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Kaur S, Roberts DD. Why do humans need thrombospondin-1? J Cell Commun Signal 2023; 17:485-493. [PMID: 36689135 PMCID: PMC10409698 DOI: 10.1007/s12079-023-00722-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/07/2023] [Indexed: 01/24/2023] Open
Abstract
Matricellular proteins comprise several families of secreted proteins that function in higher animals at the interface between cells and their surrounding extracellular matrix. Targeted gene disruptions that result in loss of viability in mice have revealed critical roles for several matricellular proteins in murine embryonic development, including two members of the cellular communication network (CCN) gene family. In contrast, mice lacking single or multiple members of the thrombospondin (THBS) gene family remain viable and fertile. The frequency of loss of function mutants, identified using human deep exome sequencing data, provided evidence that some of the essential genes in mice, including Ccn1, are also essential genes in humans. However, a deficit in loss of function mutants in humans indicated that THBS1 is also highly loss-intolerant. In addition to roles in embryonic development or adult reproduction, genes may be loss-intolerant in humans because their function is needed to survive environmental stresses that are encountered between birth and reproduction. Laboratory mice live in a protected environment that lacks the exposures to pathogens and injury that humans routinely face. However, subjecting Thbs1-/- mice to defined stresses has provided valuable insights into functions of thrombospondin-1 that could account for the loss-intolerance of THBS1 in humans. Stress response models using transgenic mice have identified protective functions of thrombospondin-1 in the cardiovascular system (red) and immune defenses (blue) that could account for its intolerance to loss of function mutants in humans.
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Affiliation(s)
- Sukhbir Kaur
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 10 Room 2S235, 10 Center Dr, Bethesda, MD, 20892-1500, USA
| | - David D Roberts
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 10 Room 2S235, 10 Center Dr, Bethesda, MD, 20892-1500, USA.
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Forbes T, Pauza AG, Adams JC. In the balance: how do thrombospondins contribute to the cellular pathophysiology of cardiovascular disease? Am J Physiol Cell Physiol 2021; 321:C826-C845. [PMID: 34495764 DOI: 10.1152/ajpcell.00251.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Thrombospondins (TSPs) are multidomain, secreted proteins that associate with cell surfaces and extracellular matrix. In mammals, there is a large body of data on functional roles of various TSP family members in cardiovascular disease (CVD), including stroke, cardiac remodeling and fibrosis, atherosclerosis, and aortic aneurysms. Coding single nucleotide polymorphisms (SNPs) of TSP1 or TSP4 are also associated with increased risk of several forms of CVD. Whereas interactions and functional effects of TSPs on a variety of cell types have been studied extensively, the molecular and cellular basis for the differential effects of the SNPs remains under investigation. Here, we provide an integrative review on TSPs, their roles in CVD and cardiovascular cell physiology, and known properties and mechanisms of TSP SNPs relevant to CVD. In considering recent expansions to knowledge of the fundamental cellular roles and mechanisms of TSPs, as well as the effects of wild-type and variant TSPs on cells of the cardiovascular system, we aim to highlight knowledge gaps and areas for future research or of translational potential.
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Affiliation(s)
- Tessa Forbes
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Audrys G Pauza
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Josephine C Adams
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
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Kaur S, Roberts DD. Differential intolerance to loss of function and missense mutations in genes that encode human matricellular proteins. J Cell Commun Signal 2021; 15:93-105. [PMID: 33415696 PMCID: PMC7904989 DOI: 10.1007/s12079-020-00598-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/24/2020] [Indexed: 12/11/2022] Open
Abstract
Targeted gene disruption in mice has provided valuable insights into the functions of matricellular proteins. Apart from missense and loss of function mutations that have been associated with inherited diseases, however, their functions in humans remain unclear. The availability of deep exome sequencing data from over 140,000 individuals in the Genome Aggregation Database provided an opportunity to examine intolerance to loss of function and missense mutations in human matricellular genes. The probability of loss-of-function intolerance (pLI) differed widely within members of the thrombospondin, CYR61/CTGF/NOV (CCN), tenascin, small integrin-binding ligand N-linked glycoproteins (SIBLING), and secreted protein, acidic and rich in cysteine (SPARC) gene families. Notably, pLI values in humans had limited correlation with viability of the corresponding homozygous null mice. Among the thrombospondins, only THBS1 was highly loss-intolerant (pLI = 1). In contrast, Thbs1 is not essential for viability in mice. Several known thrombospondin-1 receptors were similarly loss-intolerant, although thrombospondin-1 is not the exclusive ligand for some of these receptors. The frequencies of missense mutations in THBS1 and the gene encoding its signaling receptor CD47 indicated conservation of some residues implicated in specific receptor binding. Deficits in missense mutations were also observed for other thrombospondin genes and for SPARC, SPOCK1, SPOCK2, TNR, and DSPP. The intolerance of THBS1 to loss of function in humans and elevated pLI values for THBS2, SPARC, SPOCK1, TNR, and CCN1 support important functions for these matricellular protein genes in humans, some of which may relate to functions in reproduction or responding to environmental stresses.
