1
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Lee JR, Boothe T, Mauksch C, Thommen A, Rink JC. Epidermal turnover in the planarian Schmidtea mediterranea involves basal cell extrusion and intestinal digestion. Cell Rep 2024; 43:114305. [PMID: 38906148 DOI: 10.1016/j.celrep.2024.114305] [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: 11/06/2023] [Revised: 03/21/2024] [Accepted: 05/15/2024] [Indexed: 06/23/2024] Open
Abstract
Planarian flatworms undergo continuous internal turnover, wherein old cells are replaced by the division progeny of adult pluripotent stem cells (neoblasts). How cell turnover is carried out at the organismal level remains an intriguing question in planarians and other systems. While previous studies have predominantly focused on neoblast proliferation, little is known about the processes that mediate cell loss during tissue homeostasis. Here, we use the planarian epidermis as a model to study the mechanisms of cell removal. We established a covalent dye-labeling assay and image analysis pipeline to quantify the cell turnover rate in the planarian epidermis. Our findings indicate that the ventral epidermis is highly dynamic and epidermal cells undergo internalization via basal extrusion, followed by a relocation toward the intestine and ultimately digestion by intestinal phagocytes. Overall, our study reveals a complex homeostatic process of cell clearance that may generally allow planarians to catabolize their own cells.
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Affiliation(s)
- Jun-Ru Lee
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany; Graduate Center for Neurosciences, Biophysics, and Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
| | - Tobias Boothe
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - Clemens Mauksch
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - Albert Thommen
- Cancer Metabolism Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Jochen C Rink
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany; Faculty of Biology and Psychology, Georg-August-University, Göttingen, Germany.
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2
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Yu X, Zhou J, Ye W, Xu J, Li R, Huang L, Chai Y, Wen M, Xu S, Zhou Y. Time-course swRNA-seq uncovers a hierarchical gene regulatory network in controlling the response-repair-remodeling after wounding. Commun Biol 2024; 7:694. [PMID: 38844830 PMCID: PMC11156874 DOI: 10.1038/s42003-024-06352-w] [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: 02/26/2024] [Accepted: 05/17/2024] [Indexed: 06/09/2024] Open
Abstract
Wounding initiates intricate responses crucial for tissue repair and regeneration. Yet, the gene regulatory networks governing wound healing remain poorly understood. Here, employing single-worm RNA sequencing (swRNA-seq) across 12 time-points, we delineated a three-stage wound repair process in C. elegans: response, repair, and remodeling. Integrating diverse datasets, we constructed a dynamic regulatory network comprising 241 transcription regulators and their inferred targets. We identified potentially seven autoregulatory TFs and five cross-autoregulatory loops involving pqm-1 and jun-1. We revealed that TFs might interact with chromatin factors and form TF-TF combinatory modules via intrinsically disordered regions to enhance response robustness. We experimentally validated six regulators functioning in transcriptional and translocation-dependent manners. Notably, nhr-76, daf-16, nhr-84, and oef-1 are potentially required for efficient repair, while elt-2 may act as an inhibitor. These findings elucidate transcriptional responses and hierarchical regulatory networks during C. elegans wound repair, shedding light on mechanisms underlying tissue repair and regeneration.
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Affiliation(s)
- Xinghai Yu
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA Institute, Hubei Key Laboratory of Cell Homeostasis, Wuhan University, Wuhan, 430072, China
| | - Jinghua Zhou
- Center for Stem Cell and Regenerative Medicine and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Wenkai Ye
- Center for Stem Cell and Regenerative Medicine and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jingxiu Xu
- Center for Stem Cell and Regenerative Medicine and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Rui Li
- Institute of Hydrobiology, Chinese Academy of Science, Wuhan, 430072, China
| | - Li Huang
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA Institute, Hubei Key Laboratory of Cell Homeostasis, Wuhan University, Wuhan, 430072, China
| | - Yi Chai
- The Zhejiang University-University of Edinburgh Institute, 718 East Haizhou Rd., Haining, Zhejiang, 314400, China
| | - Miaomiao Wen
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA Institute, Hubei Key Laboratory of Cell Homeostasis, Wuhan University, Wuhan, 430072, China
| | - Suhong Xu
- Center for Stem Cell and Regenerative Medicine and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.
- The Zhejiang University-University of Edinburgh Institute, 718 East Haizhou Rd., Haining, Zhejiang, 314400, China.
| | - Yu Zhou
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, RNA Institute, Hubei Key Laboratory of Cell Homeostasis, Wuhan University, Wuhan, 430072, China.
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430072, China.
- State Key Laboratory of Virology, Wuhan University, Wuhan, 430072, China.
- Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China.
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3
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Shimada M, Hayakawa MM, Suzaki T, Ishida H. Morphological reconstruction during cell regeneration in the ciliate Spirostomum ambiguum. Eur J Protistol 2024; 94:126079. [PMID: 38593565 DOI: 10.1016/j.ejop.2024.126079] [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: 11/17/2023] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/11/2024]
Abstract
When the ciliate Spirostomum ambiguum is transected into two pieces, both fragments regenerate and proliferate. In the anterior fragments, which have lost their contractile vacuoles due to transection, new contractile vacuoles were formed at their posterior ends in a few minutes. When the cells were cut into three pieces, new contractile vacuoles were formed in the anterior and middle fragments, both at their posterior ends. Thus, the anterior-posterior axis of S. ambiguum was maintained after transection. Morphological repair, including the formation of the contractile vacuole, was also observed when only the anteriormost portion was transected to cut out a small fragment that did not contain part of the macronucleus. Scanning electron microscopy was performed to observe changes in the shape of the cleavage surface of S. ambiguum during the wound healing process. Within minutes after cutting, the cut surface was covered with a cilia-free membrane, preventing leakage of cytoplasmic contents. The surface of the cut area then rounded with time and was covered with cilia, completing the repair of the cut area in about one day.
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Affiliation(s)
- Maho Shimada
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu-cho, Matsue 690-8504, Japan
| | - Masashi M Hayakawa
- Graduate School of Human Sciences, Osaka University, 1-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toshinobu Suzaki
- Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Hideki Ishida
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu-cho, Matsue 690-8504, Japan.
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4
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Nanes Sarfati D, Xue Y, Song ES, Byrne A, Le D, Darmanis S, Quake SR, Burlacot A, Sikes J, Wang B. Coordinated wound responses in a regenerative animal-algal holobiont. Nat Commun 2024; 15:4032. [PMID: 38740753 DOI: 10.1038/s41467-024-48366-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
Animal regeneration involves coordinated responses across cell types throughout the animal body. In endosymbiotic animals, whether and how symbionts react to host injury and how cellular responses are integrated across species remain unexplored. Here, we study the acoel Convolutriloba longifissura, which hosts symbiotic Tetraselmis sp. green algae and can regenerate entire bodies from tissue fragments. We show that animal injury causes a decline in the photosynthetic efficiency of the symbiotic algae, alongside two distinct, sequential waves of transcriptional responses in acoel and algal cells. The initial algal response is characterized by the upregulation of a cohort of photosynthesis-related genes, though photosynthesis is not necessary for regeneration. A conserved animal transcription factor, runt, is induced after injury and required for acoel regeneration. Knockdown of Cl-runt dampens transcriptional responses in both species and further reduces algal photosynthetic efficiency post-injury. Our results suggest that the holobiont functions as an integrated unit of biological organization by coordinating molecular networks across species through the runt-dependent animal regeneration program.
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Affiliation(s)
| | - Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Eun Sun Song
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | | | - Daniel Le
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | | | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Adrien Burlacot
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - James Sikes
- Department of Biology, University of San Francisco, San Francisco, CA, USA.
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
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5
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King HO, Owusu-Boaitey KE, Fincher CT, Reddien PW. A transcription factor atlas of stem cell fate in planarians. Cell Rep 2024; 43:113843. [PMID: 38401119 PMCID: PMC11232438 DOI: 10.1016/j.celrep.2024.113843] [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: 04/05/2023] [Revised: 12/05/2023] [Accepted: 02/06/2024] [Indexed: 02/26/2024] Open
Abstract
Whole-body regeneration requires the ability to produce the full repertoire of adult cell types. The planarian Schmidtea mediterranea contains over 125 cell types, which can be regenerated from a stem cell population called neoblasts. Neoblast fate choice can be regulated by the expression of fate-specific transcription factors (FSTFs). How fate choices are made and distributed across neoblasts versus their post-mitotic progeny remains unclear. We used single-cell RNA sequencing to systematically map fate choices made in S/G2/M neoblasts and, separately, in their post-mitotic progeny that serve as progenitors for all adult cell types. We defined transcription factor expression signatures associated with all detected fates, identifying numerous new progenitor classes and FSTFs that regulate them. Our work generates an atlas of stem cell fates with associated transcription factor signatures for most cell types in a complete adult organism.
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Affiliation(s)
- Hunter O King
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, 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
| | - Christopher T Fincher
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Peter W Reddien
- Howard Hughes Medical Institute, Chevy Chase, MD, USA; Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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6
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Mitchell DG, Edgar A, Mateu JR, Ryan JF, Martindale MQ. The ctenophore Mnemiopsis leidyi deploys a rapid injury response dating back to the last common animal ancestor. Commun Biol 2024; 7:203. [PMID: 38374160 PMCID: PMC10876535 DOI: 10.1038/s42003-024-05901-7] [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: 06/29/2023] [Accepted: 02/08/2024] [Indexed: 02/21/2024] Open
Abstract
Regenerative potential is widespread but unevenly distributed across animals. However, our understanding of the molecular mechanisms underlying regenerative processes is limited to a handful of model organisms, restricting robust comparative analyses. Here, we conduct a time course of RNA-seq during whole body regeneration in Mnemiopsis leidyi (Ctenophora) to uncover gene expression changes that correspond with key events during the regenerative timeline of this species. We identified several genes highly enriched in this dataset beginning as early as 10 minutes after surgical bisection including transcription factors in the early timepoints, peptidases in the middle timepoints, and cytoskeletal genes in the later timepoints. We validated the expression of early response transcription factors by whole mount in situ hybridization, showing that these genes exhibited high expression in tissues surrounding the wound site. These genes exhibit a pattern of transient upregulation as seen in a variety of other organisms, suggesting that they may be initiators of an ancient gene regulatory network linking wound healing to the initiation of a regenerative response.
