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Meng JH, Huang YB, Long J, Cai QC, Qiao X, Zhang QL, Zhang LD, Yan X, Jing R, Liu XS, Zhou SJ, Yuan YS, Yin-Chen Ma, Zhou LX, Peng NN, Li XC, Cai CH, Tang HM, Martins AF, Jiang JX, Kai-Jun Luo. Innexin hemichannel activation by Microplitis bicoloratus ecSOD monopolymer reduces ROS. iScience 2024; 27:109469. [PMID: 38577101 PMCID: PMC10993139 DOI: 10.1016/j.isci.2024.109469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 01/31/2024] [Accepted: 03/07/2024] [Indexed: 04/06/2024] Open
Abstract
The extracellular superoxide dismutases (ecSODs) secreted by Microplitis bicoloratus reduce the reactive oxygen species (ROS) stimulated by the Microplitis bicoloratus bracovirus. Here, we demonstrate that the bacterial transferase hexapeptide (hexapep) motif and bacterial-immunoglobulin-like (BIg-like) domain of ecSODs bind to the cell membrane and transiently open hemichannels, facilitating ROS reductions. RNAi-mediated ecSOD silencing in vivo elevated ROS in host hemocytes, impairing parasitoid larva development. In vitro, the ecSOD-monopolymer needed to be membrane bound to open hemichannels. Furthermore, the hexapep motif in the beta-sandwich of ecSOD49 and ecSOD58, and BIg-like domain in the signal peptides of ecSOD67 were required for cell membrane binding. Hexapep motif and BIg-like domain deletions induced ecSODs loss of adhesion and ROS reduction failure. The hexapep motif and BIg-like domain mediated ecSOD binding via upregulating innexins and stabilizing the opened hemichannels. Our findings reveal a mechanism through which ecSOD reduces ROS, which may aid in developing anti-redox therapy.
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Affiliation(s)
- Jiang-Hui Meng
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Yong-Biao Huang
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Jin Long
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Qiu-Chen Cai
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72076 Tübingen, Germany
| | - Xin Qiao
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Qiong-Li Zhang
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Li-Dan Zhang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
| | - Xiang Yan
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Rui Jing
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Xing-Shan Liu
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Sai-Jun Zhou
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Yong-Sheng Yuan
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Yin-Chen Ma
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Li-Xiang Zhou
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Nan-Nan Peng
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Xing-Cheng Li
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Cheng-Hui Cai
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - Hong-Mei Tang
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
| | - André F. Martins
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72076 Tübingen, Germany
| | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
| | - Kai-Jun Luo
- School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, P.R. China
- Yunnan International Joint Laboratory of Virology & Immunology, Kunming, Yunnan 650500, P.R. China
- Key Laboratory of the University in Yunnan Province for International Cooperation in Intercellular Communications and Regulations, Yunnan University, Kunming, Yunnan 650500, P.R. China
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Cederlund AA, Aspden RM. Walking on water: revisiting the role of water in articular cartilage biomechanics in relation to tissue engineering and regenerative medicine. JOURNAL OF THE ROYAL SOCIETY, INTERFACE 2022; 19:20220364. [PMID: 35919975 PMCID: PMC9346369 DOI: 10.1098/rsif.2022.0364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The importance, and the difficulty, of generating biosynthetic articular cartilage is widely recognized. Problems arise from obtaining sufficient stiffness, toughness and longevity in the material and integration of new material into existing cartilage and bone. Much work has been done on chondrocytes and tissue macromolecular components while water, which comprises the bulk of the tissue, is largely seen as a passive component; the ‘solid matrix’ is believed to be the main load-bearing element most of the time. Water is commonly seen as an inert filler whose restricted flow through the tissue is believed to be sufficient to generate the properties measured. We propose that this model should be turned on its head. Water comprises 70–80% of the matrix and has a bulk modulus considerably greater than that of cartilage. We suggest that the macromolecular components structure the water to support the loads applied. Here, we shall examine the structure and organization of the main macromolecules, collagen, aggrecan and hyaluronan, and explore how water interacts with their polyelectrolyte nature. This may inform the biosynthetic process by identifying starting points to enable developing tissue properties to guide the cells into producing the appropriate macromolecular composition and structure.
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Affiliation(s)
- Anna A Cederlund
- Aberdeen Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Richard M Aspden
- Aberdeen Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, UK
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Hayes AJ, Melrose J. Aggrecan, the Primary Weight-Bearing Cartilage Proteoglycan, Has Context-Dependent, Cell-Directive Properties in Embryonic Development and Neurogenesis: Aggrecan Glycan Side Chain Modifications Convey Interactive Biodiversity. Biomolecules 2020; 10:E1244. [PMID: 32867198 PMCID: PMC7564073 DOI: 10.3390/biom10091244] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/19/2020] [Accepted: 08/23/2020] [Indexed: 02/06/2023] Open
Abstract
This review examines aggrecan's roles in developmental embryonic tissues, in tissues undergoing morphogenetic transition and in mature weight-bearing tissues. Aggrecan is a remarkably versatile and capable proteoglycan (PG) with diverse tissue context-dependent functional attributes beyond its established role as a weight-bearing PG. The aggrecan core protein provides a template which can be variably decorated with a number of glycosaminoglycan (GAG) side chains including keratan sulphate (KS), human natural killer trisaccharide (HNK-1) and chondroitin sulphate (CS). These convey unique tissue-specific functional properties in water imbibition, space-filling, matrix stabilisation or embryonic cellular regulation. Aggrecan also interacts with morphogens and growth factors directing tissue morphogenesis, remodelling and metaplasia. HNK-1 aggrecan glycoforms direct neural crest cell migration in embryonic development and is neuroprotective in perineuronal nets in the brain. The ability of the aggrecan core protein to assemble CS and KS chains at high density equips cartilage aggrecan with its well-known water-imbibing and weight-bearing properties. The importance of specific arrangements of GAG chains on aggrecan in all its forms is also a primary morphogenetic functional determinant providing aggrecan with unique tissue context dependent regulatory properties. The versatility displayed by aggrecan in biodiverse contexts is a function of its GAG side chains.
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Affiliation(s)
- Anthony J Hayes
- Bioimaging Research Hub, Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, UK
| | - James Melrose
- Raymond Purves Laboratory, Institute of Bone and Joint Research, Kolling Institute of Medical Research, Northern Sydney Local Health District, Royal North Shore Hospital, St. Leonards 2065, NSW, Australia
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, NSW, Australia
- Sydney Medical School, Northern, The University of Sydney, Faculty of Medicine and Health at Royal North Shore Hospital, St. Leonards 2065, NSW, Australia
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Paganini C, Costantini R, Superti-Furga A, Rossi A. Bone and connective tissue disorders caused by defects in glycosaminoglycan biosynthesis: a panoramic view. FEBS J 2019; 286:3008-3032. [PMID: 31286677 DOI: 10.1111/febs.14984] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 05/22/2019] [Accepted: 07/04/2019] [Indexed: 02/06/2023]
Abstract
Glycosaminoglycans (GAGs) are a heterogeneous family of linear polysaccharides that constitute the carbohydrate moiety covalently attached to the protein core of proteoglycans, macromolecules present on the cell surface and in the extracellular matrix. Several genetic disorders of bone and connective tissue are caused by mutations in genes encoding for glycosyltransferases, sulfotransferases and transporters that are responsible for the synthesis of sulfated GAGs. Phenotypically, these disorders all reflect alterations in crucial biological functions of GAGs in the development, growth and homoeostasis of cartilage and bone. To date, up to 27 different skeletal phenotypes have been linked to mutations in 23 genes encoding for proteins involved in GAG biosynthesis. This review focuses on recent genetic, molecular and biochemical studies of bone and connective tissue disorders caused by GAG synthesis defects. These insights and future research in the field will provide a deeper understanding of the molecular pathogenesis of these disorders and will pave the way for developing common therapeutic strategies that might be targeted to a range of individual phenotypes.
