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Peterson RJ, Koval M. Above the Matrix: Functional Roles for Apically Localized Integrins. Front Cell Dev Biol 2021; 9:699407. [PMID: 34485286 PMCID: PMC8414885 DOI: 10.3389/fcell.2021.699407] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 07/23/2021] [Indexed: 12/14/2022] Open
Abstract
Integrins are transmembrane proteins that are most typically thought of as integrating adhesion to the extracellular matrix with intracellular signaling and cell regulation. Traditionally, integrins are found at basolateral and lateral cell surfaces where they facilitate binding to the ECM and intercellular adhesion through cytosolic binding partners that regulate organization of actin microfilaments. However, evidence is accumulating that integrins also are apically localized, either endogenously or due to an exogenous stimulus. Apically localized integrins have been shown to regulate several processes by interacting with proteins such as connexins, tight junction proteins, and polarity complex proteins. Integrins can also act as receptors to mediate endocytosis. Here we review these newly appreciated roles for integrins localized to the apical cell surface.
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Affiliation(s)
- Raven J Peterson
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States.,Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
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2
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De Rose AF, Mantica G, Bocca B, Szpytko A, Van der Merwe A, Terrone C. Supporting the role of penile trauma and micro-trauma in the etiology of Peyronie's disease. Prospective observational study using the electronic microscope to examine two types of plaques. Aging Male 2020; 23:740-745. [PMID: 30879382 DOI: 10.1080/13685538.2019.1586870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES The etiopathogenesis of Peyronie's disease (PD) remains not clearly understood. The most accepted theory attributes the histological lesions of PD to the effects of trauma to the corpora cavernosum of the penis. The aim of our study is to verify whether similar histological features exist between these two tissues, providing new evidence in favor of the traumatic theory in the etiopathogenesis of Peyronie's disease. MATERIALS AND METHODS A prospective observational study was carried out at our institution from January 2013 to June 2018, involving patients having undergone surgery for PD and those with delayed surgery for penile trauma. Both excised PD and post-traumatic plaques were analyzed by blind pathologists with an 80kV potential acceleration electron microscope. RESULTS Five patients were identified with a post-traumatic plaque (Group 1) and therefore an equal number of PD patients were enrolled for Group 2. The ultrastructural characteristics of the two types of preparations were very similar. In all the samples we showed an inflammatory reaction of the structure of the tunica albuginea, a production of the disorganized extracellular matrix, a proliferation of inflammatory cells and fibroblasts. Furthermore, we have found an increase in the density and collagen deposits grouped in the extracellular space and within the fibroblasts. CONCLUSIONS These findings support the theory that attributes lesions and symptoms typical of PD to the effects of cavernous body trauma.
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Affiliation(s)
- Aldo Franco De Rose
- Department of Urology, Policlinico San Martino Hospital, University of Genova, Genova, Italy
| | - Guglielmo Mantica
- Department of Urology, Policlinico San Martino Hospital, University of Genova, Genova, Italy
- Department of Urology, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa
| | - Bruna Bocca
- Department of Pathology, Policlinico San Martino Hospital, University of Genova, Genova, Italy
| | - Alexander Szpytko
- Department of Urology, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa
| | - André Van der Merwe
- Department of Urology, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa
| | - Carlo Terrone
- Department of Urology, Policlinico San Martino Hospital, University of Genova, Genova, Italy
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3
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Feaver RE, Gelfand BD, Wang C, Schwartz MA, Blackman BR. Atheroprone hemodynamics regulate fibronectin deposition to create positive feedback that sustains endothelial inflammation. Circ Res 2010; 106:1703-11. [PMID: 20378855 DOI: 10.1161/circresaha.109.216283] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
RATIONALE The extracellular matrix protein fibronectin (FN) is focally deposited in regions of atherosclerosis, where it contributes to inflammatory signaling. OBJECTIVE To elucidate the mechanism by which FN deposition is regulated by local shear stress patterns, its dependence on platelet-endothelial cell adhesion molecule (PECAM)-1 mechanotransduction and the role this pathway plays in sustaining an atheroprone/proinflammatory phenotype. METHODS AND RESULTS Human endothelial cells were exposed in vitro to atheroprone or atheroprotective shear stress patterns derived from human carotid arteries. Onset of atheroprotective flow induced a transient increase in FN deposition, whereas atheroprone flow caused a steady increase in FN expression and integrin activation over time, leading to a significant and sustained increase in FN deposition relative to atheroprotective conditions. Comparing FN staining in ApoE(-/-) and ApoE(-/-)PECAM(-/-) mice showed that PECAM-1 was essential for FN accumulation in atheroprone regions of the aortic arch. In vitro, small interfering RNA against PECAM-1 blocked the induction of FN and the activation of nuclear factor (NF)-kappaB by atheroprone flow, which was rescued by the addition of exogenous FN. Additionally, blocking NF-kappaB activation attenuated the flow-induced FN expression. Small interfering RNA against FN significantly reduced NF-kappaB activity, which was rescued by the addition of exogenous FN. CONCLUSIONS These results indicate that FN gene expression and assembly into matrix fibrils is induced by atheroprone fluid shear stress. This effect is mediated at least in part by the transcription factor NF-kappaB. Additionally, because FN promotes activation of NF-kappaB, atheroprone shear stress creates a positive feedback to maintain inflammation.
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Affiliation(s)
- Ryan E Feaver
- Associate Professor, Department of Biomedical Engineering, University of Virginia, Box 800759, Health System, Charlottesville, VA 22908, USA
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4
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White ES, Baralle FE, Muro AF. New insights into form and function of fibronectin splice variants. J Pathol 2008; 216:1-14. [PMID: 18680111 DOI: 10.1002/path.2388] [Citation(s) in RCA: 233] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The extracellular matrix (ECM) is a highly dynamic structure that not only provides a physical framework for cells within connective tissues, but also imparts instructive signals for development, tissue homeostasis and basic cell functions through its composition and ability to exert mechanical forces. The ECM of tissues is composed of, in addition to proteoglycans and hyaluronic acid, a number of proteins, most of which are generated after alternative splicing of their pre-mRNA. However, the precise function of these protein isoforms is still obscure in most cases. Fibronectin (FN), one of the main components of the ECM, is also one of the best-known examples of a family of proteins generated by alternative splicing, having at least 20 different isoforms in humans. Over the last few years, considerable progress on elucidating the functions of the alternatively spliced FN isoforms has been achieved with the essential development of key engineered mouse strains. Here we summarize the phenotypes of the mouse strains having targeted mutations in the FN gene, which may lead to novel insights linking function of alternatively spliced isoforms of fibronectin to human pathologies.