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Affiliation(s)
- Sukhbir Kaur
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Building 10 Room 2S235, 10 Center Drive MSC1500, Bethesda, MD, 20892-1500, USA.
| | - David D Roberts
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Building 10 Room 2S235, 10 Center Drive MSC1500, Bethesda, MD, 20892-1500, USA.
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4
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Thrombospondins: A Role in Cardiovascular Disease. Int J Mol Sci 2017; 18:ijms18071540. [PMID: 28714932 PMCID: PMC5536028 DOI: 10.3390/ijms18071540] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 07/05/2017] [Accepted: 07/13/2017] [Indexed: 12/16/2022] Open
Abstract
Thrombospondins (TSPs) represent extracellular matrix (ECM) proteins belonging to the TSP family that comprises five members. All TSPs have a complex multidomain structure that permits the interaction with various partners including other ECM proteins, cytokines, receptors, growth factors, etc. Among TSPs, TSP1, TSP2, and TSP4 are the most studied and functionally tested. TSP1 possesses anti-angiogenic activity and is able to activate transforming growth factor (TGF)-β, a potent profibrotic and anti-inflammatory factor. Both TSP2 and TSP4 are implicated in the control of ECM composition in hypertrophic hearts. TSP1, TSP2, and TSP4 also influence cardiac remodeling by affecting collagen production, activity of matrix metalloproteinases and TGF-β signaling, myofibroblast differentiation, cardiomyocyte apoptosis, and stretch-mediated enhancement of myocardial contraction. The development and evaluation of TSP-deficient animal models provided an option to assess the contribution of TSPs to cardiovascular pathology such as (myocardial infarction) MI, cardiac hypertrophy, heart failure, atherosclerosis, and aortic valve stenosis. Targeting of TSPs has a significant therapeutic value for treatment of cardiovascular disease. The activation of cardiac TSP signaling in stress and pressure overload may be therefore beneficial.
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Chandran S, Watkins J, Abdul-Aziz A, Shafat M, Calvert PA, Bowles KM, Flather MD, Rushworth SA, Ryding AD. Inflammatory Differences in Plaque Erosion and Rupture in Patients With ST-Segment Elevation Myocardial Infarction. J Am Heart Assoc 2017; 6:JAHA.117.005868. [PMID: 28468787 PMCID: PMC5524113 DOI: 10.1161/jaha.117.005868] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Background Plaque erosion causes 30% of ST‐segment elevation myocardial infarctions, but the underlying cause is unknown. Inflammatory infiltrates are less abundant in erosion compared with rupture in autopsy studies. We hypothesized that erosion and rupture are associated with significant differences in intracoronary cytokines in vivo. Methods and Results Forty ST‐segment elevation myocardial infarction patients with <6 hours of chest pain were classified as ruptured fibrous cap (RFC) or intact fibrous cap (IFC) using optical coherence tomography. Plasma samples from the infarct‐related artery and a peripheral artery were analyzed for expression of 102 cytokines using arrays; results were confirmed with ELISA. Thrombectomy samples were analyzed for differential mRNA expression using quantitative real‐time polymerase chain reaction. Twenty‐three lesions were classified as RFC (58%), 15 as IFC (38%), and 2 were undefined (4%). In addition, 12% (12 of 102) of cytokines were differentially expressed in both coronary and peripheral plasma. I‐TAC was preferentially expressed in RFC (significance analysis of microarrays adjusted P<0.001; ELISA IFC 10.2 versus RFC 10.8 log2 pg/mL; P=0.042). IFC was associated with preferential expression of epidermal growth factor (significance analysis of microarrays adjusted P<0.001; ELISA IFC 7.42 versus RFC 6.63 log2 pg/mL, P=0.036) and thrombospondin 1 (significance analysis of microarrays adjusted P=0.03; ELISA IFC 10.4 versus RFC 8.65 log2 ng/mL, P=0.0041). Thrombectomy mRNA showed elevated I‐TAC in RFC (P=0.0007) epidermal growth factor expression in IFC (P=0.0264) but no differences in expression of thrombospondin 1. Conclusions These results demonstrate differential intracoronary cytokine expression in RFC and IFC. Elevated thrombospondin 1 and epidermal growth factor may play an etiological role in erosion.
