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Shaban MM, Elhefny RA, Hussein SH, Badr AA, Nour ZA. Role of telomerase expression in interstitial lung diseases. THE EGYPTIAN JOURNAL OF BRONCHOLOGY 2019. [DOI: 10.4103/ejb.ejb_71_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Møller P, Wils RS, Jensen DM, Andersen MHG, Roursgaard M. Telomere dynamics and cellular senescence: an emerging field in environmental and occupational toxicology. Crit Rev Toxicol 2018; 48:761-788. [DOI: 10.1080/10408444.2018.1538201] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Peter Møller
- Department of Public Health, Section of Environmental Health, University of Copenhagen, Copenhagen, Denmark
| | - Regitze Sølling Wils
- Department of Public Health, Section of Environmental Health, University of Copenhagen, Copenhagen, Denmark
| | - Ditte Marie Jensen
- Department of Public Health, Section of Environmental Health, University of Copenhagen, Copenhagen, Denmark
| | | | - Martin Roursgaard
- Department of Public Health, Section of Environmental Health, University of Copenhagen, Copenhagen, Denmark
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Shoeb M, Joseph P, Kodali V, Mustafa G, Farris BY, Umbright C, Roberts JR, Erdely A, Antonini JM. Silica inhalation altered telomere length and gene expression of telomere regulatory proteins in lung tissue of rats. Sci Rep 2017; 7:17284. [PMID: 29230030 PMCID: PMC5725592 DOI: 10.1038/s41598-017-17645-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 11/28/2017] [Indexed: 12/27/2022] Open
Abstract
Exposure to silica can cause lung fibrosis and cancer. Identification of molecular targets is important for the intervention and/or prevention of silica-induced lung diseases. Telomeres consist of tandem repeats of DNA sequences at the end of chromosomes, preventing chromosomal fusion and degradation. Regulator of telomere length-1 (RTEL1) and telomerase reverse transcriptase (TERT), genes involved in telomere regulation and function, play important roles in maintaining telomere integrity and length. The goal of this study was to assess the effect of silica inhalation on telomere length and the regulation of RTEL1 and TERT. Lung tissues and blood samples were collected from rats at 4, 32, and 44 wk after exposure to 15 mg/m3 of silica × 6 h/d × 5 d. Controls were exposed to air. At all-time points, RTEL1 expression was significantly decreased in lung tissue of the silica-exposed animals compared to controls. Also, significant increases in telomere length and TERT were observed in the silica group at 4 and 32 wk. Telomere length, RTEL1 and TERT expression may serve as potential biomarkers related to silica exposure and may offer insight into the molecular mechanism of silica-induced lung disease and tumorigeneses.
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Affiliation(s)
- Mohammad Shoeb
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA.
| | - Pius Joseph
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Vamsi Kodali
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Gul Mustafa
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Breanne Y Farris
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Christina Umbright
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Jenny R Roberts
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Aaron Erdely
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - James M Antonini
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
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Tashiro J, Rubio GA, Limper AH, Williams K, Elliot SJ, Ninou I, Aidinis V, Tzouvelekis A, Glassberg MK. Exploring Animal Models That Resemble Idiopathic Pulmonary Fibrosis. Front Med (Lausanne) 2017; 4:118. [PMID: 28804709 PMCID: PMC5532376 DOI: 10.3389/fmed.2017.00118] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/11/2017] [Indexed: 02/03/2023] Open
Abstract
Large multicenter clinical trials have led to two recently approved drugs for patients with idiopathic pulmonary fibrosis (IPF); yet, both of these therapies only slow disease progression and do not provide a definitive cure. Traditionally, preclinical trials have utilized mouse models of bleomycin (BLM)-induced pulmonary fibrosis—though several limitations prevent direct translation to human IPF. Spontaneous pulmonary fibrosis occurs in other animal species, including dogs, horses, donkeys, and cats. While the fibrotic lungs of these animals share many characteristics with lungs of patients with IPF, current veterinary classifications of fibrotic lung disease are not entirely equivalent. Additional studies that profile these examples of spontaneous fibroses in animals for similarities to human IPF should prove useful for both human and animal investigators. In the meantime, studies of BLM-induced fibrosis in aged male mice remain the most clinically relevant model for preclinical study for human IPF. Addressing issues such as time course of treatment, animal size and characteristics, clinically irrelevant treatment endpoints, and reproducibility of therapeutic outcomes will improve the current status of preclinical studies. Elucidating the mechanisms responsible for the development of fibrosis and disrepair associated with aging through a collaborative approach between researchers will promote the development of models that more accurately represent the realm of interstitial lung diseases in humans.
