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Chatham JC, Patel RP. Protein glycosylation in cardiovascular health and disease. Nat Rev Cardiol 2024:10.1038/s41569-024-00998-z. [PMID: 38499867 DOI: 10.1038/s41569-024-00998-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/13/2024] [Indexed: 03/20/2024]
Abstract
Protein glycosylation, which involves the attachment of carbohydrates to proteins, is one of the most abundant protein co-translational and post-translational modifications. Advances in technology have substantially increased our knowledge of the biosynthetic pathways involved in protein glycosylation, as well as how changes in glycosylation can affect cell function. In addition, our understanding of the role of protein glycosylation in disease processes is growing, particularly in the context of immune system function, infectious diseases, neurodegeneration and cancer. Several decades ago, cell surface glycoproteins were found to have an important role in regulating ion transport across the cardiac sarcolemma. However, with very few exceptions, our understanding of how changes in protein glycosylation influence cardiovascular (patho)physiology remains remarkably limited. Therefore, in this Review, we aim to provide an overview of N-linked and O-linked protein glycosylation, including intracellular O-linked N-acetylglucosamine protein modification. We discuss our current understanding of how all forms of protein glycosylation contribute to normal cardiovascular function and their roles in cardiovascular disease. Finally, we highlight potential gaps in our knowledge about the effects of protein glycosylation on the heart and vascular system, highlighting areas for future research.
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Affiliation(s)
- John C Chatham
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Rakesh P Patel
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
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2
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Maiti G, Ashworth S, Choi T, Chakravarti S. Molecular cues for immune cells from small leucine-rich repeat proteoglycans in their extracellular matrix-associated and free forms. Matrix Biol 2023; 123:48-58. [PMID: 37793508 PMCID: PMC10841460 DOI: 10.1016/j.matbio.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/14/2023] [Accepted: 10/01/2023] [Indexed: 10/06/2023]
Abstract
In this review we highlight emerging immune regulatory functions of lumican, keratocan, fibromodulin, biglycan and decorin, which are members of the small leucine-rich proteoglycans (SLRP) of the extracellular matrix (ECM). These SLRPs have been studied extensively as collagen-fibril regulatory structural components of the skin, cornea, bone and cartilage in homeostasis. However, SLRPs released from a remodeling ECM, or synthesized by activated fibroblasts and immune cells contribute to an ECM-free pool in tissues and circulation, that may have a significant, but poorly understood foot print in inflammation and disease. Their molecular interactions and the signaling networks they influence also require investigations. Here we present studies on the leucine-rich repeat (LRR) motifs of SLRP core proteins, their evolutionary and functional relationships with other LRR pathogen recognition receptors, such as the toll-like receptors (TLRs) to bring some molecular clarity in the immune regulatory functions of SLRPs. We discuss molecular interactions of fragments and intact SLRPs, and how some of these interactions are likely modulated by glycosaminoglycan side chains. We integrate findings on molecular interactions of these SLRPs together with what is known about their presence in circulation and lymph nodes (LN), which are important sites of immune cell regulation. Recent bulk and single cell RNA sequencing studies have identified subsets of stromal reticular cells that express these SLRPs within LNs. An understanding of the cellular source, molecular interactions and signaling consequences will lead to a fundamental understanding of how SLRPs modulate immune responses, and to therapeutic tools based on these SLRPs in the future.
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Affiliation(s)
- George Maiti
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, NY, United States
| | - Sean Ashworth
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, NY, United States
| | - Tansol Choi
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, NY, United States
| | - Shukti Chakravarti
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, NY, United States; Department of Pathology, NYU Grossman School of Medicine, New York, NY, United States.
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3
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Gesteira TF, Verma S, Coulson-Thomas VJ. Small leucine rich proteoglycans: Biology, function and their therapeutic potential in the ocular surface. Ocul Surf 2023; 29:521-536. [PMID: 37355022 PMCID: PMC11092928 DOI: 10.1016/j.jtos.2023.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/13/2023] [Accepted: 06/21/2023] [Indexed: 06/26/2023]
Abstract
Small leucine rich proteoglycans (SLRPs) are the largest family of proteoglycans, with 18 members that are subdivided into five classes. SLRPs are small in size and can be present in tissues as glycosylated and non-glycosylated proteins, and the most studied SLRPs include decorin, biglycan, lumican, keratocan and fibromodulin. SLRPs specifically bind to collagen fibrils, regulating collagen fibrillogenesis and the biomechanical properties of tissues, and are expressed at particularly high levels in fibrous tissues, such as the cornea. However, SLRPs are also very active components of the ECM, interacting with numerous growth factors, cytokines and cell surface receptors. Therefore, SLRPs regulate major cellular processes and have a central role in major fundamental biological processes, such as maintaining corneal homeostasis and transparency and regulating corneal wound healing. Over the years, mutations and/or altered expression of SLRPs have been associated with various corneal diseases, such as congenital stromal corneal dystrophy and cornea plana. Recently, there has been great interest in harnessing the various functions of SLRPs for therapeutic purposes. In this comprehensive review, we describe the structural features and the related functions of SLRPs, and how these affect the therapeutic potential of SLRPs, with special emphasis on the use of SLRPs for treating ocular surface pathologies.
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Affiliation(s)
| | - Sudhir Verma
- College of Optometry, University of Houston, USA; Department of Zoology, Deen Dayal Upadhyaya College, University of Delhi, Delhi, India
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4
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Santos FM, Ciordia S, Mesquita J, Cruz C, Sousa JPCE, Passarinha LA, Tomaz CT, Paradela A. Proteomics profiling of vitreous humor reveals complement and coagulation components, adhesion factors, and neurodegeneration markers as discriminatory biomarkers of vitreoretinal eye diseases. Front Immunol 2023; 14:1107295. [PMID: 36875133 PMCID: PMC9978817 DOI: 10.3389/fimmu.2023.1107295] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/01/2023] [Indexed: 02/18/2023] Open
Abstract
Introduction Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are leading causes of visual impairment and blindness in people aged 50 years or older in middle-income and industrialized countries. Anti-VEGF therapies have improved the management of neovascular AMD (nAMD) and proliferative DR (PDR), no treatment options exist for the highly prevalent dry form of AMD. Methods To unravel the biological processes underlying these pathologies and to find new potential biomarkers, a label-free quantitative (LFQ) method was applied to analyze the vitreous proteome in PDR (n=4), AMD (n=4) compared to idiopathic epiretinal membranes (ERM) (n=4). Results and discussion Post-hoc tests revealed 96 proteins capable of differentiating among the different groups, whereas 118 proteins were found differentially regulated in PDR compared to ERM and 95 proteins in PDR compared to dry AMD. Pathway analysis indicates that mediators of complement, coagulation cascades and acute phase responses are enriched in PDR vitreous, whilst proteins highly correlated to the extracellular matrix (ECM) organization, platelet degranulation, lysosomal degradation, cell adhesion, and central nervous system development were found underexpressed. According to these results, 35 proteins were selected and monitored by MRM (multiple reaction monitoring) in a larger cohort of patients with ERM (n=21), DR/PDR (n=20), AMD (n=11), and retinal detachment (n=13). Of these, 26 proteins could differentiate between these vitreoretinal diseases. Based on Partial least squares discriminant and multivariate exploratory receiver operating characteristic (ROC) analyses, a panel of 15 discriminatory biomarkers was defined, which includes complement and coagulation components (complement C2 and prothrombin), acute-phase mediators (alpha-1-antichymotrypsin), adhesion molecules (e.g., myocilin, galectin-3-binding protein), ECM components (opticin), and neurodegeneration biomarkers (beta-amyloid, amyloid-like protein 2).
