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Ko HS, Laiman V, Tsao PN, Chen CM, Chuang HC. Alteration in branching morphogenesis via YAP/TAZ in fibroblasts of fetal lungs in an LPS-induced inflammation model. Mol Med 2023; 29:16. [PMID: 36717779 PMCID: PMC9887856 DOI: 10.1186/s10020-023-00613-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Chorioamnionitis is a common cause of preterm birth and leads to serious complications in newborns. The objective of this study was to investigate the role of the Hippo signaling pathway in lung branching morphogenesis under a lipopolysaccharide (LPS)-induced inflammation model. MATERIALS AND METHODS IMR-90 cells and ex vivo fetal lungs were treated with 0, 10, 30, or 50 μg/ml LPS for 24 and 72 h. Supernatant levels of lactate dehydrogenase (LDH), interleukin (IL)-6, IL-8, Chemokine (C-X-C motif) ligand 1(CXCL1), branching and the surface area ratio, Yes-associated protein (YAP), transcription coactivator with PDZ-binding motif (TAZ), fibroblast growth factor 10 (FGF10), fibroblast growth factor receptor II (FGFR2), SRY-box transcription factor 2 (SOX2), SOX9, and sirtuin 1 (SIRT1) levels were examined. Differentially expressed genes in fetal lungs after LPS treatment were identified by RNA-sequencing. RESULTS LPS at 50 μg/ml increased IL-6 and IL-8 in IMR-90 cells and increased IL-6, CXCL1 and LDH in fetal lungs. The branching ratio significantly increased by LPS at 30 μg/ml compared to the control but the increased level had decreased by 50 μg/ml LPS exposure. Exposure to 50 μg/ml LPS increased phosphorylated (p)-YAP, p-YAP/YAP, and p-TAZ/TAZ in IMR-90 cells, whereas 50 μg/ml LPS decreased FGF10 and SOX2. Consistently, p-YAP/YAP and p-TAZ/TAZ were increased in fibronectin+ cells of fetal lungs. Moreover, results of RNA-sequencing in fetal lungs showed that SMAD, FGF, IκB phosphorylation, tissue remodeling and homeostasis was involved in branching morphogenesis following exposure to 50 μg/ml LPS. The p-SIRT1/SIRT1 ratio increased in IMR-90 cells by LPS treatment. CONCLUSIONS This study showed that regulation of the Hippo pathway in fibroblasts of fetal lungs was involved in branching morphogenesis under an inflammatory disease such as chorioamnionitis.
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Affiliation(s)
- Hung-Shuo Ko
- grid.412896.00000 0000 9337 0481School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Vincent Laiman
- grid.412896.00000 0000 9337 0481International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan ,grid.8570.a0000 0001 2152 4506Department of Anatomical Pathology, Faculty of Medicine, Public Health, and Nursing, Dr. Sardjito Hospital, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Po-Nien Tsao
- grid.412094.a0000 0004 0572 7815Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Chung-Ming Chen
- grid.412897.10000 0004 0639 0994Department of Pediatrics, Taipei Medical University Hospital, Taipei, Taiwan ,grid.412896.00000 0000 9337 0481Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Hsiao-Chi Chuang
- grid.412896.00000 0000 9337 0481School of Respiratory Therapy, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 11031 Taiwan ,grid.412896.00000 0000 9337 0481Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan ,grid.412896.00000 0000 9337 0481Cell Physiology and Molecular Image Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan ,grid.412896.00000 0000 9337 0481Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan ,grid.7445.20000 0001 2113 8111National Heart & Lung Institute, Imperial College London, London, UK
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Pakravan K, Razmara E, Mahmud Hussen B, Sattarikia F, Sadeghizadeh M, Babashah S. SMAD4 contributes to chondrocyte and osteocyte development. J Cell Mol Med 2022; 26:1-15. [PMID: 34841647 PMCID: PMC8742202 DOI: 10.1111/jcmm.17080] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/25/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022] Open
Abstract
Different cellular and molecular mechanisms contribute to chondrocyte and osteocyte development. Although vital roles of the mothers against decapentaplegic homolog 4 (also called 'SMAD4') have been discussed in different cancers and stem cell-related studies, there are a few reviews summarizing the roles of this protein in the skeletal development and bone homeostasis. In order to fill this gap, we discuss the critical roles of SMAD4 in the skeletal development. To this end, we review the different signalling pathways and also how SMAD4 defines stem cell features. We also elaborate how the epigenetic factors-ie DNA methylation, histone modifications and noncoding RNAs-make a contribution to the chondrocyte and osteocyte development. To better grasp the important roles of SMAD4 in the cartilage and bone development, we also review the genotype-phenotype correlation in animal models. This review helps us to understand the importance of the SMAD4 in the chondrocyte and bone development and the potential applications for therapeutic goals.
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Affiliation(s)
- Katayoon Pakravan
- Department of Molecular GeneticsFaculty of Biological SciencesTarbiat Modares UniversityTehranIran
| | - Ehsan Razmara
- Department of Medical GeneticsFaculty of Medical SciencesTarbiat Modares UniversityTehranIran
| | - Bashdar Mahmud Hussen
- Department of PharmacognosyCollege of PharmacyHawler Medical UniversityKurdistan RegionIraq
| | - Fatemeh Sattarikia
- Department of Molecular GeneticsFaculty of Biological SciencesTarbiat Modares UniversityTehranIran
| | - Majid Sadeghizadeh
- Department of Molecular GeneticsFaculty of Biological SciencesTarbiat Modares UniversityTehranIran
| | - Sadegh Babashah
- Department of Molecular GeneticsFaculty of Biological SciencesTarbiat Modares UniversityTehranIran
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Systematical Identification of the Protective Effect of Danhong Injection and BuChang NaoXinTong Capsules on Transcription Factors in Cerebral Ischemia Mice Brain. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2020:5879852. [PMID: 33414894 PMCID: PMC7755463 DOI: 10.1155/2020/5879852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 10/20/2020] [Accepted: 11/17/2020] [Indexed: 11/17/2022]
Abstract
Cerebral ischemia has led to a high rate of both disability and mortality with massive healthcare costs. Although transcriptional regulation is typically mediated by different combinations of TFs, a combined regulatory unit to synergistically activate transcription has remained unclear in cerebral ischemia, especially in different drug treatments. In this study, TFs alterations after 6 h cerebral ischemic injury and repair were performed by a concatenated tandem array of consensus transcription factor response elements (catTFREs), and vital TFs were obtained by TFs-target imbalanced network. Drug intervention used Danhong injection (DHI) and BNC (BuChang NaoXinTong Capsules), which has been widely prescribed in Chinese herb medicine for the treatment of cerebrovascular and cardiovascular diseases. There were 198 TFs identified after 6 h MCAO operation, and six TFs (Sox2, Smad3, FoxO1, Creb1, Egr,1 and Smad4) were considered as critical TFs in response to cerebral ischemia. Moreover, Smad3 was identified as a hub TF among six vital TFs, and the transcription activity of Smad3 was further verified. These 6 TFs were all reversed by DHI or BNC, indicating different medications may regulate different transcription factors through TF synergy. Moreover, validation results indicated that Smad3 was a putative target TF for DHI and BNC-mediated protection against cerebral ischemia. The observations of the present study provide a fresh understanding of biomolecules and possible new avenues for therapeutic interventions, in addition to the new intervention pattern for different treatments for ischemia stroke.
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Shen YQ, Bao ZD, Pan JJ, Mao XN, Cheng R, Zhou XG, Zhou XY, Yang Y. MicroRNA‑431 inhibits the expression of surfactant proteins through the BMP4/activin/TGF‑β signaling pathway by targeting SMAD4. Int J Mol Med 2020; 45:1571-1582. [PMID: 32323744 DOI: 10.3892/ijmm.2020.4511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/13/2020] [Indexed: 11/06/2022] Open
Abstract
The synthesis and secretion of surfactant proteins (SPs) is an important sign of lung maturation. Furthermore, the morbidity of lung developmental diseases, including respiratory distress syndrome and bronchopulmonary dysplasia which are mainly caused by immature lung development and lack of SPs, is increasing. As is well known, multiple microRNAs (miRs/miRNAs) are able to influence lung development via numerous different signaling pathways. However, few studies examine the association between the miRNAs and lung developmental diseases. A previous study has demonstrated that miR‑431 was significantly (F=33.49; P<0.001) downregulated in the lung tissues of Sprague‑Dawley rats at 3 time points, embryonic day 19, embryonic day 21 and postnatal day 3. The present study reported that the regulation of miR‑431 may influence the expression of SPs. Thus, the further potential mechanisms of miR‑431 in negatively regulating lung development were examined in the present study. Stable A549 cell lines overexpressing or knocking down SMAD family member 4 (SMAD4) transfected with miR‑431 overexpressed or knocked down, and their control groups were established. Subsequently, the expression of bone morphogenetic protein 4 (BMP4), SMAD4 and SPs (SP‑A, SP‑B and SP‑C) at the RNA and protein levels were validated respectively by reverse transcription quantitative PCR and western blotting. miR‑431 exhibited a decreased expression, while BMP4 and SPs exhibited increased expression at the mRNA and protein levels in the SMAD4 knockdown group. Meanwhile, the expression of SPs were reduced in the SMAD4‑knockdown group via overexpressing miR‑431 and increased in the SMAD4‑overexpression group via inhibiting miR‑431. The present results indicate that SMAD4 negatively regulates the expression of SPs, and that miR‑431 negatively regulates the expression of SPs through inhibiting the BMP4/activin/transforming growth factor‑β signaling pathway by targeting SMAD4.
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Affiliation(s)
- Yan-Qing Shen
- Department of Neonates, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Zhi-Dan Bao
- Department of Neonates, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Jing-Jing Pan
- Department of Pediatrics, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Xiao-Nan Mao
- Department of Neonates, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Rui Cheng
- Department of Neonates, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Xiao-Guang Zhou
- Department of Neonates, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Xiao-Yu Zhou
- Department of Neonates, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Yang Yang
- Department of Neonates, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
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Prenatal microRNA miR-200b Therapy Improves Nitrofen-induced Pulmonary Hypoplasia Associated With Congenital Diaphragmatic Hernia. Ann Surg 2019; 269:979-987. [DOI: 10.1097/sla.0000000000002595] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Bloise E, Ciarmela P, Dela Cruz C, Luisi S, Petraglia F, Reis FM. Activin A in Mammalian Physiology. Physiol Rev 2019; 99:739-780. [DOI: 10.1152/physrev.00002.2018] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Activins are dimeric glycoproteins belonging to the transforming growth factor beta superfamily and resulting from the assembly of two beta subunits, which may also be combined with alpha subunits to form inhibins. Activins were discovered in 1986 following the isolation of inhibins from porcine follicular fluid, and were characterized as ovarian hormones that stimulate follicle stimulating hormone (FSH) release by the pituitary gland. In particular, activin A was shown to be the isoform of greater physiological importance in humans. The current understanding of activin A surpasses the reproductive system and allows its classification as a hormone, a growth factor, and a cytokine. In more than 30 yr of intense research, activin A was localized in female and male reproductive organs but also in other organs and systems as diverse as the brain, liver, lung, bone, and gut. Moreover, its roles include embryonic differentiation, trophoblast invasion of the uterine wall in early pregnancy, and fetal/neonate brain protection in hypoxic conditions. It is now recognized that activin A overexpression may be either cytostatic or mitogenic, depending on the cell type, with important implications for tumor biology. Activin A also regulates bone formation and regeneration, enhances joint inflammation in rheumatoid arthritis, and triggers pathogenic mechanisms in the respiratory system. In this 30-yr review, we analyze the evidence for physiological roles of activin A and the potential use of activin agonists and antagonists as therapeutic agents.
