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Ko JM, Reginato W, Wolff A, Lobo D. Mechanistic regulation of planarian shape during growth and degrowth. Development 2024; 151:dev202353. [PMID: 38619319 PMCID: PMC11128284 DOI: 10.1242/dev.202353] [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: 09/15/2023] [Accepted: 04/08/2024] [Indexed: 04/16/2024]
Abstract
Adult planarians can grow when fed and degrow (shrink) when starved while maintaining their whole-body shape. It is unknown how the morphogens patterning the planarian axes are coordinated during feeding and starvation or how they modulate the necessary differential tissue growth or degrowth. Here, we investigate the dynamics of planarian shape together with a theoretical study of the mechanisms regulating whole-body proportions and shape. We found that the planarian body proportions scale isometrically following similar linear rates during growth and degrowth, but that fed worms are significantly wider than starved worms. By combining a descriptive model of planarian shape and size with a mechanistic model of anterior-posterior and medio-lateral signaling calibrated with a novel parameter optimization methodology, we theoretically demonstrate that the feedback loop between these positional information signals and the shape they control can regulate the planarian whole-body shape during growth. Furthermore, the computational model produced the correct shape and size dynamics during degrowth as a result of a predicted increase in apoptosis rate and pole signal during starvation. These results offer mechanistic insights into the dynamic regulation of whole-body morphologies.
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Affiliation(s)
- Jason M. Ko
- Department of Biological Sciences, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Waverly Reginato
- Department of Biological Sciences, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Andrew Wolff
- Department of Biological Sciences, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Daniel Lobo
- Department of Biological Sciences, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
- Greenebaum Comprehensive Cancer Center and Center for Stem Cell Biology & Regenerative Medicine, University of Maryland, School of Medicine, 22 S. Greene Street, Baltimore, MD 21201, USA
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2
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Hayasaka O, Shibukawa M, Kamei H. Cellular Energy Sensor Sirt1 Augments Mapk Signaling to Promote Hypoxia/Reoxygenation-Induced Catch-up Growth in Zebrafish Embryo. Zoolog Sci 2024; 41:21-31. [PMID: 38587514 DOI: 10.2108/zs230059] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/23/2023] [Indexed: 04/09/2024]
Abstract
Animal growth is blunted in adverse environments where catabolic metabolism dominates; however, when the adversity disappears, stunted animals rapidly catch up to age-equivalent body size. This phenomenon is called catch-up growth, which we observe in various animals. Since growth retardation and catch-up growth are sequential processes, catabolism or stress response molecules may remain active, especially immediately after growth resumes. Sirtuins (Sirt1-7) deacetylate target proteins in a nicotinamide adenine dinucleotide-dependent manner, and these enzymes govern diverse alleys of cellular functions. Here, we investigated the roles of Sirt1 and its close paralog Sirt2 in the hypoxia/reoxygenation-induced catch-up growth model using zebrafish embryos. Temporal blockade of Sirt1/2 significantly reduced the growth rate of the embryos in reoxygenation, but it was not evident in constant normoxia. Subsequent gene knockdown and chemical inhibition experiments demonstrated that Sirt1, but not Sirt2, was required for the catchup growth. Inhibition of Sirt1 significantly reduced the activity of mitogen-activated kinase (Mapk) of embryos in the reoxygenation condition. In addition, co-inhibition of Sirt1- and Igf-signaling did not further reduce the body growth or Mapk activation compared to those of the Igf-signaling-alone-inhibited embryos. Furthermore, in the reoxygenation condition, Sirt1- or Igf-signaling inhibition similarly blunted Mapk activity, especially in anterior tissues and trunk muscle, where the sirt1 expression was evident in the catching-up embryos. These results suggest that the catch-up growth requires Sirt1 action to activate the somatotropic Mapk pathway, likely by modifying the Igf-signaling.
