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Goldman J, Liu SQ, Tefft BJ. Anti-Inflammatory and Anti-Thrombogenic Properties of Arterial Elastic Laminae. Bioengineering (Basel) 2023; 10:bioengineering10040424. [PMID: 37106611 PMCID: PMC10135563 DOI: 10.3390/bioengineering10040424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 03/07/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Elastic laminae, an elastin-based, layered extracellular matrix structure in the media of arteries, can inhibit leukocyte adhesion and vascular smooth muscle cell proliferation and migration, exhibiting anti-inflammatory and anti-thrombogenic properties. These properties prevent inflammatory and thrombogenic activities in the arterial media, constituting a mechanism for the maintenance of the structural integrity of the arterial wall in vascular disorders. The biological basis for these properties is the elastin-induced activation of inhibitory signaling pathways, involving the inhibitory cell receptor signal regulatory protein α (SIRPα) and Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP1). The activation of these molecules causes deactivation of cell adhesion- and proliferation-regulatory signaling mechanisms. Given such anti-inflammatory and anti-thrombogenic properties, elastic laminae and elastin-based materials have potential for use in vascular reconstruction.
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2
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Procknow SS, Kozel BA. Emerging mechanisms of elastin transcriptional regulation. Am J Physiol Cell Physiol 2022; 323:C666-C677. [PMID: 35816641 PMCID: PMC9448287 DOI: 10.1152/ajpcell.00228.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/06/2022] [Accepted: 07/06/2022] [Indexed: 11/22/2022]
Abstract
Elastin provides recoil to tissues that stretch such as the lung, blood vessels, and skin. It is deposited in a brief window starting in the prenatal period and extending to adolescence in vertebrates, and then slowly turns over. Elastin insufficiency is seen in conditions such as Williams-Beuren syndrome and elastin-related supravalvar aortic stenosis, which are associated with a range of vascular and connective tissue manifestations. Regulation of the elastin (ELN) gene occurs at multiple levels including promoter activation/inhibition, mRNA stability, interaction with microRNAs, and alternative splicing. However, these mechanisms are incompletely understood. Better understanding of the processes controlling ELN gene expression may improve medicine's ability to intervene in these rare conditions, as well as to replace age-associated losses by re-initiating elastin production. This review describes what is known about the ELN gene promoter structure, transcriptional regulation by cytokines and transcription factors, and posttranscriptional regulation via mRNA stability and micro-RNA and highlights new approaches that may influence regenerative medicine.
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Affiliation(s)
- Sara S Procknow
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Beth A Kozel
- Translational Vascular Medicine Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
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3
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Abstract
This biography of Dr. Joel Rosenbloom is published on the occasion of the 50th anniversary of the journal. Dr. Rosenbloom presents the scientific milestones and achievements throughout his career emphasizing events that have spurred him to launch into a career in biomedical research and education. The biography spans several decades of the life and achievements of a distinguished physician scientist whose dedication to science demonstrates the development of new insights into a variety of connective tissues through technological advances and insightful approaches.
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Affiliation(s)
- Joel Rosenbloom
- Joan and Joel Research Center for Fibrotic Diseases, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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4
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Wang B, Patkar SS, Kiick KL. Application of Thermoresponsive Intrinsically Disordered Protein Polymers in Nanostructured and Microstructured Materials. Macromol Biosci 2021; 21:e2100129. [PMID: 34145967 PMCID: PMC8449816 DOI: 10.1002/mabi.202100129] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/25/2021] [Indexed: 01/15/2023]
Abstract
Modulation of inter- and intramolecular interactions between bioinspired designer molecules can be harnessed for developing functional structures that mimic the complex hierarchical organization of multicomponent assemblies observed in nature. Furthermore, such multistimuli-responsive molecules offer orthogonal tunability for generating versatile multifunctional platforms via independent biochemical and biophysical cues. In this review, the remarkable physicochemical and mechanical properties of genetically engineered protein polymers derived from intrinsically disordered proteins, specifically elastin and resilin, are discussed. This review highlights emerging technologies which use them as building blocks in the fabrication of highly programmable structured biomaterials for applications in delivery of biotherapeutic cargo and regenerative medicine.
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Affiliation(s)
- Bin Wang
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont Hall, Newark, DE, 19716, USA
| | - Sai S Patkar
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont Hall, Newark, DE, 19716, USA
| | - Kristi L Kiick
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont Hall, Newark, DE, 19716, USA
- Department of Biomedical Engineering, University of Delaware, 161 Colburn Laboratory, Newark, DE, 19716, USA
- Delaware Biotechnology Institute, Ammon Pinizzotto Biopharmaceutical Innovation Center, 590 Avenue 1743, Newark, DE, 19713, USA
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5
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Ozsvar J, Yang C, Cain SA, Baldock C, Tarakanova A, Weiss AS. Tropoelastin and Elastin Assembly. Front Bioeng Biotechnol 2021; 9:643110. [PMID: 33718344 PMCID: PMC7947355 DOI: 10.3389/fbioe.2021.643110] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/08/2021] [Indexed: 12/12/2022] Open
Abstract
Elastic fibers are an important component of the extracellular matrix, providing stretch, resilience, and cell interactivity to a broad range of elastic tissues. Elastin makes up the majority of elastic fibers and is formed by the hierarchical assembly of its monomer, tropoelastin. Our understanding of key aspects of the assembly process have been unclear due to the intrinsic properties of elastin and tropoelastin that render them difficult to study. This review focuses on recent developments that have shaped our current knowledge of elastin assembly through understanding the relationship between tropoelastin’s structure and function.
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Affiliation(s)
- Jazmin Ozsvar
- Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Chengeng Yang
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT, United States
| | - Stuart A Cain
- Wellcome Trust Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | - Clair Baldock
- Wellcome Trust Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | - Anna Tarakanova
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT, United States.,Department of Mechanical Engineering, University of Connecticut, Storrs, CT, United States
| | - Anthony S Weiss
- Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.,Sydney Nano Institute, The University of Sydney, Sydney, NSW, Australia
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6
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Saey V, Decloedt A, Van Poucke M, Peelman L, van Loon G, Vanderperren K, Ducatelle R, Chiers K. Aortopulmonary fistula in a Warmblood mare associated with an aortic aneurysm and supravalvular aortic stenosis. J Vet Intern Med 2020; 34:2152-2157. [PMID: 32926466 PMCID: PMC7517844 DOI: 10.1111/jvim.15893] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 08/09/2020] [Accepted: 08/18/2020] [Indexed: 12/18/2022] Open
Abstract
This case report describes the clinical presentation, the necropsy findings, and genetic results of a 13-year-old Warmblood mare presented with colic and a bilaterally loud, holosystolic murmur. Echocardiographic examination revealed the presence of a thoracic aortic aneurysm, an aortic pseudoaneurysm, a periaortic hematoma (circumferential cuffing by perivascular hemorrhage), and aortopulmonary fistulation. A supravalvular aortic stenosis (SVAS) was visible during echocardiography. Necropsy confirmed that the thoracic aortic aneurysm had ruptured and connected to the pseudoaneurysm, which fistulated into the pulmonary artery. Histologically, the aneurysm wall revealed chronic lesions such as fibrosis, mucin depositions, mineralizations, and elastin fragmentation. The mid abdominal aorta showed lesions suggestive of a systemic elastin arteriopathy. Molecular analysis, however, could not attribute this disease to a variant in the elastin gene, the most common causative gene for SVAS. To the authors' knowledge, this case report describes a case of aortopulmonary fistulation in a Warmblood horse associated with the presence of SVAS and an aortic aneurysm.
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Affiliation(s)
- Veronique Saey
- Department of Veterinary Pathology, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Annelies Decloedt
- Department of Large Animal Internal Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Mario Van Poucke
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Luc Peelman
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Gunther van Loon
- Department of Large Animal Internal Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Katrien Vanderperren
- Department of Veterinary Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Richard Ducatelle
- Department of Veterinary Pathology, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Koen Chiers
- Department of Veterinary Pathology, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
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Abstract
Elastic fibers are found in the extracellular matrix (ECM) of tissues requiring resilience and depend on elasticity. Elastin and its degradation products have multiple roles in the oncologic process. In many malignancies, the remodeled ECM expresses high levels of the elastin protein which may have either positive or negative effects on tumor growth. Elastin cross-linking with other ECM components and the enzymes governing this process all have effects on tumorigenesis. Elastases, and specifically neutrophil elastase, are key drivers of invasion and metastasis and therefore are important targets for inhibition. Elastin degradation leads to the generation of bioactive fragments and elastin-derived peptides that further modulate tumor growth and spread. Interestingly, elastin-like peptides (ELP) and elastin-derived peptides (EDP) may also be utilized as nano-carriers to combat tumor growth. EDPs drive tumor development in a variety of ways, and specifically targeting EDPs and their binding proteins are major objectives for ongoing and future anti-cancer therapies. Research on both the direct anti-cancer activity and the drug delivery capabilities of ELPs is another area likely to result in novel therapeutic agents in the near future.
