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Son JW, Shin JJ, Kim MG, Kim J, Son SW. Keratinocyte-specific knockout mice models via Cre–loxP recombination system. Mol Cell Toxicol 2021. [DOI: 10.1007/s13273-020-00115-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Huang S, Rompolas P. Two-photon microscopy for intracutaneous imaging of stem cell activity in mice. Exp Dermatol 2017; 26:379-383. [PMID: 27676122 PMCID: PMC7405986 DOI: 10.1111/exd.13221] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2016] [Indexed: 12/17/2022]
Abstract
The adult skin is a typical example of a highly regenerative tissue. Terminally differentiated keratinocytes are shed from the external layers of the epidermis or extruded from the skin as part of the growing hair shaft on a daily basis. These are effectively replenished through the activity of skin-resident stem cells. Precise regulation of stem cell activity is critical for normal skin homoeostasis or wound healing and irregular stem cell proliferation or differentiation can lead to skin disease. The scarcity and dynamic nature of stem cells presents a major challenge for elucidating their mechanism of action. To address this, we have recently established a system for visualizing stem cell activity, in real time or long term, in the intact skin of live mice using two-photon microscopy. The purpose of this review was to provide essential information to researchers who wish to incorporate two-photon microscopy and live imaging into their experimental toolbox for studying aspects of skin and stem biology in the mouse model. We discuss fundamental principles of the method, instrumentation and basic experimental approaches to interrogate stem cell activity in the interfollicular epidermis and hair follicle.
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Affiliation(s)
- Sixia Huang
- Department of Dermatology, Institute for Regenerative Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 U.S.A
| | - Panteleimon Rompolas
- Department of Dermatology, Institute for Regenerative Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 U.S.A
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Deken MA, Song JY, Gadiot J, Bins AD, Kroon P, Verbrugge I, Blank CU. Dermal Delivery of Constructs Encoding Cre Recombinase to Induce Skin Tumors in Pten LoxP/LoxP;Braf CA/+ Mice. Int J Mol Sci 2016; 17:ijms17122149. [PMID: 27999416 PMCID: PMC5187949 DOI: 10.3390/ijms17122149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 11/28/2016] [Accepted: 12/06/2016] [Indexed: 11/26/2022] Open
Abstract
Current genetically-engineered mouse melanoma models are often based on Tyr::CreERT2-controlled MAPK pathway activation by the BRAFV600E mutation and PI3K pathway activation by loss of PTEN. The major drawback of these models is the occurrence of spontaneous tumors caused by leakiness of the Tyr::CreERT2 system, hampering long-term experiments. To address this problem, we investigated several approaches to optimally provide local delivery of Cre recombinase, including injection of lentiviral particles, DNA tattoo administration and particle-mediated gene transfer, to induce melanomas in PtenLoxP/LoxP;BrafCA/+ mice lacking the Tyr::CreERT2 allele. We found that dermal delivery of the Cre recombinase gene under the control of a non-specific CAG promoter induced the formation of melanomas, but also keratoacanthoma and squamous cell carcinomas. Delivery of Cre recombinase DNA under the control of melanocyte-specific promoters in PtenLoxP/LoxP;BrafCA/+ mice resulted in sole melanoma induction. The growth rate and histological features of the induced tumors were similar to 4-hydroxytamoxifen-induced tumors in Tyr::CreERT2;PtenLoxP/LoxP;BrafCA/+ mice, while the onset of spontaneous tumors was prevented completely. These novel induction methods will allow long-term experiments in mouse models of skin malignancies.
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Affiliation(s)
- Marcel A Deken
- Department of Immunology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
| | - Ji-Ying Song
- Department of Experimental Animal Pathology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
| | - Jules Gadiot
- Department of Immunology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
| | - Adriaan D Bins
- Division of Medical Oncology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
| | - Paula Kroon
- Department of Immunology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
| | - Inge Verbrugge
- Department of Immunology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
| | - Christian U Blank
- Department of Immunology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
- Department of Medical Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
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Analysis of compound heterozygotes reveals that the mouse floxed Pax6 (tm1Ued) allele produces abnormal eye phenotypes. Transgenic Res 2016; 25:679-92. [PMID: 27240603 PMCID: PMC5023747 DOI: 10.1007/s11248-016-9962-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/13/2016] [Indexed: 01/27/2023]
Abstract
Analysis of abnormal phenotypes produced by different types of mutations has been crucial for our understanding of gene function. Some floxed alleles that retain a neomycin-resistance selection cassette (neo cassette) are not equivalent to wild-type alleles and provide useful experimental resources. Pax6 is an important developmental gene and the aim of this study was to determine whether the floxed Pax6tm1Ued (Pax6fl) allele, which has a retained neo cassette, produced any abnormal eye phenotypes that would imply that it differs from the wild-type allele. Homozygous Pax6fl/fl and heterozygous Pax6fl/+ mice had no overt qualitative eye abnormalities but morphometric analysis showed that Pax6fl/fl corneas tended be thicker and smaller in diameter. To aid identification of weak effects, we produced compound heterozygotes with the Pax6Sey-Neu (Pax6−) null allele. Pax6fl/− compound heterozygotes had more severe eye abnormalities than Pax6+/− heterozygotes, implying that Pax6fl differs from the wild-type Pax6+ allele. Immunohistochemistry showed that the Pax6fl/− corneal epithelium was positive for keratin 19 and negative for keratin 12, indicating that it was abnormally differentiated. This Pax6fl allele provides a useful addition to the existing Pax6 allelic series and this study demonstrates the utility of using compound heterozygotes with null alleles to unmask cryptic effects of floxed alleles.
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Characterization of the Promoter Regions of Two Sheep Keratin-Associated Protein Genes for Hair Cortex-Specific Expression. PLoS One 2016; 11:e0153936. [PMID: 27100288 PMCID: PMC4839604 DOI: 10.1371/journal.pone.0153936] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 04/06/2016] [Indexed: 11/19/2022] Open
Abstract
The keratin-associated proteins (KAPs) are the structural proteins of hair fibers and are thought to play an important role in determining the physical properties of hair fibers. These proteins are activated in a striking sequential and spatial pattern in the keratinocytes of hair fibers. Thus, it is important to elucidate the mechanism that underlies the specific transcriptional activity of these genes. In this study, sheep KRTAP 3–3 and KRTAP11-1 genes were found to be highly expressed in wool follicles in a tissue-specific manner. Subsequently, the promoter regions of the two genes that contained the 5′ flanking/5′ untranslated regions and the coding regions were cloned. Using an in vivo transgenic approach, we found that the promoter regions from the two genes exhibited transcriptional activity in hair fibers. A much stronger and more uniformly expressed green fluorescent signal was observed in the KRTAP11-1-ZsGreen1 transgenic mice. In situ hybridization revealed the symmetrical expression of sheep KRTAP11-1 in the entire wool cortex. Consistently, immunohistochemical analysis demonstrated that the pattern of ZsGreen1 expression in the hair cortex of transgenic mice matches that of the endogenous KRTAP11-1 gene, indicating that the cloned promoter region contains elements that are sufficient to govern the wool cortex-specific transcription of KRTAP11-1. Furthermore, regulatory regions in the 5′ upstream sequence of the sheep KRTAP11-1 gene that may regulate the observed hair keratinocyte specificity were identified using in vivo reporter assays.
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Osada SI, Minematsu N, Oda F, Akimoto K, Kawana S, Ohno S. Atypical Protein Kinase C Isoform, aPKCλ, Is Essential for Maintaining Hair Follicle Stem Cell Quiescence. J Invest Dermatol 2015; 135:2584-2592. [PMID: 26076315 DOI: 10.1038/jid.2015.222] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 04/11/2015] [Accepted: 04/23/2015] [Indexed: 11/09/2022]
Abstract
The atypical protein kinase C (aPKC)-partition-defective (PAR) complex regulates the formation of tight junctions and apico-basal epithelial polarity. To examine the role of this complex in the epidermis, we generated mutant mice harboring epidermal-specific deletion of aPKCλ (conditional knock-out (cKO)), a major component of the aPKC-PAR complex. The mutant mice exhibited abnormal hair follicle (HF) cycling, progressive losses of pelage hairs and vibrissae, and altered differentiation into the epidermis and sebaceous gland. We found that in the aPKCλ cKO mice HF stem cell (HFSC) quiescence was lost, as revealed by the decreased expression level of quiescence-inducing factors (Fgf18 and Bmp6) produced in Keratin 6-positive bulge stem cells. The loss of quiescence dysregulated the HFSC marker expression and led to the increase in Lrig1-positive cells, inducing hyperplasia of the interfollicular epidermis and sebaceous glands, and drove an increase in Lef1-positive matrix cells, causing a prolonged anagen-like phase. Persistent bulge stem cell activation led to a gradual depletion of CD34- and α6 integrin-positive HFSC reservoirs. These results suggest that aPKCλ regulates signaling pathways implicated in HFSC quiescence.
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Affiliation(s)
- Shin-Ichi Osada
- Department of Dermatology, Nippon Medical School, Tokyo, Japan.
| | - Naoko Minematsu
- Department of Dermatology, Nippon Medical School, Tokyo, Japan
| | - Fumino Oda
- Department of Dermatology, Nippon Medical School, Tokyo, Japan
| | - Kazunori Akimoto
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Japan
| | - Seiji Kawana
- Department of Dermatology, Nippon Medical School, Tokyo, Japan
| | - Shigeo Ohno
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Japan.