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Affiliation(s)
- Chiara Paganini
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Italy
| | - Rossella Costantini
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Italy
| | - Andrea Superti-Furga
- Division of Genetic Medicine, Lausanne University Hospital, University of Lausanne, Switzerland
| | - Antonio Rossi
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Italy
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Hayes AJ, Melrose J. Glycosaminoglycan and Proteoglycan Biotherapeutics in Articular Cartilage Protection and Repair Strategies: Novel Approaches to Visco‐supplementation in Orthobiologics. ADVANCED THERAPEUTICS 2019. [DOI: 10.1002/adtp.201900034] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Anthony J. Hayes
- Bioimaging Research HubCardiff School of BiosciencesCardiff University Cardiff CF10 3AX Wales UK
| | - James Melrose
- Graduate School of Biomedical EngineeringUNSW Sydney Sydney NSW 2052 Australia
- Raymond Purves Bone and Joint Research LaboratoriesKolling Institute of Medical ResearchRoyal North Shore Hospital and The Faculty of Medicine and HealthUniversity of Sydney St. Leonards NSW 2065 Australia
- Sydney Medical SchoolNorthernRoyal North Shore HospitalSydney University St. Leonards NSW 2065 Australia
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Complete sequencing and characterization of equine aggrecan. Vet Comp Orthop Traumatol 2015; 28:79-87. [PMID: 25632964 DOI: 10.3415/vcot-14-05-0069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 09/12/2014] [Indexed: 11/17/2022]
Abstract
OBJECTIVES To fully sequence and characterize equine aggrecan and confirm conservation of major aggrecanase, calpain and matrix metalloproteinase (MMP) cleavage sites. METHODS Reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends were used to generate clones that encompassed the complete equine aggrecan sequence. Clones were sequenced and compared with the equine genome database to determine intron-exon boundaries. RESULTS The aggrecan gene spans over 61 kb on chromosome 1 and is encoded by 17 exons. Two major variants of aggrecan were cloned; one containing 8187 bp (2728 amino acids) and a second sequence of 8061 nucleotides (2686 amino acids). The variation was due to a CS1 domain polymorphism. Both sequences are substantially larger than predicted by the genomic database; 11 CS1 repeat elements are absent in the database sequence. The equine amino acid sequence was compared with human, bovine and murine sequences. Globular domains 1, 2 and 3 are highly conserved (overall identity over 80%). Equine CS1 is considerably larger than in other species and, therefore, is the least conserved domain (an overall amino acid identity of 22%). Previously defined aggrecanase, calpain and MMP cleavage sites were identified. Western blotting of chondrocyte culture samples showed complex post-secretion processing. CLINICAL SIGNIFICANCE The complete equine aggrecan sequence will support more in-depth research on aggrecan processing and degradation in equine articular cartilage and other musculoskeletal tissues.
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Stanton H, Melrose J, Little CB, Fosang AJ. Proteoglycan degradation by the ADAMTS family of proteinases. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1616-29. [PMID: 21914474 DOI: 10.1016/j.bbadis.2011.08.009] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 08/20/2011] [Accepted: 08/23/2011] [Indexed: 10/17/2022]
Abstract
Proteoglycans are key components of extracellular matrices, providing structural support as well as influencing cellular behaviour in physiological and pathological processes. The diversity of proteoglycan function reported in the literature is equally matched by diversity in proteoglycan structure. Members of the ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) family of enzymes degrade proteoglycans and thereby have the potential to alter tissue architecture and regulate cellular function. In this review, we focus on ADAMTS enzymes that degrade the lectican and small leucine-rich repeat families of proteoglycans. We discuss the known ADAMTS cleavage sites and the consequences of cleavage at these sites. We illustrate our discussion with examples from the literature in which ADAMTS proteolysis of proteoglycans makes profound changes to tissue function.
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Affiliation(s)
- Heather Stanton
- University of Melbourne, Department of Paediatrics, Australia.
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Heinegård D. Fell-Muir Lecture: Proteoglycans and more--from molecules to biology. Int J Exp Pathol 2010; 90:575-86. [PMID: 19958398 DOI: 10.1111/j.1365-2613.2009.00695.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
In this article the organization and functional details of the extracellular matrix, with particular focus on cartilage, are described. All tissues contain a set of molecules that are arranged to contribute structural elements. Examples are fibril-forming collagens forming major fibrillar networks in most tissues. The assembly process is regulated by a number of proteins (thrombospondins, LRR-proteins, matrilins and other collagens) that can bind to the collagen molecule and in many cases remain bound to the formed fibre providing additional stability and enhancing networking to other structural networks. One such network is formed by collagen VI molecules assembled to beaded filaments in the matrix catalysed by interactions with small proteoglycans of the LRR-family, which remain bound to the filament providing for interactions via a linker of a matrilin to other matrix constituents like collagen fibres and the large proteoglycans, e.g. aggrecan in cartilage. Aggrecan is contributing an extreme anionic charge density to the extracellular matrix, which by osmotic effects leads to water retention and strive to swelling, resisted by the tensile properties of the collagen fibres. Aggrecan is bound via one end to hyaluronan, including such molecules retained at the cell surface, to form very large molecular entities that interact with other constituents of the matrix, e.g. fibulins that can form their own network. Other important interactions are those with cell surface receptors such as integrins, heparan sulphfate proteoglycans, hyaluronan receptors and others. Many of the molecules with an ability to interact with these receptors can also bind to molecules in the matrix and provide a bridge from the matrix to the cell and induce various responses. In pathology, there is an imbalance in matrix turnover with often excessive proteolytic breakdown. This results in the formation of protein fragments, where cleavage provides information on the active enzyme. Those fragments released can be specifically detected employing antibodies specific to the cleavage site and used to diagnose and monitor e.g. joint disease at early stages.
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Affiliation(s)
- Dick Heinegård
- Department of Clinical Sciences, Section for Rheumatology, Molecular Skeletal Biology, Lund University, Lund, Sweden.
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Fosang AJ, Last K, Poon CJ, Plaas AH. Keratan sulphate in the interglobular domain has a microstructure that is distinct from keratan sulphate elsewhere on pig aggrecan. Matrix Biol 2008; 28:53-61. [PMID: 19041721 DOI: 10.1016/j.matbio.2008.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 10/07/2008] [Accepted: 11/03/2008] [Indexed: 11/24/2022]
Abstract
The microstructure of keratan sulphate purified from the interglobular domain, the keratan sulphate-rich region and total aggrecan was compared using fluorophore-assisted-carbohydrate-electrophoresis. Keratan sulphate in the interglobular domain was substantially less sulphated than keratan sulphate elsewhere on aggrecan, based on the ratio of unsulphated: monosulphated disaccharides generated by endo-beta-galactosidase digestion, and the ratio of monosulphated: disulphated disaccharides generated by keratanase II digestion. The ratio of unsulphated: monosulphated: disulphated disaccharides was 1:4:5 for keratan sulphate from total aggrecan and the keratan sulphate-rich region, but only 1:0.9:0.8 for the interglobular domain. These results show that keratan sulphate in the interglobular domain of pig aggrecan has a microstructure that is distinct from keratan sulphate in the keratan sulphate-rich region.
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Affiliation(s)
- A J Fosang
- University of Melbourne Department of Paediatrics and Murdoch Children's Research Institute, Arthritis Research Group, Royal Children's Hospital, Parkville, 3052, Australia.
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Cavanagh JAL, Tammen I, Windsor PA, Bateman JF, Savarirayan R, Nicholas FW, Raadsma HW. Bulldog dwarfism in Dexter cattle is caused by mutations in ACAN. Mamm Genome 2007; 18:808-14. [PMID: 17952705 DOI: 10.1007/s00335-007-9066-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 08/13/2007] [Indexed: 11/27/2022]
Abstract
Bulldog dwarfism in Dexter cattle is one of the earliest single-locus disorders described in animals. Affected fetuses display extreme disproportionate dwarfism, reflecting abnormal cartilage development (chondrodysplasia). Typically, they die around the seventh month of gestation, precipitating a natural abortion. Heterozygotes show a milder form of dwarfism, most noticeably having shorter legs. Homozygosity mapping in candidate regions in a small Dexter pedigree suggested aggrecan (ACAN) as the most likely candidate gene. Mutation screening revealed a 4-bp insertion in exon 11 (2266_2267insGGCA) (called BD1 for diagnostic testing) and a second, rarer transition in exon 1 (-198C>T) (called BD2) that cosegregate with the disorder. In chondrocytes from cattle heterozygous for the insertion, mutant mRNA is subject to nonsense-mediated decay, showing only 8% of normal expression. Genotyping in Dexter families throughout the world shows a one-to-one correspondence between genotype and phenotype at this locus. The heterozygous and homozygous-affected Dexter cattle could prove invaluable as a model for human disorders caused by mutations in ACAN.
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Affiliation(s)
- Julie A L Cavanagh
- ReproGen, The University of Sydney, PMB3, Camden, New South Wales 2570, Australia.
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11
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Handley CJ, Samiric T, Ilic MZ. Structure, metabolism, and tissue roles of chondroitin sulfate proteoglycans. ADVANCES IN PHARMACOLOGY 2007; 53:219-32. [PMID: 17239768 DOI: 10.1016/s1054-3589(05)53010-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Affiliation(s)
- Christopher J Handley
- School of Human Biosciences, La Trobe University, Melbourne, Victoria 3086, Australia
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Struglics A, Larsson S, Lohmander LS. Estimation of the identity of proteolytic aggrecan fragments using PAGE migration and Western immunoblot. Osteoarthritis Cartilage 2006; 14:898-905. [PMID: 16635583 DOI: 10.1016/j.joca.2006.02.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2005] [Accepted: 02/28/2006] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To develop calculation models, using Western immunoblot, as a tool for the estimation of proteolytic human aggrecan fragment identity. METHOD Seven human aggrecan fragments (calibrators), purified by CsCl gradient centrifugation and identified by Western immunoblot of N- and C-terminals, were used to develop calculation models. The models were used for identification of unknown aggrecan fragments each having one of their N- or C-terminals identified. RESULTS The calibrator molecular weights (Mw) from sodium dodecyl sulfate (SDS)-gels (m), the Mw of amino acids (a) and the Mw of their carbohydrate substitution (g) were expressed as K = m/(a+g), or as K = 1.085m/(a+g) when compensation for the G1 domain was required. Using these models together with average K-values, 12 out of the 17 immuno-detected aggrecan fragments were calculated to a known protease cleavage site, while five were identified to domain levels. CONCLUSIONS With six neoepitope antibodies together with antibodies against the G1- and G3-domain it was possible to predict the identity of several proteolytic fragments from different regions within the aggrecan monomer.