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8
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Vindin H, Mithieux SM, Weiss AS. Elastin architecture. Matrix Biol 2019; 84:4-16. [DOI: 10.1016/j.matbio.2019.07.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 07/08/2019] [Accepted: 07/08/2019] [Indexed: 11/15/2022]
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Cocciolone AJ, Hawes JZ, Staiculescu MC, Johnson EO, Murshed M, Wagenseil JE. Elastin, arterial mechanics, and cardiovascular disease. Am J Physiol Heart Circ Physiol 2018; 315:H189-H205. [PMID: 29631368 DOI: 10.1152/ajpheart.00087.2018] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Large, elastic arteries are composed of cells and a specialized extracellular matrix that provides reversible elasticity and strength. Elastin is the matrix protein responsible for this reversible elasticity that reduces the workload on the heart and dampens pulsatile flow in distal arteries. Here, we summarize the elastin protein biochemistry, self-association behavior, cross-linking process, and multistep elastic fiber assembly that provide large arteries with their unique mechanical properties. We present measures of passive arterial mechanics that depend on elastic fiber amounts and integrity such as the Windkessel effect, structural and material stiffness, and energy storage. We discuss supravalvular aortic stenosis and autosomal dominant cutis laxa-1, which are genetic disorders caused by mutations in the elastin gene. We present mouse models of supravalvular aortic stenosis, autosomal dominant cutis laxa-1, and graded elastin amounts that have been invaluable for understanding the role of elastin in arterial mechanics and cardiovascular disease. We summarize acquired diseases associated with elastic fiber defects, including hypertension and arterial stiffness, diabetes, obesity, atherosclerosis, calcification, and aneurysms and dissections. We mention animal models that have helped delineate the role of elastic fiber defects in these acquired diseases. We briefly summarize challenges and recent advances in generating functional elastic fibers in tissue-engineered arteries. We conclude with suggestions for future research and opportunities for therapeutic intervention in genetic and acquired elastinopathies.
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Affiliation(s)
- Austin J Cocciolone
- Department of Biomedical Engineering, Washington University , St. Louis, Missouri
| | - Jie Z Hawes
- Department of Mechanical Engineering and Materials Science, Washington University , St. Louis, Missouri
| | - Marius C Staiculescu
- Department of Mechanical Engineering and Materials Science, Washington University , St. Louis, Missouri
| | - Elizabeth O Johnson
- Department of Mechanical Engineering and Materials Science, Washington University , St. Louis, Missouri
| | - Monzur Murshed
- Faculty of Dentistry, Department of Medicine, and Shriners Hospital for Children, McGill University , Montreal, Quebec , Canada
| | - Jessica E Wagenseil
- Department of Mechanical Engineering and Materials Science, Washington University , St. Louis, Missouri
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10
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Yeo J, Jung G, Tarakanova A, Martín-Martínez FJ, Qin Z, Cheng Y, Zhang YW, Buehler MJ. Multiscale modeling of keratin, collagen, elastin and related human diseases: Perspectives from atomistic to coarse-grained molecular dynamics simulations. EXTREME MECHANICS LETTERS 2018; 20:112-124. [PMID: 33344740 PMCID: PMC7745951 DOI: 10.1016/j.eml.2018.01.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Scleroproteins are an important category of proteins within the human body that adopt filamentous, elongated conformations in contrast with typical globular proteins. These include keratin, collagen, and elastin, which often serve a common mechanical function in structural support of cells and tissues. Genetic mutations alter these proteins, disrupting their functions and causing diseases. Computational characterization of these mutations has proven to be extremely valuable in identifying the intricate structure-function relationships of scleroproteins from the molecular scale up, especially if combined with multiscale experimental analysis and the synthesis of model proteins to test specific structure-function relationships. In this work, we review numerous critical diseases that are related to keratin, collagen, and elastin, and through several case studies, we propose ways of extensively utilizing multiscale modeling, from atomistic to coarse-grained molecular dynamics simulations, to uncover the molecular origins for some of these diseases and to aid in the development of novel cures and therapies. As case studies, we examine the effects of the genetic disease Epidermolytic Hyperkeratosis (EHK) on the structure and aggregation of keratins 1 and 10; we propose models to understand the diseases of Osteogenesis Imperfecta (OI) and Alport syndrome (AS) that affect the mechanical and aggregation properties of collagen; and we develop atomistic molecular dynamics and elastic network models of elastin to determine the role of mutations in diseases such as Cutis Laxa and Supravalvular Aortic Stenosis on elastin's structure and molecular conformational motions and implications for assembly.
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Affiliation(s)
- Jingjie Yeo
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Institute of High Performance Computing, Agency for Science, Technology and Research (A*STAR), Singapore 138632
| | - GangSeob Jung
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anna Tarakanova
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Francisco J. Martín-Martínez
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Zhao Qin
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yuan Cheng
- Institute of High Performance Computing, Agency for Science, Technology and Research (A*STAR), Singapore 138632
| | - Yong-Wei Zhang
- Institute of High Performance Computing, Agency for Science, Technology and Research (A*STAR), Singapore 138632
| | - Markus J. Buehler
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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11
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Angel PM, Comte-Walters S, Ball LE, Talbot K, Mehta A, Brockbank KGM, Drake RR. Mapping Extracellular Matrix Proteins in Formalin-Fixed, Paraffin-Embedded Tissues by MALDI Imaging Mass Spectrometry. J Proteome Res 2017; 17:635-646. [PMID: 29161047 DOI: 10.1021/acs.jproteome.7b00713] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Collagens and elastin form the fundamental framework of all tissues and organs, and their expression and post-translational processing are tightly regulated in disease and health. Because of their unique structural composition and properties, it is a recognized challenge to access these protein structures within the complex tissue microenvironment to understand how localized changes modulate tissue health. We describe a new workflow using a combination of matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) with matrix metalloproteinase (MMP) enzymes to access and report on spatial localization of collagen and elastin sequences in formalin-fixed, paraffin-embedded (FFPE) tissues. The developed technology provides new access to collagens and elastin sequences localized to tissue features that were previously unattainable. This high-throughput technological advance should be applicable to any tissue regardless of disease type, tissue origin, or disease status and is thus relevant to all research: basic, translational, or clinical.
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Affiliation(s)
| | | | | | | | | | - Kelvin G M Brockbank
- Tissue Testing Technologies LLC , North Charleston, South Carolina 29406, United States.,Department of Bioengineering, Clemson University , Clemson, South Carolina 29634, United States
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12
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Single nucleotide polymorphisms and domain/splice variants modulate assembly and elastomeric properties of human elastin. Implications for tissue specificity and durability of elastic tissue. Biopolymers 2017; 107. [DOI: 10.1002/bip.23007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/23/2016] [Accepted: 12/03/2016] [Indexed: 12/13/2022]
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13
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Miranda-Nieves D, Chaikof EL. Collagen and Elastin Biomaterials for the Fabrication of Engineered Living Tissues. ACS Biomater Sci Eng 2016; 3:694-711. [PMID: 33440491 DOI: 10.1021/acsbiomaterials.6b00250] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Collagen and elastin represent the two most predominant proteins in the body and are responsible for modulating important biological and mechanical properties. Thus, the focus of this review is the use of collagen and elastin as biomaterials for the fabrication of living tissues. Considering the importance of both biomaterials, we first propose the notion that many tissues in the human body represent a reinforced composite of collagen and elastin. In the rest of the review, collagen and elastin biosynthesis and biophysics, as well as molecular sources and biomaterial fabrication methodologies, including casting, fiber spinning, and bioprinting, are discussed. Finally, we summarize the current attempts to fabricate a subset of living tissues and, based on biochemical and biomechanical considerations, suggest that future tissue-engineering efforts consider direct incorporation of collagen and elastin biomaterials.
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Affiliation(s)
- David Miranda-Nieves
- Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.,Department of Surgery, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, United States
| | - Elliot L Chaikof
- Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.,Department of Surgery, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, United States.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02215, United States
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14
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Yeo GC, Tarakanova A, Baldock C, Wise SG, Buehler MJ, Weiss AS. Subtle balance of tropoelastin molecular shape and flexibility regulates dynamics and hierarchical assembly. SCIENCE ADVANCES 2016; 2:e1501145. [PMID: 26998516 PMCID: PMC4795673 DOI: 10.1126/sciadv.1501145] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 11/20/2015] [Indexed: 05/02/2023]
Abstract
The assembly of the tropoelastin monomer into elastin is vital for conferring elasticity on blood vessels, skin, and lungs. Tropoelastin has dual needs for flexibility and structure in self-assembly. We explore the structure-dynamics-function interplay, consider the duality of molecular order and disorder, and identify equally significant functional contributions by local and global structures. To study these organizational stratifications, we perturb a key hinge region by expressing an exon that is universally spliced out in human tropoelastins. We find a herniated nanostructure with a displaced C terminus and explain by molecular modeling that flexible helices are replaced with substantial β sheets. We see atypical higher-order cross-linking and inefficient assembly into discontinuous, thick elastic fibers. We explain this dysfunction by correlating local and global structural effects with changes in the molecule's assembly dynamics. This work has general implications for our understanding of elastomeric proteins, which balance disordered regions with defined structural modules at multiple scales for functional assembly.