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Affiliation(s)
- Dorothy G Mitchell
- Whitney Laboratory for Marine Bioscience, University of Florida, Saint Augustine, FL, USA
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Allison Edgar
- Whitney Laboratory for Marine Bioscience, University of Florida, Saint Augustine, FL, USA
| | - Júlia Ramon Mateu
- Whitney Laboratory for Marine Bioscience, University of Florida, Saint Augustine, FL, USA
| | - Joseph F Ryan
- Whitney Laboratory for Marine Bioscience, University of Florida, Saint Augustine, FL, USA
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Mark Q Martindale
- Whitney Laboratory for Marine Bioscience, University of Florida, Saint Augustine, FL, USA.
- Department of Biology, University of Florida, Gainesville, FL, USA.
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7
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Wang KT, Tapper J, Adler CE. Purification of Planarian Stem Cells Using a Draq5-Based FACS Approach. Methods Mol Biol 2024; 2805:203-212. [PMID: 39008184 DOI: 10.1007/978-1-0716-3854-5_14] [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] [Indexed: 07/16/2024]
Abstract
Planarians are flatworms that have the remarkable ability to regenerate entirely new animals. This regenerative ability requires abundant adult stem cells called neoblasts, which are relatively small in size, sensitive to irradiation and the only proliferative cells in the animal. Despite the lack of cell surface markers, fluorescence-activated cell sorting (FACS) protocols have been developed to discriminate and isolate neoblasts, based on DNA content. Here, we describe a protocol that combines staining of far-red DNA dye Draq5, Calcein-AM and DAPI, along with a shortened processing time. This profiling strategy can be used to functionally characterize the neoblast population in pharmacologically-treated or gene knockdown animals. Highly purified neoblasts can be analyzed with downstream assays, such as in situ hybridization and RNA sequencing.
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Affiliation(s)
- Kuang-Tse Wang
- Department of Molecular Medicine, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Justin Tapper
- Department of Molecular Medicine, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Carolyn E Adler
- Department of Molecular Medicine, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA.
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8
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Wiggans M, Zhu SJ, Molinaro AM, Pearson BJ. The BAF chromatin remodeling complex licenses planarian stem cells access to ectodermal and mesodermal cell fates. BMC Biol 2023; 21:227. [PMID: 37864247 PMCID: PMC10589948 DOI: 10.1186/s12915-023-01730-y] [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: 02/09/2023] [Accepted: 10/10/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND The flatworm planarian, Schmidtea mediterranea, has a large population of adult stem cells (ASCs) that replace any cell type during tissue turnover or regeneration. How planarian ASCs (called neoblasts) manage self-renewal with the ability to produce daughter cells of different cell lineages (multipotency) is not well understood. Chromatin remodeling complexes ultimately control access to DNA regions of chromosomes and together with specific transcription factors determine whether a gene is transcribed in a given cell type. Previous work in planarians determined that RNAi of core components of the BAF chromatin remodeling complex, brg1 and smarcc2, caused increased ASCs and failed regeneration, but how these cellular defects arise at the level of gene regulation in neoblasts is unknown. RESULTS Here, we perform ATAC and RNA sequencing on purified neoblasts, deficient for the BAF complex subunits brg-1 and smarcc2. The data demonstrate that the BAF complex promotes chromatin accessibility and facilitates transcription at target loci, as in other systems. Interestingly, we find that the BAF complex enables access to genes known to be required for the generation of mesoderm- and ectoderm-derived lineages, including muscle, parenchymal cathepsin, neural, and epithelial lineages. BAF complex knockdowns result in disrupted differentiation into these cell lineages and functional consequences on planarian regeneration and tissue turnover. Notably, we did not detect a role for the BAF complex in neoblasts making endodermal lineages. CONCLUSIONS Our study provides functional insights into how the BAF complex contributes to cell fate decisions in planarian ASCs in vivo.
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Affiliation(s)
- Mallory Wiggans
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, M5G0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Shu Jun Zhu
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, M5G0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Alyssa M Molinaro
- Present address: 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.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada.
- Present address: Oregon Health & Science University, Portland, OR, 97239, USA.
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9
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Chen JJ, Lei K. The known, unknown, and unknown unknowns of cell-cell communication in planarian regeneration. Zool Res 2023; 44:981-992. [PMID: 37721107 PMCID: PMC10559094 DOI: 10.24272/j.issn.2095-8137.2023.044] [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: 06/02/2023] [Accepted: 09/11/2023] [Indexed: 09/19/2023] Open
Abstract
Planarians represent the most primitive bilateral triploblastic animals. Most planarian species exhibit mechanisms for whole-body regeneration, exemplified by the regeneration of their cephalic ganglion after complete excision. Given their robust whole-body regeneration capacity, planarians have been model organisms in regenerative research for more than 240 years. Advancements in research tools and techniques have progressively elucidated the mechanisms underlying planarian regeneration. Accurate cell-cell communication is recognized as a fundamental requirement for regeneration. In recent decades, mechanisms associated with such communication have been revealed at the cellular level. Notably, stem cells (neoblasts) have been identified as the source of all new cells during planarian homeostasis and regeneration. The interplay between neoblasts and somatic cells affects the identities and proportions of various tissues during homeostasis and regeneration. Here, this review outlines key discoveries regarding communication between stem cell compartments and other cell types in planarians, as well as the impact of communication on planarian regeneration. Additionally, this review discusses the challenges and potential directions of future planarian research, emphasizing the sustained impact of this field on our understanding of animal regeneration.
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Affiliation(s)
- Jia-Jia Chen
- School of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310030, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Kai Lei
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310030, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China. E-mail:
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10
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Akheralie Z, Scidmore TJ, Pearson BJ. aristaless-like homeobox-3 is wound induced and promotes a low-Wnt environment required for planarian head regeneration. Development 2023; 150:dev201777. [PMID: 37681295 PMCID: PMC10560571 DOI: 10.1242/dev.201777] [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: 03/13/2023] [Accepted: 08/30/2023] [Indexed: 09/09/2023]
Abstract
The planarian Schmidtea mediterranea is a well-established model of adult regeneration, which is dependent on a large population of adult stem cells called neoblasts. Upon amputation, planarians undergo transcriptional wounding programs and coordinated stem cell proliferation to give rise to missing tissues. Interestingly, the Wnt signaling pathway is key to guiding what tissues are regenerated, yet less known are the transcriptional regulators that ensure proper activation and timing of signaling pathway components. Here, we have identified an aristaless-like homeobox transcription factor, alx-3, that is enriched in a population of putative neural-fated progenitor cells at homeostasis, and is also upregulated in stem cells and muscle cells at anterior-facing wounds upon amputation. Knockdown of alx-3 results in failure of head regeneration and patterning defects in amputated tail fragments. alx-3 is required for the expression of several early wound-induced genes, including the Wnt inhibitor notum, which is required to establish anterior polarity during regeneration. Together, these findings reveal a role for alx-3 as an early wound-response transcriptional regulator in both muscle cells and stem cells that is required for anterior regeneration by promoting a low-Wnt environment.
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Affiliation(s)
- Zaleena Akheralie
- 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 M5S1A8, Canada
| | - Tanner J. Scidmore
- 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 M5S1A8, Canada
| | - 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 M5S1A8, Canada
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11
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Fan Y, Chai C, Li P, Zou X, Ferrell JE, Wang B. Ultrafast distant wound response is essential for whole-body regeneration. Cell 2023; 186:3606-3618.e16. [PMID: 37480850 PMCID: PMC10957142 DOI: 10.1016/j.cell.2023.06.019] [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: 05/26/2022] [Revised: 01/11/2023] [Accepted: 06/23/2023] [Indexed: 07/24/2023]
Abstract
Injury induces systemic responses, but their functions remain elusive. Mechanisms that can rapidly synchronize wound responses through long distances are also mostly unknown. Using planarian flatworms capable of whole-body regeneration, we report that injury induces extracellular signal-regulated kinase (Erk) activity waves to travel at a speed 10-100 times faster than those in other multicellular tissues. This ultrafast propagation requires longitudinal body-wall muscles, elongated cells forming dense parallel tracks running the length of the organism. The morphological properties of muscles allow them to act as superhighways for propagating and disseminating wound signals. Inhibiting Erk propagation prevents tissues distant to the wound from responding and blocks regeneration, which can be rescued by a second injury to distal tissues shortly after the first injury. Our findings provide a mechanism for long-range signal propagation in large, complex tissues to coordinate responses across cell types and highlight the function of feedback between spatially separated tissues during whole-body regeneration.
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Affiliation(s)
- Yuhang Fan
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Pengyang Li
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Xinzhi Zou
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - James E Ferrell
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA; Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
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12
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Cui G, Dong K, Zhou JY, Li S, Wu Y, Han Q, Yao B, Shen Q, Zhao YL, Yang Y, Cai J, Zhang S, Yang YG. Spatiotemporal transcriptomic atlas reveals the dynamic characteristics and key regulators of planarian regeneration. Nat Commun 2023; 14:3205. [PMID: 37268637 DOI: 10.1038/s41467-023-39016-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 05/25/2023] [Indexed: 06/04/2023] Open
Abstract
Whole-body regeneration of planarians is a natural wonder but how it occurs remains elusive. It requires coordinated responses from each cell in the remaining tissue with spatial awareness to regenerate new cells and missing body parts. While previous studies identified new genes essential to regeneration, a more efficient screening approach that can identify regeneration-associated genes in the spatial context is needed. Here, we present a comprehensive three-dimensional spatiotemporal transcriptomic landscape of planarian regeneration. We describe a pluripotent neoblast subtype, and show that depletion of its marker gene makes planarians more susceptible to sub-lethal radiation. Furthermore, we identified spatial gene expression modules essential for tissue development. Functional analysis of hub genes in spatial modules, such as plk1, shows their important roles in regeneration. Our three-dimensional transcriptomic atlas provides a powerful tool for deciphering regeneration and identifying homeostasis-related genes, and provides a publicly available online spatiotemporal analysis resource for planarian regeneration research.