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Affiliation(s)
- A Struglics
- Department of Clinical Sciences, Orthopaedics, Lund University, Lund, Sweden.
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13
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Cavanagh JAL, Tammen I, Hayden MJ, Gill CA, Nicholas FW, Raadsma HW. Characterization of the bovine aggrecan gene: genomic structure and physical and linkage mapping. Anim Genet 2006; 36:452-4. [PMID: 16167996 DOI: 10.1111/j.1365-2052.2005.01340.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- J A L Cavanagh
- Centre for Advanced Technologies in Animal Genetics and Reproduction (Reprogen), Faculty of Veterinary Science, The University of Sydney, Camden NSW 2570, Australia.
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Kiani C, Chen L, Lee V, Zheng PS, Wu Y, Wen J, Cao L, Adams ME, Sheng W, Yang BB. Identification of the motifs and amino acids in aggrecan G1 and G2 domains involved in product secretion. Biochemistry 2003; 42:7226-37. [PMID: 12795619 DOI: 10.1021/bi027241z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Members of the large aggregating chondroitin sulfate proteoglycans are characterized by an N-terminal fragment known as G1 domain, which is composed of an immunoglobulin (IgG)-like motif and two tandem repeats (TR). Previous studies have indicated that the expressed product of aggrecan G1 domain was not secreted. Here we demonstrated that the inability of G1 secretion was associated with the tandem repeats but not the IgG-like motif, and specifically with TR1 of aggrecan. We also demonstrated that the G2 domain, a domain unique to aggrecan, had a similar effect on product secretion. The sequence of TR1 of G1 is highly conserved across species, which suggested similar functions played by these motifs. In a yeast two-hybrid assay, TR1 interacted with the calcium homeostasis endoplasmic reticulum protein. Deletion/mutation experiments indicated that the N-terminal fragment of TR1, in particular, the amino acids H(2)R(4) of this motif were key to its effect on product secretion. However, the N-terminal 55 amino acids were required to exert this function. Taken together, our study suggests a possible molecular mechanism for the function of the tandem repeats in product processing.
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Affiliation(s)
- Chris Kiani
- Sunnybrook & Women's College Health Sciences Centre and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
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15
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Abstract
Aggrecan is the major proteoglycan in the articular cartilage. This molecule is important in the proper functioning of articular cartilage because it provides a hydrated gel structure (via its interaction with hyaluronan and link protein) that endows the cartilage with load-bearing properties. It is also crucial in chondroskeletal morphogenesis during development. Aggrecan is a multimodular molecule expressed by chondrocytes. Its core protein is composed of three globular domains (G1, G2, and G3) and a large extended region (CS) between G2 and G3 for glycosaminoglycan chain attachment. G1 comprises the amino terminus of the core protein. This domain has the same structural motif as link protein. Functionally, the G1 domain interacts with hyaluronan acid and link protein, forming stable ternary complexes in the extracellular matrix. G2 is homologous to the tandem repeats of G1 and of link protein and is involved in product processing. G3 makes up the carboxyl terminus of the core protein. It enhances glycosaminoglycan modification and product secretion. Aggrecan plays an important role in mediating chondrocyte-chondrocyte and chondrocyte-matrix interactions through its ability to bind hyaluronan.
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Affiliation(s)
- Chris Kiani
- Sunnybrook and Women's College Health Sciences Centre, Faculty of Medicine, University of Toronto, Canada
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16
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Hunter CJ, Imler SM, Malaviya P, Nerem RM, Levenston ME. Mechanical compression alters gene expression and extracellular matrix synthesis by chondrocytes cultured in collagen I gels. Biomaterials 2002; 23:1249-59. [PMID: 11791929 DOI: 10.1016/s0142-9612(01)00245-9] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Articular cartilage responds to its mechanical environment through altered cell metabolism and matrix synthesis. In this study, isolated articular chondrocytes were cultured in collagen type I gels and exposed to uniaxial static compression of 0%, 25%, or 50% of original thickness for 0.5, 4, and 24 h, and to oscillatory (25 +/- 4%, 1 Hz) compression for 24 h. The cellular response was assessed through competitive and real-time RT-PCR to quantify expression of genes for collagen type I, collagen type II, and aggrecan core protein, and through radiolabelled proline and sulfate incorporation to quantify protein and proteoglycan synthesis rates. Static compression for 24 h inhibited expression of collagen I and II mRNAs and inhibited 3H-proline and 35S-sulfate incorporation. The mRNA expression exhibited transient fluctuations at intermediate time points. Oscillatory compression had no effect upon mRNA expression, and 24 h after release from static compression, there was no difference in collagen II or aggrecan mRNA, while there was an inhibition of collagen I. We conclude that the chondrocytes maintained some aspects of their ability to sense and respond to static compression, despite a biochemical and mechanical environment which is different from that in tissue. This suggests that mechanical stimuli may be useful in modulating chondrocyte metabolism in tissue engineering systems using fibrillar protein scaffolds.
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Affiliation(s)
- Christopher J Hunter
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta 30332-0535, USA
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17
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Abstract
The in vivo role of the extracellular matrix and the manner in which it interfaces with soluble regulators remains largely unknown. The current study reports the extracellular Type II collagen modulation of transforming growth factor-beta 1-stimulated proliferation, proteoglycan synthesis, messenger ribonucleic acid expression for transforming growth factor-beta 1, and integrin messenger ribonucleic acid expression in articular chondrocytes from adults. This study shows that this cytokine modulation occurs through a mechanism initiated by the attachment of Type II collagen to the beta1-integrin. Transforming growth factor-beta 1 stimulated deoxyribonucleic acid and proteoglycan synthesis in a bimodal fashion. Extracellular Type II collagen increased transforming growth factor-beta 1-stimulated deoxyribonucleic acid and proteoglycan synthesis, aggrecan gene expression as much as 400%, and alpha1(II) procollagen gene expression as much as 180% in a dose-dependent fashion. Heat inactivation of the Type II collagen abrogated the observed effects on deoxyribonucleic acid and proteoglycan synthesis. In contrast to Type II collagen, heat-denatured collagen and bovine serum albumin showed none of the observed effects. The presence of Type II collagen in the alginate bead cultures was found to diminish the messenger ribonucleic acid expression for alpha2 integrin and alter the cellular distribution pattern of the beta1 integrin receptors. Blocking of the beta1-integrin with cyclic-peptides containing the Arg-Gly-Asp sequences and antibodies reduced chondrocyte attachment to Type II collagen by 93%. The physiologic effects shown by the chondrocyte as a result of blocking this attachment to Type II collagen were a significant reduction in transforming growth factor-beta 1-stimulated deoxyribonucleic acid and proteoglycan synthesis. The conclusions elucidate the role played by the extracellular matrix in cytokine-specific regulation of the articular chondrocyte. The authors have shown that extracellular Type II collagen acts through a beta1-integrin mediated mechanism to modulate the chondrocyte response to transforming growth factor-beta 1.
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Affiliation(s)
- S P Scully
- Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
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18
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Schwartz NB, Pirok EW, Mensch JR, Domowicz MS. Domain organization, genomic structure, evolution, and regulation of expression of the aggrecan gene family. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2001; 62:177-225. [PMID: 9932455 DOI: 10.1016/s0079-6603(08)60508-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Proteoglycans are complex macromolecules, consisting of a polypeptide backbone to which are covalently attached one or more glycosaminoglycan chains. Molecular cloning has allowed identification of the genes encoding the core proteins of various proteoglycans, leading to a better understanding of the diversity of proteoglycan structure and function, as well as to the evolution of a classification of proteoglycans on the basis of emerging gene families that encode the different core proteins. One such family includes several proteoglycans that have been grouped with aggrecan, the large aggregating chondroitin sulfate proteoglycan of cartilage, based on a high number of sequence similarities within the N- and C-terminal domains. Thus far these proteoglycans include versican, neurocan, and brevican. It is now apparent that these proteins, as a group, are truly a gene family with shared structural motifs on the protein and nucleotide (mRNA) levels, and with nearly identical genomic organizations. Clearly a common ancestral origin is indicated for the members of the aggrecan family of proteoglycans. However, differing patterns of amplification and divergence have also occurred within certain exons across species and family members, leading to the class-characteristic protein motifs in the central carbohydrate-rich region exclusively. Thus the overall domain organization strongly suggests that sequence conservation in the terminal globular domains underlies common functions, whereas differences in the central portions of the genes account for functional specialization among the members of this gene family.