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Affiliation(s)
- Jun Tashiro
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Gustavo A Rubio
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Andrew H Limper
- Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United States
| | - Kurt Williams
- Department Pathobiology and Diagnostic Investigations, College of Veterinary Medicine, Michigan State University, East Lansing, MI, United States
| | - Sharon J Elliot
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Ioanna Ninou
- Division of Immunology, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | - Vassilis Aidinis
- Division of Immunology, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | - Argyrios Tzouvelekis
- Division of Immunology, Biomedical Sciences Research Center "Alexander Fleming", Athens, Greece
| | - Marilyn K Glassberg
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, United States.,Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
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Telomere Damage Response and Low-Grade Inflammation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1024:213-224. [PMID: 28921472 DOI: 10.1007/978-981-10-5987-2_10] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Telomeres at the ends of chromosomes safeguard genome integrity and stability in human nucleated cells. However, telomere repeats shed off during cell proliferation and other stress responses. Our recent studies show that telomere attrition induces not only epithelial stem cell senescence but also low-grade inflammation in the lungs. The senescence-associated low-grade inflammation (SALI) is characteristic of alveolar stem cell replicative senescence, increased proinflammatory and anti-inflammatory cytokines, infiltrated immune cells, and spillover effects. To date, the mechanisms underlying SALI remain unclear. Investigations demonstrate that senescent epithelial stem cells with telomere erosion are not the source of secreted cytokines, containing no significant increase in expression of the genes coding for increased cytokines, suggesting an alternative senescence-associated secretory phenotype (A-SASP). Given that telomere loss results in significant alterations in the genomes and accumulations of the cleaved telomeric DNA in the cells and milieu externe, we conclude that telomere position effects (TPEs) on gene expression and damage-associated molecular patterns (DAMPs) in antigen presentation are involved in A-SASP and SALI in response to telomere damage in mammals.
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6
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Liu T, Yu H, Ding L, Wu Z, Gonzalez De Los Santos F, Liu J, Ullenbruch M, Hu B, Martins V, Phan SH. Conditional Knockout of Telomerase Reverse Transcriptase in Mesenchymal Cells Impairs Mouse Pulmonary Fibrosis. PLoS One 2015; 10:e0142547. [PMID: 26555817 PMCID: PMC4640706 DOI: 10.1371/journal.pone.0142547] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 10/25/2015] [Indexed: 12/31/2022] Open
Abstract
Telomerase is typically expressed in cellular populations capable of extended replication, such as germ cells, tumor cells, and stem cells, but is also induced in tissue injury, repair and fibrosis. Its catalytic component, telomerase reverse transcriptase (TERT) is induced in lung fibroblasts from patients with fibrotic interstitial lung disease and in rodents with bleomycin-induced pulmonary fibrosis. To evaluate the fibroblast specific role of TERT in pulmonary fibrosis, transgenic mice bearing a floxed TERT allele were generated, and then crossed with an inducible collagen α2(I)-Cre mouse line to generate fibroblast specific TERT conditional knockout mice. TERT-specific deficiency in mesenchymal cells caused attenuation of pulmonary fibrosis as manifested by reduced lung hydroxyproline content, type I collagen and α-smooth muscle actin mRNA levels. The TERT-deficient mouse lung fibroblasts displayed decreased cell proliferative capacity and higher susceptibility to induced apoptosis compared with control cells. Additionally TERT deficiency was associated with heightened α-smooth muscle actin expression indicative of myofibroblast differentiation. However the impairment of cell proliferation and increased susceptibility to apoptosis would cause a reduction in the myofibroblast progenitor population necessary to mount a successful myofibroblast-dependent fibrotic response. These findings identified a key role for TERT in fibroblast proliferation and survival essential for pulmonary fibrosis.
