial event that commonly affects genome integrity. The presence of DNA damage in SCs that are under continuous demand to divide poses a great risk for age-related disorders such as cancer. However, performing analysis of SCs with genomic instability and the DNA damage response during tissue renewal present significant challenges. Here we introduce an alternative experimental system based on the planaria flatworm Schmidtea mediterranea to address at the organismal level studies intersecting SC-mediated tissue renewal in the presence of genomic instability. Planaria have abundant SCs (neoblasts) that maintain high rates of cellular turnover and a variety of molecular tools have been developed to induce DNA damage and dissect how neoblasts respond to this stressor. S. mediterranea displays high evolutionary conservation of DNA repair mechanisms and signaling pathways regulating adult SCs. We describe genetically induced-DNA damage models and highlight body-wide signals affecting cellular decisions such as survival, proliferation, and death in the presence of genomic instability. We also discuss transcriptomic changes in the DNA damage response during injury repair and propose DNA repair as key component of tissue regeneration. Additional studies using planaria will provide insights about mechanisms regulating survival and growth of cells with DNA damage during tissue renewal and regeneration.
Collapse
|
41
|
Rossi L, Salvetti A. Planarian stem cell niche, the challenge for understanding tissue regeneration. Semin Cell Dev Biol 2018. [PMID: 29534938 DOI: 10.1016/j.semcdb.2018.03.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Stem cell fate depends on surrounding microenvironment, the so called niche. For this reason, understanding stem cell niche is one of the most challenging target in cell biology field and need to be unraveled with in vivo studies. Planarians offer this unique opportunity, as their stem cells, the neoblasts, are abundant, highly characterized and genetically modifiable by RNA interference in alive animals. However, despite impressive advances have been done in the understanding planarian stem cells and regeneration, only a few information is available in defining signals from differentiated tissues, which affect neoblast stemness and fate. Here, we review on molecular factors that have been found activated in differentiated tissues and directly or indirectly affect neoblast behavior, and we suggest future directions for unravelling this challenge in understanding planarian stem cells.
Collapse
Affiliation(s)
- Leonardo Rossi
- Departement of Clinical and Experimental Medicine, Unit of Experimental Biology and Genetics, University of Pisa, Via Volta 4 Pisa, Italy
| | - Alessandra Salvetti
- Departement of Clinical and Experimental Medicine, Unit of Experimental Biology and Genetics, University of Pisa, Via Volta 4 Pisa, Italy.
| |
Collapse
|
42
|
Fields C, Levin M. Are Planaria Individuals? What Regenerative Biology is Telling Us About the Nature of Multicellularity. Evol Biol 2018. [DOI: 10.1007/s11692-018-9448-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
43
|
Lai AG, Aboobaker AA. EvoRegen in animals: Time to uncover deep conservation or convergence of adult stem cell evolution and regenerative processes. Dev Biol 2018; 433:118-131. [PMID: 29198565 DOI: 10.1016/j.ydbio.2017.10.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 01/08/2023]
Abstract
How do animals regenerate specialised tissues or their entire body after a traumatic injury, how has this ability evolved and what are the genetic and cellular components underpinning this remarkable feat? While some progress has been made in understanding mechanisms, relatively little is known about the evolution of regenerative ability. Which elements of regeneration are due to lineage specific evolutionary novelties or have deeply conserved roots within the Metazoa remains an open question. The renaissance in regeneration research, fuelled by the development of modern functional and comparative genomics, now enable us to gain a detailed understanding of both the mechanisms and evolutionary forces underpinning regeneration in diverse animal phyla. Here we review existing and emerging model systems, with the focus on invertebrates, for studying regeneration. We summarize findings across these taxa that tell us something about the evolution of adult stem cell types that fuel regeneration and the growing evidence that many highly regenerative animals harbor adult stem cells with a gene expression profile that overlaps with germline stem cells. We propose a framework in which regenerative ability broadly evolves through changes in the extent to which stem cells generated through embryogenesis are maintained into the adult life history.