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Affiliation(s)
- Oki Hayasaka
- Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Mukaze Shibukawa
- Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
- Ikedamohando Co., Ltd., Nakaniikawa-gun, Toyama 930-0365, Japan
| | - Hiroyasu Kamei
- Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan,
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3
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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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Abel C, Powers K, Gurung G, Pellettieri J. Defined diets for freshwater planarians. Dev Dyn 2022; 251:390-402. [PMID: 34258816 PMCID: PMC8758798 DOI: 10.1002/dvdy.400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/02/2021] [Accepted: 07/08/2021] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Planarian flatworms are popular invertebrate models for basic research on stem cell biology and regeneration. These animals are commonly maintained on a diet of homogenized calf liver or boiled egg yolk in the laboratory, introducing a source of uncontrolled experimental variability. RESULTS Here, we report the development of defined diets, prepared entirely from standardized, commercially sourced ingredients, for the freshwater species Schmidtea mediterranea, Dugesia japonica, and Girardia dorotocephala. These food sources provide an opportunity to test the effects of specific nutritional variables on biological phenomena of interest. Defined diet consumption was not sufficient for growth and only partially induced the increase in stem cell division that normally accompanies feeding, suggesting these responses are not solely determined by caloric intake. Our defined diet formulations enable delivery of double-stranded RNA for gene knockdown in a manner that provides unique advantages in some experimental contexts. We also present a new approach for preserving tissue integrity during hydrogen peroxide bleaching of liver-fed animals. CONCLUSIONS These tools will empower research on the connections between diet, metabolism, and stem cell biology in the experimentally tractable planarian system.
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Affiliation(s)
- Chris Abel
- Department of Biology, Keene State College, Keene, NH, USA
| | - Kaleigh Powers
- Department of Biology, Keene State College, Keene, NH, USA
| | - Gargi Gurung
- Department of Biology, Keene State College, Keene, NH, USA
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Abstract
In the planarian field, two techniques are mostly used for protein detection: immunohistochemistry (IHC) and western blotting. While IHC is great for visualizing the spatial distribution of proteins in whole organisms, it has limitations in antibody availability and issues related to nonspecific expression. The use of western blotting can circumvent nonspecific expression, providing a dependable way to quantify proteins of interest. Here, we present a standardized, easily reproducible protocol with details on protein extractions of whole planarians and western blotting. For complete details on the use and execution of this protocol, please refer to Ziman et al. (2020a). Easy and dependable way to assess protein levels in planarians Extraction and measurements of total proteins from entire organisms Alternative approach to staining with high background in whole mount
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Affiliation(s)
- Benjamin Ziman
- Department of Molecular & Cell Biology, University of California, Merced, CA, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, CA, USA
| | - Néstor J Oviedo
- Department of Molecular & Cell Biology, University of California, Merced, CA, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, CA, USA.,Health Sciences Research Institute, University of California, Merced, CA, USA
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Analysis of Fox genes in Schmidtea mediterranea reveals new families and a conserved role of Smed-foxO in controlling cell death. Sci Rep 2021; 11:2947. [PMID: 33536473 PMCID: PMC7859237 DOI: 10.1038/s41598-020-80627-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 12/18/2020] [Indexed: 01/30/2023] Open
Abstract
The forkhead box (Fox) genes encode transcription factors that control several key aspects of development. Present in the ancestor of all eukaryotes, Fox genes underwent several duplications followed by loss and diversification events that gave rise to the current 25 families. However, few Fox members have been identified from the Lophotrochozoa clade, and specifically from planarians, which are a unique model for understanding development, due to the striking plasticity of the adult. The aim of this study was to identify and perform evolutionary and functional studies of the Fox genes of lophotrochozoan species and, specifically, of the planarian Schmidtea mediterranea. Generating a pipeline for identifying Forkhead domains and using phylogenetics allowed us the phylogenetic reconstruction of Fox genes. We corrected the annotation for misannotated genes and uncovered a new family, the QD, present in all metazoans. According to the new phylogeny, the 27 Fox genes found in Schmidtea mediterranea were classified into 12 families. In Platyhelminthes, family losses were accompanied by extensive gene diversification and the appearance of specific families, the A(P) and N(P). Among the newly identified planarian Fox genes, we found a single copy of foxO, which shows an evolutionary conserved role in controlling cell death.
