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Song J, Ma J, Liu X, Huang Z, Li L, Li L, Luo L, Ni R, He J. The MRN complex maintains the biliary-derived hepatocytes in liver regeneration through ATR-Chk1 pathway. NPJ Regen Med 2023; 8:20. [PMID: 37024481 PMCID: PMC10079969 DOI: 10.1038/s41536-023-00294-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 03/23/2023] [Indexed: 04/08/2023] Open
Abstract
When the proliferation of residual hepatocytes is prohibited, biliary epithelial cells (BECs) transdifferentiate into nascent hepatocytes to accomplish liver regeneration. Despite significant interest in transdifferentiation, little is known about the maintenance of nascent hepatocytes in post-injured environments. Here, we perform an N-ethyl-N-nitrosourea (ENU) forward genetic screen and identify a mutant containing a nonsense mutation in the gene nibrin (nbn), which encodes a component of the Mre11-Rad50-Nbn (MRN) complex that activates DNA damage response (DDR). The regenerated hepatocytes cannot be maintained and exhibit apoptosis in the mutant. Mechanistically, the nbn mutation results in the abrogation of ATR-Chk1 signaling and accumulations of DNA damage in nascent hepatocytes, which eventually induces p53-mediated apoptosis. Furthermore, loss of rad50 or mre11a shows similar phenotypes. This study reveals that the activation of DDR by the MRN complex is essential for the survival of BEC-derived hepatocytes, addressing how to maintain nascent hepatocytes in the post-injured environments.
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Affiliation(s)
- Jingmei Song
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Jianlong Ma
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Xing Liu
- 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
| | - Lianghui Li
- 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
| | - Lingfei Luo
- 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.
| | - Jianbo He
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China.
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2
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Basheer F, Sertori R, Liongue C, Ward AC. Zebrafish: A Relevant Genetic Model for Human Primary Immunodeficiency (PID) Disorders? Int J Mol Sci 2023; 24:ijms24076468. [PMID: 37047441 PMCID: PMC10095346 DOI: 10.3390/ijms24076468] [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: 03/06/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/14/2023] Open
Abstract
Primary immunodeficiency (PID) disorders, also commonly referred to as inborn errors of immunity, are a heterogenous group of human genetic diseases characterized by defects in immune cell development and/or function. Since these disorders are generally uncommon and occur on a variable background profile of potential genetic and environmental modifiers, animal models are critical to provide mechanistic insights as well as to create platforms to underpin therapeutic development. This review aims to review the relevance of zebrafish as an alternative genetic model for PIDs. It provides an overview of the conservation of the zebrafish immune system and details specific examples of zebrafish models for a multitude of specific human PIDs across a range of distinct categories, including severe combined immunodeficiency (SCID), combined immunodeficiency (CID), multi-system immunodeficiency, autoinflammatory disorders, neutropenia and defects in leucocyte mobility and respiratory burst. It also describes some of the diverse applications of these models, particularly in the fields of microbiology, immunology, regenerative biology and oncology.
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Affiliation(s)
- Faiza Basheer
- School of Medicine, Deakin University, Geelong, VIC 3216, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC 3216, Australia
| | - Robert Sertori
- School of Medicine, Deakin University, Geelong, VIC 3216, Australia
| | - Clifford Liongue
- School of Medicine, Deakin University, Geelong, VIC 3216, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC 3216, Australia
| | - Alister C Ward
- School of Medicine, Deakin University, Geelong, VIC 3216, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC 3216, Australia
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Janssen E, Alosaimi MF, Alazami AM, Alsuliman A, Alaiya A, Al-Saud B, Al-Mousa H, Al-Zaid TJ, Smith E, Platt CD, Alruwaili H, Albanyan S, Al-Mayouf SM, Geha RS. A homozygous truncating mutation of FGL2 is associated with immune dysregulation. J Allergy Clin Immunol 2023; 151:572-578.e1. [PMID: 36243222 DOI: 10.1016/j.jaci.2022.10.006] [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: 07/06/2022] [Revised: 09/15/2022] [Accepted: 10/07/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND The type II transmembrane protein fibrinogen-like protein 2 (FGL2) plays critical roles in hemostasis and immune regulation. The C-terminal immunoregulatory domain of FGL2 can be secreted and is a mediator of regulatory T (Treg) cell suppression. Fgl2-/- mice develop autoantibodies and glomerulonephritis and have impaired Treg cell function. OBJECTIVE Our aim was to identify the genetic underpinning and immune function in a patient with childhood onset of leukocytoclastic vasculitis, systemic inflammation, and autoantibodies. METHODS Whole-exome sequencing was performed on patient genomic DNA. FGL2 protein expression was examined in HEK293 transfected cells by immunoblotting and in PBMCs by flow cytometry. T follicular helper cells and Treg cells were examined by flow cytometry. Treg cell suppression of T-cell proliferation was assessed in vitro. RESULTS The patient had a homozygous mutation in FGL2 (c.614_617del:p.V205fs), which led to the expression of a truncated FGL2 protein that preserves the N-terminal domain but lacks the C-terminal immunoregulatory domain. The patient had an increased percentage of circulating T follicular helper and Treg cells. The patient's Treg cells had impaired in vitro suppressive ability that was rescued by the addition of full-length FGL2. Unlike full-length FGL2, the truncated FGL2V205fs mutant failed to suppress T-cell proliferation. CONCLUSIONS We identified a homozygous mutation in FGL2 in a patient with immune dysregulation and impaired Treg cell function. Soluble FGL2 rescued the Treg cell defect, suggesting that it may provide a useful therapy for the patient.