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Affiliation(s)
- Giselle C. Yeo
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales 2006, Australia
- School of Molecular Bioscience, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Anna Tarakanova
- Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Clair Baldock
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Steven G. Wise
- The Heart Research Institute, Newtown, New South Wales 2050, Australia
| | - Markus J. Buehler
- Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Anthony S. Weiss
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales 2006, Australia
- School of Molecular Bioscience, The University of Sydney, Sydney, New South Wales 2006, Australia
- Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
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15
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Weiss AS. Perspectives on the Molecular and Biological Implications of Tropoelastin in Human Tissue Elasticity. Aust J Chem 2016. [DOI: 10.1071/ch16452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The elasticity of a range of vertebrate and particularly human tissues depends on the dynamic and persistent protein elastin. This elasticity is diverse, and comprises skin, blood vessels, and lung, and is essential for tissue viability. Elastin is predominantly made by assembling tropoelastin, which is an asymmetric 20-nm-long protein molecule. This overview considers tropoelastin’s molecular features and biological interactions in the context of its value in tissue repair.
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Abstract
Supravalvular aortic aneurysms are less frequent than abdominal ones. Among Supravalvular aortic aneurysm aetiologies, we focused on dystrophic lesions as they can be secondary to genetic causes such as elastin anomaly. We report on a familial 7q11.23 triplication - including the ELN gene - segregating with a supravalvular aortic aneurysm. During her first pregnancy, our index patient was diagnosed with tuberous sclerosis and with a Supravalvular aortic aneurysm. The foetus was affected equally. For the second pregnancy, parents applied for preimplantation diagnosis, and a subsequent prenatal diagnosis was offered to the couple, comprising TSC1 molecular analysis, karyotype, and multiplex ligation probe amplification. TSC1 mutation was not found on foetal deoxyribo nucleic acid. Foetal karyotype was normal, but multiplex ligation probe amplification detected a 7q11.23 duplication. Quantitative-polymerase chain reaction and array-comparative genomic hybridisation carried out to further assess this chromosome imbalance subsequently identified a 7q11.23 triplication involving ELN and LIMK1. Foetal heart ultrasound identified a Supravalvular aortic aneurysm. A familial screening was offered for the 7q11.23 triplication and, when found, heart ultrasound was performed. The triplication was diagnosed in our index case as well as in her first child. Of the 17 individuals from this family, 11 have the triplication. Of the 11 individuals with the triplication, 10 were identified to have a supravalvular aortic aneurysm. Of them, two individuals received a medical treatment and one individual needed surgery. We provide evidence of supravalvular aortic aneurysm segregating with 7q11.23 triplication in this family. We would therefore recommend cardiac surveillance for individuals with 7q11.23 triplication. It would also be interesting to offer a quantitative-polymerase chain reaction or an array-comparative genomic hybridisation to a larger cohort of patients presenting with isolated supravalvular aortic aneurysm, as it may provide further information.
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17
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Yang J, Zhao HL, Tang BL, Chen XL, Su HN, Zhang XY, Song XY, Zhou BC, Xie BB, Weiss AS, Zhang YZ. Mechanistic insight into the elastin degradation process by the metalloprotease myroilysin from the deep-sea bacterium Myroides profundi D25. Mar Drugs 2015; 13:1481-96. [PMID: 25793427 PMCID: PMC4377995 DOI: 10.3390/md13031481] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/10/2015] [Indexed: 02/01/2023] Open
Abstract
Elastases have been widely studied because of their important uses as medicine and meat tenderizers. However, there are relatively few studies on marine elastases. Myroilysin, secreted by Myroides profundi D25 from deep-sea sediment, is a novel elastase. In this study, we examined the elastin degradation mechanism of myroilysin. When mixed with insoluble bovine elastin, myroilysin bound hydrophobically, suggesting that this elastase may interact with the hydrophobic domains of elastin. Consistent with this, analysis of the cleavage pattern of myroilysin on bovine elastin and recombinant tropoelastin revealed that myroilysin preferentially cleaves peptide bonds with hydrophobic residues at the P1 and/or P1′ positions. Scanning electron microscopy (SEM) of cross-linked recombinant tropoelastin degraded by myroilysin showed preferential damages of spherules over cross-links, as expected for a hydrophobic preference. The degradation process of myroilysin on bovine elastin fibres was followed by light microscopy and SEM, revealing that degradation begins with the formation of crevices and cavities at the fibre surface, with these openings increasing in number and size until the fibre breaks into small pieces, which are subsequently fragmented. Our results are helpful for developing biotechnological applications for myroilysin.
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Affiliation(s)
- Jie Yang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
| | - Hui-Lin Zhao
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Department of Pathogenic Biology, Binzhou Medical University, Shandong Province, Yantai 264003, China.
| | - Bai-Lu Tang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
| | - Hai-Nan Su
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
| | - Xi-Ying Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
| | - Xiao-Yan Song
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
| | - Bai-Cheng Zhou
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
| | - Bin-Bin Xie
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
| | - Anthony S Weiss
- School of Molecular Bioscience, The University of Sydney, NSW 2006, Australia.
| | - Yu-Zhong Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
- Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
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18
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Abstract
Matrikines originate from the fragmentation of extracellular matrix proteins and regulate cellular activities by interacting with specific receptors. Matrikines are implicated in inflammation, immune responses, organ development, wound repair, angiogenesis, atherosclerosis, tumor progression and metastasis due to their ability to alter cellular migration, chemotaxis, and mitogenesis. Matrix metalloproteinases (MMPs) degrade extracellular matrix components under normal circumstances and in disease processes. Of the 20 MMPs identified, MMP-1, MMP-2, MMP-8, MMP-9, and MMP-12 have been implicated in regulating the matrikines Val-Gly-Val-Ala-Pro-Gly (elastin peptide) and proline-glycine-proline (PGP). Elastin peptide fragments are generated by elastolytic enzymes and have implications in atherosclerosis, neovascularization, chronic obstructive pulmonary disease, skin disease, as well as tumor invasion and spread. PGP is produced through a multistep pathway that liberates the tripeptide fragment from extracellular collagen. PGP is best described for its role in neutrophil chemotaxis and is implicated in the pathogenesis of corneal ulcers and in chronic lung conditions. In chronic cigarette smoke related lung disease, the PGP pathway can become a self-propagating cycle of inflammation through cigarette-smoke mediated inhibition of leukotriene A4 hydrolase, the enzyme responsible for degrading PGP and halting acute inflammation. This review highlights the roles of MMPs in generating these important matrikines.
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Yeo GC, Baldock C, Wise SG, Weiss AS. A negatively charged residue stabilizes the tropoelastin N-terminal region for elastic fiber assembly. J Biol Chem 2014; 289:34815-26. [PMID: 25342751 PMCID: PMC4263881 DOI: 10.1074/jbc.m114.606772] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/21/2014] [Indexed: 01/16/2023] Open
Abstract
Tropoelastin is an extracellular matrix protein that assembles into elastic fibers that provide elasticity and strength to vertebrate tissues. Although the contributions of specific tropoelastin regions during each stage of elastogenesis are still not fully understood, studies predominantly recognize the central hinge/bridge and C-terminal foot as the major participants in tropoelastin assembly, with a number of interactions mediated by the abundant positively charged residues within these regions. However, much less is known about the importance of the rarely occurring negatively charged residues and the N-terminal coil region in tropoelastin assembly. The sole negatively charged residue in the first half of human tropoelastin is aspartate 72. In contrast, the same region comprises 17 positively charged residues. We mutated this aspartate residue to alanine and assessed the elastogenic capacity of this novel construct. We found that D72A tropoelastin has a decreased propensity for initial self-association, and it cross-links aberrantly into denser, less porous hydrogels with reduced swelling properties. Although the mutant can bind cells normally, it does not form elastic fibers with human dermal fibroblasts and forms fewer atypical fibers with human retinal pigmented epithelial cells. This impaired functionality is associated with conformational changes in the N-terminal region. Our results strongly point to the role of the Asp-72 site in stabilizing the N-terminal segment of human tropoelastin and the importance of this region in facilitating elastic fiber assembly.
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Affiliation(s)
- Giselle C Yeo
- From the School of Molecular Bioscience and Charles Perkins Centre, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Clair Baldock
- the Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Steven G Wise
- the Heart Research Institute, Sydney, New South Wales 2042, Australia, and the Sydney Medical School and
| | - Anthony S Weiss
- From the School of Molecular Bioscience and Charles Perkins Centre, University of Sydney, Sydney, New South Wales 2006, Australia, Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
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20
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Kaneoya K, Momota Y, Hatamochi A, Matsumoto F, Arima Y, Miyachi Y, Shinkai H, Utani A. Elastin Gene Expression in Blepharochalasis. J Dermatol 2014; 32:26-9. [PMID: 15841657 DOI: 10.1111/j.1346-8138.2005.tb00709.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Blepharochalasis is a rare condition characterized by recurrent episodes of eyelid edema lead to an atrophic eyelid skin with fine wrinkles and peculiar bronze discoloration. A 32-year-old female presented with loose and redundant skin of the bilateral eyelids. We diagnosed her disease as blepharochalasis by clinical features and by disappearance of elastic fibers from the dermis in the biopsied specimen. Because elastic fibers diminish in the late phase of blepharochalasis, we performed RT-PCR to analyze the mRNA expression of elastin, a major component of elastic fiber. Elastin mRNA expression in the patient's cultured fibroblasts had not decreased compared with that in the control fibroblasts. This result suggests that environmental factors or other matrix components of elastic fibers may be involved in the loss of elastic fiber.