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Affiliation(s)
- E S White
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
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Locke JM, Harries LW. RNA processing and mRNA surveillance in monogenic diabetes. GENE REGULATION AND SYSTEMS BIOLOGY 2008; 2:203-12. [PMID: 19787084 PMCID: PMC2733086 DOI: 10.4137/grsb.s782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In the eukaryotic cell a number of molecular mechanisms exist to regulate the nature and quantity of transcripts intended for translation. For monogenic diabetes an understanding of these processes is aiding scientists and clinicians in studying and managing this disease. Knowledge of RNA processing and mRNA surveillance pathways is helping to explain disease mechanisms, form genotype-phenotype relationships, and identifying new regions within genes to screen for mutations. Furthermore, recent insights into the regulatory role of micro RNAs (miRNAs) and RNA editing in the pancreas suggests that these mechanisms may also be important in the progression to the diabetic state.
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Affiliation(s)
- Jonathan M Locke
- Institute of Biomedical and Clinical Sciences, Peninsula Medical School, Exeter, UK
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7
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Moretti FA, Chauhan AK, Iaconcig A, Porro F, Baralle FE, Muro AF. A Major Fraction of Fibronectin Present in the Extracellular Matrix of Tissues Is Plasma-derived. J Biol Chem 2007; 282:28057-62. [PMID: 17644525 DOI: 10.1074/jbc.m611315200] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The origin of the fibronectin (FN) found in the extracellular matrix of tissues has not been defined experimentally. Previous studies suggest that there is contribution from both local tissue production and transfer from plasma, but the extent of this phenomenon has not been addressed. We have shown before that engineered mice constitutively expressing extra domain A-containing FN (EDA(+)FN) have a significant decrease of FN levels in plasma and most tissues. We showed that hepatocytes modified to produce EDA(+)FN have normal extracellular matrix-FN levels but secrete less soluble FN. When we performed a liver-specific EDA-exon deletion in these animals, FN levels were restored both in plasma and tissues. Therefore, an important fraction of tissue FN, approximately an equal amount of that produced by the tissue itself, is actually plasma-derived, suggesting that plasma is an important source of tissue FN. The present results have potential significance for understanding the contributions of plasma FN, and perhaps other plasma proteins, in the modulation of cellular activities and in the formation of the extracellular matrix of tissues.
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Affiliation(s)
- Federico A Moretti
- International Centre for Genetic Engineering and Biotechnology, 34012 Trieste, Italy
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8
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Han F, Gilbert JR, Harrison G, Adams CS, Freeman T, Tao Z, Zaka R, Liang H, Williams C, Tuan RS, Norton PA, Hickok NJ. Transforming growth factor-beta1 regulates fibronectin isoform expression and splicing factor SRp40 expression during ATDC5 chondrogenic maturation. Exp Cell Res 2007; 313:1518-32. [PMID: 17391668 PMCID: PMC1920702 DOI: 10.1016/j.yexcr.2007.01.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2005] [Revised: 01/09/2007] [Accepted: 01/17/2007] [Indexed: 11/28/2022]
Abstract
Fibronectin (FN) isoform expression is altered during chondrocyte commitment and maturation, with cartilage favoring expression of FN isoforms that includes the type II repeat extra domain B (EDB) but excludes extra domain A (EDA). We and others have hypothesized that the regulated splicing of FN mRNAs is necessary for the progression of chondrogenesis. To test this, we treated the pre-chondrogenic cell line ATDC5 with transforming growth factor-beta1, which has been shown to modulate expression of the EDA and EDB exons, as well as the late markers of chondrocyte maturation; it also slightly accelerates the early acquisition of a sulfated proteoglycan matrix without affecting cell proliferation. When chondrocytes are treated with TGF-beta1, the EDA exon is preferentially excluded at all times whereas the EDB exon is relatively depleted at early times. This regulated alternative splicing of FN correlates with the regulation of alternative splicing of SRp40, a splicing factor facilitating inclusion of the EDA exon. To determine if overexpression of the SRp40 isoforms altered FN and FN EDA organization, cDNAs encoding these isoforms were overexpressed in ATDC5 cells. Overexpression of the long-form of SRp40 yielded an FN organization similar to TGF-beta1 treatment; whereas overexpression of the short form of SRp40 (which facilitates EDA inclusion) increased formation of long-thick FN fibrils. Therefore, we conclude that the effects of TGF-beta1 on FN splicing during chondrogenesis may be largely dependent on its effect on SRp40 isoform expression.
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Affiliation(s)
- Fei Han
- Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - James R. Gilbert
- Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Gerald Harrison
- Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Christopher S. Adams
- Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Theresa Freeman
- Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Zhuliang Tao
- Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Raihana Zaka
- Division of Rheumatology, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Hongyan Liang
- Department of Biochemistry & Molecular Pharmacology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Charlene Williams
- Department of Biochemistry & Molecular Pharmacology, Thomas Jefferson University, Philadelphia, Pennsylvania
- Division of Rheumatology, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Rocky S. Tuan
- Cartilage Biology and Orthopaedics Branch, NIAMS, NIH, Bethesda, MD
| | - Pamela A. Norton
- Department of Biochemistry & Molecular Pharmacology, Thomas Jefferson University, Philadelphia, Pennsylvania
- Jefferson Center for Biomedical Research, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Noreen J. Hickok
- Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania
- ‡ To Whom Correspondence Should be Addressed: Noreen J. Hickok, Ph.D., Department of Orthopaedic Surgery, Thomas Jefferson University, 1015 Walnut St., Suite 501, Philadelphia, PA 19107, Tel: 215-955-6979, Fax: 215-955-4317, e-mail:
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Abe Y, Bui-Thanh NA, Ballantyne CM, Burns AR. Extra domain A and type III connecting segment of fibronectin in assembly and cleavage. Biochem Biophys Res Commun 2005; 338:1640-7. [PMID: 16277979 DOI: 10.1016/j.bbrc.2005.10.134] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Accepted: 10/20/2005] [Indexed: 10/25/2022]
Abstract
To determine the role of the extra domain A (EDA) and type III connecting segment (IIICS) of fibronectin in fiber assembly, topographical distribution and proteolytic cleavage, eight full-length human fibronectin cDNA variants (aa0, aa64, aa89, and aa120 variations in the IIICS with or without the EDA) tagged with the V5 epitope were cloned from human endothelial cells and were expressed in CHO-K1 cells. All eight variants were assembled on cell surfaces. However, only the EDA(+) variants, regardless of the type of the IIICS domain, formed extensive fibrous networks. In contrast, the EDA(-)/aa64 and EDA(-)/aa89 variants were present predominantly as a soluble form. Western analysis of both soluble and cell-associated fibronectin/V5 variants showed that aa64, aa89, and aa120 variants with or without the EDA domain produced the major 50- to 62-kDa C-terminal fragments, whereas the aa0 variants did not, suggesting that the IIICS domain provides proteolytic cleavage sites.
