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Johnson BB, Cosson MV, Tsansizi LI, Holmes TL, Gilmore T, Hampton K, Song OR, Vo NTN, Nasir A, Chabronova A, Denning C, Peffers MJ, Merry CLR, Whitelock J, Troeberg L, Rushworth SA, Bernardo AS, Smith JGW. Perlecan (HSPG2) promotes structural, contractile, and metabolic development of human cardiomyocytes. Cell Rep 2024; 43:113668. [PMID: 38198277 DOI: 10.1016/j.celrep.2023.113668] [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: 05/22/2023] [Revised: 11/01/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024] Open
Abstract
Perlecan (HSPG2), a heparan sulfate proteoglycan similar to agrin, is key for extracellular matrix (ECM) maturation and stabilization. Although crucial for cardiac development, its role remains elusive. We show that perlecan expression increases as cardiomyocytes mature in vivo and during human pluripotent stem cell differentiation to cardiomyocytes (hPSC-CMs). Perlecan-haploinsuffient hPSCs (HSPG2+/-) differentiate efficiently, but late-stage CMs have structural, contractile, metabolic, and ECM gene dysregulation. In keeping with this, late-stage HSPG2+/- hPSC-CMs have immature features, including reduced ⍺-actinin expression and increased glycolytic metabolism and proliferation. Moreover, perlecan-haploinsuffient engineered heart tissues have reduced tissue thickness and force generation. Conversely, hPSC-CMs grown on a perlecan-peptide substrate are enlarged and display increased nucleation, typical of hypertrophic growth. Together, perlecan appears to play the opposite role of agrin, promoting cellular maturation rather than hyperplasia and proliferation. Perlecan signaling is likely mediated via its binding to the dystroglycan complex. Targeting perlecan-dependent signaling may help reverse the phenotypic switch common to heart failure.
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Affiliation(s)
- Benjamin B Johnson
- Centre for Metabolic Health, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Marie-Victoire Cosson
- The Francis Crick Institute, London NW1 1AT, UK; NHLI, Imperial College London, London, UK
| | - Lorenza I Tsansizi
- The Francis Crick Institute, London NW1 1AT, UK; NHLI, Imperial College London, London, UK
| | - Terri L Holmes
- Centre for Metabolic Health, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK
| | | | - Katherine Hampton
- Centre for Metabolic Health, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Ok-Ryul Song
- The Francis Crick Institute, London NW1 1AT, UK; High-Throughput Screening Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Nguyen T N Vo
- School of Medicine, Regenerating and Modelling Tissues, Biodiscovery Institute, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Aishah Nasir
- School of Medicine, Regenerating and Modelling Tissues, Biodiscovery Institute, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Alzbeta Chabronova
- Institute of Life Course and Medical Sciences, William Henry Duncan Building, 6 West Derby Street, Liverpool L7 8TX, UK
| | - Chris Denning
- School of Medicine, Regenerating and Modelling Tissues, Biodiscovery Institute, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Mandy J Peffers
- Institute of Life Course and Medical Sciences, William Henry Duncan Building, 6 West Derby Street, Liverpool L7 8TX, UK
| | - Catherine L R Merry
- School of Medicine, Regenerating and Modelling Tissues, Biodiscovery Institute, University Park, University of Nottingham, Nottingham NG7 2RD, UK; Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - John Whitelock
- School of Medicine, Regenerating and Modelling Tissues, Biodiscovery Institute, University Park, University of Nottingham, Nottingham NG7 2RD, UK; Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Linda Troeberg
- Centre for Metabolic Health, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Stuart A Rushworth
- Centre for Metabolic Health, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Andreia S Bernardo
- The Francis Crick Institute, London NW1 1AT, UK; NHLI, Imperial College London, London, UK.
| | - James G W Smith
- Centre for Metabolic Health, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK.