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Affiliation(s)
- Kyoko Kaneoya
- Department of Dermatology, Chiba University School of Medicine, Chiba, Japan
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21
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22
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Cheung KLY, Bates M, Ananthanarayanan VS. Effect of FKBP65, a putative elastin chaperone, on the coacervation of tropoelastin in vitro. Biochem Cell Biol 2011; 88:917-25. [PMID: 21102654 DOI: 10.1139/o10-137] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
FKBP65 is a protein of the endoplasmic reticulum that is relatively abundant in elastin-producing cells and is associated with tropoelastin in the secretory pathway. To test an earlier suggestion by Davis and co-workers that FKBP65 could act as an intracellular chaperone for elastin, we obtained recombinant FKBP65 (rFKBP65) by expressing it in E. coli and examined its effect on the coacervation characteristics of chicken aorta tropoelastin (TE) using an in vitro turbidimetric assay. Our results reveal that rFKBP65 markedly promotes the initiation of coacervation of TE without significantly affecting the temperature of onset of coacervation. This effect shows saturation at a 1:2 molar ratio of TE to rFKBP65. By contrast, FKBP12, a peptidyl prolyl isomerase, has a negligible effect on TE coacervation. Moreover, the effect of rFKBP65 on TE coacervation is unaffected by the addition of rapamycin, an inhibitor of peptidyl prolyl isomerase (PPIase) activity. These observations rule out the involvement of the PPIase activity of rFKBP65 in modulating the coacervation of TE. Additional experiments using a polypeptide model of TE showed that rFKBP65, while promoting coacervation, may retard the maturation of this model polypeptide into larger aggregates. Based on these results, we suggest that FKBP65 may act as an elastin chaperone in vivo by controlling both the coacervation and the maturation stages of its self-assembly into fibrils.
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Affiliation(s)
- Kevin L Y Cheung
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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23
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Chen Z, Shin MH, Moon YJ, Lee SR, Kim YK, Seo JE, Kim JE, Kim KH, Chung JH. Modulation of elastin exon 26A mRNA and protein expression in human skinin vivo. Exp Dermatol 2009; 18:378-86. [DOI: 10.1111/j.1600-0625.2008.00799.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Rosenbloom J, Abrams WR, Indik Z, Yeh H, Ornstein-Goldstein N, Bashir MM. Structure of the elastin gene. CIBA FOUNDATION SYMPOSIUM 2007; 192:59-74; discussion 74-80. [PMID: 8575268 DOI: 10.1002/9780470514771.ch4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The isolation and characterization of cDNAs encompassing the full length of chicken, cow, rat and human elastin mRNA have led to the elucidation of the primary structure of the respective tropoelastins. Large segments of the sequence are conserved but there are also considerable variations which range in extent from relatively small alterations, such as conservative amino acid substitutions, to variation in the length of hydrophobic segments and largescale deletions and insertions. In general, smaller differences are found among mammalian tropoelastins and greater ones between chicken and mammalian tropoelastins. Although only a single elastin gene is found per haploid genome, the primary transcript is subject to considerable alternative splicing, resulting in multiple tropoelastin isoforms. Functionally distinct hydrophobic and cross-link domains of the protein are encoded in separate exons which alternate in the gene. The introns of the human gene are rich in Alu repetitive sequences, which may be the site of recombinational events, and there are also several dinucleotide repeats, which may exhibit polymorphism and, therefore, be effective genetic markers. The 5' flanking region is G+C rich and contains potential binding sites for numerous modulating factors, but no TATA box or functional CAAT box. The basic promoter is contained within a 136 bp segment and transcription is initiated at multiple sites. These findings suggest that the regulation of elastin gene expression is complex and takes place at several levels.
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Affiliation(s)
- J Rosenbloom
- Department of Anatomy and Histology, School of Dental Medicine, University of Pennsylvania, Philadelphia 19104, USA
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25
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Hinek A. The 67 kDa spliced variant of beta-galactosidase serves as a reusable protective chaperone for tropoelastin. CIBA FOUNDATION SYMPOSIUM 2007; 192:185-91; discussion 191-6. [PMID: 8575257 DOI: 10.1002/9780470514771.ch10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Numerous cell types express the 67 kDa galactolectin related to the alternatively spliced variant of beta-galactosidase. This 67 kDa protein, while present on cell surfaces, mediates cell contacts with elastin, laminin and collagen type IV. In elastin-producing tissues, the 67 kDa protein also co-localizes with intracellular tropoelastin and mature elastic fibres. We have established that this elastin binding protein (EBP) serves as a molecular chaperone for tropoelastin. The EBP binds this highly hydrophobic and unglycosylated ligand intracellularly, protecting it from intracellular self aggregation and premature proteolytic degradation, and mediates its orderly assembly upon the microfibrillar scaffold. While some of this protein is incorporated as a permanent component of elastic fibres, most of the EBP, after extracellular dissociation from its ligand, recycles back to the intracellular endosomal compartment and re-associates with the newly synthesized tropoelastin. We suggest that recycling of this reusable shuttle protein is imperative for the effective extracellular deposition of insoluble elastin.
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Affiliation(s)
- A Hinek
- Division of Cardiovascular Research, Hospital for Sick Children, Toronto, Ontario, Canada
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26
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Pierce RA, Mariani TJ, Senior RM. Elastin in lung development and disease. CIBA FOUNDATION SYMPOSIUM 2007; 192:199-212; discussion 212-4. [PMID: 8575258 DOI: 10.1002/9780470514771.ch11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Elastic fibres are present in lung structures including alveoli, alveolar ducts, airways, vasculature and pleura. The rate of lung elastin synthesis is greatest during fetal and neonatal development, and is minimal in the healthy adult. We have determined that glucocorticoids up-regulate fetal lung tropoelastin expression while concomitantly accelerating terminal airspace maturation. Because there is minimal turnover of elastin in healthy adult lung, the elastin incorporated into the lung early in development supports lung function for the normal lifespan. However, in the adult lung, in pathological circumstances such as emphysema or pulmonary fibrosis there may be reactivation of elastin expression. We have found in silica-induced pulmonary fibrosis that expression of tropoelastin is primarily increased in the walls and the septal tips of the alveolus, with modest increases in other compartments which normally express tropoelastin during development. This finding suggests that the mesenchymal cell of the alveolar wall increases tropoelastin expression during fibrotic disorders. In emphysema and fibrosis, elastin is present in abnormal-appearing, probably non-functional, elastic fibres, suggesting that the adult lung cannot recapitulate the elastic fibre assembly mechanisms operative during normal lung growth.
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Affiliation(s)
- R A Pierce
- Division of Dermatology, Washington University School of Medicine, Jewish Hospital, St. Louis, MO 63110, USA
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27
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Uitto J, Hsu-Wong S, Katchman SD, Bashir MM, Rosenbloom J. Skin elastic fibres: regulation of human elastin promoter activity in transgenic mice. CIBA FOUNDATION SYMPOSIUM 2007; 192:237-53; discussion 253-8. [PMID: 8575260 DOI: 10.1002/9780470514771.ch13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Elastic fibres form an extracellular network which provides elasticity and resilience to tissues such as the skin. To study the regulation of human elastin gene expression, we have developed a line of transgenic mice which harbour 5.2 kb of human elastin gene promoter region in their genome. This promoter is linked to the chloramphenicol acetyltransferase (CAT) reporter gene which allows determination of the expression of human elastin promoter in different tissues. The highest CAT activity was found in the lungs and aorta, tissues rich in elastin, while lower levels were detected in a variety of other tissues, including skin. Assay of CAT activity in the lungs of fetal and newborn animals revealed high activity which progressively declined during the postnatal period up to six months. Thus, there was evidence of tissue-specific and developmentally regulated expression of the human elastin promoter activity in these mice. These animals were then used to examine the expression of the elastin gene by a variety of factors which have previously shown to alter elastin gene expression, as determined at the mRNA or protein levels. First, injection of transforming growth factor beta 1 (100 ng) subcutaneously into the transgenic animals resulted in a time-dependent elevation of the promoter activity up to 10-fold after a single injection. Secondly, enhancement of the human elastin promoter activity by interleukin 1 beta injected subcutaneously resulted in an approximately 10-fold elevation of the CAT activity. Finally, subcutaneous injection of these animals with triamcinolone acetonide or dexamethasone, two glucocorticosteroids in clinical use, resulted in marked enhancement of human elastin promoter activity. Similar changes were noted in fibroblast cultures established from the transgenic animals. These data indicate that the 5.2 kb upstream segment of the human elastin gene contains cis-elements which allow tissue-specific and developmentally regulated expression of the human elastin promoter. Furthermore, this segment of the gene contains responsive elements to a variety of cytokines and pharmacological agents. Collectively, these data indicate that elastin gene expression in the skin in vivo can be regulated at the transcriptional level.