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Affiliation(s)
- Fátima M Santos
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal.,Functional Proteomics Laboratory, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - Sergio Ciordia
- Functional Proteomics Laboratory, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - Joana Mesquita
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Carla Cruz
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal.,Chemistry Department, Faculty of Sciences, University of Beira Interior, Covilhã, Portugal
| | - João Paulo Castro E Sousa
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal.,Department of Ophthalmology, Centro Hospitalar de Leiria, Leiria, Portugal
| | - Luís A Passarinha
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculdade de Ciências e Tecnologia, Universidade NOVA, Caparica, Portugal.,UCIBIO-Applied Molecular Biosciences Unit, Departamento de Química/Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal.,Laboratório de Fármaco-Toxicologia, UBIMedical, Universidade da Beira Interior, Covilhã, Portugal
| | - Cândida T Tomaz
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal.,Chemistry Department, Faculty of Sciences, University of Beira Interior, Covilhã, Portugal
| | - Alberto Paradela
- Functional Proteomics Laboratory, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
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5
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Klotzsche-von Ameln A, Sprott D. Harnessing retinal phagocytes to combat pathological neovascularization in ischemic retinopathies? Pflugers Arch 2022; 474:575-590. [PMID: 35524802 PMCID: PMC9117346 DOI: 10.1007/s00424-022-02695-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/28/2022] [Indexed: 12/12/2022]
Abstract
Ischemic retinopathies (IR) are vision-threatening diseases that affect a substantial amount of people across all age groups worldwide. The current treatment options of photocoagulation and anti-VEGF therapy have side effects and are occasionally unable to prevent disease progression. It is therefore worthwhile to consider other molecular targets for the development of novel treatment strategies that could be safer and more efficient. During the manifestation of IR, the retina, normally an immune privileged tissue, encounters enhanced levels of cellular stress and inflammation that attract mononuclear phagocytes (MPs) from the blood stream and activate resident MPs (microglia). Activated MPs have a multitude of effects within the retinal tissue and have the potential to both counter and exacerbate the harmful tissue microenvironment. The present review discusses the current knowledge about the role of inflammation and activated retinal MPs in the major IRs: retinopathy of prematurity and diabetic retinopathy. We focus particularly on MPs and their secreted factors and cell–cell-based interactions between MPs and endothelial cells. We conclude that activated MPs play a major role in the manifestation and progression of IRs and could therefore become a promising new target for novel pharmacological intervention strategies in these diseases.
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Affiliation(s)
| | - David Sprott
- Institute of Physiology, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.
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6
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Chen Y, Xia Q, Zeng Y, Zhang Y, Zhang M. Regulations of Retinal Inflammation: Focusing on Müller Glia. Front Cell Dev Biol 2022; 10:898652. [PMID: 35573676 PMCID: PMC9091449 DOI: 10.3389/fcell.2022.898652] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 04/11/2022] [Indexed: 12/12/2022] Open
Abstract
Retinal inflammation underlies multiple prevalent retinal diseases. While microglia are one of the most studied cell types regarding retinal inflammation, growing evidence shows that Müller glia play critical roles in the regulation of retinal inflammation. Müller glia express various receptors for cytokines and release cytokines to regulate inflammation. Müller glia are part of the blood-retinal barrier and interact with microglia in the inflammatory responses. The unique metabolic features of Müller glia in the retina makes them vital for retinal homeostasis maintenance, regulating retinal inflammation by lipid metabolism, purine metabolism, iron metabolism, trophic factors, and antioxidants. miRNAs in Müller glia regulate inflammatory responses via different mechanisms and potentially regulate retinal regeneration. Novel therapies are explored targeting Müller glia for inflammatory retinal diseases treatment. Here we review new findings regarding the roles of Müller glia in retinal inflammation and discuss the related novel therapies for retinal diseases.
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Affiliation(s)
- Yingying Chen
- Department of Ophthalmology, Sichuan University West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Qinghong Xia
- Operating Room of Anesthesia Surgery Center, West China Hospital, Sichuan University, Chengdu, China
- West China School of Nursing, Sichuan University, Chengdu, China
| | - Yue Zeng
- Department of Ophthalmology, Sichuan University West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Yun Zhang
- Department of Ophthalmology, Sichuan University West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Meixia Zhang
- Department of Ophthalmology, Sichuan University West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Meixia Zhang,
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7
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Liu X, Xing Y, Liu X, Zeng L, Ma J. Opticin Ameliorates Hypoxia-Induced Retinal Angiogenesis by Suppression of Integrin α2-I Domain-Collagen Complex Formation and RhoA/ROCK1 Signaling. Invest Ophthalmol Vis Sci 2022; 63:13. [PMID: 35006271 PMCID: PMC8762695 DOI: 10.1167/iovs.63.1.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Purpose It was previously demonstrated that opticin (OPTC) inhibits the collagen-induced promotion of bioactivities of human retinal vascular endothelial cells (hRVECs). The present in vivo study aimed to further investigate the regulatory role of opticin in vitreous collagen-mediated retinal neovascularization and to elucidate its regulatory mechanisms with regard to integrin α2-I domain–GXXGER complex formation and RhoA/ROCK1 signal change. The regulatory role of Mg2+ on integrin α2-I domain–GXXGER complex formation in the above process was also investigated. Methods The zebrafish model of hypoxia-induced retinopathy was established, and OPTC-overexpressing plasmids were intravitreally injected to assess the antiangiogenesis effect of opticin. The regulatory role of opticin in integrin α2-I domain–GXXGER complex formation in vivo was analyzed by mass spectrometry. The mRNA and protein expression of RhoA/ROCK1 were examined. The concentration of Mg2+ as an activator of the integrin α2-I domain–GXXGER complex was measured. Solid-phase binding assays were performed to investigate the interference of opticin in integrin α2 collagen binding and the regulatory role of Mg2+ in that process. Results Opticin and OPTC-overexpressing plasmid injection reduced retinal neovascularization in the zebrafish model of hypoxia-induced retinopathy. Mass spectrometry revealed that opticin could inhibit integrin α2-I domain–GXXGER complex formation. The Mg2+ concentration was also decreased by opticin, which was another indication of the complex activation. Injection of OPTC-overexpressing plasmids inhibited mRNA and the protein expression of RhoA/ROCK1 in the zebrafish model of hypoxia-induced retinopathy. The solid-phase binding assay revealed that opticin could block integrin α2–collagen I binding in the presence of Mg2+. Conclusions Opticin exerts its antiangiogenesis effect by interfering in the Mg2+-modulated integrin α2-I domain–collagen complex formation and suppressing the downstream RhoA/ ROCK1 signaling pathway.
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Affiliation(s)
- Xiaoxue Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yue Xing
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xin Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Lingyan Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jin Ma
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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8
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Klaska IP, White A, Villacampa P, Hoke J, Hervás LA, Maswood RN, Ali RR, Bunce C, Unwin RD, Cooper GJS, Bishop PN, Bainbridge JW. Intravitreal administration of recombinant human opticin protects against hyperoxia-induced pre-retinal neovascularization. Exp Eye Res 2021; 215:108908. [PMID: 34954204 PMCID: PMC8935380 DOI: 10.1016/j.exer.2021.108908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/29/2021] [Accepted: 12/20/2021] [Indexed: 01/01/2023]
Abstract
Opticin is an extracellular glycoprotein present in the vitreous. Its antiangiogenic properties offer the potential for therapeutic intervention in conditions such as proliferative diabetic retinopathy and retinopathy of prematurity. Here, we investigated the hypothesis that intravitreal administration of recombinant human opticin can safely protect against the development of pathological angiogenesis and promote its regression. We generated and purified recombinant human opticin and investigated its impact on the development and regression of pathological retinal neovascularization following intravitreal administration in murine oxygen-induced retinopathy. We also investigated its effect on normal retinal vascular development and function, following intravitreal injection in neonatal mice, by histological examination and electroretinography. In oxygen-induced retinopathy, intravitreal administration of human recombinant opticin protected against the development of retinal neovascularization to similar extent as aflibercept, which targets VEGF. Opticin also accelerated regression of established retinal neovascularization, though the effect at 18 h was less than that of aflibercept. Intravitreal administration of human recombinant opticin in neonatal mice caused no detectable perturbation of subsequent retinal vascular development or function. In summary we found that intraocular administration of recombinant human opticin protects against the development of pathological angiogenesis in mice and promotes its regression.