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Trinh K, Julovi SM, Rogers NM. The Role of Matrix Proteins in Cardiac Pathology. Int J Mol Sci 2022; 23:ijms23031338. [PMID: 35163259 PMCID: PMC8836004 DOI: 10.3390/ijms23031338] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/15/2022] [Accepted: 01/21/2022] [Indexed: 02/06/2023] Open
Abstract
The extracellular matrix (ECM) and ECM-regulatory proteins mediate structural and cell-cell interactions that are crucial for embryonic cardiac development and postnatal homeostasis, as well as organ remodeling and repair in response to injury. These proteins possess a broad functionality that is regulated by multiple structural domains and dependent on their ability to interact with extracellular substrates and/or cell surface receptors. Several different cell types (cardiomyocytes, fibroblasts, endothelial and inflammatory cells) within the myocardium elaborate ECM proteins, and their role in cardiovascular (patho)physiology has been increasingly recognized. This has stimulated robust research dissecting the ECM protein function in human health and disease and replicating the genetic proof-of-principle. This review summarizes recent developments regarding the contribution of ECM to cardiovascular disease. The clear importance of this heterogeneous group of proteins in attenuating maladaptive repair responses provides an impetus for further investigation into these proteins as potential pharmacological targets in cardiac diseases and beyond.
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Affiliation(s)
- Katie Trinh
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (K.T.); (S.M.J.)
- Faculty of Medicine and Health Sydney, School of Medical Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Sohel M. Julovi
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (K.T.); (S.M.J.)
- Faculty of Medicine and Health Sydney, School of Medical Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Natasha M. Rogers
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (K.T.); (S.M.J.)
- Faculty of Medicine and Health Sydney, School of Medical Sciences, The University of Sydney, Sydney, NSW 2006, Australia
- Renal and Transplantation Medicine, Westmead Hospital, Westmead, NSW 2145, Australia
- Correspondence:
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Fibrosis, the Bad Actor in Cardiorenal Syndromes: Mechanisms Involved. Cells 2021; 10:cells10071824. [PMID: 34359993 PMCID: PMC8307805 DOI: 10.3390/cells10071824] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/08/2021] [Accepted: 07/13/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiorenal syndrome is a term that defines the complex bidirectional nature of the interaction between cardiac and renal disease. It is well established that patients with kidney disease have higher incidence of cardiovascular comorbidities and that renal dysfunction is a significant threat to the prognosis of patients with cardiac disease. Fibrosis is a common characteristic of organ injury progression that has been proposed not only as a marker but also as an important driver of the pathophysiology of cardiorenal syndromes. Due to the relevance of fibrosis, its study might give insight into the mechanisms and targets that could potentially be modulated to prevent fibrosis development. The aim of this review was to summarize some of the pathophysiological pathways involved in the fibrotic damage seen in cardiorenal syndromes, such as inflammation, oxidative stress and endoplasmic reticulum stress, which are known to be triggers and mediators of fibrosis.
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Burke RM, Burgos Villar KN, Small EM. Fibroblast contributions to ischemic cardiac remodeling. Cell Signal 2021; 77:109824. [PMID: 33144186 PMCID: PMC7718345 DOI: 10.1016/j.cellsig.2020.109824] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 12/23/2022]
Abstract
The heart can respond to increased pathophysiological demand through alterations in tissue structure and function 1 . This process, called cardiac remodeling, is particularly evident following myocardial infarction (MI), where the blockage of a coronary artery leads to widespread death of cardiac muscle. Following MI, necrotic tissue is replaced with extracellular matrix (ECM), and the remaining viable cardiomyocytes (CMs) undergo hypertrophic growth. ECM deposition and cardiac hypertrophy are thought to represent an adaptive response to increase structural integrity and prevent cardiac rupture. However, sustained ECM deposition leads to the formation of a fibrotic scar that impedes cardiac compliance and can induce lethal arrhythmias. Resident cardiac fibroblasts (CFs) are considered the primary source of ECM molecules such as collagens and fibronectin, particularly after becoming activated by pathologic signals. CFs contribute to multiple phases of post-MI heart repair and remodeling, including the initial response to CM death, immune cell (IC) recruitment, and fibrotic scar formation. The goal of this review is to describe how resident fibroblasts contribute to the healing and remodeling that occurs after MI, with an emphasis on how fibroblasts communicate with other cell types in the healing infarct scar 1 –6 .