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Van de Laar E, Clifford M, Hasenoeder S, Kim BR, Wang D, Lee S, Paterson J, Vu NM, Waddell TK, Keshavjee S, Tsao MS, Ailles L, Moghal N. Cell surface marker profiling of human tracheal basal cells reveals distinct subpopulations, identifies MST1/MSP as a mitogenic signal, and identifies new biomarkers for lung squamous cell carcinomas. Respir Res 2014; 15:160. [PMID: 25551685 PMCID: PMC4343068 DOI: 10.1186/s12931-014-0160-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 12/17/2014] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The large airways of the lungs (trachea and bronchi) are lined with a pseudostratified mucociliary epithelium, which is maintained by stem cells/progenitors within the basal cell compartment. Alterations in basal cell behavior can contribute to large airway diseases including squamous cell carcinomas (SQCCs). Basal cells have traditionally been thought of as a uniform population defined by basolateral position, cuboidal cell shape, and expression of pan-basal cell lineage markers like KRT5 and TP63. While some evidence suggests that basal cells are not all functionally equivalent, few heterogeneously expressed markers have been identified to purify and study subpopulations. In addition, few signaling pathways have been identified that regulate their cell behavior. The goals of this work were to investigate tracheal basal cell diversity and to identify new signaling pathways that regulate basal cell behavior. METHODS We used flow cytometry (FACS) to profile cell surface marker expression at a single cell level in primary human tracheal basal cell cultures that maintain stem cell/progenitor activity. FACS results were validated with tissue staining, in silico comparisons with normal basal cell and lung cancer datasets, and an in vitro proliferation assay. RESULTS We identified 105 surface markers, with 47 markers identifying potential subpopulations. These subpopulations generally fell into more (~ > 13%) or less abundant (~ < 6%) groups. Microarray gene expression profiling supported the heterogeneous expression of these markers in the total population, and immunostaining of large airway tissue suggested that some of these markers are relevant in vivo. 24 markers were enriched in lung SQCCs relative to adenocarcinomas, with four markers having prognostic significance in SQCCs. We also identified 33 signaling receptors, including the MST1R/RON growth factor receptor, whose ligand MST1/MSP was mitogenic for basal cells. CONCLUSION This work provides the largest description to date of molecular diversity among human large airway basal cells. Furthermore, these markers can be used to further study basal cell function in repair and disease, and may aid in the classification and study of SQCCs.
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Affiliation(s)
- Emily Van de Laar
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Monica Clifford
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Stefan Hasenoeder
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
- />Present address: Helmholtz Zentrum München, Institute of Stem Cell Research, Ingolstädter Landstrasse 1, 85746 Neuherberg, Germany
| | - Bo Ram Kim
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Dennis Wang
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Sharon Lee
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
- />Department of Applied Mathematics, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 Canada
| | - Josh Paterson
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Nancy M Vu
- />Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112 USA
- />Present address: University of Utah School of Medicine, Salt Lake City, UT 84132 USA
| | - Thomas K Waddell
- />Toronto Lung Transplant Program, University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Shaf Keshavjee
- />Toronto Lung Transplant Program, University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Ming-Sound Tsao
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Laurie Ailles
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
| | - Nadeem Moghal
- />Department of Medical Biophysics, Ontario Cancer Institute/Campbell Family Cancer Research Institute/Princess Margaret Cancer Centre/University Health Network, University of Toronto, Toronto, ON M5G 1 L7 Canada
- />Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112 USA
- />Present address: Ontario Cancer Institute and Princess Margaret Hospital, University Health Network, Toronto, ON M5G 1 L7 Canada
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Dhouailly D, Pearton DJ, Michon F. The vertebrate corneal epithelium: From early specification to constant renewal. Dev Dyn 2014; 243:1226-41. [DOI: 10.1002/dvdy.24179] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 08/06/2014] [Accepted: 08/09/2014] [Indexed: 12/30/2022] Open
Affiliation(s)
- Danielle Dhouailly
- University Joseph Fourier; AGIM FRE CNRS 3405 Site Santé Centre Jean Roget La Tronche France
| | - David J. Pearton
- Oceanographic Research Institute; Marine Parade Durban South Africa
| | - Frederic Michon
- Institute of Biotechnology; Developmental Biology Program; University of Helsinki; Helsinki Finland
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Li X, Rossen N, Sinn PL, Hornick AL, Steines BR, Karp PH, Ernst SE, Adam RJ, Moninger TO, Levasseur DN, Zabner J. Integrin α6β4 identifies human distal lung epithelial progenitor cells with potential as a cell-based therapy for cystic fibrosis lung disease. PLoS One 2013; 8:e83624. [PMID: 24349537 PMCID: PMC3861522 DOI: 10.1371/journal.pone.0083624] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 11/10/2013] [Indexed: 12/21/2022] Open
Abstract
To develop stem/progenitor cell-based therapy for cystic fibrosis (CF) lung disease, it is first necessary to identify markers of human lung epithelial progenitor/stem cells and to better understand the potential for differentiation into distinct lineages. Here we investigated integrin α6β4 as an epithelial progenitor cell marker in the human distal lung. We identified a subpopulation of α6β4+ cells that localized in distal small airways and alveolar walls and were devoid of pro-surfactant protein C expression. The α6β4+ epithelial cells demonstrated key properties of stem cells ex vivo as compared to α6β4- epithelial cells, including higher colony forming efficiency, expression of stem cell-specific transcription factor Nanog, and the potential to differentiate into multiple distinct lineages including basal and Clara cells. Co-culture of α6β4+ epithelial cells with endothelial cells enhanced proliferation. We identified a subset of adeno-associated virus (AAVs) serotypes, AAV2 and AAV8, capable of transducing α6β4+ cells. In addition, reconstitution of bronchi epithelial cells from CF patients with only 5% normal α6β4+ epithelial cells significantly rescued defects in Cl- transport. Therefore, targeting the α6β4+ epithelial population via either gene delivery or progenitor cell-based reconstitution represents a potential new strategy to treat CF lung disease.
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Affiliation(s)
- Xiaopeng Li
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail: (XL); (JZ)
| | - Nathan Rossen
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Patrick L. Sinn
- Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Andrew L. Hornick
- Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Benjamin R. Steines
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Philip H. Karp
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Sarah E. Ernst
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Ryan J. Adam
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Thomas O. Moninger
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Dana N. Levasseur
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Joseph Zabner
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail: (XL); (JZ)
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Role of stat3 in skin carcinogenesis: insights gained from relevant mouse models. J Skin Cancer 2013; 2013:684050. [PMID: 23577258 PMCID: PMC3618941 DOI: 10.1155/2013/684050] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 02/20/2013] [Indexed: 01/24/2023] Open
Abstract
Signal transducer and activator of transcription 3 (Stat3) is a cytoplasmic protein that is activated in response to cytokines and growth factors and acts as a transcription factor. Stat3 plays critical roles in various biological activities including cell proliferation, migration, and survival. Studies using keratinocyte-specific Stat3-deficient mice have revealed that Stat3 plays an important role in skin homeostasis including keratinocyte migration, wound healing, and hair follicle growth. Use of both constitutive and inducible keratinocyte-specific Stat3-deficient mouse models has demonstrated that Stat3 is required for both the initiation and promotion stages of multistage skin carcinogenesis. Further studies using a transgenic mouse model with a gain of function mutant of Stat3 (Stat3C) expressed in the basal layer of the epidermis revealed a novel role for Stat3 in skin tumor progression. Studies using similar Stat3-deficient and gain-of-function mouse models have indicated its similar roles in ultraviolet B (UVB) radiation-mediated skin carcinogenesis. This paper summarizes the use of these various mouse models for studying the role and underlying mechanisms for the function of Stat3 in skin carcinogenesis. Given its significant role throughout the skin carcinogenesis process, Stat3 is an attractive target for skin cancer prevention and treatment.
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Axlund SD, Yoo BH, Rosen RB, Schaack J, Kabos P, Labarbera DV, Sartorius CA. Progesterone-inducible cytokeratin 5-positive cells in luminal breast cancer exhibit progenitor properties. Discov Oncol 2012. [PMID: 23184698 DOI: 10.1007/s12672-012-0127-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Progestins play a deleterious role in the onset of breast cancer, yet their influence on existing breast cancer and tumor progression is not well understood. In luminal estrogen receptor (ER)- and progesterone receptor (PR)-positive breast cancer, progestins induce a fraction of cells to express cytokeratin 5 (CK5), a marker of basal epithelial and progenitor cells in the normal breast. CK5(+) cells lose expression of ER and PR and are relatively quiescent, increasing their resistance to endocrine and chemotherapy compared to intratumoral CK5(-)ER(+)PR(+) cells. Characterization of live CK5(+) cells has been hampered by a lack of means for their direct isolation. Here, we describe optical (GFP) and bioluminescent (luciferase) reporter models to quantitate and isolate CK5(+) cells in luminal breast cancer cell lines utilizing the human KRT5 gene promoter and a viral vector approach. Using this system, we confirmed that the induction of GFP(+)/CK5(+) cells is specific to progestins, is dependent on PR, can be blocked by antiprogestins, and does not occur with other steroid hormones. Progestin-induced, fluorescence-activated cell sorting-isolated CK5(+) cells had lower ER and PR mRNA, were slower cycling, and were relatively more invasive and sphere forming than their CK5(-) counterparts in vitro. Repeated progestin treatment and selection of GFP(+) cells enriched for a persistent population of CK5(+) cells, suggesting that this transition can be semi-permanent. These data support that in PR(+) breast cancers, progestins induce a subpopulation of CK5(+)ER(-)PR(-) cells with enhanced progenitor properties and have implications for treatment resistance and recurrence in luminal breast cancer.
