1
|
Liu S, Hur YH, Cai X, Cong Q, Yang Y, Xu C, Bilate AM, Gonzales KAU, Parigi SM, Cowley CJ, Hurwitz B, Luo JD, Tseng T, Gur-Cohen S, Sribour M, Omelchenko T, Levorse J, Pasolli HA, Thompson CB, Mucida D, Fuchs E. A tissue injury sensing and repair pathway distinct from host pathogen defense. Cell 2023; 186:2127-2143.e22. [PMID: 37098344 PMCID: PMC10321318 DOI: 10.1016/j.cell.2023.03.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 02/03/2023] [Accepted: 03/27/2023] [Indexed: 04/27/2023]
Abstract
Pathogen infection and tissue injury are universal insults that disrupt homeostasis. Innate immunity senses microbial infections and induces cytokines/chemokines to activate resistance mechanisms. Here, we show that, in contrast to most pathogen-induced cytokines, interleukin-24 (IL-24) is predominately induced by barrier epithelial progenitors after tissue injury and is independent of microbiome or adaptive immunity. Moreover, Il24 ablation in mice impedes not only epidermal proliferation and re-epithelialization but also capillary and fibroblast regeneration within the dermal wound bed. Conversely, ectopic IL-24 induction in the homeostatic epidermis triggers global epithelial-mesenchymal tissue repair responses. Mechanistically, Il24 expression depends upon both epithelial IL24-receptor/STAT3 signaling and hypoxia-stabilized HIF1α, which converge following injury to trigger autocrine and paracrine signaling involving IL-24-mediated receptor signaling and metabolic regulation. Thus, parallel to innate immune sensing of pathogens to resolve infections, epithelial stem cells sense injury signals to orchestrate IL-24-mediated tissue repair.
Collapse
Affiliation(s)
- Siqi Liu
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Yun Ha Hur
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Xin Cai
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Qian Cong
- McDermott Center for Human Growth and Development, Department of Biophysics, and Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yihao Yang
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Chiwei Xu
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Angelina M Bilate
- Laboratory of Mucosal Immunology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Kevin Andrew Uy Gonzales
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - S Martina Parigi
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Christopher J Cowley
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Brian Hurwitz
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Ji-Dung Luo
- Bioinformatics Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Tiffany Tseng
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Shiri Gur-Cohen
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Megan Sribour
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Tatiana Omelchenko
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - John Levorse
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Hilda Amalia Pasolli
- Electron Microscopy Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Craig B Thompson
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Daniel Mucida
- Laboratory of Mucosal Immunology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Elaine Fuchs
- Robin Chemers Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| |
Collapse
|
2
|
Fiore VF, Krajnc M, Quiroz FG, Levorse J, Pasolli HA, Shvartsman SY, Fuchs E. Mechanics of a multilayer epithelium instruct tumour architecture and function. Nature 2020; 585:433-439. [PMID: 32879493 DOI: 10.1038/s41586-020-2695-9] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 07/22/2020] [Indexed: 01/24/2023]
Abstract
Loss of normal tissue architecture is a hallmark of oncogenic transformation1. In developing organisms, tissues architectures are sculpted by mechanical forces during morphogenesis2. However, the origins and consequences of tissue architecture during tumorigenesis remain elusive. In skin, premalignant basal cell carcinomas form 'buds', while invasive squamous cell carcinomas initiate as 'folds'. Here, using computational modelling, genetic manipulations and biophysical measurements, we identify the biophysical underpinnings and biological consequences of these tumour architectures. Cell proliferation and actomyosin contractility dominate tissue architectures in monolayer, but not multilayer, epithelia. In stratified epidermis, meanwhile, softening and enhanced remodelling of the basement membrane promote tumour budding, while stiffening of the basement membrane promotes folding. Additional key forces stem from the stratification and differentiation of progenitor cells. Tumour-specific suprabasal stiffness gradients are generated as oncogenic lesions progress towards malignancy, which we computationally predict will alter extensile tensions on the tumour basement membrane. The pathophysiologic ramifications of this prediction are profound. Genetically decreasing the stiffness of basement membranes increases membrane tensions in silico and potentiates the progression of invasive squamous cell carcinomas in vivo. Our findings suggest that mechanical forces-exerted from above and below progenitors of multilayered epithelia-function to shape premalignant tumour architectures and influence tumour progression.