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Affiliation(s)
- Guanshen Cui
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
| | - Kangning Dong
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jia-Yi Zhou
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China.
- China National Center for Bioinformation, Beijing, 100101, China.
| | - Shang Li
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying Wu
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
| | - Qinghua Han
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bofei Yao
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
| | - Qunlun Shen
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong-Liang Zhao
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ying Yang
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 101408, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jun Cai
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China.
- China National Center for Bioinformation, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Shihua Zhang
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China.
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223, China.
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
| | - Yun-Gui Yang
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China.
- China National Center for Bioinformation, Beijing, 100101, China.
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 101408, China.
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
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13
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Fan Y, Chai C, Li P, Zou X, Ferrell JE, Wang B. Ultrafast and long-range coordination of wound responses is essential for whole-body regeneration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.15.532844. [PMID: 36993633 PMCID: PMC10055111 DOI: 10.1101/2023.03.15.532844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Injury induces systemic, global responses whose functions remain elusive. In addition, mechanisms that rapidly synchronize wound responses through long distances across the organismal scale are mostly unknown. Using planarians, which have extreme regenerative ability, we report that injury induces Erk activity to travel in a wave-like manner at an unexpected speed (∼1 mm/h), 10-100 times faster than those measured in other multicellular tissues. This ultrafast signal propagation requires longitudinal body-wall muscles, elongated cells forming dense parallel tracks running the length of the organism. Combining experiments and computational models, we show that the morphological properties of muscles allow them to minimize the number of slow intercellular signaling steps and act as bidirectional superhighways for propagating wound signals and instructing responses in other cell types. Inhibiting Erk propagation prevents cells distant to the wound from responding and blocks regeneration, which can be rescued by a second injury to distal tissues within a narrow time window after the first injury. These results suggest that rapid responses in uninjured tissues far from wounds are essential for regeneration. Our findings provide a mechanism for long-range signal propagation in large and complex tissues to coordinate cellular responses across diverse cell types, and highlights the function of feedback between spatially separated tissues during whole-body regeneration.
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Affiliation(s)
- Yuhang Fan
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Pengyang Li
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Xinzhi Zou
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - James E. Ferrell
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA
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14
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Guo Y, Sun Y, Ma M, Huang Y, Zhang S, Tian Q. Djsnon, a downstream gene of Djfoxk1, is required for the regeneration of the planarian central nervous system. Biochem Biophys Res Commun 2023; 643:8-15. [PMID: 36584589 DOI: 10.1016/j.bbrc.2022.12.074] [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: 12/12/2022] [Accepted: 12/23/2022] [Indexed: 12/25/2022]
Abstract
Regulators of adult neurogenesis are crucial targets for neuronal repair. Freshwater planarians are ideal model systems for studying neuronal regeneration as they can regenerate their entire central nervous system (CNS) using pluripotent adult stem cells. Here, we identified Djfoxk1 in planarian Dugesia japonica to be required for planarian CNS regeneration. Knockdown of Djfoxk1 inhibits the regeneration of the cephalic ganglia, resulting in the failure of eye regeneration. By RNAi screening of Djfoxk1 downstream genes, we identified Djsnon as another regulator of planarian neuronal regeneration. Inhibition of Djsnon with RNA interference (RNAi) results in similar phenotypes caused by Djfoxk1 RNAi without affecting cell proliferation and wound healing. Our findings show that Djsnon as a downstream gene of Djfoxk1 regulates the regeneration of the planarian CNS.
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Affiliation(s)
- Yajun Guo
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Yujia Sun
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Mengwen Ma
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Yongding Huang
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Shoutao Zhang
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China; Longhu Laboratory of Advanced Immunology, Zhengzhou, Henan, China.
| | - Qingnan Tian
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China.
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15
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Wnt/β-catenin signalling is required for pole-specific chromatin remodeling during planarian regeneration. Nat Commun 2023; 14:298. [PMID: 36653403 PMCID: PMC9849279 DOI: 10.1038/s41467-023-35937-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 01/09/2023] [Indexed: 01/19/2023] Open
Abstract
For successful regeneration, the identity of the missing tissue must be specified according to the pre-existing tissue. Planarians are ideal for the study of the mechanisms underlying this process; the same field of cells can regrow a head or a tail according to the missing body part. After amputation, the differential activation of the Wnt/β-catenin signal specifies anterior versus posterior identity. Initially, both wnt1 and notum (Wnt inhibitor) are expressed in all wounds, but 48 hours later they are restricted to posterior or anterior facing wounds, respectively, by an unknown mechanism. Here we show that 12 hours after amputation, the chromatin accessibility of cells in the wound region changes according to the polarity of the pre-existing tissue in a Wnt/β-catenin-dependent manner. Genomic analyses suggest that homeobox transcription factors and chromatin-remodeling proteins are direct Wnt/β-catenin targets, which trigger the expression of posterior effectors. Finally, we identify FoxG as a wnt1 up-stream regulator, probably via binding to its first intron enhancer region.
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16
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Planarians to schistosomes: an overview of flatworm cell-types and regulators. J Helminthol 2023; 97:e7. [PMID: 36644809 DOI: 10.1017/s0022149x22000621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Schistosomiasis remains a major neglected tropical disease that afflicts over 200 million people globally. Schistosomes, the aetiological agent of schistosomiasis, are parasitic flatworms that propagate between molluscan and mammalian hosts. Inside the mammalian host, schistosomes rapidly grow over 100-fold in size and develop into a sexually mature male or female that thrives in the bloodstream for several decades. Recent work has identified schistosome stem cells as the source that drives parasite transmission, reproduction and longevity. Moreover, studies have begun to uncover molecular programmes deployed by stem cells that are essential for tissue development and maintenance, parasite survival and immune evasion. Such programmes are reminiscent of neoblast-driven development and regeneration of planarians, the free-living flatworm relative of schistosomes. Over the last few decades, research in planarians has employed modern functional genomic tools that significantly enhanced our understanding of stem cell-driven animal development and regeneration. In this review, we take a broad stroke overview of major flatworm organ systems at the cellular and molecular levels. We summarize recent advances on genetic regulators that play critical roles in differentiation and maintenance of flatworm cell types. Finally, we provide perspectives on how investigation of basic parasite biology is critical to discovering new approaches to battle schistosomiasis.
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17
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Petersen CP. Wnt signaling in whole-body regeneration. Curr Top Dev Biol 2023; 153:347-380. [PMID: 36967200 DOI: 10.1016/bs.ctdb.2023.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Regeneration abilities are widespread among animals and select species can restore any body parts removed by wounds that sever the major body axes. This capability of whole-body regeneration as exemplified in flatworm planarians, Acoels, and Cnidarians involves initial responses to injury, the assessment of wound site polarization, determination of missing tissue and programming of blastema fate, and patterned outgrowth to restore axis content and proportionality. Wnt signaling drives many shared and conserved aspects of the biology of whole-body regeneration in the planarian species Schmidtea mediterranea and Dugesia japonica, in the Acoel Hofstenia miamia, and in Cnidarians Hydra and Nematostella. These overlapping mechanisms suggest whole-body regeneration might be an ancestral property across diverse animal taxa.
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Affiliation(s)
- Christian P Petersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States; Robert Lurie Comprehensive Cancer Center, Northwestern University, Evanston, IL, United States.
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18
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Hoffman M, Wurtzel O. PLANAtools-An interactive gene expression repository for the planarian Schmidtea mediterranea. Front Cell Dev Biol 2023; 11:1149537. [PMID: 37035247 PMCID: PMC10076545 DOI: 10.3389/fcell.2023.1149537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 03/16/2023] [Indexed: 04/11/2023] Open
Affiliation(s)
- Michael Hoffman
- The George S. Wise Faculty of Life Sciences, School of Neurobiology, Biochemistry, and Biophysics, Tel Aviv University, Tel Aviv, Israel
| | - Omri Wurtzel
- The George S. Wise Faculty of Life Sciences, School of Neurobiology, Biochemistry, and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Omri Wurtzel,
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19
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Gittin DI, Petersen CP. A Wnt11 and Dishevelled signaling pathway acts prior to injury to control wound polarization for the onset of planarian regeneration. Curr Biol 2022; 32:5262-5273.e2. [PMID: 36495871 PMCID: PMC9901562 DOI: 10.1016/j.cub.2022.10.071] [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: 03/14/2022] [Revised: 09/20/2022] [Accepted: 10/27/2022] [Indexed: 12/13/2022]
Abstract
Regeneration is initiated by wounding, but it is unclear how injury-induced signals precisely convey the identity of the tissues requiring replacement. In the planarian Schmidtea mediterranea, the first event in head regeneration is the asymmetric activation of the Wnt inhibitor notum in longitudinal body-wall muscle cells, preferentially at anterior-facing versus posterior-facing wound sites. However, the mechanism driving this early symmetry-breaking event is unknown. We identify a noncanonical Wnt11 and Dishevelled pathway regulating notum polarization, which opposes injury-induced notum-activating Wnt/β-catenin signals and regulates muscle orientation. Using expression analysis and experiments to define a critical time of action, we demonstrate that Wnt11 and Dishevelled signals act prior to injury and in a growth-dependent manner to orient the polarization of notum induced by wounding. In turn, injury-induced notum dictates polarization used in the next round of regeneration. These results identify a self-reinforcing feedback system driving the polarization of blastema outgrowth and indicate that regeneration uses pre-existing tissue information to determine the outcome of wound-induced signals.
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Affiliation(s)
- David I Gittin
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Christian P Petersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA; Robert Lurie Comprehensive Cancer Center, Northwestern University, Evanston, IL 60208, USA.