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Affiliation(s)
- N B Schwartz
- Department of Pediatrics, University of Chicago, Illinois 60637, USA
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19
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Covizi DZ, Carvalho HF. Aggrecan structure in amphibian cartilage. Braz J Med Biol Res 2000; 33:1403-12. [PMID: 11105091 DOI: 10.1590/s0100-879x2000001200002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The structure of the large proteoglycan present in the bullfrog epiphyseal cartilage was studied by immunochemical and biochemical methods. The isolated monomer showed a polydisperse behavior on Sepharose CL2B, with a peak at Kav = 0.14. Chondroitin sulfate chains were identified by HPLC analysis of the products formed by chondroitinase digestion and mercuric acetate treatment. These chains have approximately 38 disaccharides, a Di45:Di68 ratio of 1.6 and GalNAc4S + GalNAc4,6S are the main non-reducing terminals. Keratan sulfate was identified by the use of two monoclonal antibodies in Western blots after chondroitinase ABC treatment. A keratan sulfate-rich region (approximately 110 kDa) was isolated by sequential treatment with chondroitinase ABC and proteases. We also employed antibodies in Western blotting experiments and showed that the full length deglycosylated core protein is about 300 kDa after SDS-PAGE. Domain-specific antibodies revealed the presence of immunoreactive sites corresponding to G1/G2 and G3 globular domains and the characterization of this large proteoglycan as aggrecan. The results indicate the high conservation of the aggrecan domain structure in this lower vertebrate.
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Affiliation(s)
- D Z Covizi
- Departamento de Biologia Celular, Universidade Estadual de Campinas, Campinas, SP, Brasil
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20
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Sandy JD, Thompson V, Verscharen C, Gamett D. Chondrocyte-mediated catabolism of aggrecan: evidence for a glycosylphosphatidylinositol-linked protein in the aggrecanase response to interleukin-1 or retinoic acid. Arch Biochem Biophys 1999; 367:258-64. [PMID: 10395742 DOI: 10.1006/abbi.1999.1234] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The control of chondrocyte-mediated degradation of aggrecan has been studied in rat chondrosarcoma cells and bovine cartilage explants treated with either IL-1 or retinoic acid. The capacity of glucosamine to inhibit the aggrecanase-mediated response (J. D. Sandy, D. Gamett, V. Thompson, and C. Verscharen (1998) Biochem. J. 335, 59-66) has been extended to an investigation of the effect of other hexosamines. Mannosamine inhibits the aggrecanase response to both IL-1 and RA at about one-tenth the concentration of glucosamine in both rat cell and bovine explant systems. This effect of mannosamine appears to be due to its capacity to inhibit the synthesis of glycosylphosphatidylinositol (GPI)-linked proteins by chondrocytes since the GPI synthesis inhibitor 2-deoxyfluoroglucose (2-DFG) also inhibited the aggrecanase response to IL-1b and RA in rat cells. Moreover, phosphatidylinositol-specific phospholipase C (PIPLC) treatment of rat cells markedly inhibited the aggrecanase response to IL-1b and RA. These inhibitory effects of mannosamine, 2-DFG, and PIPLC in rat cells did not appear to be due to an interference with general biosynthetic activity of the cells as measured by [3H]proline incorporation into secreted proteins. We suggest that the aggrecanase response by chondrocytes to IL-1 and RA is dependent on the activity of a GPI-anchored protein on the chondrocyte cell surface.
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Affiliation(s)
- J D Sandy
- Biochemistry Section, Shriners Hospital, Tampa Unit, 12502 North Pine Drive, Tampa, Florida, 33612, USA.
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21
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Hedlund H, Hedbom E, Heineg rd D, Mengarelli-Widholm S, Reinholt FP, Svensson O. Association of the aggrecan keratan sulfate-rich region with collagen in bovine articular cartilage. J Biol Chem 1999; 274:5777-81. [PMID: 10026199 DOI: 10.1074/jbc.274.9.5777] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aggrecan, the predominant large proteoglycan of cartilage, is a multidomain macromolecule with each domain contributing specific functional properties. One of the domains contains the majority of the keratan sulfate (KS) chain substituents and a protein segment with a proline-rich hexapeptide repeat sequence. The function of this domain is unknown but the primary structure suggests a potential for binding to collagen fibrils. We have examined binding of aggrecan fragments encompassing the KS-rich region in a solid-phase assay. A moderate affinity (apparent Kd = 1.1 microM) for isolated collagen II, as well as collagen I, was demonstrated. Enzymatic digestion of the KS chains did not alter the capacity of the peptide to bind to collagen, whereas cleavage of the protein core abolished the interaction. The distribution of the aggrecan KS-rich region in bovine tarsometatarsal joint cartilage was investigated using immunoelectron microscopy. Immunoreactivity was relatively low in the superficial zone and higher in the intermediate and deep zones of the uncalcified cartilage. Within the pericellular and territorial matrix compartments the epitopes representing the aggrecan KS-rich region were detected preferentially near or at collagen fibrils. Along the fibrils, epitope reactivity was non-randomly distributed, showing preference for the gap region within the D-period. Our data suggest that collagen fibrils interact with the KS-rich regions of several aggrecan monomers aligned within a proteoglycan aggregate. The fibril could therefore serve as a backbone in at least some of the aggrecan complexes.
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Affiliation(s)
- H Hedlund
- Department of Orthopedics, Karolinska Institutet, Huddinge University Hospital, SE-141 86 Huddinge, Sweden.
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22
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Ilic MZ, Robinson HC, Handley CJ. Characterization of aggrecan retained and lost from the extracellular matrix of articular cartilage. Involvement of carboxyl-terminal processing in the catabolism of aggrecan. J Biol Chem 1998; 273:17451-8. [PMID: 9651333 DOI: 10.1074/jbc.273.28.17451] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The catabolism of aggrecan in bovine articular cartilage explants is characterized by the release into the culture medium of high molecular weight aggrecan fragments, generated by the proteolytic cleavage of the core protein between residues Glu373 and Ala374 within the interglobular domain. In this study, the position of the carboxyl-terminus of these aggrecan fragments, as well as a major proteolytically shortened aggrecan core protein present in cartilage matrix, have been deduced by characterizing the peptides generated by the reaction of aggrecan core protein peptides with cyanogen bromide. It was shown that two out of three such peptide fragments having an amino terminus starting at Ala374 have their carboxyl terminus located within the chondroitin sulfate 1 domain. The third and largest aggrecan core protein peptide, with an amino terminus starting at Ala374, has a carboxyl terminus in a region of core protein between the chondroitin sulfate 1 domain and the chondroitin sulfate 2 domain. The carboxyl terminus of this peptide appeared to be the same as that of the proteolytically degraded aggrecan core protein, which is retained within the extracellular matrix of the tissue. Another two aggrecan fragments recovered from the medium of explant cultures with amino-terminal sequences in the chondroitin sulfate 2 domain at Ala1772 and Leu1872 were shown to have their carboxyl termini within the G3 globular domain. These results suggest that the catabolism of aggrecan between residues Glu373 and Ala374 in the interglobular domain by the putative proteinase, aggrecanase, may be dependent on prior proteolytic processing within the carboxyl-terminal region of the core protein.
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Affiliation(s)
- M Z Ilic
- School of Human Biosciences, La Trobe University, Bundoora 3083, Victoria, Australia
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23
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Abstract
The in vivo role of the extracellular matrix and the manner in which it interfaces with soluble regulators remains unknown. This study reports the modulation by extracellular type II collagen of TGF-beta 1-stimulated DNA synthesis, proteoglycan synthesis, and mRNA expression for alpha 1(II) procollagen and aggrecan core protein in the adult articular chondrocyte. Bovine chondrocytes were isolated and resuspended in alginate beads which contained increasing amounts of type II collagen from 0 to 1.5% (w/v). Cultures were maintained for 7 days in basal, DMEM, TGF-beta 1 (10 ng/ml), or FBS (10%) supplemented medium. DNA and proteoglycan synthesis were determined by radiotracer incorporation. The relative amounts of mRNA were analyzed by Northern blot analysis. Exogenous collagen increased DNA synthesis in all culture conditions beginning at concentrations of 0.75% (w/v). We observed that extracellular type II collagen augments both TGF-beta 1 stimulated increases of aggrecan gene expression up to 400% and alpha 1(II) procollagen gene expression up to 180% in a dose-dependent fashion. This is distinct from cultures which were either basal or FBS supplemented medium which lacked a dose-dependent change in aggrecan gene expression and demonstrated a decrease in alpha 1(II) procollagen gene expression. Exogenous collagen above 0.75% (w/v) increased proteoglycan synthesis significantly in FBS and TGF-beta 1-stimulated cultures but not in basal cultures. We have demonstrated that the alterations in gene expression that occur in response to TGF-beta 1 are modulated by extracellular type II collagen. This modulation is possible through both transcriptional and posttranscriptional regulatory mechanisms.