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Affiliation(s)
- Yasunori Abe
- Section of Atherosclerosis and Lipoprotein Research, Department of Medicine, Baylor College of Medicine, USA.
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10
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Stoss O, Novoyatleva T, Gencheva M, Olbrich M, Benderska N, Stamm S. p59(fyn)-mediated phosphorylation regulates the activity of the tissue-specific splicing factor rSLM-1. Mol Cell Neurosci 2005; 27:8-21. [PMID: 15345239 DOI: 10.1016/j.mcn.2004.04.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Revised: 04/22/2004] [Accepted: 04/29/2004] [Indexed: 02/08/2023] Open
Abstract
The Sam68-like mammalian protein SLM-1 is a member of the STAR protein family and is related to SAM68 and SLM-2. Here, we demonstrate that rSLM-1 interacts with itself, scaffold-attachment factor B, YT521-B, SAM68, rSLM-2, SRp30c, and hnRNP G. rSLM-1 regulates splice site selection in vivo via a purine-rich enhancer. In contrast to the widely expressed SAM68 and rSLM-2 proteins, rSLM-1 is found primarily in brain and, to a much smaller degree, in testis. In the brain, rSLM-1 and rSLM-2 are predominantly expressed in different neurons. In the hippocampal formation, rSLM-1 is present only in the dentate gyrus, whereas rSLM-2 is found in the pyramidal cells of the CA1, CA3, and CA4 regions. rSLM-1, but not rSLM-2, is phosphorylated by p59(fyn). p59(fyn)-mediated phosphorylation abolishes the ability of rSLM-1 to regulate splice site selection, but has no effect on rSLM-2 activity. This suggests that rSLM-1-positive cells could respond with a change of their splicing pattern to p59(fyn) activation, whereas rSLM-2-positive cells would not be affected. Together, our data indicate that rSLM-1 is a tissue-specific splicing factor whose activity is regulated by tyrosine phosphorylation signals emanating from p59(fyn).
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Affiliation(s)
- Oliver Stoss
- Klinikum Kassel, Pathology, Mönchebergstr. 41-43, D-34125 Kassel, Germany
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11
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Han F, Adams CS, Tao Z, Williams CJ, Zaka R, Tuan RS, Norton PA, Hickok NJ. Transforming growth factor-β1 (TGF-β1) regulates ATDC5 chondrogenic differentiation and fibronectin isoform expression. J Cell Biochem 2005; 95:750-62. [PMID: 15832361 DOI: 10.1002/jcb.20427] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Regulated splicing of fibronectin (FN) occurs during the mesenchymal to chondrocyte transition and ultimately results in the relative enrichment of an extra domain B (EDB) exon-containing FN isoform with the suggestion that FN isoforms may play a functional role in chondrogenesis. Promotion of chondrogenesis can also be achieved by treatment with transforming growth factor-beta (TGF-beta), which also regulates FN isoform expression. We have examined the effects of TGF-beta treatment on the assumption of the chondrogenic phenotype in the teratoma-derived cell line ATDC5 and tested whether these effects on chondrogenesis are paralleled by appropriate changes in FN isoform expression. ATDC5 cells were maintained in a pre-chondrogenic state and, in this state, treated with 10 ng/ml TGF-beta. The cells started to elaborate a matrix rich in sulfated proteoglycans, such that within the first 12 days of culture, TGF-beta1 treatment appeared to slightly accelerate early acquisition of an Alcian blue-stained matrix, and caused a dose- and time-dependent decrease in collagen type I expression; changes in collagen type II expression were variable. At later times, cells treated with TGF-beta became indistinguishable from those of the controls. Interestingly, TGF-beta treatment caused a significant dose- and time-dependent decrease in the proportion of FN containing the extra domain A (EDA) and the EDB exons. These data suggest that TGF-beta induces the early stages of chondrogenic maturation in this pre-chondrogenic line and that TGF-beta treatment increases expression of FN isoforms that lack the EDA and EDB exons.
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Affiliation(s)
- Fei Han
- Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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12
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Cunningham O, Andolfo A, Santovito ML, Iuzzolino L, Blasi F, Sidenius N. Dimerization controls the lipid raft partitioning of uPAR/CD87 and regulates its biological functions. EMBO J 2004; 22:5994-6003. [PMID: 14609946 PMCID: PMC275445 DOI: 10.1093/emboj/cdg588] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The urokinase-type plasminogen activator receptor (uPAR/CD87) is a glycosylphosphatidylinositol-anchored membrane protein with multiple functions in extracellular proteolysis, cell adhesion, cell migration and proliferation. We now report that cell surface uPAR dimerizes and that dimeric uPAR partitions preferentially to detergent-resistant lipid rafts. Dimerization of uPAR did not require raft partitioning as the lowering of membrane cholesterol failed to reduce dimerization and as a transmembrane uPAR chimera, which does not partition to lipid rafts, also dimerized efficiently. While uPA bound to uPAR independently of its membrane localization and dimerization status, uPA-induced uPAR cleavage was strongly accelerated in lipid rafts. In contrast to uPA, the binding of Vn occurred preferentially to raft- associated dimeric uPAR and was completely blocked by cholesterol depletion.
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Affiliation(s)
- Orla Cunningham
- Molecular Genetics Unit, Department of Molecular Biology and Functional Genomics, Università Vita-Salute San Raffaele, Via Olgettina 58, 20132 Milan, Italy
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Abstract
Alternative pre-mRNA splicing is a central mode of genetic regulation in higher eukaryotes. Variability in splicing patterns is a major source of protein diversity from the genome. In this review, I describe what is currently known of the molecular mechanisms that control changes in splice site choice. I start with the best-characterized systems from the Drosophila sex determination pathway, and then describe the regulators of other systems about whose mechanisms there is some data. How these regulators are combined into complex systems of tissue-specific splicing is discussed. In conclusion, very recent studies are presented that point to new directions for understanding alternative splicing and its mechanisms.
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Affiliation(s)
- Douglas L Black
- Department of Microbiology, Immunology, and Molecular Genetics, Howard Hughes Medical Institute, University of California-Los Angeles, Los Angeles, California 90095-1662, USA.