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Affiliation(s)
- Izabela P Klaska
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK; KCL Centre for Cell and Gene Therapy, Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Anne White
- Division of Evolution & Genomic Sciences, School of Biological Sciences, FBMH, University of Manchester, Manchester, UK
| | - Pilar Villacampa
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK; Josep Carreras Leukaemia Research Institute, Ctra de Can Ruti, Barcelona, Spain
| | - Justin Hoke
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Laura A Hervás
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Ryea N Maswood
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Robin R Ali
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK; KCL Centre for Cell and Gene Therapy, Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Catey Bunce
- School of Population Health and Environmental Sciences, Faculty of Life Sciences and Medicine, King's College London, Addison House, London, SE1 1UL, UK
| | - Richard D Unwin
- Division of Cardiovascular Sciences, School of Medical Sciences, FBMH, University of Manchester, Manchester, UK; Stoller Biomarker Discovery Centre and Division of Cancer Sciences, School of Medical Sciences, FBMH, University of Manchester, Manchester, UK
| | - Garth J S Cooper
- Division of Cardiovascular Sciences, School of Medical Sciences, FBMH, University of Manchester, Manchester, UK
| | - Paul N Bishop
- Division of Evolution & Genomic Sciences, School of Biological Sciences, FBMH, University of Manchester, Manchester, UK; Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - James W Bainbridge
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.
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9
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Matyushchenko AG, Budzinskaya MV, Petrachkov DV. [Modern understanding of structural and biochemical characteristics of the vitreous in eyes with normal and increased axial length]. Vestn Oftalmol 2021; 137:110-115. [PMID: 34410065 DOI: 10.17116/oftalma2021137041110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The review highlights the features of molecular, morphological and anatomical organization of the vitreous body in normal human eyes and in eyes with elongated anterior-posterior axis. The molecular structure of the vitreous consists of various types of collagen, glycosaminoglycans, glycoproteins and proteoglycans. The lowest concentration of collagen fibrils is in the central vitreous, so the structural changes of vitreous gel associated with attenuation of the vitreous body happen there much earlier and to a greater degree. Increased aggregation of collagen fibrils with age casuses an increase of liquid fractions of the vitreous with a concomitant decrease in gel volume. Similar processes occur earlier in eyes with axial myopia. Destructive processes in myopia increase progressively with axial elongation. As a result of vitreous collapse, vitreoretinal adhesion weakens and posterior vitreous detachment occurs.
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10
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Small Leucine-Rich Proteoglycans (SLRPs) in the Retina. Int J Mol Sci 2021; 22:ijms22147293. [PMID: 34298915 PMCID: PMC8305803 DOI: 10.3390/ijms22147293] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 01/17/2023] Open
Abstract
Retinal diseases such as age-related macular degeneration (AMD), retinopathy of prematurity (ROP), and diabetic retinopathy (DR) are the leading causes of visual impairment worldwide. There is a critical need to understand the structural and cellular components that play a vital role in the pathophysiology of retinal diseases. One potential component is the family of structural proteins called small leucine-rich proteoglycans (SLRPs). SLRPs are crucial in many fundamental biological processes involved in the maintenance of retinal homeostasis. They are present within the extracellular matrix (ECM) of connective and vascular tissues and contribute to tissue organization and modulation of cell growth. They play a vital role in cell–matrix interactions in many upstream signaling pathways involved in fibrillogenesis and angiogenesis. In this comprehensive review, we describe the expression patterns and function of SLRPs in the retina, including Biglycan and Decorin from class I; Fibromodulin, Lumican, and a Proline/arginine-rich end leucine-rich repeat protein (PRELP) from class II; Opticin and Osteoglycin/Mimecan from class III; and Chondroadherin (CHAD), Tsukushi and Nyctalopin from class IV.
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11
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An interplay of microglia and matrix metalloproteinase MMP9 under hypoxic stress regulates the opticin expression in retina. Sci Rep 2021; 11:7444. [PMID: 33811221 PMCID: PMC8018966 DOI: 10.1038/s41598-021-86302-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 03/12/2021] [Indexed: 02/07/2023] Open
Abstract
Inflammation plays a key role in the pathogenesis of retinal vascular diseases. We have shown earlier an increase in the activity of matrix metalloproteinases in the vitreous and tears of preterm born babies with retinopathy of prematurity (ROP) compared to those with no-ROP leading to a shift in the balance of angiogenic (vascular endothelial growth factor [VEGF], matrix metalloproteinase [MMPs], complement component [C3]) and anti-angiogenic (opticin, thrombospondin) in ROP eyes. We now confirmed that tear MMP levels in premature infants perfectly correlates with disease severity. Next, we demonstrated that a reduced opticin levels in ROP vitreous are regulated by MMPs secreted by activated microglia. Upon exposing the human microglia cell line (CHME3) to hypoxia, an increased expression of inflammatory proteins (MMP9, VEGF) was noticed while opticin reduced significantly (p = 0.005). Further, the reduced opticin’s expression by microglial cells under hypoxia could be rescued by inhibiting the MMP activity using doxycycline and EDTA. The inhibition of MMP activity altered the expression of other key signaling molecules under hypoxia. Our study clearly explains that increased activity of MMPs under hypoxia regulates the expression of opticin as seen in the vitreous humor of ROP and could serve as a potential target for ROP management.
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12
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Pouw AE, Greiner MA, Coussa RG, Jiao C, Han IC, Skeie JM, Fingert JH, Mullins RF, Sohn EH. Cell-Matrix Interactions in the Eye: From Cornea to Choroid. Cells 2021; 10:687. [PMID: 33804633 PMCID: PMC8003714 DOI: 10.3390/cells10030687] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/03/2021] [Accepted: 03/16/2021] [Indexed: 02/07/2023] Open
Abstract
The extracellular matrix (ECM) plays a crucial role in all parts of the eye, from maintaining clarity and hydration of the cornea and vitreous to regulating angiogenesis, intraocular pressure maintenance, and vascular signaling. This review focuses on the interactions of the ECM for homeostasis of normal physiologic functions of the cornea, vitreous, retina, retinal pigment epithelium, Bruch's membrane, and choroid as well as trabecular meshwork, optic nerve, conjunctiva and tenon's layer as it relates to glaucoma. A variety of pathways and key factors related to ECM in the eye are discussed, including but not limited to those related to transforming growth factor-β, vascular endothelial growth factor, basic-fibroblastic growth factor, connective tissue growth factor, matrix metalloproteinases (including MMP-2 and MMP-9, and MMP-14), collagen IV, fibronectin, elastin, canonical signaling, integrins, and endothelial morphogenesis consistent of cellular activation-tubulogenesis and cellular differentiation-stabilization. Alterations contributing to disease states such as wound healing, diabetes-related complications, Fuchs endothelial corneal dystrophy, angiogenesis, fibrosis, age-related macular degeneration, retinal detachment, and posteriorly inserted vitreous base are also reviewed.
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Affiliation(s)
- Andrew E. Pouw
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
- Institute for Vision Research, University of Iowa, Iowa City, IA 52242, USA
| | - Mark A. Greiner
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
- Institute for Vision Research, University of Iowa, Iowa City, IA 52242, USA
| | - Razek G. Coussa
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
- Institute for Vision Research, University of Iowa, Iowa City, IA 52242, USA
| | - Chunhua Jiao
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
- Institute for Vision Research, University of Iowa, Iowa City, IA 52242, USA
| | - Ian C. Han
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
- Institute for Vision Research, University of Iowa, Iowa City, IA 52242, USA
| | - Jessica M. Skeie
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
| | - John H. Fingert
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
- Institute for Vision Research, University of Iowa, Iowa City, IA 52242, USA
| | - Robert F. Mullins
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
- Institute for Vision Research, University of Iowa, Iowa City, IA 52242, USA
| | - Elliott H. Sohn
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA; (A.E.P.); (M.A.G.); (R.G.C.); (C.J.); (I.C.H.); (J.M.S.); (J.H.F.); (R.F.M.)