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20
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Hendin N, Gordon T, Shenkar N, Wurtzel O. Molecular characterization of the immediate wound response of the solitary ascidian Polycarpa mytiligera. Dev Dyn 2022; 251:1968-1981. [PMID: 36001356 PMCID: PMC10087333 DOI: 10.1002/dvdy.526] [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: 03/13/2022] [Revised: 06/16/2022] [Accepted: 07/05/2022] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Injury response is key to successful regeneration. Yet, transcriptome analyses of injury response were performed only on a handful of regenerative organisms. Here, we studied the injury response of the solitary ascidian Polycarpa mytiligera, an emerging model system, capable of regenerating any body part. We used the siphon as a model for studying transcriptional changes following injury, and identified genes that were activated in the initial 24 hours post amputation (hpa). RESULTS Highly conserved genes, such as bone morphogenetic protein-1 (BMP1), growth hormone secretagogue receptor (GHSR) and IL-17, were upregulated by 12 hpa, yet their expression was sustained only in non-regenerating tissue fragments. We optimized fluorescent in situ hybridization, and found that the majority of BMP1+ cells were localized to the rigid tunic that covers the animal. This highlights the importance of this tissue, particularly during injury response. BMP1 was overexpressed following injuries to other body regions, suggesting that it was a part of a common injury-induced program. CONCLUSION Our study suggests that, initially, specific injury-induced genes were upregulated in P. mytiligera organs, yet, later, a unique transcriptional profile was observed only in regenerating tissues. These findings highlight the importance of studying diverse regenerating and non-regenerating organisms for complete understanding of regeneration.
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Affiliation(s)
- Noam Hendin
- The School of Neurobiology, Biochemistry & Biophysics, George S. Wise Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
| | - Tal Gordon
- The School of Neurobiology, Biochemistry & Biophysics, George S. Wise Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
| | - Noa Shenkar
- School of Zoology, George S. Wise Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
- The Steinhardt Museum of Natural History, Israel National Center for Biodiversity StudiesTel‐Aviv UniversityTel‐AvivIsrael
| | - Omri Wurtzel
- The School of Neurobiology, Biochemistry & Biophysics, George S. Wise Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
- Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
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21
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Koike A, Becker F, Sennhenn P, Kim J, Zhang J, Hannus S, Brehm K. Targeting Echinococcus multilocularis PIM kinase for improving anti-parasitic chemotherapy. PLoS Negl Trop Dis 2022; 16:e0010483. [PMID: 36190997 PMCID: PMC9560627 DOI: 10.1371/journal.pntd.0010483] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 10/13/2022] [Accepted: 09/20/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND The potentially lethal zoonosis alveolar echinococcosis (AE) is caused by the metacestode larval stage of the tapeworm Echinococcus multilocularis. Current AE treatment options are limited and rely on surgery as well as on chemotherapy involving benzimidazoles (BZ). BZ treatment, however, is mostly parasitostatic only, must be given for prolonged time periods, and is associated with adverse side effects. Novel treatment options are thus urgently needed. METHODOLOGY/PRINCIPAL FINDINGS By applying a broad range of kinase inhibitors to E. multilocularis stem cell cultures we identified the proto-oncogene PIM kinase as a promising target for anti-AE chemotherapy. The gene encoding the respective E. multilocularis ortholog, EmPim, was characterized and in situ hybridization assays indicated its expression in parasite stem cells. By yeast two-hybrid assays we demonstrate interaction of EmPim with E. multilocularis CDC25, indicating an involvement of EmPim in parasite cell cycle regulation. Small molecule compounds SGI-1776 and CX-6258, originally found to effectively inhibit human PIM kinases, exhibited detrimental effects on in vitro cultured parasite metacestode vesicles and prevented the formation of mature vesicles from parasite stem cell cultures. To improve compound specificity for EmPim, we applied a high throughput in silico modelling approach, leading to the identification of compound Z196138710. When applied to in vitro cultured metacestode vesicles and parasite cell cultures, Z196138710 proved equally detrimental as SGI-1776 and CX-6258 but displayed significantly reduced toxicity towards human HEK293T and HepG2 cells. CONCLUSIONS/SIGNIFICANCE Repurposing of kinase inhibitors initially designed to affect mammalian kinases for helminth disease treatment is often hampered by adverse side effects of respective compounds on human cells. Here we demonstrate the utility of high throughput in silico approaches to design small molecule compounds of higher specificity for parasite cells. We propose EmPim as a promising target for respective approaches towards AE treatment.
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Affiliation(s)
- Akito Koike
- University of Würzburg, Institute of Hygiene and Microbiology, Consultant Laboratory for Echinococcosis, Würzburg, Germany
| | | | | | - Jason Kim
- Immuneering Corporation, Cambridge, Massachusetts, United States of America
| | - Jenny Zhang
- Immuneering Corporation, Cambridge, Massachusetts, United States of America
| | | | - Klaus Brehm
- University of Würzburg, Institute of Hygiene and Microbiology, Consultant Laboratory for Echinococcosis, Würzburg, Germany
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22
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Lust K, Maynard A, Gomes T, Fleck JS, Camp JG, Tanaka EM, Treutlein B. Single-cell analyses of axolotl telencephalon organization, neurogenesis, and regeneration. Science 2022; 377:eabp9262. [PMID: 36048956 DOI: 10.1126/science.abp9262] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Salamanders are tetrapod models to study brain organization and regeneration; however, the identity and evolutionary conservation of brain cell types are largely unknown. We delineated the cell populations in the axolotl telencephalon during homeostasis and regeneration using single-cell genomic profiling. We identified glutamatergic neurons with similarities to amniote neurons of hippocampus, dorsal and lateral cortex, and conserved γ-aminobutyric acid-releasing (GABAergic) neuron classes. We inferred transcriptional dynamics and gene regulatory relationships of postembryonic, region-specific neurogenesis and unraveled conserved differentiation signatures. After brain injury, ependymoglia activate an injury-specific state before reestablishing lost neuron populations and axonal connections. Together, our analyses yield insights into the organization, evolution, and regeneration of a tetrapod nervous system.
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Affiliation(s)
- Katharina Lust
- Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Campus Vienna Biocenter, 1030 Vienna, Austria
| | - Ashley Maynard
- Department of Biosystems Science and Engineering, ETH Zürich, 4058 Basel, Switzerland
| | - Tomás Gomes
- Department of Biosystems Science and Engineering, ETH Zürich, 4058 Basel, Switzerland
| | - Jonas Simon Fleck
- Department of Biosystems Science and Engineering, ETH Zürich, 4058 Basel, Switzerland
| | - J Gray Camp
- Roche Institute for Translational Bioengineering (ITB), Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland.,University of Basel, 4001 Basel, Switzerland
| | - Elly M Tanaka
- Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Campus Vienna Biocenter, 1030 Vienna, Austria
| | - Barbara Treutlein
- Department of Biosystems Science and Engineering, ETH Zürich, 4058 Basel, Switzerland
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23
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Injury-induced MAPK activation triggers body axis formation in Hydra by default Wnt signaling. Proc Natl Acad Sci U S A 2022; 119:e2204122119. [PMID: 35994642 PMCID: PMC9436372 DOI: 10.1073/pnas.2204122119] [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] [Indexed: 11/18/2022] Open
Abstract
Hydra's almost unlimited regenerative potential is based on Wnt signaling, but so far it is unknown how the injury stimulus is transmitted to discrete patterning fates in head and foot regenerates. We previously identified mitogen-activated protein kinases (MAPKs) among the earliest injury response molecules in Hydra head regeneration. Here, we show that three MAPKs-p38, c-Jun N-terminal kinases (JNKs), and extracellular signal-regulated kinases (ERKs)-are essential to initiate regeneration in Hydra, independent of the wound position. Their activation occurs in response to any injury and requires calcium and reactive oxygen species (ROS) signaling. Phosphorylated MAPKs hereby exhibit cross talk with mutual antagonism between the ERK pathway and stress-induced MAPKs, orchestrating a balance between cell survival and apoptosis. Importantly, Wnt3 and Wnt9/10c, which are induced by MAPK signaling, can partially rescue regeneration in tissues treated with MAPK inhibitors. Also, foot regenerates can be reverted to form head tissue by a pharmacological increase of β-catenin signaling or the application of recombinant Wnts. We propose a model in which a β-catenin-based stable gradient of head-forming capacity along the primary body axis, by differentially integrating an indiscriminate injury response, determines the fate of the regenerating tissue. Hereby, Wnt signaling acquires sustained activation in the head regenerate, while it is transient in the presumptive foot tissue. Given the high level of evolutionary conservation of MAPKs and Wnts, we assume that this mechanism is deeply embedded in our genome.
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24
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Sood P, Lin A, Yan C, McGillivary R, Diaz U, Makushok T, Nadkarni A, Tang SKY, Marshall WF. Modular, cascade-like transcriptional program of regeneration in Stentor. eLife 2022; 11:80778. [PMID: 35924891 PMCID: PMC9371601 DOI: 10.7554/elife.80778] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 08/04/2022] [Indexed: 11/15/2022] Open
Abstract
The giant ciliate Stentor coeruleus is a classical model system for studying regeneration and morphogenesis in a single cell. The anterior of the cell is marked by an array of cilia, known as the oral apparatus, which can be induced to shed and regenerate in a series of reproducible morphological steps, previously shown to require transcription. If a cell is cut in half, each half regenerates an intact cell. We used RNA sequencing (RNAseq) to assay the dynamic changes in Stentor’s transcriptome during regeneration, after both oral apparatus shedding and bisection, allowing us to identify distinct temporal waves of gene expression including kinases, RNA -binding proteins, centriole biogenesis factors, and orthologs of human ciliopathy genes. By comparing transcriptional profiles of different regeneration events, we identified distinct modules of gene expression corresponding to oral apparatus regeneration, posterior holdfast regeneration, and recovery after wounding. By measuring gene expression after blocking translation, we show that the sequential waves of gene expression involve a cascade mechanism in which later waves of expression are triggered by translation products of early-expressed genes. Among the early-expressed genes, we identified an E2F transcription factor and the RNA-binding protein Pumilio as potential regulators of regeneration based on the expression pattern of their predicted target genes. RNAi-mediated knockdown experiments indicate that Pumilio is required for regenerating oral structures of the correct size. E2F is involved in the completion of regeneration but is dispensable for earlier steps. This work allows us to classify regeneration genes into groups based on their potential role for regeneration in distinct cell regeneration paradigms, and provides insight into how a single cell can coordinate complex morphogenetic pathways to regenerate missing structures.