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14
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Frank J, Roux J, Kawakatsu H, Su G, Dagenais A, Berthiaume Y, Howard M, Canessa CM, Fang X, Sheppard D, Matthay MA, Pittet JF. Transforming growth factor-beta1 decreases expression of the epithelial sodium channel alphaENaC and alveolar epithelial vectorial sodium and fluid transport via an ERK1/2-dependent mechanism. J Biol Chem 2003; 278:43939-50. [PMID: 12930837 DOI: 10.1074/jbc.m304882200] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Acute lung injury (ALI) is characterized by the flooding of the alveolar airspaces with protein-rich edema fluid and diffuse alveolar damage. We have previously reported that transforming growth factor-beta1 (TGF-beta1) is a critical mediator of ALI after intratracheal administration of bleomycin or Escherichia coli endotoxin, at least in part due to effects on lung endothelial and alveolar epithelial permeability. In the present study, we hypothesized that TGF-beta1 would also decrease vectorial ion and water transport across the distal lung epithelium. Therefore, we studied the effect of active TGF-beta1 on 22Na+ uptake across monolayers of primary rat and human alveolar type II (ATII) cells. TGF-beta1 significantly reduced the amiloride-sensitive fraction of 22Na+ uptake and fluid transport across monolayers of both rat and human ATII cells. TGF-beta1 also significantly decreased alphaENaC mRNA and protein expression and inhibited expression of a luciferase reporter downstream of the alphaENaC promoter in lung epithelial cells. The inhibitory effect of TGF-beta1 on sodium uptake and alphaENaC expression in ATII cells was mediated by activation of the MAPK, ERK1/2. Consistent with the in vitro results, TGF-beta1 inhibited the amiloride-sensitive fraction of the distal airway epithelial fluid transport in an in vivo rat model at a dose that was not associated with any change in epithelial protein permeability. These data indicate that increased TGF-beta1 activity in the distal airspaces during ALI promotes alveolar edema by reducing distal airway epithelial sodium and fluid clearance. This reduction in sodium and fluid transport is attributable in large part to a reduction in apical membrane alphaENaC expression mediated through an ERK1/2-dependent inhibition of the alphaENaC promoter activity.
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Affiliation(s)
- James Frank
- Laboratory of Surgical Research, Cardiovascular Research Institute, Lung Biology Center, Departments of Anesthesia, Surgery, and Medicine, University of California, San Francisco, California 94110, USA
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15
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Muro AF, Chauhan AK, Gajovic S, Iaconcig A, Porro F, Stanta G, Baralle FE. Regulated splicing of the fibronectin EDA exon is essential for proper skin wound healing and normal lifespan. J Cell Biol 2003; 162:149-60. [PMID: 12847088 PMCID: PMC2172721 DOI: 10.1083/jcb.200212079] [Citation(s) in RCA: 232] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Fibronectins (FNs) are multifunctional high molecular weight glycoproteins present in the blood plasma and in the ECMs of tissues. The FN primary transcript undergoes alternative splicing in three regions generating up to 20 main different variants in humans. However, the precise role of the FN isoforms is poorly understood. One of the alternatively spliced exons is the extra domain A (EDA) or extra type III homology that is regulated spatially and temporally during development and aging. To study its in vivo function, we generated mice devoid of EDA exon-regulated splicing. Constitutive exon inclusion was obtained by optimizing the splice sites, whereas complete exclusion was obtained after in vivo CRE-loxP-mediated deletion of the exon. Homozygous mouse strains with complete exclusion or inclusion of the EDA exon were viable and developed normally, indicating that the alternative splicing at the EDA exon is not necessary during embryonic development. Conversely, mice without the EDA exon in the FN protein displayed abnormal skin wound healing, whereas mice having constitutive inclusion of the EDA exon showed a major decrease in the FN levels in all tissues. Moreover, both mutant mouse strains have a significantly shorter lifespan than the control mice, suggesting that EDA splicing regulation is necessary for efficient long-term maintenance of biological functions.
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Affiliation(s)
- Andrés F. Muro
- International Centre for Genetic Engineering and Biotechnology, 34012 Trieste, Italy
| | - Anil K. Chauhan
- International Centre for Genetic Engineering and Biotechnology, 34012 Trieste, Italy
| | - Srecko Gajovic
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Alessandra Iaconcig
- International Centre for Genetic Engineering and Biotechnology, 34012 Trieste, Italy
| | - Fabiola Porro
- International Centre for Genetic Engineering and Biotechnology, 34012 Trieste, Italy
| | - Giorgio Stanta
- International Centre for Genetic Engineering and Biotechnology, 34012 Trieste, Italy
- Department of Clinical, Morphological and Technological Sciences, University of Trieste, 34100 Trieste, Italy
| | - Francisco E. Baralle
- International Centre for Genetic Engineering and Biotechnology, 34012 Trieste, Italy
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16
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Black DL, Grabowski PJ. Alternative pre-mRNA splicing and neuronal function. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2003; 31:187-216. [PMID: 12494767 DOI: 10.1007/978-3-662-09728-1_7] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- D L Black
- Howard Hughes Medical Institute, University of California, Los Angeles, MRL 5-748, 675 Charles E. Young Dr. South, Los Angeles, California 90095, USA
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Costacurta A, Priante G, D'Angelo A, Chieco-Bianchi L, Cantaro S. Decorin transfection in human mesangial cells downregulates genes playing a role in the progression of fibrosis. J Clin Lab Anal 2002; 16:178-86. [PMID: 12112390 PMCID: PMC6807966 DOI: 10.1002/jcla.10038] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The proteoglycan decorin inhibits TGF-beta; therefore, it could antagonize progression of fibrotic diseases associated with activation of TGF-beta(1). The effect of decorin transfection in human mesangial cells (HMCs) on the expression of genes related to kidney fibrosis was investigated. HMCs, isolated from glomeruli of healthy portions of human kidneys removed due to carcinoma, were histochemically typed. Decorin cDNA cloned in a eukaryotic expression vector was transfected into HMCs. Gene expression of fibrogenetic cytokines and fibrotic proteins TGF-beta(1), PDGF-beta, alpha(1) collagen type IV, alpha(1) collagen type I, fibronectin, and tenascin was analyzed, by reverse transcription polymerase chain reaction (RT-PCR), 24 hr after transfection. Immunoblotting analysis of protein extracts using anti-decorin IgG, revealed a positive signal of about 52 MDa, corresponding to the molecular weight of decorin, in cultures transfected with the decorin gene. Decorin mRNA increased about 12 times in cultures transfected with the construct pCR3.1-Deco. Cells with increased decorin synthesis showed a 61% decrease of TGF-beta(1) mRNA, a 71% reduction of alpha1 collagen type IV mRNA, and a 29% reduction of fibronectin mRNA. This study is the first to investigate decorin transfection into human mesangial cells, and supports the use of the decorin gene to control the progression of glomerular and interstitial fibrosis in kidney diseases.
