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Nathans JF, Ayers JL, Shendure J, Simpson CL. Genetic Tools for Cell Lineage Tracing and Profiling Developmental Trajectories in the Skin. J Invest Dermatol 2024; 144:936-949. [PMID: 38643988 PMCID: PMC11034889 DOI: 10.1016/j.jid.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/28/2024] [Accepted: 02/08/2024] [Indexed: 04/23/2024]
Abstract
The epidermis is the body's first line of protection against dehydration and pathogens, continually regenerating the outermost protective skin layers throughout life. During both embryonic development and wound healing, epidermal stem and progenitor cells must respond to external stimuli and insults to build, maintain, and repair the cutaneous barrier. Recent advances in CRISPR-based methods for cell lineage tracing have remarkably expanded the potential for experiments that track stem and progenitor cell proliferation and differentiation over the course of tissue and even organismal development. Additional tools for DNA-based recording of cellular signaling cues promise to deepen our understanding of the mechanisms driving normal skin morphogenesis and response to stressors as well as the dysregulation of cell proliferation and differentiation in skin diseases and cancer. In this review, we highlight cutting-edge methods for cell lineage tracing, including in organoids and model organisms, and explore how cutaneous biology researchers might leverage these techniques to elucidate the developmental programs that support the regenerative capacity and plasticity of the skin.
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Affiliation(s)
- Jenny F Nathans
- Medical Scientist Training Program, University of Washington, Seattle, Washington, USA; Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Jessica L Ayers
- Molecular Medicine and Mechanisms of Disease PhD Program, Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA; Department of Dermatology, University of Washington, Seattle, Washington, USA
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA; Institute for Stem Cell & Regenerative Medicine, University of Washington, Seattle, Washington, USA
| | - Cory L Simpson
- Department of Dermatology, University of Washington, Seattle, Washington, USA; Institute for Stem Cell & Regenerative Medicine, University of Washington, Seattle, Washington, USA.
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Yokouchi M, Atsugi T, Logtestijn MV, Tanaka RJ, Kajimura M, Suematsu M, Furuse M, Amagai M, Kubo A. Epidermal cell turnover across tight junctions based on Kelvin's tetrakaidecahedron cell shape. eLife 2016; 5:19593. [PMID: 27894419 PMCID: PMC5127639 DOI: 10.7554/elife.19593] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 11/01/2016] [Indexed: 12/17/2022] Open
Abstract
In multicellular organisms, cells adopt various shapes, from flattened sheets of endothelium to dendritic neurons, that allow the cells to function effectively. Here, we elucidated the unique shape of cells in the cornified stratified epithelia of the mammalian epidermis that allows them to achieve homeostasis of the tight junction (TJ) barrier. Using intimate in vivo 3D imaging, we found that the basic shape of TJ-bearing cells is a flattened Kelvin's tetrakaidecahedron (f-TKD), an optimal shape for filling space. In vivo live imaging further elucidated the dynamic replacement of TJs on the edges of f-TKD cells that enables the TJ-bearing cells to translocate across the TJ barrier. We propose a spatiotemporal orchestration model of f-TKD cell turnover, where in the classic context of 'form follows function', cell shape provides a fundamental basis for the barrier homeostasis and physical strength of cornified stratified epithelia. DOI:http://dx.doi.org/10.7554/eLife.19593.001 The skin surface – known as the epidermis – is made up of sheets of cells that are stacked up in layers. One of the roles of the skin is to provide a protective barrier that limits what leaks into or out of the body. A particular layer of the epidermis – referred to as the stratum granulosum – is primarily responsible for forming this barrier. The cells in this layer are sealed together in a zipper-like fashion by structures known as tight junctions. New skin cells are continuously produced in the lowest cell layers of the epidermis, and move upwards to integrate into the stratum granulosum layer to replace old cells (which also move upwards to leave the layer). How stratum granulosum cells are replaced without disrupting the tight junction barrier was not well understood. Yokouchi et al. used a technique called confocal microscopy to examine the stratum granulosum cells in the ears of mice, and found that the shape of these cells forms the basis of the barrier that they form. These cells resemble a flattened version of a shape called Kelvin’s tetrakaidecahedron: a 14-sided solid with six rectangular and eight hexagonal sides. This structure was proposed by Lord Kelvin in 1887 to be the best shape for filling space. Tight junctions are present on the edges of the flattened Kelvin’s tetrakaidecahedron. Further experiments revealed that the tight junctions move from cell to cell in a spatiotemporally-coordinated manner in order to maintain a continuous barrier throughout the stratum granulosum as cells are replaced. A newly formed stratum granulosum cell appears beneath the cell that it will replace. The shape of these cells enables a new barrier of three-way tight junction contacts to form between them and the neighboring cells in the stratum granulosum. After this barrier has formed, the upper cell leaves the stratum granulosum. Future research could address how cells adopt the flattened Kelvin’s tetrakaidecahedron shape, and discover why tight junctions only form in one layer of the epidermis. DOI:http://dx.doi.org/10.7554/eLife.19593.002
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Affiliation(s)
- Mariko Yokouchi
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.,Nerima General Hospital, Tokyo, Japan
| | - Toru Atsugi
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.,KOSÉ Corporation, Tokyo, Japan
| | - Mark van Logtestijn