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Affiliation(s)
- Sunshine Daddario Axlund
- Department of Pathology, University of Colorado Denver, Anschutz Medical Center, Aurora, CO, USA
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Nakamura M, Schneider MR, Schmidt-Ullrich R, Paus R. Mutant laboratory mice with abnormalities in hair follicle morphogenesis, cycling, and/or structure: an update. J Dermatol Sci 2012; 69:6-29. [PMID: 23165165 DOI: 10.1016/j.jdermsci.2012.10.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 10/02/2012] [Accepted: 10/04/2012] [Indexed: 12/17/2022]
Abstract
Human hair disorders comprise a number of different types of alopecia, atrichia, hypotrichosis, distinct hair shaft disorders as well as hirsutism and hypertrichosis. Their causes vary from genodermatoses (e.g. hypotrichoses) via immunological disorders (e.g. alopecia areata, autoimmune cicatrical alopecias) to hormone-dependent abnormalities (e.g. androgenetic alopecia). A large number of spontaneous mouse mutants and genetically engineered mice develop abnormalities in hair follicle morphogenesis, cycling, and/or hair shaft formation, whose analysis has proven invaluable to define the molecular regulation of hair growth, ranging from hair follicle development, and cycling to hair shaft formation and stem cell biology. Also, the accumulating reports on hair phenotypes of mouse strains provide important pointers to better understand the molecular mechanisms underlying human hair growth disorders. Since numerous new mouse mutants with a hair phenotype have been reported since the publication of our earlier review on this matter a decade ago, we present here an updated, tabulated mini-review. The updated annotated tables list a wide selection of mouse mutants with hair growth abnormalities, classified into four categories: Mutations that affect hair follicle (1) morphogenesis, (2) cycling, (3) structure, and (4) mutations that induce extrafollicular events (for example immune system defects) resulting in secondary hair growth abnormalities. This synthesis is intended to provide a useful source of reference when studying the molecular controls of hair follicle growth and differentiation, and whenever the hair phenotypes of a newly generated mouse mutant need to be compared with existing ones.
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Affiliation(s)
- Motonobu Nakamura
- Department of Dermatology, University of Occupational and Environmental Health, Kitakyushu, Japan.
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Moriyasu M, Makanae A, Satoh A. Spatiotemporal regulation of keratin 5 and 17 in the axolotl limb. Dev Dyn 2012; 241:1616-24. [PMID: 22836940 DOI: 10.1002/dvdy.23839] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2012] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Amphibians have greater regeneration capability than higher vertebrates. They can regenerate their limbs after an amputation. As a limb is regenerated, a regeneration-specific epithelium called the apical epithelial cap (AEC) is induced. The AEC is an essential structure for limb regeneration. Despite the importance of the AEC, molecular marker genes have not been well studied at the molecular level. RESULTS In the present study, keratin5 (KRT5) and KRT17 were investigated in an axolotl-regenerating limb. KRT5 and KRT17 were expressed in a regenerating limb but down-regulated in a differentiating limb. KRT5 showed characteristic regulation in a regenerating blastema. KRT5 was suppressed in the basal layer of the AEC. This KRT5 suppression was correlated to the blastema differentiation and nerve presence. Simple skin wounding could also upregulate both KRT5 and KRT17 gene expression. But these genes were suppressed within a shorter time than in limb regeneration. CONCLUSIONS The KRT5 and KRT17 gene profile can be a useful marker gene to investigate AEC in limb regeneration.
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Affiliation(s)
- Miyuki Moriyasu
- Okayama University, Research Core for Interdisciplinary Sciences (RCIS), Okayama, Japan
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Yang L, Li W, Wang S, Wang L, Li Y, Yang X, Peng R. Smad4 disruption accelerates keratinocyte reepithelialization in murine cutaneous wound repair. Histochem Cell Biol 2012; 138:573-82. [PMID: 22644379 DOI: 10.1007/s00418-012-0974-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2012] [Indexed: 12/28/2022]
Abstract
Keratinocyte reepithelialization is a rate-limiting event in cutaneous wound repair, which involves the migration and proliferation of keratinocytes to cover the denuded dermal surface. Transforming growth factor-β1 (TGF-β1) has the ability to induce epithelial cell migration while inhibiting proliferation, and controversial results have been generated regarding the effect of TGF-β signaling on reepithelialization. In this study, full-thickness skin wounds were made in keratinocyte-specific Smad4 knockout and the control mice. The wound closure, reepithelialization, keratinocyte proliferation, myofibroblast numbers and collagen deposition of were assessed. The results showed that the proliferation of keratinocytes increased, which accelerated the reepithelialization, and led to faster wound repair in the epidermis of Smad4 mutant mice. Upregulation of keratin 17, 14-3-3 sigma and phosphorylated AKT in the hyperproliferative epidermis may be correlated with the accelerated reepithelialization. We conclude that Smad4 plays an inhibitory role in the keratinocyte-mediated reepithelialization of wound healing.
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Affiliation(s)
- Leilei Yang
- Beijing Institute of Radiation Medicine, 27 Tai-Ping Road, Beijing 100850, People's Republic of China
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15
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Schneider MR. Genetic mouse models for skin research: strategies and resources. Genesis 2012; 50:652-64. [PMID: 22467532 DOI: 10.1002/dvg.22029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 03/20/2012] [Accepted: 03/24/2012] [Indexed: 12/16/2022]
Abstract
A number of features contributed to establishing the mouse as the favorite model organism for skin research: the genetic and pathophysiological similarities to humans, the small size and relatively short reproductive period, meaning low maintenance costs, and the availability of sophisticated tools for manipulating the genome, gametes, and embryos. While initial studies depended on strains displaying skin abnormalities due to spontaneous genetic mutations, the availability of the transgenic and knockout technologies and their astonishing perfection during the last decades allowed the development of mouse lines permitting any imaginable genetic modification including gene inactivation, substitution, modification, or overexpression. While these technologies have already contributed to the functional analysis of several genes and processes related to skin research, continued progress requires understanding, awareness, and access to these mouse resources. This review will identify the strategies currently employed for the genetic manipulation of mice in skin research, and outline current resources and their limitations.
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Affiliation(s)
- Marlon R Schneider
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany.
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16
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Mort RL, Douvaras P, Morley SD, Dorà N, Hill RE, Collinson JM, West JD. Stem cells and corneal epithelial maintenance: insights from the mouse and other animal models. Results Probl Cell Differ 2012; 55:357-94. [PMID: 22918816 PMCID: PMC3471528 DOI: 10.1007/978-3-642-30406-4_19] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Maintenance of the corneal epithelium is essential for vision and is a dynamic process incorporating constant cell production, movement and loss. Although cell-based therapies involving the transplantation of putative stem cells are well advanced for the treatment of human corneal defects, the scientific understanding of these interventions is poor. No definitive marker that discriminates stem cells that maintain the corneal epithelium from the surrounding tissue has been discovered and the identity of these elusive cells is, therefore, hotly debated. The key elements of corneal epithelial maintenance have long been recognised but it is still not known how this dynamic balance is co-ordinated during normal homeostasis to ensure the corneal epithelium is maintained at a uniform thickness. Most indirect experimental evidence supports the limbal epithelial stem cell (LESC) hypothesis, which proposes that the adult corneal epithelium is maintained by stem cells located in the limbus at the corneal periphery. However, this has been challenged recently by the corneal epithelial stem cell (CESC) hypothesis, which proposes that during normal homeostasis the mouse corneal epithelium is maintained by stem cells located throughout the basal corneal epithelium with LESCs only contributing during wound healing. In this chapter we review experimental studies, mostly based on animal work, that provide insights into how stem cells maintain the normal corneal epithelium and consider the merits of the alternative LESC and CESC hypotheses. Finally, we highlight some recent research on other stem cell systems and consider how this could influence future research directions for identifying the stem cells that maintain the corneal epithelium.
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Rawlins EL, Perl AK. The a"MAZE"ing world of lung-specific transgenic mice. Am J Respir Cell Mol Biol 2011; 46:269-82. [PMID: 22180870 DOI: 10.1165/rcmb.2011-0372ps] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The purpose of this review is to give a comprehensive overview of transgenic mouse lines suitable for studying gene function and cellular lineage relationships in lung development, homeostasis, injury, and repair. Many of the mouse strains reviewed in this Perspective have been widely shared within the lung research community, and new strains are continuously being developed. There are many transgenic lines that target subsets of lung cells, but it remains a challenge for investigators to select the correct transgenic modules for their experiment. This review covers the tetracycline- and tamoxifen-inducible systems and focuses on conditional lines that target the epithelial cells. We point out the limitations of each strain so investigators can choose the system that will work best for their scientific question. Current mesenchymal and endothelial lines are limited by the fact that they are not lung specific. These lines are summarized in a brief overview. In addition, useful transgenic reporter mice for studying lineage relationships, promoter activity, and signaling pathways will complete our lung-specific conditional transgenic mouse shopping list.