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Affiliation(s)
- Pranidhi Sood
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Athena Lin
- Department of Biochemistry and BioPhysics, University of California, San Francisco, San Francisco, United States
| | - Connie Yan
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Rebecca McGillivary
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Ulises Diaz
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Tatyana Makushok
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Ambika Nadkarni
- Department of Mechanical Engineering, Stanford University, palo alto, United States
| | - Sindy K Y Tang
- Department of Mechanical Engineering, Stanford University, Palo Alto, United States
| | - Wallace F Marshall
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
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25
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Djptpn11 is indispensable for planarian regeneration by affecting early wound response genes expression and the Wnt pathway. Biochimie 2022; 201:184-195. [PMID: 35868605 DOI: 10.1016/j.biochi.2022.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 12/22/2022]
Abstract
Planarian is an ideal model system of studying regeneration. Stem cell system and positional control genes (PCGs) are two important factors for perfect regeneration of planarians and they combine to promote their regeneration. Even so, how wounds regulate proliferation and neoblast fate is still important areas to address. Ptpn11 (Protein tyrosine phosphatase non-receptor type 11), one of PTP (Protein tyrosine phosphatase) family members, plays an important role in cellular processes including cell survival, proliferation, differentiation and apoptosis. Nevertheless, the role of ptpn11 in the planarian regeneration has not been fully studied. In this study, we identify the Djptpn11 gene to observe its function in planarian regeneration. The results reveal that the regeneration is severely inhibited and cause the disorder homeostasis in planarians. Furthermore, the stem cells proliferation and differentiation decreases while the apoptosis increases following Djptpn11 RNAi. At the same time, Djptpn11 affects the expression levels of early wound response genes (Djegr2, Dj1-jun, Djrunt1, Djwnt1 and Djnotum). Djwnt1 and Djnotum are two key Wnt signaling pathway genes and Djptpn11 affects the expression levels of Djwnt1 and Djnotum in the early and late stages of planarian regeneration. In general, Djptpn11 is indispensable for the homeostasis and regeneration of planarian by affecting the stem cells, early wound response genes and the Wnt pathway.
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26
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Scimone ML, Cloutier JK, Maybrun CL, Reddien PW. The planarian wound epidermis gene equinox is required for blastema formation in regeneration. Nat Commun 2022; 13:2726. [PMID: 35585061 PMCID: PMC9117669 DOI: 10.1038/s41467-022-30412-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 04/09/2022] [Indexed: 11/25/2022] Open
Abstract
Regeneration often involves the formation of a blastema, an outgrowth or regenerative bud formed at the plane of injury where missing tissues are produced. The mechanisms that trigger blastema formation are therefore fundamental for regeneration. Here, we identify a gene, which we named equinox, that is expressed within hours of injury in the planarian wound epidermis. equinox encodes a predicted secreted protein that is conserved in many animal phyla. Following equinox inhibition, amputated planarians fail to maintain wound-induced gene expression and to subsequently undergo blastema outgrowth. Associated with these defects is an inability to reestablish lost positional information needed for missing tissue specification. Our findings link the planarian wound epidermis, through equinox, to regeneration of positional information and blastema formation, indicating a broad regulatory role of the wound epidermis in diverse regenerative contexts.
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Affiliation(s)
- M Lucila Scimone
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
| | - Jennifer K Cloutier
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Harvard/MIT MD-PhD, Harvard Medical School, Boston, MA, 02115, USA
| | - Chloe L Maybrun
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Peter W Reddien
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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27
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Reddien PW. Positional Information and Stem Cells Combine to Result in Planarian Regeneration. Cold Spring Harb Perspect Biol 2022; 14:a040717. [PMID: 34518341 PMCID: PMC9121904 DOI: 10.1101/cshperspect.a040717] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The capacity for regeneration is broad in the animal kingdom. Planarians are flatworms that can regenerate any missing body part and their regenerative powers have combined with ease of experimentation to make them a classic regeneration model for more than a century. Pluripotent stem cells called neoblasts generate missing planarian tissues. Fate specification happens in the neoblasts, and this can occur in response to regeneration instructions in the form of positional information. Fate specification can lead to differentiating cells in single steps rather than requiring a long lineage hierarchy. Planarians display constitutive expression of positional information from muscle cells, which is required for patterned maintenance of tissues in tissue turnover. Amputation leads to the rapid resetting of positional information in a process triggered by wound signaling and the resetting of positional information is required for regeneration. These findings suggest a model for planarian regeneration in which adult positional information resets after injury to regulate stem cells to bring about the replacement of missing parts.
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Affiliation(s)
- Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA
- Department of Biology, MIT, Cambridge, Massachusetts 02139, USA
- Department of Biology, MIT, Cambridge, Massachusetts 02139, USA
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28
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Avalos PN, Forsthoefel DJ. An Emerging Frontier in Intercellular Communication: Extracellular Vesicles in Regeneration. Front Cell Dev Biol 2022; 10:849905. [PMID: 35646926 PMCID: PMC9130466 DOI: 10.3389/fcell.2022.849905] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/28/2022] [Indexed: 12/12/2022] Open
Abstract
Regeneration requires cellular proliferation, differentiation, and other processes that are regulated by secreted cues originating from cells in the local environment. Recent studies suggest that signaling by extracellular vesicles (EVs), another mode of paracrine communication, may also play a significant role in coordinating cellular behaviors during regeneration. EVs are nanoparticles composed of a lipid bilayer enclosing proteins, nucleic acids, lipids, and other metabolites, and are secreted by most cell types. Upon EV uptake by target cells, EV cargo can influence diverse cellular behaviors during regeneration, including cell survival, immune responses, extracellular matrix remodeling, proliferation, migration, and differentiation. In this review, we briefly introduce the history of EV research and EV biogenesis. Then, we review current understanding of how EVs regulate cellular behaviors during regeneration derived from numerous studies of stem cell-derived EVs in mammalian injury models. Finally, we discuss the potential of other established and emerging research organisms to expand our mechanistic knowledge of basic EV biology, how injury modulates EV biogenesis, cellular sources of EVs in vivo, and the roles of EVs in organisms with greater regenerative capacity.
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Affiliation(s)
- Priscilla N. Avalos
- Department of Cell Biology, College of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Genes and Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - David J. Forsthoefel
- Department of Cell Biology, College of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Genes and Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
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29
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Single-cell transcriptome analysis reveals three sequential phases of gene expression during zebrafish sensory hair cell regeneration. Dev Cell 2022; 57:799-819.e6. [PMID: 35316618 PMCID: PMC9188816 DOI: 10.1016/j.devcel.2022.03.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 11/19/2021] [Accepted: 02/28/2022] [Indexed: 12/20/2022]
Abstract
Loss of sensory hair cells (HCs) in the mammalian inner ear leads to permanent hearing and vestibular defects, whereas loss of HCs in zebrafish results in their regeneration. We used single-cell RNA sequencing (scRNA-seq) to characterize the transcriptional dynamics of HC regeneration in zebrafish at unprecedented spatiotemporal resolution. We uncovered three sequentially activated modules: first, an injury/inflammatory response and downregulation of progenitor cell maintenance genes within minutes after HC loss; second, the transient activation of regeneration-specific genes; and third, a robust re-activation of developmental gene programs, including HC specification, cell-cycle activation, ribosome biogenesis, and a metabolic switch to oxidative phosphorylation. The results are relevant not only for our understanding of HC regeneration and how we might be able to trigger it in mammals but also for regenerative processes in general. The data are searchable and publicly accessible via a web-based interface.
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30
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Coronel-Córdoba P, Molina MD, Cardona G, Fraguas S, Pascual-Carreras E, Saló E, Cebrià F, Adell T. FoxK1 is Required for Ectodermal Cell Differentiation During Planarian Regeneration. Front Cell Dev Biol 2022; 10:808045. [PMID: 35273960 PMCID: PMC8901602 DOI: 10.3389/fcell.2022.808045] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/25/2022] [Indexed: 11/24/2022] Open
Abstract
Forkhead box (Fox) genes belong to the “winged helix” transcription factor superfamily. The function of some Fox genes is well known, such as the role of foxO in controlling metabolism and longevity and foxA in controlling differentiation of endodermal tissues. However, the role of some Fox factors is not yet well characterized. Such is the case of FoxK genes, which are mainly studied in mammals and have been implicated in diverse processes including cell proliferation, tissue differentiation and carcinogenesis. Planarians are free-living flatworms, whose importance in biomedical research lies in their regeneration capacity. Planarians possess a wide population of pluripotent adult stem cells, called neoblasts, which allow them to regenerate any body part after injury. In a recent study, we identified three foxK paralogs in the genome of Schmidtea mediterranea. In this study, we demonstrate that foxK1 inhibition prevents regeneration of the ectodermal tissues, including the nervous system and the epidermis. These results correlate with foxK1 expression in neoblasts and in neural progenitors. Although the triggering of wound genes expression, polarity reestablishment and proliferation was not affected after foxK1 silencing, the apoptotic response was decreased. Altogether, these results suggest that foxK1 would be required for differentiation and maintenance of ectodermal tissues.
