Thrombospondin 2 Modulates Collagen Fibrillogenesis and Angiogenesis

Börnstein, Paul; Kyriakides, Themis R.; Yang, Zhilin; Armstrong, Lucas C.; Birk, David E.

doi:10.1046/j.1087-0024.2000.00005.x

Cited by 94 publications

(80 citation statements)

References 26 publications

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“…More recent, albeit circumstantial, evidence for this view comes from electron microscopic examination of 4-and 8-day postnatal mouse hindlimb flexor tendons. It was found that the tendon fibroblast processes that delimit developing collagen fibril bundles in the growing tendon were less regular and not as closely apposed to the collagen fibrils in TSP2-null as compared with normal tissues (31). Although by no means diagnostic, such changes are compatible with alterations in MMP activity.…”

Section: Fig 4 Lrp Expression In Tsp2 Mouse Dermal Fibroblastsmentioning

confidence: 48%

Extracellular Matrix Metalloproteinase 2 Levels Are Regulated by the Low Density Lipoprotein-related Scavenger Receptor and Thrombospondin 2

Yang

Strickland

Börnstein

2001

Journal of Biological Chemistry

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267

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We have recently shown that the adhesive defect observed in dermal fibroblasts derived from thrombospondin 2 (TSP2)-null mice results from an increase in matrix metalloproteinase 2 (MMP2) levels (Yang, Z., Kyriakides, T. R., and Bornstein, P. (2000) Mol. Biol. Cell 11, 3353-3364). Adhesion was restored by replacement of TSP2 and by inhibitors of MMP2 activity. In pursuing the observation that TSP2 and MMP2 interact, we now demonstrate that this interaction is required for optimal clearance of extracellular MMP2 by fibroblasts. Since TSP2 is known to be endocytosed by the scavenger receptor, low density lipoprotein receptor-related protein (LRP), we determined whether interference with LRP function affected fibroblast adhesion and/or extracellular MMP2 levels. Addition of heparin, which competes for the binding of TSP2 to LRP coreceptor proteoglycans, inhibited adhesion of control but not TSP2-null cells, and a blocking antibody to LRP as well as the LRP inhibitor, receptor-associated protein, also inhibited adhesion and increased MMP2 levels only in control fibroblasts. TSP2 did not inhibit active MMP2 directly and did not inhibit the activation of pro-MMP2. Finally, the internalization of 125 I-MMP2 was reduced in TSP2-null compared with control fibroblasts. We propose that clearance of MMP2-TSP2 complexes by LRP is an important mechanism for the regulation of extracellular MMP2 levels in fibroblasts, and perhaps in other cells. Thus, some features of the phenotype of TSP2-null mice, such as abnormal collagen fibrillogenesis, accelerated wound healing, and increased angiogenesis, could result in part from increased MMP2 activity. Thrombospondins (TSP)1 1 and 2 are large extracellular macromolecules whose diverse functions reflect their ability to bind to multiple cell-surface receptors, cytokines, growth factors, and proteases, and to structural components of the matrix (1, 2). TSP2-null mice display a complex phenotype that is characterized by changes in connective tissues, particularly in response to injury, an increase in vascular density and endosteal bone growth, and a bleeding defect (3-5). Dermal fibroblasts, isolated from adult animals, also show an adhesive defect in vitro that is most evident when cells are plated on a variety of pure protein substrates in the absence of serum. Adhesion was restored by prolonged (48 h) incubation of TSP2-null cells with recombinant mouse TSP2 or by transfection with a TSP2 cDNA gene (6). The basis for this adhesive defect was recently investigated and was shown by zymography to result from an increase in matrix metalloproteinase 2 (MMP2) levels in both the conditioned media and cell layers of cultured cells (6). Although virtually all of the enzyme that was analyzed was in the zymogen or pro-MMP2 form, an increase in active MMP2 in TSP2-null cells was inferred from the observation that inhibitors of MMP2, including TIMP2 and a neutralizing anti-MMP2 antibody, corrected the adhesive defect (6).Both TSP2 and its close relative, TSP1, are known to interact with the scave...

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Section: Fig 4 Lrp Expression In Tsp2 Mouse Dermal Fibroblastsmentioning

confidence: 48%

Extracellular Matrix Metalloproteinase 2 Levels Are Regulated by the Low Density Lipoprotein-related Scavenger Receptor and Thrombospondin 2

Yang

Strickland

Börnstein

2001

Journal of Biological Chemistry

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267

202

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“…Finally, regulatory mechanisms control undesired escalation of angiogenesis. Activation of antiangiogenic factors such as thrombospondin-1 (TSP1) and TSP2, or downregulation of proangiogenic factors such as angiotensin-converting enzyme or c-type lectin domain family 14 member A are involved here (51)(52)(53)(54). ECM reorganization is strongly interlinked with angiogenesis and related proteins were found regulated in both cell types as well.…”

Section: Discussionmentioning

confidence: 98%

Contribution of Human Fibroblasts and Endothelial Cells to the Hallmarks of Inflammation as Determined by Proteome Profiling