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Affiliation(s)
- Enrrico Bloise
- Department of Morphology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Molecular and Developmental Medicine, Obstetrics and Gynecological Clinic, University of Siena, Siena, Italy; and Department of Biomedical, Experimental and Clinical Sciences, Division of Obstetrics and
| | - Pasquapina Ciarmela
- Department of Morphology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Molecular and Developmental Medicine, Obstetrics and Gynecological Clinic, University of Siena, Siena, Italy; and Department of Biomedical, Experimental and Clinical Sciences, Division of Obstetrics and
| | - Cynthia Dela Cruz
- Department of Morphology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Molecular and Developmental Medicine, Obstetrics and Gynecological Clinic, University of Siena, Siena, Italy; and Department of Biomedical, Experimental and Clinical Sciences, Division of Obstetrics and
| | - Stefano Luisi
- Department of Morphology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Molecular and Developmental Medicine, Obstetrics and Gynecological Clinic, University of Siena, Siena, Italy; and Department of Biomedical, Experimental and Clinical Sciences, Division of Obstetrics and
| | - Felice Petraglia
- Department of Morphology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Molecular and Developmental Medicine, Obstetrics and Gynecological Clinic, University of Siena, Siena, Italy; and Department of Biomedical, Experimental and Clinical Sciences, Division of Obstetrics and
| | - Fernando M. Reis
- Department of Morphology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Department of Molecular and Developmental Medicine, Obstetrics and Gynecological Clinic, University of Siena, Siena, Italy; and Department of Biomedical, Experimental and Clinical Sciences, Division of Obstetrics and
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Chanda D, Otoupalova E, Smith SR, Volckaert T, De Langhe SP, Thannickal VJ. Developmental pathways in the pathogenesis of lung fibrosis. Mol Aspects Med 2018; 65:56-69. [PMID: 30130563 DOI: 10.1016/j.mam.2018.08.004] [Citation(s) in RCA: 272] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 08/17/2018] [Indexed: 12/20/2022]
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive and terminal lung disease with no known cure. IPF is a disease of aging, with median age of diagnosis over 65 years. Median survival is between 3 and 5 years after diagnosis. IPF is characterized primarily by excessive deposition of extracellular matrix (ECM) proteins by activated lung fibroblasts and myofibroblasts, resulting in reduced gas exchange and impaired pulmonary function. Growing evidence supports the concept of a pro-fibrotic environment orchestrated by underlying factors such as genetic predisposition, chronic injury and aging, oxidative stress, and impaired regenerative responses may account for disease development and persistence. Currently, two FDA approved drugs have limited efficacy in the treatment of IPF. Many of the genes and gene networks associated with lung development are induced or activated in IPF. In this review, we analyze current knowledge in the field, gained from both basic and clinical research, to provide new insights into the disease process, and potential approaches to treatment of pulmonary fibrosis.
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Affiliation(s)
- Diptiman Chanda
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| | - Eva Otoupalova
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Samuel R Smith
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Thomas Volckaert
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Stijn P De Langhe
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Victor J Thannickal
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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TGF-β Family Signaling in Ductal Differentiation and Branching Morphogenesis. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a031997. [PMID: 28289061 DOI: 10.1101/cshperspect.a031997] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Epithelial cells contribute to the development of various vital organs by generating tubular and/or glandular architectures. The fully developed forms of ductal organs depend on processes of branching morphogenesis, whereby frequency, total number, and complexity of the branching tissue define the final architecture in the organ. Some ductal tissues, like the mammary gland during pregnancy and lactation, disintegrate and regenerate through periodic cycles. Differentiation of branched epithelia is driven by antagonistic actions of parallel growth factor systems that mediate epithelial-mesenchymal communication. Transforming growth factor-β (TGF-β) family members and their extracellular antagonists are prominently involved in both normal and disease-associated (e.g., malignant or fibrotic) ductal tissue patterning. Here, we discuss collective knowledge that permeates the roles of TGF-β family members in the control of the ductal tissues in the vertebrate body.
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Yang Y, Fu Q, Liu Y, Wang X, Dunham R, Liu S, Bao L, Zeng Q, Zhou T, Li N, Qin Z, Jiang C, Gao D, Liu Z. Comparative transcriptome analysis reveals conserved branching morphogenesis related genes involved in chamber formation of catfish swimbladder. Physiol Genomics 2017; 50:67-76. [PMID: 29167198 DOI: 10.1152/physiolgenomics.00089.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The swimbladder is an internal gas-filled organ in teleosts. Its major function is to regulate buoyancy. The swimbladder exhibits great variation in size, shape, and number of compartments or chambers among teleosts. However, genomic control of swimbladder variation is unknown. Channel catfish ( Ictalurus punctatus), blue catfish ( Ictalurus furcatus), and their F1 hybrids of female channel catfish × male blue catfish (C × B hybrid catfish) provide a good model in which to investigate the swimbladder morphology, because channel catfish possess a single-chambered swimbladder, whereas blue catfish possess a bichambered swimbladder; C × B hybrid catfish possess a bichambered swimbladder but with a significantly reduced posterior chamber. Here we determined the transcriptional profiles of swimbladder from channel catfish, blue catfish, and C × B hybrid catfish. We examined their transcriptomes at both the fingerling and adult stages. Through comparative transcriptome analysis, ~4,000 differentially expressed genes (DEGs) were identified. Among these DEGs, members of the Wnt signaling pathway ( wnt1, wnt2, nfatc1, rac2), Hedgehog signaling pathway ( shh), and growth factors ( fgf10, igf-1) were identified. As these genes were known to be important for branching morphogenesis of mammalian lung and of mammary glands, their association with budding of the posterior chamber primordium and progressive development of bichambered swimbladder in fish suggest that these branching morphogenesis-related genes and their functions in branching are evolutionarily conserved across a broad spectrum of species.
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Affiliation(s)
- Yujia Yang
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Qiang Fu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama.,Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, China
| | - Yang Liu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Xiaozhu Wang
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Rex Dunham
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Shikai Liu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Lisui Bao
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Qifan Zeng
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Tao Zhou
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Ning Li
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Zhenkui Qin
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Chen Jiang
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Dongya Gao
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University , Auburn, Alabama
| | - Zhanjiang Liu
- Department of Biology, Syracuse University , Syracuse, New York
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Whiting CV, Williams AM, Claesson MH, Bregenholt S, Reimann J, Bland PW. Transforming Growth Factor-β Messenger RNA and Protein in Murine Colitis. J Histochem Cytochem 2016; 49:727-38. [PMID: 11373319 DOI: 10.1177/002215540104900606] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Using a CD4+ T-cell-transplanted SCID mouse model of colitis, we have analyzed TGF-β transcription and translation in advanced disease. By in situ hybridization, the epithelium of both control and inflamed tissues transcribed TGF-β1 and TGF-β3 mRNAs, but both were expressed significantly farther along the crypt axis in disease. Control lamina propria cells transcribed little TGF-β1 or TGF-β3 mRNA, but in inflamed tissues many cells expressed mRNA for both isoforms. No TGF-β2 message was detected in either control or inflamed tissues. Immunohistochemistry for latent and active TGF-β1 showed that all cells produced perinuclear latent TGF-β1. The epithelial cell basal latent protein resulted in only low levels of subepithelial active protein, which co-localized with collagen IV and laminin in diseased and control tissue. Infiltrating cells expressed very low levels of active TGF-β. By ELISA, very low levels (0–69 pg/mg) of soluble total or active TGF-β were detected in hypotonic tissue lysates. TGF-β1 and TGF-β3 are produced by SCID mouse colon and transcription is increased in the colitis caused by transplantation of CD4+ T-cells, but this does not result in high levels of soluble active protein. Low levels of active TGF-β may be a factor contributing to unresolved inflammation.
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Affiliation(s)
- C V Whiting
- Department of Clinical Veterinary Science, University of Bristol, Bristol, United Kingdom.
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Wijayarathna R, de Kretser DM. Activins in reproductive biology and beyond. Hum Reprod Update 2016; 22:342-57. [PMID: 26884470 DOI: 10.1093/humupd/dmv058] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 11/20/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Activins are members of the pleiotrophic family of the transforming growth factor-beta (TGF-β) superfamily of cytokines, initially isolated for their capacity to induce the release of FSH from pituitary extracts. Subsequent research has demonstrated that activins are involved in multiple biological functions including the control of inflammation, fibrosis, developmental biology and tumourigenesis. This review summarizes the current knowledge on the roles of activin in reproductive and developmental biology. It also discusses interesting advances in the field of modulating the bioactivity of activins as a therapeutic target, which would undoubtedly be beneficial for patients with reproductive pathology. METHODS A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies in the English language which have contributed to the advancement of the field of activin biology, since its initial isolation in 1987 until July 2015. 'Activin', 'testis', 'ovary', 'embryonic development' and 'therapeutic targets' were used as the keywords in combination with other search phrases relevant to the topic of activin biology. RESULTS Activins, which are dimers of inhibin β subunits, act via a classical TGF-β signalling pathway. The bioactivity of activin is regulated by two endogenous inhibitors, inhibin and follistatin. Activin is a major regulator of testicular and ovarian development. In the ovary, activin A promotes oocyte maturation and regulates granulosa cell steroidogenesis. It is also essential in endometrial repair following menstruation, decidualization and maintaining pregnancy. Dysregulation of the activin-follistatin-inhibin system leads to disorders of female reproduction and pregnancy, including polycystic ovary syndrome, ectopic pregnancy, miscarriage, fetal growth restriction, gestational diabetes, pre-eclampsia and pre-term birth. Moreover, a rise in serum activin A, accompanied by elevated FSH, is characteristic of female reproductive aging. In the male, activin A is an autocrine and paracrine modulator of germ cell development and Sertoli cell proliferation. Disruption of normal activin signalling is characteristic of many tumours affecting reproductive organs, including endometrial carcinoma, cervical cancer, testicular and ovarian cancer as well as prostate cancer. While activin A and B aid the progression of many tumours of the reproductive organs, activin C acts as a tumour suppressor. Activins are important in embryonic induction, morphogenesis of branched glandular organs, development of limbs and nervous system, craniofacial and dental development and morphogenesis of the Wolffian duct. CONCLUSIONS The field of activin biology has advanced considerably since its initial discovery as an FSH stimulating agent. Now, activin is well known as a growth factor and cytokine that regulates many aspects of reproductive biology, developmental biology and also inflammation and immunological mechanisms. Current research provides evidence for novel roles of activins in maintaining the structure and function of reproductive and other organ systems. The fact that activin A is elevated both locally as well as systemically in major disorders of the reproductive system makes it an important biomarker. Given the established role of activin A as a pro-inflammatory and pro-fibrotic agent, studies of its involvement in disorders of reproduction resulting from these processes should be examined. Follistatin, as a key regulator of the biological actions of activin, should be evaluated as a therapeutic agent in conditions where activin A overexpression is established as a contributing factor.