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Maciel EI, Valle Arevalo A, Ziman B, Nobile CJ, Oviedo NJ. Epithelial Infection With Candida albicans Elicits a Multi-System Response in Planarians. Front Microbiol 2021; 11:629526. [PMID: 33519792 PMCID: PMC7840899 DOI: 10.3389/fmicb.2020.629526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 12/22/2020] [Indexed: 11/13/2022] Open
Abstract
Candida albicans is one of the most common fungal pathogens of humans. Prior work introduced the planarian Schmidtea mediterranea as a new model system to study the host response to fungal infection at the organismal level. In the current study, we analyzed host-pathogen changes that occurred in situ during early infection with C. albicans. We found that the transcription factor Bcr1 and its downstream adhesin Als3 are required for C. albicans to adhere to and colonize the planarian epithelial surface, and that adherence of C. albicans triggers a multi-system host response that is mediated by the Dectin signaling pathway. This infection response is characterized by two peaks of stem cell divisions and transcriptional changes in differentiated tissues including the nervous and the excretory systems. This response bears some resemblance to a wound-like response to physical injury; however, it takes place without visible tissue damage and it engages a distinct set of progenitor cells. Overall, we identified two C. albicans proteins that mediate epithelial infection of planarians and a comprehensive host response facilitated by diverse tissues to effectively clear the infection.
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Affiliation(s)
- Eli Isael Maciel
- Department of Molecular & Cell Biology, University of California, Merced, Merced, CA, United States.,Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, CA, United States
| | - Ashley Valle Arevalo
- Department of Molecular & Cell Biology, University of California, Merced, Merced, CA, United States.,Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, CA, United States
| | - Benjamin Ziman
- Department of Molecular & Cell Biology, University of California, Merced, Merced, CA, United States.,Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, CA, United States
| | - Clarissa J Nobile
- Department of Molecular & Cell Biology, University of California, Merced, Merced, CA, United States.,Health Sciences Research Institute, University of California, Merced, Merced, CA, United States
| | - Néstor J Oviedo
- Department of Molecular & Cell Biology, University of California, Merced, Merced, CA, United States.,Health Sciences Research Institute, University of California, Merced, Merced, CA, United States
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Ziman B, Barghouth PG, Maciel EI, Oviedo NJ. TRAF-like Proteins Regulate Cellular Survival in the Planarian Schmidtea mediterranea. iScience 2020; 23:101665. [PMID: 33134895 PMCID: PMC7586133 DOI: 10.1016/j.isci.2020.101665] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/31/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022] Open
Abstract
Tissue homeostasis relies on the timely renewal of cells that have been damaged or have surpassed their biological age. Nonetheless, the underlying molecular mechanism coordinating tissue renewal is unknown. The planarian Schmidtea mediterranea harbors a large population of stem cells that continuously divide to support the restoration of tissues throughout the body. Here, we identify that TNF Receptor Associated Factors (TRAFs) play critical roles in cellular survival during tissue repair in S. mediterranea. Disruption with RNA-interference of TRAF signaling results in rapid morphological defects and lethality within 2 weeks. The TRAF phenotype is accompanied by an increased number of mitoses and cell death. Our results also reveal TRAF signaling is required for proper regeneration of the nervous system. Taken together, we find functional conservation of TRAF-like proteins in S. mediterranea as they act as crucial regulators of cellular survival during tissue homeostasis and regeneration.
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Affiliation(s)
- Benjamin Ziman
- Department of Molecular and Cell Biology, University of California, Merced, CA 95343, USA
- Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
| | - Paul G. Barghouth
- Department of Molecular and Cell Biology, University of California, Merced, CA 95343, USA
- Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
| | - Eli Isael Maciel
- Department of Molecular and Cell Biology, University of California, Merced, CA 95343, USA
- Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
| | - Néstor J. Oviedo
- Department of Molecular and Cell Biology, University of California, Merced, CA 95343, USA
- Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
- Health Sciences Research Institute, University of California, Merced, CA 95343, USA
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