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Affiliation(s)
- Erin Janssen
- Division of Immunology, Boston Children's Hospital and Harvard Medical School, Boston, Mass.
| | - Mohammad F Alosaimi
- Immunology Research Laboratory, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Anas M Alazami
- Translational Genomics, Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Abdullah Alsuliman
- Stem Cell and Tissue Re-Engineering Program, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ayodele Alaiya
- Stem Cell and Tissue Re-Engineering Program, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Bandar Al-Saud
- Department of Allergy and Immunology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hamoud Al-Mousa
- Department of Allergy and Immunology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Tariq Jassim Al-Zaid
- Department of Pathology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Emma Smith
- Division of Immunology, Boston Children's Hospital and Harvard Medical School, Boston, Mass
| | - Craig D Platt
- Division of Immunology, Boston Children's Hospital and Harvard Medical School, Boston, Mass
| | - Hibah Alruwaili
- Translational Genomics, Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sarah Albanyan
- Department of Allergy and Immunology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sulaiman M Al-Mayouf
- Department of Pediatric Rheumatology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia; College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
| | - Raif S Geha
- Division of Immunology, Boston Children's Hospital and Harvard Medical School, Boston, Mass.
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Surya A, Sarinay-Cenik E. Cell autonomous and non-autonomous consequences of deviations in translation machinery on organism growth and the connecting signalling pathways. Open Biol 2022; 12:210308. [PMID: 35472285 PMCID: PMC9042575 DOI: 10.1098/rsob.210308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 03/31/2022] [Indexed: 01/09/2023] Open
Abstract
Translation machinery is responsible for the production of cellular proteins; thus, cells devote the majority of their resources to ribosome biogenesis and protein synthesis. Single-copy loss of function in the translation machinery components results in rare ribosomopathy disorders, such as Diamond-Blackfan anaemia in humans and similar developmental defects in various model organisms. Somatic copy number alterations of translation machinery components are also observed in specific tumours. The organism-wide response to haploinsufficient loss-of-function mutations in ribosomal proteins or translation machinery components is complex: variations in translation machinery lead to reduced ribosome biogenesis, protein translation and altered protein homeostasis and cellular signalling pathways. Cells are affected both autonomously and non-autonomously by changes in translation machinery or ribosome biogenesis through cell-cell interactions and secreted hormones. We first briefly introduce the model organisms where mutants or knockdowns of protein synthesis and ribosome biogenesis are characterized. Next, we specifically describe observations in Caenorhabditis elegans and Drosophila melanogaster, where insufficient protein synthesis in a subset of cells triggers cell non-autonomous growth or apoptosis responses that affect nearby cells and tissues. We then cover the characterized signalling pathways that interact with ribosome biogenesis/protein synthesis machinery with an emphasis on their respective functions during organism development.