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Affiliation(s)
- Antonia Costacurta
- Department of Medical and Surgical Sciences, Nephrology, University of Padova, Padova, Italy.
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18
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Chew LJ, Pan H, Yu J, Tian S, Huang WQ, Zhang JY, Pang S, Li LY. A novel secreted splice variant of vascular endothelial cell growth inhibitor. FASEB J 2002; 16:742-4. [PMID: 11923219 DOI: 10.1096/fj.01-0757fje] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Vascular endothelial cell growth inhibitor (VEGI), a member of the tumor necrosis factor (TNF) family, is an endothelial cell-specific inhibitor of angiogenesis. Overexpression by cancer cells of a secretable VEGI fusion protein resulted in abrogation of xenograft tumor progression, but overexpression of full-length VEGI was completely without effect. This finding indicates that secretion is essential for VEGI action. Here we report the identification of two new VEGI isoforms consisting of 251 and 192 amino acid residues. Both isoforms show endothelial cell-specific expression and share a C-terminal 151-residue segment with the previously described VEGI, which comprises 174 residues. The isoforms are generated from a 17 kb human gene by alternative splicing. Their expression is regulated in parallel by inflammatory cytokines TNF-alpha and interferon-gamma. VEGI-251, the most abundant isoform, contains a putative secretion signal. VEGI protein is detected in conditioned media of endothelial cells and VEGI-251-transfected mammalian cells. Overexpression of VEGI-251 in endothelial cells causes dose-dependent cell death. VEGI-251-transfected cancer cells form xenograft tumors of reduced growth rate and microvessel density compared with tumors of empty vector transfectants. These findings support the view that endothelial cell-secreted VEGI may function as an autocrine inhibitor of angiogenesis and a naturally existing modulator of vascular homeostasis.
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Affiliation(s)
- Li-Jin Chew
- Department of Oncology, Lombardi Cancer Center, Georgetown University Medical Center, Washington, DC 20007, USA
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19
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Abstract
Tissue-specific alternative splicing profoundly effects animal physiology, development and disease, and this is nowhere more evident than in the nervous system. Alternative splicing is a versatile form of genetic control whereby a common pre-mRNA is processed into multiple mRNA isoforms differing in their precise combination of exon sequences. In the nervous system, thousands of alternatively spliced mRNAs are translated into their protein counterparts where specific isoforms play roles in learning and memory, neuronal cell recognition, neurotransmission, ion channel function, and receptor specificity. The essential nature of this process is underscored by the finding that its misregulation is a common characteristic of human disease. This review highlights the current views of the biological phenomenon of alternative splicing, and describes evidence for its intricate underlying biochemical mechanisms. The roles of RNA binding proteins and their tissue-specific properties are discussed. Why does alternative splicing occur in cosmic proportions in the nervous system? How does it affect integrated cellular functions? How are region-specific, cell-specific and developmental differences in splicing directed? How are the control mechanisms that operate in the nervous system distinct from those of other tissues? Although there are many unanswered questions, substantial progress has been made in showing that alternative splicing is of major importance in generating proteomic diversity, and in modulating protein activities in a temporal and spatial manner. The relevance of alternative splicing to diseases of the nervous system is also discussed.
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Affiliation(s)
- P J Grabowski
- Department of Biological Sciences, Howard Hughes Medical Institute, A507LH, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA.
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20
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Gratchev A, Guillot P, Hakiy N, Politz O, Orfanos CE, Schledzewski K, Goerdt S. Alternatively activated macrophages differentially express fibronectin and its splice variants and the extracellular matrix protein betaIG-H3. Scand J Immunol 2001; 53:386-92. [PMID: 11285119 DOI: 10.1046/j.1365-3083.2001.00885.x] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Alternative activation of macrophages, induced by Th2 cytokines and glucocorticoids, is essential for the proper functioning of anti-inflammatory immune reactions. To this end, alternatively activated macrophages (aaMPhi) express a not yet fully unravelled set of genes including cytokines such as alternative macrophage activation-associated CC-chemokine (AMAC)-1 and pattern recognition molecules such as the scavenger receptor CD163. In order to further characterize the molecular repertoire of aaMPhi, differential gene expression was analyzed by combining subtractive suppression cloning and differential hybridization. We show here that aaMPhi induced by interleukin (IL)-4 overexpress the prototype extracellular matrix (ECM) protein fibronectin on the mRNA and protein level. This overall increase is accompanied by a shift in fibronectin splice variants from an embryonic to a mature pattern. In addition, the expression of another ECM protein, betaIG-H3, is also upregulated by IL-4 in aaMPhi. In contrast to IL-4 and in line with its inhibitory effect on wound healing, dexamethasone exerts a strongly suppressive effect on fibronectin and betaIG-H3 expression. In conclusion, overexpression of ECM proteins induced by IL-4 in macrophages suggests that aaMPhi may be involved in ECM deposition and tissue remodelling during the healing phase of acute inflammatory reactions and in chronic inflammatory diseases.
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Affiliation(s)
- A Gratchev
- Klinik und Poliklinik für Dermatologie, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Berlin, Germany.
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21
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Abstract
Alternative RNA processing is a mechanism for creation of protein diversity through selective inclusion or exclusion of RNA sequence during posttranscriptional processing. More than one-third of human pre-mRNAs undergo alternative RNA processing modification, making this a ubiquitous biological process. The protein isoforms produced have distinct and sometimes opposite functions, underscoring the importance of this process. This review focuses on important endocrine genes regulated by alternative RNA processing. We discuss how diverse events such as spermatogenesis or GH action are regulated by this process. We focus on several endocrine (calcitonin/calcitonin gene-related peptide) and nonendocrine (Drosophila doublesex and P-element and mouse c-src) examples to highlight recent progress in the elucidation of molecular mechanisms regulating this process. Finally, we outline methods (model systems and techniques) used by investigators in this field to study processing of individual pre-mRNAS:
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Affiliation(s)
- H Lou
- Department of Genetics and the Ireland Cancer Center, Case Western Reserve University, School of Medicine and University Hospitals of Cleveland, 10900 Euclid Avenue, Cleveland, OH 44106-4955, USA.