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Affiliation(s)
- Tianju Liu
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Hongfeng Yu
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Lin Ding
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Zhe Wu
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | | | - Jianhua Liu
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Matthew Ullenbruch
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Biao Hu
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Vanessa Martins
- Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Sem H. Phan
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
- * E-mail:
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Chen R, Zhang K, Chen H, Zhao X, Wang J, Li L, Cong Y, Ju Z, Xu D, Williams BRG, Jia J, Liu JP. Telomerase Deficiency Causes Alveolar Stem Cell Senescence-associated Low-grade Inflammation in Lungs. J Biol Chem 2015; 290:30813-29. [PMID: 26518879 DOI: 10.1074/jbc.m115.681619] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Indexed: 12/16/2022] Open
Abstract
Mutations of human telomerase RNA component (TERC) and telomerase reverse transcriptase (TERT) are associated with a subset of lung aging diseases, but the mechanisms by which TERC and TERT participate in lung diseases remain unclear. In this report, we show that knock-out (KO) of the mouse gene Terc or Tert causes pulmonary alveolar stem cell replicative senescence, epithelial impairment, formation of alveolar sacs, and characteristic inflammatory phenotype. Deficiency in TERC or TERT causes a remarkable elevation in various proinflammatory cytokines, including IL-1, IL-6, CXCL15 (human IL-8 homolog), IL-10, TNF-α, and monocyte chemotactic protein 1 (chemokine ligand 2 (CCL2)); decrease in TGF-β1 and TGFβRI receptor in the lungs; and spillover of IL-6 and CXCL15 into the bronchoalveolar lavage fluids. In addition to increased gene expressions of α-smooth muscle actin and collagen 1α1, suggesting myofibroblast differentiation, TERC deficiency also leads to marked cellular infiltrations of a mononuclear cell population positive for the leukocyte common antigen CD45, low-affinity Fc receptor CD16/CD32, and pattern recognition receptor CD11b in the lungs. Our data demonstrate for the first time that telomerase deficiency triggers alveolar stem cell replicative senescence-associated low-grade inflammation, thereby driving pulmonary premature aging, alveolar sac formation, and fibrotic lesion.