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Affiliation(s)
- R Wijayarathna
- Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia Centre for Reproductive Health, Hudson Institute of Medical Research, 27-31, Wright Street, Clayton, VIC 3168, Australia
| | - D M de Kretser
- Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia Centre for Reproductive Health, Hudson Institute of Medical Research, 27-31, Wright Street, Clayton, VIC 3168, Australia
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12
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Inhibition of TGF-β signaling and decreased apoptosis in IUGR-associated lung disease in rats. PLoS One 2011; 6:e26371. [PMID: 22028866 PMCID: PMC3197638 DOI: 10.1371/journal.pone.0026371] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 09/25/2011] [Indexed: 01/04/2023] Open
Abstract
Intrauterine growth restriction is associated with impaired lung function in adulthood. It is unknown whether such impairment of lung function is linked to the transforming growth factor (TGF)-β system in the lung. Therefore, we investigated the effects of IUGR on lung function, expression of extracellular matrix (ECM) components and TGF-β signaling in rats. IUGR was induced in rats by isocaloric protein restriction during gestation. Lung function was assessed with direct plethysmography at postnatal day (P) 70. Pulmonary activity of the TGF-β system was determined at P1 and P70. TGF-β signaling was blocked in vitro using adenovirus-delivered Smad7. At P70, respiratory airway compliance was significantly impaired after IUGR. These changes were accompanied by decreased expression of TGF-β1 at P1 and P70 and a consistently dampened phosphorylation of Smad2 and Smad3. Furthermore, the mRNA expression levels of inhibitors of TGF-β signaling (Smad7 and Smurf2) were reduced, and the expression of TGF-β-regulated ECM components (e.g. collagen I) was decreased in the lungs of IUGR animals at P1; whereas elastin and tenascin N expression was significantly upregulated. In vitro inhibition of TGF-β signaling in NIH/3T3, MLE 12 and endothelial cells by adenovirus-delivered Smad7 demonstrated a direct effect on the expression of ECM components. Taken together, these data demonstrate a significant impact of IUGR on lung development and function and suggest that attenuated TGF-β signaling may contribute to the pathological processes of IUGR-associated lung disease.
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13
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Dunphy KA, Schneyer AL, Hagen MJ, Jerry DJ. The role of activin in mammary gland development and oncogenesis. J Mammary Gland Biol Neoplasia 2011; 16:117-26. [PMID: 21475961 DOI: 10.1007/s10911-011-9214-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 03/16/2011] [Indexed: 10/18/2022] Open
Abstract
TGFβ contributes to mammary gland development and has paradoxical roles in breast cancer because it has both tumor suppressor and tumor promoter activity. Another member of the TGFβ superfamily, activin, also has roles in the developing mammary gland, but these functions, and the role of activin in breast cancer, are not well characterized. TGFβ and activin share the same intracellular signaling pathways, but divergence in their signaling pathways are suggested. The purpose of this review is to compare the spatial and temporal expression of TGFβ and activin during mammary gland development, with consideration given to their functions during each developmental period. We also review the contributions of TGFβ and activin to breast cancer resistance and susceptibility. Finally, we consider the systemic contributions of activin in regulating obesity and diabetes; and the impact this regulation has on breast cancer. Elevated levels of activin in serum during pregnancy and its influence on pregnancy associated breast cancer are also considered. We conclude that evidence demonstrates that activin has tumor suppressing potential, without definitive indication of tumor promoting activity in the mammary gland, making it a good target for development of therapeutics.
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Affiliation(s)
- Karen A Dunphy
- Department of Veterinary and Animal Science, University of Massachusetts-Amherst, Amherst, MA, USA.
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14
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Follistatin-like 1 (Fstl1) is a bone morphogenetic protein (BMP) 4 signaling antagonist in controlling mouse lung development. Proc Natl Acad Sci U S A 2011; 108:7058-63. [PMID: 21482757 DOI: 10.1073/pnas.1007293108] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lung morphogenesis is a well orchestrated, tightly regulated process through several molecular pathways, including TGF-β/bone morphogenetic protein (BMP) signaling. Alteration of these signaling pathways leads to lung malformation. We investigated the role of Follistatin-like 1 (Fstl1), a secreted follistatin-module-containing glycoprotein, in lung development. Deletion of Fstl1 in mice led to postnatal lethality as a result of respiratory failure. Analysis of the mutant phenotype showed that Fstl1 is essential for tracheal cartilage formation and alveolar maturation. Deletion of the Fstl1 gene resulted in malformed tracheal rings manifested as discontinued rings and reduced ring number. Fstl1-deficient mice displayed septal hypercellularity and end-expiratory atelectasis, which were associated with impaired differentiation of distal alveolar epithelial cells and insufficient production of mature surfactant proteins. Mechanistically, Fstl1 interacted directly with BMP4, negatively regulated BMP4/Smad1/5/8 signaling, and inhibited BMP4-induced surfactant gene expression. Reducing BMP signaling activity by Noggin rescued pulmonary atelectasis of Fstl1-deficient mice. Therefore, we provide in vivo and in vitro evidence to demonstrate that Fstl1 modulates lung development and alveolar maturation, in part, through BMP4 signaling.
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15
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Perotti C, Wiedl T, Florin L, Reuter H, Moffat S, Silbermann M, Hahn M, Angel P, Shemanko CS. Characterization of mammary epithelial cell line HC11 using the NIA 15k gene array reveals potential regulators of the undifferentiated and differentiated phenotypes. Differentiation 2009; 78:269-82. [PMID: 19523745 DOI: 10.1016/j.diff.2009.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2009] [Revised: 04/30/2009] [Accepted: 05/20/2009] [Indexed: 12/11/2022]
Abstract
Differentiation of undifferentiated mammary epithelial stem and/or progenitor cells results in the production of luminal-ductal and myoepithelial cells in the young animal and upon pregnancy, the production of luminal alveolar cells. A few key regulators of differentiation have been identified, though it is not known yet how these proteins function together to achieve their well-orchestrated products. In an effort to identify regulators of early differentiation, we screened the NIA 15k gene array of 15,247 developmentally expressed genes using mouse mammary epithelial HC11 cells as a model of differentiation. We have confirmed a number of genes preferentially expressed in the undifferentiated cells (Lgals1, Ran, Jam-A and Bmpr1a) and in those induced to undergo differentiation (Id1, Nfkbiz, Trib1, Rps21, Ier3). Using antibodies to the proteins encoded by Lgals1, and Jam-A, we confirmed that their proteins levels were higher in the undifferentiated cells. Although the amounts of bone morphogenetic protein receptor-1A (BMPR1A) protein were present at all stages, we found the activity of its downstream signal transduction pathway, as measured by the presence of phosphorylated-SMAD1, -SMAD5, and -SMAD8, is elevated in undifferentiated cells and decreases in fully differentiated cells. This evidence supports that the BMPR1A pathway functions primarily in undifferentiated mammary epithelial cells. We have identified a number of genes, of known and unknown function, that are candidates for the maintenance of the undifferentiated phenotype and for early regulators of mammary alveolar cell differentiation.
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Affiliation(s)
- C Perotti
- Department of Biological Sciences, University of Calgary, 2500 University Drive, N.W. Calgary, AB, Canada T2N 1N4
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16
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Wu S, Kasisomayajula K, Peng J, Bancalari E. Inhibition of JNK enhances TGF-beta1-activated Smad2 signaling in mouse embryonic lung. Pediatr Res 2009; 65:381-6. [PMID: 19127219 DOI: 10.1203/pdr.0b013e3181991c67] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Smad2/3 pathway plays a key role in mediating TGF-beta1 inhibition of branching morphogenesis and induction of connective tissue growth factor (CTGF) expression in embryonic lungs. Because a number of cell-specific interactions have been described between TGF-beta1-driven Smad signaling and the c-Jun N-terminal kinase (JNK) pathway, we have investigated the effects of JNK inhibition on TGF-beta1 activation of Smad2, inhibition of branching, induction of CTGF expression, and apoptosis in mouse embryonic lung explants. Mouse embryonic day 12.5 (E12.5) lung explants were treated with TGF-beta1 in the presence or absence of a specific pharmacologic JNK inhibitor (SP600125) and a specific JNK peptide inhibitor (JNKI). We found that TGF-beta1 activated the JNK pathway by stimulating c-Jun phosphorylation, which was blocked by JNK inhibitors. Treatment with SP600125 stimulated Smad2 phosphorylation and enhanced TGF-beta1-induced Smad2 phosphorylation. Treatment with JNK inhibitors also decreased normal branching morphogenesis and induced CTGF expression as well as augmented TGF-beta1 inhibition of branching and induction of CTGF expression. Furthermore, JNK inhibition-induced apoptosis. Our results demonstrate that inhibition of the JNK pathway promotes TGF-beta1-driven Smad2 responses in lung branching morphogenesis. These data suggest that the JNK pathway may antagonize TGF-beta1 dependent Smad2 signaling during mouse embryonic lung development.
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Affiliation(s)
- Shu Wu
- Department of Pediatrics, University of Miami Miller School of Medicine, Miami, Florida 33101, USA.
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17
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Archambeault DR, Tomaszewski J, Joseph A, Hinton BT, Yao HHC. Epithelial-mesenchymal crosstalk in Wolffian duct and fetal testis cord development. Genesis 2009; 47:40-8. [PMID: 18979542 PMCID: PMC2877590 DOI: 10.1002/dvg.20453] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Interactions between adjacent epithelial and mesenchymal tissues represent a highly conserved mechanism in embryonic organogenesis. In particular, the ability of the mesenchyme to instruct cellular differentiation of the epithelium is a fundamental requirement for the morphogenesis of tubular structures such as those found in the kidneys, lungs, and the developing male reproductive system. Once the tubular structure has formed, it receives signals from the mesenchyme, which can control proliferation, patterning, and differentiation of the epithelium inside the tube. However, the epithelium is not a "silent partner" in this process, and epithelium-derived factors are often required for proper maintenance of the mesenchymal compartment. Although much emphasis has been placed on the characterization of mesenchymally-derived signals required for epithelial differentiation, it is important to note that epithelial-mesenchymal interactions are a two-way street wherein each compartment requires the presence of the other for proper tubule morphogenesis and function. In this review, we discuss epithelial-mesenchymal interactions in the processes of Wolffian duct and fetal testis cord development using the mouse as a model organism and propose inhibin beta A as a conserved mesenchyme-derived regulator in these two male-specific tubular structures.
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Affiliation(s)
- Denise R. Archambeault
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Illinois
| | - Jessica Tomaszewski
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Illinois
| | - Avenel Joseph
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Illinois
| | - Barry T. Hinton
- Department of Cell Biology, School of Medicine, University of Virginia, Charlottesville, Virginia
| | - Humphrey Hung-Chang Yao
- Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Illinois
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18
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Choi CW, Kim BI, Joung KE, Lee JA, Lee YK, Kim EK, Kim HS, Park JD, Choi JH. Decreased expression of transforming growth factor-beta1 in bronchoalveolar lavage cells of preterm infants with maternal chorioamnionitis. J Korean Med Sci 2008; 23:609-15. [PMID: 18756046 PMCID: PMC2526412 DOI: 10.3346/jkms.2008.23.4.609] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Maternal chorioamnionitis has been associated with abnormal lung development. We examined the effect of maternal chorioamnionitis on the expression of transforming growth factor-beta1 (TGF-beta1) in the lungs of preterm infants. A total of 63 preterm (<or=34 weeks) infants who were intubated in the delivery room were prospectively enrolled. Their placentas were examined for the presence of chorioamnionitis. Bronchoalveolar lavage (BAL) fluid and cells were obtained shortly after birth. TGF-beta1 was measured in BAL fluid and TGF-beta1 mRNA expression was determined by reverse transcription polymerase chain reaction (RT-PCR) in BAL cells. TGF-beta1 mRNA expression in BAL cells showed a positive correlation with gestational age (r=0.414, p=0.002). TGF-beta1 mRNA expression was significantly decreased in the presence of maternal chorioamnionitis (0.70+/-0.12 vs. 0.81+/-0.15, p=0.007). Adjustment for gestational age, birth weight, and delivery mode did not nullify the significance. TGF-beta1 mRNA expression was marginally significantly decreased in preterm infants who developed bronchopulmonary dysplasia (BPD) later (0.75+/-0.11 vs. 0.82+/-0.15, p=0.055). However, adjustment for gestational age, patent ductus arteriosus (PDA), and maternal chorioamnionitis nullified the significance. These results might be an indirect evidence that maternal chorioamnionitis may inhibit normal lung development of fetus.