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Affiliation(s)
- Sujay Chandran
- Norfolk and Norwich University Hospital, Norwich, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | | | - Amina Abdul-Aziz
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Manar Shafat
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Patrick A Calvert
- Papworth Hospital NHS Foundation Trust, Papworth Everard Cambridge, United Kingdom
| | - Kristian M Bowles
- Norfolk and Norwich University Hospital, Norwich, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Marcus D Flather
- Norfolk and Norwich University Hospital, Norwich, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Stuart A Rushworth
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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Lin X, Hu D, Chen G, Shi Y, Zhang H, Wang X, Guo X, Lu L, Black D, Zheng XW, Luo X. Associations of THBS2 and THBS4 polymorphisms to gastric cancer in a Southeast Chinese population. Cancer Genet 2016; 209:215-22. [PMID: 27160021 DOI: 10.1016/j.cancergen.2016.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 04/11/2016] [Accepted: 04/12/2016] [Indexed: 12/28/2022]
Abstract
Thrombospondin-2 (THBS2) and Thrombospondin-4 (THBS4) play an important role in cancer development and progression. However, genetic evidence for their roles in gastric cancer (GC) is lacking. The aim of this study was to explore the association of THBS2/THBS4 polymorphisms with risk and clinicopathological features of GC in a Southeast Chinese population. Eight tagging SNPs in THBS2 and THBS4 were genotyped in 761 GC cases and 739 controls from Chinese case-control sets using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. THBS2/THBS4 mRNA expression was studied in 82 human GC tumors and in mouse stomach tissues by real-time PCR. We found that both THBS2 and THBS4 were abundantly expressed in mouse stomach. THBS4 mRNA expression in human stomach was associated with tumor size (P = 0.002) and tumor-node-metastasis (TNM) (P = 0.010), and THBS2 mRNA expression was associated with the TNM (P = 0.010). Patients with the rs77878919^AG genotype were more prone to developing diffuse-type GC. THBS4 SNPs (rs77878919 and rs7736549) had a modest cumulative effect on the risk of poor prognosis (TNM), with that risk in the highest trend for patients carrying both these unfavorable genotypes. In addition, individuals carrying the THBS4 rs10474606 variant homozygous AA had a modest reduced GC risk. We conclude that THBS2/THBS4 may be functional in playing important role in GC, which was supported by the evidence of the mRNA overexpression in GC and the modest associations of THBS2/THBS4 polymorphisms to GC. These findings might be useful for risk assessment and prognosis prediction of GC.
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Affiliation(s)
- Xiandong Lin
- Department of Pathology, Fujian Provincial Cancer Hospital, the Teaching Hospital of Fujian Medical University, Fuzhou, Fujian 350014, China; Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, Fujian 350014, China
| | - Don Hu
- Department of Pathology, Fujian Provincial Cancer Hospital, the Teaching Hospital of Fujian Medical University, Fuzhou, Fujian 350014, China
| | - Gang Chen
- Department of Pathology, Fujian Provincial Cancer Hospital, the Teaching Hospital of Fujian Medical University, Fuzhou, Fujian 350014, China
| | - Yi Shi
- Department of Pathology, Fujian Provincial Cancer Hospital, the Teaching Hospital of Fujian Medical University, Fuzhou, Fujian 350014, China
| | - Hejun Zhang
- Department of Pathology, Fujian Provincial Cancer Hospital, the Teaching Hospital of Fujian Medical University, Fuzhou, Fujian 350014, China
| | - Xiaojiang Wang
- Department of Pathology, Fujian Provincial Cancer Hospital, the Teaching Hospital of Fujian Medical University, Fuzhou, Fujian 350014, China
| | - Xiaoyun Guo
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Lu Lu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China; Department of Genetics, Genomics, Informatics, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Dennis Black
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Xiong-Wei Zheng
- Department of Pathology, Fujian Provincial Cancer Hospital, the Teaching Hospital of Fujian Medical University, Fuzhou, Fujian 350014, China; Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, Fujian 350014, China.