- Department of Bioengineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Reiko J Tanaka
- Department of Bioengineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Mayumi Kajimura
- Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan.,Suematsu Gas Biology Project, Exploratory Research for Advanced Technology, Japan Science and Technology, Tokyo, Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan.,Suematsu Gas Biology Project, Exploratory Research for Advanced Technology, Japan Science and Technology, Tokyo, Japan
| | - Mikio Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Masayuki Amagai
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.,RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Akiharu Kubo
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
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Niwa O, Barcellos-Hoff MH, Globus RK, Harrison JD, Hendry JH, Jacob P, Martin MT, Seed TM, Shay JW, Story MD, Suzuki K, Yamashita S. ICRP Publication 131: Stem Cell Biology with Respect to Carcinogenesis Aspects of Radiological Protection. Ann ICRP 2016; 44:7-357. [PMID: 26637346 DOI: 10.1177/0146645315595585] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This report provides a review of stem cells/progenitor cells and their responses to ionising radiation in relation to issues relevant to stochastic effects of radiation that form a major part of the International Commission on Radiological Protection's system of radiological protection. Current information on stem cell characteristics, maintenance and renewal, evolution with age, location in stem cell 'niches', and radiosensitivity to acute and protracted exposures is presented in a series of substantial reviews as annexes concerning haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin, and bone. This foundation of knowledge of stem cells is used in the main text of the report to provide a biological insight into issues such as the linear-no-threshold (LNT) model, cancer risk among tissues, dose-rate effects, and changes in the risk of radiation carcinogenesis by age at exposure and attained age. Knowledge of the biology and associated radiation biology of stem cells and progenitor cells is more developed in tissues that renew fairly rapidly, such as haematopoietic tissue, intestinal mucosa, and epidermis, although all the tissues considered here possess stem cell populations. Important features of stem cell maintenance, renewal, and response are the microenvironmental signals operating in the niche residence, for which a well-defined spatial location has been identified in some tissues. The identity of the target cell for carcinogenesis continues to point to the more primitive stem cell population that is mostly quiescent, and hence able to accumulate the protracted sequence of mutations necessary to result in malignancy. In addition, there is some potential for daughter progenitor cells to be target cells in particular cases, such as in haematopoietic tissue and in skin. Several biological processes could contribute to protecting stem cells from mutation accumulation: (a) accurate DNA repair; (b) rapidly induced death of injured stem cells; (c) retention of the DNA parental template strand during divisions in some tissue systems, so that mutations are passed to the daughter differentiating cells and not retained in the parental cell; and (d) stem cell competition, whereby undamaged stem cells outcompete damaged stem cells for residence in the niche. DNA repair mainly occurs within a few days of irradiation, while stem cell competition requires weeks or many months depending on the tissue type. The aforementioned processes may contribute to the differences in carcinogenic radiation risk values between tissues, and may help to explain why a rapidly replicating tissue such as small intestine is less prone to such risk. The processes also provide a mechanistic insight relevant to the LNT model, and the relative and absolute risk models. The radiobiological knowledge also provides a scientific insight into discussions of the dose and dose-rate effectiveness factor currently used in radiological protection guidelines. In addition, the biological information contributes potential reasons for the age-dependent sensitivity to radiation carcinogenesis, including the effects of in-utero exposure.
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Martin MT, Vulin A, Hendry JH. Human epidermal stem cells: Role in adverse skin reactions and carcinogenesis from radiation. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2016; 770:349-368. [PMID: 27919341 DOI: 10.1016/j.mrrev.2016.08.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/12/2016] [Accepted: 08/13/2016] [Indexed: 02/06/2023]
Abstract
In human skin, keratinopoiesis is based on a functional hierarchy among keratinocytes, with rare slow-cycling stem cells responsible for the long-term maintenance of the tissue through their self-renewal potential, and more differentiated daughter progenitor cells actively cycling to permit epidermal renewal and turn-over every month. Skin is a radio-responsive tissue, developing all types of radiation damage and pathologies, including early tissue reactions such as dysplasia and denudation in epidermis, and later fibrosis in the dermis and acanthosis in epidermis, with the TGF-beta 1 pathway as a known master switch. Also there is a risk of basal cell carcinoma, which arises from epidermal keratinocytes, notably after oncogenic events in PTCH1 or TP53 genes. This review will cover the mechanisms of adverse human skin reactions and carcinogenesis after various types of exposures to ionizing radiation, with comparison with animal data when necessary, and will discuss the possible role of stem cells and their progeny in the development of these disorders. The main endpoints presented are basal cell intrinsic radiosensitivity, genomic stability, individual factors of risk, dose specific responses, major molecular pathways involved and the cellular origin of skin reactions and cancer. Although major advances have been obtained in recent years, the precise implications of epidermal stem cells and their progeny in these processes are not yet fully characterized.