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Affiliation(s)
- Chang Won Choi
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
| | - Beyong Il Kim
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
| | - Kyoung Eun Joung
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
| | - Jin-A Lee
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
| | - Yun Kyoung Lee
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
| | - Ee-Kyung Kim
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
| | - Han-Suk Kim
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
| | - June Dong Park
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
| | - Jung-Hwan Choi
- Department of Pediatrics, Seoul National University, College of Medicine, Seoul, Korea
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19
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Alejandre-Alcázar MA, Michiels-Corsten M, Vicencio AG, Reiss I, Ryu J, de Krijger RR, Haddad GG, Tibboel D, Seeger W, Eickelberg O, Morty RE. TGF-beta signaling is dynamically regulated during the alveolarization of rodent and human lungs. Dev Dyn 2008; 237:259-69. [PMID: 18095342 DOI: 10.1002/dvdy.21403] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Although transforming growth factor-beta (TGF-beta) signaling negatively regulates branching morphogenesis in early lung development, few studies to date have addressed the role of this family of growth factors during late lung development. We describe here that the expression, tissue localization, and activity of components of the TGF-beta signaling machinery are dynamically regulated during late lung development in the mouse and human. Pronounced changes in the expression and localization of the TGF-beta receptors Acvrl1, Tgfbr1, Tgfbr2, Tgfbr3, and endoglin, and the intracellular messengers Smad2, Smad3, Smad4, Smad6, and Smad7 were noted as mouse and human lungs progressed through the canalicular, saccular, and alveolar stages of development. TGF-beta signaling, assessed by phosphorylation of Smad2, was detected in the vascular and airway smooth muscle, as well as the alveolar and airway epithelium throughout late lung development. These data suggest that active TGF-beta signaling is required for normal late lung development.
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Affiliation(s)
- Miguel A Alejandre-Alcázar
- Department of Internal Medicine, University of Giessen Lung Center, Justus Liebig University, Giessen, Germany
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20
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Kinane TB. Lung development and implications for hypoplasia found in congenital diaphragmatic hernia. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2007; 145C:117-24. [PMID: 17436303 DOI: 10.1002/ajmg.c.30124] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Congenital diaphragmatic hernia (CDH) is associated with various degrees of pulmonary hypoplasia and severe persistent pulmonary hypertension in the newborn. These conditions have significant implications for the outcome for the patient. Defects in early lung development are likely to be central to the generation of hypoplasia. A number of mouse models with defects in pathways that are central to lung development were found to have CDH. Understanding all aspects of early lung development will provide fresh insight into the pathogenesis of CDH and its associated conditions.
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Affiliation(s)
- T Bernard Kinane
- Pediatric Pulmonary, Massachusetts General Hospital for Children, Boston, MA 02114, USA.
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21
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Abstract
The vertebrate lung consists of multiple cell types that are derived primarily from endodermal and mesodermal compartments of the early embryo. The process of pulmonary organogenesis requires the generation of precise signaling centers that are linked to transcriptional programs that, in turn, regulate cell numbers, differentiation, and behavior, as branching morphogenesis and alveolarization proceed. This review summarizes knowledge regarding the expression and proposed roles of transcription factors influencing lung formation and function with particular focus on knowledge derived from the study of the mouse. A group of transcription factors active in the endodermally derived cells of the developing lung tubules, including thyroid transcription factor-1 (TTF-1), beta-catenin, Forkhead orthologs (FOX), GATA, SOX, and ETS family members are required for normal lung morphogenesis and function. In contrast, a group of distinct proteins, including FOXF1, POD1, GLI, and HOX family members, play important roles in the developing lung mesenchyme, from which pulmonary vessels and bronchial smooth muscle develop. Lung formation is dependent on reciprocal signaling among cells of both endodermal and mesenchymal compartments that instruct transcriptional processes mediating lung formation and adaptation to breathing after birth.
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Affiliation(s)
- Yutaka Maeda
- Division of Pulmonary Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center and The University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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22
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Wu S, Peng J, Duncan MR, Kasisomayajula K, Grotendorst G, Bancalari E. ALK-5 mediates endogenous and TGF-beta1-induced expression of connective tissue growth factor in embryonic lung. Am J Respir Cell Mol Biol 2006; 36:552-61. [PMID: 17197570 PMCID: PMC1899336 DOI: 10.1165/rcmb.2006-0320oc] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Transforming growth factor-beta1 (TGF-beta1) has been implicated as a major negative regulator of lung branching morphogenesis. Since connective tissue growth factor (CTGF) is a downstream mediator of TGF-beta1 effects on mesenchymal cells, we hypothesized that TGF-beta1 induces CTGF expression in mouse embryonic lung explants and that CTGF mediates TGF-beta1 inhibition of branching morphogenesis. We show that addition of TGF-beta1 to the serum-free medium of embryonic day (E)12.5 lung explant cultures inhibited branching morphogenesis and induced CTGF mRNA expression in time- and dose-dependent manners. In contrast to basal endogenous CTGF protein, which was exclusively localized in the distal airway epithelium, TGF-beta1-induced CTGF protein was localized in both the epithelium and the mesenchyme. Addition of exogenous CTGF to culture medium directly inhibited branching morphogenesis. To identify the signal transduction pathway through which TGF-beta1 induces CTGF, we used SB431542, a specific inhibitor for TGF-beta type I receptor (TbetaRI)/ALK-5 to block TGF-beta1-induced Smad2/3 phosphorylation. Consequently, SB431542 stimulated normal branching morphogenesis and blocked TGF-beta1 inhibition of branching. Furthermore, SB-431542 blocked both endogenous and TGF-beta1-induced expression of CTGF mRNA and protein. These results demonstrate for the first time that TGF-beta1 induces CTGF expression in mouse embryonic lung explants, that CTGF inhibits branching morphogenesis, and that both endogenous and TGF-beta1-induced CTGF expression are mediated by the TbetaRI/ALK-5-dependent Smad2 signaling pathway.
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Affiliation(s)
- Shu Wu
- Department of Pediatrics, Division of Neonatology, University of Miami School of Medicine, P.O. Box 016960, Miami, FL 33101, USA.
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23
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McDevitt TM, Gonzales LW, Savani RC, Ballard PL. Role of endogenous TGF-beta in glucocorticoid-induced lung type II cell differentiation. Am J Physiol Lung Cell Mol Physiol 2006; 292:L249-57. [PMID: 16997883 DOI: 10.1152/ajplung.00088.2006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the fetal lung, endogenous transforming growth factor (TGF)-beta inhibits early morphogenesis and blocks hormone-induced type II cell differentiation. We hypothesized that endogenous TGF-beta inhibits type II cell differentiation and that the stimulatory effects of glucocorticoids result in part from suppression of TGF-beta. Epithelial cells were isolated from human fetal lung and cultured under defined conditions with and without dexamethasone plus cAMP to promote type II cell differentiation. Control cells produced TGF-beta, which was activated in part by alpha(V)beta(6)-integrin. Treatment with dexamethasone, but not cAMP, reduced TGF-beta1 and -beta2 transcripts and TGF-beta bioactivity in culture medium. To examine the effects of decreased TGF-beta in the absence of glucocorticoid, cells were treated with antibodies to TGF-beta and its receptors. By real-time RT-PCR, antibody blockade of TGF-beta reduced serpine1, a TGF-beta-inducible gene, and increased gene expression for sftpa, sftpb, sftpc, and titf1, mimicking the response to hormone treatment. By microarray analysis, 29 additional genes were induced by both TGF-beta antibody and hormone treatment, and 20 other genes were repressed by both treatments. For some genes, the fold response was comparable for antibody and hormone treatment. We conclude that endogenous TGF-beta suppresses expression of surfactant proteins and selected other type II cell genes in fetal lung, in part secondary to increased expression of titf1, and we propose that the mechanism of glucocorticoid-induced type II cell differentiation includes antagonism of TGF-beta gene suppression. Surfactant production during fetal development is likely influenced by relative levels of TGF-beta and glucocorticoids.
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Affiliation(s)
- Theresa M McDevitt
- Division of Neonatology, Department of Pediatrics, University of California-San Francisco, 3333 California St., Suite 150, San Francisco, CA 94118-1981, USA
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24
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Viscardi RM, Atamas SP, Luzina IG, Hasday JD, He JR, Sime PJ, Coalson JJ, Yoder BA. Antenatal Ureaplasma urealyticum respiratory tract infection stimulates proinflammatory, profibrotic responses in the preterm baboon lung. Pediatr Res 2006; 60:141-6. [PMID: 16864693 DOI: 10.1203/01.pdr.0000228322.73777.05] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chronic inflammation and fibrosis are hallmarks of lung pathology of newborn Ureaplasma infection. We hypothesized that antenatally acquired Ureaplasma stimulates a chronic inflammatory, profibrotic immune response that contributes to lung injury, altered developmental signaling, and fibrosis. Lung specimens from 125-d gestation baboon newborns ventilated for 14 d that were either infected antenatally with Ureaplasma serovar 1 or noninfected, and 125-d and 140-d gestational controls were obtained from the Baboon BPD Resource Center (San Antonio, TX). Trichrome stain to assess fibrosis and immunohistochemistry for alpha-smooth muscle actin (alpha-SMA) and transforming growth factor beta1 (TGFbeta1) were performed. Lung homogenates were analyzed by enzyme-linked immunosorbent assay (ELISA) for cytokines [tumor necrosis factor alpha (TNFalpha), interleukin (IL)-1beta, TGFbeta1, oncostatin M (OSM), IL-10, and interferon gamma (IFNgamma)] and the chemokine MCP-1 and by Western blot for Smad2, Smad3, and Smad7. Compared with noninfected ventilated and gestational controls, Ureaplasma-infected lungs demonstrated more extensive fibrosis, increased alpha-SMA and TGFbeta1 immunostaining, and higher concentrations of active TGFbeta1, IL-1beta, and OSM, but no difference in IL-10 levels. There was a trend toward higher Smad2/Smad7 and Smad3/Smad7 ratios in Ureaplasma lung homogenates, consistent with up-regulation of TGFbeta1 signaling. Collectively, these data suggest that a prolonged proinflammatory response initiated by intrauterine Ureaplasma infection contributes to early fibrosis and altered developmental signaling in the immature lung.
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Affiliation(s)
- Rose M Viscardi
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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25
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Del Moral PM, Sala FG, Tefft D, Shi W, Keshet E, Bellusci S, Warburton D. VEGF-A signaling through Flk-1 is a critical facilitator of early embryonic lung epithelial to endothelial crosstalk and branching morphogenesis. Dev Biol 2005; 290:177-88. [PMID: 16375885 DOI: 10.1016/j.ydbio.2005.11.022] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2004] [Revised: 10/10/2005] [Accepted: 11/14/2005] [Indexed: 12/15/2022]
Abstract
Vascular endothelial growth factor-A (VEGF-A) signaling directs both vasculogenesis and angiogenesis. However, the role of VEGF-A ligand signaling in the regulation of epithelial-mesenchymal interactions during early mouse lung morphogenesis remains incompletely characterized. Fetal liver kinase-1 (Flk-1) is a VEGF cognate receptor (VEGF-R2) expressed in the embryonic lung mesenchyme. VEGF-A, expressed in the epithelium, is a high affinity ligand for Flk-1. We have used both gain and loss of function approaches to investigate the role of this VEGF-A signaling pathway during lung morphogenesis. Herein, we demonstrate that exogenous VEGF 164, one of the 3 isoforms generated by alternative splicing of the Vegf-A gene, stimulates mouse embryonic lung branching morphogenesis in culture and increases the index of proliferation in both epithelium and mesenchyme. In addition, it induces differential gene and protein expression among several key lung morphogenetic genes, including up-regulation of BMP-4 and Sp-c expression as well as an increase in Flk-1-positive mesenchymal cells. Conversely, embryonic lung culture with an antisense oligodeoxynucleotide (ODN) to the Flk-1 receptor led to reduced epithelial branching, decreased epithelial and mesenchymal proliferation index as well as downregulating BMP-4 expression. These results demonstrate that the VEGF pathway is involved in driving epithelial to endothelial crosstalk in embryonic mouse lung morphogenesis.