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Affiliation(s)
- Ruping Chen
- From the Department of Microbiology/Key Laboratory for Experimental Teratology of Chinese Ministry of Education, School of Medicine, Shandong University, Jinan, Shandong Province 250012, China, the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China
| | - Kexiong Zhang
- the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China
| | - Hao Chen
- the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China
| | - Xiaoyin Zhao
- the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China
| | - Jianqiu Wang
- the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China
| | - Li Li
- the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China
| | - Yusheng Cong
- the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China
| | - Zhenyu Ju
- the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China
| | - Dakang Xu
- the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China, the Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia, the Department of Molecular and Translational Science, Faculty of Medicine, Monash University, Clayton, Victoria 3168, Australia, and
| | - Bryan R G Williams
- the Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia, the Department of Molecular and Translational Science, Faculty of Medicine, Monash University, Clayton, Victoria 3168, Australia, and
| | - Jihui Jia
- From the Department of Microbiology/Key Laboratory for Experimental Teratology of Chinese Ministry of Education, School of Medicine, Shandong University, Jinan, Shandong Province 250012, China
| | - Jun-Ping Liu
- From the Department of Microbiology/Key Laboratory for Experimental Teratology of Chinese Ministry of Education, School of Medicine, Shandong University, Jinan, Shandong Province 250012, China, the Institute of Aging Research, Hangzhou Normal University, School of Medicine, Hangzhou, Zhejiang Province 311121, China, the Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia, the Department of Molecular and Translational Science, Faculty of Medicine, Monash University, Clayton, Victoria 3168, Australia, and the Department of Immunology, Faculty of Medicine, Central Clinical School, Monash University, Prahran, Victoria 3018, Australia
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Liu T, Ullenbruch M, Young Choi Y, Yu H, Ding L, Xaubet A, Pereda J, Feghali-Bostwick CA, Bitterman PB, Henke CA, Pardo A, Selman M, Phan SH. Telomerase and telomere length in pulmonary fibrosis. Am J Respir Cell Mol Biol 2013; 49:260-8. [PMID: 23526226 DOI: 10.1165/rcmb.2012-0514oc] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In addition to its expression in stem cells and many cancers, telomerase activity is transiently induced in murine bleomycin (BLM)-induced pulmonary fibrosis with increased levels of telomerase transcriptase (TERT) expression, which is essential for fibrosis. To extend these observations to human chronic fibrotic lung disease, we investigated the expression of telomerase activity in lung fibroblasts from patients with interstitial lung diseases (ILDs), including idiopathic pulmonary fibrosis (IPF). The results showed that telomerase activity was induced in more than 66% of IPF lung fibroblast samples, in comparison with less than 29% from control samples, some of which were obtained from lung cancer resections. Less than 4% of the human IPF lung fibroblast samples exhibited shortened telomeres, whereas less than 6% of peripheral blood leukocyte samples from patients with IPF or hypersensitivity pneumonitis demonstrated shortened telomeres. Moreover, shortened telomeres in late-generation telomerase RNA component knockout mice did not exert a significant effect on BLM-induced pulmonary fibrosis. In contrast, TERT knockout mice exhibited deficient fibrosis that was independent of telomere length. Finally, TERT expression was up-regulated by a histone deacetylase inhibitor, while the induction of TERT in lung fibroblasts was associated with the binding of acetylated histone H3K9 to the TERT promoter region. These findings indicate that significant telomerase induction was evident in fibroblasts from fibrotic murine lungs and a majority of IPF lung samples, whereas telomere shortening was not a common finding in the human blood and lung fibroblast samples. Notably, the animal studies indicated that the pathogenesis of pulmonary fibrosis was independent of telomere length.
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Affiliation(s)
- Tianju Liu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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Degryse AL, Xu XC, Newman JL, Mitchell DB, Tanjore H, Polosukhin VV, Jones BR, McMahon FB, Gleaves LA, Phillips JA, Cogan JD, Blackwell TS, Lawson WE. Telomerase deficiency does not alter bleomycin-induced fibrosis in mice. Exp Lung Res 2012; 38:124-34. [PMID: 22394286 DOI: 10.3109/01902148.2012.658148] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Idiopathic pulmonary fibrosis (IPF) is characterized by interstitial lung infiltrates, dyspnea, and progressive respiratory failure. Reports linking telomerase mutations to familial interstitial pneumonia (FIP) suggest that telomerase activity and telomere length maintenance are important in disease pathogenesis. To investigate the role of telomerase in lung fibrotic remodeling, intratracheal bleomycin was administered to mice deficient in telomerase reverse transcriptase (TERT) or telomerase RNA component (TERC) and to wild-type controls. TERT-deficient and TERC-deficient mice were interbred to the F6 and F4 generation, respectively, when they developed skin manifestations and infertility. Fibrosis was scored using a semiquantitative scale and total lung collagen was measured using a hydroxyprolinemicroplate assay. Telomere lengths were measured in peripheral blood leukocytes and isolated type II alveolar epithelial cells (AECs). Telomerase activity in type II AECs was measured using a real-time polymerase chain reaction (PCR)-based system. Following bleomycin, TERT-deficient and TERC-deficient mice developed an equivalent inflammatory response and similar lung fibrosis (by scoring of lung sections and total lung collagen content) compared to controls, a pattern seen in both early (F1) and later (F6 TERT and F4 TERC) generations. Telomere lengths were reduced in peripheral blood leukocytes and isolated type II AECs from F6 TERT-deficient and F4 TERC-deficient mice compared to controls. Telomerase deficiency in a murine model leads to telomere shortening, but does not predispose to enhanced bleomycin-induced lung fibrosis. Additional genetic or environmental factors may be necessary for development of fibrosis in the presence of telomerase deficiency.