Collapse
Affiliation(s)
- Vincent F Fiore
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA
| | - Matej Krajnc
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.,Jozef Stefan Institute, Ljubljana, Slovenia
| | - Felipe Garcia Quiroz
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA.,Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - John Levorse
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA
| | - H Amalia Pasolli
- Electron Microscopy Resource Center, The Rockefeller University, New York, NY, USA
| | - Stanislav Y Shvartsman
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.,Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Elaine Fuchs
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA.
| |
Collapse
|
3
|
Matos I, Asare A, Levorse J, Ouspenskaia T, de la Cruz-Racelis J, Schuhmacher LN, Fuchs E. Progenitors oppositely polarize WNT activators and inhibitors to orchestrate tissue development. eLife 2020; 9:e54304. [PMID: 32310087 PMCID: PMC7224699 DOI: 10.7554/elife.54304] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/17/2020] [Indexed: 12/12/2022] Open
Abstract
To spatially co-exist and differentially specify fates within developing tissues, morphogenetic cues must be correctly positioned and interpreted. Here, we investigate mouse hair follicle development to understand how morphogens operate within closely spaced, fate-diverging progenitors. Coupling transcriptomics with genetics, we show that emerging hair progenitors produce both WNTs and WNT inhibitors. Surprisingly, however, instead of generating a negative feedback loop, the signals oppositely polarize, establishing sharp boundaries and consequently a short-range morphogen gradient that we show is essential for three-dimensional pattern formation. By establishing a morphogen gradient at the cellular level, signals become constrained. The progenitor preserves its WNT signaling identity and maintains WNT signaling with underlying mesenchymal neighbors, while its overlying epithelial cells become WNT-restricted. The outcome guarantees emergence of adjacent distinct cell types to pattern the tissue.
Collapse
Affiliation(s)
- Irina Matos
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - Amma Asare
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - John Levorse
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - Tamara Ouspenskaia
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - June de la Cruz-Racelis
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | | | - Elaine Fuchs
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| |
Collapse
|
4
|
Quiroz FG, Fiore VF, Levorse J, Polak L, Wong E, Pasolli HA, Fuchs E. Liquid-liquid phase separation drives skin barrier formation. Science 2020; 367:367/6483/eaax9554. [PMID: 32165560 DOI: 10.1126/science.aax9554] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 11/20/2019] [Accepted: 01/22/2020] [Indexed: 12/20/2022]
Abstract
At the body surface, skin's stratified squamous epithelium is challenged by environmental extremes. The surface of the skin is composed of enucleated, flattened surface squames. They derive from underlying, transcriptionally active keratinocytes that display filaggrin-containing keratohyalin granules (KGs) whose function is unclear. Here, we found that filaggrin assembles KGs through liquid-liquid phase separation. The dynamics of phase separation governed terminal differentiation and were disrupted by human skin barrier disease-associated mutations. We used fluorescent sensors to investigate endogenous phase behavior in mice. Phase transitions during epidermal stratification crowded cellular spaces with liquid-like KGs whose coalescence was restricted by keratin filament bundles. We imaged cells as they neared the skin surface and found that environmentally regulated KG phase dynamics drive squame formation. Thus, epidermal structure and function are driven by phase-separation dynamics.
Collapse
Affiliation(s)
- Felipe Garcia Quiroz
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Vincent F Fiore
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - John Levorse
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Lisa Polak
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Ellen Wong
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - H Amalia Pasolli
- Electron Microscopy Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Elaine Fuchs
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA.
| |
Collapse
|
5
|
Gur-Cohen S, Yang H, Baksh SC, Miao Y, Levorse J, Kataru RP, Liu X, de la Cruz-Racelis J, Mehrara BJ, Fuchs E. Stem cell-driven lymphatic remodeling coordinates tissue regeneration. Science 2019; 366:1218-1225. [PMID: 31672914 PMCID: PMC6996853 DOI: 10.1126/science.aay4509] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/15/2019] [Indexed: 12/20/2022]
Abstract
Tissues rely on stem cells (SCs) for homeostasis and wound repair. SCs reside in specialized microenvironments (niches) whose complexities and roles in orchestrating tissue growth are still unfolding. Here, we identify lymphatic capillaries as critical SC-niche components. In skin, lymphatics form intimate networks around hair follicle (HF) SCs. When HFs regenerate, lymphatic-SC connections become dynamic. Using a mouse model, we unravel a secretome switch in SCs that controls lymphatic behavior. Resting SCs express angiopoietin-like protein 7 (Angptl7), promoting lymphatic drainage. Activated SCs switch to Angptl4, triggering transient lymphatic dissociation and reduced drainage. When lymphatics are perturbed or the secretome switch is disrupted, HFs cycle precociously and tissue regeneration becomes asynchronous. In unearthing lymphatic capillaries as a critical SC-niche element, we have learned how SCs coordinate their activity across a tissue.