- Institute for Vision Research, University of Iowa, Iowa City, IA 52242, USA
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Novel Outcome Biomarkers Identified With Targeted Proteomic Analyses of Plasma From Critically Ill Coronavirus Disease 2019 Patients. Crit Care Explor 2020; 2:e0189. [PMID: 32904064 PMCID: PMC7449255 DOI: 10.1097/cce.0000000000000189] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Supplemental Digital Content is available in the text. Coronavirus disease 2019 patients admitted to the ICU have high mortality. The host response to coronavirus disease 2019 has only been partially elucidated, and prognostic biomarkers have not been identified. We performed targeted proteomics on critically ill coronavirus disease 2019 patients to better understand their pathophysiologic mediators and to identify potential outcome markers.
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14
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Xing Y, Li XK, Lu SD, Ma J. Regulation of opticin on bioactivity of retinal vascular endothelial cells cultured in collagen. Int J Ophthalmol 2020; 13:1202-1209. [PMID: 32821673 DOI: 10.18240/ijo.2020.08.05] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 04/29/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate the effects of collagen and opticin on the bioactivity of human retinal vascular endothelial cells (hRVECs), and explore its regulations by integrins and RhoA/ROCK1 signal pathway. METHODS hRVECs were cultured in collagen and treated by opticin, and cell-based bioactivity assays of cell proliferation, migration, and adhesion were performed. The expression of integrin α2, integrin β1, RhoA and ROCK1 were examined with real-time PCR and Western blotting. RESULTS Collagen could promote cell viability of proliferation and migration (all P<0.05), and enhance the mRNA expression of integrin α2, integrin β1, RhoA and ROCK1 (all P<0.05). Opticin could inhibit proliferation and migration ability of hRVECs cultured in collagen, and reduce the mRNA expression of integrin α2, integrin β1, RhoA and ROCK1 (all P<0.05). CONCLUSION Collagen and opticin can affect bioactivity of hRVECs, which may be regulated by α2-, β1-integrins and RhoA/ROCK1 signal pathway.
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Affiliation(s)
- Yue Xing
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Xue-Ke Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Si-Duo Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Jin Ma
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
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15
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Hansen U, Holmes DF, Bruckner P, Bishop PN. Analysis of opticin binding to collagen fibrils identifies a single binding site in the gap region and a high specificity towards thin heterotypic fibrils containing collagens II, and XI or V/XI. PLoS One 2020; 15:e0234672. [PMID: 32764753 PMCID: PMC7413481 DOI: 10.1371/journal.pone.0234672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/23/2020] [Indexed: 11/29/2022] Open
Abstract
Opticin is a class III member of the extracellular matrix small leucine-rich repeat protein/proteoglycan (SLRP) family found in vitreous humour and cartilage. It was first identified associated with the surface of vitreous collagen fibrils and several other SLRPs are also known to bind collagen fibrils and it some cases alter fibril morphology. The purpose of this study was to investigate the binding of opticin to the collagen II-containing fibrils found in vitreous and cartilage. Electron microscopic studies using gold labelling demonstrated that opticin binds vitreous and thin cartilage collagen fibrils specifically at a single site in the gap region of the collagen D-period corresponding to the e2 stain band; this is the first demonstration of the binding site of a class III SLRP on collagen fibrils. Opticin did not bind thick cartilage collagen fibrils from cartilage or tactoids formed in vitro from collagen II, but shows high specificity for thin, heterotypic collagen fibrils containing collagens II, and XI or V/XI. Vitreous collagen fibrils from opticin null and wild-type mice were compared and no difference in fibril morphology or diameter was observed. Similarly, in vitro fibrillogenesis experiments showed that opticin did not affect fibril formation. We propose that when opticin is bound to collagen fibrils, rather than influencing their morphology it instead hinders the binding of other molecules to the fibril surfaces and/or act as an intermediary bridge linking the collagen fibrils to other non-collagenous molecules.
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Affiliation(s)
- Uwe Hansen
- Department of Physiological Chemistry & Pathobiochemistry, University Hospital of Münster, Münster, Germany
- Institute of Musculoskeletal Medicine, University Hospital Münster, Münster, Germany
- * E-mail: (PNB); (UH)
| | - David F. Holmes
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Peter Bruckner
- Department of Physiological Chemistry & Pathobiochemistry, University Hospital of Münster, Münster, Germany
| | - Paul N. Bishop
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
- * E-mail: (PNB); (UH)
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16
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Del Amo EM, Griffiths JR, Klaska IP, Hoke J, White A, Aarons L, Cooper GJS, Bainbridge JWB, Bishop PN, Unwin RD. Intravitreal Pharmacokinetic Study of the Antiangiogenic Glycoprotein Opticin. Mol Pharm 2020; 17:2390-2397. [PMID: 32437164 PMCID: PMC7341526 DOI: 10.1021/acs.molpharmaceut.0c00151] [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] [Indexed: 11/30/2022]
Abstract
![]()
Opticin is an endogenous vitreous
glycoprotein that may have therapeutic
potential as it has been shown that supranormal concentrations suppress
preretinal neovascularization. Herein we investigated the pharmacokinetics
of opticin following intravitreal injection in rabbits. To measure
simultaneously concentrations of human and rabbit opticin, a selected
reaction monitoring mass spectrometry assay was developed. The mean
concentration of endogenous rabbit opticin in 7 uninjected eyes was
measured and found to be 19.2 nM or 0.62 μg/mL. When the vitreous
was separated by centrifugation into a supernatant and collagen-containing
pellet, 94% of the rabbit opticin was in the supernatant. Intravitreal
injection of human opticin (40 μg) into both eyes of rabbits
was followed by enucleation at 5, 24, and 72 h and 7, 14, and 28 days
postinjection (n = 6 at each time point) and measurement
of vitreous human and rabbit opticin concentrations in the supernatant
and collagen-containing pellet following centrifugation. The volume
of distribution of human opticin was calculated to be 3.31 mL, and
the vitreous half-life was 4.2 days. Assuming that rabbit and human
opticin are cleared from rabbit vitreous at the same rate, opticin
is secreted into the vitreous at a rate of 0.14 μg/day. We conclude
that intravitreally injected opticin has a vitreous half-life that
is similar to currently available antiangiogenic therapeutics. While
opticin was first identified bound to vitreous collagen fibrils, here
we demonstrate that >90% of endogenous opticin is not bound to
collagen.
Endogenous opticin is secreted by the nonpigmented ciliary epithelium
into the rabbit vitreous at a remarkably high rate, and the turnover
in vitreous is approximately 15% per day.