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22
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Kanters SD, Banga JD, Algra A, Frijns RC, Beutler JJ, Fijnheer R. Plasma levels of cellular fibronectin in diabetes. Diabetes Care 2001; 24:323-7. [PMID: 11213886 DOI: 10.2337/diacare.24.2.323] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Cellular fibronectin is an endothelium-derived protein involved in subendothelial matrix assembly. Elevated plasma levels of cellular fibronectin therefore reflect loss of endothelial cell polarization or injury to blood vessels. Consequently, elevated plasma levels of circulating cellular fibronectin have been described in clinical syndromes with vascular damage, although not in diabetes or atherosclerosis. RESEARCH DESIGN AND METHODS We determined fibronectin levels in 52 patients with type 1 diabetes, 50 patients with type 2 diabetes, 54 patients with a history of ischemic stroke, 23 patients with renal artery stenosis, and 64 healthy subjects. RESULTS Circulating cellular fibronectin was significantly elevated in patients with diabetes (4.3 +/- 2.8 microg/ml) compared with patients with ischemic stroke (2.0 +/- 0.9 microg/ml), patients with renovascular hypertension (1.7 +/- 1.1 microg/ml), and healthy subjects (1.4 +/- 0.6 microg/ml). Patients with diabetes and at least one cardiovascular risk factor had an almost 2.5-fold increase in cellular fibronectin compared with diabetic subjects without such a risk factor. In multivariate regression analysis, higher triglycerides, current or past cigarette smoking, and higher urinary albumin excretion were independently associated with an increase in circulating cellular fibronectin in diabetes. CONCLUSIONS These results suggest that circulating cellular fibronectin may be a marker protein for endothelial cell activation, especially in diabetes. Prospective studies are needed to explore this possibility
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Affiliation(s)
- S D Kanters
- Department of Internal Medicine, University Medical Center, Utrecht, The Netherlands
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23
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Boyle DL, Shi Y, Gay S, Firestein GS. Regulation of CS1 fibronectin expression and function by IL-1 in endothelial cells. Cell Immunol 2000; 200:1-7. [PMID: 10716877 DOI: 10.1006/cimm.2000.1610] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
VLA-4 is a critical adhesion molecule that regulates mononuclear cell trafficking to sites of inflammation. VCAM-1 is a primary ligand of VLA-4, although alternatively spliced fibronectin (FN) containing the CS1 region (CS1 FN) also binds to VLA-4. CS1 FN is expressed by rheumatoid arthritis (RA) synovial endothelial cells, but the factors that regulate CS1 FN expression are not known. We incubated human umbilical vein endothelial cells (HUVEC) with IL-1 (0.1-10 ng/ml) for 8-48 h and determined total FN and CS1 FN mRNA by Northern blot analysis. Both were constitutively expressed by HUVEC, and IL-1 increased total FN mRNA and the CS1-containing isoform (P < 0.05). IL-1 also increased CS1 FN protein expression on HUVEC as determined by Western blot analysis. An adhesion assay using (51)Cr-labeled Jurkat cells and IL-1-stimulated HUVEC was used to determine if IL-1-induced CS1 FN mediates cell binding. Cyclic CS1 peptide (10 microg/ml) blocked 49 +/- 5% of IL-1-induced Jurkat cell adhesion to HUVEC (P < 0.01), whereas anti-VCAM-1 antibody inhibited binding by only 35 +/- 5% (P < 0.01). CS1 peptide and anti-VCAM antibody treatment were not additive (50 +/- 7% inhibition), and 38 +/- 6% of new VLA-4-mediated adhesion to IL-1-treated HUVEC was due to an increase in CS1 FN. These data show that IL-1 increases CS1 FN expression by HUVEC and increases CS1-mediated cell adhesion. CS1 mimetics might have therapeutic efficacy by blocking recruitment of VLA-4-bearing cells.
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Affiliation(s)
- D L Boyle
- Division of Rheumatology, UCSD School of Medicine, La Jolla, California 92093-0656, USA
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24
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25
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Abstract
PURPOSE Increased TGF-beta1 protein expression in tunica albuginea has been found to be associated with Peyronie's disease. The present study is designed to investigate whether surgical trauma induces TGF-beta up-regulation and histological changes in rat penis. MATERIALS AND METHODS Thirty-two adult male Sprague-Dawley rats were divided into two groups. The first group (n=24) underwent incision and suture repair of the tunica albuginea of the penis. The second group (n=8) received sham surgery (incision of the penile skin and underlying fascia) as the control group. The trauma-induced group was divided into four subgroups in which the rats were euthanized at 6 hours (n=6), 1 day (n=6), 3 days (n=6), and 8 weeks (n=6). Two sham-operated (control) animals were also euthanized at each of the above time points. All tunical tissues from the trauma-induced and sham-operated rats were collected and examined histologically using Trichrome and Hart elastic fiber stain. Electron microscopy was used to study the ultrastructural changes of both trauma induced and control specimens. Western blotting technique was performed to study TGF-beta protein expression in both experimental and sham-operated groups. RESULTS Tissue edema and hemorrhage between collagen bundles are noted in the experimental groups after 6 hours, 1 day and 3 days. At 8 weeks the most prominent changes observed were inflammatory cellular infiltration and disorganization of the collagen bundles. In the control group the tunica albuginea retains normal wavy regular appearance in all rats. This histological analysis is similar to the reported description of histological features of the acute phase of Peyronie's disease. Electron microscopy showed packed collagen bundles in the trauma-induced group with normal appearing elastic fibers. No abnormal change was detected in the control group. Immunoblot results revealed remarkable TGF-beta1 protein expression in 1, 5, 3, and 0 rats of trauma induced subgroups after 6 hours, 1 day, 3 days, and 8 weeks respectively. No TGF-beta1 protein expression in any rats in the control group was detected. No significant TGF-beta2 or TGF-beta3 protein expression was observed either in the trauma induced group or in the control group. CONCLUSION Trauma can induce histological changes similar to the acute phase of Peyronie's disease but not the overt picture of the chronic phase of Peyronie's disease. It can also result in an early but transient up-regulation of TGF-beta1 protein expression in the rat penis. We conclude that surgical incisional trauma does not result in Peyronie's disease-like changes in the tunica.