Collapse
Affiliation(s)
- Shiri Gur-Cohen
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Hanseul Yang
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Sanjeethan C Baksh
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Yuxuan Miao
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - John Levorse
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Raghu P Kataru
- Department of Surgery, Plastic and Reconstructive Surgery Service, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Xiaolei Liu
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute, Northwestern University, Chicago, IL 60611, USA
| | - June de la Cruz-Racelis
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Babak J Mehrara
- Department of Surgery, Plastic and Reconstructive Surgery Service, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Elaine Fuchs
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA.
| |
Collapse
|
6
|
Laurin M, Gomez NC, Levorse J, Sendoel A, Sribour M, Fuchs E. An RNAi screen unravels the complexities of Rho GTPase networks in skin morphogenesis. eLife 2019; 8:e50226. [PMID: 31556874 PMCID: PMC6768663 DOI: 10.7554/elife.50226] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/24/2019] [Indexed: 01/09/2023] Open
Abstract
During mammalian embryogenesis, extensive cellular remodeling is needed for tissue morphogenesis. As effectors of cytoskeletal dynamics, Rho GTPases and their regulators are likely involved, but their daunting complexity has hindered progress in dissecting their functions. We overcome this hurdle by employing high throughput in utero RNAi-mediated screening to identify key Rho regulators of skin morphogenesis. Our screen unveiled hitherto unrecognized roles for Rho-mediated cytoskeletal remodeling events that impact hair follicle specification, differentiation, downgrowth and planar cell polarity. Coupling our top hit with gain/loss-of-function genetics, interactome proteomics and tissue imaging, we show that RHOU, an atypical Rho, governs the cytoskeletal-junction dynamics that establish columnar shape and planar cell polarity in epidermal progenitors. Conversely, RHOU downregulation is required to remodel to a conical cellular shape that enables hair bud invagination and downgrowth. Our findings underscore the power of coupling screens with proteomics to unravel the physiological significance of complex gene families.
Collapse
Affiliation(s)
- Melanie Laurin
- Robin Neustein Laboratory of Mammalian Cell Biology and DevelopmentHoward Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - Nicholas C Gomez
- Robin Neustein Laboratory of Mammalian Cell Biology and DevelopmentHoward Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - John Levorse
- Robin Neustein Laboratory of Mammalian Cell Biology and DevelopmentHoward Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - Ataman Sendoel
- Robin Neustein Laboratory of Mammalian Cell Biology and DevelopmentHoward Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - Megan Sribour
- Robin Neustein Laboratory of Mammalian Cell Biology and DevelopmentHoward Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| | - Elaine Fuchs
- Robin Neustein Laboratory of Mammalian Cell Biology and DevelopmentHoward Hughes Medical Institute, The Rockefeller UniversityNew YorkUnited States
| |
Collapse
|
7
|
Miao Y, Yang H, Levorse J, Yuan S, Polak L, Sribour M, Singh B, Rosenblum M, Fuchs E. Adaptive Immune Resistance Emerges from Tumor-Initiating Stem Cells. Cell 2019; 177:1172-1186.e14. [PMID: 31031009 PMCID: PMC6525024 DOI: 10.1016/j.cell.2019.03.025] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 02/11/2019] [Accepted: 03/11/2019] [Indexed: 12/29/2022]
Abstract
Our bodies are equipped with powerful immune surveillance to clear cancerous cells as they emerge. How tumor-initiating stem cells (tSCs) that form and propagate cancers equip themselves to overcome this barrier remains poorly understood. To tackle this problem, we designed a skin cancer model for squamous cell carcinoma (SCC) that can be effectively challenged by adoptive cytotoxic T cell transfer (ACT)-based immunotherapy. Using single-cell RNA sequencing (RNA-seq) and lineage tracing, we found that transforming growth factor β (TGF-β)-responding tSCs are superior at resisting ACT and form the root of tumor relapse. Probing mechanism, we discovered that during malignancy, tSCs selectively acquire CD80, a surface ligand previously identified on immune cells. Moreover, upon engaging cytotoxic T lymphocyte antigen-4 (CTLA4), CD80-expressing tSCs directly dampen cytotoxic T cell activity. Conversely, upon CTLA4- or TGF-β-blocking immunotherapies or Cd80 ablation, tSCs become vulnerable, diminishing tumor relapse after ACT treatment. Our findings place tSCs at the crux of how immune checkpoint pathways are activated.
