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Adam M, Urbanski HF, Garyfallou VT, Welsch U, Köhn FM, Ullrich Schwarzer J, Strauss L, Poutanen M, Mayerhofer A. High levels of the extracellular matrix proteoglycan decorin are associated with inhibition of testicular function. ACTA ACUST UNITED AC 2011; 35:550-61. [PMID: 22413766 DOI: 10.1111/j.1365-2605.2011.01225.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Decorin (DCN), a component of the extracellular matrix of the peritubular wall and the interstitial areas of the human testis, can interact with growth factor (GF) signalling, thereby blocking downstream actions of GFs. In the present study the expression and regulation of DCN using both human testes and two experimental animal models, namely the rhesus monkey and mouse, were examined. DCN protein was present in peritubular and interstitial areas of adult human and monkey testes, while it was almost undetectable in adult wild type mice. Interestingly, the levels and sites of testicular DCN expression in the monkeys were inversely correlated with testicular maturation markers. A strong DCN expression associated with the abundant connective tissue of the interstitial areas in the postnatal through pre-pubertal phases was observed. In adult and old monkeys the DCN pattern was similar to the one in normal human testes, presenting strong expression at the peritubular region. In the testes of both infertile men and in a mouse model of inflammation associated infertility (aromatase-overexpressing transgenic mice), the fibrotic changes and increased numbers of tumour necrosis factor (TNF)-α-producing immune cells were shown to be associated with increased production of DCN. Furthermore, studies with human testicular peritubular cells isolated from fibrotic testis indicated that TNF-α significantly increased DCN production. The data, thus, show that an increased DCN level is associated with impaired testicular function, supporting our hypothesis that DCN interferes with paracrine signalling of the testis in health and disease.
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Affiliation(s)
- M Adam
- Anatomy and Cell Biology, Ludwig-Maximilians-University Munich, Munich, Germany
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102
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Kajander T, Kuja-Panula J, Rauvala H, Goldman A. Crystal Structure and Role of Glycans and Dimerization in Folding of Neuronal Leucine-Rich Repeat Protein AMIGO-1. J Mol Biol 2011; 413:1001-15. [DOI: 10.1016/j.jmb.2011.09.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 09/13/2011] [Accepted: 09/15/2011] [Indexed: 10/17/2022]
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103
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Ang LS, Boivin WA, Williams SJ, Zhao H, Abraham T, Carmine-Simmen K, McManus BM, Bleackley RC, Granville DJ. Serpina3n attenuates granzyme B-mediated decorin cleavage and rupture in a murine model of aortic aneurysm. Cell Death Dis 2011; 2:e209. [PMID: 21900960 PMCID: PMC3186906 DOI: 10.1038/cddis.2011.88] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Granzyme B (GZMB) is a proapoptotic serine protease that is released by cytotoxic lymphocytes. However, GZMB can also be produced by other cell types and is capable of cleaving extracellular matrix (ECM) proteins. GZMB contributes to abdominal aortic aneurysm (AAA) through an extracellular, perforin-independent mechanism involving ECM cleavage. The murine serine protease inhibitor, Serpina3n (SA3N), is an extracellular inhibitor of GZMB. In the present study, administration of SA3N was assessed using a mouse Angiotensin II-induced AAA model. Mice were injected with SA3N (0–120 μg/kg) before pump implantation. A significant dose-dependent reduction in the frequency of aortic rupture and death was observed in mice that received SA3N treatment compared with controls. Reduced degradation of the proteoglycan decorin was observed while collagen density was increased in the aortas of mice receiving SA3N treatment compared with controls. In vitro studies confirmed that decorin, which regulates collagen spacing and fibrillogenesis, is cleaved by GZMB and that its cleavage can be prevented by SA3N. In conclusion, SA3N inhibits GZMB-mediated decorin degradation leading to enhanced collagen remodelling and reinforcement of the adventitia, thereby reducing the overall rate of rupture and death in a mouse model of AAA.