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Affiliation(s)
- Amber L Degryse
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2650, USA
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10
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Giuliano M, Stellavato A, Cammarota M, Lamberti M, Miraglia N, Sannolo N, De Rosa M. Effects of low concentrations of benzene on human lung cells in vitro. Toxicol Lett 2009; 188:130-6. [DOI: 10.1016/j.toxlet.2009.03.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 03/20/2009] [Accepted: 03/20/2009] [Indexed: 12/01/2022]
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11
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Dolgachev VA, Ullenbruch MR, Lukacs NW, Phan SH. Role of stem cell factor and bone marrow-derived fibroblasts in airway remodeling. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:390-400. [PMID: 19147822 DOI: 10.2353/ajpath.2009.080513] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent evidence suggests that bone marrow-derived fibroblasts are involved in airway remodeling in asthma, but the role and mechanism of recruitment of these fibroblasts remains unclear. Stem cell factor (SCF), a key factor in the propagation of hematopoietic stem cells, is important in the process of airway remodeling as well. To test the hypothesis that SCF is involved in the recruitment and differentiation of bone marrow-derived progenitor cells, GFP-bone marrow chimeric mice were created. These mice were then sensitized and chronically challenged with cockroach antigen to induce chronic airway disease. Fluorescence microscopy revealed an influx of significant numbers of GFP-expressing fibroblasts in the airways of these mice, which was confirmed by flow cytometric analysis of cells co-expressing both GFP and collagen I. These cells preferentially expressed c-kit, interleukin-31 receptor, and telomerase reverse transcriptase when compared with control lung-derived fibroblasts. Interestingly, SCF stimulated interleukin-31 receptor expression in bone marrow cells, whereas interleukin-31 strongly induced telomerase reverse transcriptase expression in fibroblasts. Treatment with neutralizing antibodies to SCF significantly reduced airway remodeling and suppressed the recruitment of these bone marrow-derived cells to the lung. Thus SCF in conjunction with interleukin-31 may play a significant role in airway remodeling by promoting the recruitment of bone marrow-derived fibroblast precursors into the lung with the capacity to promote lung myofibroblast differentiation.
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Affiliation(s)
- Vladislav A Dolgachev
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA.
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12
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Bettendorf O, Schmidt H, Eltze E, Rody A, Herchenröder F, Jackisch C, Böcker W, Pfleiderer B. Quantitative measurement of telomerase activity and localization of its catalytic subunit (hTERT) in chronic inflammation of capsule formation around various model implants and in sarcomas in a rat model. J Biomed Mater Res A 2008; 85:646-50. [PMID: 17806120 DOI: 10.1002/jbm.a.31613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Telomerase is upregulated in some preneoplastic lesions and overexpressed in the majority of malignant tumors, but absent in most nonneoplastic somatic tissues. We analyzed telomerase activity using TRAP-assay in capsule tissues in a rat model with chronic inflammation and in tumor, and visualized the catalytic subunit of telomerase (hTERT) by immunhistochemistry. Significant elevated telomerase activity was found in tumor tissue compared with nonneoplastic tissue (p = 0.047). Cases with a strong inflammation in capsule tissue showed a specific telomerase activity. In these cases, there were no significant differences in telomerase activities compared with malignant tumor tissue. We demonstrate elevated telomerase activity and its diagnostic limits around model implants in a rat model, and visualize its expression not only in malignant tissue but also in inflammatory cells. So the quantitative measurement of telomerase activity should not be applied in general as a marker for malignancy in capsule tissue.