Collapse
Affiliation(s)
- Yuxuan Miao
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| | - Hanseul Yang
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| | - John Levorse
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| | - Shaopeng Yuan
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| | - Lisa Polak
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| | - Megan Sribour
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| | - Bhuvanesh Singh
- Department of Surgery, Laboratory of Epithelial Cancer Biology and Molecular Cytology Core Facility, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Michael Rosenblum
- Department of Dermatology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Elaine Fuchs
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| |
Collapse
|
8
|
Ellis SJ, Gomez NC, Levorse J, Mertz AF, Ge Y, Fuchs E. Distinct modes of cell competition shape mammalian tissue morphogenesis. Nature 2019; 569:497-502. [PMID: 31092920 PMCID: PMC6638572 DOI: 10.1038/s41586-019-1199-y] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 04/11/2019] [Indexed: 12/16/2022]
Abstract
Cell competition (CC)—the sensing and elimination of less fit “loser” cells by neighbouring “winner” cells—was first described in Drosophila. Although proposed as a selection mechanism to optimize tissue and organ development, its evolutionary generality remains unclear. Here, by employing live-imaging, lineage-tracing, single cell transcriptomics and genetics, we unearth two intriguing CC mechanisms that sequentially shape and maintain stratified tissue architecture during mouse skin development. In early embryonic epidermis, winner progenitors within the single-layered epithelium kill and clear neighbouring losers by engulfment. Upon stratification and skin barrier formation, the basal layer instead expels losers through a homeostatic upward flux of differentiating progeny. This CC switch is physiologically relevant: when perturbed, so too is barrier formation. Our findings establish CC as a selective force to optimize vertebrate tissue function, and illuminate how a tissue dynamically adjusts CC strategies to preserve fitness as it encounters increased architectural complexity during morphogenesis.
Collapse
Affiliation(s)
- Stephanie J Ellis
- Howard Hughes Medical Institute, Robin Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA
| | - Nicholas C Gomez
- Howard Hughes Medical Institute, Robin Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA
| | - John Levorse
- Howard Hughes Medical Institute, Robin Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA
| | - Aaron F Mertz
- Howard Hughes Medical Institute, Robin Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA
| | - Yejing Ge
- Howard Hughes Medical Institute, Robin Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA
| | - Elaine Fuchs
- Howard Hughes Medical Institute, Robin Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY, USA.
| |
Collapse
|
9
|
Adam RC, Yang H, Ge Y, Lien WH, Wang P, Zhao Y, Polak L, Levorse J, Baksh SC, Zheng D, Fuchs E. Temporal Layering of Signaling Effectors Drives Chromatin Remodeling during Hair Follicle Stem Cell Lineage Progression. Cell Stem Cell 2018; 22:398-413.e7. [PMID: 29337183 DOI: 10.1016/j.stem.2017.12.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/11/2017] [Accepted: 12/08/2017] [Indexed: 11/29/2022]
Abstract
Tissue regeneration relies on resident stem cells (SCs), whose activity and lineage choices are influenced by the microenvironment. Exploiting the synchronized, cyclical bouts of tissue regeneration in hair follicles (HFs), we investigate how microenvironment dynamics shape the emergence of stem cell lineages. Employing epigenetic and ChIP-seq profiling, we uncover how signal-dependent transcription factors couple spatiotemporal cues to chromatin dynamics, thereby choreographing stem cell lineages. Using enhancer-driven reporters, mutagenesis, and genetics, we show that simultaneous BMP-inhibitory and WNT signals set the stage for lineage choices by establishing chromatin platforms permissive for diversification. Mechanistically, when binding of BMP effector pSMAD1 is relieved, enhancers driving HF-stem cell master regulators are silenced. Concomitantly, multipotent, lineage-fated enhancers silent in HF-stem cells become activated by exchanging WNT effectors TCF3/4 for LEF1. Throughout regeneration, lineage enhancers continue reliance upon LEF1 but then achieve specificity by accommodating additional incoming signaling effectors. Barriers to progenitor plasticity increase when diverse, signal-sensitive transcription factors shape LEF1-regulated enhancer dynamics.
Collapse
Affiliation(s)
- Rene C Adam
- Robin Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Hanseul Yang
- Robin Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Yejing Ge
- Robin Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Wen-Hui Lien
- Robin Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Ping Wang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yilin Zhao
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Lisa Polak
- Robin Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - John Levorse
- Robin Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Sanjeethan C Baksh
- Robin Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Departments of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Elaine Fuchs
- Robin Neustein Laboratory of Mammalian Development and Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
| |
Collapse
|
10
|
Asare A, Levorse J, Fuchs E. Coupling organelle inheritance with mitosis to balance growth and differentiation. Science 2017; 355:355/6324/eaah4701. [PMID: 28154022 DOI: 10.1126/science.aah4701] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/26/2016] [Accepted: 11/23/2016] [Indexed: 01/03/2023]
Abstract
Balancing growth and differentiation is essential to tissue morphogenesis and homeostasis. How imbalances arise in disease states is poorly understood. To address this issue, we identified transcripts differentially expressed in mouse basal epidermal progenitors versus their differentiating progeny and those altered in cancers. We used an in vivo RNA interference screen to unveil candidates that altered the equilibrium between the basal proliferative layer and suprabasal differentiating layers forming the skin barrier. We found that epidermal progenitors deficient in the peroxisome-associated protein Pex11b failed to segregate peroxisomes properly and entered a mitotic delay that perturbed polarized divisions and skewed daughter fates. Together, our findings unveil a role for organelle inheritance in mitosis, spindle alignment, and the choice of daughter progenitors to differentiate or remain stem-like.