| | - Xingguang Luo
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
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Kim DJ, Christofidou ED, Keene DR, Hassan Milde M, Adams JC. Intermolecular interactions of thrombospondins drive their accumulation in extracellular matrix. Mol Biol Cell 2015; 26:2640-54. [PMID: 25995382 PMCID: PMC4501361 DOI: 10.1091/mbc.e14-05-0996] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 05/12/2015] [Indexed: 02/01/2023] Open
Abstract
A novel mechanism of intermolecular interactions in trans is identified by which thrombospondin molecules accumulate as puncta within the extracellular matrix. This process depends on a novel, conserved, surface-exposed site on the thrombospondin L-type lectin domain. Thrombospondins participate in many aspects of tissue organization in adult tissue homeostasis, and their dysregulation contributes to pathological processes such as fibrosis and tumor progression. The incorporation of thrombospondins into extracellular matrix (ECM) as discrete puncta has been documented in various tissue and cell biological contexts, yet the underlying mechanisms remain poorly understood. We find that collagen fibrils are disorganized in multiple tissues of Thbs1−/− mice. In investigating how thrombospondins become retained within ECM and thereby affect ECM organization, we find that accumulation of thrombospondin-1 or thrombospondin-5 puncta within cell-derived ECM is controlled by a novel, conserved, surface-exposed site on the thrombospondin L-type lectin domain. This site acts to recruit thrombospondin molecules into ECM by intermolecular interactions in trans. This mechanism is fibronectin independent, can take place extracellularly, and is demonstrated to be direct in vitro. The trans intermolecular interactions can also be heterotypic—for example, between thrombospondin-1 and thrombospondin-5. These data identify a novel concept of concentration-dependent, intermolecular “matrix trapping” as a conserved mechanism that controls the accumulation and thereby the functionality of thrombospondins in ECM.
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Affiliation(s)
- Dae Joong Kim
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, OH 44195
| | | | - Douglas R Keene
- Micro-Imaging Center, Shriners Hospital for Children, Portland, OR 97239
| | - Marwah Hassan Milde
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, OH 44195
| | - Josephine C Adams
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, OH 44195 School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, OH 44195
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8
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Murphy-Ullrich JE, Sage EH. Revisiting the matricellular concept. Matrix Biol 2014; 37:1-14. [PMID: 25064829 PMCID: PMC4379989 DOI: 10.1016/j.matbio.2014.07.005] [Citation(s) in RCA: 286] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/07/2014] [Accepted: 07/08/2014] [Indexed: 12/16/2022]
Abstract
The concept of a matricellular protein was first proposed by Paul Bornstein in the mid-1990s to account for the non-lethal phenotypes of mice with inactivated genes encoding thrombospondin-1, tenascin-C, or SPARC. It was also recognized that these extracellular matrix proteins were primarily counter or de-adhesive. This review reappraises the matricellular concept after nearly two decades of continuous investigation. The expanded matricellular family as well as the diverse and often unexpected functions, cellular location, and interacting partners/receptors of matricellular proteins are considered. Development of therapeutic strategies that target matricellular proteins are discussed in the context of pathology and regenerative medicine.
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Affiliation(s)
- Joanne E Murphy-Ullrich
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294-0019, United States.