Collapse
Affiliation(s)
- Alvina G Lai
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - A Aziz Aboobaker
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.
| |
Collapse
|
44
|
Strand NS, Allen JM, Ghulam M, Taylor MR, Munday RK, Carrillo M, Movsesyan A, Zayas RM. Dissecting the function of Cullin-RING ubiquitin ligase complex genes in planarian regeneration. Dev Biol 2018; 433:210-217. [PMID: 29291974 DOI: 10.1016/j.ydbio.2017.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/25/2017] [Accepted: 10/11/2017] [Indexed: 12/26/2022]
Abstract
The ubiquitin system plays a role in nearly every aspect of eukaryotic cell biology. The enzymes responsible for transferring ubiquitin onto specific substrates are the E3 ubiquitin ligases, a large and diverse family of proteins, for which biological roles and target substrates remain largely undefined. Studies using model organisms indicate that ubiquitin signaling mediates key steps in developmental processes and tissue regeneration. Here, we used the freshwater planarian, Schmidtea mediterranea, to investigate the role of Cullin-RING ubiquitin ligase (CRL) complexes in stem cell regulation during regeneration. We identified six S. mediterranea cullin genes, and used RNAi to uncover roles for homologs of Cullin-1, -3 and -4 in planarian regeneration. The cullin-1 RNAi phenotype included defects in blastema formation, organ regeneration, lesions, and lysis. To further investigate the function of cullin-1-mediated cellular processes in planarians, we examined genes encoding the adaptor protein Skp1 and F-box substrate-recognition proteins that are predicted to partner with Cullin-1. RNAi against skp1 resulted in phenotypes similar to cullin-1 RNAi, and an RNAi screen of the F-box genes identified 19 genes that recapitulated aspects of cullin-1 RNAi, including ones that in mammals are involved in stem cell regulation and cancer biology. Our data provides evidence that CRLs play discrete roles in regenerative processes and provide a platform to investigate how CRLs regulate stem cells in vivo.
Collapse
Affiliation(s)
- Nicholas S Strand
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - John M Allen
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Mahjoobah Ghulam
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Matthew R Taylor
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Roma K Munday
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Melissa Carrillo
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Artem Movsesyan
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Ricardo M Zayas
- Department of Biology, San Diego State University, San Diego, CA 92182, USA.
| |
Collapse
|
45
|
Cassella L, Salvetti A, Iacopetti P, Ippolito C, Ghezzani C, Gimenez G, Ghigo E, Rossi L. Putrescine independent wound response phenotype is produced by ODC-like RNAi in planarians. Sci Rep 2017; 7:9736. [PMID: 28851936 PMCID: PMC5574924 DOI: 10.1038/s41598-017-09567-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 07/26/2017] [Indexed: 01/18/2023] Open
Abstract
Despite increasing evidence indicates polyamines as a convergence point for signaling pathways, including cell growth and differentiation, a unifying concept to interpret their role is still missing. The activity of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, is tightly regulated by a complex molecular machinery, and the demonstration of the existence of multiple ODC paralogs, lacking decarboxylation activity, suggests additional layers of complexity to the intricate ODC regulatory pathway. Because of their extraordinary regenerative abilities and abundance of stem cells, planarians have potential to contribute to our understanding of polyamine function in an in vivo context. We undertook a study on ODC function in planarians and we found six planarian ODCs (ODC1-6). Five out of six ODC homologs carry substitutions of key aminoacids for enzymatic activity, which makes them theoretically unable to decarboxylate ornithine. Silencing of ODC5 and 6 produced a complex phenotype, by prompting animals to an aberrant response, following chronic injury without tissue removal. Phenotype is neither rescued by putrescine, nor mimicked by difluoromethylornithine treatment. Moreover, the co-silencing of other genes of the ODC regulatory pathway did not modulate phenotype outcome or severity, thus suggesting that the function/s of these ODC-like proteins might be unrelated to decarboxylase activity and putrescine production.
Collapse
Affiliation(s)
- Lucia Cassella
- Department of Clinical and Experimental Medicine, University of Pisa, via Volta 4, 56126, Pisa, Italy
| | - Alessandra Salvetti
- Department of Clinical and Experimental Medicine, University of Pisa, via Volta 4, 56126, Pisa, Italy
| | - Paola Iacopetti
- Department of Clinical and Experimental Medicine, University of Pisa, via Volta 4, 56126, Pisa, Italy
| | - Chiara Ippolito
- Department of Clinical and Experimental Medicine, University of Pisa, via Volta 4, 56126, Pisa, Italy
| | - Claudio Ghezzani
- Department of Clinical and Experimental Medicine, University of Pisa, via Volta 4, 56126, Pisa, Italy
| | - Gregory Gimenez
- Otago Genomics & Bioinformatics Facility, Department of Biochemistry, University of Otago, PO Box 56, 710 Cumberland Street, Dunedin, 9054, New Zealand
| | - Eric Ghigo
- CNRS UMR 7278, IRD198, INSERM U1095, APHM, Institut Hospitalier Universitaire Méditerranée-Infection, Aix-Marseille Université, 19-21 Bd Jean Moulin, 13385, Marseille Cedex 05, France
| | - Leonardo Rossi
- Department of Clinical and Experimental Medicine, University of Pisa, via Volta 4, 56126, Pisa, Italy.