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Affiliation(s)
- Emma L Rawlins
- Children's Hospital Medical Center, Divisions of Neonatology and Pulmonary Biology, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
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18
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Interferon regulatory factor 6 is necessary, but not sufficient, for keratinocyte differentiation. J Invest Dermatol 2011; 132:50-8. [PMID: 21918538 PMCID: PMC3237898 DOI: 10.1038/jid.2011.272] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Regulation of epidermal proliferation and differentiation is critical for maintenance of cutaneous homeostasis. Interferon Regulatory Factor 6 (Irf6)-deficient mice die perinatally and exhibit ectopic proliferation and defective epidermal differentiation. We sought to determine whether these disruptions of epidermal function were cell autonomous, and used embryonic Irf6(-/-) keratinocytes to understand the specific role of Irf6 in keratinocyte proliferation and differentiation. In the absence of Irf6, keratinocytes exhibited a heterogeneous phenotype with the presence of large cells. Irf6(-/-) keratinocytes displayed increased colony-forming efficiency compared with wild-type cells, suggesting that Irf6 represses long-term proliferation. Irf6 was present at low levels in wild-type keratinocytes in culture, and upregulated after induction of differentiation in vitro, along with upregulation of markers of early differentiation. However, Irf6(-/-) keratinocytes did not express markers of terminal differentiation. Overexpression of Irf6 in wild-type keratinocytes was insufficient to induce expression of markers of differentiation under growing conditions. Together, these results indicated that Irf6 is necessary, but not sufficient, for keratinocyte differentiation. Finally, using a transgenic mouse expressing Lac-Z under the regulation of an enhancer element 9.7 kb upstream of the Irf6 start site, we demonstrated that this element contributes to the regulation of Irf6 in the epidermis and keratinocytes in culture.
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19
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Douvaras P, Webb S, Whitaker DA, Dorà N, Hill RE, Dorin JR, West JD. Rare corneal clones in mice suggest an age-related decrease of stem cell activity and support the limbal epithelial stem cell hypothesis. Stem Cell Res 2011; 8:109-19. [PMID: 22099025 DOI: 10.1016/j.scr.2011.08.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 08/05/2011] [Accepted: 08/27/2011] [Indexed: 01/10/2023] Open
Abstract
The anterior ocular surface comprises the cornea, conjunctiva and a narrow intermediate region called the limbus. It is widely accepted that the corneal epithelium is maintained by stem cells but different hypotheses propose that the stem cells that maintain the mouse corneal epithelium during normal homeostasis are located either in the basal limbal epithelium or throughout the basal corneal epithelium. There are no specific markers to help test these alternatives and new methods are required to distinguish between them. We observed that KRT5(LacZ/-) transgenic mice produced rare β-galactosidase (β-gal)-positive radial stripes in the corneal epithelium. These stripes are likely to be clonal lineages of cells derived from stem cells, so they provide a lineage marker for actively proliferating stem cells. The distributions of the β-gal-positive radial stripes suggested they extended centripetally from the limbus, supporting the limbal epithelial stem cell (LESC) hypothesis. Stripe frequency declined between 15 and 30 weeks, which predicts a reduction in stem cell function with age. Pax6(+/-), KRT5(LacZ/-) corneas had small patches rather than stripes, which confirms that corneal maintenance is abnormal in Pax6(+/-) mice.
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Affiliation(s)
- Panagiotis Douvaras
- Division of Reproductive and Developmental Sciences, Genes and Development Group, University of Edinburgh, Edinburgh EH8 9XD, Scotland, UK
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20
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Crabtree JS, Kilbourne EJ, Peano BJ, Chippari S, Kenney T, McNally C, Wang W, Harris HA, Winneker RC, Nagpal S, Thompson CC. A mouse model of androgenetic alopecia. Endocrinology 2010; 151:2373-80. [PMID: 20233794 DOI: 10.1210/en.2009-1474] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Androgenetic alopecia (AGA), commonly known as male pattern baldness, is a form of hair loss that occurs in both males and females. Although the exact cause of AGA is not known, it is associated with genetic predisposition through traits related to androgen synthesis/metabolism and androgen signaling mediated by the androgen receptor (AR). Current therapies for AGA show limited efficacy and are often associated with undesirable side effects. A major hurdle to developing new therapies for AGA is the lack of small animal models to support drug discovery research. Here, we report the first rodent model of AGA. Previous work demonstrating that the interaction between androgen-bound AR and beta-catenin can inhibit Wnt signaling led us to test the hypothesis that expression of AR in hair follicle cells could interfere with hair growth in an androgen-dependent manner. Transgenic mice overexpressing human AR in the skin under control of the keratin 5 promoter were generated. Keratin 5-human AR transgenic mice exposed to high levels of 5alpha-dihydrotestosterone showed delayed hair regeneration, mimicking the AGA scalp. This effect is AR mediated, because treatment with the AR antagonist hydroxyflutamide inhibited the effect of dihydrotestosterone on hair growth. These results support the hypothesis that androgen-mediated hair loss is AR dependent and suggest that AR and beta-catenin mediate this effect. These mice can now be used to test new therapeutic agents for the treatment of AGA, accelerating the drug discovery process.
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Affiliation(s)
- Judy S Crabtree
- Department of Tissue Repair, Wyeth Research, Collegeville, Pennsylvania 19426, USA
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Michaelis K, Wallbrecht K, Kerstan A, Beyersdorf N, Williams C, Kerkau T, Wang XJ, Hünig T, Schön MP. Modulating T cell functions does not alleviate chronic inflammatory skin lesions in K5.TGFβ1 transgenic mice. Exp Dermatol 2010; 19:406-15. [DOI: 10.1111/j.1600-0625.2009.01031.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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22
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McCalla-Martin AC, Chen X, Linder KE, Estrada JL, Piedrahita JA. Varying phenotypes in swine versus murine transgenic models constitutively expressing the same human Sonic hedgehog transcriptional activator, K5-HGLI2 Delta N. Transgenic Res 2010; 19:869-87. [PMID: 20099029 DOI: 10.1007/s11248-010-9362-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Accepted: 01/04/2010] [Indexed: 01/27/2023]
Abstract
This study was undertaken to characterize the effects of constitutive expression of the hedgehog transcriptional activator, Gli2, in porcine skin. The keratinocyte-specific human transgene, K5-hGli2 Delta N, was used to produce transgenic porcine lines via somatic cell nuclear transfer techniques. In mice, K5-hGli2 Delta N induces epithelial downgrowths resembling basal cell carcinomas. Our porcine model also developed these basal cell carcinoma-like lesions, however gross tumor development was not appreciated. In contrast to the murine model, diffuse epidermal changes as well as susceptibility to cutaneous infections were seen in the swine model. Histologic analysis of transgenic piglets revealed generalized epidermal changes including: epidermal hyperplasia (acanthosis), elongated rete ridges, parakeratotic hyperkeratosis, epidermal neutrophilic infiltration, capillary loop dilation and hypogranulosis. By 2 weeks of age, the transgenic piglets developed erythematic and edematous lesions at high contact epidermal areas and extensor surfaces of distal limb joints. Despite antibiotic treatment, these lesions progressed to a deep bacterial pyoderma and pigs died or were euthanized within weeks of birth. Non-transgenic littermates were phenotypically normal by gross and histological analysis. In summary, constitutive expression of the human hGli2 Delta N in keratinocytes, results in cutaneous changes that have not been reported in the K5-hGli2 Delta N murine model. These findings indicate a need for a multiple species animal model approach in order to better understand the role of Gli2 in mammalian skin.
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Affiliation(s)
- Amy C McCalla-Martin
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA
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23
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Levin MD, Lu MM, Petrenko NB, Hawkins BJ, Gupta TH, Lang D, Buckley PT, Jochems J, Liu F, Spurney CF, Yuan LJ, Jacobson JT, Brown CB, Huang L, Beermann F, Margulies KB, Madesh M, Eberwine JH, Epstein JA, Patel VV. Melanocyte-like cells in the heart and pulmonary veins contribute to atrial arrhythmia triggers. J Clin Invest 2009; 119:3420-36. [PMID: 19855129 DOI: 10.1172/jci39109] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 08/25/2009] [Indexed: 01/27/2023] Open
Abstract
Atrial fibrillation is the most common clinical cardiac arrhythmia. It is often initiated by ectopic beats arising from the pulmonary veins and atrium, but the source and mechanism of these beats remains unclear. The melanin synthesis enzyme dopachrome tautomerase (DCT) is involved in intracellular calcium and reactive species regulation in melanocytes. Given that dysregulation of intracellular calcium and reactive species has been described in patients with atrial fibrillation, we investigated the role of DCT in this process. Here, we characterize a unique DCT-expressing cell population within murine and human hearts that populated the pulmonary veins, atria, and atrioventricular canal. Expression profiling demonstrated that this population expressed adrenergic and muscarinic receptors and displayed transcriptional profiles distinct from dermal melanocytes. Adult mice lacking DCT displayed normal cardiac development but an increased susceptibility to atrial arrhythmias. Cultured primary cardiac melanocyte-like cells were excitable, and those lacking DCT displayed prolonged repolarization with early afterdepolarizations. Furthermore, mice with mutations in the tyrosine kinase receptor Kit lacked cardiac melanocyte-like cells and did not develop atrial arrhythmias in the absence of DCT. These data suggest that dysfunction of melanocyte-like cells in the atrium and pulmonary veins may contribute to atrial arrhythmias.
