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Unterweger IA, Klepstad J, Hannezo E, Lundegaard PR, Trusina A, Ober EA. Lineage tracing identifies heterogeneous hepatoblast contribution to cell lineages and postembryonic organ growth dynamics. PLoS Biol 2023; 21:e3002315. [PMID: 37792696 PMCID: PMC10550115 DOI: 10.1371/journal.pbio.3002315] [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: 01/18/2023] [Accepted: 08/29/2023] [Indexed: 10/06/2023] Open
Abstract
To meet the physiological demands of the body, organs need to establish a functional tissue architecture and adequate size as the embryo develops to adulthood. In the liver, uni- and bipotent progenitor differentiation into hepatocytes and biliary epithelial cells (BECs), and their relative proportions, comprise the functional architecture. Yet, the contribution of individual liver progenitors at the organ level to both fates, and their specific proportion, is unresolved. Combining mathematical modelling with organ-wide, multispectral FRaeppli-NLS lineage tracing in zebrafish, we demonstrate that a precise BEC-to-hepatocyte ratio is established (i) fast, (ii) solely by heterogeneous lineage decisions from uni- and bipotent progenitors, and (iii) independent of subsequent cell type-specific proliferation. Extending lineage tracing to adulthood determined that embryonic cells undergo spatially heterogeneous three-dimensional growth associated with distinct environments. Strikingly, giant clusters comprising almost half a ventral lobe suggest lobe-specific dominant-like growth behaviours. We show substantial hepatocyte polyploidy in juveniles representing another hallmark of postembryonic liver growth. Our findings uncover heterogeneous progenitor contributions to tissue architecture-defining cell type proportions and postembryonic organ growth as key mechanisms forming the adult liver.
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Affiliation(s)
- Iris. A. Unterweger
- University of Copenhagen, NNF Center for Stem Cell Biology (DanStem), Copenhagen N, Denmark
- University of Copenhagen, Department of Biomedical Sciences, Copenhagen N, Denmark
| | - Julie Klepstad
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Andalusian Center for Developmental Biology, CSIC, University Pablo de Olavide, Seville, Spain
| | - Edouard Hannezo
- Institute of Science and Technology, Klosterneuburg, Austria
| | - Pia R. Lundegaard
- University of Copenhagen, Department of Biomedical Sciences, Copenhagen N, Denmark
| | - Ala Trusina
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Elke A. Ober
- University of Copenhagen, NNF Center for Stem Cell Biology (DanStem), Copenhagen N, Denmark
- University of Copenhagen, Department of Biomedical Sciences, Copenhagen N, Denmark
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Ma J, Yang Z, Huang Z, Li L, Huang J, Chen J, Ni R, Luo L, He J. Rngtt governs biliary-derived liver regeneration initiation by transcriptional regulation of mTORC1 and Dnmt1 in zebrafish. Hepatology 2023; 78:167-178. [PMID: 36724876 DOI: 10.1097/hep.0000000000000186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/23/2022] [Indexed: 02/03/2023]
Abstract
In cases of end-stage liver diseases, the proliferation of existing hepatocytes is compromised, a feature of human chronic liver disease, in which most hepatocytes are dysfunctional. So far, liver transplantation represents the only curative therapeutic solution for advanced liver diseases, and the shortage of donor organs leads to high morbidity and mortality worldwide. The promising treatment is to prompt the biliary epithelial cells (BECs) transdifferentiation. However, the critical factors governing the initiation of BEC-derived liver regeneration are largely unknown. The zebrafish has advantages in large-scale genetic screens to identify the critical factors involved in liver regeneration. Here, we combined N-ethyl-N-nitrosourea screen, positional cloning, transgenic lines, antibody staining, and in situ hybridization methods and identified a liver regeneration defect mutant ( lrd ) using the zebrafish extensive liver injury model. Through positional cloning and genomic sequencing, we mapped the mutation site to rngtt . Loss of rngtt leads to the defects of BEC dedifferentiation, bipotential progenitor cell activation, and cell proliferation in the initiation stage of liver regeneration. The transdifferentiation from BECs to hepatocytes did not occur even at the late stage of liver regeneration. Mechanically, Rngtt transcriptionally regulates the attachment of mRNA cap to mTOR complex 1 (mTORC1) components and dnmt1 to maintain the activation of mTORC1 and DNA methylation in BECs after severe liver injury and prompt BEC to hepatocyte conversion. Furthermore, rptor and dnmt1 mutants displayed the same liver regeneration defects as rngtt mutation. In conclusion, our results suggest Rngtt is a new factor that initiates BEC-derived liver regeneration.