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Affiliation(s)
- W N Qi
- Division of Orthopaedics, Duke University Medical Center, Durham, North Carolina 27710, USA
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24
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Hering TM, Kollar J, Huynh TD. Complete coding sequence of bovine aggrecan: comparative structural analysis. Arch Biochem Biophys 1997; 345:259-70. [PMID: 9308898 DOI: 10.1006/abbi.1997.0261] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The previously available sequence for bovine aggrecan included only the KS domain, the C-terminal portion of the CS-2 domain, and the entire CS-3 and G3 domains. We have isolated cDNA clones for previously uncharacterized portions of the bovine aggrecan sequence, and, when we combined them with previously published incomplete sequences, have obtained a complete sequence for the entire core protein. The bovine aggrecan sequence, which is a composite of new sequence data and previously published incomplete sequences, is 2327 residues in length. Although there is significant conservation of G1, G2, and G3 globular domains between species, there are differences in the length of the interglobular domain, in the number of KS domain hexapeptide repeats and CS domain repeats, and in alternative splicing within the G3 domain. The bovine aggrecan KS domain contains 24 repeats of a hexapeptide motif. The largely uncharacterized CS-1 domain of bovine aggrecan was found to contain 27 variable repeats of a 21-residue consensus sequence. A notable feature of the bovine CS-1 domain is in the distribution of single Ser-Gly dipeptides, the majority of which are separated by 7 or 8 amino acids, compared to the human, where discrete pairs of Ser-Gly dipeptides are separated by 13 amino acids. The CS-2 domain contains a total of six "homology domains" with 4 complete and 2 partial approximately 100-residue repeats. Each "homology domain" contains a "nodal" region with few sites for CS chain addition that is highly conserved between species, suggesting a possible role in aggrecan biosynthesis or catabolism.
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Affiliation(s)
- T M Hering
- Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4946, USA.
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25
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Doege KJ, Coulter SN, Meek LM, Maslen K, Wood JG. A human-specific polymorphism in the coding region of the aggrecan gene. Variable number of tandem repeats produce a range of core protein sizes in the general population. J Biol Chem 1997; 272:13974-9. [PMID: 9153261 DOI: 10.1074/jbc.272.21.13974] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Aggrecan, one of the major structural genes of cartilage, encodes a proteoglycan core protein composed of an extended central glycosaminoglycan-bearing domain, flanked by globular domains at each end. The central region consists of long stretches of repeating amino acids that serve as attachment sites for glycosaminoglycans such as chondroitin and keratan sulfate; the terminal globular domains interact with other cartilage components. The glycosaminoglycan attachment region is encoded in several species by a single large exon, within which are several different types of repeating sequences. Several species show within this exon a similar block of conserved repeats for attachment of chondroitin sulfate, but in humans this group of repeats is particularly well conserved. Examination of genomic DNA from a population of unrelated individuals by polymerase chain reaction or Southern blot assays shows this block of repeat sequences exists in multiple allelic forms, which differ by the number of repeats at this site in each allele. Thirteen different alleles have been identified, with repeat numbers ranging from 13 to 33. This is an unusual example of an expressed variable number of tandem repeat polymorphism. This polymorphism is apparently restricted to humans, of several species examined. This polymorphism results in individuals with differing length aggrecan core proteins, bearing different numbers of potential attachment sites for chondroitin sulfate. The possibility exists for a molecular understanding of biological variation in cartilage functional properties.
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Affiliation(s)
- K J Doege
- Shriners Hospital for Children, Portland, Oregon 97210, USA.
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26
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Hauser N, Paulsson M, Heinegârd D, Mörgelin M. Interaction of cartilage matrix protein with aggrecan. Increased covalent cross-linking with tissue maturation. J Biol Chem 1996; 271:32247-52. [PMID: 8943283 DOI: 10.1074/jbc.271.50.32247] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Cartilage matrix protein (CMP) is a trimeric protein present in many types of cartilage extracellular matrix. It has recently been purified under native conditions that allowed the proposal of a structural model (Hauser, N., and Paulsson, M. (1994) J. Biol. Chem. 269, 25747-25753). To examine the functional properties of CMP we studied its interaction with aggrecan within cartilage extracellular matrix. Aggrecan-enriched fractions were purified from bovine tracheal cartilage of different ages under nondenaturing and denaturing conditions, respectively, and characterized by a combination of biochemical methods and electron microscopy. The fractions contained a pool of CMP noncovalently associated with aggrecan as well as a pool of CMP that appears covalently cross-linked to the aggrecan core protein. Only about two thirds of the CMP subunits could be released even upon reduction under denaturing conditions. It appears that CMP is attached by a nonreducible covalent interaction of one of its subunits with the protein core. The amount of CMP strongly bound to aggrecan increases with age. Electron microscopy revealed interaction sites for CMP in the extended chondroitin-sulfate attachment domain E2. In old tissue five distinct binding sites for CMP were found while in young cartilage only three of these were occupied. The extent of decoration of E2 with CMP increases with age.
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Affiliation(s)
- N Hauser
- Institute for Biochemistry, Medical Faculty, University of Cologne, D-50931 Cologne, Germany
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27
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Fernàndez-Busquets X, Kammerer RA, Burger MM. A 35-kDa protein is the basic unit of the core from the 2 x 10(4)-kDa aggregation factor responsible for species-specific cell adhesion in the marine sponge Microciona prolifera. J Biol Chem 1996; 271:23558-65. [PMID: 8798565 DOI: 10.1074/jbc.271.38.23558] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Dissociated sponge cells quickly reaggregate in a species-specific manner, differentiate, and reconstruct tissue, providing a very handy system to investigate the molecular basis of more complex intercellular recognition processes. Species-specific cell adhesion in the marine sponge Microciona prolifera is mediated by a supramolecular complex with a Mr = 2 x 10(7), termed aggregation factor. Guanidinium hydrochloride/cesium chloride dissociative gradients and rhodamine B isothiocyanate staining indicated the presence of several proteins with different degrees of glycosylation. Hyaluronate has been found to be associated with the aggregation factor. Chemical deglycosylation revealed a main component accounting for nearly 90% of the total protein. The cDNA-deduced amino acid sequence predicts a 35-kDa protein (MAFp3), the first sponge aggregation factor core protein ever described. The open reading frame is uninterrupted upstream from the amino terminus of the mature protein, and the deduced amino acid sequence for this region has been found to contain a long stretch sharing homology with the Na+-Ca2+ exchanger protein. A putative hyaluronic acid binding domain and several putative N- and O-glycosylation signals are present in MAFp3, as well as eight cysteines, some of them involved in intermolecular disulfide bridges. Northern blot data suggest variable expression, and Southern blot analysis reveals the presence of other related gene sequences. According to the respective molecular masses, one aggregation factor molecule would contain about 300 MAFp3 units, suggesting that sponge cell adhesion might be based on the assembly of multiple small glycosylated protein subunits.
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28
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Takahashi K, Stamenkovic I, Cutler M, Dasgupta A, Tanabe KK. Keratan sulfate modification of CD44 modulates adhesion to hyaluronate. J Biol Chem 1996; 271:9490-6. [PMID: 8621620 DOI: 10.1074/jbc.271.16.9490] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
CD44 alternative splicing has been implicated in the regulation of CD44 function. CD44 undergoes significant posttranslational modification in all cells, but the functional consequences of these modifications are poorly understood. In the current study, we have demonstrated that keratan sulfate modification of CD44 significantly modulates its ability to bind to hyaluronate. We observed naturally occurring differences in CD44 keratan sulfate substitution between two clonal variants of the KM12 human colon carcinoma cell line. CD44 on the highly metastatic KM12L4 clone is more heavily substituted with keratan sulfate than CD44 on the poorly metastatic KM12C6 clone. Moreover, CD44H on KM12L4 bound to hyaluronate poorly compared to CD44H on KM12C6. Removal of keratan sulfate from CD44 greatly enhanced CD44-mediated cell adhesion to hyaluronate. Removal of keratan sulfate from CD44H-immunoglobulin fusion proteins also enhanced their adhesion to hyaluronate. The influence of glycosaminoglycan substitution on CD44 function was specific to keratan sulfate substitution; treatment to remove chondroitin sulfate, heparan sulfate, or hyaluronate did not affect CD44-mediated cell adhesion to hyaluronate. Use of site-directed CD44H cDNA mutants with arginine changed to alanine at position 41 indicated that keratan sulfate modification of CD44 modulates hyaluronate adhesion through its B loop domain. These findings suggest that keratan sulfate modification of CD44 may play an important regulatory role in the broad spectrum of biological processes attributed to CD44, including normal development, tumor progression, and lymphocyte function.
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Affiliation(s)
- K Takahashi
- Division of Surgical Oncology, Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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29
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Bengtsson E, Neame PJ, Heinegård D, Sommarin Y. The primary structure of a basic leucine-rich repeat protein, PRELP, found in connective tissues. J Biol Chem 1995; 270:25639-44. [PMID: 7592739 DOI: 10.1074/jbc.270.43.25639] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We have determined the primary structure of a connective tissue matrix protein from the nucleotide sequence of a clone isolated from a human articular chondrocyte cDNA library. The major part of the amino acid sequence has also been determined by direct protein sequencing. The translated primary sequence corresponds to 382 amino acid residues, including a 20-residue signal peptide. The molecular mass of the mature protein is 41,646 Da. The main part of the protein consists of 10 leucine-rich repeats ranging in length from 20 to 26 residues, with asparagine at position 10 (B-type). The N-terminal part is unusual in that it is basic and rich in arginine and proline. There are four potential N-linked glycosylation sites present. In three of these sites, post-translational modifications are likely to be present since Asn was not found by direct protein sequencing. The amino- and carboxyl-terminal parts contain four and two cysteine residues, respectively, probably forming disulfide bonds by analogy with the other members of this family. The protein shows highest identity (36%) to fibromodulin and 33% to bovine lumican, two other leucine-rich repeat connective tissue proteins. Northern blot analysis showed the presence of an approximately 3.8-kilobase mRNA in different types of bovine cartilage and cultured osteoblasts, whereas RNAs isolated from bovine kidney, skin, spleen, thymus, and trabecular bone and rat calvaria were negative. Human articular chondrocyte and rat chondrosarcoma cell RNAs contained an additional mRNA of approximately 1.6 and 1.8 kilobases, respectively.