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Affiliation(s)
- Pierre-Marie Del Moral
- Developmental Biology Program, Saban Research Institute, Children's Hospital Los Angeles, Department of Pediatric Surgery, USC Keck School of Medicine, 4650 Sunset Blvd., Los Angeles, CA 90027, USA
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26
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Roth-Kleiner M, Post M. Similarities and dissimilarities of branching and septation during lung development. Pediatr Pulmonol 2005; 40:113-34. [PMID: 15965895 DOI: 10.1002/ppul.20252] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The lungs of small premature babies are at a developmental stage of finalizing their airway tree by a process called branching morphogenesis, and of creating terminal gas exchange units by a mechanism called septation. If the branching process is disturbed, the lung has a propensity to be hypoplastic. If septation is impaired, the terminal gas exchange units, the alveoli, tend to be enlarged and reduced in number, an entity known as bronchopulmonary dysplasia. Here, we review current knowledge of key molecules influencing branching and septation. In particular, we discuss the molecular similarities and dissimilarities between the two processes of airspace enlargement. Understanding of the molecular mechanisms regulating branching and septation may provide perinatologists with targets for improving lung growth and maturation.
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Affiliation(s)
- Matthias Roth-Kleiner
- Lung Biology Program, Hospital for Sick Children Research Institute, and Department of Laboratory Medicine, University of Toronto, Toronto, Ontario, Canada
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27
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Kim IM, Ramakrishna S, Gusarova GA, Yoder HM, Costa RH, Kalinichenko VV. The Forkhead Box M1 Transcription Factor Is Essential for Embryonic Development of Pulmonary Vasculature. J Biol Chem 2005; 280:22278-86. [PMID: 15817462 DOI: 10.1074/jbc.m500936200] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Transgenic and gene knock-out studies demonstrated that the mouse Forkhead Box m1 (Foxm1 or Foxm1b) transcription factor (previously called HFH-11B, Trident, Win, or MPP2) is essential for hepatocyte entry into mitosis during liver development, regeneration, and liver cancer. Targeted deletion of Foxm1 gene in mice produces an embryonic lethal phenotype due to severe abnormalities in the development of liver and heart. In this study, we show for the first time that Foxm1(-/-) lungs exhibit severe hypertrophy of arteriolar smooth muscle cells and defects in the formation of peripheral pulmonary capillaries as evidenced by significant reduction in platelet endothelial cell adhesion molecule 1 staining of the distal lung. Consistent with these findings, significant reduction in proliferation of the embryonic Foxm1(-/-) lung mesenchyme was found, yet proliferation levels were normal in the Foxm1-deficient epithelial cells. Severe abnormalities of the lung vasculature in Foxm1(-/-) embryos were associated with diminished expression of the transforming growth factor beta receptor II, a disintegrin and metalloprotease domain 17 (ADAM-17), vascular endothelial growth factor receptors, Polo-like kinase 1, Aurora B kinase, laminin alpha4 (Lama4), and the Forkhead Box f1 transcription factor. Cotransfection studies demonstrated that Foxm1 stimulates transcription of the Lama4 promoter, and this stimulation requires the Foxm1 binding sites located between -1174 and -1145 bp of the mouse Lama4 promoter. In summary, development of mouse lungs depends on the Foxm1 transcription factor, which regulates expression of genes essential for mesenchyme proliferation, extracellular matrix remodeling, and vasculogenesis.
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Affiliation(s)
- Il-Man Kim
- Department of Medicine and Committee on Developmental Biology, The University of Chicago, Chicago, IL 60637, USA
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Warburton D, Bellusci S, De Langhe S, Del Moral PM, Fleury V, Mailleux A, Tefft D, Unbekandt M, Wang K, Shi W. Molecular mechanisms of early lung specification and branching morphogenesis. Pediatr Res 2005; 57:26R-37R. [PMID: 15817505 DOI: 10.1203/01.pdr.0000159570.01327.ed] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The "hard wiring" encoded within the genome that determines the emergence of the laryngotracheal groove and subsequently early lung branching morphogenesis is mediated by finely regulated, interactive growth factor signaling mechanisms that determine the automaticity of branching, interbranch length, stereotypy of branching, left-right asymmetry, and finally gas diffusion surface area. The extracellular matrix is an important regulator as well as a target for growth factor signaling in lung branching morphogenesis and alveolarization. Coordination not only of epithelial but also endothelial branching morphogenesis determines bronchial branching and the eventual alveolar-capillary interface. Improved prospects for lung protection, repair, regeneration, and engineering will depend on more detailed understanding of these processes. Herein, we concisely review the functionally integrated morphogenetic signaling network comprising the critical bone morphogenetic protein, fibroblast growth factor, Sonic hedgehog, transforming growth factor-beta, vascular endothelial growth factor, and Wnt signaling pathways that specify and drive early embryonic lung morphogenesis.
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Affiliation(s)
- David Warburton
- Developmental Biology Program, The Saban Research Institute of Childrens Hospital Los Angeles, CA 90027, USA.
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Abstract
Our understanding of lung development in the past two decades has moved from an anatomical to a histological basis and, most recently, to a molecular basis. Tissue interactions specify tracheal and lung primordia formation, program branching morphogenesis of the airway epithelium and regulate epithelial differentiation. In addition, lung development is influenced by mechanical and humoral factors. The regulatory molecules involved in morphogenetic signaling include growth and transcription factors and extracellular matrix molecules. These morphogenetic signals are responsible for lung patterning and differentiation. We will provide a brief overview of molecular signaling during early respiratory formation, airway branching, pulmonary vascularization and epithelial differentiation. We will then review aberrant morphogenetic signaling in human lung abnormalities, such as tracheoesophageal fistula, congenital diaphragmatic hernia, pulmonary hyperplasia, alveolar capillary dysplasia, congenital cystic adenomatoid malformation and bronchopulmonary dysplasia.
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Affiliation(s)
- Frederick Groenman
- Program in Lung Biology Research, Hospital for Sick Children Research Institute, Department of Pediatrics, University of Toronto, Toronto, Canada
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De Langhe SP, Sala FG, Del Moral PM, Fairbanks TJ, Yamada KM, Warburton D, Burns RC, Bellusci S. Dickkopf-1 (DKK1) reveals that fibronectin is a major target of Wnt signaling in branching morphogenesis of the mouse embryonic lung. Dev Biol 2005; 277:316-31. [PMID: 15617677 DOI: 10.1016/j.ydbio.2004.09.023] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Revised: 09/16/2004] [Accepted: 09/20/2004] [Indexed: 12/15/2022]
Abstract
Members of the Dickkopf (Dkk) family of secreted proteins are potent inhibitors of Wnt/beta-catenin signaling. In this study we show that Dkk1, -2, and -3 are expressed distally in the epithelium, while Kremen1, the needed co-receptor, is expressed throughout the epithelium of the developing lung. Using TOPGAL mice [DasGupta, R., Fuchs, E., 1999. Multiple roles for activated LEF/TCF transcription complexes during hair follicle development and differentiation. Development 126, 4557-4568] to monitor the Wnt pathway, we show that canonical Wnt signaling is dynamic in the developing lung and is active throughout the epithelium and in the proximal smooth muscle cells (SMC) until E12.5. However, from E13.5 onwards, TOPGAL activity is absent in the SMC and is markedly reduced in the distal epithelium coinciding with the onset of Dkk-1 expression in the distal epithelium. To determine the role of Wnt signaling in early lung development, E11.5 organ cultures were treated with recombinant DKK1. Treated lungs display impaired branching, characterized by failed cleft formation and enlarged terminal buds, and show decreased alpha-smooth muscle actin (alpha-SMA) expression as well as defects in the formation of the pulmonary vasculature. These defects coincide with a pattern of decreased fibronectin (FN) deposition. DKK1-induced morphogenetic defects can be mimicked by inhibition of FN and overcome by addition of exogenous FN, suggesting an involvement of FN in Wnt-regulated morphogenetic processes.
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Affiliation(s)
- Stijn P De Langhe
- Developmental Biology Program, Department of Surgery, USC Keck School of Medicine and the Saban Research Institute of Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
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31
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Warburton D, Bellusci S, Del Moral PM, Kaartinen V, Lee M, Tefft D, Shi W. Growth factor signaling in lung morphogenetic centers: automaticity, stereotypy and symmetry. Respir Res 2003; 4:5. [PMID: 12818006 PMCID: PMC185249 DOI: 10.1186/1465-9921-4-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2002] [Revised: 01/28/2003] [Accepted: 02/17/2003] [Indexed: 12/16/2022] Open
Abstract
Lung morphogenesis is stereotypic, both for lobation and for the first several generations of airways, implying mechanistic control by a well conserved, genetically hardwired developmental program. This program is not only directed by transcriptional factors and peptide growth factor signaling, but also co-opts and is modulated by physical forces. Peptide growth factors signal within repeating epithelial-mesenchymal temporospatial patterns that constitute morphogenetic centers, automatically directing millions of repetitive events during both stereotypic branching and nonstereotypic branching as well as alveolar surface expansion phases of lung development. Transduction of peptide growth factor signaling within these centers is finely regulated at multiple levels. These may include ligand expression, proteolytic activation of latent ligand, ligand bioavailability, ligand binding proteins and receptor affinity and presentation, receptor complex assembly and kinase activation, phosphorylation and activation of adapter and messenger protein complexes as well as downstream events and cross-talk both inside and outside the nucleus. Herein we review the critical Sonic Hedgehog, Fibroblast Growth Factor, Bone Morphogenetic Protein, Vascular Endothelial Growth Factor and Transforming Growth Factorbeta signaling pathways and propose how they may be functionally coordinated within compound, highly regulated morphogenetic gradients that drive first stereotypic and then non-stereotypic, automatically repetitive, symmetrical as well as asymmetrical branching events in the lung.
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Affiliation(s)
- David Warburton
- Developmental Biology Program, Childrens Hospital Los Angeles Research Institute and the Center for Craniofacial Molecular Biology, Keck School of Medicine and School of Dentistry, University of Southern California
| | - Saverio Bellusci
- Developmental Biology Program, Childrens Hospital Los Angeles Research Institute and the Center for Craniofacial Molecular Biology, Keck School of Medicine and School of Dentistry, University of Southern California
| | - Pierre-Marie Del Moral
- Developmental Biology Program, Childrens Hospital Los Angeles Research Institute and the Center for Craniofacial Molecular Biology, Keck School of Medicine and School of Dentistry, University of Southern California
| | - Vesa Kaartinen
- Developmental Biology Program, Childrens Hospital Los Angeles Research Institute and the Center for Craniofacial Molecular Biology, Keck School of Medicine and School of Dentistry, University of Southern California
| | - Matt Lee
- Developmental Biology Program, Childrens Hospital Los Angeles Research Institute and the Center for Craniofacial Molecular Biology, Keck School of Medicine and School of Dentistry, University of Southern California
| | - Denise Tefft
- Developmental Biology Program, Childrens Hospital Los Angeles Research Institute and the Center for Craniofacial Molecular Biology, Keck School of Medicine and School of Dentistry, University of Southern California
| | - Wei Shi
- Developmental Biology Program, Childrens Hospital Los Angeles Research Institute and the Center for Craniofacial Molecular Biology, Keck School of Medicine and School of Dentistry, University of Southern California
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32
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Abstract
Formation of branching epithelial trees from unbranched precursors is a common process in animal organogenesis. In humans, for example, this process gives rise to the airways of the lungs, the urine-collecting ducts of the kidneys and the excretory epithelia of the mammary, prostate and salivary glands. Branching in these different organs, and in different animal classes and phyla, is morphologically similar enough to suggest that they might use a conserved developmental programme, while being dissimilar enough not to make it obviously certain that they do. In this article, I review recent discoveries about the molecular regulation of branching morphogenesis in the best-studied systems, and present evidence for and against the idea of there being a highly conserved mechanism. Overall, I come to the tentative conclusion that key mechanisms are highly conserved, at least within vertebrates, but acknowledge that more work needs to be done before the case is proved beyond reasonable doubt.