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Affiliation(s)
- Pablo Coronel-Córdoba
- 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
| | - 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
| | - Gemma Cardona
- 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
| | - Eudald Pascual-Carreras
- 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
| | - Emili Saló
- 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
| | - Teresa Adell
- 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
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31
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Lee H, Hikasa K, Umesono Y, Hayashi T, Agata K, Shibata N. Loss of plac8 expression rapidly leads pluripotent stem cells to enter active state during planarian regeneration. Development 2022; 149:274215. [DOI: 10.1242/dev.199449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 12/20/2021] [Indexed: 01/18/2023]
Abstract
ABSTRACT
The regenerative ability of planarians relies on their adult pluripotent stem cell population. Although all stem cells express a piwi homolog, recently it has become possible to classify the piwi+ stem cell population into specialized subpopulations according to the expression of genes related to differentiation. However, piwi+ stem cells behave practically as a homogeneous population after amputation, during which stem cells show accelerated proliferation, named ‘induced hyperproliferation’. Here, we show that plac8-A was expressed in almost all of the stem cells, and that a decrease of the plac8-A expression level led to induced hyperproliferation uniformly in a broad stem cell subpopulation after amputation. This reduction of plac8-A expression was caused by activated JNK signaling after amputation. Pharmacological inhibition of JNK signaling caused failure to induce hyperproliferation and resulted in regenerative defects. Such defects were abrogated by simultaneous knockdown of plac8-A expression. Thus, JNK-dependent suppression of plac8-A expression is indispensable for stem cell dynamics involved in regeneration. These findings suggest that plac8-A acts as a molecular switch of piwi+ stem cells for entry into the regenerative state after amputation.
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Affiliation(s)
- Hayoung Lee
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kanon Hikasa
- Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College 624-1, Numa, Tsuyama-City, Okayama 708-8509, Japan
| | - Yoshihiko Umesono
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Tetsutaro Hayashi
- Laboratory for Phyloinformatics, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
- Laboratory for Bioinformatics Research, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
- Laboratory of Regeneration Biology, National Institute for Basic Biology, Nishigoaka 38, Myodaiji, Okazaki, 444-8585 Aichi, Japan
| | - Norito Shibata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
- Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College 624-1, Numa, Tsuyama-City, Okayama 708-8509, Japan
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32
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Effect of weak alternating magnetic fields on planarian regeneration. Biochem Biophys Res Commun 2021; 592:7-12. [PMID: 35007847 DOI: 10.1016/j.bbrc.2021.12.096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 12/25/2021] [Indexed: 11/23/2022]
Abstract
We investigated the effect of weak combined magnetic field (CMF) on stem cell proliferation and regeneration of the planarian Schmidtea mediterranea. CMF parameters were set in accordance with Valery Lednev's theory of magnetic parametric resonance. It was shown that CMF with an amplitude of 74 μT and a frequency of 30 Hz accelerated the growth of the planarian head blastema by 25%. Alterations of the frequency in range from 27 to 33 Hz led to a complete disappearance of the effect. A further decrease in the CMF frequency inhibited regeneration. The maximum inhibition (24%) was observed at a frequency of 16 Hz. A further decrease in the CMF frequency (down to 13 Hz) led to disappearance of the described effect. Regeneration rate changes under the CMF are influenced by alterations in stem cell mitotic activity, which in turn depends on the wound-induced gene expression level. Thus, the CMF, preset in accordance to the Lednev's theory, can specifically influence the expression of regeneration-related genes and regeneration itself, what can find biomedical applications.
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33
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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.
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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.
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34
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Transcription Factors Active in the Anterior Blastema of Schmidtea mediterranea. Biomolecules 2021; 11:biom11121782. [PMID: 34944426 PMCID: PMC8698962 DOI: 10.3390/biom11121782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/28/2022] Open
Abstract
Regeneration, the restoration of body parts after injury, is quite widespread in the animal kingdom. Species from virtually all Phyla possess regenerative abilities. Human beings, however, are poor regenerators. Yet, the progress of knowledge and technology in the fields of bioengineering, stem cells, and regenerative biology have fostered major advancements in regenerative medical treatments, which aim to regenerate tissues and organs and restore function. Human induced pluripotent stem cells can differentiate into any cell type of the body; however, the structural and cellular complexity of the human tissues, together with the inability of our adult body to control pluripotency, require a better mechanistic understanding. Planarians, with their capacity to regenerate lost body parts thanks to the presence of adult pluripotent stem cells could help providing such an understanding. In this paper, we used a top-down approach to shortlist blastema transcription factors (TFs) active during anterior regeneration. We found 44 TFs—31 of which are novel in planarian—that are expressed in the regenerating blastema. We analyzed the function of half of them and found that they play a role in the regeneration of anterior structures, like the anterior organizer, the positional instruction muscle cells, the brain, the photoreceptor, the intestine. Our findings revealed a glimpse of the complexity of the transcriptional network governing anterior regeneration in planarians, confirming that this animal model is the perfect playground to study in vivo how pluripotency copes with adulthood.
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35
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Almazan EMP, Ryan JF, Rouhana L. Regeneration of Planarian Auricles and Reestablishment of Chemotactic Ability. Front Cell Dev Biol 2021; 9:777951. [PMID: 34901022 PMCID: PMC8662385 DOI: 10.3389/fcell.2021.777951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Detection of chemical stimuli is crucial for living systems and also contributes to quality of life in humans. Since loss of olfaction becomes more prevalent with aging, longer life expectancies have fueled interest in understanding the molecular mechanisms behind the development and maintenance of chemical sensing. Planarian flatworms possess an unsurpassed ability for stem cell-driven regeneration that allows them to restore any damaged or removed part of their bodies. This includes anteriorly-positioned lateral flaps known as auricles, which have long been thought to play a central role in chemotaxis. The contribution of auricles to the detection of positive chemical stimuli was tested in this study using Girardia dorotocephala, a North American planarian species known for its morphologically prominent auricles. Behavioral experiments staged under laboratory conditions revealed that removal of auricles by amputation leads to a significant decrease in the ability of planarians to find food. However, full chemotactic capacity is observed as early as 2 days post-amputation, which is days prior from restoration of auricle morphology, but correlative with accumulation of ciliated cells in the position of auricle regeneration. Planarians subjected to x-ray irradiation prior to auricle amputation were unable to restore auricle morphology, but were still able to restore chemotactic capacity. These results indicate that although regeneration of auricle morphology requires stem cells, some restoration of chemotactic ability can still be achieved in the absence of normal auricle morphology, corroborating with the initial observation that chemotactic success is reestablished 2-days post-amputation in our assays. Transcriptome profiles of excised auricles were obtained to facilitate molecular characterization of these structures, as well as the identification of genes that contribute to chemotaxis and auricle development. A significant overlap was found between genes with preferential expression in auricles of G. dorotocephala and genes with reduced expression upon SoxB1 knockdown in Schmidtea mediterranea, suggesting that SoxB1 has a conserved role in regulating auricle development and function. Models that distinguish between possible contributions to chemotactic behavior obtained from cellular composition, as compared to anatomical morphology of the auricles, are discussed.
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Affiliation(s)
| | - Joseph F. Ryan
- Whitney Laboratory of Marine Biosciences, University of Florida, St. Augustine, FL, United States
- Department of Biology, University of Florida, Gainesville, FL, United States
| | - Labib Rouhana
- Department of Biological Sciences, Wright State University, Dayton, OH, United States
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36
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Le D, Sabry Z, Chandra A, Kristan WB, Collins EMS, Kristan WB. Planarian fragments behave as whole animals. Curr Biol 2021; 31:5111-5117.e4. [PMID: 34624209 DOI: 10.1016/j.cub.2021.09.056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/08/2021] [Accepted: 09/22/2021] [Indexed: 12/11/2022]
Abstract
Behavioral responses of freshwater planarians have been studied for over a century.1 In recent decades, behavior has been used as a readout to study planarian development and regeneration,2-6 wound healing,7,8 molecular evolution,4,9,10 neurotoxicology,11-13 and learning and memory.14-17The planarian nervous system is among the simplest of the bilaterally symmetric animals,18 with an anterior brain attached to two ventral nerve cords interconnected by multiple commissures. We found that, in response to mechanical and near-UV stimulation, head stimulation produces turning, tail stimulation produces contraction, and trunk stimulation produces midbody elongation in the planarian Dugesia japonica. When cut into two or three pieces, the anterior end of each headless piece switched its behavior to turning instead of elongation; i.e., it responded as though it were the head. In addition, posterior ends of the head and midbody pieces sometimes produced contraction instead of elongation. Thus, each severed piece acts like an intact animal, with each midbody region having nearly complete behavioral capabilities. These observations show that each midbody region reads the global state of the organism and adapts its response to incoming signals from the remaining tissue. Selective lateral incisions showed that the changes in behavior are not due to nonselective pain responses and that the ventral nerve cords and cross-connectives are responsible for coordinating local behaviors. Our findings highlight a fast functional reorganization of the planarian nervous system that complements the slower repairs provided by regeneration. This reorganization provides needed behavioral responses for survival as regeneration proceeds.
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Affiliation(s)
- Dylan Le
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Ziad Sabry
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
| | - Aarav Chandra
- The Bishop's School, 7607 La Jolla Boulevard, La Jolla, CA 92037, USA
| | - William B Kristan
- Department of Biological Sciences, California State University San Marcos, 333 South Twin Oaks Valley Road, San Marcos, CA 92096, USA
| | - Eva-Maria S Collins
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA; Department of Physics and Astronomy, 500 College Avenue, Swarthmore College, Swarthmore, PA 19081, USA; Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, Philadelphia, PA, USA.
| | - William B Kristan
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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Tian Q, Sun Y, Gao T, Li J, Fang H, Zhang S. Djnedd4L Is Required for Head Regeneration by Regulating Stem Cell Maintenance in Planarians. Int J Mol Sci 2021; 22:ijms222111707. [PMID: 34769140 PMCID: PMC8583885 DOI: 10.3390/ijms222111707] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/22/2021] [Accepted: 10/24/2021] [Indexed: 12/02/2022] Open
Abstract
SUMOylation and ubiquitylation are homologous processes catalyzed by homologous enzymes, and they are involved in nearly all aspects of eukaryotic biology. Planarians, which have the remarkable ability to regenerate their central nervous system (CNS), provide an excellent opportunity to investigate the molecular processes of CNS regeneration in vivo. In this study, we analyzed gene expression profiles during head regeneration with an RNA-seq-based screening approach and found that Djnedd4L and Djubc9 were required for head regeneration in planarians. RNA interference targeting of Djubc9 caused the phospho-H3 mitotic cells to decrease in quantity, or even become absent as a part of the Djubc9 RNAi phenotype, which also showed the collapse of the stem cell lineage along with the reduced expression of epidermal differentiation markers. Furthermore, we found that Djnedd4L RNAi induced increased cell division and promoted the premature differentiation during regeneration. Taken together, our findings show that Djubc9 and Djnedd4L are required for stem cell maintenance in the planarian Dugesia japonica, which helps to elucidate the role of SUMOylation and ubiquitylation in regulating the regeneration process.