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Affiliation(s)
- Eva M Del Amo
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine & Health (FBMH), University of Manchester, Manchester M13 9PT, United Kingdom
| | - John R Griffiths
- Division of Cardiovascular Sciences, School of Medical Sciences, FBMH, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Izabela P Klaska
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
| | - Justin Hoke
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
| | - Anne White
- Division of Evolution & Genomic Sciences, School of Biological Sciences, FBMH, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Leon Aarons
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine & Health (FBMH), University of Manchester, Manchester M13 9PT, United Kingdom
| | - Garth J S Cooper
- Division of Cardiovascular Sciences, School of Medical Sciences, FBMH, University of Manchester, Manchester M13 9PT, United Kingdom
| | - James W B Bainbridge
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
| | - Paul N Bishop
- Division of Evolution & Genomic Sciences, School of Biological Sciences, FBMH, University of Manchester, Manchester M13 9PL, United Kingdom.,Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom
| | - Richard D Unwin
- Division of Cardiovascular Sciences, School of Medical Sciences, FBMH, University of Manchester, Manchester M13 9PT, United Kingdom.,Stoller Biomarker Discovery Centre and Division of Cancer Sciences, School of Medical Sciences, FBMH, University of Manchester, Manchester M13 9PL, United Kingdom
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17
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Paraoan L, Sharif U, Carlsson E, Supharattanasitthi W, Mahmud NM, Kamalden TA, Hiscott P, Jackson M, Grierson I. Secretory proteostasis of the retinal pigmented epithelium: Impairment links to age-related macular degeneration. Prog Retin Eye Res 2020; 79:100859. [PMID: 32278708 DOI: 10.1016/j.preteyeres.2020.100859] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 12/19/2022]
Abstract
Secretory proteostasis integrates protein synthesis, processing, folding and trafficking pathways that are essential for efficient cellular secretion. For the retinal pigment epithelium (RPE), secretory proteostasis is of vital importance for the maintenance of the structural and functional integrity of apical (photoreceptors) and basal (Bruch's membrane/choroidal blood supply) sides of the environment it resides in. This integrity is achieved through functions governed by RPE secreted proteins, which include extracellular matrix modelling/remodelling, angiogenesis and immune response modulation. Impaired RPE secretory proteostasis affects not only the extracellular environment, but leads to intracellular protein aggregation and ER-stress with subsequent cell death. Ample recent evidence implicates dysregulated proteostasis as a key factor in the development of age-related macular degeneration (AMD), the leading cause of blindness in the developed world, and research aiming to characterise the roles of various proteins implicated in AMD-associated dysregulated proteostasis unveiled unexpected facets of the mechanisms involved in degenerative pathogenesis. This review analyses cellular processes unveiled by the study of the top 200 transcripts most abundantly expressed by the RPE/choroid in the light of the specialised secretory nature of the RPE. Functional roles of these proteins and the mechanisms of their impaired secretion, due to age and genetic-related causes, are analysed in relation to AMD development. Understanding the importance of RPE secretory proteostasis in relation to maintaining retinal health and how it becomes impaired in disease is of paramount importance for the development and assessment of future therapeutic advancements involving gene and cell therapies.
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Affiliation(s)
- Luminita Paraoan
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.
| | - Umar Sharif
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Emil Carlsson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Wasu Supharattanasitthi
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom; Department of Physiology, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
| | - Nur Musfirah Mahmud
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Tengku Ain Kamalden
- Eye Research Centre, Department of Ophthalmology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Paul Hiscott
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Malcolm Jackson
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Ian Grierson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
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18
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Sebag J. Vitreous and Vision Degrading Myodesopsia. Prog Retin Eye Res 2020; 79:100847. [PMID: 32151758 DOI: 10.1016/j.preteyeres.2020.100847] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 12/16/2022]
Abstract
Macromolecules comprise only 2% of vitreous, yet are responsible for its gel state, transparency, and physiologic function(s) within the eye. Myopia and aging alter collagen and hyaluronan association causing concurrent gel liquefaction and fibrous degeneration. The resulting vitreous opacities and collapse of the vitreous body during posterior vitreous detachment are the most common causes for the visual phenomenon of vitreous floaters. Previously considered innocuous, the vitreous opacities that cause floaters sometimes impact vision by profoundly degrading contrast sensitivity function and impairing quality-of-life. While many people adapt to vitreous floaters, clinically significant cases can be diagnosed with Vision Degrading Myodesopsia based upon echographic assessment of vitreous structure and by measuring contrast sensitivity function. Perhaps due to the ubiquity of floaters, the medical profession has to date largely ignored the plight of those with Vision Degrading Myodesopsia. Improved diagnostics will enable better disease staging and more accurate identification of severe cases that merit therapy. YAG laser treatments may occasionally be slightly effective, but vitrectomy is currently the definitive cure. Future developments will usher in more informative diagnostic approaches as well as safer and more effective therapeutic strategies. Improved laser treatments, new pharmacotherapies, and possibly non-invasive optical corrections are exciting new approaches to pursue. Ultimately, enhanced understanding of the underlying pathogenesis of Vision Degrading Myodesopsia should result in prevention, the ultimate goal of modern Medicine.
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Affiliation(s)
- J Sebag
- VMR Institute for Vitreous Macula Retina, Huntington Beach, CA, USA; Doheny Eye Institute, Pasadena, CA, USA; Department of Ophthalmology, Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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19
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Zappia J, Joiret M, Sanchez C, Lambert C, Geris L, Muller M, Henrotin Y. From Translation to Protein Degradation as Mechanisms for Regulating Biological Functions: A Review on the SLRP Family in Skeletal Tissues. Biomolecules 2020; 10:biom10010080. [PMID: 31947880 PMCID: PMC7023458 DOI: 10.3390/biom10010080] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 12/19/2019] [Accepted: 12/26/2019] [Indexed: 12/27/2022] Open
Abstract
The extracellular matrix can trigger cellular responses through its composition and structure. Major extracellular matrix components are the proteoglycans, which are composed of a core protein associated with glycosaminoglycans, among which the small leucine-rich proteoglycans (SLRPs) are the largest family. This review highlights how the codon usage pattern can be used to modulate cellular response and discusses the biological impact of post-translational events on SLRPs, including the substitution of glycosaminoglycan moieties, glycosylation, and degradation. These modifications are listed, and their impacts on the biological activities and structural properties of SLRPs are described. We narrowed the topic to skeletal tissues undergoing dynamic remodeling.
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Affiliation(s)
- Jérémie Zappia
- Bone and Cartilage Research Unit, Arthropôle Liège, Center for Interdisciplinary research on Medicines (CIRM) Liège, Liège University, Institute of Pathology, CHU Sart-Tilman, 4000 Liège, Belgium; (J.Z.); (C.S.); (C.L.)
| | - Marc Joiret
- Biomechanics Research Unit, B34 GIGA-R, In Silico Medicine, Liège University, CHU Sart-Tilman, 4000 Liège, Belgium; (M.J.); (L.G.)
| | - Christelle Sanchez
- Bone and Cartilage Research Unit, Arthropôle Liège, Center for Interdisciplinary research on Medicines (CIRM) Liège, Liège University, Institute of Pathology, CHU Sart-Tilman, 4000 Liège, Belgium; (J.Z.); (C.S.); (C.L.)
| | - Cécile Lambert
- Bone and Cartilage Research Unit, Arthropôle Liège, Center for Interdisciplinary research on Medicines (CIRM) Liège, Liège University, Institute of Pathology, CHU Sart-Tilman, 4000 Liège, Belgium; (J.Z.); (C.S.); (C.L.)
| | - Liesbet Geris
- Biomechanics Research Unit, B34 GIGA-R, In Silico Medicine, Liège University, CHU Sart-Tilman, 4000 Liège, Belgium; (M.J.); (L.G.)
| | - Marc Muller
- Laboratory for Organogenesis and Regeneration (LOR), GIGA-Research, Liège University, Avenue de l’Hôpital, B-4000 Liège, Belgium;
| | - Yves Henrotin
- Bone and Cartilage Research Unit, Arthropôle Liège, Center for Interdisciplinary research on Medicines (CIRM) Liège, Liège University, Institute of Pathology, CHU Sart-Tilman, 4000 Liège, Belgium; (J.Z.); (C.S.); (C.L.)