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Affiliation(s)
- Jamie A Davies
- Anatomy Building, Edinburgh University Medical School, Scotland.
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Leinwand MJ, Tefft JD, Zhao J, Coleman C, Anderson KD, Warburton D. Nitrofen inhibition of pulmonary growth and development occurs in the early embryonic mouse. J Pediatr Surg 2002; 37:1263-8. [PMID: 12194114 DOI: 10.1053/jpsu.2002.34978] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND/PURPOSE It was believed previously that pulmonary hypoplasia in congenital diaphragmatic hernia (CDH) was a consequence of the herniation of abdominal viscera into the chest. Using the murine nitrofen-induced model of CDH, the authors evaluated lung growth and development before diaphragm closure or herniation. METHODS The authors examined nitrofen-exposed early embryonic lungs on embryonic day 12 (E12). Branching morphogenesis was quantified before and after 4 days in culture in serumless chemically defined media and compared with age-matched control lungs. The mRNA expression of proliferative and developmental markers in cultured lungs was then determined. RESULTS Nitrofen-exposed lungs had 30% fewer total terminal branches than age-matched controls (9.3 +/- 1.9 nitrofen v 13.7 +/- 2.6 control; P <.001). Hypoplasia also was more profound in the left than the right lung. These effects persisted after culturing the lungs for 4 days in serumless chemically-defined media (31.7 +/- 6.8 nitrofen v 42.9 +/- 8.4 control, P <.001). Furthermore, the mRNA expression of proliferative and developmental markers was decreased in nitrofen-exposed E12 lungs cultured for 4 days (as a percentage of age-matched controls): cyclin A (69.28%; P =.04), Nkx2.1 (44.4%, 0.04), SP-A (24.1%; P =.008), SP-B (23.4%; P =.05), SP-C (20%; P =.06), and CC-10 (13.8%; P =.04). CONCLUSION Nitrofen induces primary pulmonary hypoplasia and immaturity in the early embryonic mouse, and this effect persists in culture.
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Affiliation(s)
- Michael J Leinwand
- Division of Pediatric Surgery and Developmental Biology Program, Childrens Hospital Los Angeles Research Institute, Los Angeles, CA, USA
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34
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Leinwand MJ, Zhao J, Tefft JD, Anderson KD, Warburton D. Murine nitrofen-induced pulmonary hypoplasia does not involve induction of TGF-beta signaling. J Pediatr Surg 2002; 37:1123-7. [PMID: 12149686 DOI: 10.1053/jpsu.2002.34456] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND/PURPOSE In the murine nitrofen-induced model of congenital diaphragmatic hernia (CDH), the lungs are primarily hypoplastic and immature even before diaphragmatic closure. Because excess transforming growth factor-beta (TGF-beta) signaling induces pulmonary hypoplasia, the authors hypothesized that primary hypoplasia after nitrofen exposure may be caused by aberrant signaling by the TGF-beta pathway. Therefore, abrogation of TGF-beta signaling might rescue the hypoplasia. METHODS The authors performed intratracheal microinjections of a recombinant adenoviral vector encoding a dominant-negative TGF-beta type II receptor (AdIIR-DN) in nitrofen-exposed and control E12 mouse lungs, which then were cultured for 4 days in serumless chemically defined media. The mRNA expression of Smad2, 3, 4, and 7 in nitrofen-exposed and control E12 lungs after 4 days in culture were compared. RESULTS ADIIR-DN increased terminal branching in control lungs by 28% compared with lungs injected with control virus (61.8 +/- 4.6 v. 48.4 +/- 4.7, P =.004). However, there was no difference between nitrofen-exposed lungs injected with ADIIR-DN and those injected with control virus. Compared with control lungs, Smad mRNA expression was decreased markedly in nitrofen-exposed lungs: Smad2 (40%, P =.16), Smad3 (29%, P =.02), Smad4 (25%, P =.07), and Smad7 (36%, P =.04). CONCLUSIONS Because abrogation of TGF-beta signaling does not rescue the hypoplasia seen in the nitrofen model, and Smad expression is decreased in nitrofen-exposed lungs, the TGF-beta pathway does not appear to play a role in nitrofen-induced pulmonary hypoplasia.
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Affiliation(s)
- Michael J Leinwand
- Division of Pediatric Surgery, Childrens Hospital Los Angeles Research Institute and Center for Craniofacial and Molecular Biology, University of Southern California Schools of Medicine and Dentistry, Los Angeles, CA, USA
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35
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Yu Y, Yang JL, Chapman-Sheath PJ, Walsh WR. TGF-beta, BMPS, and their signal transducing mediators, Smads, in rat fracture healing. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2002; 60:392-7. [PMID: 11920662 DOI: 10.1002/jbm.1289] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Smads are cytoplasmic signal transducers of transforming growth factor-beta (TGF-beta) and bone morphogenetic proteins (BMPs). Their relation to fracture healing is unknown. This study examined the temporal protein expression of Smads, together with TGF-beta and BMPs, using immunohistochemistry in a rodent fracture model. Over-expression of TGF-beta, BMPs-2, 4, and 7, common-mediator Smad (Smad4), and receptor-regulated Smads (Smads1, 2, 3, and 5) versus lower levels of inhibitory Smad (Smad6), were detected at day 3 in osteogenic cells in the thickened periosteum and bone marrow at the fracture sites. At day 10, Smad6 increased dramatically, Smad2, Smad3, and Smad4 remained elevated while Smad1 and Smad5 decreased in the fracture callus. Smad7 was expressed only in vascular endothelial cells. By day 28, when new bone had replaced the fracture callus, all the protein regulators decreased, approaching control levels. During fracture healing, the expression patterns of Smads1 and 5 were similar to that of BMPs-2 and 7 whereas the expression of Smads2 and 3 was parallel with that of TGF-beta. The Smad family, associated with BMPs and TGF-beta, may play an important role in the early stage of rat fracture healing.
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Affiliation(s)
- Yan Yu
- Orthopaedic Research Laboratories, Division of Surgery, Prince of Wales Hospital, Faculty of Medicine, University of New South Wales, Sydney, NSW 2031, Australia
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36
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Zhao J, Shi W, Wang YL, Chen H, Bringas P, Datto MB, Frederick JP, Wang XF, Warburton D. Smad3 deficiency attenuates bleomycin-induced pulmonary fibrosis in mice. Am J Physiol Lung Cell Mol Physiol 2002; 282:L585-93. [PMID: 11839555 DOI: 10.1152/ajplung.00151.2001] [Citation(s) in RCA: 312] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transforming growth factor-beta (TGF-beta) signaling plays an important regulatory role during lung fibrogenesis. Smad3 was identified in the pathway for transducing TGF-beta signals from the cell membrane to the nucleus. Using mice without Smad3 gene expression, we investigated whether Smad3 could regulate bleomycin-induced pulmonary fibrosis in vivo. Mice deficient in Smad3 demonstrated suppressed type I procollagen mRNA expression and reduced hydroxyproline content in the lungs compared with wild-type mice treated with bleomycin. Furthermore, loss of Smad3 greatly attenuated morphological fibrotic responses to bleomycin in the mouse lungs, suggesting that Smad3 is implicated in the pathogenesis of pulmonary fibrosis. These results show that Smad3 contributes to bleomycin-induced lung injury and that Smad3 may serve as a novel target for potential therapeutic treatment of lung fibrosis.
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Affiliation(s)
- Jingsong Zhao
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California 90033, USA.
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37
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Bragg AD, Moses HL, Serra R. Signaling to the epithelium is not sufficient to mediate all of the effects of transforming growth factor beta and bone morphogenetic protein 4 on murine embryonic lung development. Mech Dev 2001; 109:13-26. [PMID: 11677049 DOI: 10.1016/s0925-4773(01)00508-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many studies have suggested that transforming growth factor beta (TGF-beta) and bone morphogenetic protein 4 (Bmp4) regulate early development of the lung. In this study, administration of growth factors directly into the lumen of lungs grown in organ culture was used to limit their activity to the epithelium and test the hypothesis that signaling to the epithelium is sufficient to mediate the known effects of TGF-beta and BMP-4 on early lung development. Addition of TGF-beta1, beta2, or beta3 to the medium surrounding lungs grown in organ culture resulted in decreased branching, reduced cell proliferation, accumulation of alpha-smooth muscle actin protein (alpha-SMA) in the mesenchyme, and decreased expression of a marker for respiratory epithelium, surfactant protein-C (Sp-C). When TGF-beta1 was restricted to the epithelium, accumulation of alpha-SMA and inhibition of Sp-C expression were not observed but branching and proliferation were inhibited. In contrast, branching was not inhibited in lungs where TGF-beta2 or TGF-beta3 were restricted to the epithelium suggesting differences in the mechanism of signaling by TGF-beta1, TGF-beta2 or TGF -beta3 in lung. Addition of Bmp4 to the medium surrounding lungs grown in organ culture stimulated cell proliferation and branching morphogenesis; however, direct injection of Bmp4 into the lung lumen had no effect on proliferation or branching. Based on these data and data from mesenchyme-free cultures, we propose that the mesenchyme influences growth factor signaling in the lung.
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Affiliation(s)
- A D Bragg
- Vanderbilt Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232, USA
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38
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Abstract
Development of glandular organs such as the kidney, lung, and prostate involves the process of branching morphogenesis. The developing organ begins as an epithelial bud that invades the surrounding mesenchyme, projecting dividing epithelial cords or tubes away from the site of initiation. This is a tightly regulated process that requires complex epithelial-mesenchymal interactions, resulting in a three-dimensional treelike structure. We propose that activins are key growth and differentiation factors during this process. The purpose of this review is to examine the direct, indirect, and correlative lines of evidence to support this hypothesis. The expression of activins is reviewed together with the effect of activins and follistatins in the development of branched organs. We demonstrate that activin has both negative and positive effects on cell growth during branching morphogenesis, highlighting the complex nature of activin in the regulation of proliferation and differentiation. We propose potential mechanisms for the way in which activins modify branching and address the issue of whether activin is a regulator of branching morphogenesis.
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Affiliation(s)
- E M Ball
- Centre for Urological Research, Monash University, Melbourne, Victoria, Australia.