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Affiliation(s)
- Qingnan Tian
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.T.); (Y.S.); (T.G.); (J.L.)
| | - Yujia Sun
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.T.); (Y.S.); (T.G.); (J.L.)
| | - Tingting Gao
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.T.); (Y.S.); (T.G.); (J.L.)
| | - Jiaxin Li
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.T.); (Y.S.); (T.G.); (J.L.)
| | - Huimin Fang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.T.); (Y.S.); (T.G.); (J.L.)
- Correspondence: (H.F.); (S.Z.)
| | - Shoutao Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China; (Q.T.); (Y.S.); (T.G.); (J.L.)
- Henan Key Laboratory of Bioactive Macromolecules, Zhengzhou 450001, China
- Correspondence: (H.F.); (S.Z.)
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38
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Analysis of the early response to spinal cord injury identified a key role for mTORC1 signaling in the activation of neural stem progenitor cells. NPJ Regen Med 2021; 6:68. [PMID: 34686684 PMCID: PMC8536777 DOI: 10.1038/s41536-021-00179-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 09/30/2021] [Indexed: 02/07/2023] Open
Abstract
Xenopus laevis are able to regenerate the spinal cord during larvae stages through the activation of neural stem progenitor cells (NSPCs). Here we use high-resolution expression profiling to characterize the early transcriptome changes induced after spinal cord injury, aiming to identify the signals that trigger NSPC proliferation. The analysis delineates a pathway that starts with a rapid and transitory activation of immediate early genes, followed by migration processes and immune response genes, the pervasive increase of NSPC-specific ribosome biogenesis factors, and genes involved in stem cell proliferation. Western blot and immunofluorescence analysis showed that mTORC1 is rapidly and transiently activated after SCI, and its pharmacological inhibition impairs spinal cord regeneration and proliferation of NSPC through the downregulation of genes involved in the G1/S transition of cell cycle, with a strong effect on PCNA. We propose that the mTOR signaling pathway is a key player in the activation of NPSCs during the early steps of spinal cord regeneration.
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Molina MD, Cebrià F. Decoding Stem Cells: An Overview on Planarian Stem Cell Heterogeneity and Lineage Progression. Biomolecules 2021; 11:1532. [PMID: 34680165 PMCID: PMC8533874 DOI: 10.3390/biom11101532] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 01/26/2023] Open
Abstract
Planarians are flatworms capable of whole-body regeneration, able to regrow any missing body part after injury or amputation. The extraordinary regenerative capacity of planarians is based upon the presence in the adult of a large population of somatic pluripotent stem cells. These cells, called neoblasts, offer a unique system to study the process of stem cell specification and differentiation in vivo. In recent years, FACS-based isolation of neoblasts, RNAi functional analyses as well as high-throughput approaches such as single-cell sequencing have allowed a rapid progress in our understanding of many different aspects of neoblast biology. Here, we summarize our current knowledge on the molecular signatures that define planarian neoblasts heterogeneity, which includes a percentage of truly pluripotent stem cells, and guide the commitment of pluripotent neoblasts into lineage-specific progenitor cells, as well as their differentiation into specific planarian cell types.
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Affiliation(s)
- M. Dolores Molina
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), 08028 Barcelona, Spain
| | - Francesc Cebrià
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), 08028 Barcelona, Spain
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40
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Benham-Pyle BW, Brewster CE, Kent AM, Mann FG, Chen S, Scott AR, Box AC, Sánchez Alvarado A. Identification of rare, transient post-mitotic cell states that are induced by injury and required for whole-body regeneration in Schmidtea mediterranea. Nat Cell Biol 2021; 23:939-952. [PMID: 34475533 PMCID: PMC8855990 DOI: 10.1038/s41556-021-00734-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/14/2021] [Indexed: 01/02/2023]
Abstract
Regeneration requires the coordination of stem cells, their progeny and distant differentiated tissues. Here, we present a comprehensive atlas of whole-body regeneration in Schmidtea mediterranea and identify wound-induced cell states. An analysis of 299,998 single-cell transcriptomes captured from regeneration-competent and regeneration-incompetent fragments identified transient regeneration-activated cell states (TRACS) in the muscle, epidermis and intestine. TRACS were independent of stem cell division with distinct spatiotemporal distributions, and RNAi depletion of TRACS-enriched genes produced regeneration defects. Muscle expression of notum, follistatin, evi/wls, glypican-1 and junctophilin-1 was required for tissue polarity. Epidermal expression of agat-1/2/3, cyp3142a1, zfhx3 and atp1a1 was important for stem cell proliferation. Finally, expression of spectrinβ and atp12a in intestinal basal cells, and lrrk2, cathepsinB, myosin1e, polybromo-1 and talin-1 in intestinal enterocytes regulated stem cell proliferation and tissue remodelling, respectively. Our results identify cell types and molecules that are important for regeneration, indicating that regenerative ability can emerge from coordinated transcriptional plasticity across all three germ layers.
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Affiliation(s)
- Blair W Benham-Pyle
- Stowers Institute for Medical Research, Kansas City, MO, USA.
- Howard Hughes Institute for Medical Research, Kansas City, MO, USA.
| | | | - Aubrey M Kent
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Frederick G Mann
- Stowers Institute for Medical Research, Kansas City, MO, USA
- Howard Hughes Institute for Medical Research, Kansas City, MO, USA
| | - Shiyuan Chen
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Allison R Scott
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Andrew C Box
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, Kansas City, MO, USA.
- Howard Hughes Institute for Medical Research, Kansas City, MO, USA.
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41
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Zheng H, Liu H, Xu Q, Wang W, Li L, Ye G, Wen X, Chen F, Yu Y. PI3K Plays an Essential Role in Planarian Regeneration and Tissue Maintenance. Front Cell Dev Biol 2021; 9:649656. [PMID: 34422792 PMCID: PMC8377419 DOI: 10.3389/fcell.2021.649656] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 07/19/2021] [Indexed: 11/13/2022] Open
Abstract
Phosphatidylinositol 3-kinase (PI3K) signaling plays a central role in various biological processes, and its abnormality leads to a broad spectrum of human diseases, such as cancer, fibrosis, and immunological disorders. However, the mechanisms by which PI3K signaling regulates the behavior of stem cells during regeneration are poorly understood. Planarian flatworms possess abundant adult stem cells (called neoblasts) allowing them to develop remarkable regenerative capabilities, thus the animals represent an ideal model for studying stem cells and regenerative medicine in vivo. In this study, the spatiotemporal expression pattern of Djpi3k, a PI3K ortholog in the planarian Dugesia japonica, was investigated and suggests its potential role in wound response and tissue regeneration. A loss-of-function study was conducted using small molecules and RNA interference technique, providing evidence that PI3K signaling is required for blastema regrowth and cilia maintenance during planarian regeneration and homeostasis. Interestingly, the mitotic and apoptotic responses to amputation are substantially abated in PI3K inhibitor-treated regenerating animals, while knockdown of Djpi3k alleviates the mitotic response and postpones the peak of apoptotic cell death, which may contribute to the varying degrees of regenerative defects induced by the pharmacological and genetic approaches. These observations reveal novel roles for PI3K signaling in the regulation of the cellular responses to amputation during planarian regeneration and provide insights for investigating the disease-related genes in the regeneration-competent organism in vivo.
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Affiliation(s)
- Hanxue Zheng
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Hongbo Liu
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Qian Xu
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Wenjun Wang
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Linfeng Li
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Gang Ye
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Xiaomin Wen
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Fulin Chen
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China.,Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, China
| | - Yuan Yu
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China.,Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, China
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42
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Srivastava M. Beyond Casual Resemblances: Rigorous Frameworks for Comparing Regeneration Across Species. Annu Rev Cell Dev Biol 2021; 37:415-440. [PMID: 34288710 DOI: 10.1146/annurev-cellbio-120319-114716] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The majority of animal phyla have species that can regenerate. Comparing regeneration across animals can reconstruct the molecular and cellular evolutionary history of this process. Recent studies have revealed some similarity in regeneration mechanisms, but rigorous comparative methods are needed to assess whether these resemblances are ancestral pathways (homology) or are the result of convergent evolution (homoplasy). This review aims to provide a framework for comparing regeneration across animals, focusing on gene regulatory networks (GRNs), which are substrates for assessing process homology. The homology of the wound-induced activation of Wnt signaling and of adult stem cells are discussed as examples of ongoing studies of regeneration that enable comparisons in a GRN framework. Expanding the study of regeneration GRNs in currently studied species and broadening taxonomic sampling for these approaches will identify processes that are unifying principles of regeneration biology across animals. These insights are important both for evolutionary studies of regeneration and for human regenerative medicine. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Mansi Srivastava
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138, USA;
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43
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Scheel A, Stevens A, Tenbrock C. Signaling gradients in surface dynamics as basis for planarian regeneration. J Math Biol 2021; 83:6. [PMID: 34173885 DOI: 10.1007/s00285-021-01627-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 06/01/2021] [Accepted: 06/13/2021] [Indexed: 10/21/2022]
Abstract
Based on experimental data, we introduce and analyze a system of reaction-diffusion equations for the regeneration of planarian flatworms. We model dynamics of head and tail cells expressing positional control genes that translate into localized signals which in turn guide stem cell differentiation. Tissue orientation and positional information are encoded in a long range wnt-related signaling gradient. Our system correctly reproduces typical cut and graft experiments, and improves on previous models by preserving polarity in regeneration over orders of magnitude in body size during growth phases. Key to polarity preservation in our model flatworm is the sensitivity of cell differentiation to gradients of wnt-related signals relative to the tissue surface. This process is particularly relevant in small tissue layers close to cuts during their healing, and modeled in a robust fashion through dynamic boundary conditions.