- Physical therapy and Rehabilitation department, Princess Paola Hospital, Vivalia, B-6900 Marche-en-Famenne, Belgium
- Artialis SA, GIGA Tower, Level 3, CHU Sart-Tilman, 4000 Liège, Belgium
- Correspondence: ; Tel.: +32-4-3665937
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20
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Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy. Sci Rep 2019; 9:7608. [PMID: 31110225 PMCID: PMC6527583 DOI: 10.1038/s41598-019-44031-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/07/2019] [Indexed: 02/07/2023] Open
Abstract
CAPN5 Neovascular Inflammatory Vitreoretinopathy (CAPN5-NIV; OMIM 193235) is a poorly-understood rare, progressive inflammatory intraocular disease with limited therapeutic options. To profile disease effector proteins in CAPN5-NIV patient vitreous, liquid vitreous biopsies were collected from two groups: eyes from control subjects (n = 4) with idiopathic macular holes (IMH) and eyes from test subjects (n = 12) with different stages of CAPN5-NIV. Samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Protein expression changes were evaluated by principal component analysis, 1-way ANOVA (significant p-value < 0.05), hierarchical clustering, gene ontology, and pathway representation. There were 216 differentially-expressed proteins (between CAPN5-NIV and control vitreous), including those unique to and abundant in each clinical stage. Gene ontology analysis revealed decreased synaptic signaling proteins in CAPN5-NIV vitreous compared to controls. Pathway analysis revealed that inflammatory mediators of the acute phase response and the complement cascade were highly-represented. The CAPN5-NIV vitreous proteome displayed characteristic enrichment of proteins and pathways previously-associated with non-infectious posterior uveitis, rhegmatogenous retinal detachment (RRD), age-related macular degeneration (AMD), proliferative diabetic retinopathy (PDR), and proliferative vitreoretinopathy (PVR). This study expands our knowledge of affected molecular pathways in CAPN5-NIV using unbiased, shotgun proteomic analysis rather than targeted detection platforms. The high-levels and representation of acute phase response proteins suggests a functional role for the innate immune system in CAPN5-NIV pathogenesis.
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21
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Rämisch S, Pramhed A, Tillgren V, Aspberg A, Logan DT. Crystal structure of human chondroadherin: solving a difficult molecular-replacement problem usingde novomodels. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2017; 73:53-63. [DOI: 10.1107/s205979831601980x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 12/12/2016] [Indexed: 02/08/2023]
Abstract
Chondroadherin (CHAD) is a cartilage matrix protein that mediates the adhesion of isolated chondrocytes. Its protein core is composed of 11 leucine-rich repeats (LRR) flanked by cysteine-rich domains. CHAD makes important interactions with collagen as well as with cell-surface heparin sulfate proteoglycans and α2β1integrins. The integrin-binding site is located in a region of hitherto unknown structure at the C-terminal end of CHAD. Peptides based on the C-terminal human CHAD (hCHAD) sequence have shown therapeutic potential for treating osteoporosis. This article describes a still-unconventional structure solution by phasing withde novomodels, the first of a β-rich protein. Structure determination of hCHAD using traditional, though nonsystematic, molecular replacement was unsuccessful in the hands of the authors, possibly owing to a combination of low sequence identity to other LRR proteins, four copies in the asymmetric unit and weak translational pseudosymmetry. However, it was possible to solve the structure by generating a large number ofde novomodels for the central LRR domain usingRosettaand multiple parallel molecular-replacement attempts usingAMPLE. The hCHAD structure reveals an ordered C-terminal domain belonging to the LRRCT fold, with the integrin-binding motif (WLEAK) being part of a regular α-helix, and suggests ways in which experimental therapeutic peptides can be improved. The crystal structure itself and docking simulations further support that hCHAD dimers form in a similar manner to other matrix LRR proteins.
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Wu QH, Ma Y, Ruan CC, Yang Y, Liu XH, Ge Q, Kong LR, Zhang JW, Yan C, Gao PJ. Loss of osteoglycin promotes angiogenesis in limb ischaemia mouse models via modulation of vascular endothelial growth factor and vascular endothelial growth factor receptor 2 signalling pathway. Cardiovasc Res 2016; 113:70-80. [DOI: 10.1093/cvr/cvw220] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 08/29/2016] [Accepted: 09/21/2016] [Indexed: 01/22/2023] Open
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The role of extracellular matrix in retinal vascular development and preretinal neovascularization. Exp Eye Res 2015; 133:30-6. [PMID: 25819452 DOI: 10.1016/j.exer.2014.10.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 10/14/2014] [Accepted: 10/29/2014] [Indexed: 12/17/2022]
Abstract
Extracellular matrix (ECM) plays a central role in angiogenesis. ECM degrading enzymes breakdown the pre-existing vascular basement membrane at an early stage of angiogenesis and subsequently degrade stromal ECM as the new vessels invade into tissues. Conversely certain ECM components including collagen, fibronectin or fibrin are required for endothelial cell migration and tube morphogenesis. As the new vessels form they lay down a basement membrane that surrounds the endothelial tubes and is essential for their stability. In the rodent eye the transient expression of fibronectin and matricellular proteins plays a key role in retinal vascular development. In pathological retinal angiogenesis, such as in proliferative diabetic retinopathy, preretinal neovascularization occurs where new blood vessels invade the cortical vitreous gel and these blood vessels require vitreous collagen for their growth. The vitreous is normally anti-angiogenic and contains endogenous ECM inhibitors of angiogenesis including opticin and thombospondins, and ECM fragments such as endostatin. In preretinal neovascularization, the combined anti-angiogenic effects of these molecules are overcome by an excess of growth factors such as vascular endothelial growth factor-A, and new vessels grow into the vitreous with potentially blinding sequelae.
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24
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Role of tyrosine-sulfated proteins in retinal structure and function. Exp Eye Res 2015; 133:126-31. [PMID: 25819460 DOI: 10.1016/j.exer.2014.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 06/30/2014] [Accepted: 07/08/2014] [Indexed: 01/13/2023]
Abstract
The extracellular matrix (ECM) plays a significant role in cellular and retinal health. The study of retinal tyrosine-sulfated proteins is an important first step toward understanding the role of ECM in retinal health and diseases. These secreted proteins are members of the retinal ECM. Tyrosine sulfation was shown to be necessary for the development of proper retinal structure and function. The importance of tyrosine sulfation is further demonstrated by the evolutionary presence of tyrosylprotein sulfotransferases, enzymes that catalyze proteins' tyrosine sulfation, and the compensatory abilities of these enzymes. Research has identified four tyrosine-sulfated retinal proteins: fibulin 2, vitronectin, complement factor H (CFH), and opticin. Vitronectin and CFH regulate the activation of the complement system and are involved in the etiology of some cases of age-related macular degeneration. Analysis of the role of tyrosine sulfation in fibulin function showed that sulfation influences the protein's ability to regulate growth and migration. Although opticin was recently shown to exhibit anti-angiogenic properties, it is not yet determined what role sulfation plays in that function. Future studies focusing on identifying all of the tyrosine-sulfated retinal proteins would be instrumental in determining the impact of sulfation on retinal protein function in retinal homeostasis and diseases.
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25
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Iozzo RV, Schaefer L. Proteoglycan form and function: A comprehensive nomenclature of proteoglycans. Matrix Biol 2015; 42:11-55. [PMID: 25701227 PMCID: PMC4859157 DOI: 10.1016/j.matbio.2015.02.003] [Citation(s) in RCA: 772] [Impact Index Per Article: 85.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 02/09/2015] [Indexed: 02/07/2023]
Abstract
We provide a comprehensive classification of the proteoglycan gene families and respective protein cores. This updated nomenclature is based on three criteria: Cellular and subcellular location, overall gene/protein homology, and the utilization of specific protein modules within their respective protein cores. These three signatures were utilized to design four major classes of proteoglycans with distinct forms and functions: the intracellular, cell-surface, pericellular and extracellular proteoglycans. The proposed nomenclature encompasses forty-three distinct proteoglycan-encoding genes and many alternatively-spliced variants. The biological functions of these four proteoglycan families are critically assessed in development, cancer and angiogenesis, and in various acquired and genetic diseases where their expression is aberrant.