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Affiliation(s)
- L S Ang
- Institute for Heart and Lung Health, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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104
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Bertassoni LE, Stankoska K, Swain MV. Insights into the structure and composition of the peritubular dentin organic matrix and the lamina limitans. Micron 2011; 43:229-36. [PMID: 21890367 DOI: 10.1016/j.micron.2011.08.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 06/17/2011] [Accepted: 08/08/2011] [Indexed: 10/17/2022]
Abstract
Dentin is a mineralized dental tissue underlying the outer enamel that has a peculiar micro morphology. It is composed of micrometer sized tubules that are surrounded by a highly mineralized structure, called peritubular dentin (PTD), and embedded in a collagen-rich matrix, named intertubular dentin. The PTD has been thought to be composed of a highly mineralized collagen-free organic matrix with unknown composition. Here we tested the hypothesis that proteoglycans and glycosaminoglycans, two important organic structural features found in dentin, are key participants in the microstructure and composition of the PTD. To test this hypothesis dentin blocks were demineralized with 10 vol% citric acid for 2 min and either digested with 1mg/ml TPCK-treated trypsin with 0.2 ammonium bicarbonate at pH 7.9 (TRY) or 0.1 U/mL C-ABC with 50mM Tris, 60mM sodium acetate and 0.02% bovine serum albumin at pH 8.0 (C-ABC). TRY is known to cleave the protein core of dentin proteoglycans, whereas C-ABC is expected to selectively remove glycosaminoglycans. All specimens were digested for 48 h in 37°C, dehydrated in ascending grades of acetone, immersed in HMDS, platinum coated and imaged using an FE-SEM. Images of demineralized dentin revealed a meshwork of noncollagenous fibrils protruding towards the tubule lumen following removal of the peritubular mineral and confirmed the lack of collagen in the peritubular matrix. Further, images revealed that the peritubular organic network originates from a sheet-like membrane covering the entire visible length of tubule, called lamina limitans. Confirming our initial hypothesis, after the digestion with C-ABC the organic network appeared to vanish, while the lamina limitans was preserved. This suggests that glycosaminoglycans are the main component of the PTD organic network. Following digestion with TRY, both the organic network and the lamina limitans disappeared, thus suggesting that the lamina limitans may be primarily composed of proteoglycan protein cores. In summary, our results provide novel evidence that (1) PTD lacks collagen fibrils, (2) PTD contains an organic scaffold embedded with mineral and (3) the PTD organic matrix is manly composed of glycosaminoglycans, whereas the lamina limitans is primarily made of proteoglycans protein cores.
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Affiliation(s)
- Luiz Eduardo Bertassoni
- Biomaterials Research Unit, Faculty of Dentistry, University of Sydney, Sydney Dental Hospital, 2 Chalmers Street, Surry Hills, NSW 2010, Australia.
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105
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Friebe VM, Mikulis B, Kole S, Ruffing CS, Sacks MS, Vyavahare NR. Neomycin enhances extracellular matrix stability of glutaraldehyde crosslinked bioprosthetic heart valves. J Biomed Mater Res B Appl Biomater 2011; 99:217-29. [DOI: 10.1002/jbm.b.31889] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 01/13/2011] [Accepted: 02/10/2011] [Indexed: 11/08/2022]
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106
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Orgel J, Antipova O, Sagi I, Bitler A, Qiu D, Wang R, Xu Y, San Antonio J. Collagen fibril surface displays a constellation of sites capable of promoting fibril assembly, stability, and hemostasis. Connect Tissue Res 2011; 52:18-24. [PMID: 21117898 PMCID: PMC3244825 DOI: 10.3109/03008207.2010.511354] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Fibrillar collagens form the structural basis of organs and tissues including the vasculature, bone, and tendon. They are also dynamic, organizational scaffolds that present binding and recognition sites for ligands, cells, and platelets. We interpret recently published X-ray diffraction findings and use atomic force microscopy data to illustrate the significance of new insights into the functional organization of the collagen fibril. These data indicate that collagen's most crucial functional domains localize primarily to the overlap region, comprising a constellation of sites we call the "master control region." Moreover, the collagen's most exposed aspect contains its most stable part-the C-terminal region that controls collagen assembly, cross-linking, and blood clotting. Hidden beneath the fibril surface exists a constellation of "cryptic" sequences poised to promote hemostasis and cell-collagen interactions in tissue injury and regeneration. These findings begin to address several important, and previously unresolved, questions: How functional domains are organized in the fibril, which domains are accessible, and which require proteolysis or structural trauma to become exposed? Here we speculate as to how collagen fibrillar organization impacts molecular processes relating to tissue growth, development, and repair.