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Affiliation(s)
- Arnd Scheel
- School of Mathematics, University of Minnesota, 206 Church St. S.E., Minneapolis, MN, 55455, USA.
| | - Angela Stevens
- Applied Mathematics, University of Münster (WWU), Einsteinstr. 62, D-48149, Münster, Germany
| | - Christoph Tenbrock
- Applied Mathematics, University of Münster (WWU), Einsteinstr. 62, D-48149, Münster, Germany
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44
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Bohr TE, Shiroor DA, Adler CE. Planarian stem cells sense the identity of the missing pharynx to launch its targeted regeneration. eLife 2021; 10:e68830. [PMID: 34156924 PMCID: PMC8219383 DOI: 10.7554/elife.68830] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/22/2021] [Indexed: 12/25/2022] Open
Abstract
In order to regenerate tissues successfully, stem cells must detect injuries and restore missing cell types through largely unknown mechanisms. Planarian flatworms have an extensive stem cell population responsible for regenerating any organ after amputation. Here, we compare planarian stem cell responses to different injuries by either amputation of a single organ, the pharynx, or removal of tissues from other organs by decapitation. We find that planarian stem cells adopt distinct behaviors depending on what tissue is missing to target progenitor and tissue production towards missing tissues. Loss of non-pharyngeal tissues only increases non-pharyngeal progenitors, while pharynx removal selectively triggers division and expansion of pharynx progenitors. By pharmacologically inhibiting either mitosis or activation of the MAP kinase ERK, we identify a narrow window of time during which stem cell division and ERK signaling produces pharynx progenitors necessary for regeneration. These results indicate that planarian stem cells can tailor their output to match the regenerative needs of the animal.
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Affiliation(s)
- Tisha E Bohr
- Department of Molecular Medicine, Cornell University College of Veterinary MedicineIthacaUnited States
| | - Divya A Shiroor
- Department of Molecular Medicine, Cornell University College of Veterinary MedicineIthacaUnited States
| | - Carolyn E Adler
- Department of Molecular Medicine, Cornell University College of Veterinary MedicineIthacaUnited States
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45
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Genome of the fatal tapeworm Sparganum proliferum uncovers mechanisms for cryptic life cycle and aberrant larval proliferation. Commun Biol 2021; 4:649. [PMID: 34059788 PMCID: PMC8166898 DOI: 10.1038/s42003-021-02160-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 04/29/2021] [Indexed: 12/13/2022] Open
Abstract
The cryptic parasite Sparganum proliferum proliferates in humans and invades tissues and organs. Only scattered cases have been reported, but S. proliferum infection is always fatal. However, S. proliferum’s phylogeny and life cycle remain enigmatic. To investigate the phylogenetic relationships between S. proliferum and other cestode species, and to examine the mechanisms underlying pathogenicity, we sequenced the entire genomes of S. proliferum and a closely related non–life-threatening tapeworm Spirometra erinaceieuropaei. Additionally, we performed larvae transcriptome analyses of S. proliferum plerocercoid to identify genes involved in asexual reproduction in the host. The genome sequences confirmed that the S. proliferum has experienced a clearly distinct evolutionary history from S. erinaceieuropaei. Moreover, we found that nonordinal extracellular matrix coordination allows asexual reproduction in the host, and loss of sexual maturity in S. proliferum are responsible for its fatal pathogenicity to humans. Our high-quality reference genome sequences should be valuable for future studies of pseudophyllidean tapeworm biology and parasitism. Kikuchi et al. sequence the genome of the fatal tapeworm Sparganum proliferum and a closely related non–life-threatening tapeworm Spirometra erinaceieuropaei, and describe its genomic features suggesting the natural history and molecular mechanisms underlying pathogenicity. Their findings indicate that nonordinal extracellular matrix coordination is important for its asexual reproduction, and suggest that loss of sexual maturity contributes to the fatal pathogenicity of S. proliferum to humans.
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46
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Mion S, Carriot N, Lopez J, Plener L, Ortalo-Magné A, Chabrière E, Culioli G, Daudé D. Disrupting quorum sensing alters social interactions in Chromobacterium violaceum. NPJ Biofilms Microbiomes 2021; 7:40. [PMID: 33888726 PMCID: PMC8062528 DOI: 10.1038/s41522-021-00211-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 03/25/2021] [Indexed: 12/18/2022] Open
Abstract
Quorum sensing (QS) is a communication system used by bacteria to coordinate a wide panel of biological functions in a cell density-dependent manner. The Gram-negative Chromobacterium violaceum has previously been shown to use an acyl-homoserine lactone (AHL)-based QS to regulate various behaviors, including the production of proteases, hydrogen cyanide, or antimicrobial compounds such as violacein. By using combined metabolomic and proteomic approaches, we demonstrated that QS modulates the production of antimicrobial and toxic compounds in C. violaceum ATCC 12472. We provided the first evidence of anisomycin antibiotic production by this strain as well as evidence of its regulation by QS and identified new AHLs produced by C. violaceum ATCC 12472. Furthermore, we demonstrated that targeting AHLs with lactonase leads to major QS disruption yielding significant molecular and phenotypic changes. These modifications resulted in drastic changes in social interactions between C. violaceum and a Gram-positive bacterium (Bacillus cereus), a yeast (Saccharomyces cerevisiae), immune cells (murine macrophages), and an animal model (planarian Schmidtea mediterranea). These results underscored that AHL-based QS plays a key role in the capacity of C. violaceum to interact with micro- and macroorganisms and that quorum quenching can affect microbial population dynamics beyond AHL-producing bacteria and Gram-negative bacteria.
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Affiliation(s)
- Sonia Mion
- Aix Marseille University, Institut de Recherche pour le Développement, Assistance Publique - Hôpitaux de Marseille, Microbes Evolution Phylogeny and Infections, Institut Hospitalo-Universitaire-Méditerranée Infection, Marseille, France
| | | | | | | | | | - Eric Chabrière
- Aix Marseille University, Institut de Recherche pour le Développement, Assistance Publique - Hôpitaux de Marseille, Microbes Evolution Phylogeny and Infections, Institut Hospitalo-Universitaire-Méditerranée Infection, Marseille, France.
| | - Gérald Culioli
- Université de Toulon, MAPIEM, Toulon, France. .,Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale, UMR CNRS-IRD, Avignon Université, Aix-Marseille Université, Avignon, France.
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47
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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: 33] [Impact Index Per Article: 11.0] [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.
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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.
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48
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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.
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49
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Lakshmanan V, Sujith TN, Bansal D, Shivaprasad PV, Palakodeti D, Krishna S. Comprehensive annotation and characterization of planarian tRNA and tRNA-derived fragments (tRFs). RNA (NEW YORK, N.Y.) 2021; 27:477-495. [PMID: 33446492 PMCID: PMC7962491 DOI: 10.1261/rna.077701.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
tRNA-derived fragments (tRFs) have recently gained a lot of scientific interest due to their diverse regulatory roles in several cellular processes. However, their function in dynamic biological processes such as development and regeneration remains unexplored. Here, we show that tRFs are dynamically expressed during planarian regeneration, suggesting a possible role for these small RNAs in the regulation of regeneration. In order to characterize planarian tRFs, we first annotated 457 tRNAs in S. mediterranea combining two tRNA prediction algorithms. Annotation of tRNAs facilitated the identification of three main species of tRFs in planarians-the shorter tRF-5s and itRFs, and the abundantly expressed 5'-tsRNAs. Spatial profiling of tRFs in sequential transverse sections of planarians revealed diverse expression patterns of these small RNAs, including those that are enriched in the head and pharyngeal regions. Expression analysis of these tRF species revealed dynamic expression of these small RNAs over the course of regeneration suggesting an important role in planarian anterior and posterior regeneration. Finally, we show that 5'-tsRNA in planaria interact with all three SMEDWI proteins and an involvement of AGO1 in the processing of itRFs. In summary, our findings implicate a novel role for tRFs in planarian regeneration, highlighting their importance in regulating complex systemic processes. Our study adds to the catalog of posttranscriptional regulatory systems in planaria, providing valuable insights on the biogenesis and the function of tRFs in neoblasts and planarian regeneration.
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MESH Headings
- Algorithms
- Animals
- Argonaute Proteins/genetics
- Argonaute Proteins/metabolism
- Base Pairing
- Base Sequence
- Gene Expression Regulation
- Helminth Proteins/genetics
- Helminth Proteins/metabolism
- Molecular Sequence Annotation
- Nucleic Acid Conformation
- Planarians/genetics
- Planarians/metabolism
- RNA, Helminth/chemistry
- RNA, Helminth/classification
- RNA, Helminth/genetics
- RNA, Helminth/metabolism
- RNA, Small Untranslated/chemistry
- RNA, Small Untranslated/classification
- RNA, Small Untranslated/genetics
- RNA, Small Untranslated/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/classification
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Regeneration/genetics
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Affiliation(s)
- Vairavan Lakshmanan
- Institute for Stem Cell Science and Regenerative Medicine (inStem), 560065 Bangalore, India
- SASTRA University, 613401 Thanjavur, India
| | - T N Sujith
- National Centre for Biological Sciences (NCBS), 560065 Bangalore, India
| | - Dhiru Bansal
- Institute for Stem Cell Science and Regenerative Medicine (inStem), 560065 Bangalore, India
| | | | - Dasaradhi Palakodeti
- Institute for Stem Cell Science and Regenerative Medicine (inStem), 560065 Bangalore, India
| | - Srikar Krishna
- Institute for Stem Cell Science and Regenerative Medicine (inStem), 560065 Bangalore, India
- SASTRA University, 613401 Thanjavur, India
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50
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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.
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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.
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