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Affiliation(s)
- Michèle T Martin
- CEA/DRF/IRCM/LGRK, 91057 Evry, France; INSERM U967, 92265 Fontenay aux Roses, Cedex, France; Université Paris-Diderot, Paris 7, France; Université Paris-Saclay, Paris 11, France.
| | - Adeline Vulin
- CEA/DRF/IRCM/LGRK, 91057 Evry, France; INSERM U967, 92265 Fontenay aux Roses, Cedex, France; Université Paris-Diderot, Paris 7, France; Université Paris-Saclay, Paris 11, France
| | - Jolyon H Hendry
- Christie Medical Physics and Engineering, Christie Hospital and University of Manchester, Manchester, United Kingdom
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Aktipis CA, Boddy AM, Jansen G, Hibner U, Hochberg ME, Maley CC, Wilkinson GS. Cancer across the tree of life: cooperation and cheating in multicellularity. Philos Trans R Soc Lond B Biol Sci 2015; 370:20140219. [PMID: 26056363 PMCID: PMC4581024 DOI: 10.1098/rstb.2014.0219] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2015] [Indexed: 02/06/2023] Open
Abstract
Multicellularity is characterized by cooperation among cells for the development, maintenance and reproduction of the multicellular organism. Cancer can be viewed as cheating within this cooperative multicellular system. Complex multicellularity, and the cooperation underlying it, has evolved independently multiple times. We review the existing literature on cancer and cancer-like phenomena across life, not only focusing on complex multicellularity but also reviewing cancer-like phenomena across the tree of life more broadly. We find that cancer is characterized by a breakdown of the central features of cooperation that characterize multicellularity, including cheating in proliferation inhibition, cell death, division of labour, resource allocation and extracellular environment maintenance (which we term the five foundations of multicellularity). Cheating on division of labour, exhibited by a lack of differentiation and disorganized cell masses, has been observed in all forms of multicellularity. This suggests that deregulation of differentiation is a fundamental and universal aspect of carcinogenesis that may be underappreciated in cancer biology. Understanding cancer as a breakdown of multicellular cooperation provides novel insights into cancer hallmarks and suggests a set of assays and biomarkers that can be applied across species and characterize the fundamental requirements for generating a cancer.
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Affiliation(s)
- C Athena Aktipis
- Center for Evolution and Cancer, University of California San Francisco, San Francisco, CA 94143, USA Department of Psychology, Arizona State University, Tempe, AZ 85287-4501, USA Centre for Evolution and Cancer, Institute for Cancer Research, 123 Old Brompton Road, London SW7 3RP, UK Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Amy M Boddy
- Center for Evolution and Cancer, University of California San Francisco, San Francisco, CA 94143, USA Department of Psychology, Arizona State University, Tempe, AZ 85287-4501, USA Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Gunther Jansen
- Department of Evolutionary Ecology and Genetics, University of Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Urszula Hibner
- CNRS, UMR 5535, Institut de Génétique Moléculaire de Montpellier, Université de Montpellier, Montpellier, France Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Michael E Hochberg
- Institut des Sciences de l'Evolution, CNRS UMR5554, Université Montpellier, 34095 Montpellier, France Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Carlo C Maley
- Center for Evolution and Cancer, University of California San Francisco, San Francisco, CA 94143, USA Centre for Evolution and Cancer, Institute for Cancer Research, 123 Old Brompton Road, London SW7 3RP, UK Biodesign Institute, School of Life Sciences, Arizona State University, PO Box 8724501, Tempe, AZ 85287-4501, USA Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
| | - Gerald S Wilkinson
- Department of Biology, University of Maryland, College Park, MD 20742, USA Institute for Advanced Study, Wissenschaftskolleg zu Berlin, Berlin, Germany
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Leydon C, Bartlett RS, Roenneburg DA, Thibeault SL. Localization of label-retaining cells in murine vocal fold epithelium. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2011; 54:1060-6. [PMID: 21330647 PMCID: PMC3167580 DOI: 10.1044/1092-4388(2010/10-0267)] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
PURPOSE Epithelial homeostasis is critical for vocal fold health, yet little is known about the cells that support epithelial self-renewal. As a known characteristic of stem cells is that they are slow-cycling in vivo, the purpose of this prospective controlled study was to identify and quantify slow-cycling cells or putative stem cells in murine vocal fold epithelium. METHOD Twelve mice were administered daily intraperitoneal injections of a nucleotide dye, bromodeoxyuridine (BrdU), over 7 consecutive days. Under this pulse-chase paradigm, slow-cycling cells retain the dye (label-retaining cells; LRCs) while more rapidly cycling cells lose dye to dilution during multiple cell divisions. The percentage of label-retaining cells (%LRCs) was calculated following a chase period of 2, 4, and 8 weeks postinjections. RESULTS The %LRCs decreased significantly from 9.4% at 2 weeks to 3.1% at 8 weeks following injections (p < .05). No statistically significant differences in the quantity of BrdU-positive cells were measured between the anterior, mid-membranous, or cartilaginous regions of the vocal fold (p > .05). CONCLUSION These findings are consistent with the presence and first report of a small population of putative stem cells along the length of murine vocal fold epithelium.