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Affiliation(s)
- Jianlong Ma
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Zhuolin Yang
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Zhuofu Huang
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Linke Li
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Jingliang Huang
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Jingying Chen
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
- University of Chinese Academy of Sciences (Chongqing), Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Beibei, Chongqing, China
| | - Rui Ni
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Lingfei Luo
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Jianbo He
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
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YAP affects the efficacy of liver progenitor cells transplantation in CCl4-induced acute liver injury. Biochem Biophys Res Commun 2022; 634:129-137. [DOI: 10.1016/j.bbrc.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 09/27/2022] [Accepted: 10/01/2022] [Indexed: 11/16/2022]
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Lalonde RL, Kemmler CL, Riemslagh FW, Aman AJ, Kresoja-Rakic J, Moran HR, Nieuwenhuize S, Parichy DM, Burger A, Mosimann C. Heterogeneity and genomic loci of ubiquitous transgenic Cre reporter lines in zebrafish. Dev Dyn 2022; 251:1754-1773. [PMID: 35582941 PMCID: PMC10069295 DOI: 10.1002/dvdy.499] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The most-common strategy for zebrafish Cre/lox-mediated lineage labeling experiments combines ubiquitously expressed, lox-based Switch reporter transgenes with tissue-specific Cre or 4-OH-Tamoxifen-inducible CreERT2 driver lines. Although numerous Cre driver lines have been produced, only a few broadly expressed Switch reporters exist in zebrafish and their generation by random transgene integration has been challenging due to position-effect sensitivity of the lox-flanked recombination cassettes. Here, we compare commonly used Switch reporter lines for their recombination efficiency and reporter expression pattern during zebrafish development. RESULTS Using different experimental setups, we show that ubi:Switch and hsp70l:Switch outperform current generations of the two additional Switch reporters actb2:BFP-DsRed and actb2:Stop-DsRed. Our comparisons also document preferential Cre-dependent recombination of ubi:Switch and hsp70l:Switch in distinct zebrafish tissues at early developmental stages. To investigate what genomic features may influence Cre accessibility and lox recombination efficiency in highly functional Switch lines, we mapped these transgenes and charted chromatin dynamics at their integration sites. CONCLUSIONS Our data documents the heterogeneity among lox-based Switch transgenes toward informing suitable transgene selection for lineage labeling experiments. Our work further proposes that ubi:Switch and hsp70l:Switch define genomic integration sites suitable for universal transgene or switch reporter knock-in in zebrafish.
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Affiliation(s)
- Robert L Lalonde
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Cassie L Kemmler
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Fréderike W Riemslagh
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Andrew J Aman
- Department of Biology, University of Virginia, Charlottesville, Virginia, USA.,Department of Biology and Department of Cell Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Jelena Kresoja-Rakic
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hannah R Moran
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Susan Nieuwenhuize
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - David M Parichy
- Department of Biology, University of Virginia, Charlottesville, Virginia, USA.,Department of Biology and Department of Cell Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Alexa Burger
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Christian Mosimann
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
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DNA methylation maintenance at the p53 locus initiates biliary-mediated liver regeneration. NPJ Regen Med 2022; 7:21. [PMID: 35351894 PMCID: PMC8964678 DOI: 10.1038/s41536-022-00217-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 03/01/2022] [Indexed: 12/13/2022] Open
Abstract
In cases of extensive liver injury, biliary epithelial cells (BECs) dedifferentiate into bipotential progenitor cells (BPPCs), then redifferentiate into hepatocytes and BECs to accomplish liver regeneration. Whether epigenetic regulations, particularly DNA methylation maintenance enzymes, play a role in this biliary-mediated liver regeneration remains unknown. Here we show that in response to extensive hepatocyte damages, expression of dnmt1 is upregulated in BECs to methylate DNA at the p53 locus, which represses p53 transcription, and in turn, derepresses mTORC1 signaling to activate BEC dedifferentiation. After BEC dedifferentiation and BPPC formation, DNA methylation at the p53 locus maintains in BPPCs to continue blocking p53 transcription, which derepresses Bmp signaling to induce BPPC redifferentiation. Thus, this study reveals promotive roles and mechanisms of DNA methylation at the p53 locus in both dedifferentiation and redifferentiation stages of biliary-mediated liver regeneration, implicating DNA methylation and p53 as potential targets to stimulate regeneration after extensive liver injury.
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Pu W, Zhou B. Hepatocyte generation in liver homeostasis, repair, and regeneration. CELL REGENERATION (LONDON, ENGLAND) 2022; 11:2. [PMID: 34989894 PMCID: PMC8739411 DOI: 10.1186/s13619-021-00101-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 10/22/2021] [Indexed: 12/29/2022]
Abstract
The liver has remarkable capability to regenerate, employing mechanism to ensure the stable liver-to-bodyweight ratio for body homeostasis. The source of this regenerative capacity has received great attention over the past decade yet still remained controversial currently. Deciphering the sources for hepatocytes provides the basis for understanding tissue regeneration and repair, and also illustrates new potential therapeutic targets for treating liver diseases. In this review, we describe recent advances in genetic lineage tracing studies over liver stem cells, hepatocyte proliferation, and cell lineage conversions or cellular reprogramming. This review will also evaluate the technical strengths and limitations of methods used for studies on hepatocyte generation and cell fate plasticity in liver homeostasis, repair and regeneration.