Collapse
Affiliation(s)
- Amma Asare
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - John Levorse
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Elaine Fuchs
- Howard Hughes Medical Institute, Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA.
| |
Collapse
|
11
|
Sendoel A, Dunn JG, Rodriguez EH, Naik S, Gomez NC, Hurwitz B, Levorse J, Dill BD, Schramek D, Molina H, Weissman JS, Fuchs E. Abstract 4766: Translation from unconventional 5' start sites drives tumor initiation. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-4766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
How translational control impacts tumor-initiation and malignancy is just beginning to unfold. Here, we devise an epidermis-specific, in vivo ribosome profiling strategy to interrogate the translational landscape during the transition from normal homeostasis to malignancy. Inducing SOX2, broadly expressed in oncogenic RAS-associated cancers, we find that despite widespread reductions in translation and protein synthesis, certain oncogenic mRNAs are spared. Seeking mechanism, we find that during tumor-initiation, the translational apparatus is redirected towards unconventional upstream initiation sites, enhancing translational efficiency of oncogenic mRNAs. An in vivo RNAi screen of translational regulators revealed that dampening conventional EIF2 complexes has dire consequences for normal but not oncogenic growth. Conversely, we identify alternative initiation factors essential for cancer progression, where they mediate initiation at these upstream sites, differentially skewing translation and protein expression. Our findings unveil a hitherto unappreciated role of 5’UTR translation in cancer, and expose new targets for therapeutic intervention.
Citation Format: Ataman Sendoel, Joshua G. Dunn, Edwin H. Rodriguez, Shruti Naik, Nicholas C. Gomez, Brian Hurwitz, John Levorse, Brian D. Dill, Daniel Schramek, Henrik Molina, Jonathan S. Weissman, Elaine Fuchs. Translation from unconventional 5' start sites drives tumor initiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4766. doi:10.1158/1538-7445.AM2017-4766
Collapse
|
12
|
Keyes BE, Liu S, Asare A, Naik S, Levorse J, Polak L, Lu CP, Nikolova M, Pasolli HA, Fuchs E. Impaired Epidermal to Dendritic T Cell Signaling Slows Wound Repair in Aged Skin. Cell 2017; 167:1323-1338.e14. [PMID: 27863246 DOI: 10.1016/j.cell.2016.10.052] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 09/14/2016] [Accepted: 10/28/2016] [Indexed: 01/07/2023]
Abstract
Aged skin heals wounds poorly, increasing susceptibility to infections. Restoring homeostasis after wounding requires the coordinated actions of epidermal and immune cells. Here we find that both intrinsic defects and communication with immune cells are impaired in aged keratinocytes, diminishing their efficiency in restoring the skin barrier after wounding. At the wound-edge, aged keratinocytes display reduced proliferation and migration. They also exhibit a dampened ability to transcriptionally activate epithelial-immune crosstalk regulators, including a failure to properly activate/maintain dendritic epithelial T cells (DETCs), which promote re-epithelialization following injury. Probing mechanism, we find that aged keratinocytes near the wound edge don't efficiently upregulate Skints or activate STAT3. Notably, when epidermal Stat3, Skints, or DETCs are silenced in young skin, re-epithelialization following wounding is perturbed. These findings underscore epithelial-immune crosstalk perturbations in general, and Skints in particular, as critical mediators in the age-related decline in wound-repair.
Collapse
Affiliation(s)
| | - Siqi Liu
- The Rockefeller University, New York, NY 10065, USA
| | - Amma Asare
- The Rockefeller University, New York, NY 10065, USA
| | - Shruti Naik
- The Rockefeller University, New York, NY 10065, USA
| | - John Levorse
- The Rockefeller University, New York, NY 10065, USA
| | - Lisa Polak
- The Rockefeller University, New York, NY 10065, USA
| | | | | | | | - Elaine Fuchs
- The Rockefeller University, New York, NY 10065, USA.