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Affiliation(s)
- J Uitto
- Department of Dermatology, Jefferson Medical College, Philadelphia, PA, USA
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28
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Kuang PP, Zhang XH, Rich CB, Foster JA, Subramanian M, Goldstein RH. Activation of elastin transcription by transforming growth factor-beta in human lung fibroblasts. Am J Physiol Lung Cell Mol Physiol 2007; 292:L944-52. [PMID: 17209135 DOI: 10.1152/ajplung.00184.2006] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Elastin synthesis is essential for lung development and postnatal maturation as well as for repair following injury. Using human embryonic lung fibroblasts that express undetectable levels of elastin as assessed by Northern analyses, we found that treatment with exogenous transforming growth factor-beta (TGF-beta) induced rapid and transient increases in levels of elastin heterogeneous nuclear RNA (hnRNA) followed by increases of elastin mRNA and protein expression. In fibroblasts derived from transgenic mice, TGF-beta induced increases in the expression of a human elastin gene promoter fragment driving a chloramphenicol acetyl transferase reporter gene. The induction of elastin hnRNA and mRNA expression by TGF-beta was abolished by pretreatments with TGF-beta receptor I inhibitor, global transcription inhibitor actinomycin D, and partially blocked by addition of protein synthesis inhibitor cycloheximide, but was not affected by the p44/42 MAPK inhibitor U0126. Pretreatment with the p38 MAPK inhibitor SB-203580 also partially attenuated the levels of TGF-beta-induced elastin mRNA but not its hnRNA. Western analysis indicated that TGF-beta stimulated Akt phosphorylation. Inhibition of phosphatidylinositol 3-kinase and Akt phosphorylation by LY-294002 abolished TGF-beta-induced increases in elastin hnRNA and mRNA expression. Treatment of lung fibroblasts with interleukin-1beta or the histone deacetylase inhibitor trichostatin A inhibited TGF-beta-induced elastin mRNA and hnRNA expression by a mechanism that involved inhibition of Akt phosphorylation. Downregulation of Akt2 but not Akt1 expression employing small interfering RNA duplexes blocked TGF-beta-induced increases of elastin hnRNA and mRNA levels. Together, our results demonstrated that TGF-beta activates elastin transcription that is dependent on phosphatidylinositol 3-kinase/Akt activity.
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Affiliation(s)
- Ping-Ping Kuang
- Pulmonary Center, Boston University School of Medicine, 80 E. Concord St., Boston, MA 02118, USA.
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29
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Pierce RA, Moore CH, Arikan MC. Positive transcriptional regulatory element located within exon 1 of elastin gene. Am J Physiol Lung Cell Mol Physiol 2006; 291:L391-9. [PMID: 16899711 DOI: 10.1152/ajplung.00441.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Elastin gene transcription is cell type specific and developmentally regulated, but the promoter often exhibits relatively weak activity in transient transfections of cells that express elastin at high levels. To search for positive-acting regulatory sequences, we isolated genomic clones spanning the mouse elastin gene and extensive 5'- and 3'-flanking regions. Restriction fragments of potential regulatory regions were ligated 5' or 3' relative to the active promoter to test for enhancer activity in transient transfections of fetal rat lung fibroblasts, which express elastin at high levels, and distal lung epithelial cells, which do not express detectable elastin. Fragments of intron 1 did not exhibit significant enhancer activity. Inclusion of the 84-bp exon 1 and adjacent 5'-untranslated region increased activity of the elastin promoter approximately sixfold compared with parental constructs. Transfections with constructs of varying promoter length showed that as little as 40 bp of the 5' end of exon 1 confers enhanced activity in elastin-expressing rat lung fibroblasts, but these constructs had variable activity in lung epithelial cell lines. This region, localized between the transcription start site and extending into exon 1, binds Sp1 in nuclear extracts from elastin-expressing cells. These studies indicate a role for the 5' end of the first exon of the elastin gene in regulating strong transcriptional activity in elastogenic cells.
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Affiliation(s)
- Richard A Pierce
- Division of Pulmonary Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
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30
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Clarke AW, Arnspang EC, Mithieux SM, Korkmaz E, Braet F, Weiss AS. Tropoelastin massively associates during coacervation to form quantized protein spheres. Biochemistry 2006; 45:9989-96. [PMID: 16906757 DOI: 10.1021/bi0610092] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tropoelastin, the precursor of elastin, undergoes a rapid monomer to multimer association in an inverse temperature transition. This association culminates in the rapid formation of stable, optically distinct droplets of tropoelastin. Light scattering and microscope measurements reveal that these droplets are 2-6 microm in diameter. Scanning electron microscopy confirms that the droplets are spherical. Three-dimensional confocal image stacks based on the autofluorescence of tropoelastin reveal that droplets are loaded with hydrated tropoelastin. Droplets are viable intermediates in synthetic elastin macroassembly. Dense clusters of aggregated droplets and partially formed fibers develop when droplets are incubated in the presence of a lysyl oxidase. Lysine-reacting chemical and enzyme-assisted cross-linking conditions generate cross-linked beads due to interactions between multiple, surface-exposed lysine epsilon-amino groups. Droplets represent an efficient mechanism for the bolus delivery during elastogenesis of quantized packages of preaccreted tropoelastin.
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Affiliation(s)
- Adam W Clarke
- School of Molecular and Microbial Biosciences G08, University of Sydney, New South Wales 2006, Australia
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31
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Tamburro AM, Pepe A, Bochicchio B. Localizing alpha-helices in human tropoelastin: assembly of the elastin "puzzle". Biochemistry 2006; 45:9518-30. [PMID: 16878986 DOI: 10.1021/bi060289i] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polyalanine cross-linking domains encoded by exons 6, 15, 17, 19, 21, 23, 25, 27, 29, 31 of human tropoelastin were synthesized, and their conformations were studied in different solutions and at different temperatures by CD and (1)H NMR. The results demonstrated the presence of poly-proline II helix (PPII) in aqueous solvent and of alpha-helical conformation in TFE. The (1)H NMR results allowed the precise localization of the helices along the peptide sequence. These data were further refined by prediction algorithms in order to take into account the reduced helix stability at the end of the peptides. Furthermore, the influence of flanking residues was checked by synthesizing and by determining the structure of a peptide spanning exon 31 coded domain and the first five residues of the following exon 32 coded domain. These studies, together with those previously published [Tamburro, A. M., Bochicchio, B., and Pepe, A. (2003) Biochemistry 42, 13147-62], are used to propose a coherent recomposition of the elastin pieces (domains) in order to give an acceptable solution to the elastin structure-function problem.
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Affiliation(s)
- Antonio Mario Tamburro
- Department of Chemistry, Università degli Studi della Basilicata,Via N. Sauro, 85, 85100 Potenza, Italy.
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32
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Arribas SM, Hinek A, González MC. Elastic fibres and vascular structure in hypertension. Pharmacol Ther 2006; 111:771-91. [PMID: 16488477 DOI: 10.1016/j.pharmthera.2005.12.003] [Citation(s) in RCA: 184] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2005] [Indexed: 01/22/2023]
Abstract
Blood vessels are dynamic structures composed of cells and extracellular matrix (ECM), which are in continuous cross-talk with each other. Thus, cellular changes in phenotype or in proliferation/death rate affect ECM synthesis. In turn, ECM elements not only provide the structural framework for vascular cells, but they also modulate cellular function through specific receptors. These ECM-cell interactions, together with neurotransmitters, hormones and the mechanical forces imposed by the heart, modulate the structural organization of the vascular wall. It is not surprising that pathological states related to alterations in the nervous, humoral or haemodynamic environment-such as hypertension-are associated with vascular wall remodeling, which, in the end, is deleterious for cardiovascular function. However, the question remains whether these structural alterations are simply a consequence of the disease or if there are early cellular or ECM alterations-determined either genetically or by environmental factors-that can predispose to vascular remodeling independent of hypertension. Elastic fibres might be key elements in the pathophysiology of hypertensive vascular remodeling. In addition to the well known effects of hypertension on elastic fibre fatigue and accelerated degradation, leading to loss of arterial wall resilience, recent investigations have highlighted new roles for individual components of elastic fibres and their degradation products. These elements can act as signal transducers and regulate cellular proliferation, migration, phenotype, and ECM degradation. In this paper, we review current knowledge regarding components of elastic fibres and discuss their possible pathomechanistic associations with vascular structural abnormalities and with hypertension development or progression.
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Affiliation(s)
- Silvia M Arribas
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo 2, 28029-Madrid, Spain.
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33
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34
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Wise SG, Mithieux SM, Raftery MJ, Weiss AS. Specificity in the coacervation of tropoelastin: solvent exposed lysines. J Struct Biol 2005; 149:273-81. [PMID: 15721581 DOI: 10.1016/j.jsb.2004.11.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Revised: 11/09/2004] [Indexed: 11/16/2022]
Abstract
Tropoelastin protein monomers associate by coacervation and are cross-linked in vivo to form elastin macro-assemblies. We provide evidence for specific protein domain contact points between tropoelastin monomers during association by coacervation. The homobifunctional cross-linker bis(sulfosuccinimidyl) suberate served as a rapid reporter of adjacent lysines and preferentially exposed domains. Intact cross-linked peptide pairs were identified after protease digestion and high-resolution electrospray mass spectrometry followed by MS/MS sequencing. Mapping of the assigned sequences indicated that the region in the monomer spanning domains 19-25 was readily accessible to solvent and enriched in cross-linking. Domains 12 and 36 were also prevalent, where these two regions were not previously thought to play a major role in the formation of mature elastin. A specificity for particular lysines allowed for the construction of a model for the first close contacts between domains and the first detailed study of the cross-linking of tropoelastin.