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Affiliation(s)
- E Bengtsson
- Department of Cellular and Molecular Biology, Lund University, Sweden
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Barry FP, Rosenberg LC, Gaw JU, Gaw JU, Koob TJ, Neame PJ. N- and O-linked keratan sulfate on the hyaluronan binding region of aggrecan from mature and immature bovine cartilage. J Biol Chem 1995; 270:20516-24. [PMID: 7657627 DOI: 10.1074/jbc.270.35.20516] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In the hyaluronan binding region (HABR) peptide of aggrecan, there is a marked increase in the level of keratan sulfate (KS) during aging. To determine the sites of KS attachment, KS-containing peptides were prepared from HABRs from immature and mature bovine articular cartilage by digestion with trypsin or papain followed by carbohydrate analysis and peptide sequencing. KS is attached to Thr42 within loop A in mature, but not in immature, HABR. Within loop B KS is N-linked to Asn220 in both HABRs, but in the immature HABR the chains are shorter. Asn314 in loop B' of mature HABR is substituted either with a KS chain or with an oligosaccharide of the complex type. In immature HABR this site does not carry KS. In the interglobular domain, 2 threonine residues within the sequence TIQTVT are substituted in both calf and steer, and in steer further substitution occurs within the sequence NITEGEA, which contains a major catabolic cleavage site (Sandy, J., Neame, P.J., Boynton, R., and Flannery, C.R. (1991) J. Biol. Chem. 266, 8683-8685). The extreme polydispersity of mature HABR was investigated by preparing four subfractions of increasing molecular size which had essentially the same protein core, i.e. Val1-Arg367 or Val1-Arg375. The smaller species lacked the KS chains attached to loop A. These results show that KS substitution occurs within each of the disulfide-bonded loops of the HABR, that the KS may be either N- or O-linked, and that variations in the addition of KS are responsible for the polydispersity of mature HABR.
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Affiliation(s)
- F P Barry
- Shriners Hospital for Crippled Children, University of South Florida College of Medicine, Tampa 33612, USA
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Bonassar LJ, Frank EH, Murray JC, Paguio CG, Moore VL, Lark MW, Sandy JD, Wu JJ, Eyre DR, Grodzinsky AJ. Changes in cartilage composition and physical properties due to stromelysin degradation. ARTHRITIS AND RHEUMATISM 1995; 38:173-83. [PMID: 7848307 DOI: 10.1002/art.1780380205] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To determine the effects of stromelysin treatment on biochemical, histologic, and swelling characteristics of intact cartilage explants and to correlate these effects with changes in the functional physical properties of the tissue. METHODS Bovine articular cartilage explants were cultured for up to 3 days in the presence or absence of recombinant human stromelysin (SLN). Damage to matrix proteoglycans and collagens was assessed and characterized by N-terminal sequencing and Western blot analysis, respectively. Explants were mechanically tested to assess the ability of the tissue to withstand cyclic and static compressive loads. RESULTS Treatment with SLN resulted in a time- and dose-dependent loss of proteoglycans from cartilage explants, with significant loss seen after 3 days of exposure to 20 nM SLN: Histology indicated that initial loss of proteoglycans occurred in regions near the tissue surface and proceeded inward with increasing time of SLN exposure. SLN treatment resulted in degradation of matrix collagen types IX and II, and a concomitant increase in tissue swelling. This matrix degradation resulted in severe alterations in functional physical properties of the tissue, including compressive stiffness. The initial, focal loss of proteoglycans that resulted from SLN treatment was most accurately detected with high-frequency streaming potential measurements. CONCLUSION Exposure of intact cartilage to SLN caused specific, molecular-level degradation of matrix molecules, which resulted in changes in the swelling behavior and marked deterioration of functional physical properties of the tissue.
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Affiliation(s)
- L J Bonassar
- Massachusetts Institute of Technology, Cambridge 02139
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Brown GM, Huckerby TN, Nieduszynski IA. Oligosaccharides derived by keratanase II digestion of bovine articular cartilage keratan sulphates. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 224:281-308. [PMID: 7925342 DOI: 10.1111/j.1432-1033.1994.00281.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Alkaline borohydride-reduced keratan sulphate chains from bovine articular cartilage (6-8-year-old animals) were subjected to a limit digest with the enzyme keratanase II. Using 1H-NMR spectroscopy, 25 reduced oligosaccharides deriving from keratan sulphate were shown to have the following structures [GlcNAc(6S)-ol represents N-acetylglucosaminitol 6-O-sulphate]: Gal beta 1-4-GlcNAc(6S)-ol, Gal beta 1-4GlcNAc(6S)beta 1-3Gal beta 1-4GlcNAc(6S)-ol, Gal(6S)beta 1-4GlcNAc(6S)-ol, Gal-(6S)beta 1-4GlcNAc(6S) beta 1-3Gal beta 1-4GlcNAc(6S)-ol, Gal beta 1-4GlcNAc(6S)beta 1-3Gal(6S)beta 1-4GlcNAc(6S)-ol, Gal(6S)beta 1-4GlcNAc(6S)beta 1-3Gal(6S)1-4GlcNAc(6S)-ol, Gal beta 1-4(Fuc alpha 1-3)GlcNAc(6S)-ol, Gal beta 1-4-(Fuc alpha 1-3)GlcNAc(6S)beta1-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc(6S)-ol, Gal beta 1-4GlcNAc(6S)beta 1-3Gal beta 1-4(Fuc alpha 1-3)-GlcNAc(6S)-ol, Gal beta 1-4(Fuc alpha 1-3)GlcNAc(6S)beta 1-3Gal beta 1-4GlcNAc(6S)-ol, Gal(6S) beta 1-4GlcNAc-(6S)beta 1-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc(6S)-ol, Gal beta 1-4(Fuc alpha 1-3)GlcNAc(6S)beta 1-3Gal(6S)1-4GlcNAc(6S)-ol, Gal beta 1-4GlcNAc(6S)beta 1-6(Gal beta 1-3)GalNAc-ol, Gal beta 1-4GlcNAc(6S) beta1-6(NeuAc2-3Gal beta 1-3)Gal-NAc-ol, Gal beta 1-4GlcNAc(6S)beta 1-3Gal beta 1-4GlcNAc(6S)beta 1-6(Gal beta 1-3) GalNAc-ol, Gal(6S)beta 1-4GlcNAc-(6S)beta 1-6(Gal beta 1-3)GalNAc-ol, Gal beta 1-4GlcNAc(6S)beta 1-3Gal beta 1-4GlcNAc(6S)beta 1-6(NeuAc2-3Gal beta 1-3)-GalNAc-ol, Gal(6S)beta 1-4GlcNAc(6S)beta 1-6(NeuAc alpha 2-3Gal beta 1-3)GalNAc-ol, Gal(6S) beta 1-4GlcNAc-(6S)beta 1-3Gal beta 1-4GlcNAc(6S)beta 1-6(Gal beta 1-3)GalNAc- ol, Gal(6S)beta 1-4GlcNAc(6S)beta 1-3Gal beta 1-4GlcNAc-(6S)beta 1-6(NeuAc alpha 2-3Gal beta 1-3)GalNAc-ol, NeuAc alpha 2-6Gal beta 1-4GlcNAc(6S)beta 1-3Gal beta 1-4GlcNAc(6S)-ol, NeuAc alpha 2-3Gal beta 1-4GlcNAc(6S)beta 1-3Gal beta 1-4GlcNAc(6S)-ol, NeuAc alpha 2-6Gal beta 1-4GlcNAc(6S)beta 1-3Gal-(6S)beta 1-4GlcNAc(6S)-ol, NeuAc alpha 2-3Gal beta 1-4GlcNAc(6S)beta 1-3Gal(6S)beta 1-4GlcNAc(6S)-ol and Neu-Ac alpha 2-3Gal(6S)beta 1-4GlcNAc(6S)beta 1-3Gal(6S beta)1-4GlcNAc(6S)-ol. Proton chemical shifts for these oligosaccharides were assigned using one- and two-dimensional NMR spectroscopic methods. These results confirm the findings of Nakazawa et al. [Nakazawa, K., Ito, M., Yamagata, T. and Suzuki, S. (1989) in Keratan sulphate: chemistry, biology and chemical pathology (Greiling, H. and Scott, J.E., eds) pp. 99-110, The Biochemical Society, London], namely that keratanase II cleaves the O-glycosidic bond of a beta(1-3)-linked 6-O-sulphated N-acetylglucosamine.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- G M Brown
- Division of Biological Sciences, University of Lancaster, England
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Barry FP, Neame PJ, Sasse J, Pearson D. Length variation in the keratan sulfate domain of mammalian aggrecan. Matrix Biol 1994; 14:323-8. [PMID: 7827755 DOI: 10.1016/0945-053x(94)90198-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The keratan sulfate domain of aggrecan consists of a series of tandemly repeating hexapeptides which have the consensus sequence Glu-Glu/Lys-Pro-Phe-Pro-Ser, where the serine side-chains presumably provide sites for the attachment of keratan sulfate (KS) chains. The number of hexapeptide repeats varies between species, ranging from four in rat (Doege et al., 1987) and mouse (Walcz et al., 1992) to 13 in human (Doege et al., 1991) and 23 in bovine aggrecan (Antonsson et al., 1989). Chicken aggrecan (Chandrasekaran and Tanzer, 1992) does not contain a KS domain with a recognizable hexapeptide motif. The extent of this variation among mammalian and avian species is not known, and there is currently no explanation to predict how differences in the size of the KS domain would affect aggrecan function. We used polymerase chain reaction (PCR) to amplify the portion of the human, canine and porcine aggrecan gene that codes for the KS domain. We sequenced the amplified products in each case. Human aggrecan, with 13 hexapeptide repeats (Doege et al., 1987), was used as reference and found to be essentially identical to published data. The canine and porcine KS domains consisted of six and ten hexapeptide repeats respectively. The same PCR protocol was used to amplify the KS domain from genomic DNA of eight other mammalian species. Comparison of the size of these amplified products, as determined by agarose gel electrophoresis, with those for which sequence data are available allowed us to estimate the number of repeats in the KS domain. In almost half the species examined, the KS domain consisted of 13 hexapeptide repeats.