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7
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Oakley B. Neuronal-epithelial interactions in mammalian gustatory epithelium. CIBA FOUNDATION SYMPOSIUM 2007; 160:277-87; discussion 287-93. [PMID: 1752168 DOI: 10.1002/9780470514122.ch14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
There are two neurally controlled morphogenetic programmes in the fungiform papillae of the rodent tongue. When gustatory axons are present they not only promote the expression of taste receptor cells but also simultaneously suppress the outgrowth of an ectopic filiform spine. Innervation during development is essential for the initial formation of taste buds. Consequently, denervation during development irreversibly prevents the establishment of a permanent line of stem cells for taste buds, in contrast to the reliable re-emergence of taste buds after the reinnervation of denervated adult gustatory epithelium. Monoclonal antibodies to keratins selectively recognize cells in particular differentiated states and may contribute to an understanding of the cell lineages and cell-cell interactions that lead to taste buds and filiform spines. Regeneration may recapitulate the late steps in taste development but not the early steps, which are slower and subject to irreversible alteration with denervation. Arguments are set forth that the nerve dependence of taste buds and some other cutaneous receptor cells provides an important selective advantage. Nerve dependence ensures that a more protective integumental covering will replace any superficial, secondary sensory cells rendered useless by denervation.
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Affiliation(s)
- B Oakley
- Department of Biology, University of Michigan, Ann Arbor 48109
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8
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Potten CS. Keratinocyte stem cells, label-retaining cells and possible genome protection mechanisms. J Investig Dermatol Symp Proc 2004; 9:183-95. [PMID: 15369212 DOI: 10.1111/j.1087-0024.2004.09305.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Stem cells are the crucial cells upon which the entire tissue is dependent. Here we define and discuss what is meant by and known about keratinocyte stem cells. One way in which these cells have been studied is by their ability to retain radioactivity labelled thymidine for long periods of time (label retaining cells, LRCs). The underlying mechanism has been assumed in the past to be slow cycling but a more likely explanation is the selective segregation of old and new DNA strands (Cairns's hypothesis). Experiments in the small intestine indicate that the stem cells here are selectively sorting their DNA and becoming LRCs. A possible role for p53 in stem cell biology is presented.
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9
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Wilson RP, McLaughlin PJ, Lang CM, Zagon IS. The opioid growth factor, [Met5]-enkephalin, inhibits DNA synthesis during recornification of mouse tail skin. Cell Prolif 2000; 33:63-73. [PMID: 10845251 PMCID: PMC6496561 DOI: 10.1046/j.1365-2184.2000.00161.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Opioid peptides serve as tonically active negative growth regulators in renewing and regenerating epithelia. To examine the involvement of opioids in renewal of the stratum corneum after tape stripping of tail skin, C57BL/6 J mice were given systemic injections of the potent opioid antagonist, naltrexone (NTX, 20 mg/kg i.p.) following injury. Blockade of opioid-receptor interaction by NTX for 4 h resulted in an elevation of 36-66% in basal cell DNA synthesis measured 24 h after injury. Injection of the endogenous opioid peptide, [Met5]-enkephalin (OGF, 10 mg/kg i.p.) 4 h before termination, suppressed radiolabelled thymidine incorporation in the basal cell layer by 37-46% at 24 h after wounding. The magnitude of the effects on DNA synthesis of OGF, but not NTX, depended on the timing of administration with respect to injury. OGF maximally depressed basal cell labelling (72%) when given 16 h after tape stripping. Concomitant administration of naloxone (10 mg/kg) with OGF blocked the inhibition of DNA synthesis; naloxone alone at the dosage utilized had no effect on cell labelling. Both OGF and its receptor, OGFr, were detected by immunocytochemistry in the basal and suprabasal cell layers, but not the cornified layer of tape stripped and uninjured tail skin. These results indicate: (a) a native opioid peptide and its receptor are expressed in epidermal cells of injured and uninjured mouse tail skin; (b) removal of the stratum corneum by tape stripping does not disrupt the function of the endogenous opioid growth system; (c) the proliferative response to wounding of the tail is tonically inhibited by the receptor-mediated action of an endogenous opioid peptide; and (d) DNA synthesis by basal cells can be elevated by disrupting opioid peptide receptor interactions.