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Affiliation(s)
- Steven G Wise
- School of Molecular and Microbial Biosciences, University of Sydney, NSW 2006, Australia
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35
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Rodgers UR, Weiss AS. Cellular interactions with elastin. ACTA ACUST UNITED AC 2005; 53:390-8. [PMID: 16085115 DOI: 10.1016/j.patbio.2004.12.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2004] [Accepted: 12/09/2004] [Indexed: 11/30/2022]
Abstract
Elastin is a key structural component of the extracellular matrix. Tropoelastin is the soluble precursor of elastin. In addition to providing elastic recoil to various tissues such as the aorta and lung, elastin, tropoelastin and elastin degradation products are able to influence cell function and promote cellular responses. These responses include chemotaxis, proliferation and cell adhesion. The interaction of elastin products with cells has been attributed to the elastin receptor. However, additional cell-surface receptors have also been identified. These include G protein-coupled receptors and integrins. The potential roles of these receptors in cell-elastin interactions, with particular focus on elastin formation are discussed.
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Affiliation(s)
- Ursula R Rodgers
- School of Molecular and Microbial Biosciences, University of Sydney, NSW, Australia
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36
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Moroy G, Alix AJP, Héry-Huynh S. Structural characterization of human elastin derived peptides containing the GXXP sequence. Biopolymers 2005; 78:206-20. [PMID: 15812830 DOI: 10.1002/bip.20276] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The degradation of elastin, the insoluble biopolymer of tropoelastin, can lead to the production of small peptides. These elastin-derived peptides (EDPs) are playing a key role in cellular behavior within the extracellular matrix, showing a great variety of biological effects such as chemotaxis, stimulation of cell proliferation, ion flux modifications, vasorelaxation, and inflammatory enzymes secretion. It has also been demonstrated recently that EDPs containing the GXXPG motif could induce pro-MMP1 and pro-MMP3 upregulation. Elastolysis could then cause collagen degradation and play an important role in the aging process. Many experimental studies have been devoted to EDPs, but their structure/activity relationships are not well elucidated yet. However, the assumption that their active conformation is a type VIII beta-turn on GXXP was highly suggested on the basis of predictive statistical calculations. Investigation of the EDPs three-dimensional (3D) structure would provide useful information for drug-design strategies to propose specific inhibitors. The work presented here reports theoretical results obtained from molecular dynamics simulations performed over 128 human EDPs containing the GXXP motif. We show that all the peptides, for which the central residues are not glycines, adopt a canonical (or very close to) type VIII beta-turn structure on the GXXP sequence. Amino acids surrounding this motif are also important for the structural behavior. Any residue located before the GXXP motif (XGXXP) increases the beta-turn stabilization, whereas the residue located after GXXP (GXXPX) has no significant structural effect. Moreover, we show their biological activity can be correlated with their ability to exhibit a type VIII beta-turn conformation.
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Affiliation(s)
- Gautier Moroy
- Laboratoire de Spectroscopies et Structures BioMoléculaires (LSSBM), IFR 53 Biomolécules, UFR Sciences Exactes et Naturelles, Université de Reims Champagne-Ardenne, BP 1039, 51687 Reims Cedex 2, France
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37
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Abstract
Elastin is a key extracellular matrix protein that is critical to the elasticity and resilience of many vertebrate tissues including large arteries, lung, ligament, tendon, skin, and elastic cartilage. Tropoelastin associates with multiple tropoelastin molecules during the major phase of elastogenesis through coacervation, where this process is directed by the precise patterning of mostly alternating hydrophobic and hydrophilic sequences that dictate intermolecular alignment. Massively crosslinked arrays of tropoelastin (typically in association with microfibrils) contribute to tissue structural integrity and biomechanics through persistent flexibility, allowing for repeated stretch and relaxation cycles that critically depend on hydrated environments. Elastin sequences interact with multiple proteins found in or colocalized with microfibrils, and bind to elastogenic cell surface receptors. Knowledge of the major stages in elastin assembly has facilitated the construction of in vitro models of elastogenesis, leading to the identification of precise molecular regions that are critical to elastin-based protein interactions.
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Affiliation(s)
- Suzanne M Mithieux
- School of Molecular and Microbial Biosciences, University of Sydney, New South Wales 2006, Australia
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38
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Abstract
The fact that elastin peptides, the degradation products of the extracellular matrix protein elastin, are chemotactic for numerous cell types, promote cell cycle progression and induce release of proteolytic enzymes by stromal and cancer cells, strongly suggests that their presence in tissues could contribute to tumour progression. Thus, elastin peptides qualify as matrikines, i.e. peptides originating from the fragmentation of matrix proteins and presenting biological activities. After a brief description of their origin, the biological activities of these peptides are reviewed, emphasising their potential role in cancer. The nature of their receptor and the signalling events it controls are also discussed. Finally, the structural selectivity of the elastin complex receptor is presented, leading to the concept of elastokine (matrikine originating from elastin fragmentation) and morpho-elastokine, i.e. peptides presenting a conformation similar to that of bioactive elastin peptides and mimicking their effects.
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Affiliation(s)
- Laurent Duca
- Université de Reims Champagne Ardenne, IFR53 Biomolécules, UFR Sciences Exactes et Naturelles, FRE CNRS 2534, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France
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39
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Piontkivska H, Zhang Y, Green ED, Elnitski L. Multi-species sequence comparison reveals dynamic evolution of the elastin gene that has involved purifying selection and lineage-specific insertions/deletions. BMC Genomics 2004; 5:31. [PMID: 15149554 PMCID: PMC436053 DOI: 10.1186/1471-2164-5-31] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Accepted: 05/18/2004] [Indexed: 12/14/2022] Open
Abstract
Background The elastin gene (ELN) is implicated as a factor in both supravalvular aortic stenosis (SVAS) and Williams Beuren Syndrome (WBS), two diseases involving pronounced complications in mental or physical development. Although the complete spectrum of functional roles of the processed gene product remains to be established, these roles are inferred to be analogous in human and mouse. This view is supported by genomic sequence comparison, in which there are no large-scale differences in the ~1.8 Mb sequence block encompassing the common region deleted in WBS, with the exception of an overall reversed physical orientation between human and mouse. Results Conserved synteny around ELN does not translate to a high level of conservation in the gene itself. In fact, ELN orthologs in mammals show more sequence divergence than expected for a gene with a critical role in development. The pattern of divergence is non-conventional due to an unusually high ratio of gaps to substitutions. Specifically, multi-sequence alignments of eight mammalian sequences reveal numerous non-aligning regions caused by species-specific insertions and deletions, in spite of the fact that the vast majority of aligning sites appear to be conserved and undergoing purifying selection. Conclusions The pattern of lineage-specific, in-frame insertions/deletions in the coding exons of ELN orthologous genes is unusual and has led to unique features of the gene in each lineage. These differences may indicate that the gene has a slightly different functional mechanism in mammalian lineages, or that the corresponding regions are functionally inert. Identified regions that undergo purifying selection reflect a functional importance associated with evolutionary pressure to retain those features.
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Affiliation(s)
- Helen Piontkivska
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Yi Zhang
- Department of Computer Science and Engineering, Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, PA 16802, USA
| | - Eric D Green
- Genome Technology Branch and NIH Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - NISC Comparative Sequencing Program
- Genome Technology Branch and NIH Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Laura Elnitski
- Department of Computer Science and Engineering, Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, PA 16802, USA
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40
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Urbán Z, Riazi S, Seidl TL, Katahira J, Smoot LB, Chitayat D, Boyd CD, Hinek A. Connection between elastin haploinsufficiency and increased cell proliferation in patients with supravalvular aortic stenosis and Williams-Beuren syndrome. Am J Hum Genet 2002; 71:30-44. [PMID: 12016585 PMCID: PMC384991 DOI: 10.1086/341035] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2002] [Accepted: 04/01/2002] [Indexed: 02/02/2023] Open
Abstract
To elucidate the pathomechanism leading to obstructive vascular disease in patients with elastin deficiency, we compared both elastogenesis and proliferation rate of cultured aortic smooth-muscle cells (SMCs) and skin fibroblasts from five healthy control subjects, four patients with isolated supravalvular aortic stenosis (SVAS), and five patients with Williams-Beuren syndrome (WBS). Mutations were determined in each patient with SVAS and in each patient with WBS. Three mutations found in patients with SVAS were shown to result in null alleles. RNA blot hybridization, immunostaining, and metabolic labeling experiments demonstrated that SVAS cells and WBS cells have reduced elastin mRNA levels and that they consequently deposit low amounts of insoluble elastin. Although SVAS cells laid down approximately 50% of the elastin made by normal cells, WBS cells deposited only 15% of the elastin made by normal cells. The observed difference in elastin-gene expression was not caused by a difference in the stability of elastin mRNA in SVAS cells compared with WBS cells, but it did indicate that gene-interaction effects may contribute to the complex phenotype observed in patients with WBS. Abnormally low levels of elastin deposition in SVAS cells and in WBS cells were found to coincide with an increase in proliferation rate, which could be reversed by addition of exogenous insoluble elastin. We conclude that insoluble elastin is an important regulator of cellular proliferation. Thus, the reduced net deposition of insoluble elastin in arterial walls of patients with either SVAS or WBS leads to the increased proliferation of arterial SMCs. This results in the formation of multilayer thickening of the tunica media of large arteries and, consequently, in the development of hyperplastic intimal lesions leading to segmental arterial occlusion.