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Affiliation(s)
- Mark D Levin
- Penn Cardiovascular Institute and University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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24
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García-Villegas R, Escamilla J, Sánchez-Guzmán E, Pastén A, Hernández-Quintero M, Gómez-Flores E, Castro-Muñozledo F. Pax-6 is expressed early in the differentiation of a corneal epithelial model system. J Cell Physiol 2009; 220:348-56. [DOI: 10.1002/jcp.21771] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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25
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Chen X, Schneider-Broussard R, Hollowell D, McArthur M, Jeter CR, Benavides F, DiGiovanni J, Tang DG. Abnormal differentiation, hyperplasia and embryonic/perinatal lethality in BK5-T/t transgenic mice. Differentiation 2008; 77:324-34. [PMID: 19272531 DOI: 10.1016/j.diff.2008.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 08/28/2008] [Accepted: 10/02/2008] [Indexed: 01/20/2023]
Abstract
The cell-of-origin has a great impact on the types of tumors that develop and the stem/progenitor cells have long been considered main targets of malignant transformation. The SV40 (SV40-Simian Virus 40) large T and small t antigens (T/t), have been targeted to multiple-differentiated cellular compartments in transgenic mice. In most of these studies, transgenic animals develop tumors without apparent defects in animal development. In this study, we used the bovine keratin 5 (BK5) promoter to target the T/t antigens to stem/progenitor cell-containing cytokeratin 5 (CK5) cellular compartment. A transgene construct, BK5-T/t, was made and microinjected into the male pronucleus of FVB/N mouse oocytes. After implanting approximately 1700 embryos, only 7 transgenics were obtained, including 4 embryos (E9.5, E13, E15, and E20) and 3 postnatal animals, which died at P1, P2, and P18, respectively. Immunohistological analysis revealed aberrant differentiation and prominent hyperplasia in several transgenic CK5 tissues, especially the upper digestive organs (tongue, oral mucosa, esophagus, and forestomach) and epidermis, the latter of which also showed focal dysplasia. Altogether, these results indicate that constitutive expression of the T/t antigens in CK5 cellular compartment results in abnormal epithelial differentiation and leads to embryonic/perinatal animal lethality.
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Affiliation(s)
- Xin Chen
- Department of Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, 1808 Park Road 1-C, P.O. Box 389, Smithville, TX 78957, USA
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26
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Yates CC, Whaley D, Y-Chen A, Kulesekaran P, Hebda PA, Wells A. ELR-negative CXC chemokine CXCL11 (IP-9/I-TAC) facilitates dermal and epidermal maturation during wound repair. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 173:643-52. [PMID: 18669615 DOI: 10.2353/ajpath.2008.070990] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In skin wounds, the chemokine CXCR3 receptor appears to play a key role in coordinating the switch from regeneration of the ontogenically distinct mesenchymal and epithelial compartments toward maturation. However, because CXCR3 equivalently binds four different ELR-devoid CXC chemokines (ie, PF4/CXCL4, IP-10/CXCL10, MIG/CXCL9, and IP-9/CXCL11), we sought to identify the ligand that coordinates epidermal coverage with the maturation of the underlying superficial dermis. Because CXCL11 (IP-9 or I-TAC) is produced by redifferentiating keratinocytes late in the regenerative phase when re-epithelialization is completed and matrix maturation ensues, we generated mice in which an antisense construct (IP-9AS) eliminated IP-9 expression during the wound-healing process. Both full and partial thickness excisional wounds were created and analyzed histologically throughout a 2-month period. Wound healing was impaired in the IP-9AS mice, with a hypercellular and immature dermis noted even after 60 days. Re-epithelialization was delayed with a deficient delineating basement membrane persisting in mice expressing the IP-9AS construct. Provisional matrix components persisted in the dermis, and the mature basement membrane components laminin V and collagen IV were severely diminished. Interestingly, the inflammatory response was not diminished despite IP-9/I-TAC being chemotactic for such cells. We conclude that IP-9 is a key ligand in the CXCR3 signaling system for wound repair, promoting re-epithelialization and modulating the maturation of the superficial dermis.
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Affiliation(s)
- Cecelia C Yates
- Department of Pathology, University of Pittsburgh and Pittsburgh Veteran's Administration Medical Center, Pittsburgh, Pennsylvania 15261, USA
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27
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Epidermal JunB represses G-CSF transcription and affects haematopoiesis and bone formation. Nat Cell Biol 2008; 10:1003-11. [PMID: 18641637 DOI: 10.1038/ncb1761] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Accepted: 06/10/2008] [Indexed: 11/09/2022]
Abstract
Mice that lack JunB in epidermal cells are born with normal skin; however, keratinocytes hyperproliferate in vitro and on TPA treatment in vivo. Loss of JunB expression in the epidermis of adult mice affects the skin, the proliferation of haematopoietic cells and bone formation. G-CSF is a direct transcriptional target of JunB and mutant epidermis releases large amounts of G-CSF that reach high systemic levels and cause skin ulcerations, myeloproliferative disease and low bone mass. The absence of G-CSF significantly improves hyperkeratosis and prevents the development of myeloproliferative disease, but does not affect bone loss. This study describes a mechanism by which the absence of JunB in epithelial cells causes multi-organ disease, suggesting that the epidermis can act as an endocrine-like organ.
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28
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Ackerl R, Walko G, Fuchs P, Fischer I, Schmuth M, Wiche G. Conditional targeting of plectin in prenatal and adult mouse stratified epithelia causes keratinocyte fragility and lesional epidermal barrier defects. J Cell Sci 2007; 120:2435-43. [PMID: 17606998 DOI: 10.1242/jcs.004481] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plectin, a widespread intermediate filament-based cytolinker protein capable of interacting with a variety of cytoskeletal structures and plasma membrane-bound junctional complexes, serves essential functions in maintenance of cell and tissue cytoarchitecture. We have generated a mouse line bearing floxed plectin alleles and conditionally deleted plectin in stratified epithelia. This strategy enabled us to study the consequences of plectin deficiency in this particular type of tissues in the context of the whole organism without plectin loss affecting other tissues. Conditional knockout mice died early after birth, showing signs of starvation and growth retardation. Blistering was observed on their extremities and on the oral epithelium after initial nursing, impairing food uptake. Knockout epidermis was very fragile and showed focal epidermal barrier defects caused by the presence of small skin lesions. Stratification, proliferation and differentiation of knockout skin seemed unaffected by epidermis-restricted plectin deficiency. In an additionally generated mouse model, tamoxifen-induced Cre-ER(T)-mediated recombination led to mice with a mosaic plectin deletion pattern in adult epidermis, combined with microblister formation and epidermal barrier defects. Our study explains the early lethality of plectin-deficient mice and provides a model to ablate plectin in adult animals which could be used for developing gene or pharmacological therapies.
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Affiliation(s)
- Reinhard Ackerl
- Department of Molecular Cell Biology, Max F. Perutz Laboratories, University of Vienna, 1030 Vienna, Austria
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29
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Evidence of EGR1 as a differentially expressed gene among proliferative skin diseases. Genomic Med 2007; 1:75-85. [PMID: 18923931 DOI: 10.1007/s11568-007-9010-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 07/03/2007] [Indexed: 01/26/2023] Open
Abstract
Hyperproliferative epidermal disorders range from benign hyperplasias such as psoriasis to basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), the two most common cancers in the US. While they all arise from the epidermis, these diseases differ dramatically in biological behavior and their underlying gene expression patterns have not been compared. We thus examined mRNA transcript levels in these disorders to identify and further characterize differentially expressed genes. Transcript expression patterns distinguish these disorders and identify EGR1, among other genes, whose epidermal expression is decreased in BCC and SCC but is elevated in psoriasis. Egr-1 inhibits growth of benign and malignant epidermal cells in vitro and appears to suppress both Cdc25A expression and Cdk2 dephosphorylation. These data indicate that gene expression profiling can differentiate epidermal hyperproliferative diseases and suggest that Egr-1 may play a role in preventing uncontrolled epidermal growth.