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Affiliation(s)
- A I El-Sakka
- Department of Urology, University of California School of Medicine, San Francisco 94143-0738, USA
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26
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Rennard SI. Repair of the airway epithelium: Potential opportunities for therapeutic intervention in airway disease. Allergol Int 1998. [DOI: 10.2332/allergolint.47.91] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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27
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El-Sakka AI, Hassoba HM, Chui RM, Bhatnagar RS, Dahiya R, Lue TF. An animal model of Peyronie's-like condition associated with an increase of transforming growth factor beta mRNA and protein expression. J Urol 1997; 158:2284-90. [PMID: 9366377 DOI: 10.1016/s0022-5347(01)68236-3] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE Transforming growth factor beta (TGF-beta) is involved in numerous vital processes including tissue fibrosis. Our objective was to study the role of TGF-beta in the induction of a Peyronie's-like condition and to produce an animal model for the further study of Peyronie's disease. MATERIALS AND METHODS Twenty-four adult male Sprague-Dawley rats were divided into two groups. Different concentrations of cytomodulin, a synthetic heptopeptide with TGF-beta-like activity, were injected into the tunica of each rat from the first group (n = 18). Rats in the second group (n = 6) received saline injections as a control. The tunical tissues were taken after 3 days, 2 weeks, and 6 weeks and were examined using Hart and Trichrome stains. In the same tissue samples, TGF-beta mRNA and protein expression were studied. RESULTS Histological alterations were observed in 15 out of 18 cytomodulin-injected rats, especially in tissue examined after 6 weeks. The most prominent changes were chronic cellular infiltration, focal and diffuse elastosis, thickening, disorganization and clumping of the collagen bundles. Results from immunoblot revealed remarkable TGF-beta1 protein expression in all the cytomodulin-injected rats only after 2 and 6 weeks. No remarkable TGF-beta2 or TGF-beta3 protein expression was observed. TGF-beta1 mRNA expression in the cytomodulin-injected rats was noticed in rats injected with higher concentrations after 3 days, while it was expressed in all rats after 2 weeks. There was no expression in the control group after either 3 days or 2 weeks. CONCLUSIONS Cytomodulin can induce Peyronie's-like condition in the rat penis, which may explain the role of TGF-beta in the pathogenesis of Peyronie's disease.
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Affiliation(s)
- A I El-Sakka
- Department of Urology, University of California School of Medicine, San Francisco 94143-0738, USA
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28
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Cam Y, Lesot H, Colosetti P, Ruch JV. Distribution of transforming growth factor beta1-binding proteins and low-affinity receptors during odontoblast differentiation in the mouse. Arch Oral Biol 1997; 42:385-91. [PMID: 9233848 DOI: 10.1016/s0003-9969(97)00017-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Transforming growth factor-beta1 (TGF-beta1) was immunolocalized within differentiated odontoblasts and ameloblasts while LAP-beta1 was detected at the apicol pole of odonotoblasts and ameloblasts and in predentine. Anti-LAP-beta1 antibodies also stained the epithelial-mesenchymal junction (EMJ). Decorin was immunolocalized in young functional odonotoblasts and in both predentine and dentine. Biglycan was similarly distributed but absent from dentine. Immunostaining with anti-latent TGF-beta1 binding protein-1 (LTBP-1) showed fibrillar structures located at the EMJ and between predontoblasts and odontoblasts; at older states staining was restricted to the dental papilla and sac. Thus differentiated odonotoblasts express TGF-beta1 and in a more restricted manner decorin, biglycan and LAP-beta1; it can be assumed that TGF-beta1 is able to interact with the three molecules present in predentine. Earlier, LTBP-1 and LAP-beta1, both present at the EMJ, may contribute to odontoblast differentiation.
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Affiliation(s)
- Y Cam
- Institut de Biologie Médicale, INSERM U424, Faculté de Médecine 11, Strasbourg, France
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29
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Abstract
Asthma is classically defined in terms of reversible airflow obstruction. It is now recognized that histologic abnormalities, including inflammation, are a regular feature of asthma. In addition, alterations of the structural elements of the airway wall occur regularly in asthma. These alterations include a thickened basal lamina comprised of interstitial collagens as well as alterations in the mesenchymal cell population with an accumulation of myofibroblasts. It seems likely that these connective tissue alterations in the airway wall contribute to the physiologic abnormalities of asthma. While controversial, the long-term physiologic sequela of asthma may depend in large part on these changes. The biochemical and cellular basis that leads to these changes is, as yet, unknown, but recent studies suggest that a variety of cells in the airway, including inflammatory cells and the cells of the airway epithelium, may participate in regulating this response.
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Affiliation(s)
- S I Rennard
- University of Nebraska Medical Center, Pulmonary and Critical Care Medicine Section, Omaha 68198-5300, USA
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Berndt A, Kosmehl H, Mandel U, Gabler U, Luo X, Celeda D, Zardi L, Katenkamp D. TGFβ and bFGF synthesis and localization in Dupuytren's disease (nodular palmar fibromatosis) relative to cellular activity, myofibroblast phenotype and oncofetal variants of fibronectin. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf02389692] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Affiliation(s)
- S I Rennard
- University of Nebraska Medical Center, Omaha
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32
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Cardellini P, Polo C, Coral S. Suramin and heparin: aspecific inhibitors of mesoderm induction in the Xenopus laevis embryo. Mech Dev 1994; 45:73-87. [PMID: 8186150 DOI: 10.1016/0925-4773(94)90054-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Xenopus embryos in solutions containing suramin show a dose-dependent decrease in the formation of dorsoanterior structures. Continuous treatment with 1 mM suramin produces embryos without mesodermal derivatives but with mesenchymal cells. Brief immersions of 20 min were used to determine the most sensitive stages and to establish dose-effect curves: a 20 min treatment with 3 mM suramin at stages 7-8.5 produces blastula-like embryos, never classified before, with atypical epidermis, cells full of yolk and mesenchyme in between. The lack of dorsal mesoderm was confirmed by an RNase protection assay with alpha-cardiac actin probe. Heparin also causes a reduction in dorsal structures, but its action is weaker and and there are also strong toxic effects such as superficial cell dissociation. The effect of heparin is dose-dependent and brief immersions show a very sensitive period around stage 6.5. The lowest DAI obtained is 1.5, an extremely microcephalic embryo with forked tail codes, a stocky notochord, and abnormally shaped, abundant neural tissue. Immunofluorescence shows that the distribution of fibronectin-containing fibrils is normal in heparin-treated embryos, whereas there are no such fibrils in suramin-treated embryos at control stage 12.
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Affiliation(s)
- P Cardellini
- Dipartimento di Biologia, Università degli Studi di Padova, Italy
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33
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Schor SL. Cytokine control of cell motility: modulation and mediation by the extracellular matrix. PROGRESS IN GROWTH FACTOR RESEARCH 1994; 5:223-48. [PMID: 7919226 DOI: 10.1016/0955-2235(94)90007-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cytokines are multifunctional regulators of cell behaviour affecting such diverse activities as cell proliferation, gene expression and motility. Matrix macromolecules influence a similarly wide range of cell functions. A review of the available literature suggests that cytokines may affect cell motility by (a) directly influencing the motility apparatus, and (b) indirectly as a consequence of the altered expression of genes coding for matrix macromolecules, their respective cell surface receptors and matrix degrading enzymes and their inhibitors. Conversely, the composition and supramolecular organisation of the matrix plays a central role in defining cellular response to potentially multifunctional cytokines. Such complex and reciprocal interactions between cytokines and the matrix elicit both positive and negative reiterative feedback loops which must be taken into account when interpreting the results of migration assays in vitro and extrapolating them to in vivo processes.