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Affiliation(s)
- Ryan M Burke
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA; Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, United States of America
| | - Kimberly N Burgos Villar
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Eric M Small
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA; Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, United States of America; Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, United States of America; Department of Biomedical Engineering, University of Rochester, Rochester, NY 14642, United States of America.
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The Non-Fibrillar Side of Fibrosis: Contribution of the Basement Membrane, Proteoglycans, and Glycoproteins to Myocardial Fibrosis. J Cardiovasc Dev Dis 2019; 6:jcdd6040035. [PMID: 31547598 PMCID: PMC6956278 DOI: 10.3390/jcdd6040035] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/16/2019] [Accepted: 09/18/2019] [Indexed: 02/07/2023] Open
Abstract
The extracellular matrix (ECM) provides structural support and a microenvironmentfor soluble extracellular molecules. ECM is comprised of numerous proteins which can be broadly classified as fibrillar (collagen types I and III) and non-fibrillar (basement membrane, proteoglycans, and glycoproteins). The basement membrane provides an interface between the cardiomyocytes and the fibrillar ECM, while proteoglycans sequester soluble growth factors and cytokines. Myocardial fibrosis was originally only linked to accumulation of fibrillar collagens, but is now recognized as the expansion of the ECM including the non-fibrillar ECM proteins. Myocardial fibrosis can be reparative to replace the lost myocardium (e.g., ischemic injury or myocardial infarction), or can be reactive resulting from pathological activity of fibroblasts (e.g., dilated or hypertrophic cardiomyopathy). Contribution of fibrillar collagens to fibrosis is well studied, but the role of the non-fibrillar ECM proteins has remained less explored. In this article, we provide an overview of the contribution of the non-fibrillar components of the extracellular space of the heart to highlight the potential significance of these molecules in fibrosis, with direct evidence for some, although not all of these molecules in their direct contribution to fibrosis.
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Emerging roles of proteoglycans in cardiac remodeling. Int J Cardiol 2018; 278:192-198. [PMID: 30528626 DOI: 10.1016/j.ijcard.2018.11.125] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 11/12/2018] [Accepted: 11/27/2018] [Indexed: 02/07/2023]
Abstract
Cardiac remodeling is the response of the heart to a range of pathological stimuli. Cardiac remodeling is initially adaptive; however, if sustained, it ultimately causes adverse clinical outcomes. Cardiomyocyte loss or hypertrophy, inflammation and fibrosis are hallmarks of cardiac remodeling. Proteoglycans, which are composed of glycosaminoglycans and a core protein, are a non-structural component of the extracellular matrix. The lack of proteoglycans results in cardiovascular defects during development. Moreover, emerging evidence has indicated that proteoglycans act as significant modifiers in ischemia and pressure overload-related cardiac remodeling. Proteoglycans may also provide novel therapeutic strategies for further improvement in the prognosis of cardiovascular diseases.
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Jourdan-LeSaux C, Zhang J, Lindsey ML. Extracellular matrix roles during cardiac repair. Life Sci 2010; 87:391-400. [PMID: 20670633 PMCID: PMC2946433 DOI: 10.1016/j.lfs.2010.07.010] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 06/30/2010] [Accepted: 07/16/2010] [Indexed: 02/06/2023]
Abstract
The cardiac extracellular matrix (ECM) provides a platform for cells to maintain structure and function, which in turn maintains tissue function. In response to injury, the ECM undergoes remodeling that involves synthesis, incorporation, and degradation of matrix proteins, with the net outcome determined by the balance of these processes. The major goals of this review are a) to serve as an initial resource for students and investigators new to the cardiac ECM remodeling field, and b) to highlight a few of the key exciting avenues and methodologies that have recently been explored. While we focus on cardiac injury and responses of the left ventricle (LV), the mechanisms reviewed here have pathways in common with other wound healing models.