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Affiliation(s)
- Renato V Iozzo
- Department of Pathology, Anatomy and Cell Biology and the Cancer Cell Biology and Signaling Program, Kimmel Cancer Center, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - Liliana Schaefer
- Pharmazentrum Frankfurt/ZAFES, Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität Frankfurt am Main, Frankfurt am Main, Germany.
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Kanan Y, Siefert JC, Kinter M, Al-Ubaidi MR. Complement factor H, vitronectin, and opticin are tyrosine-sulfated proteins of the retinal pigment epithelium. PLoS One 2014; 9:e105409. [PMID: 25136834 PMCID: PMC4138151 DOI: 10.1371/journal.pone.0105409] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 07/23/2014] [Indexed: 01/09/2023] Open
Abstract
Lack of tyrosine sulfation of ocular proteins results in disorganized photoreceptor structure and drastically reduced visual function, demonstrating the importance of this post-translational modification to vision. To understand the role that tyrosine sulfation plays in the function of ocular proteins, we identified some tyrosine-sulfated proteins in the retinal pigment epithelium using two independent methods, immuno-affinity column purification with an anti-sulfotyrosine specific antibody and computer-based sequence analysis of retinal pigment epithelium secretome by means of the prediction program Sulfinator. Radioactive labeling followed by thin layer electrophoresis revealed that three proteins, vitronectin, opticin, and complement factor H (CFH), were post-translationally modified by tyrosine sulfation. The identification of vitronectin and CFH as tyrosine-sulfated proteins is significant, since both are deposited in drusen in the eyes of patients with age-related macular degeneration (AMD). Furthermore, mutations in CFH have been determined to be a major risk factor in the development of AMD. Future studies that seek to understand the role of CFH in the development of AMD should take into account the role that tyrosine sulfation plays in the interaction of this protein with its partners, and examine whether modulating sulfation provides a potential therapeutic target.
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Affiliation(s)
- Yogita Kanan
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Joseph C. Siefert
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Michael Kinter
- Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Muayyad R. Al-Ubaidi
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
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Bosutti A, Qi J, Pennucci R, Bolton D, Matou S, Ali K, Tsai LH, Krupinski J, Petcu EB, Montaner J, Al Baradie R, Caccuri F, Caruso A, Alessandri G, Kumar S, Rodriguez C, Martinez-Gonzalez J, Slevin M. Targeting p35/Cdk5 signalling via CIP-peptide promotes angiogenesis in hypoxia. PLoS One 2013; 8:e75538. [PMID: 24098701 PMCID: PMC3787057 DOI: 10.1371/journal.pone.0075538] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 08/19/2013] [Indexed: 01/19/2023] Open
Abstract
Cyclin-dependent kinase-5 (Cdk5) is over-expressed in both neurons and microvessels in hypoxic regions of stroke tissue and has a significant pathological role following hyper-phosphorylation leading to calpain-induced cell death. Here, we have identified a critical role of Cdk5 in cytoskeleton/focal dynamics, wherein its activator, p35, redistributes along actin microfilaments of spreading cells co-localising with p(Tyr15)Cdk5, talin/integrin beta-1 at the lamellipodia in polarising cells. Cdk5 inhibition (roscovitine) resulted in actin-cytoskeleton disorganisation, prevention of protein co-localization and inhibition of movement. Cells expressing Cdk5 (D144N) kinase mutant, were unable to spread, migrate and form tube-like structures or sprouts, while Cdk5 wild-type over-expression showed enhanced motility and angiogenesis in vitro, which was maintained during hypoxia. Gene microarray studies demonstrated myocyte enhancer factor (MEF2C) as a substrate for Cdk5-mediated angiogenesis in vitro. MEF2C showed nuclear co-immunoprecipitation with Cdk5 and almost complete inhibition of differentiation and sprout formation following siRNA knock-down. In hypoxia, insertion of Cdk5/p25-inhibitory peptide (CIP) vector preserved and enhanced in vitro angiogenesis. These results demonstrate the existence of critical and complementary signalling pathways through Cdk5 and p35, and through which coordination is a required factor for successful angiogenesis in sustained hypoxic condition.
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Affiliation(s)
- Alessandra Bosutti
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - Jie Qi
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - Roberta Pennucci
- Cell Adhesion Unit, Department of Neuroscience Dibit-Istituto Scientifico San Raffaele, Milano, Italy
| | | | - Sabine Matou
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - Kamela Ali
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - Li-Huei Tsai
- Howard Hughes Medical Institute, Massachusetts Institute of Technology Picower Institute for Learning and Memory, Cambridge, Massachusetts, United States of America
- Stanley Centre for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, United States of America
| | - Jerzy Krupinski
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
- Hospital Universitari Mútua de Terrassa, Department of Neurology, Barcelona, Spain
| | - Eugene B. Petcu
- Griffith University School of Medicine, Gold Coast Campus, Griffith University, Southport, Australia
| | - Joan Montaner
- Neurovascular Research Laboratory, Vall De’Hebron University Hospital, Barcelona, Spain
| | - Raid Al Baradie
- College of Applied Medical Science, Almajmaah University, Almajmaah, Kingdom of Saudi Arabia
| | - Francesca Caccuri
- University of Brescia, Section of Microbiology, Department of Experimental and Applied Medicine, Medical School, Brescia, Italy
| | - Arnaldo Caruso
- University of Brescia, Section of Microbiology, Department of Experimental and Applied Medicine, Medical School, Brescia, Italy
| | - Giulio Alessandri
- Fondazione Istituto di Ricovero e Cura Carattere Scientifico Neurological Institute "Carlo Besta", Cellular Neurobiology Laboratory, Department of Cerebrovascular Diseases, Milan, Italy
| | - Shant Kumar
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
- Department of Pathological Sciences, Manchester University and Christie Hospital, Manchester, United Kingdom
| | - Cristina Rodriguez
- Centro de Investigacion Cardiovascular, Hospital de la Santa Creu i Sant, Pau, Barcelona, Spain
| | - Jose Martinez-Gonzalez
- Centro de Investigacion Cardiovascular, Hospital de la Santa Creu i Sant, Pau, Barcelona, Spain
| | - Mark Slevin
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
- Griffith University School of Medicine, Gold Coast Campus, Griffith University, Southport, Australia
- *E-mail:
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Mikaelsson E, Osterborg A, Tahmasebi Fard Z, Mahmoudi A, Mahmoudian J, Jeddi-Tehrani M, Akhondi M, Shokri F, Bishop PN, Rabbani H, Mellstedt H. Opticin, a small leucine-rich proteoglycan, is uniquely expressed and translocated to the nucleus of chronic lymphocytic leukemia cells. Exp Hematol Oncol 2013; 2:23. [PMID: 24499526 PMCID: PMC3766095 DOI: 10.1186/2162-3619-2-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 08/21/2013] [Indexed: 11/11/2022] Open
Abstract
Background Opticin (OPTC) is a member of the small leucine-rich proteoglycan (SLRP) family and is localized particularly in certain extracellular matrices. We have previously reported the unique expression of another SLRP, fibromodulin (FMOD) in the leukemic cells of patients with chronic lymphocytic leukemia (CLL). OPTC is located in the same region as FMOD on chromosome 1 (1q32.1). Cluster up-regulation of genes may be observed in malignancies and the aim of the present study was to analyze the expression of OPTC in CLL cells. Methods The expression of OPTC was tested by RT-PCR and realtime qPCR in PBMC from CLL patients, other hematological malignancies and healthy controls. The presence of OPTC protein, and its subcellular localization, was investigated using fractionation methods where the obtained lysate fractions were analyzed by Western blotting. Deglycosylation experiments were performed to investigate the glycosylation status of the CLL OPTC. Results OPTC was expressed at the gene level in all patients with CLL (n = 90) and in 2/8 patients with mantle cell lymphoma (MCL) but not in blood mononuclear cells of healthy control donors (n = 20) or in tumor samples from nine other types of hematological malignancies. OPTC was detected by Western blot in all CLL samples analyzed (n = 30) but not in normal leukocytes (n = 10). Further analysis revealed a CLL-unique unglycosylated 37 kDa core protein that was found to be located preferentially in the cell nucleus and endoplasmic reticulum (ER) of the CLL cells. Conclusions A 37 kDa unglycosylated OPTC protein was detected in ER and in the nucleus of CLL cells and not in healthy control donors. The function of this OPTC core protein remains unclear but its CLL-specific expression and subcellular localization warrants further investigations in the pathobiology of CLL.