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Rosendahl A, Checchin D, Fehniger TE, ten Dijke P, Heldin CH, Sideras P. Activation of the TGF-beta/activin-Smad2 pathway during allergic airway inflammation. Am J Respir Cell Mol Biol 2001; 25:60-8. [PMID: 11472976 DOI: 10.1165/ajrcmb.25.1.4396] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Changes in the levels of transforming growth factor (TGF)-beta cytokines or receptors observed during the progression of several inflammatory and fibrotic disorders have been used to implicate these cytokines in the pathophysiology of these diseases. Although correlative, these studies were inconclusive because they were unable to demonstrate actual continuous TGF-beta-mediated signaling in the involved tissues. We reasoned that the phosphorylation state and subcellular localization of Smad2, the intracellular effector of TGF-beta/activin-mediated signaling, could be used as a marker of active signaling mediated by these cytokines in situ. We therefore used an experimental model of ovalbumin-induced allergic airway inflammation and were able to demonstrate a dramatic increase in the numbers of bronchial epithelial, alveolar, and infiltrating inflammatory cells expressing nuclear phosphorylated Smad2 within the allergen-challenged lungs. This was accompanied by strong upregulation of the activin receptor ALK-4/ActR-IB and redistribution of the TGF-beta responsive ALK-5/TbetaR-I. Although levels of TGF-beta1, TGF-beta2, and TGF-beta3 messenger RNA (mRNA) were marginally altered, the level of activin mRNA was strongly upregulated during the inflammatory response. Our data illustrate the usefulness of antiphosphorylated Smad antibodies in demonstrating active TGF- beta/activin-mediated signaling in vivo and strongly suggest that activin/Smad-mediated signaling could be a critical contributor in the pathophysiology of allergic pulmonary diseases.
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Affiliation(s)
- A Rosendahl
- Department of Molecular Sciences and Biosciences, AstraZeneca R&D Lund, Scheelevägen 2, S-221 87 Lund, Sweden.
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Zhao J, Chen H, Peschon JJ, Shi W, Zhang Y, Frank SJ, Warburton D. Pulmonary hypoplasia in mice lacking tumor necrosis factor-alpha converting enzyme indicates an indispensable role for cell surface protein shedding during embryonic lung branching morphogenesis. Dev Biol 2001; 232:204-18. [PMID: 11254358 DOI: 10.1006/dbio.2001.0176] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Many membrane-bound protein precursors, including cytokines and growth factors, are proteolytically shed to yield soluble intercellular regulatory ligands. The responsible protease, tumor necrosis factor-alpha converting enzyme (TACE/ADAM-17), is a transmembrane metalloprotease-disintegrin that cleaves multiple cell surface proteins, although it was initially identified for the enzymatic release of tumor necrosis factor-alpha (TNF-alpha). Mammalian lung growth and development are tightly controlled by cytokines and peptide growth factors. However, the biological function of the cell shedding mechanism during lung organogenesis is not understood. We therefore evaluated the role of TACE as a "sheddase" during lung morphogenesis by analyzing the developmental phenotypes of lungs in mice with an inactive TACE gene in both in vivo and ex vivo organ explant culture. Neonatal TACE-deficient mice had visible respiratory distress and their lungs failed to form normal saccular structures. These newborn mutant lungs had fewer peripheral epithelial sacs with deficient septation and thick-walled mesenchyme, resulting in reduced surface for gas exchange. At the canalicular stage of E16.5, the lungs of TACE mutant mice were impaired in branching morphogenesis, inhibited in epithelial cell proliferation and differentiation, and delayed in vasculogenesis. Embryonic TACE knockout mouse lungs (E12) branched poorly compared to wild-type lungs, when placed into serumless organ culture. Gene expression of both surfactant protein-C and aquaporin-5 were inhibited in cultured TACE-mutant embryonic lungs, indicating defects in both branching and peripheral epithelial cytodifferentiation in the absence of TACE protein. Furthermore, both the hypoplastic phenotype and the delayed cytodifferentiation in TACE-deficient lungs were rescued by exogenous addition of soluble stimulatory factors including either TNF-alpha or epidermal growth factor in embryonic lung culture. Thus, the impaired lung branching and maturation without TACE suggest a broad role for TACE in the processing of multiple membrane-anchored proteins, one or more of which is essential for normal lung morphogenesis. Taken together, our data indicate that the TACE-mediated proteolytic mechanism which enzymatically releases membrane-tethered proteins plays an indispensable role in lung morphogenesis, and its inactivation leads to abnormal lung development.
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Affiliation(s)
- J Zhao
- Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar St., CSA 103, Los Angeles, California, 90033, USA.
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Mailleux AA, Tefft D, Ndiaye D, Itoh N, Thiery JP, Warburton D, Bellusci S. Evidence that SPROUTY2 functions as an inhibitor of mouse embryonic lung growth and morphogenesis. Mech Dev 2001; 102:81-94. [PMID: 11287183 DOI: 10.1016/s0925-4773(01)00286-6] [Citation(s) in RCA: 187] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Experimental evidence is rapidly emerging that the coupling of positive regulatory signals with the induction of negative feedback modulators is a mechanism of fine regulation in development. Studies in Drosophila and chick have shown that members of the SPROUTY family are inducible negative regulators of growth factors that act through tyrosine kinase receptors. We and others have shown that Fibroblast Growth Factor 10 (FGF10) is a key positive regulator of lung branching morphogenesis. Herein, we provide direct evidence that mSprouty2 is dynamically expressed in the peripheral endoderm in embryonic lung and is downregulated in the clefts between new branches at E12.5. We found that mSprouty2 was expressed in a domain restricted in time and space, adjacent to that of Fgf10 in the peripheral mesenchyme. By E14.5, Fgf10 expression was restricted to a narrow domain of mesenchyme along the extreme edges of the individual lung lobes, whereas mSprouty2 was most highly expressed in the subjacent epithelial terminal buds. FGF10 beads upregulated the expression of mSprouty2 in adjacent epithelium in embryonic lung explant culture. Lung cultures treated with exogenous FGF10 showed greater branching and higher levels of mSpry2 mRNA. Conversely, Fgf10 antisense oligonucleotides reduced branching and decreased mSpry2 mRNA levels. However, treatment with exogenous FGF10 or antisense Fgf10 did not change Shh and FgfR2 mRNA levels in the lungs. We investigated Sprouty2 function during lung development by two different but complementary approaches. The targeted overexpression of mSprouty2 in the peripheral lung epithelium in vivo, using the Surfactant Protein C promoter, resulted in a low level of branching, lung lobe edges abnormal in appearance and the inhibition of epithelial proliferation. Transient high-level overexpression of mSpry2 throughout the pulmonary epithelium by intra-tracheal adenovirus microinjection also resulted in a low level of branching. These results indicate for the first time that mSPROUTY2 functions as a negative regulator of embryonic lung morphogenesis and growth.
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Affiliation(s)
- A A Mailleux
- UMR144-CNRS/Institut Curie, 26 rue d'Ulm, 75248 Cedex 05, Paris, France
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Flanders KC, Kim ES, Roberts AB. Immunohistochemical expression of Smads 1-6 in the 15-day gestation mouse embryo: signaling by BMPs and TGF-betas. Dev Dyn 2001; 220:141-54. [PMID: 11169847 DOI: 10.1002/1097-0177(2000)9999:9999<::aid-dvdy1096>3.0.co;2-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The eight mammalian Smad proteins mediate cellular signaling from members of the transforming growth factor-beta (TGF-beta), bone morphogenetic protein (BMP), and activin families. Smads 1, 5, and 8 transmit signals from BMPs, while Smads 2 and 3 transmit signals from TGF-betas and activin. Smad 4 is a common mediator of both pathways, while Smads 6 and 7 inhibit signaling. Signal transduction involves translocation of Smad complexes to the nucleus and subsequent gene activation. Little is known about the expression of endogenous Smad proteins during development. We identified commercially available Smad antibodies that specifically recognize a unique Smad protein and are suitable for immunohistochemistry. Here we compare the localization of Smads 1, 2, 3, 4, 5, and 6 in tissues of the 15-day gestation mouse embryo. Immunoreactive Smad proteins are seen in many tissues with differences in the localization being dependent upon the cell type. All tissues express Smad 4 and at least one each of the BMP-specific and TGF-beta-specific Smads, while expression of Smad 6 is more restricted. Differences are observed in the nuclear versus cytoplasmic localization among the Smads in different cell types or tissues, suggesting selective activation of Smads during this stage of development.
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Affiliation(s)
- K C Flanders
- Laboratory of Cell Regulation and Carcinogenesis, National Cancer Institute, Bethesda, MD 20892-5055, USA.
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43
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Mendelson CR. Role of transcription factors in fetal lung development and surfactant protein gene expression. Annu Rev Physiol 2000; 62:875-915. [PMID: 10845115 DOI: 10.1146/annurev.physiol.62.1.875] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Branching morphogenesis of the lung and differentiation of specialized cell populations is dependent upon reciprocal interactions between epithelial cells derived from endoderm of embryonic foregut and surrounding mesenchymal cells. These interactions are mediated by elaboration and concerted actions of a variety of growth and differentiation factors binding to specific receptors. Such factors include members of the fibroblast growth factor family, sonic hedgehog, members of the transforming growth factor-beta family, epidermal growth factor, and members of the platelet-derived growth factor family. Hormones that increase cyclic AMP formation, glucocorticoids, and retinoids also play important roles in branching morphogenesis, alveolar development, and cellular differentiation. Expression of the genes encoding these morphogens and their receptors is controlled by a variety of transcription factors that also are highly regulated. Several of these transcription factors serve dual roles as regulators of genes involved in early lung development and in specialized functions of differentiated cells. Targeted null mutations of genes encoding many of these morphogens and transcription factors have provided important insight into their function during lung development. In this chapter, the cellular and molecular mechanisms that control lung development are considered, as well as those that regulate expression of the genes encoding the surfactant proteins.
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Affiliation(s)
- C R Mendelson
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas 75235-9038, USA.
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Muraoka RS, Bushdid PB, Brantley DM, Yull FE, Kerr LD. Mesenchymal expression of nuclear factor-kappaB inhibits epithelial growth and branching in the embryonic chick lung. Dev Biol 2000; 225:322-38. [PMID: 10985853 DOI: 10.1006/dbio.2000.9824] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
It is becoming increasingly recognized that the ubiquitous, inducible transcription factor nuclear factor-kappaB (NF-kappaB) is involved in developmental processes. For example, NF-kappaB acts as a mediator of epithelial-mesenchymal interactions in the developing chick limb. We investigated the role of NF-kappaB in directing the branching morphogenesis of the developing chick lung, a process which relies on epithelial-mesenchymal communication. High level expression of relA was found in the mesenchyme surrounding the nonbranching structures of the lung but was not detected either in the mesenchyme surrounding the branching structures of the distal lung or in the developing lung epithelium. Specific inhibition of mesenchymal NF-kappaB in lung cultures resulted in increased epithelial budding. Conversely, expression of a trans-dominant activator of NF-kappaB in the lung mesenchyme repressed budding. Ectopic expression of RelA was sufficient to inhibit the ability of the distal mesenchyme to induce epithelial bud formation. Cellular proliferation in the mesenchyme was inhibited by hyperactivation of NF-kappaB in the mesenchyme of lung cultures. Interestingly, increased NF-kappaB activity in the mesenchyme also decreased the proliferation of the associated epithelium, while inhibition of NF-kappaB activity increased cellular proliferation in lung cultures. Expression patterns of several genes which are known to influence lung branching morphogenesis were altered in response to changes in mesenchymal NF-kappaB activity, including fgf10, bmp-4, and tgf-beta1. Thus NF-kappaB represents the first transcription factor reported to function within the lung mesenchyme to limit growth and branching of the adjacent epithelium.