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Affiliation(s)
- R P Wilson
- Department of Comparative Medicine, College of Medicine, The Pennsylvania State University, Hershey 17033-2390, USA.
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10
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Rizvi AZ, Wong MH. Nuclear localization of beta-catenin by interaction with transcription factor LEF-1. Stem Cells 1997; 23:150-65. [PMID: 15671140 DOI: 10.1634/stemcells.2004-0096] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Vertebrate beta-catenin and Drosophila Armadillo share structural similarities suggesting that beta-catenin, like Armadillo, has a developmental signaling function. Both proteins are present as components of cell adherens junctions, but accumulate in the cytoplasm upon Wingless/Wnt signaling. beta-Catenin has axis-inducing properties like Wnt when injected into Xenopus blastomeres, providing evidence for participation of beta-catenin in the Wnt-pathway, but until now no downstream targets for beta-catenin have been identified. Here we demonstrate that beta-catenin binds to the HMG-type transcription factor lymphoid enhancer factor-1 (LEF-1), resulting in a nuclear translocation of beta-catenin both in cultured mouse cells and after ectopic expression of LEF-1 in two-cell mouse embryos. LEF-1/beta-catenin complexes bind to the promoter region of the E-cadherin gene in vitro, suggesting that this interaction could regulate E-cadherin transcription. As shown for beta-catenin, ectopic expression of LEF-1 in Xenopus embryos caused duplication of the body axis, indicating a regulatory role for a LEF-1-like molecule in dorsal mesoderm formation.
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Affiliation(s)
- Adnan Z Rizvi
- Department of Surgery, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, Oregon 97239, USA
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11
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Honda H, Tanemura M, Imayama S. Spontaneous architectural organization of mammalian epidermis from random cell packing. J Invest Dermatol 1996; 106:312-5. [PMID: 8601733 DOI: 10.1111/1523-1747.ep12342964] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The cells of the stratum corneum in the epidermis of some mammalian species are precisely stacked in columns in a honeycomb fashion. The epidermis constantly loses surface cells, which are replaced by basal cells that have differentiated during migration to the surface. The path of this migration is seen as precisely defined columns of cells that are in compressed Kelvin's tetrakaidecahedral form. We present a computer simulation of this architectural organization based on the assumption that the cells that migrate upward occupy less crowded regions. The simulation not only explained the mechanism by which the architecture is maintained during the process of cell replacement, but also showed that the architecture was spontaneously organized from initial cells supplied at random. Living organisms consist of self-organizing systems at various levels; however, self-organizing systems have been investigated mostly at the molecular level. The present computer simulation clarified the self-organizing system at the cellular level.
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Affiliation(s)
- H Honda
- Kanebo Institute for Cancer Research, Tomobuchicho, Miyakojimaku, Osaka, Japan
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12
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Parkinson EK. Epidermal keratinocyte stem cells: their maintenance and regulation. SEMINARS IN CELL BIOLOGY 1992; 3:435-44. [PMID: 1489975 DOI: 10.1016/1043-4682(92)90014-m] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The epidermis is a stratified epithelium consisting of interfollicular regions and appendages (hair follicles, sweat glands, sebaceous glands). The dominant cell type (the keratinocyte) is arranged in groups of cells termed epidermal proliferative units (EPUs), and one centrally-located clonogenic stem cell is ultimately responsible for replacing the remainder of the cells in the unit. Evidence is reviewed which indicates that the epidermal Langerhans' cell (ELC), and the cells comprising the dermis, may modify the keratinocyte microenvironment to create stem cell 'niches' and cellular diversity within the basal layer.