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30
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Wang YH, Chen YH, Lu JH, Lin YJ, Chang MY, Tsai HJ. Epidermis-restricted expression of zebrafish cytokeratin II is controlled by a -141/+85 minimal promoter, and cassette -141/-111 is essential for driving the tissue specificity. Differentiation 2007; 74:186-94. [PMID: 16683989 DOI: 10.1111/j.1432-0436.2006.00064.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We isolated a 2.3 kb DNA segment from the upstream region of the zebrafish cytokeratin II (zfCKII) gene. Transgenic embryos, produced by using a series of 5' deletions linked to the red fluorescent protein (RFP) reporter, showed that the -141/+85 segment of zfCKII directed RFP expression in epidermal cells, whereas the -111/+85 segment did not. When -141/-111 was deleted from -355/+85 and microinjected into one-celled embryos, no fluorescence was observed at later stages, indicating that the -141/-111 segment is required for green fluorescent protein expression in epidermal cells. Furthermore, when a putative KLF-binding site at -119/-117 was mutated, RFP expression rates and intensities were reduced dramatically, although still observed, suggesting that -119/-117 within -141/-111 is a key cis-element for controlling epidermis-specific expression of the zfCKII gene. Finally, we generated a zebrafish transgenic line, Tg(zfCKII(2.3):RFP), which carries an upstream 2.3 kb regulatory region of the zfCKII gene fused with RFP. The expression pattern in the epidermal cells of Tg(zfCKII(2.3):RFP) fish recapitulated that of the endogenous gene. F2 embryos derived from Tg(zfCKII(2.3):RFP) males crossed with wild-type females revealed that the earliest onset of RFP expression was at the sphere stage, indicating that this transgenic approach can be used for studying zygotic expression of maternally inherited genes.
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Affiliation(s)
- Yun-Hsin Wang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 106, Taiwan
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31
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Merritt AJ, Zhu K, Garrod DR, Chidgey MAJ. A 4kb Fragment of the Desmocollin 3 Promoter Directs Reporter Gene Expression to Parakeratotic Epidermis and Primary Hair Follicles. J Invest Dermatol 2007; 127:245-7. [PMID: 16841032 DOI: 10.1038/sj.jid.5700483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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32
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Abstract
The capacity to induce neoplasia in human tissue in the laboratory has recently provided a new platform for cancer research. Malignant conversion can be achieved in vivo by expressing genes of interest in human tissue that has been regenerated on immune-deficient mice. Induction of cancer in regenerated human skin recapitulates the three-dimensional architecture, tissue polarity, basement membrane structure, extracellular matrix, oncogene signalling and therapeutic target proteins found in intact human skin in vivo. Human-tissue cancer models therefore provide an opportunity to elucidate fundamental cancer mechanisms, to assess the oncogenic potency of mutations associated with specific human cancers and to develop new cancer therapies.
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Affiliation(s)
- Paul A Khavari
- Veterans Affairs, Palo Alto Healthcare System, Palo Alto, California 94304, USA.
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Abstract
Major progress in understanding epithelial skin stem cells has been accomplished. This has been possible by developing new methods for labeling, tracking, isolating, and characterizing enriched populations of stem cells. This chapter summarizes in vivo and in vitro assays that are currently employed to analyze skin epithelial stem cells. Despite progress, the definition of a stem cell is currently a functional one. Unambiguous identification of a stem cell in intact tissue is still not possible. These limitations hamper molecular studies aimed at unraveling the cellular mechanisms operating in the stem cell compartment. This chapter emphasizes current methods for analyzing hair follicle stem cells, as opposed to other epithelial compartments, because the hair follicle has been most intensively studied up to date.
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Affiliation(s)
- Tudorita Tumbar
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
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Lu H, Hesse M, Peters B, Magin TM. Type II keratins precede type I keratins during early embryonic development. Eur J Cell Biol 2005; 84:709-18. [PMID: 16180309 DOI: 10.1016/j.ejcb.2005.04.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We and others have recently demonstrated that the keratin (K) gene family in mammals is even more complex than previously thought [Eur. J. Cell Biol. 83, 19-26]. To address the function of keratins during early development, precise information on their spatio-temporal expression is required. Here, we examined the expression of selected mouse keratins from pre-implantation to mid-gestational embryonic stages using RT-PCR and immunofluorescence. At E0.5, transcripts encoding K5, K6, K7, K8, K14, K15, K18, and K19 are apparently absent. We report on a post-transcriptional regulation of type I keratins, preventing filament formation in 8- to 16-cell stage embryos. In these embryos, mRNAs coding for K7, K8, K18, and K19 are present, but only K7 and K8 are translated into protein which is deposited in aggregates. Following the accumulation of K18 protein at E3.5, keratin filaments are formed. Delayed onset of type I keratin protein expression was additionally observed in later embryonic stages for K5 and K14. K5 protein expression starts in the forelimb surface ectoderm as early as E9.25, while the expression of its partner, K14, begins at E9.75. From E9.25 to E9.75, K5 forms atypical filaments with K18. Remarkably, in embryonic K5-/- mice, K14 formed normal filaments until E12.5 despite the absence of its partner K5, due to the presence of K8. Following periderm formation, K14-containing filaments disappeared and K14 became localized in aggregates in basal keratinocytes. Despite the absence of a keratin cytoskeleton, there was no cytolysis. We suggest that the formation of the first embryonic cytoskeleton from soluble keratins is regulated by unknown mechanisms. Whether the premature expression of type II keratins relates to their proposed role in TNF- and Fas-mediated signalling is presently unknown.
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Affiliation(s)
- Hong Lu
- Institut für Physiologische Chemie, Abteilung für Zellbiochemie, Bonner Forum Biomedizin and LIMES, Universität Bonn, Bonn, Germany
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Tao J, Kuliyev E, Wang X, Li X, Wilanowski T, Jane SM, Mead PE, Cunningham JM. BMP4-dependent expression of Xenopus Grainyhead-like 1 is essential for epidermal differentiation. Development 2005; 132:1021-34. [PMID: 15705857 DOI: 10.1242/dev.01641] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Morphogen-dependent epidermal-specific transacting factors have not been defined in vertebrates. We demonstrate that a member of the grainyhead transcription factor family, Grainyhead-like 1 (XGrhl1) is essential for ectodermal ontogeny in Xenopus laevis. Expression of this factor is restricted to epidermal cells. Moreover, XGrhl1 is regulated by the BMP4 signaling cascade. Disruption of XGrhl1 activity in vivo results in a severe defect in terminal epidermal differentiation, with inhibition of XK81A1 epidermal keratin gene expression, a key target of BMP4 signaling. Furthermore, transcription of the XK81A1 gene is modulated directly by binding of XGRHL1 to a promoter-localized binding motif that is essential for high-level expression. These results establish a novel developmental role for XGrhl1 as a crucial tissue-specific regulator of vertebrate epidermal differentiation.
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Affiliation(s)
- Jianning Tao
- Department of Hematology/Oncology, St Jude Children's Research Hospital, Memphis, TN 38105, USA
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36
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Sinha S. Regulation of intermediate filament gene expression. Methods Cell Biol 2005; 78:267-96. [PMID: 15646622 DOI: 10.1016/s0091-679x(04)78010-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Affiliation(s)
- Satrajit Sinha
- Department of Biochemistry, State University of New York at Buffalo, Buffalo, New York 14214, USA
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Popa C, Dahler AL, Serewko-Auret MM, Wong CF, Smith L, Barnes LM, Strutton GM, Saunders NA. AP-2 transcription factor family member expression, activity, and regulation in human epidermal keratinocytes in vitro. Differentiation 2004; 72:185-97. [PMID: 15270775 DOI: 10.1111/j.1432-0436.2004.07205001.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The AP-2 transcription factor family is presumed to play an important role in the regulation of the keratinocyte squamous differentiation program; however, limited functional data are available to support this. In the present study, the activity and regulation of AP-2 were examined in differentiating human epidermal keratinocytes. We report that (1) AP-2 transcriptional activity decreases in differentiated keratinocytes but remains unchanged in differentiation-insensitive squamous cell carcinoma cell lines, (2) diminished AP-2 transcriptional activity is associated with a loss of specific DNA-bound AP-2 complexes, and (3) there is an increase in the ability of cytoplasmic extracts, derived from differentiated keratinocytes, to phosphorylate AP-2 alpha and AP-2 beta when cells differentiate. In contrast, extracts from differentiation-insensitive squamous cell carcinoma cells are unable to phosphorylate AP-2 proteins. Finally, the phosphorylation of recombinant AP-2 alpha by cytosolic extracts from differentiated keratinocytes is associated with decreased AP-2 DNA-binding activity. Combined, these data indicate that AP-2 trans-activation and DNA-binding activity decrease as keratinocytes differentiate, and that this decreased activity is associated with an enhanced ability to phosphorylate AP-2 alpha and beta.