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Affiliation(s)
- F P Barry
- Shriners' Hospital for Crippled Children, Tampa, Florida
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35
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Mörgelin M, Heinegård D, Engel J, Paulsson M. The cartilage proteoglycan aggregate: assembly through combined protein-carbohydrate and protein-protein interactions. Biophys Chem 1994; 50:113-28. [PMID: 8011926 DOI: 10.1016/0301-4622(94)85024-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In vitro reassembled aggregates of cartilage proteoglycan (aggrecan) were studied by glycerol spraying/rotary shadowing electron microscopy and compared to the corresponding native (i.e. never dissociated) structures. In both cases a tightly packed central filament structure was observed consisting of the hyaluronate binding region (HABR) of the proteoglycan, link protein (LP) and hyaluronate (HA). This differs from earlier results where a discontinuous central filament structure was seen after spreading proteoglycan aggregates at a water/air interphase. Binding of isolated HABR to HA is random but upon addition of link protein a clustering of the HA-binding proteins is observed, indicating a cooperativity. In a fully saturated aggregate the HA is covered by a continuous protein shell consisting of HABR and LP. When added in amounts below saturation HABR and LP bind to the HA in clusters which are interrupted by free strands of HA. The proteoglycan aggregate is thus an example for a structure where a polysaccharide forms a template for a supramolecular assembly largely stabilized by protein-protein interactions.
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Affiliation(s)
- M Mörgelin
- Department of Medical and Physiological Chemistry, University of Lund, Sweden
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Abstract
Large proteoglycans were purified by ion-exchange chromatography, gel filtration and CsCl gradient centrifugation from the compressed and tensional regions of adult bovine deep flexor tendon. Tryptic peptide maps of proteoglycan from the compressed region were very similar to maps of aggrecan from bovine articular cartilage, with evidence for the presence of all fifteen previously identified markers from the G1, G2 and G3 domains. The presence of aggrecan in these samples was confirmed by sequencing the G1 peptide YPIHTPR. The equivalent maps for large proteoglycan from tensional tendon were also consistent with the presence of aggrecan, and this was confirmed by sequencing three marker peptides from each of the G2 and G3 domains. However, G1 marker peptides were conspicuously absent from tensional samples. Northern blots for aggrecan mRNA showed high levels in cells from compressed tendon and articular cartilage. Extended exposure revealed a lower level of hybridization to RNA from tensional tendon as well. The results confirm that aggrecan, which is similar in core protein structure to articular cartilage aggrecan, is the predominant chondroitin sulfate-bearing large proteoglycan of compressed tendon. The results also indicate that aggrecan fragments lacking the G1 domain can account for the small amounts of chondroitin sulfate-bearing large proteoglycan in tensional regions of adult tendon.
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Affiliation(s)
- K G Vogel
- Department of Biology, University of New Mexico, Albuquerque
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37
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Upholt WB, Chandrasekaran L, Tanzer ML. Molecular cloning and analysis of the protein modules of aggrecans. EXS 1994; 70:37-52. [PMID: 8298251 DOI: 10.1007/978-3-0348-7545-5_4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The large aggregating chondroitin sulfate proteoglycan of cartilage, aggrecan, has served as a prototype of proteoglycan structure. Molecular cloning has elucidated its primary structure and revealed both known and unknown domains. To date the complete structures of chicken, rat and human aggrecans have been deduced, while partial sequences have been reported for bovine aggrecan. A related proteoglycan, human versican, has also been cloned and sequenced. Both aggrecan and versican have two lectin domains, one at the amino-terminus which binds hyaluronic acid and one at the carboxyl-terminus whose physiological ligand is unknown. Both lectins have homologous counterparts in other types of proteins. Within the aggrecans the keratan sulfate domain may be variably present and also has a prominent repeat in some species. The chondroitin sulfate domain has three distinct regions which vary in their prominence in different species. The complex molecular structure of aggrecans is consistent with the concept of exon shuffling and aggrecans serve as suitable prototypes for comprehending the evolution of multi-domain proteins.
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Affiliation(s)
- W B Upholt
- Department of BioStructure and Function, School of Dental Medicine, University of Connecticut Health Center, Farmington 06030-3705
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38
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Shapses SA, Sandell LJ, Ratcliffe A. Differential rates of aggrecan synthesis and breakdown in different zones of the bovine growth plate. Matrix Biol 1994; 14:77-86. [PMID: 8061922 DOI: 10.1016/0945-053x(94)90031-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study examines the basic metabolic events of aggrecan synthesis and breakdown in the growth plate at different depths and at different stages of development. Growth plate was harvested from the distal tibia of fetal and calf tissue and maintained as explants in serum-free-conditions. The tissue was sectioned into three equal depths (resting/proliferative zone, upper hypertrophic zone, and lower hypertrophic zone) and (a) cultured for three days with daily media change for studies of proteoglycan breakdown rates, or (b) incubated with [35S]-sulfate to determine relative rates of proteoglycan synthesis. Rates of both aggrecan synthesis and turnover were highest in the resting/proliferative zone compared to the upper or lower hypertrophic zones, and was greater in the calf compared to the fetal tissue. In situ hybridization studies showed that aggrecan gene expression in the cells of the resting/proliferative zone and the upper hypertrophic zones were similar, and was reduced in the deepest cells of the lower hypertrophic zone, adjacent to the zone of calcification. Proteoglycan structure was characterized by associative and dissociative Sepharose CL2B chromatography. These results showed that approximately 90% of the newly synthesized proteoglycan, and the total proteoglycan population, was able to aggregate and that the monomers were relatively large. The proteoglycan released into the media had a reduced ability to aggregate and the monomers were of a more variable size. These data support the hypothesis that the matrix proteoglycan content is controlled both by the rate of synthesis and breakdown, but in the lower regions the rate of synthesis may play a more dominant role. The higher metabolic activity of aggrecan in the calf than fetal growth plate may be a result of environmental stimuli (i.e., soluble mediators, loading) during different stages of development.
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Affiliation(s)
- S A Shapses
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ 08903
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Sandell LJ, Sugai JV, Trippel SB. Expression of collagens I, II, X, and XI and aggrecan mRNAs by bovine growth plate chondrocytes in situ. J Orthop Res 1994; 12:1-14. [PMID: 8113931 DOI: 10.1002/jor.1100120102] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The cells responsible for skeletal growth are the chondrocytes of the cartilaginous growth plate. These cells differentiate through a series of maturational stages, establishing different zones in the growth plate. Among the major functions of these cells is the production of appropriate extracellular matrix, primarily composed of collagens and proteoglycans. To determine whether matrix synthesis varies with respect to maturational stage and in which cell populations different collagens are expressed, bovine growth plates were analyzed by in situ hybridization to mRNA and by Northern blot hybridization. The most abundant collagen mRNA in the growth plate was type-II collagen. This mRNA was present at relatively low levels in the most immature cells of the growth plate but increased several-fold as cells entered the proliferative stage and remained high through subsequent phases of maturation. Type-XI collagen mRNA and mRNA for the cartilage-characteristic proteoglycan, aggrecan, were codistributed with the type-II collagen mRNA; however, both were present in much smaller quantities. Type-X procollagen mRNA was localized to chondrocytes late in their maturation and was expressed at levels similar to the expression of type-II collagen. In situ hybridization of serial sections revealed that growth plate chondrocytes in their more mature stages contain both type-II and type-X collagen mRNA. Type-I collagen mRNA was not observed in growth plate chondrocytes at any maturational stage; rather, it was localized to a morphologically distinct population of cells attached to calcifying cartilage septa in the region of vascular invasion.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L J Sandell
- Department of Orthopaedics, University of Washington, Seattle
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Abstract
The skeletal and corneal keratan sulfate proteoglycans show a different metabolic and structural heterogeneity. The domain structure of the carbohydrate chain has been shown to be different in various animal species. There are two major types of skeletal keratan sulfate proteoglycans with and without fucose. The protein cores of the corneal chicken keratan sulfate proteoglycan (lumican) and those of another small keratan sulfate proteoglycan (fibromodulin) have been sequenced. Keratan sulfate oligosaccharides belong to the members of an antigen family of the poly-N-acetyllactosamine series. Monoclonal antibodies and immunoassay procedures for keratan sulfate proteoglycans have been prepared. In osteoarthritis, no significant specific increase of keratan sulfate has been found. Keratan sulfate is a functional substitute for chondroitin sulfate in O2-deficient tissues.