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Affiliation(s)
- O Bettendorf
- Institute of Pathology, University of Münster, Domagkstrasse 17, D-48149 Münster, Germany.
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Al-Haddad M, Wallace MB. Molecular diagnostics of non-small cell lung cancer using mediastinal lymph nodes sampled by endoscopic ultrasound-guided needle aspiration. Cytopathology 2006; 17:3-9. [PMID: 16417559 DOI: 10.1111/j.1365-2303.2006.00318.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Non-small cell lung cancer is a common cancer with significant mortality. Accurate and early staging of this cancer has a significant impact on outcome. Endoscopic ultrasound-guided fine needle aspiration of involved mediastinal lymph nodes is critical for staging. Several molecular markers have been identified recently in association with non-small cell carcinoma of the lung that are promising to make early detection of metastatic disease more reliable.
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Affiliation(s)
- M Al-Haddad
- Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, FL 32224, USA
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Liu T, Hu B, Chung MJ, Ullenbruch M, Jin H, Phan SH. Telomerase regulation of myofibroblast differentiation. Am J Respir Cell Mol Biol 2006; 34:625-33. [PMID: 16424384 PMCID: PMC2644224 DOI: 10.1165/rcmb.2005-0252oc] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Telomerase activity, which has wide expression in cancerous cells, is induced in lung proliferating fibroblasts. It is preferentially expressed in fibroblasts versus myofibroblasts. It is unknown whether regulation of telomerase expression is related to the process of fibroblast differentiation into myofibroblasts. The objective of this study was to clarify such a potential link between telomerase expression and myofibroblast differentiation. Telomerase inhibitor, 3'-azido-2',3'-dideoxythymidine, or antisense oligonucleotide to the telomerase RNA component was used to inhibit the induced fibroblast telomerase activity. The results showed that inhibition of induced telomerase increased alpha-smooth muscle actin expression, an indicator of myofibroblast differentiation. In contrast, induction of telomerase by basic fibroblast growth factor inhibited alpha-smooth muscle actin expression. These findings suggest that the loss of telomerase activity is closely associated with myofibroblast differentiation and possibly functions as a trigger for myofibroblast differentiation. Conversely, expression of telomerase suppresses myofibroblast differentiation.
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Affiliation(s)
- Tianju Liu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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15
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Wallace MB, Block M, Hoffman BJ, Hawes RH, Silvestri G, Reed CE, Mitas M, Ravenel J, Fraig M, Miller S, Jones ET, Boylan A. Detection of telomerase expression in mediastinal lymph nodes of patients with lung cancer. Am J Respir Crit Care Med 2003; 167:1670-5. [PMID: 12615614 DOI: 10.1164/rccm.200211-1297oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mediastinal lymph nodes are the most common site of tumor spread in non-small cell lung cancer (NSCLC). We hypothesized that micrometastatic disease could be detected by reverse transcription-polymerase chain reaction (RT-PCR) for expression of human telomerase reverse transcriptase (hTERT) in mediastinal lymph nodes and that a minimally invasive technique (endoscopic ultrasound-guided fine-needle aspiration [EUS-FNA]) is capable of sampling lymph nodes for PCR analysis without surgery. Mediastinal lymph nodes were sampled with EUS-FNA in patients with NSCLC and negative control subjects undergoing EUS for benign disease. Total RNA was harvested from samples, and RT-PCR was performed to detect telomerase gene expression. RNA was available from 87 of 100 lymph node aspirates from 39 patients with NSCLC and from 12 negative control patients. hTERT was expressed in 0 of 14 negative control lymph nodes in 18 of 57 pathologically negative lymph nodes from cancer patients and in 10 of 16 pathologically positive lymph nodes (p < 0.05). Five of 18 (28%) patients with no pathologically evident mediastinal disease expressed telomerase in at least one lymph node. Minimally invasive EUS-FNA with RT-PCR is capable of detecting expression of cancer specific mRNA in lymph nodes. Approximately one-third of pathologically negative mediastinal lymph nodes in NSCLC patients express hTERT mRNA. The clinical significance of this observation is yet to be determined.