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Affiliation(s)
- Claudia Popa
- Epithelial Pathobiology Group, Cancer Biology Program, Centre for Immunology and Cancer Research, University of Queensland, Building 1, R Wing, Level 4, Princess Alexandra Hospital, Brisbane, Queensland, Australia
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Schoch KG, Lori A, Burns KA, Eldred T, Olsen JC, Randell SH. A subset of mouse tracheal epithelial basal cells generates large colonies in vitro. Am J Physiol Lung Cell Mol Physiol 2004; 286:L631-42. [PMID: 12959927 DOI: 10.1152/ajplung.00112.2003] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Airway epithelial stem cells are not well characterized. To examine clonal growth potential, we diluted single, viable B6.129S7-Gtrosa26 (Rosa26) mouse tracheal epithelial cells that constitutively express -galactosidase into non-Rosa26 cells in an air-liquid interface cell culture model; 1.7% of the cells formed colonies of varying size, and, on average, 0.1% of the cells formed large colonies. Thus only a small subset of cells displayed progenitorial capacity suggestive of stem or early transient amplifying cells. Prior studies identified cells with high keratin 5 (K5) promoter activity in specific niches in the mouse trachea and these cells corresponded to the location of bromodeoxyuridine label-retaining cells, thought to be stem cells (Borthwick DW, Shahbazian M, Todd KQ, Dorin JR, and Randell SH, Am J Respir Cell Mol Biol: 24: 662-670, 2001). To explore the hypothesis that stem cells were present in the K5-expressing compartment, we created transgenic mice in which enhanced green fluorescent protein (EGFP) was driven by the K5 promoter. These mice expressed EGFP in most basal cells of the body including a subset of tracheal basal cells apparently located in positions similar to previously identified stem cell niches. Flow cytometrically purified EGFP-positive cells had an overall colony-forming efficiency 4.5-fold greater than EGFP-negative cells, but the ability to generate large colonies was 12-fold greater. Thus adult mouse tracheal epithelial cells with progenitorial capacity sufficient to generate large colonies reside in the basal cell compartment. These studies are a first step toward purification and characterization of airway epithelial stem cells.
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Affiliation(s)
- Kelly G Schoch
- UNC CF Cente, CB 7248, Rm. 4011 Thurston-Bowles, Chapel Hill, NC 27599, USA.
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Liu Y, Lyle S, Yang Z, Cotsarelis G. Keratin 15 promoter targets putative epithelial stem cells in the hair follicle bulge. J Invest Dermatol 2004; 121:963-8. [PMID: 14708593 DOI: 10.1046/j.1523-1747.2003.12600.x] [Citation(s) in RCA: 308] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Putative epithelial stem cells in the hair follicle bulge are thought to play pivotal roles in the homeostasis, aging, and carcinogenesis of the cutaneous epithelium. Elucidating the role of bulge cells in these processes has been hampered by the lack of gene promoters that target this area with specificity. Here we describe the isolation of the mouse keratin 15 (K15) promoter and demonstrate its utility for preferentially targeting hair follicle bulge cells in adult K15/lacZ transgenic mice. We found that patterns of K15 expression and promoter activity changed with age and correlated with levels of differentiation within the cutaneous epithelium; less differentiated keratinocytes in the epidermis of the neonatal mouse and in the bulge area of the adult mouse preferentially expressed K15. These findings demonstrate the utility of the K15 promoter for targeting epithelial stem cells in the hair follicle bulge and set the stage for elucidating the role of bulge cells in skin biology.
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Affiliation(s)
- Yaping Liu
- Department of Dermatology, Kligman Laboratories, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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40
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Zenz R, Scheuch H, Martin P, Frank C, Eferl R, Kenner L, Sibilia M, Wagner EF. c-Jun regulates eyelid closure and skin tumor development through EGFR signaling. Dev Cell 2003; 4:879-89. [PMID: 12791272 DOI: 10.1016/s1534-5807(03)00161-8] [Citation(s) in RCA: 212] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To investigate the function of c-Jun during skin development and skin tumor formation, we conditionally inactivated c-jun in the epidermis. Mice lacking c-jun in keratinocytes (c-jun(Deltaep)) develop normal skin but express reduced levels of EGFR in the eyelids, leading to open eyes at birth, as observed in EGFR null mice. Primary keratinocytes from c-jun(Deltaep) mice proliferate poorly, show increased differentiation, and form prominent cortical actin bundles, most likely because of decreased expression of EGFR and its ligand HB-EGF. In the absence of c-Jun, tumor-prone K5-SOS-F transgenic mice develop smaller papillomas, with reduced expression of EGFR in basal keratinocytes. Thus, using three experimental systems, we show that EGFR and HB-EGF are regulated by c-Jun, which controls eyelid development, keratinocyte proliferation, and skin tumor formation.
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Affiliation(s)
- Rainer Zenz
- Research Institute of Molecular Pathology (IMP), A-1030, Vienna, Austria
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41
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Abstract
Tumour architecture mimics many of the features of normal tissues, with a cellular hierarchy that regulates the balance between cell renewal and cell death. Although many tumours contain cells with the characteristics of stem cells, the identity of the normal cells that acquire the first genetic hits leading to initiation of carcinogenesis has remained elusive. Identification of the primary cell of origin of cancers and the mechanisms that influence cell-fate decisions will be crucial for the development of novel non-toxic therapies that influence tumour-cell behaviour.
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Affiliation(s)
- Jesus Perez-Losada
- UCSF Comprehensive Cancer Center, 2340 Sutter Street, San Francisco, California 94143, USA.
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42
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Watanabe Y, Tanaka R, Kobayashi H, Utoh R, Suzuki KI, Obara M, Yoshizato K. Metamorphosis-dependent transcriptional regulation of xak-c, a novel Xenopus type I keratin gene. Dev Dyn 2002; 225:561-70. [PMID: 12454932 DOI: 10.1002/dvdy.10196] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Anuran larvae transform their epidermis to the adult counterpart during metamorphosis. The major event of this process is the proliferation of larval epidermal basal cells and their differentiation into adult ones. The present study isolated novel type I keratin cDNA dubbed xak-c (Xenopus adult keratin-c) that was exclusively expressed in adult epidermal basal cells. The gene started its expression in the larval epidermis at the onset of metamorphosis. Thyroid hormone (TH) induced the precocious expression of the gene in the epidermis of premetamorphic tadpoles. To study the transcriptional regulation of this gene in relation to epidermal metamorphosis, a 2.8 kb 5'-flanking region of xak-c was cloned and its promoter activity was investigated. Gene constructs were made so as to contain the xak-c promoter region and gene of EGFP or luciferase as a reporter gene and were transfected into various types of cells, which revealed that the 5'-flanking region had an epidermal cell-specific transcriptional activity in both anurans and mammals. Larval skin tissues of Xenopus were transfected with the constructs and cultured in the presence and absence of TH, which showed that the promoter region is responsive to TH, although the region did not contain the consensus TH response element-like sequence. In sharp contrast, the promoter region did not respond to TH in the adult skin, clearly indicating that the cloned region contains specific sequences that respond to metamorphosis-dependent transcription factor(s).
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Affiliation(s)
- Yusuke Watanabe
- Developmental Biology Laboratory, Department of Biological Science, Graduate School of Science, Hiroshima University, Higashihiroshima, Hiroshima, Japan
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43
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Jang SI, Steinert PM. Loricrin expression in cultured human keratinocytes is controlled by a complex interplay between transcription factors of the Sp1, CREB, AP1, and AP2 families. J Biol Chem 2002; 277:42268-79. [PMID: 12200429 DOI: 10.1074/jbc.m205593200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The major protein component of the cornified cell envelope barrier structure of the epidermis is loricrin, and it is expressed late during terminal differentiation in epidermal keratinocytes. We have previously shown that an AP1 site located in the proximal promoter region (position -55) is essential for human loricrin promoter activity (Rossi, A., Jang, S-I., Ceci, R., Steinert, P. M., and Markova, N. G. (1998) J. Invest. Dermatol. 110, 34-40). In this study we show that its regulation requires complex cooperative and competitive interactions between multiple transcription factors in keratinocytes located in different compartments of the epidermis. We show that as few as 154 base pairs of 5'-upstream sequences from the cap site can direct the keratinocyte-specific expression in cultured keratinocytes. Mutation and DNA-protein analyses show that Sp1, c-Jun, an unidentified regulator, and the co-activator p300/CREB-binding protein up-regulate whereas Sp3, CREB-1/CREMalpha/ATF-1, Jun B, and an AP2-like protein (termed the keratinocyte-specific repressor-1 (KSR-1)) suppress loricrin promoter activity. We show that CREB protein can compete with c-Jun for the AP1 site and repress loricrin promoter activity. We show here that the protein kinase A pathway can activate loricrin expression by manipulation of the Sp1, Sp3, and KSR-1 levels in the nucleus. Thus, in undifferentiated cells, loricrin expression is suppressed by Jun B, Sp3, and KSR-1 proteins. But in advanced differentiated cells, levels of Sp3, KSR-1, and CREB proteins are lower; the unidentified regulator protein can bind; Sp1 and c-Jun are increased; and then p300/CBP is recruited. Together, these events allow loricrin transcription to proceed. Indeed, the synergistic effects of the Sp1, c-Jun, and p300 factors indicate that p300/CBP might act as bridge to form an active transcription complex.
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Affiliation(s)
- Shyh-Ing Jang
- Laboratory of Skin Biology, NIAMS, National Institutes of Health, Bethesda, Maryland 20892-8023, USA.
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44
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Guha U, Gomes WA, Kobayashi T, Pestell RG, Kessler JA. In vivo evidence that BMP signaling is necessary for apoptosis in the mouse limb. Dev Biol 2002; 249:108-20. [PMID: 12217322 DOI: 10.1006/dbio.2002.0752] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To determine the role of Bone morphogenetic protein (BMP) signaling in murine limb development in vivo, the keratin 14 promoter was used to drive expression of the BMP antagonist Noggin in transgenic mice. Phosphorylation and nuclear translocation of Smad1/5 were dramatically reduced in limbs of the transgenic animals, confirming the inhibition of BMP signaling. These mice developed extensive limb soft tissue syndactyly and postaxial polydactyly. Apoptosis in the developing limb necrotic zones was reduced with incomplete regression of the interdigital tissue. The postaxial extra digit is also consistent with a role for BMPs in regulating apoptosis. Furthermore, there was persistent expression of Fgf8, suggesting a delay in the regression of the AER. However, Msx1 and Msx2 expression was unchanged in these transgenic mice, implying that induction of these genes is not essential for mediating BMP-induced interdigital apoptosis in mice. These abnormalities were rescued by coexpressing BMP4 under the same promoter in double transgenic mice, suggesting that the limb abnormalities are a direct effect of inhibiting BMP signaling.