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Affiliation(s)
- E K Parkinson
- Beatson Institute for Cancer Research, Bearsden, Glasgow, UK
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13
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Abstract
The tongue surface directly above a fungiform taste bud is flat, thinly keratinized, and free of filiform spines. We examined fungiform papillae in serial sections of rat and gerbil tongues after unilateral transection of the chorda-lingual nerve had caused many fungiform taste buds to degenerate. Such empty fungiform papillae often formed a solitary keratinized outgrowth that closely resembled the spine of an ordinary filiform papilla. By six months an ectopic spine was found on 61% of empty fungiform papillae, but never on fungiform papillae that contained a taste bud. Experimental innervation of the tongue reduced the incidence of ectopic filiform spines in proportion to the cross-sectional area of the trigeminal nerve branches tested (the mylohyoid nerve, the lingual nerve, lingual + mylohyoid or lingual + auriculotemporal nerves). The chorda tympani nerve was 60 times more effective than trigeminal nerves in preventing ectopic filiform spines. We suggest that positive and negative trophic actions are normal characteristics of taste axons, for they promote the formation of taste buds and prevent the expression of ectopic filiform spines. By preventing the outgrowth of ectopic spines on fungiform papillae, taste axons maintain a thinly keratinized apical surface that can be breached by the taste receptor cells.
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Affiliation(s)
- B Oakley
- Department of Biology, University of Michigan, Ann Arbor 48109
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14
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Boyd NM, Reade PC. Differences between preneoplastic cells, neoplastic cells and their normal counterparts. JOURNAL OF ORAL PATHOLOGY 1988; 17:257-65. [PMID: 3144588 DOI: 10.1111/j.1600-0714.1988.tb01534.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A number of changes occur in preneoplastic and neoplastic cells as they progress towards a greater degree of malignancy. These alterations include genetic changes, epigenetic changes, surface alterations and alterations in intercellular interactions. In some instances, these changes are contributing factors to the degree of pathology noted, whilst other are resultant. In many situations, the relationship between these changes and the progression towards neoplasia is not understood. Nevertheless, it seems probable that these changes are ultimately involved in driving cells further along the path to neoplastic transformation. It is the purpose of this review to consider the changes which occur as cells progress from normality to being neoplastic, with particular reference to the cells of the oral mucosa, and the use to which detectable changes can be used as prognostic indicators.
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Affiliation(s)
- N M Boyd
- Department of Oral Biology, University of Otago, Dunedin, New Zealand
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15
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Honda H, Oshibe S. A computer simulation of cell stacking for even thickness in mammalian epidermis. J Theor Biol 1984; 111:625-33. [PMID: 6527547 DOI: 10.1016/s0022-5193(84)80258-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The method of even stacking of epidermal cells in mammalian skin was studied by computer simulation. The epidermis consists of neat vertical columns of stacked, flattened, tetrakaidecahedral cells. Cells which have been proliferated in a basal layer migrate upwards, occupy the bottom regions of vertical columns, and become members constituting columns. Computer simulations demonstrated that the column height becomes considerably varied if the cells are randomly supplied from the basal layer. In contrast, if the cells are assumed to have an ability to find the uppermost region among the column's bases consisting of one base where the cell has reached and its neighbouring bases, the cells stack into columns whose heights are remarkably uniform even if the cells are randomly supplied. The results indicated that an epidermal structure consisting of the flattened polyhedral cells could itself function as a control mechanism of the epidermal thickness.
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Bickenbach JR, Mackenzie IC. Identification and localization of label-retaining cells in hamster epithelia. J Invest Dermatol 1984; 82:618-22. [PMID: 6725984 DOI: 10.1111/1523-1747.ep12261460] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A subpopulation of basal epithelial cells which retains tritiated thymidine label for extended periods was previously demonstrated in skin and oral mucosae of mice. The present study examined the presence of similar cells in hamsters. Five-day-old hamsters were labeled with tritiated thymidine and the rate at which label was diluted from the basal cells observed. A small percentage of basal cells was found to retain label for up to 69 days. The location of such label-retaining cells ( LRCs ) in the palatal epithelium and in tongue papillae was examined. Thirty and 69 days after labeling, approximately 80% of LRCs in palate were located in the proximal halves of papillae and 80% of LRCs in tongue were positioned basally with approximately 30% of such LRCs occupying positions previously suggested to be stem cell locations. The finding that slowly cycling keratinocytes are related to patterns of tissue architecture is compatible with a function of these cells as epithelial stem cells.