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Affiliation(s)
- Claude Jourdan-LeSaux
- Division of Cardiology, Department of Medicine, The University of Texas Health Science Center at San Antonio
| | - Jianhua Zhang
- Division of Cardiology, Department of Medicine, The University of Texas Health Science Center at San Antonio
| | - Merry L. Lindsey
- Division of Cardiology, Department of Medicine, The University of Texas Health Science Center at San Antonio
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Preventive Effect of Low Molecular Weight Glycosaminoglycan from Amussium pleuronectus (Linne) on Oxidative Injury and Cellular Abnormalities in Isoproterenol-Induced Cardiotoxicity in Wistar Rats. Appl Biochem Biotechnol 2009; 162:43-51. [DOI: 10.1007/s12010-009-8750-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 08/10/2009] [Indexed: 11/26/2022]
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Sezaki S, Hirohata S, Iwabu A, Nakamura K, Toeda K, Miyoshi T, Yamawaki H, Demircan K, Kusachi S, Shiratori Y, Ninomiya Y. Thrombospondin-1 is induced in rat myocardial infarction and its induction is accelerated by ischemia/reperfusion. Exp Biol Med (Maywood) 2005; 230:621-30. [PMID: 16179730 DOI: 10.1177/153537020523000904] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Thrombospondin-1 (TSP-1) is a multifunctional, rapid-turnover matricellular protein. Recent studies demonstrated that TSP-1 has a role in regulating inflammatory reactions. Myocardial infarction (MI) is associated with an inflammatory response, ultimately leading to healing and scar formation. In particular, an enhanced inflammatory reaction and a massive accumulation of monocytes/macrophages is seen with reperfusion after MI. To examine the role of TSP-1 in MI, we isolated rat TSP-1 complementary DNA (cDNA) and analyzed the level and distribution of the mRNA expression. In infarcted rat hearts, TSP-1 mRNA increased markedly at 6 and 12 hrs after coronary artery ligation (27.97 +/- 3.40-fold and 22.77 +/- 1.83-fold, respectively, compared with sham-operated hearts). Western blot analysis revealed that TSP-1 protein was transiently induced in the infarcted heart. Using in situ hybridization analysis, TSP-1 mRNA signals were observed in the infiltrating cells at the border area of infarction. We then examined the effect of ischemia/reperfusion (I/R) on TSP-1 mRNA induction in the rats with infarcted hearts. Quantitative reverse transcriptase polymerase chain reaction (RT-PCR) demonstrated that I/R enhanced the TSP-1 mRNA expression approximately 4-fold, as compared with the level in the permanently ligated heart. Finally, we examined the effect of TSP-1 on proinflammatory cytokine release in mononuclear cells. The releases of interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) from human mononuclear cells were enhanced by TSP-1 in a dose-dependent manner. Thus, the immediate and marked increase of TSP-1 expression suggests that TSP-1 has an inflammatory-associated role in MI.
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Affiliation(s)
- Satoshi Sezaki
- Department of Medicine and Medical Science, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan
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Melrose J, Smith S, Whitelock J. Perlecan immunolocalizes to perichondrial vessels and canals in human fetal cartilaginous primordia in early vascular and matrix remodeling events associated with diarthrodial joint development. J Histochem Cytochem 2004; 52:1405-13. [PMID: 15505335 PMCID: PMC3957814 DOI: 10.1369/jhc.4a6261.2004] [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: 11/22/2022] Open
Abstract
The aim of this study was to ascertain how perlecan was localized in human fetal cartilaginous joint rudiment tissues. Perlecan was immunolocalized in human fetal (12-14-week-old) toe, finger, knee, elbow, shoulder, and hip joint rudiments using a monoclonal antibody to domain-1 of perlecan (MAb A76). Perlecan had a widespread distribution in the cartilaginous joint rudiments and growth plates and was also prominent in a network of convoluted hairpin loop-type vessels at the presumptive articulating surfaces of joints. Perlecan was also present in small perichondrial venules and arterioles along the shaft of the developing long bones, small blood vessels in the synovial lining and joint capsules, and in distinctive arrangements of cartilage canals in the knee, elbow, shoulder, and hip joint rudiments. Perlecan was notably absent from CD-31-positive metaphyseal vessels in the hip, knee, shoulder, and fingers. These vessels may have a role in the nutrition of the expanding cell populations in these developing joint tissues and in the establishment of the secondary centers of ossification in the long bones, which is essential for endochondral ossification.