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MESH Headings
- Adolescent
- Adult
- Aortic Stenosis, Supravalvular/genetics
- Aortic Stenosis, Supravalvular/metabolism
- Aortic Stenosis, Supravalvular/pathology
- Base Sequence
- Case-Control Studies
- Cell Division/genetics
- Cell Division/physiology
- Cells, Cultured
- Child
- Child, Preschool
- DNA Mutational Analysis
- DNA, Complementary/genetics
- Elastin/deficiency
- Elastin/genetics
- Elastin/metabolism
- Female
- Fibroblasts/metabolism
- Fibroblasts/pathology
- Humans
- Infant
- Male
- Middle Aged
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Solubility
- Williams Syndrome/genetics
- Williams Syndrome/metabolism
- Williams Syndrome/pathology
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Affiliation(s)
- Zsolt Urbán
- Pacific Biomedical Research Center, University of Hawaii, Honolulu; Divisions of Cardiovascular Research and Clinical Genetics, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto; and Children’s Hospital, Boston
| | - Sheila Riazi
- Pacific Biomedical Research Center, University of Hawaii, Honolulu; Divisions of Cardiovascular Research and Clinical Genetics, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto; and Children’s Hospital, Boston
| | - Thomas L. Seidl
- Pacific Biomedical Research Center, University of Hawaii, Honolulu; Divisions of Cardiovascular Research and Clinical Genetics, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto; and Children’s Hospital, Boston
| | - Jodi Katahira
- Pacific Biomedical Research Center, University of Hawaii, Honolulu; Divisions of Cardiovascular Research and Clinical Genetics, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto; and Children’s Hospital, Boston
| | - Leslie B. Smoot
- Pacific Biomedical Research Center, University of Hawaii, Honolulu; Divisions of Cardiovascular Research and Clinical Genetics, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto; and Children’s Hospital, Boston
| | - David Chitayat
- Pacific Biomedical Research Center, University of Hawaii, Honolulu; Divisions of Cardiovascular Research and Clinical Genetics, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto; and Children’s Hospital, Boston
| | - Charles D. Boyd
- Pacific Biomedical Research Center, University of Hawaii, Honolulu; Divisions of Cardiovascular Research and Clinical Genetics, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto; and Children’s Hospital, Boston
| | - Aleksander Hinek
- Pacific Biomedical Research Center, University of Hawaii, Honolulu; Divisions of Cardiovascular Research and Clinical Genetics, The Hospital for Sick Children, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto; and Children’s Hospital, Boston
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41
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Abstract
Three clinical conditions displaying phenotypic overlap have been linked to mutation or deletion of the elastin gene at 7q11.23. Supravalvar aortic stenosis, an autosomal dominant disorder characterized by elastin arteriopathy, is caused by mutation or intragenic deletions of ELN resulting in loss of function. Autosomal dominant cutis laxa, a primarily cutaneous condition, is the result of frameshift mutations at ELN that cause a dominant-negative effect on elastic fiber structure. Williams syndrome, a neurodevelopmental disorder is due to a 1.5 Mb deletion that includes ELN and at least 15 contiguous genes. The disorder is characterized by dysmorphic facies, mental retardation or learning difficulties, elastin arteriopathy, a unique cognitive profile of relative strength in auditory rote memory and language and extreme weakness in visuospatial constructive cognition, and a typical personality that includes overfriendliness, anxiety, and attention problems. The understanding of these disorders has progressed from phenotypic description to identification of causative mutations and insight into pathogenetic mechanisms for some aspects of the phenotype.
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Affiliation(s)
- C A Morris
- Department of Pediatrics, Division of Genetics, University of Nevada School of Medicine, Las Vegas, NV 89102, USA.
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42
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Carreras I, Rich CB, Jaworski JA, Dicamillo SJ, Panchenko MP, Goldstein R, Foster JA. Functional components of basic fibroblast growth factor signaling that inhibit lung elastin gene expression. Am J Physiol Lung Cell Mol Physiol 2001; 281:L766-75. [PMID: 11557580 DOI: 10.1152/ajplung.2001.281.4.l766] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previously, we have demonstrated that basic fibroblast growth factor (bFGF) decreases elastin gene transcription in confluent rat lung fibroblasts via the binding of a Fra-1-c-Jun heterodimer to an activator protein-1-cAMP response element in the distal region of the elastin promoter. In the present study, we show that bFGF activates the mitogen-activated protein kinase extracellular signal-regulated kinase 1/2, resulting in the translocation of phosphorylated extracellular signal-regulated kinase 1/2 into the nucleus followed by increased binding of Elk-1 to the serum response element of the c-Fos promoter, transient induction of c-Fos mRNA, and sustained induction of Fra-1 mRNA. The addition of PD-98059, an inhibitor of mitogen-activated protein kinase kinase, abrogates the bFGF-dependent repression of elastin mRNA expression. Comparative analyses of confluent and subconfluent fibroblast cultures reveal significant differences in elastin mRNA levels and activator protein-1 protein factors involved in the regulation of elastin transcription. These findings suggest that bFGF modulates specific cellular events that are dependent on the state of the cell and provide a rationale for the differential responses that can be expected in development and injury or repair situations.
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43
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Bashir MM, Abrams WR, Tucker T, Sellinger B, Budarf M, Emanuel B, Rosenbloom J. Molecular cloning and characterization of the bovine and human tuftelin genes. Connect Tissue Res 2001; 39:13-24; discussion 63-7. [PMID: 11062985 DOI: 10.3109/03008209809023908] [Citation(s) in RCA: 7] [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: 02/03/2023]
Abstract
The bovine tuftelin gene was cloned and its structure determined by DNA sequence analysis and comparison to bovine tuftelin cDNA. The analyses demonstrated that the cDNA contains a 1014 bp open reading frame encoding a protein of 338 residues with a calculated molecular weight of 38,630 kDa and an isoelectric point of 5.85. Although similar, these results differ from those previously published [Deutsch et al. (1991) J. Biol. Chem. 266, 16021-16028] which contained a different conceptual amino acid sequence for the carboxy terminal region and identification of a different termination codon because of the absence of a single guanine residue in the published sequence. The protein does not appear to share homology or domain motifs with any other known protein. The bovine gene consists of 13 exons ranging in size from 66 to 1531 bp, the latter containing the encoded carboxy terminal and 3' untranslated regions. These exons are embedded in greater than 28 kbp of genomic DNA and codons are generally not divided at exon/intron borders. Sequence analysis of the cDNA and products produced by reverse transcriptase/polymerase chain reaction demonstrated that exons 2, 5 and 6 are alternatively spliced. The 3' portion of the human gene was also isolated and characterized by DNA sequencing, which demonstrated agreement between the bovine and human sequences in the segment in question. The difference between the presently reported sequence and that of the previously published one suggests the possibility of an unusual type of polymorphism which would result in markedly different amino acid sequences at the carboxy terminal region of the protein. The human tuftelin gene was localized to chromosome 1q21 by in situ hybridization.
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Affiliation(s)
- M M Bashir
- Research Center in Oral Biology and Department of Anatomy and Histology, University of Pennsylvania School of Dental Medicine, Philadelphia 19104, USA
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44
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Robson P, Wright GM, Youson JH, Keeley FW. The structure and organization of lamprin genes: multiple-copy genes with alternative splicing and convergent evolution with insect structural proteins. Mol Biol Evol 2000; 17:1739-52. [PMID: 11070061 DOI: 10.1093/oxfordjournals.molbev.a026272] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Lamprin is a unique structural protein which forms the extracellular matrix of several cartilaginous structures found in the lamprey. Lamprin is noncollagenous in nature but shows sequence similarities to elastins and to insect structural proteins. Here, we characterize the structure and organization of lamprin genes, demonstrating the presence of multiple similar but not identical copies of the lamprin gene in the genome of the lamprey. In at least one species of lamprey, Lampetra richardsoni, the multiple gene copies are arranged in tandem in the genome in a head-to-tail orientation. Lamprin genes from Petromyzon marinus contain either seven or eight exons, with exon 4 being alternatively spliced in all genes, resulting in a total of six different lamprin transcripts. All exon junctions are of class 1,1. An unusual feature of the lamprin gene structure is the distribution of the 3' untranslated region sequence among multiple exons. A TATA box and cap sequence have been identified in upstream sequences in close proximity to the transcription start site, but no CAAT box could be identified. Sequence and gene structure comparisons between lamprins, elastins, and insect structural proteins suggest that the regions of sequence similarity are the result of a process of convergent evolution.
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Affiliation(s)
- P Robson
- Division of Cardiovascular Research, Hospital for Sick Children and Department of Biochemistry, University of Toronto, Toronto, Canada
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45
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Bisaccia F, Castiglione-Morelli MA, Spisani S, Serafini-Fracassini A, Tamburro AM. Solution structure of the amino acid sequence coded by the rarely expressed exon 26A of human elastin: the N-terminal region. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2000; 56:201-9. [PMID: 11083059 DOI: 10.1034/j.1399-3011.2000.00720.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We previously reported the structural and biological properties of the C-terminal sequence (REGDPSSSQHLPSTPSSPRV) coded by the rarely expressed exon 26A of human elastin. It assumes a stable type II beta-turn structure spanning the REGD sequence and possesses chemotactic and immunological properties. Here the structural characterization of the sequence coded by this exon was completed. Nuclear magnetic resonance and circular dichroism studies on the N-terminal amino acid sequence (GADEGVRRSLSPELREGD) showed the presence of an alpha-helix within VRRSL and a type II beta-turn within SPEL. The smaller peptides GADEGVRRSLSP and LSPELREGD revealed structural features similar to those identified in the parent peptide. No beta-turn was found in the REGD sequence of these peptides and no chemotactic activity was detected, thereby demonstrating that this biological activity is conformation dependent. Structural studies on additional peptides such as LREGD, ELREGD and LSPELREGDPSS showed that the presence of a Glu residue two positions before the Arg residue inhibits the beta-turn formation in the REGD sequence.