Slany

Bileck

Kreutz

et al. 2016

Molecular & Cellular Proteomics

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In order to systematically analyze proteins fulfilling effector functionalities during inflammation, here we present a comprehensive proteome study of inflammatory activated primary human endothelial cells and fibroblasts. Cells were stimulated with interleukin 1-␤ and fractionated in order to obtain secreted, cytoplasmic and nuclear protein fractions. Proteins were submitted to a data-dependent bottom up analytical platform using a QExactive orbitrap and the MaxQuant software for protein identification and label-free quantification. Results were further combined with similarly generated data previously obtained from the analysis of inflammatory activated peripheral blood mononuclear cells. Applying a false discovery rate of less than 0.01 at both, peptide and protein level, a total of 8370 protein groups assembled from 117,599 peptides was identified; mass spectrometry data have been made fully accessible via ProteomeXchange with identifier PXD003406 to PXD003417. Comparative proteome analysis allowed us to determine common and cell type-specific inflammation signatures comprising novel candidate marker molecules and related expression patterns of transcription factors. Cardinal features of inflammation such as interleukin 1-␤ processing and the interferon response differed substantially between the investigated cells. Furthermore, cells also exerted similar inflammation-related tasks; however, by making use of different sets of proteins. Hallmarks of inflammation thus emerged, including angiogenesis, extracellular matrix reorganization, adaptive and innate immune responses, oxidative stress response, cell proliferation and differentiation, cell adhesion and migration in addition to monosaccharide metabolic processes, representing both, common and cell type-specific responsibilities of cells during inflammation. Molecular & Cellular

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“…In a number of studies we have reported that TSP2-null mice produce an abnormal matrix associated with defects in collagen fibrillogenesis. 58 Furthermore, we have found that the solubility of dermal collagen in TSP2-null mice is 2-fold greater than in control animals (T.R.K., unpublished observation, May 2001). Thus, it seems possible that subendothelial collagen fibrils, which are altered in structure and in cross-linking, are present in TSP2-null mice and can influence the formation of platelet aggregates.…”

Section: Contribution Of a Matrix Abnormality To The Bleeding Defectmentioning

confidence: 99%

Megakaryocytes require thrombospondin-2 for normal platelet formation and function

Kyriakides

Rojnuckarin

Reidy

et al. 2003

Blood

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Mice that lack the matricellular angiogenesis inhibitor, thrombospondin-2 (TSP2), display a bleeding diathesis, despite normal blood coagulation and the lack of thrombocytopenia. Although platelets do not contain detectable levels of TSP2, TSP2-null platelets are compromised in their ability to aggregate in vivo in response to denudation of the carotid artery endothelium, and in vitro following exposure to adenosine diphosphate (ADP) . IntroductionThrombospondin-2 (TSP2) is a potent inhibitor of angiogenesis that participates in the processes of development and tissue repair. 1 Specifically, TSP2 is expressed during embryonic development, and during healing of dermal wounds and the foreign body response to implanted biomaterials. [2][3][4][5] In addition, TSP2 has been implicated in the process of tumor growth where it has been shown to inhibit blood vessel formation and limit the growth of squamous cell carcinomas. 6 As a matricellular protein, TSP2 can interact with both cell-surface receptors and extracellular matrix (ECM) components and is believed to function as a modulator of cell-matrix interactions. 7 We have previously shown that mice that lack TSP2 develop a pleiotropic phenotype characterized by connective tissue abnormalities that include abnormal collagen fibrillogenesis. 8 In addition, these mice display increased angiogenesis, increased bone formation, reduced fibroblast adhesion, and an unexpected bleeding diathesis. We hypothesized that the latter could result from an intrinsic qualitative platelet defect, from a subendothelial defect, or both. While we have preliminary evidence for the contribution of a connective tissue abnormality to the bleeding diathesis ("Discussion"), we were surprised to find a reproducible defect in aggregation in the response of TSP2-null platelets to a mild agonist. Since TSP2, unlike TSP1, is not present in platelets we hypothesized that the abnormality might arise earlier, during megakaryocyte (MK) development.Proplatelets are long processes that issue from the surface of fully mature MKs, migrate through the endothelial barrier of marrow sinusoids, and fragment into platelets. At the molecular level, little is understood regarding the regulation of these events, except that ␤1 tubulin and protein kinase C␣ (PKC␣) are essential. 9,10 Analysis of platelet function on the other hand, has benefited from the generation of genetic disruptions in mice that lead to the development of platelet abnormalities. Such models have provided new insights into the functional significance of several platelet proteins. For example, deficiencies in -calpain, 11 ␣ IIb ␤ 3 , 12 platelet endothelial cell adhesion molecule-1 (PECAM-1), 13 and von Willebrand factor (VWF) 14 have led to the development of distinct platelet abnormalities and/or bleeding diatheses. Interestingly, platelet aggregation defects are not always associated with prolonged bleeding times, as was seen in -calpain-null mice. 11 The opposite condition, in which a bleeding diathesis can develop without a platelet defect, ...

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Thrombospondin 2 Modulates Collagen Fibrillogenesis and Angiogenesis

Cited by 94 publications

References 26 publications

Extracellular Matrix Metalloproteinase 2 Levels Are Regulated by the Low Density Lipoprotein-related Scavenger Receptor and Thrombospondin 2

Extracellular Matrix Metalloproteinase 2 Levels Are Regulated by the Low Density Lipoprotein-related Scavenger Receptor and Thrombospondin 2

Contribution of Human Fibroblasts and Endothelial Cells to the Hallmarks of Inflammation as Determined by Proteome Profiling

Megakaryocytes require thrombospondin-2 for normal platelet formation and function

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