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Affiliation(s)
- James Melrose
- Institute of Bone and Joint Research, Level 5, University of Sydney, Royal North Shore Hospital, St Leonards, NSW 2065, Australia.
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Affiliation(s)
- Albert J Sinusas
- Department of Medicine and Diagnostic Radiology, Yale University School of Medicine, New Haven, CT 06520-8017, USA.
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Drobnik J, Szczepanowska A, Dabrowski R. Temporary augmentation of glycosaminoglycans content in the heart after left coronary artery ligation. ACTA ACUST UNITED AC 2004; 11:35-39. [PMID: 15177514 DOI: 10.1016/j.pathophys.2004.01.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2003] [Revised: 12/02/2003] [Accepted: 01/07/2004] [Indexed: 11/24/2022]
Abstract
Introduction: Augmentation of glycosaminoglycans (GAG) in various tissues after injury is well known, however, there is no information about the metabolism of GAG during the heart remodeling after infarction. The study is focused on the changes of total GAG concentrations in the viable myocardium and scar after experimental left coronary artery occlusion. To shed some light on the possible mechanism of the changes, GAG were also evaluated in the skin. Methods: Male Wistar rats were subjected to left coronary artery ligation or to sham operation. After 3, 6 or 12 weeks of follow up the rats were sacrificed and the heart and skin were collected. The heart was cut into parts: right ventricle, septum, viable region of left ventricle and scar. The Farndale method was used for the estimation of GAG in the samples. Results: High level of GAG in the myocardial scar tissue was seen in the 3 weeks of follow up and reached maximum in the 6 weeks and then decreased in week 12. Similar pattern of GAG changes was found in the contractile part of the heart. In both viable part of the left ventricle and septum the peak level of GAG was found in rats 6 weeks after the onset of infarction. Than the content of GAG decreased towards the control level. There was no alteration in the GAG content in the skin and a wall of the right ventricle. Conclusion: Temporary augmentation of GAG content is present not only in myocardium directly injured by ischaemia but also in the viable part of the heart subjected mainly to increased haemodynamic stresses. The local nature of mechanisms responsible for the GAG changes has been postulated.
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Affiliation(s)
- J. Drobnik
- Department of Pathophysiology, Medical University of Lodz, Narutowicza 60, 90-136 Lodz, Poland
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Melrose J, Smith S, Ghosh P, Whitelock J. Perlecan, the multidomain heparan sulfate proteoglycan of basement membranes, is also a prominent component of the cartilaginous primordia in the developing human fetal spine. J Histochem Cytochem 2003; 51:1331-41. [PMID: 14500701 DOI: 10.1177/002215540305101010] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The aim of this study was to localize perlecan in human fetal spine tissues. Human fetal spines (12-20 weeks; n=6) were fixed in either Histochoice or 10% neutral buffered formalin, routinely processed, paraffin-embedded, and 4-microm sagittal sections were cut and stained with toluidine blue, H&E, and von Kossa. Perlecan, types I, II, IV, and X collagen, CD-31, aggrecan core protein, and native and delta-HS 4, 5 hexuronate stub epitopes were immunolocalized. Toluidine blue staining visualized the cartilaginous vertebral body (VB) rudiments and annular lamellae encompassing the nucleus pulposus (NP). Von Kossa staining identified the VB primary center of ossification. Immunolocalization of type IV collagen, CD-31, and perlecan delineated small blood vessels in the outer annulus fibrosus (AF) and large canals deep within the VBs. Perlecan and type X collagen were also prominently expressed by the hypertrophic vertebral growth plate chondrocytes. Aggrecan was extracellularly distributed in the intervertebral disk (IVD) with intense staining in the posterior AF. Notochordal tissue stained strongly for aggrecan but negatively for perlecan and types I and II collagen. Type I collagen was prominent in the outer AF and less abundant in the NP, while type II collagen was localized throughout the IVD and VB. The immunolocalization patterns observed indicated key roles for perlecan in vasculogenic, chondrogenic, and endochondral ossification processes associated with spinal development.
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Affiliation(s)
- James Melrose
- The Institute of Bone and Joint Research, The University of Sydney, (Department of Surgery) at the Royal North Shore Hospital of Sydney, St. Leonards, Australia.
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