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Affiliation(s)
- F Bisaccia
- Department of Chemistry, University of Basilicata, Potenza, Italy
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46
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Colombatti A, Doliana R, Bot S, Canton A, Mongiat M, Mungiguerra G, Paron-Cilli S, Spessotto P. The EMILIN protein family. Matrix Biol 2000; 19:289-301. [PMID: 10963989 DOI: 10.1016/s0945-053x(00)00074-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The EMILINs are a new family of glycoproteins of the extracellular matrix. The prototype of this family is the chicken EMILIN that was originally identified in extracts of aortas; it was then found to be widely distributed in several tissues associated with elastin and localized at the interface between amorphous elastin and microfibrils. Based on peptide sequences, chicken and human cDNAs coding for EMILIN were isolated by RT/PCR by screening kidney and heart cDNA libraries. By using a C-terminal fragment of human EMILIN-1 as a bait in the yeast two-hybrid system, a second family member, EMILIN-2, has also been isolated. EMILINs are characterized by a C-terminal gC1q globular domain, a short collagenous sequence, a long coiled-coil region and a new cysteine-rich N-terminal domain that can be considered a hallmark of the family being present also in multimerin. The gene for EMILIN-1 was mapped on chromosome 2p23 overlapping with the promoter region of the ketohexokinase gene. The gC1q domain of EMILIN-1 can form relatively stable and compact homotrimers and this association is then followed by a multimeric assembly of disulfide-bonded protomers. Recombinant EMILIN-1 purified from the supernatant of 293 cells represents a very efficient ligand for cell adhesion of several cell types.
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Affiliation(s)
- A Colombatti
- Divisione di Oncologia Sperimentale 2, CRO-IRCCS, 33081, Aviano,
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47
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Perrin S, Rich CB, Morris SM, Stone PJ, Foster JA. The zebrafish swimbladder: A simple model for lung elastin injury and repair. Connect Tissue Res 2000; 40:105-12. [PMID: 10761635 DOI: 10.3109/03008209909029106] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In this communication we offer data to suggest that the zebrafish swimbladder may provide a simple model of elastin injury and repair which is amenable to genetic analysis and pertinent to lung physiology. In situ hybridization of zebrafish embryos illustrated that elastin gene expression is evident in the developing gut tract prior to swimbladder morphogenesis. Northern blot analysis demonstrated that the major zebrafish elastin mRNA is 2.0 kb which is significantly smaller than its higher vertebrate counterpart. Amino acid analysis of alkali-resistant protein from the anterior chamber of the adult zebrafish swimbladder showed a composition similar to higher vertebrate elastins including significant amounts of desmosine crosslinks. Electron microscopic investigations of the swimbladder wall indicate a simple structure with an inner layer of elastin fibers. Elastase delivery to the swimbladder in vitro resulted in significant fragmentation of elastin in the anterior chamber providing an environment for studying elastin repair within the tissue.
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Affiliation(s)
- S Perrin
- Department of Biochemistry, Boston University School of Medicine, MA 02118, USA
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48
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Lakkakorpi J, Li K, Decker S, Korkeela E, Piddington R, Abrams W, Bashir M, Uitto J, Rosenbloom J. Expression of the elastin promoter in novel tissue sites in transgenic mouse embryos. Connect Tissue Res 2000; 40:155-62. [PMID: 10761640 DOI: 10.3109/03008209909029111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have previously shown in a transgenic mouse line, in which 5.2 kb of the elastin promoter was linked to the reporter enzyme chloramphenicol acetyltransferase (CAT), that the highest levels of expression were found in embryonic lungs and aorta, while lower levels were detected in other elastin-containing tissues. Furthermore, in general, expression of the transgene showed developmental regulation similar to that of the endogenous gene. However, the precise location of cellular expression could not be determined in this model. To overcome this limitation, we have developed a similar model, but replaced CAT with the reporter enzyme beta-galactosidase. Enzyme activity was readily detected in the transgenic mouse embryos in expected regions of tissue forming elastic fibers, including the dermis and elastic cartilage. Of considerable interest, however, was the novel finding of expression in specific areas of neuroepithelium of the brain and in the perichondrium surrounding areas destined to form hyaline cartilage in endochondral bone formation. These latter areas included all the bones of the limbs, the spine and rib cage. It appeared that these segments of elastin expression demarcated the border between the developing cartilage and the surrounding mesenchymal tissue. Elastin promoter expression was also found in developing somites, in the mesenchymal layer of the forming cornea of the eye, in the genital tubercle and in the epithelium destined to form the olfactory epithelium. These findings indicate that the elastin promoter is activated during embryonic development in a variety of tissues, suggesting that elastin gene expression may play a role in organizing cutaneous, skeletal and neural structures.
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Affiliation(s)
- J Lakkakorpi
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, PA 19104, USA
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49
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Doliana R, Canton A, Bucciotti F, Mongiat M, Bonaldo P, Colombatti A. Structure, chromosomal localization, and promoter analysis of the human elastin microfibril interfase located proteIN (EMILIN) gene. J Biol Chem 2000; 275:785-92. [PMID: 10625608 DOI: 10.1074/jbc.275.2.785] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Elastin microfibril interfase-located protein (EMILIN) is an extracellular matrix glycoprotein abundantly expressed in elastin-rich tissues such as the blood vessels, skin, heart, and lung. It occurs with elastic fibers at the interface between amorphous elastin and microfibrils. In vitro experiments suggested a role for EMILIN in the process of elastin deposition. This multimodular protein consists of 995 amino acids; the domain organization includes a C1q-like globular domain at the C terminus, a short collagenous stalk, a region containing two leucine zippers, and at least four heptad repeats with a high potential for forming coiled-coil alpha-helices and, at the N terminus, a cysteine-rich sequence characterized by a partial epidermal growth factor-like motif and homologous to a region of multimerin. Here we report the complete characterization of the human and murine EMILIN gene, their chromosomal assignment, and preliminary functional data of the human promoter. A cDNA probe corresponding to the C terminus of EMILIN was used to isolate two genomic clones from a human BAC library. Sequencing of several derived subclones allowed the characterization of the whole gene that was found to be about 8 kilobases in size and to contain 8 exons and 7 introns. The internal exons range in size from 17 base pairs to 1929 base pairs. All internal intron/exon junctions are defined by canonical splice donor and acceptor sites, and the different domains potentially involved in the formation of a coiled-coil structure are clustered in the largest exon. The 3'-end of the EMILIN gene overlaps with the 5'-end of the promoter region of the ketohexokinase gene, whose chromosomal position is between markers D2S305 and D2S165 on chromosome 2. A 1600-base pair-long sequence upstream of the translation starting point was evaluated for its promoter activity; five deletion constructs were assayed after transfection in primary chicken fibroblasts and in a human rhabdomyosarcoma cell line. This analysis indicates the existence of two contiguous regions able to modulate luciferase expression in both cell types used, one with a strong activatory function, ranging from positions -204 to -503, and the other, ranging from positions -504 to -683, with a strong inhibitory function.
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Affiliation(s)
- R Doliana
- Divisione di Oncologia Sperimentale 2, Centro di Riferimento Oncologico, 33081 Aviano, Italy
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50
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Berk JL, Massoomi N, Hatch C, Goldstein RH. Hypoxia downregulates tropoelastin gene expression in rat lung fibroblasts by pretranslational mechanisms. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:L566-72. [PMID: 10484464 DOI: 10.1152/ajplung.1999.277.3.l566] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Elastolytic lung injury disrupts cell barriers, flooding alveoli and producing regional hypoxia. Abnormal O2 tensions may alter repair of damaged elastin fibers. To determine the effect of hypoxia on extravascular elastin formation, we isolated rat lung fibroblasts and cultured them under a variety of O2 conditions. Hypoxia downregulated tropoelastin mRNA in a dose- and time-related fashion while upregulating glyceraldehyde-3-phosphate dehydrogenase mRNA levels. The changes in tropoelastin gene expression were not due to cell toxicity as measured by chromium release and cell proliferation studies. Neither cycloheximide nor actinomycin D abrogated this effect. Hypoxia induced early decreases in tropoelastin mRNA stability; minor suppression of gene transcription occurred later. When returned to 21% O2, tropoelastin mRNA recovered to control levels in part by upregulating tropoelastin gene transcription. Taken together, these data indicate that hypoxia regulates tropoelastin gene expression and may alter repair of acutely injured lung.
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Affiliation(s)
- J L Berk
- Pulmonary Center, Boston University School of Medicine and Boston Veterans Affairs Medical Center, Boston, Massachusetts 02118, USA.
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