| |
Collapse
|
46
|
Busengdal H, Rentzsch F. Unipotent progenitors contribute to the generation of sensory cell types in the nervous system of the cnidarian Nematostella vectensis. Dev Biol 2017; 431:59-68. [PMID: 28827097 DOI: 10.1016/j.ydbio.2017.08.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 08/08/2017] [Accepted: 08/17/2017] [Indexed: 11/18/2022]
Abstract
Nervous systems often consist of a large number of different types of neurons which are generated from neural stem and progenitor cells by a series of symmetric and asymmetric divisions. The origin and early evolution of these neural progenitor systems is not well understood. Here we use a cnidarian model organism, Nematostella vectensis, to gain insight into the generation of neural cell type diversity in a non-bilaterian animal. We identify NvFoxQ2d as a transcription factor that is expressed in a population of spatially restricted, proliferating ectodermal cells that are derived from NvSoxB(2)-expressing neural progenitor cells. Using a transgenic reporter line we show that the NvFoxQ2d cells undergo a terminal, symmetric division to generate a morphologically homogeneous population of putative sensory cells. The abundance of these cells, but not their proliferation status is affected by treatment with the γ-secretase inhibitor DAPT, suggesting regulation by Notch signalling. Our data suggest that intermediate progenitor cells and symmetric divisions contribute to the formation of the seemingly simple nervous system of a sea anemone.
Collapse
Affiliation(s)
- Henriette Busengdal
- Sars Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, 5006 Bergen, Norway
| | - Fabian Rentzsch
- Sars Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt. 55, 5006 Bergen, Norway.
| |
Collapse
|
47
|
Voura EB, Montalvo MJ, Dela Roca KT, Fisher JM, Defamie V, Narala SR, Khokha R, Mulligan ME, Evans CA. Planarians as models of cadmium-induced neoplasia provide measurable benchmarks for mechanistic studies. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 142:544-554. [PMID: 28482323 DOI: 10.1016/j.ecoenv.2017.04.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 04/02/2017] [Accepted: 04/19/2017] [Indexed: 06/07/2023]
Abstract
Bioassays of planarian neoplasia highlight the potential of these organisms as useful standards to assess whether environmental toxins such as cadmium promote tumorigenesis. These studies complement other investigations into the exceptional healing and regeneration of planarians - processes that are driven by a population of active stem cells, or neoblasts, which are likely transformed during planarian tumor growth. Our goal was to determine if planarian tumorigenesis assays are amenable to mechanistic studies of cadmium carcinogenesis. To that end we demonstrate, by examining both counts of cell populations by size, and instances of mitosis, that the activity of the stem cell population can be monitored. We also provide evidence that specific biomodulators can affect the potential of planarian neoplastic growth, in that an inhibitor of metalloproteinases effectively blocked the development of the lesions. From these results, we infer that neoblast activity does respond to cadmium-induced tumor growth, and that metalloproteinases are required for the progression of cancer in the planarian.
Collapse
Affiliation(s)
- Evelyn B Voura
- School of Science, Technology and Health Studies, Morrisville State College, 80 Eaton Street, Morrisville, New York 13408, USA.