| |
Collapse
|
13
|
Yang H, Schramek D, Adam R, Levorse J, Keyes B, Wang P, Zheng D, Fuchs E. Abstract 881: Dissecting chromatin dynamics in malignant progression. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Tumor-initiating cells within a cancer exhibit distinct patterns of transcription factors and gene expression compared to stem cells within their healthy tissue. Little is known about the key transcription factors that dictate chromatin remodeling and the accompanying transcriptional changes that ultimately hardwire the malignant behavior of tumor-initiating stem cells. Here, by in vivo chromatin and transcription profiling, we show that dramatic shifts in large open-chromatin (super-enhancer) landscapes underlie these differences. Focusing on one of the most common and life-threatening cancers world-wide, squamous cell carcinoma (SCC), we show that super-enhancers of SCC-stem cells contain the binding sites for a distinct set of putative master transcription factors. Many of their genes, including Ets2 and Elk3, are themselves regulated by SCC super-enhancers, suggesting a cooperative feed-forward loop. Malignant progression requires these genes, whose knockdown severely impairs tumor growth and prohibits progression from benign papillomas to SCCs. Interestingly, ETS2 is known to be phosphorylated and activated by RAS/MAPK signaling, and knockdown of ETS2 results in loss of expression of SCC super-enhancer-associated genes. Conversely, in vivo forced expression of an active ETS2 version harboring a phosphomimetic substitution at the MAPK-activation residue is sufficient to trigger cellular transformation without oncogenic RAS. Moreover, ETS2-overactivation in epidermal progenitors rewires the super-enhancer landscape and induces SCC super-enhancer associated genes including Fos, Junb, Klf5 and Elk3. Finally, we identify dramatic remodeling of the Cxcl1/2 locus from an H3K27me3-repressed to an ETS-regulated, super-enhancer-activated state, and provide evidence for their autocrine oncogenic role in SCCs through a cognate receptor Cxcr2. Together, our findings unearth an essential regulatory network required for the SCC chromatin landscape and unveil its importance in malignant progression.
This work was funded by grants from the National Institutes of Health (R01-AR31737) and NYSTEM #CO29559.
Citation Format: Hanseul Yang, Daniel Schramek, Rene Adam, John Levorse, Brice Keyes, Ping Wang, Deyou Zheng, Elaine Fuchs. Dissecting chromatin dynamics in malignant progression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 881.
Collapse
Affiliation(s)
| | - Daniel Schramek
- 2The Lunenfeld-Tanenbaum Research Institute, Toronto, Ontario, Canada
| | - Rene Adam
- 1The Rockefeller University, New York, NY
| | | | | | - Ping Wang
- 3Albert Einstein College of Medicine, New York, NY
| | - Deyou Zheng
- 3Albert Einstein College of Medicine, New York, NY
| | | |
Collapse
|
14
|
Metzger JM, Tadin-Strapps M, Thankappan A, Strapps WR, DiPietro M, Leander K, Zhang Z, Shin MK, Levorse J, Desai K, Xu Y, Lai K, Wu W, Chen Z, Cai TQ, Jochnowitz N, Bentley R, Hoos L, Zhou Y, Sepp-Lorenzino L, Seiffert D, Andre P. Titrating haemophilia B phenotypes using siRNA strategy: evidence that antithrombotic activity is separated from bleeding liability. Thromb Haemost 2015; 113:1300-11. [PMID: 25790442 DOI: 10.1160/th14-06-0505] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 01/20/2015] [Indexed: 11/05/2022]
Abstract
Haemophilia A and B are characterised by a life-long bleeding predisposition, and several lines of evidence suggest that risks of atherothrombotic events may also be reduced. Establishing a direct correlation between coagulation factor levels, thrombotic risks and bleeding propensity has long been hampered by an inability to selectively and specifically inhibit coagulation factor levels. Here, the exquisite selectivity of gene silencing combined with a gene knockout (KO) approach was used to define the relative contribution of factor IX (fIX) to thrombosis and primary haemostasis in the rat. Using a lipid nanoparticle (LNP) formulation, we successfully delivered fIX siRNAs to the liver by intravenous administration. The knockdown (KD) of target gene mRNA was achieved rapidly (within 24 hour post-siRNA dosing), sustained (maintained for at least 7 days post dosing) and not associated with changes in mRNA expression levels of other coagulation factors. We found that intermediate levels of liver fIX mRNA silencing (60-95 %) translating into a 50-99 % reduction of plasma fIX activity provided protection from thrombosis without prolonging the cuticle bleeding time. Over 99 % inhibition of fIX activity was required to observe increase in bleeding, a phenotype confirmed in fIX KO rats. These data provide substantial evidence of a participation of fIX in the mechanisms regulating thrombosis prior to those regulating primary haemostasis, therefore highlighting the potential of fIX as a therapeutic target. In addition, hepatic mRNA silencing using LNP-encapsulated siRNAs may represent a promising novel approach for the chronic treatment and prevention of coagulation-dependent thrombotic disorders in humans.