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Affiliation(s)
- Eva Mikaelsson
- Immune and Gene Therapy Lab, CCK, Department of Oncology-Pathology, Karolinska Institute, Stockholm, Sweden.
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Characterization of opticin digestion by proteases involved in osteoarthritis development. Joint Bone Spine 2013; 81:137-41. [PMID: 23845380 DOI: 10.1016/j.jbspin.2013.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 05/23/2013] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Opticin is a class III member of the small leucine-rich repeat proteoglycan (SLRP) family, produced in articular joint tissues. In normal and osteoarthritic (OA) cartilage, opticin is degraded. This study aimed to assess whether human cartilage opticin is degraded by the main proteases involved in OA pathophysiology, and to determine the protease cleavage sites of this SLRP. METHODS We analyzed the proteolytic activity of matrix metalloproteinases (MMPs)-1, -2, -3, -7, -8 and -9, and ADAMTS-4 and -5 on proteoglycan extracts from normal and moderately fibrillated OA human cartilage, and on recombinant human opticin. Opticin degradation was analyzed by Western blotting and cleavage sites were determined by sequence analysis. RESULTS All eight proteases digested opticin from proteoglycan extracts from both normal and OA samples, as well as recombinant human opticin, MMP-2 and MMP-7 are the proteases that degrade recombinant human opticin most efficiently. The opticin cleavage site determined for these MMPs was between the glycosylation and leucine-rich repeat domains. MMP-7 had two additional digestion sites near the N-terminal end of opticin. CONCLUSION Opticin is a substrate for several MMPs and aggrecanases involved during OA cartilage degradation, and seems to be a preferential substrate for MMP-7. The role of opticin in cartilage degeneration could be related to decreased levels of intact opticin, followed by its proteolytic degradation, which in turn may stimulate some of the modifications observed in the OA cartilage, such as neovascularisation and changes in the extracellular matrix.
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Hoffman MJ, Flister MJ, Nunez L, Xiao B, Greene AS, Jacob HJ, Moreno C. Female-specific hypertension loci on rat chromosome 13. Hypertension 2013; 62:557-63. [PMID: 23817491 DOI: 10.1161/hypertensionaha.113.01708] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A 3.7-Mb region of rat chromosome 13 (45.2-49.0 Mb) affects blood pressure (BP) in females only, indicating the presence of sex-specific BP loci in close proximity to the Renin locus. In the present study, we used a series of Dahl salt-sensitive/Mcwi-13 Brown Norway congenic rat strains to further resolve BP loci within this region. We identified 3 BP loci affecting female rats only, of which the 2 smaller loci (line9BP3 and line9BP4) were functionally characterized by sequence and expression analysis. Compared with SS (SS/HsdMcwiCrl), the presence of a 591-kb region of BN (BN/NHsdMcwi) chromosome 13 (line9BP3) significantly lowered BP by 21 mm Hg on an 8% NaCl diet (153 ± 7 versus 174 ± 5 mm Hg; P<0.001). Unexpectedly, the addition of 23 kb of Brown Norway chromosome 13 (line9BP4) completely erased the female-specific BP protection on 8% NaCl diet, suggesting that BN hypertensive allele(s) reside in this region. The congenic interval of the protective line 9F strain contains 3 genes (Optc, Prelp, and Fmod), and the hypertensive line 9E contains 1 additional gene (Btg2). Sequence analysis of the 2 BP loci revealed a total of 282 intergenic variants, with no coding variants. Analysis of gene expression by quantitative real-time polymerase chain reaction revealed strain- and sex-specific differences in Prelp, Fmod, and Btg2 expression, implicating these as novel candidate genes for female-specific hypertension.
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Affiliation(s)
- Matthew J Hoffman
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI, USA
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Byron A, Humphries JD, Humphries MJ. Defining the extracellular matrix using proteomics. Int J Exp Pathol 2013; 94:75-92. [PMID: 23419153 DOI: 10.1111/iep.12011] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 09/13/2012] [Accepted: 11/16/2012] [Indexed: 12/11/2022] Open
Abstract
The cell microenvironment has a profound influence on the behaviour, growth and survival of cells. The extracellular matrix (ECM) provides not only mechanical and structural support to cells and tissues but also binds soluble ligands and transmembrane receptors to provide spatial coordination of signalling processes. The ability of cells to sense the chemical, mechanical and topographical features of the ECM enables them to integrate complex, multiparametric information into a coherent response to the surrounding microenvironment. Consequently, dysregulation or mutation of ECM components results in a broad range of pathological conditions. Characterization of the composition of ECM derived from various cells has begun to reveal insights into ECM structure and function, and mechanisms of disease. Proteomic methodologies permit the global analysis of subcellular systems, but extracellular and transmembrane proteins present analytical difficulties to proteomic strategies owing to the particular biochemical properties of these molecules. Here, we review advances in proteomic approaches that have been applied to furthering our understanding of the ECM microenvironment. We survey recent studies that have addressed challenges in the analysis of ECM and discuss major outcomes in the context of health and disease. In addition, we summarize efforts to progress towards a systems-level understanding of ECM biology.
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Affiliation(s)
- Adam Byron
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, UK
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Keenan TDL, Clark SJ, Unwin RD, Ridge LA, Day AJ, Bishop PN. Mapping the differential distribution of proteoglycan core proteins in the adult human retina, choroid, and sclera. Invest Ophthalmol Vis Sci 2012; 53:7528-38. [PMID: 23074202 DOI: 10.1167/iovs.12-10797] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE To examine the presence and distribution of proteoglycan (PG) core proteins in the adult human retina, choroid, and sclera. METHODS Postmortem human eye tissue was dissected into Bruch's membrane/choroid complex, isolated Bruch's membrane, or neurosensory retina. PGs were extracted and partially purified by anion exchange chromatography. Trypsinized peptides were analyzed by tandem mass spectrometry and PG core proteins identified by database search. The distribution of PGs was examined by immunofluorescence microscopy on human macular tissue sections. RESULTS The basement membrane PGs perlecan, agrin, and collagen-XVIII were identified in the human retina, and were present in the internal limiting membrane, blood vessel walls, and Bruch's membrane. The hyalectans versican and aggrecan were also detected. Versican was identified in Bruch's membrane, while aggrecan was distributed throughout the retina, choroid, and sclera. The cartilage link protein HAPLN1 was abundant in the interphotoreceptor matrix and sclera, while HAPLN4 (brain link protein 2) was found throughout the retina and choroid. The small leucine-rich repeat PG (SLRP) family members biglycan, decorin, fibromodulin, lumican, mimecan, opticin, and prolargin were present, with different patterns of distribution in the retina, choroid, and sclera. CONCLUSIONS A combination of proteomics and immunohistochemistry approaches has provided for the first time a comprehensive analysis of the presence and distribution of PG core proteins throughout the human retina, choroid, and sclera. This complements our knowledge of glycosaminoglycan chain distribution in the human eye, and has important implications for understanding the structure and functional regulation of the eye in health and disease.
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Affiliation(s)
- Tiarnan D L Keenan
- Centre for Ophthalmology and Vision Research, Institute of Human Development, Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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