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Affiliation(s)
- H Greiling
- Institute of Clinical Chemistry and Pathobiochemistry, Medical Faculty, University of Technology (RWTH), Aachen, Germany
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41
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Symposium. Clin Chem Lab Med 1994. [DOI: 10.1515/cclm.1994.32.4.215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Abstract
We have determined that synaptic vesicles contain a vesicle-specific keratan sulfate integral membrane proteoglycan. This is a major proteoglycan in electric organ synaptic vesicles. It exists in two forms on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, i.e., the L form, which migrates like a protein with an M(r) of 100,000, and the H form, with a lower mobility that migrates with an M(r) of approximately 250,000. Both forms contain SV2, an epitope located on the cytoplasmic side of the vesicle membrane. In addition to electric organ, we have analyzed the SV2 proteoglycan in vesicle fractions from two other sources, electric fish brain and rat brain. Both the H and L forms of SV2 are present in these vesicles and all are keratan sulfate proteoglycans. Unlike previously studied synaptic vesicle proteins, this proteoglycan contains a marker specific for a single group of neurons. This marker is an antigenically unique keratan sulfate side chain that is specific for the cells innervating the electric organ; it is not found on the synaptic vesicle keratan sulfate proteoglycan in other neurons of the electric fish brain.
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Affiliation(s)
- T W Scranton
- Department of Physiology and Biophysics, University of Washington, Seattle 98195
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Upholt WB, Chandrasekaran L, Tanzer ML. Molecular cloning and analysis of the protein modules of aggrecans. EXPERIENTIA 1993; 49:384-92. [PMID: 8500594 DOI: 10.1007/bf01923583] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The large aggregating chondroitin sulfate proteoglycan of cartilage, aggrecan, has served as a prototype of proteoglycan structure. Molecular cloning has elucidated its primary structure and revealed both known and unknown domains. To date the complete structures of chicken, rat and human aggrecans have been deduced, while partial sequences have been reported for bovine aggrecan. A related proteoglycan, human versican, has also been cloned and sequenced. Both aggrecan and versican have two lectin domains, one at the amino-terminus which binds hyaluronic acid and one at the carboxyl-terminus whose physiological ligand is unknown. Both lectins have homologous counterparts in other types of proteins. Within the aggrecans the keratan sulfate domain may be variably present and also has a prominent repeat in some species. The chondroitin sulfate domain has three distinct regions which vary in their prominence in different species. The complex molecular structure of aggrecans is consistent with the concept of exon shuffling and aggrecans serve as suitable prototypes for comprehending the evolution of multi-domain proteins.
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Affiliation(s)
- W B Upholt
- Department of BioStructure and Function, School of Dental Medicine, University of Connecticut Health Center, Farmington 06030-3705
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Calabro A, Hascall VC, Caterson B. Monoclonal antibodies directed against epitopes within the core protein structure of the large aggregating proteoglycan (aggrecan) from the swarm rat chondrosarcoma. Arch Biochem Biophys 1992; 298:349-60. [PMID: 1384430 DOI: 10.1016/0003-9861(92)90421-r] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The core protein of the large hyaline cartilage proteoglycan, aggrecan, is composed of six distinct domains: globular 1 (G1), interglobular, globular 2 (G2), keratan sulfate attachment, chondroitin sulfate (CS) attachment, and globular 3 (G3). Monoclonal antibodies that recognize epitopes in these domains were raised against Swarm rat chondrosarcoma aggrecan that was either denatured through reduction and alkylation or partially deglycosylated through chondroitinase ABC digestion or alkali elimination, the latter with or without sulfite addition. Monoclonal antibodies were further characterized for reactivity to purified aggrecan substructures including rat chondrosarcoma G1 and CS attachment domains, a recombinant rat chondrosarcoma G3 domain fusion protein, bovine articular cartilage G2 domain, and rat chondrosarcoma link protein (LP). Biochemical characterization of the specificities of these monoclonal antibodies indicated that one (1C6) recognized an epitope shared by both the G1 and the G2 domains; one (5C4) recognized an epitope shared by both LP and the G1 domain; one (7D1) recognized an epitope shared by both the G1 and the CS attachment domains; two (14A1 and 15B2) recognized epitopes in the CS attachment domain; one (14B4) recognized an epitope in the G3 domain; and one (13D1) recognized a ubiquitous epitope shared by the G1, G2, G3, and CS attachment domains of aggrecan and also LP. Collectively the specificities of these antibodies confirm the occurrence of multiple repeated epitopes (both carbohydrate and protein in nature) throughout the different domain structures of aggrecan. These antibodies have been proven to be useful for identifying aggrecan-like molecules in several connective tissues other than cartilage.
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Affiliation(s)
- A Calabro
- Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892
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Blochberger T, Cornuet P, Hassell J. Isolation and partial characterization of lumican and decorin from adult chicken corneas. A keratan sulfate-containing isoform of decorin is developmentally regulated. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)36731-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Kazama T, Takagi M, Ishii T, Toda Y. Immunoelectron microscopic studies of glycosaminoglycans in the metaphyseal bone trabeculae of growing rats. THE HISTOCHEMICAL JOURNAL 1992; 24:747-55. [PMID: 1429000 DOI: 10.1007/bf01460827] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The types and distribution of glycosaminoglycans (GAGs) were studied immunocytochemically in osteoid, mineralized bone matrix, and cartilage matrix of growing rat metaphyseal bone after aldehyde fixation and EDTA demineralization, using four monoclonal antibodies (mAbs 1-B-5, 2-B-6, 3-B-3 and 5-D-4). These mAbs specifically recognize epitopes in non-sulphated chondroitin (C0-S); chondroitin 4-sulphate (C4-S) and dermatan sulphate (DS); chondroitin 6-sulphate (C6-S) and C0-S; and keratan sulphate (KS) respectively. In osteoid, all mAbs except 1-B-5 weakly stained matrix material on and between collagen fibrils, and moderately stained organic material corresponding to bone nodules, which are known sites of mineralization. However, the staining of osteoid abruptly decreased at the mineralization front; weak staining was confined mostly to the organic material of bone nodules in mineralized bone matrix, with very weak or no staining of the rest of the bone matrix. This staining progressively decreased toward the mineralized cartilage matrix and became negative. The mineralized cartilage matrix and lamina limitans reacted strongly with all mAbs except 5-D-4. These results indicate that osteoid contains sulphated proteoglycans containing C4-S and/or DS, C6-S and KS, and subsequent bone matrix mineralization appears to require accumulation of these macromolecules within bone nodules and eventual loss of these substances for complete mineralization, whereas proteoglycans containing C0-S, C4-S and/or DS, and C6-S still exist in mineralized cartilage matrix and lamina limitans.
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Affiliation(s)
- T Kazama
- Department of Oral Surgery, Nihon University School of Dentistry, Tokyo, Japan
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48
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49
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Mörgelin M, Engel J, Heinegård D, Paulsson M. Proteoglycans from the swarm rat chondrosarcoma. Structure of the aggregates extracted with associative and dissociative solvents as revealed by electron microscopy. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)49709-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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50
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Mason MD, Pera MF. Immunohistochemical and biochemical characterisation of the expression of a human embryonal carcinoma cell proteoglycan antigen in human germ cell tumours and other tissues. Eur J Cancer 1992; 28A:1090-8. [PMID: 1320911 DOI: 10.1016/0959-8049(92)90464-d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the embryonal carcinoma (EC) cell line GCT 27, monoclonal antibody GCTM-2 recognises an epitope on a 200 kD pericellular matrix keratan sulphate proteoglycan. Immunohistochemical analyses demonstrated staining of tissue sections from 21 out of 22 human non-seminomatous germ cell tumours, and from 22 out of 28 sections of seminomas. In normal human fetal tissues gut epithelium and muscle stained strongly, and certain other epithelia stained moderately. In adult tissues, the distribution of the epitope was similar, but staining intensity was weaker. Neoplastic tissues showed reactivity with embryonal rhabdomyosarcoma and colorectal carcinoma, but no other non-germ cell tumours. Immunofluorescence microscopy showed that GCTM-2 also stained cell lines from human colorectal carcinoma, embryonal rhabdomyosarcoma and choriocarcinoma. In contrast to EC cells the epitope in these other cell types required permeabilization of the cells to be visualised, and the protein bands in immunoblots lacked extensive modification with keratan sulphate and were smaller. Thus, GCTM-2 reacts with an epitope which has a previously unrecognised tissue distribution; its expression as a pericellular matrix proteoglycan is predominantly a characteristic of human EC cells.
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Affiliation(s)
- M D Mason
- Velindre Hospital, Cardiff, South Glamorgan, U.K
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