Collapse
Affiliation(s)
| | - Marija Tadin-Strapps
- Marija Tadin-Strapps, Department of Genetics and Pharmacogenomics, Merck Research Laboratories, Merck & Co., Inc., 33 Avenue E Louis Pasteur, Boston, MA 02115, USA, Tel.:+1 617 992 2339, E-mail:
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Patrick Andre
- Patrick Andre, Cardiometabolic Disease, Merck & Co., Inc., Galloping Hill Road, Kenilworth, NJ 07033, USA, Tel.:+1 908 740 7329, E-mail:
| |
Collapse
|
15
|
Chu X, Zhang Z, Yabut J, Horwitz S, Levorse J, Li XQ, Zhu L, Lederman H, Ortiga R, Strauss J, Li X, Owens KA, Dragovic J, Vogt T, Evers R, Shin MK. Characterization of multidrug resistance 1a/P-glycoprotein knockout rats generated by zinc finger nucleases. Mol Pharmacol 2011; 81:220-7. [PMID: 22049154 DOI: 10.1124/mol.111.074179] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The development of zinc finger nuclease (ZFN) technology has enabled the genetic engineering of the rat genome. The ability to manipulate the rat genome has great promise to augment the utility of rats for biological and pharmacological studies. A Wistar Hannover rat model lacking the multidrug resistance protein Mdr1a P-glycoprotein (P-gp) was generated using a rat Mdr1a-specific ZFN. Mdr1a was completely absent in tissues, including brain and small intestine, of the knockout rat. Pharmacokinetic studies with the Mdr1a P-gp substrates loperamide, indinavir, and talinolol indicated that Mdr1a was functionally inactive in the blood-brain barrier and intestine in Mdr1a(-/-) rats. To identify possible compensatory mechanisms in Mdr1a(-/-) rats, the expression levels of drug-metabolizing enzyme and transporter-related genes were compared in brain, liver, kidney, and intestine of male and female Mdr1a(-/-) and control rats. In general, alterations in gene expression of these genes in Mdr1a(-/-) rats seemed to be modest, with more changes in female than in male rats. Taken together, our studies demonstrate that the ZFN-generated Mdr1a(-/-) rat will be a valuable tool for central nervous system drug target validation and determining the role of P-gp in drug absorption and disposition.
Collapse
Affiliation(s)
- Xiaoyan Chu
- Pharmacokinetics, Pharmacodynamics and Drug Metabolism, Merck & Co. & Inc., Rahway, New Jersey 07065, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Ivanova N, Dobrin R, Lu R, Kotenko I, Levorse J, DeCoste C, Schafer X, Lun Y, Lemischka IR. Dissecting self-renewal in stem cells with RNA interference. Nature 2006; 442:533-8. [PMID: 16767105 DOI: 10.1038/nature04915] [Citation(s) in RCA: 747] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Accepted: 05/16/2006] [Indexed: 12/12/2022]
Abstract
We present an integrated approach to identify genetic mechanisms that control self-renewal in mouse embryonic stem cells. We use short hairpin RNA (shRNA) loss-of-function techniques to downregulate a set of gene products whose expression patterns suggest self-renewal regulatory functions. We focus on transcriptional regulators and identify seven genes for which shRNA-mediated depletion negatively affects self-renewal, including four genes with previously unrecognized roles in self-renewal. Perturbations of these gene products are combined with dynamic, global analyses of gene expression. Our studies suggest specific biological roles for these molecules and reveal the complexity of cell fate regulation in embryonic stem cells.
Collapse
Affiliation(s)
- Natalia Ivanova
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Semenova E, Wang X, Jablonski MM, Levorse J, Tilghman SM. An engineered 800 kilobase deletion of Uchl3 and Lmo7 on mouse chromosome 14 causes defects in viability, postnatal growth and degeneration of muscle and retina. Hum Mol Genet 2003; 12:1301-12. [PMID: 12761045 DOI: 10.1093/hmg/ddg140] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The Acrg minimal region is a 1.5-1.7 Mb domain defined by genetic complementation among deletions generated around Ednrb on chromosome 14 in mice. Mice homozygous for one of the deletions, Ednrb(s-1Acrg), exhibit embryonic lethality with defects associated with mesoderm development. We predicted that the region contains a single cluster of four genes that encode a TBC domain-containing protein (KIAA0603), a novel protein AK000009, the ubiquitin C-terminal hydrolase L3 (UCHL3) and an F-box/PDZ/LIM domain protein LMO7. A targeted internal deletion of Uchl3 (Uchl3(Delta3-7)) produced viable mice, eliminating this gene as a candidate for the embryonic lethality. To dissect the Acrg minimal region further, we utilized Cre-loxP-mediated chromosome engineering to generate a targeted 800 kb deletion (Lmo7(Delta800)) that removes the distal portion of the region. The deletion includes Uchl3, Lmo7 and an additional 500 kb downstream of the 3' end of Lmo7 where no genes are thought to reside. We found that approximately 40% of mice homozygous for this deletion die between birth and weaning, and are severely runted. The remaining homozygotes are viable, thus ruling out Lmo7 as a single gene candidate for the Ednrb(s-1Acrg) embryonic lethality. Both Uchl3(Delta3-7) and Lmo7(Delta800) mutants displayed retinal degeneration, muscular degeneration and growth retardation, but the severity of the muscular degeneration and growth retardation were enhanced in Lmo7(Delta800) homozygotes. We suggest that the increase in severity may reflect an interaction between Uchl3 and Lmo7 in the ubiquitin-mediated protein degradation pathway.