| | - Melissa J Montalvo
- Department of Math and Science, Dominican College, 470 Western Highway South, Orangeburg, New York 10962, USA
| | - Kevin T Dela Roca
- Department of Math and Science, Dominican College, 470 Western Highway South, Orangeburg, New York 10962, USA
| | - Julia M Fisher
- Colgate University, 13 Oak Drive, Hamilton, New York 13346, USA
| | - Virginie Defamie
- Ontario Cancer Institute, University Health Network, University of Toronto, 101 College Street, Toronto, Ontario M5G 1L7, Canada
| | - Swami R Narala
- Ontario Cancer Institute, University Health Network, University of Toronto, 101 College Street, Toronto, Ontario M5G 1L7, Canada
| | - Rama Khokha
- Ontario Cancer Institute, University Health Network, University of Toronto, 101 College Street, Toronto, Ontario M5G 1L7, Canada
| | - Margaret E Mulligan
- Department of Math and Science, Dominican College, 470 Western Highway South, Orangeburg, New York 10962, USA
| | - Colleen A Evans
- Department of Math and Science, Dominican College, 470 Western Highway South, Orangeburg, New York 10962, USA
| |
Collapse
|
48
|
Brown DDR, Pearson BJ. A Brain Unfixed: Unlimited Neurogenesis and Regeneration of the Adult Planarian Nervous System. Front Neurosci 2017; 11:289. [PMID: 28588444 PMCID: PMC5441136 DOI: 10.3389/fnins.2017.00289] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/08/2017] [Indexed: 11/25/2022] Open
Abstract
Powerful genetic tools in classical laboratory models have been fundamental to our understanding of how stem cells give rise to complex neural tissues during embryonic development. In contrast, adult neurogenesis in our model systems, if present, is typically constrained to one or a few zones of the adult brain to produce a limited subset of neurons leading to the dogma that the brain is primarily fixed post-development. The freshwater planarian (flatworm) is an invertebrate model system that challenges this dogma. The planarian possesses a brain containing several thousand neurons with very high rates of cell turnover (homeostasis), which can also be fully regenerated de novo from injury in just 7 days. Both homeostasis and regeneration depend on the activity of a large population of adult stem cells, called neoblasts, throughout the planarian body. Thus, much effort has been put forth to understand how the flatworm can continually give rise to the diversity of cell types found in the adult brain. Here we focus on work using single-cell genomics and functional analyses to unravel the cellular hierarchies from stem cell to neuron. In addition, we will review what is known about how planarians utilize developmental signaling to maintain proper tissue patterning, homeostasis, and cell-type diversity in their brains. Together, planarians are a powerful emerging model system to study the dynamics of adult neurogenesis and regeneration.
Collapse
Affiliation(s)
- David D R Brown
- Program in Developmental and Stem Cell Biology, The Hospital for Sick ChildrenToronto, ON, Canada.,Department of Molecular Genetics, University of TorontoToronto, ON, Canada
| | - Bret J Pearson
- Program in Developmental and Stem Cell Biology, The Hospital for Sick ChildrenToronto, ON, Canada.,Department of Molecular Genetics, University of TorontoToronto, ON, Canada.,Ontario Institute for Cancer ResearchToronto, ON, Canada
| |
Collapse
|
49
|
Ross KG, Currie KW, Pearson BJ, Zayas RM. Nervous system development and regeneration in freshwater planarians. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2017; 6. [DOI: 10.1002/wdev.266] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/10/2017] [Accepted: 01/20/2017] [Indexed: 01/22/2023]
Affiliation(s)
- Kelly G. Ross
- Department of Biology San Diego State University San Diego CA USA
| | - Ko W. Currie
- Program in Developmental and Stem Cell Biology The Hospital for Sick Children Toronto Canada
- Department of Molecular Genetics University of Toronto Toronto Canada
- Ontario Institute for Cancer Research Toronto Canada
| | - Bret J. Pearson
- Program in Developmental and Stem Cell Biology The Hospital for Sick Children Toronto Canada
- Department of Molecular Genetics University of Toronto Toronto Canada
- Ontario Institute for Cancer Research Toronto Canada
| | - Ricardo M. Zayas
- Department of Biology San Diego State University San Diego CA USA
| |
Collapse
|
50
|
Koziol U. Evolutionary developmental biology (evo-devo) of cestodes. Exp Parasitol 2016; 180:84-100. [PMID: 27939766 DOI: 10.1016/j.exppara.2016.12.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/15/2016] [Accepted: 12/05/2016] [Indexed: 12/12/2022]
Abstract
Cestodes (tapeworms) have complex adaptations to their obligatory parasitic life-style. Among these adaptations, they show many evolutionary innovations in their development, including complex life-cycles with multiple hosts and life-stages, several independent origins of asexual reproduction, and the evolution of segmentation as a mean to generate massive reproductive output. Therefore, cestodes offer many opportunities for the investigation of the evolutionary origins of developmental novelties (evo-devo). However, cestodes have not been exploited as major models for evo-devo research due to the considerable technical difficulties involved in their study. In this review, a panoramic view is given of classical aspects, methods and hypothesis of cestode development, together with recent advances in phylogenetics, genomics, culture methods, and comparative analysis of cestode gene expression. Together with the availability of powerful models for related free-living flatworms, these developments should encourage the incorporation of these fascinating parasites into the first-line of evo-devo research.
Collapse
Affiliation(s)
- Uriel Koziol
- Sección Bioquímica, Facultad de Ciencias, Universidad de la República, Uruguay.
| |
Collapse
|