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Mustonen E, Ruskoaho H, Rysä J. Thrombospondins, potential drug targets for cardiovascular diseases. Basic Clin Pharmacol Toxicol 2013; 112:4-12. [PMID: 23074998 DOI: 10.1111/bcpt.12026] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 10/07/2012] [Indexed: 01/16/2023]
Abstract
The thrombospondin (TSP) family consists of five multimeric, multidomain calcium-binding glycoproteins that act as regulators of cell-cell and cell-matrix associations as well as interact with other extracellular matrix molecules affecting their function. Increasing interest on cardiac TSP-1, TSP-2 and TSP-4 has emerged, and they have been studied in cardiac hypertrophy, myocardial infarction, heart failure, atherosclerosis and aortic valve stenosis. The aim of this MiniReview is to summarize the current knowledge on each TSP in various cardiovascular pathologies. We specifically emphasize the role of TSPs in cardiac remodelling and evaluate TSPs as potential cardiovascular drug targets. Thrombospondin-1 (TSP-1) is the most studied TSP, being antiangiogenic and able to activate transforming growth factor-β. The functions of TSP-2 and TSP-4 are linked in maintaining the composition of the matrix of the hypertrophied heart, whereas there is very little knowledge on cardiac TSP-3 and TSP-5. TSP-1, TSP-2 and TSP-4 have been shown to affect cardiac remodelling in vivo, for example, by modulating matrix metalloproteinase and transforming growth factor-β activity, collagen synthesis, myofibroblast differentiation, cell death and stretch-mediated augmentation of cardiac contractility. The detrimental role for TSPs in cardiovascular pathophysiology has been clearly demonstrated in knockout mouse models, and augmentation of TSP signalling in the heart during stress and haemodynamic overload might be beneficial. In conclusion, the role of TSP-1, TSP-2 and TSP-4 in cardiac hypertrophy, remodelling after myocardial infarction, heart failure, atherosclerosis and aortic valve stenosis encourages further investigation to validate them as potential drug targets.
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Affiliation(s)
- Erja Mustonen
- Department of Pharmacology and Toxicology, Institute of Biomedicine, Biocenter Oulu, University of Oulu, FIN-90014 Oulu, Finland
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Mosher DF, Adams JC. Adhesion-modulating/matricellular ECM protein families: a structural, functional and evolutionary appraisal. Matrix Biol 2012; 31:155-61. [PMID: 22265890 DOI: 10.1016/j.matbio.2012.01.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 12/26/2011] [Accepted: 12/28/2011] [Indexed: 11/15/2022]
Abstract
The thrombospondins are a family of secreted, oligomeric glycoproteins that interact with cell surfaces, multiple components of the extracellular matrix, growth factors and proteases. These interactions underlie complex roles in cell interactions and tissue homeostasis in animals. Thrombospondins have been grouped functionally with SPARCs, tenascins and CCN proteins as adhesion-modulating or matricellular components of the extracellular milieu. Although all these multi-domain proteins share various commonalities of domains, the grouping is not based on structural homologies. Instead, the terms emphasise the general observations that these proteins do not form large-scale ECM structures, yet act at cell surfaces and function in coordination with the structural ECM and associated extracellular proteins. The designation of adhesion-modulation thus depends on observed tissue and cell culture ECM distributions and on experimentally identified functional properties. To date, the evolutionary relationships of these proteins have not been critically compared: yet, knowledge of their evolutionary histories is clearly relevant to any consideration of functional similarities. In this article, we survey briefly the structural and functional knowledge of these protein families, consider the evolution of each family, and outline a perspective on their functional roles.
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Affiliation(s)
- Deane F Mosher
- Department of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, WI 57706, USA
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Abstract
Thrombospondins are evolutionarily conserved, calcium-binding glycoproteins that undergo transient or longer-term interactions with other extracellular matrix components. They share properties with other matrix molecules, cytokines, adaptor proteins, and chaperones, modulate the organization of collagen fibrils, and bind and localize an array of growth factors or proteases. At cell surfaces, interactions with an array of receptors activate cell-dependent signaling and phenotypic outcomes. Through these dynamic, pleiotropic, and context-dependent pathways, mammalian thrombospondins contribute to wound healing and angiogenesis, vessel wall biology, connective tissue organization, and synaptogenesis. We overview the domain organization and structure of thrombospondins, key features of their evolution, and their cell biology. We discuss their roles in vivo, associations with human disease, and ongoing translational applications. In many respects, we are only beginning to appreciate the important roles of these proteins in physiology and pathology.
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Affiliation(s)
- Josephine C Adams
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom.
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