Collapse
Affiliation(s)
- Ekaterina Semenova
- Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | | | | | | | | |
Collapse
|
18
|
Abstract
Genomic imprinting, the differential expression of autosomal genes based on their parent of origin, is observed in all eutherian mammals that have been examined. In most instances the genes that are imprinted in one species are imprinted in others as well, suggesting that imprinting predated eutherian radiation. For example, the RNA-coding H19 gene is repressed upon paternal inheritance in all species examined to date. Thus, it is surprising that there is remarkably little sequence conservation among the cis-acting DNA regulatory elements that are required for imprinting of H19 and the tightly linked Igf2 gene. The most conserved characteristic in the imprinting control region (ICR) is the presence of multiple binding sites for the zinc finger protein CTCF, raising the possibility that CTCF binding might be sufficient for the reciprocal imprinting of H19 and Igf2. To investigate whether a human H19 transgene, harboring seven CTCF sites, is correctly recognized and imprinted in the mouse, a 100 kb transgene containing the human H19 gene was introduced into the mouse germline. The human transgene was specifically methylated after passage through the male germline in a copy number-dependent manner, but the methylation was unstable, undergoing progressive loss during development. Consequently, the transgene was highly expressed upon both maternal and paternal inheritance. These results argue that the signals for both the acquisition and maintenance of methylation imprinting are diverging rapidly.
Collapse
Affiliation(s)
- Beverly K Jones
- Howard Hughes Medical Institute and Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | | | | |
Collapse
|
19
|
Cleary MA, van Raamsdonk CD, Levorse J, Zheng B, Bradley A, Tilghman SM. Disruption of an imprinted gene cluster by a targeted chromosomal translocation in mice. Nat Genet 2001; 29:78-82. [PMID: 11528397 DOI: 10.1038/ng715] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Genomic imprinting is an epigenetic process in which the activity of a gene is determined by its parent of origin. Mechanisms governing genomic imprinting are just beginning to be understood. However, the tendency of imprinted genes to exist in chromosomal clusters suggests a sharing of regulatory elements. To better understand imprinted gene clustering, we disrupted a cluster of imprinted genes on mouse distal chromosome 7 using the Cre/loxP recombination system. In mice carrying a site-specific translocation separating Cdkn1c and Kcnq1, imprinting of the genes retained on chromosome 7, including Kcnq1, Kcnq1ot1, Ascl2, H19 and Igf2, is unaffected, demonstrating that these genes are not regulated by elements near or telomeric to Cdkn1c. In contrast, expression and imprinting of the translocated Cdkn1c, Slc22a1l and Tssc3 on chromosome 11 are affected, consistent with the hypothesis that elements regulating both expression and imprinting of these genes lie within or proximal to Kcnq1. These data support the proposal that chromosomal abnormalities, including translocations, within KCNQ1 that are associated with the human disease Beckwith-Wiedemann syndrome (BWS) may disrupt CDKN1C expression. These results underscore the importance of gene clustering for the proper regulation of imprinted genes.
Collapse
Affiliation(s)
- M A Cleary
- Howard Hughes Medical Institute and Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | | | | | | | | | | |
Collapse
|
20
|
Jones BK, Levorse J, Tilghman SM. Deletion of a nuclease-sensitive region between the Igf2 and H19 genes leads to Igf2 misregulation and increased adiposity. Hum Mol Genet 2001; 10:807-14. [PMID: 11285246 DOI: 10.1093/hmg/10.8.807] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The insulin-like growth factor 2 gene (Igf2) is imprinted in most somatic tissues of the mouse with the exception of the choroid plexus and leptomeninges of the brain, where it is expressed from both alleles. The imprinting of Igf2 is dependent upon an imprinting control region (ICR) that lies 90 kb 3' of the gene and acts as a chromatin insulator to block enhancers that lie further 3' on the chromosome. Based on this model we would expect that enhancers of brain-specific expression of Igf2 would lie 5' of the ICR, and thus be insensitive to its action. Here we describe a 12 kb deletion of a region 5' of the ICR that is hypersensitive to nuclease digestion in chromatin. Its deletion results in a biallelic decrease in expression of Igf2, but not H19, in the brain, consistent with the proposal that it encodes a positive regulatory element. In addition, the deletion results in a minor relaxation of Igf2 imprinting in skeletal muscle and tongue. Lastly, the reduction in IGFII expression in the adult is accompanied by increased fat deposition and occasional obesity. Overweight animals are hypophagic, suggesting that IGFII affects fat metabolism rather than feeding behavior in adult mice.
Collapse
Affiliation(s)
- B K Jones
- Howard Hughes Medical Institute and Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | | | | |
Collapse
|