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Affiliation(s)
- R S Muraoka
- Department of Cell Biology, Vanderbilt-Ingram Cancer Center, Nashville, Tennessee 37232-2363, USA
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Zhao J, Shi W, Chen H, Warburton D. Smad7 and Smad6 differentially modulate transforming growth factor beta -induced inhibition of embryonic lung morphogenesis. J Biol Chem 2000; 275:23992-7. [PMID: 10801843 DOI: 10.1074/jbc.m002433200] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transforming growth factors beta (TGF-beta) are known negative regulators of lung development, and excessive TGF-beta production has been noted in pulmonary hypoplasia associated with lung fibrosis. Inhibitory Smad7 was recently identified to antagonize TGF-beta family signaling by interfering with the activation of TGF-beta signal-transducing Smad complexes. To investigate whether Smad7 can regulate TGF-beta-induced inhibition of lung morphogenesis, ectopic overexpression of Smad7 was introduced into embryonic mouse lungs in culture using a recombinant adenovirus containing Smad7 cDNA. Although exogenous TGF-beta efficiently reduced epithelial lung branching morphogenesis in control virus-infected lung culture, TGF-beta-induced branching inhibition was abolished after epithelial transfer of the Smad7 gene into lungs in culture. Smad7 also prevented TGF-beta-mediated down-regulation of surfactant protein C gene expression, a marker of bronchial epithelial differentiation, in cultured embryonic lungs. Moreover, we found that Smad7 transgene expression blocked Smad2 phosphorylation induced by exogenous TGF-beta ligand in lung culture, indicating that Smad7 exerts its inhibitory effect on both lung growth and epithelial cell differentiation through modulation of TGF-beta pathway-restricted Smad activity. However, the above anti-TGF-beta signal transduction effects were not observed in cultured embryonic lungs with Smad6 adenoviral gene transfer, suggesting that Smad7 and Smad6 differentially regulate TGF-beta signaling in developing lungs. Our data therefore provide direct evidence that Smad7, but not Smad6, prevents TGF-beta-mediated inhibition of both lung branching morphogenesis and cytodifferentiation, establishing the mechanistic basis for Smad7 as a novel target to ameliorate aberrant TGF-beta signaling during lung development, injury, and repair.
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Affiliation(s)
- J Zhao
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California 90033, USA.
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46
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Kumar AS, Gonzales LW, Ballard PL. Transforming growth factor-beta(1) regulation of surfactant protein B gene expression is mediated by protein kinase-dependent intracellular translocation of thyroid transcription factor-1 and hepatocyte nuclear factor 3. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1492:45-55. [PMID: 11004479 DOI: 10.1016/s0167-4781(00)00058-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The transforming growth factor-beta (TGF beta) polypeptides control a variety of cellular processes including organogenesis and cellular proliferation and differentiation. In the developing lung, TGF beta(1) treatment inhibits airway branching and expression of the genes for surfactant proteins (SP). Many effects of TGF beta are mediated at the level of gene transcription but there is limited information regarding signaling pathways and target transcription factors. In this study with human pulmonary adenocarcinoma H441 cells, we investigated TGF beta(1) effects on SP-B, a protein which is essential for normal function of pulmonary surfactant. TGF beta(1) (10 ng/ml) reduced SP-B mRNA content in a time-dependent fashion, and transient transfection studies localized responsiveness to the region of the SP-B promoter (-112/-72 bp) containing binding sites for thyroid transcription factor-1 (TTF-1) and hepatocyte nuclear factor 3 (HNF3), transcription factors that are important enhancers of SP gene expression. Using electrophoretic mobility shift assay and immunofluorescence, we demonstrated rapid accumulation of these transcription factors in the cytoplasm and subsequent loss from the nucleus on TGF beta(1) treatment of both adenocarcinoma cells and cultured human fetal lung. TGF beta(1) treatment caused intracellular translocation of protein kinase C and effects of TGF beta(1) were mostly abrogated in the presence of the protein kinase inhibitor calphostin C. We conclude that TGF beta(1), acting via protein phosphorylation, blocks nuclear translocation of TTF-1 and HNF3 which results in down-regulation of the SP-B gene and presumably other pulmonary genes which are transactivated by these factors.
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Affiliation(s)
- A S Kumar
- Institute for Environmental Medicine, University of Pennsylvania School of Medicine, Philadelphia, 19104-6068, USA
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Chen SJ, Yuan W, Lo S, Trojanowska M, Varga J. Interaction of smad3 with a proximal smad-binding element of the human alpha2(I) procollagen gene promoter required for transcriptional activation by TGF-beta. J Cell Physiol 2000; 183:381-92. [PMID: 10797313 DOI: 10.1002/(sici)1097-4652(200006)183:3<381::aid-jcp11>3.0.co;2-o] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Transcription of the alpha2(I) collagen gene (COL1A2) in fibroblasts is potently induced by transforming growth factor-beta (TGF-beta). Smad family proteins function as intracellular signal transducers for TGF-beta that convey information from the cell membrane to the nucleus. In the present study, we establish the functional requirement for endogenous Smad3 and Smad4 in TGF-beta-stimulated COL1A2 transcription in human skin fibroblasts in vitro. Furthermore, using transfections with a series of 5' deletions of the human COL1A2 promoter, we identify a proximal region between -353 and -148 bp, which is required for full stimulation of transcription by a constitutively active TGF-beta type I receptor. This region of the COL1A2 promoter contains a CAGA motif also found in the promoter of the plasminogen activator inhibitor-1. Substitutions disrupting this sequence decreased the binding of nuclear extracts or recombinant Smad3 to the CAGACA oligonucleotide, and markedly reduced the transcriptional response to TGF-beta or overexpressed Smad3 in transient transfection assays. The insertion of tandem repeats of CAGACA conferred TGF-beta stimulation to a heterologous minimal promoter-reporter construct. Inhibition of endogenous Smad expression in fibroblasts by antisense oligonucleotides or cDNA against Smad3 or Smad4, and transfection of COL1A2 promoter constructs into Smad4-deficient breast adenocarcinoma cells, indicated the critical role of Smads for the full TGF-beta response. The importance of Smad binding to the CAGACA box of COL1A2 was further established by transcriptional decoy oligonucleotide competition. Taken together, the results identify a functional Smad-binding element of the COL1A2 promoter harboring a CAGACA consensus sequence that is both necessary and sufficient for stimulation by TGF-beta, and demonstrate that interaction of this Smad-binding element with endogenous Smads is required for the full TGF-beta response in fibroblasts.
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Affiliation(s)
- S J Chen
- Section of Rheumatology, University of Illinois College of Medicine at Chicago, Chicago, Illinois 60607-7171, USA
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Zhao J, Crowe DL, Castillo C, Wuenschell C, Chai Y, Warburton D. Smad7 is a TGF-beta-inducible attenuator of Smad2/3-mediated inhibition of embryonic lung morphogenesis. Mech Dev 2000; 93:71-81. [PMID: 10781941 DOI: 10.1016/s0925-4773(00)00281-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Smad7 was recently shown to antagonize TGF-beta-induced activation of signal-transducing Smad2 and Smad3 proteins. However, the biological function of Smad7 in the process of lung organogenesis is not known. Since Smad2/3-mediated TGF-beta signaling is known to inhibit embryonic lung branching morphogenesis, we tested the hypothesis that Smad7 regulates early lung development by modulating TGF-beta signal transduction. An antisense oligodeoxynucleotide (ODN) was designed to specifically block endogenous Smad7 gene expression at both transcriptional and translational levels in embryonic mouse lungs in culture. TGF-beta-mediated inhibition of lung branching morphogenesis was significantly potentiated in cultured embryonic lungs in the absence of Smad7 gene expression: abrogation of Smad7 potentiated TGF-beta-mediated inhibition of lung branching morphogenesis from 76 to 52% of the basal level in lungs cultured in the presence of 5 ng/ml TGF-beta1 ligand. Likewise, TGF-beta1 EC(50) (concentration of TGF-beta1 that induced half maximal branching inhibition) was reduced from 5 to 1 ng/ml when Smad7 gene expression was abrogated in lung culture, indicating an enhanced level of TGF-beta signaling in lung tissue with abolished Smad7 gene expression. By immunocytochemistry, Smad7 protein was co-localized with both Smad2 and Smad3 in distal bronchial epithelial cells, supporting the concept that Smad7 inhibits TGF-beta signaling by competing locally with Smad2 and Smad3 for TGF-beta receptor complex binding during lung morphogenesis. Furthermore, antisense Smad7 ODN increased the negative effect of TGF-beta1 on epithelial cell growth in developing lungs in culture. We also demonstrated that Smad7 mRNA levels were rapidly and potently induced upon TGF-beta1 stimulation of lungs in culture, suggesting that Smad7 regulates TGF-beta responses in a negative feedback loop. These studies define a novel function for Smad7 as an intracellular antagonist of TGF-beta-induced, Smad2/3-mediated inhibition of murine embryonic lung growth and branching morphogenesis in culture. The optimization of TGF-beta signaling during early lung development therefore requires a finely-regulated competitive balance between both permissive and inhibitory members of the Smad family.
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Affiliation(s)
- J Zhao
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles 90033, USA.
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Liu J, Tseu I, Wang J, Tanswell K, Post M. Transforming growth factor beta2, but not beta1 and beta3, is critical for early rat lung branching. Dev Dyn 2000; 217:343-60. [PMID: 10767079 DOI: 10.1002/(sici)1097-0177(200004)217:4<343::aid-dvdy2>3.0.co;2-f] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mesenchymal-epithelial tissue interactions are critical for lung branching morphogenesis, and polypeptide growth factors are likely involved in these tissue interactions. Transforming growth factorbetas (TGFbetas) have been implicated in lung development, but their involvement in early lung branching morphogenesis is unclear. In the present study, we investigated the role of the three mammalian TGFbeta subtypes (beta1, beta2, and beta3) and their receptors (type III (TbetaR-III), type II (TbetaR-II), and two types I (TbetaR-I), ALK-1 and ALK-5) in early rat lung organogenesis by using an embryonic rat lung explant culture. Transcripts and proteins for all three TGFbetas and their receptors were detected during the embryonic period of fetal rat lung development. Inhibition of TGFbeta2, but not beta1 and beta3, with antisense oligonucleotides and neutralizing antibodies resulted in significant inhibition of early lung branching in culture. Addition of minute amounts (</=1 ng/ml) of exogenous TGFbeta2, but not beta1 and beta3, restored the branching of TGFbeta2 antisense-treated explants. Higher concentrations of TGFbeta2 were inhibitory. BrdU labeling of lung explants was not altered by antisense TGFbeta2 treatment, but low concentrations of TGFbeta2 increased thymidine uptake by isolated epithelial cells. Fibronectin and metallogelatinase activities of embryonic lung cells were not affected by any TGFbeta isoform but TGFbeta2 specifically decreased mesenchymal hyaluronan synthesis. Antisense inhibition of ALK-5 and TbetaR-II showed a similar reduction in early lung branching as observed with antisense TGFbeta2. Incubation of lung explants with soluble TbetaR-II receptors also abrogated lung branching. ALK-1 antisense treatment did not affect early branching. Administration of neither activin A, which can act via ALK-1, nor follistatin, the natural inhibitor of activin, to the explants cultures had any significant effect on lung branching. Antisense inhibition of the activin receptor-II (Act-RII) also did not affect lung branching. These results are consistent with TGFbeta2, but not beta1 and beta3, regulating pattern formation during early rat lung organogenesis. This TGFbeta signaling in rat lung branching in vitro appears to be predominantly mediated via the TbetaR-I(ALK-5)/TbetaR-II heteromeric complex.
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Affiliation(s)
- J Liu
- The Medical Research Council Group in Lung Development, Hospital for Sick Children Research Institute's Lung Biology Program, Department of Paediatrics, University of Toronto, Toronto, Canada
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50
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Liu J, Tseu I, Wang J, Tanswell K, Post M. Transforming growth factor ?2, but not ?1 and ?3, is critical for early rat lung branching. Dev Dyn 2000. [DOI: 10.1002/(sici)1097-0177(200004)217:4%3c343::aid-dvdy2%3e3.0.co;2-f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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