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Abstract
Studies performed on mouse skin have indicated that chemical carcinogenesis can be subdivided into two distinct stages, initiation and promotion. Initiation results from exposure to a classical mutagenic carcinogen and is irreversible even after a single exposure. The permanently altered initiated cell and its progeny may never form a tumor or in any way be recognizable in the target tissue. Exposure to tumor promoters permits the expression of the neoplastic change in initiated cells, and tumors develop. In contrast to initiators, promoters must be given repeatedly to be effective; individual exposures are reversible. A similar biology is suggested by epidemiologic studies of certain human cancers, particularly lung, breast, colon, and uterine malignancies. Studies in mouse skin cell culture have provided new insights into the changes associated with initiation and promotion. Initiated cells appear to be resistant to signals for terminal differentiation and can proliferate under conditions where normal epidermal cells are obligated to cease proliferation and begin their maturation program. This change is essential for an epithelial tumor cell since it provides the ability to grow away from a basement-membrane attachment site. In cultured epidermal cells, tumor promoters are capable of selectively stimulating the growth of certain cells, including initiated cells, while simultaneously inducing terminal differentiation in other epidermal cells. The net effect of these responses to promoters is the clonal expansion of cells stimulated to proliferate. In this way, promoters are capable of increasing the clone size of initiated cells. These cell culture data provided a biological framework for understanding initiation and promotion in terminally differentiating epithelial tissues.
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Yuspa SH, Hennings H, Lichti U, Kulesz-Martin M. Organ specificity and tumor promotion. BASIC LIFE SCIENCES 1983; 24:157-71. [PMID: 6860263 DOI: 10.1007/978-1-4684-4400-1_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Yuspa SH, Hennings H, Lichti U. Initiator and promoter induced specific changes in epidermal function and biological potential. JOURNAL OF SUPRAMOLECULAR STRUCTURE AND CELLULAR BIOCHEMISTRY 1981; 17:245-57. [PMID: 7328673 DOI: 10.1002/jsscb.380170306] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Mouse epidermal basal cells can be selectively cultivated in medium with a calcium concentration of 0.01--9.09 mM. Terminal differentiation and sloughing of mature keratinocytes occur when the calcium concentration is increased to 1.2--1.4 mM. When basal cell cultures are exposed to chemical initiators of carcinogenesis, colonies of cells that resist calcium-induced differentiation evolve. Likewise, basal cells derived from mouse skin initiated in vivo yield foci that resist terminal differentiation. This defect in the commitment to terminal differentiation appears to be an essential change in initiated cells in skin and is also characteristic of malignant epidermal cells. This model system has also provided a means to determine if basal cells are more responsive to phorbol esters than other cells in epidermis and to explore the possibility that heterogeneity of response exists within subpopulations of basal cells. The induction of the enzyme ornithine decarboxylase (ODC) was used as a marker for responsiveness to phorbol esters. ODC induction after exposure to 12-0-tetradecanoylphorbol-13-acetate (TPA) in basal cells is enhanced 20-fold over the response of a culture population containing both differentiating and basal cells. When basal cells are induced to differentiate by increased calcium, responsiveness to TPA is lost within several hours. In basal cell cultures, two ODC responses can be distinguished. After exposure to low concentrations of TPA or to weak promoters of the phorbol ester series, ODC activity is maximal at 3 hr. With higher concentrations of TPA, the ODC maximum is at 9 hr. These results are consistent with the presence of subpopulations of basal cells with differing sensitivities to TPA. Other studies that use the enzyme epidermal transglutaminase as a marker for differentiation support this conclusion. In basal cell culture TPA exposure rapidly increases transglutaminase activity and cornified envelope development, reflecting induced differentiation in some cells. As differentiated cells are sloughed from the dish, the remaining basal cells proliferate and become resistant to induced differentiation by 1.2 mM calcium. These data provide additional evidence of basal cell heterogeneity in which TPA induces one subpopulation to differentiate while another is stimulated to proliferate and resists a differentiation signal. Tumor promoters, by their ability to produce heterogeneous responses with regard to terminal differentiation and proliferation, would cause redistribution of subpopulations of epidermal cells in skin. Cells that resist signals for terminal differentiation, such as initiated cells, would be expected to increase in number during remodeling, Clonal expansion of the initiated population could result in a benign tumor with an altered program of differentiation. In skin, benign tumors are the principal product of 2-stage carcinogenesis. Subsequent progression to malignancy may involve an additional step, probably a genetic alteration, that is independent of the tumor promoter.
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Potten CS. Cell replacement in epidermis (keratopoiesis) via discrete units of proliferation. INTERNATIONAL REVIEW OF CYTOLOGY 1981; 69:271-318. [PMID: 6163744 DOI: 10.1016/s0074-7696(08)62326-8] [Citation(s) in RCA: 227] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Honda H, Morita T, Tanabe A. Establishment of epidermal cell columns in mammalian skin: computer simulation. J Theor Biol 1979; 81:745-59. [PMID: 537395 DOI: 10.1016/0022-5193(79)90279-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Abstract
There is growing evidence that the basal layer of stratified squamous epithelia consists of cells of differing proliferative capacities and behaviour. These can be classified as stem cells, transient amplifying cells and post-mitotic maturing cells, the most important of which appear to be the stem cells which may be present throughout life and are responsible for all cell production under steady-state conditions. Recent stem cell concepts are reviewed for epidermis, intestinal crypt and oral mucosa and are compared with tissues such as bone marrow and testes which have for some time been thought to operate in a similar manner. These concepts are applied to several pathological conditions of oral epithelia in an attempt to explain some of the changes observed.