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Affiliation(s)
- Udayan Guha
- Department of Nueroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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45
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Abstract
The clinical implications of understanding epidermal stem cell biology abound. Thousands of burns victims across the world have benefited from early research into the proliferation of epidermal keratinocytes in vitro. Advances now indicate there are a number of stem cell repositories within the epidermis, two of which, the interfollicular epidermis and the bulge region of the hair follicle, may supply each other when damaged. This review details the progress made in the identification and characterisation of stem cells within the epidermis and discusses the molecules involved in the epidermal stem cell's choice of fate. Finally, the skin, like bone marrow, could be a readily accessible source of stem cells for therapeutic intervention and evidence of skin stem cell plasticity is highlighted.
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Affiliation(s)
- Sam M Janes
- Imperial Cancer Research Fund, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
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46
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Mahony D, Karunaratne S, Rothnagel JA. Improved detection of lacZ reporter gene expression in transgenic epithelia by immunofluorescence microscopy. Exp Dermatol 2002; 11:153-8. [PMID: 11994142 DOI: 10.1034/j.1600-0625.2002.110207.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The bacterial lacZ gene is commonly used as a reporter for the in vivo analysis of gene regulation in transgenic mice. However, several laboratories have reported poor detection of beta-galactosidase (the lacZ gene product) using histochemical techniques, particularly in skin. Here we report the difficulties we encountered in assessing lacZ expression in transgenic keratinocytes using classic X-gal histochemical protocols in tissues shown to express the transgene by mRNA in situ hybridization. We found that lacZ reporter gene expression could be reliably detected in frozen tissue sections by immunofluorescence analysis using a beta-galactosidase-specific antibody. Moreover, we were able to localize both transgene and endogenous gene products simultaneously using double-label immunofluorescence. Our results suggest that antibody detection of beta-galactosidase should be used to verify other assays of lacZ expression, particularly where low expression levels are suspected or patchy expression is observed.
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Affiliation(s)
- Donna Mahony
- Department of Biochemistry and Molecular Biology and the Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD, Australia
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47
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Carraresi L, Tripodi SA, Mulder LC, Bertini S, Nuti S, Schuerfeld K, Cintorino M, Bensi G, Rossini M, Mora M. Thymic hyperplasia and lung carcinomas in a line of mice transgenic for keratin 5-driven HPV16 E6/E7 oncogenes. Oncogene 2001; 20:8148-53. [PMID: 11781829 DOI: 10.1038/sj.onc.1205007] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2001] [Revised: 09/26/2001] [Accepted: 10/01/2001] [Indexed: 01/13/2023]
Abstract
Human Papillomavirus type 16 (HPV-16) is the cause of both benign lesions and ano-genital cancers. In HPV-associated cancers the transforming properties of the expressed viral E6 and E7 proteins have been revealed by a number of different assays. We have generated transgenic mice expressing HPV-16 E6/E7 genes under the control of the murine keratin 5 gene promoter, which should confer cell-type specific expression in the basal cells of squamous stratified epithelia. Transgenic mice developed thymic hyperplasia and lung neoplasia with 100% frequency, the thymus showing a size increase at 2 months and reaching the maximum dimension at 6 months, when lung carcinomas appeared. After this time the size of hyperplastic thymi decreased, while malignant formations invaded the mediastinal area. Hepatic metastasis could be also observed in some of the animals at the autopsy and death invariably occurred around 10-11 months of age.
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Affiliation(s)
- L Carraresi
- Department of Physiopathology and Experimental Medicine, University of Siena, Via Aldo Moro, 53100 Siena, Italy
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Borthwick DW, Shahbazian M, Krantz QT, Dorin JR, Randell SH. Evidence for stem-cell niches in the tracheal epithelium. Am J Respir Cell Mol Biol 2001; 24:662-70. [PMID: 11415930 DOI: 10.1165/ajrcmb.24.6.4217] [Citation(s) in RCA: 320] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
It is generally important to elucidate airway epithelial cell lineages and to identify multipotent progenitors as targets for gene therapy. Stem (S) cells are typically present in specialized compartments spatially proximal to their differentiated progeny, but an equivalent paradigm has not been demonstrated in the airway. We discovered a distinct population of cells displaying high levels of keratin expression in murine tracheal submucosal gland ducts, and tested the hypothesis that bromodeoxyuridine (BrdU) label-retaining cells (LRCs), thought to represent the S-cells, were present in this compartment. Mice received weekly epithelial damage by intratracheal detergent or SO(2) inhalation for 4 wk and received intraperitoneal injections of BrdU every 48 h during the injury and repair period. At 3 and 6 d after injury, BrdU-positive epithelial cells were noted along the entire tracheal length in both basal and lumenal cell positions. At later time points (20 and 95 d) LRCs were localized to gland ducts in the upper trachea and to systematically arrayed foci in the lower trachea, typically near the cartilage-intercartilage junction. LRCs were not pulmonary neuroendocrine cells. Heterotopic tracheal grafts after surface epithelial removal demonstrated reconstitution of a surface-like epithelium from gland remnants. These results suggest that airway epithelial S cells are localized to specific niches.
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Affiliation(s)
- D W Borthwick
- Medical Research Council Human Genetics Unit, Edinburgh, United Kingdom
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49
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Abstract
BACKGROUND Tissue-specific promoters are becoming increasingly important in light of their effects on gene expression in gene therapy experiments. The regulation of gene expression may be as important as the delivery of the gene itself. OBJECTIVES To determine the effects of the involucrin (INV), keratin 14 (K14) and cytomegalovirus (CMV) promoters on the expression of the reporter gene beta-galactosidase. METHODS In vivo, plasmid DNA was introduced to BALB/c mice by gene gun. Skin biopsies were taken after 24 h for histology and beta-galactosidase staining. In tissue culture cells, plasmid DNA was introduced by transient transfection to cell lines 293 (transformed primary human embryonal kidney cells), NIH 3T3 (immortalized mouse fibroblasts) and human keratinocytes. Reporter gene expression was assayed by histochemical staining and chemiluminescence. RESULTS The K14 and INV promoter constructs showed beta-galactosidase gene expression only in the epidermis, while the CMV promoter showed gene expression in both the dermis and epidermis. In cell culture, the INV and K14 promoter constructs demonstrated significant beta-galactosidase expression in human keratinocytes, but minimal expression in 293 and NIH 3T3 cell types. CMV promoter constructs demonstrated significant expression in all cell types. CONCLUSIONS Gene expression can be regulated by different promoters both in vivo and in cell culture. Based on the physiological expression of the different promoters, gene expression can be restricted to certain cell types, tissues and skin layers.
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Affiliation(s)
- M T Lin
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, 233 S 10th Street, Suite 450 BLSB, Philadelphia, PA 19107, USA
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50
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Mahony D, Karunaratne S, Cam G, Rothnagel JA. Analysis of mouse keratin 6a regulatory sequences in transgenic mice reveals constitutive, tissue-specific expression by a keratin 6a minigene. J Invest Dermatol 2000; 115:795-804. [PMID: 11069616 DOI: 10.1046/j.1523-1747.2000.00132.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The analysis of keratin 6 expression is complicated by the presence of multiple isoforms that are expressed constitutively in a number of internal stratified epithelia, in palmoplantar epidermis, and in the companion cell layer of the hair follicle. In addition, keratin 6 expression is inducible in interfollicular epidermis and the outer root sheath of the follicle, in response to wounding stimuli, phorbol esters, or retinoic acid. In order to establish the critical regions involved in the regulation of keratin 6a (the dominant isoform in mice), we generated transgenic mice with two different-sized mouse keratin 6a constructs containing either 1.3 kb or 0.12 kb of 5' flanking sequence linked to the lacZ reporter gene. Both constructs also contained the first intron and the 3' flanking sequence of mouse keratin 6a. Ectopic expression of either transgene was not observed. Double-label immunofluorescence analyses demonstrated expression of the reporter gene in keratin 6 expressing tissues, including the hair follicle, tongue, footpad, and nail bed, showing that both transgenes retained keratinocyte-specific expression. Quantitative analysis of beta-galactosidase activity verified that both the 1.3 and 0.12 kb keratin 6a promoter constructs produced similar levels of the reporter. Notably, both constructs were constitutively expressed in the outer root sheath and interfollicular epidermis in the absence of any activating stimulus, suggesting that they lack the regulatory elements that normally silence transcription in these cells. This study has revealed that a keratin 6a minigene contains critical cis elements that mediate tissue-specific expression and that the elements regulating keratin 6 induction lie distal to the 1.3 kb promoter region.
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Affiliation(s)
- D Mahony
- Department of Biochemistry and the Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
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