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Affiliation(s)
- Wenjuan Pu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Bin Zhou
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China. .,School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China. .,School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
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Zhang W, Wu C, Ni R, Yang Q, Luo L, He J. Formimidoyltransferase cyclodeaminase prevents the starvation-induced liver hepatomegaly and dysfunction through downregulating mTORC1. PLoS Genet 2021; 17:e1009980. [PMID: 34941873 PMCID: PMC8741050 DOI: 10.1371/journal.pgen.1009980] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 01/07/2022] [Accepted: 12/06/2021] [Indexed: 11/18/2022] Open
Abstract
The liver is a crucial center in the regulation of energy homeostasis under starvation. Although downregulation of mammalian target of rapamycin complex 1 (mTORC1) has been reported to play pivotal roles in the starvation responses, the underpinning mechanisms in particular upstream factors that downregulate mTORC1 remain largely unknown. To identify genetic variants that cause liver energy disorders during starvation, we conduct a zebrafish forward genetic screen. We identify a liver hulk (lvh) mutant with normal liver under feeding, but exhibiting liver hypertrophy under fasting. The hepatomegaly in lvh is caused by enlarged hepatocyte size and leads to liver dysfunction as well as limited tolerance to starvation. Positional cloning reveals that lvh phenotypes are caused by mutation in the ftcd gene, which encodes the formimidoyltransferase cyclodeaminase (FTCD). Further studies show that in response to starvation, the phosphorylated ribosomal S6 protein (p-RS6), a downstream effector of mTORC1, becomes downregulated in the wild-type liver, but remains at high level in lvh. Inhibition of mTORC1 by rapamycin rescues the hepatomegaly and liver dysfunction of lvh. Thus, we characterize the roles of FTCD in starvation response, which acts as an important upstream factor to downregulate mTORC1, thus preventing liver hypertrophy and dysfunction. Under starvation, the liver initiates a series of metabolic adaptations to maintain energy homeostasis that is critical for survival. During this process, mTORC1 pathway is downregulated to reduce anabolism and promote catabolism, ensuring adequate usage of limited resources. However, mechanisms underlying the downregulation of mTORC1 remain incompletely understood. In a zebrafish genetic screen aiming to characterize factors important for starvation response in the liver, we identify an ftcd mutation that causes liver hypertrophy and dysfunction under fasting. FTCD acts upstream to inactivate mTORC1 in response to starvation. Our work reveals previously unappreciated roles of FTCD in the responses to energy stress through modulating mTORC1 activities, moreover implicates a potential liver disorder risk of FTCD deficiency under the circumstances of starvation.
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Affiliation(s)
- Wenfeng Zhang
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Yubei, Chongqing, China
| | - Chaoying Wu
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Rui Ni
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Qifen Yang
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Lingfei Luo
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
- * E-mail: (LL); (JH)
| | - Jianbo He
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
- * E-mail: (LL); (JH)
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Liver Regeneration and Cell Transplantation for End-Stage Liver Disease. Biomolecules 2021; 11:biom11121907. [PMID: 34944550 PMCID: PMC8699389 DOI: 10.3390/biom11121907] [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: 11/15/2021] [Revised: 12/12/2021] [Accepted: 12/14/2021] [Indexed: 02/06/2023] Open
Abstract
Liver transplantation is the only curative option for end-stage liver disease; however, the limitations of liver transplantation require further research into other alternatives. Considering that liver regeneration is prevalent in liver injury settings, regenerative medicine is suggested as a promising therapeutic strategy for end-stage liver disease. Upon the source of regenerating hepatocytes, liver regeneration could be divided into two categories: hepatocyte-driven liver regeneration (typical regeneration) and liver progenitor cell-driven liver regeneration (alternative regeneration). Due to the massive loss of hepatocytes, the alternative regeneration plays a vital role in end-stage liver disease. Advances in knowledge of liver regeneration and tissue engineering have accelerated the progress of regenerative medicine strategies for end-stage liver disease. In this article, we generally reviewed the recent findings and current knowledge of liver regeneration, mainly regarding aspects of the histological basis of regeneration, histogenesis and mechanisms of hepatocytes' regeneration. In addition, this review provides an update on the regenerative medicine strategies for end-stage liver disease. We conclude that regenerative medicine is a promising therapeutic strategy for end-stage liver disease. However, further studies are still required.
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