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Abstract
A new type of squame arrangements is described in guinea-pig ear epidermis. It is characterized by overlapping obliquely-angled outer cells and squames, which thus form a roof-tile pattern. This pattern develops in epidermis that is thicker than about 42 micron; in thinner epidermis the outer cells and squames form the usual columnar stacks. It is concluded that the roof-tile pattern, which is usually directed towards the ear edge, is typical of slight to moderate hyperplasia. In extreme hyperplasia, when the strata granulosum and corneum are destroyed, only cellular disorder is seen.
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Abstract
Standardized techniques of stereologic cytology were applied to normal human epidermis, in order to comparatively describe the suprabasal and the dark and clear basal keratinocytes. The results, expressed mainly in surface and volume densities of epidermal components, showed that some important stereologic parameters of dark basal keratinocyte constituents exhibited values which could be interpreted as intermediate between those of the clear basal keratinocytes and those of the suprabasal keratinocytes. Although the degenerative nature of dark cells cannot be ruled out, the stereologic characterization of their cell architecture also could indicate that dark basal cells are already differentiating keratinocytes still remaining in the basal layer.
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Abstract
Recent advances in the biology of mammalian pigmentation are reviewed. The multicellular epidermal melanin unit (melanocyte and associated pool of keratinocytes) rather than the melanocyte alone forms the focal point for melanin metabolism within mammalian epidermis. Within an epidermal melanin unit, melanosomes are synthesized by melanocytes and transferred to keratinocytes where they are degraded as they ascend to the epidermal surface. During the past 25 years, technical advances in biology and biochemistry have frosted a multidisciplinary approach to research on mammalian pigmentation. Emphasizing this perspective, we have examined the current state of knowledge of the form and function of epidermal melanin units from the levels of biologic organization ranging from the molecules relevant to melanin synthesis through the skin as a totally intergrated system. To an unusual degree, advances in melanin pigmentation have resulted from the integration of clinical medicine and basic science.
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Freeman AE, Igel HJ, Herrman BJ, Kleinfeld KL. Growth and characterization of human skin epithelial cell cultures. IN VITRO 1976; 12:352-62. [PMID: 780259 DOI: 10.1007/bf02796313] [Citation(s) in RCA: 113] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In 129 of 140 attempts, human skin cells were successfully cultured on the dermal collagen bed of sterile, dead pigskin. Diploid epithelial cells grew selectively on the collagen bed; fibroblasts grew on the glass surfaces of the culture dishes. The cultures could be subdivided physically up to six times at a 1:2 split ratio, but at least 24 to 48 cell generations were produced over the months the cells could be carried. Much of the cell multiplication resulted in maturation into distinct basal, squamous, granular, and keratinized cell layers. The cultured cells were considered epithelial because of their shape, possession of intercellular bridges, desmosomes and tonofibrils, and because they formed maturating epithelium in vitro and upon transplantation back to the original human donor. As the cells grew they digested the pigskin collagen, thus producing clear zones that could be used to monitor and quantitate cell growth. Multiplication of epilthelial cells, rather than migration, was indicated by mitotic figures in colchicine-treated cultures and by DNA synthesis.
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Abstract
A tentative model is presented which is based on existing data and our own cell kinetic and morphological observations in mice. The model suggests that the epidermal Langerhans cell plays a role in proliferation control of keratinocytes and may also act as an epidermal stem cell.
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Abstract
Labeling and mitotic index data and estimates for the length of the S and M phases of the cell cycle from the literature have been compared with new data obtained over a 24-hr period from various epidermal sites in mouse. It has been found that values obtained at a single time of the day may give misleading results. All data have been interpreted in terms of cell production rates per epidermal proliferative unit (EPU). The final conclusions after consideration of cell production rates, labeling and mitotic indices, epidermal transit times, and epidermal structure are that dorsal and ear skin have rather similar cell production rates while tail and foot rates are 4 to 7 times higher. A comparison has also been made between the mouse results and the available human data. Hairless mouse dorsum appears from structural and proliferative aspects to be the best model for some regions of human skin. A new model has been proposed for epidermal proliferation based on the EPU. The model suggests a role for the Langerhans cells and suggests that there is a program of sequential cellular maturity in the EPU originating at the level of a central basal stem cell through committed proliferative cells and ending with cell loss from the skin surface.
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