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Affiliation(s)
- J.P.R.O Orgel
- Pritzker Institute of Biomedical Science and Engineering, Illinois Institute of Technology, Chicago, IL, USA.,Department of Biological, Chemical and Physical Sciences, Illinois Institute of Technology, Chicago, IL, USA.,Corresponding Authors: J.P.R.O. Orgel () and J.D. San Antonio ()
| | - O. Antipova
- Pritzker Institute of Biomedical Science and Engineering, Illinois Institute of Technology, Chicago, IL, USA.,Department of Biological, Chemical and Physical Sciences, Illinois Institute of Technology, Chicago, IL, USA
| | - I Sagi
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - A. Bitler
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - D. Qiu
- Department of Biological, Chemical and Physical Sciences, Illinois Institute of Technology, Chicago, IL, USA
| | - R. Wang
- Department of Biological, Chemical and Physical Sciences, Illinois Institute of Technology, Chicago, IL, USA
| | - Y. Xu
- Department of Chemistry, Hunter College, CUNY, NY, USA
| | - J.D. San Antonio
- Operations, Orthovita, Inc., Malvern, PA, USA.,Corresponding Authors: J.P.R.O. Orgel () and J.D. San Antonio ()
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107
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Orgel JPRO, San Antonio JD, Antipova O. Molecular and structural mapping of collagen fibril interactions. Connect Tissue Res 2011; 52:2-17. [PMID: 21182410 DOI: 10.3109/03008207.2010.511353] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The fibrous collagens form the structural basis of all mammalian connective tissues, including the vasculature, dermis, bones, tendons, cartilage, and those tissues that support organs such as the heart, kidneys, liver, and lungs. The helical structure of collagen has been extensively studied but in addition to its helical character, its molecular packing arrangement (in its aggregated or fibrillar form) and the presence of specific amino acid sequences govern collagen's in vivo functions. Collagen's molecular packing arrangement helps control cellular communication, attachment and movement, and conveys its tissue-specific biomechanical properties. Recent progress in understanding collagen's molecular packing, fibrillar structure, domain organization, and extracellular matrix (ECM) interactions in light of X-ray fiber diffraction data provides significant new insights into how the ECM is organized and functions. In this review, the hierarchy of fibrillar collagen structure is discussed in the context of how this organization affects ECM-"ligand" interactions, with specific attention to collagenolysis, integrins, fibronection, glycoprotein VI receptor (GPVI), and proteoglycans (PG). Understanding the complex structure of collagen and its attached ligands should provide new insights into tissue growth, development, regeneration, and disease.
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Affiliation(s)
- J P R O Orgel
- Pritzker Institute of Biomedical Science and Engineering, Illinois Institute of Technology, Chicago, IL 60616, USA.
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108
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Kalamajski S, Oldberg A. The role of small leucine-rich proteoglycans in collagen fibrillogenesis. Matrix Biol 2010; 29:248-53. [PMID: 20080181 DOI: 10.1016/j.matbio.2010.01.001] [Citation(s) in RCA: 312] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 01/04/2010] [Accepted: 01/07/2010] [Indexed: 01/13/2023]
Abstract
Small leucine-rich proteoglycans/proteins (SLRPs) are associated with collagen fibril formation, and therefore important for the proper formation of extracellular matrices. SLRPs are differentially expressed in tissues and during pathological conditions, contributing to the development of connective tissue properties. The binding of SLRPs to collagens have recently been characterized, and may give some clues to the significance of these interactions. In this mini review, we summarize published work in this field, and propose several mechanisms for how SLRPs can control collagen matrix structure and function. SLRPs appear to influence collagen cross-linking patterns. We also propose that the SLRP-collagen interactions can assist in the process of juxtaposing the collagen monomers by steric hindrance or by directly connecting two collagen monomers during the fibril growth.
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Affiliation(s)
- Sebastian Kalamajski
- Lund University, Department of Experimental Medical Science, BMC B12, Lund, Sweden.
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109
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Antipova O, Orgel JPRO. In situ D-periodic molecular structure of type II collagen. J Biol Chem 2010; 285:7087-96. [PMID: 20056598 DOI: 10.1074/jbc.m109.060400] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Collagens are essential components of extracellular matrices in multicellular animals. Fibrillar type II collagen is the most prominent component of articular cartilage and other cartilage-like tissues such as notochord. Its in situ macromolecular and packing structures have not been fully characterized, but an understanding of these attributes may help reveal mechanisms of tissue assembly and degradation (as in osteo- and rheumatoid arthritis). In some tissues such as lamprey notochord, the collagen fibrillar organization is naturally crystalline and may be studied by x-ray diffraction. We used diffraction data from native and derivative notochord tissue samples to solve the axial, D-periodic structure of type II collagen via multiple isomorphous replacement. The electron density maps and heavy atom data revealed the conformation of the nonhelical telopeptides and the overall D-periodic structure of collagen type II in native tissues, data that were further supported by structure prediction and transmission electron microscopy. These results help to explain the observed differences in collagen type I and type II fibrillar architecture and indicate the collagen type II cross-link organization, which is crucial for fibrillogenesis. Transmission electron microscopy data show the close relationship between lamprey and mammalian collagen fibrils, even though the respective larger scale tissue architecture differs.
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Affiliation(s)
- Olga Antipova
- Center for Molecular Study of Condensed Soft Matter Centers (microCoSM), Pritzker Institute of Biomedical Science and Engineering, Chicago, Illinois 60616, USA.
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110
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Affiliation(s)
- Kenji OKUYAMA
- Department of Macromolecular Science, Osaka University
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