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MESH Headings
- Adenocarcinoma/diagnostic imaging
- Adenocarcinoma/enzymology
- Adenocarcinoma/pathology
- Adult
- Biopsy, Needle/methods
- Carcinoma, Large Cell/diagnostic imaging
- Carcinoma, Large Cell/enzymology
- Carcinoma, Large Cell/pathology
- Carcinoma, Non-Small-Cell Lung/diagnostic imaging
- Carcinoma, Non-Small-Cell Lung/enzymology
- Carcinoma, Non-Small-Cell Lung/pathology
- Carcinoma, Squamous Cell/diagnostic imaging
- Carcinoma, Squamous Cell/enzymology
- Carcinoma, Squamous Cell/pathology
- Case-Control Studies
- DNA-Binding Proteins
- Endosonography/methods
- Feasibility Studies
- Gene Expression Regulation, Neoplastic/genetics
- Humans
- Lung Neoplasms/diagnostic imaging
- Lung Neoplasms/enzymology
- Lung Neoplasms/pathology
- Lymphatic Metastasis/diagnostic imaging
- Lymphatic Metastasis/pathology
- Mediastinoscopy/methods
- Mediastinum
- Neoplasm Staging/methods
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- RNA, Neoplasm/analysis
- RNA, Neoplasm/genetics
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Telomerase/analysis
- Telomerase/genetics
- Ultrasonography, Interventional/methods
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Affiliation(s)
- Michael B Wallace
- Division of Gastroenterology, Digestive Diseases Center, Medical University of South Carolina, Charleston, SC 29425, USA.
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Liu T, Nozaki Y, Phan SH. Regulation of telomerase activity in rat lung fibroblasts. Am J Respir Cell Mol Biol 2002; 26:534-40. [PMID: 11970904 DOI: 10.1165/ajrcmb.26.5.4668] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Fibroblasts from bleomycin-injured lungs express telomerase activity transiently during the period of active fibrosis, but the signal(s) responsible for its induction is (are) unknown. The objective of this study was to identify potential mediators capable of regulating telomerase activity induction in rat lung fibroblasts during pulmonary fibrosis. Lung fibroblasts from control (NRF) and bleomycin-treated (BRF) rats were isolated and treated in vitro with either basic fibroblast growth factor (bFGF) or interleukin-4 (IL-4). At selected time points after treatment, the cells were analyzed for telomerase activity, as well as telomerase reverse transcriptase (TERT) mRNA and protein by reverse transcriptase/polymerase chain reaction and Western blot, respectively. The results showed that bFGF could induce telomerase activity in NRF and stimulate further the induced activity in BRF. The bFGF effect was accompanied by increased TERT protein expression and a rapid but transient increase in TERT mRNA. In contrast, IL-4 inhibited the induced telomerase activity in BRF, which was accompanied by increased alpha-smooth muscle actin expression, an indicator of myofibroblast differentiation. These findings suggest that telomerase expression could be induced in rat lung fibroblasts by bFGF, but suppressed by IL-4, which promoted myofibroblast differentiation. The latter is consistent with the preferential expression of telomerase activity in fibroblasts relative to myofibroblasts.
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Affiliation(s)
- Tianju Liu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0602, USA
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Affiliation(s)
- Laura J Mauro
- Department of Animal Science, University of Minnesota, St. Paul, Minnesota 55108, USA
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