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Affiliation(s)
- Agustian Surya
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Elif Sarinay-Cenik
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
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Chen Z, Guo Q, Song G, Hou Y. Molecular regulation of hematopoietic stem cell quiescence. Cell Mol Life Sci 2022; 79:218. [PMID: 35357574 PMCID: PMC11072845 DOI: 10.1007/s00018-022-04200-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 02/07/2022] [Accepted: 02/07/2022] [Indexed: 12/19/2022]
Abstract
Hematopoietic stem cells (HSCs) are primarily dormant in a cell-cycle quiescence state to preserve their self-renewal capacity and long-term maintenance, which is essential for the homeostasis of hematopoietic system. Dysregulation of quiescence causes HSC dysfunction and may result in aberrant hematopoiesis (e.g., myelodysplastic syndrome and bone marrow failure syndromes) and leukemia transformation. Accumulating evidence indicates that both intrinsic molecular networks and extrinsic signals regulate HSC quiescence, including cell-cycle regulators, transcription factors, epigenetic factors, and niche factors. Further, the transition between quiescence and activation of HSCs is a continuous developmental path driven by cell metabolism (e.g., protein synthesis, glycolysis, oxidative phosphorylation, and autophagy). Elucidating the complex regulatory networks of HSC quiescence will expand the knowledge of HSC hemostasis and benefit for clinical HSC use. Here, we review the current understanding and progression on the molecular and metabolic regulation of HSC quiescence, providing a more complete picture regarding the mechanisms of HSC quiescence maintenance.
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Affiliation(s)
- Zhe Chen
- Institute of Life Sciences, Chongqing Medical University, Chongqing, 400016, China
- Department of Hematology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Qian Guo
- Institute of Life Sciences, Chongqing Medical University, Chongqing, 400016, China
- Department of Hematology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Guanbin Song
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China.
| | - Yu Hou
- Institute of Life Sciences, Chongqing Medical University, Chongqing, 400016, China.
- Department of Hematology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, 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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Ribosomes: An Exciting Avenue in Stem Cell Research. Stem Cells Int 2020; 2020:8863539. [PMID: 32695182 PMCID: PMC7362291 DOI: 10.1155/2020/8863539] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 02/07/2023] Open
Abstract
Stem cell research has focused on genomic studies. However, recent evidence has indicated the involvement of epigenetic regulation in determining the fate of stem cells. Ribosomes play a crucial role in epigenetic regulation, and thus, we focused on the role of ribosomes in stem cells. Majority of living organisms possess ribosomes that are involved in the translation of mRNA into proteins and promote cellular proliferation and differentiation. Ribosomes are stable molecular machines that play a role with changes in the levels of RNA during translation. Recent research suggests that specific ribosomes actively regulate gene expression in multiple cell types, such as stem cells. Stem cells have the potential for self-renewal and differentiation into multiple lineages and, thus, require high efficiency of translation. Ribosomes induce cellular transdifferentiation and reprogramming, and disrupted ribosome synthesis affects translation efficiency, thereby hindering stem cell function leading to cell death and differentiation. Stem cell function is regulated by ribosome-mediated control of stem cell-specific gene expression. In this review, we have presented a detailed discourse on the characteristics of ribosomes in stem cells. Understanding ribosome biology in stem cells will provide insights into the regulation of stem cell function and cellular reprogramming.
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Ribosome and Translational Control in Stem Cells. Cells 2020; 9:cells9020497. [PMID: 32098201 PMCID: PMC7072746 DOI: 10.3390/cells9020497] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/11/2020] [Accepted: 02/17/2020] [Indexed: 12/16/2022] Open
Abstract
Embryonic stem cells (ESCs) and adult stem cells (ASCs) possess the remarkable capacity to self-renew while remaining poised to differentiate into multiple progenies in the context of a rapidly developing embryo or in steady-state tissues, respectively. This ability is controlled by complex genetic programs, which are dynamically orchestrated at different steps of gene expression, including chromatin remodeling, mRNA transcription, processing, and stability. In addition to maintaining stem cell homeostasis, these molecular processes need to be rapidly rewired to coordinate complex physiological modifications required to redirect cell fate in response to environmental clues, such as differentiation signals or tissue injuries. Although chromatin remodeling and mRNA expression have been extensively studied in stem cells, accumulating evidence suggests that stem cell transcriptomes and proteomes are poorly correlated and that stem cell properties require finely tuned protein synthesis. In addition, many studies have shown that the biogenesis of the translation machinery, the ribosome, is decisive for sustaining ESC and ASC properties. Therefore, these observations emphasize the importance of translational control in stem cell homeostasis and fate decisions. In this review, we will provide the most recent literature describing how ribosome biogenesis and translational control regulate stem cell functions and are crucial for accommodating proteome remodeling in response to changes in stem cell fate.
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