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Affiliation(s)
- S L Schor
- School of Biological Sciences, The Medical School, University of Manchester, U.K
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Kaneto H, Morrissey J, Klahr S. Increased expression of TGF-beta 1 mRNA in the obstructed kidney of rats with unilateral ureteral ligation. Kidney Int 1993; 44:313-21. [PMID: 8377375 DOI: 10.1038/ki.1993.246] [Citation(s) in RCA: 232] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Renal interstitial fibrosis is a common consequence of chronic ureteral obstruction. While several cytokines may initiate fibrogenesis, TGF-beta is considered to be a major stimulating factor. It has been reported that TGF-beta 1 regulates extracellular matrix (ECM) synthesis, that thromboxane (Tx) stimulates ECM protein synthesis, and that angiotensin II (Ang II) increases expression of TGF-beta 1 mRNA in rat aortic smooth muscle cells. Therefore, we measured TGF-beta 1 mRNA expression by reverse transcription coupled with polymerase chain reaction in renal cortex of rats with unilateral ureteral obstruction (UUO) to determine whether Ang II and/or Tx stimulates increases in TGF-beta 1 mRNA. TGF-beta 1 mRNA levels in contralateral kidneys of rats with UUO did not change significantly during 14 days of obstruction, while in the obstructed kidney TGF-beta 1 mRNA levels were increased significantly after three days as compared to the control (unoperated rats) kidneys. The increase in TGF-beta 1 mRNA expression in the obstructed kidney cortex was found in tubular cells rather than glomeruli. OKY-046, an inhibitor of thromboxane synthase, did not affect the changes in TGF-beta 1 mRNA in the obstructed kidney. Enalapril, an angiotensin I converting enzyme inhibitor, significantly blunted but did not completely abrogate the increase in TGF-beta 1 mRNA. These data suggest that in obstruction TGF-beta 1 is increased at the transcriptional level and thus may play a role in initiating fibrogenesis in obstructive nephropathy. The effect of thromboxane on extracellular matrix synthesis does not appear to be mediated by TGF-beta 1.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- H Kaneto
- Department of Medicine, Jewish Hospital of St. Louis, Washington University Medical Center, Missouri
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35
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Linnala A, Balza E, Zardi L, Virtanen I. Human amnion epithelial cells assemble tenascins and three fibronectin isoforms in the extracellular matrix. FEBS Lett 1993; 317:74-8. [PMID: 7679082 DOI: 10.1016/0014-5793(93)81494-k] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Monoclonal antibodies (MAb) were used to show that cultured human amnion epithelial (HuA) cells produce tenascins (Tn) and isoforms of cellular fibronectin (cFn). Tn polypeptides of M(r) 280,000 and 190,000, assembled into extracellular matrix (ECM) but not secreted into the culture medium by HuA cells, were electrophoretically similar to those produced by human fibroblasts as revealed with domain-specific MAbs. The results suggested that most Fn produced by HuA cells contained the extradomain (ED) A and an oncofetal domain but only a minor fraction EDB. In immunofluorescence Tn and Fn were seen in different cytoplasmic granules upon monensin-induced intracellular accumulation. Tn appeared to be deposited in the ECM in colocalization with Fn but distinctly slower. The present results show that cultured normal human epithelial cells synthesize Tn and three isoforms of cFn and secrete them by using different cytoplasmic pathways.
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Affiliation(s)
- A Linnala
- Department of Anatomy, University of Helsinki, Finland
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36
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Border WA, Noble NA, Yamamoto T, Harper JR, Yamaguchi YU, Pierschbacher MD, Ruoslahti E. Natural inhibitor of transforming growth factor-beta protects against scarring in experimental kidney disease. Nature 1992; 360:361-4. [PMID: 1280332 DOI: 10.1038/360361a0] [Citation(s) in RCA: 741] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The central pathological feature of human kidney disease that leads to kidney failure is the accumulation of extracellular matrix in glomeruli. Overexpression of transforming growth factor-beta (TGF-beta) underlies the accumulation of pathological matrix in experimental glomerulonephritis. Administration of an antibody raised against TGF-beta to glomerulonephritic rats suppresses glomerular matrix production and prevents matrix accumulation in the injured glomeruli. One of the matrix components induced by TGF-beta, the proteoglycan decorin, can bind TGF-beta and neutralize its biological activity, so decorin may be a natural regulator of TGF-beta (refs 3, 4). We tested whether decorin could antagonize the action of TGF-beta in vivo using the experimental glomerulonephritis model. We report here that administration of decorin inhibits the increased production of extracellular matrix and attenuates manifestations of disease, confirming our hypothesis. On the basis of our results, decorin may eventually prove to be clinically useful in diseases associated with overproduction of TGF-beta.
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Affiliation(s)
- W A Border
- Division of Nephrology, University of Utah School of Medicine, Salt Lake City 84132
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37
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Transforming growth factor beta differentially regulates expression of integrin subunits in guinea pig airway epithelial cells. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41941-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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38
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Noble NA, Harper JR, Border WA. In vivo interactions of TGF-beta and extracellular matrix. PROGRESS IN GROWTH FACTOR RESEARCH 1992; 4:369-82. [PMID: 1340215 DOI: 10.1016/0955-2235(92)90017-c] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
TGF-beta, a multifunctional cytokine, plays an important role in embryogenesis and in regulating repair and remodeling following tissue injury. Many of the biological actions of TGF-beta are mediated by widespread effects on deposition of extracellular matrix. TGF-beta stimulates the synthesis of individual matrix components including proteoglycans, collagens and glycoproteins. TGF-beta also blocks matrix degradation by decreasing the synthesis of proteases and increasing the synthesis of protease inhibitors. Finally, TGF-beta increases the synthesis of matrix receptors and alters their relative proportions on the surface of cells in a manner that could facilitate adhesion to matrix. All of these events have largely been demonstrated in vitro in cultured cells. In an experimental model of glomerulonephritis we have shown that TGF-beta is responsible for the accumulation of pathological matrix in the glomeruli following immunological injury. Furthermore, all three of TGF-beta's actions on extracellular matrix--increased synthesis, decreased degradation and modulation of receptors--have now been documented to be involved in matrix deposition in vivo in this model. Administration of the proteoglycan decorin suppressed TGF-beta-induced matrix deposition in the nephritic glomeruli, thus confirming a physiological role for decorin as a regulator of TGF-beta. Inhibitors of TGF-beta may be important future drugs in treating fibrotic diseases caused by overproduction of TGF-beta.
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Affiliation(s)
- N A Noble
- Division of Nephrology, University of Utah School of Medicine, Salt Lake City 84132
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