scholarly journals Interactions of thrombospondin with extracellular matrix proteins: selective binding to type V collagen.

1984 ◽  
Vol 98 (2) ◽  
pp. 646-652 ◽  
Author(s):  
S M Mumby ◽  
G J Raugi ◽  
P Bornstein

Thrombospondin (TS), a protein first described in platelets, was recently shown to be synthesized and secreted by endothelial cells, fibroblasts, and smooth muscle cells. The presence of TS in the extracellular matrix of cultured cells has prompted us to examine the associations of this protein with matrix macromolecules. Interactions of TS with both matrix and serum proteins were tested using an enzyme-linked immunosorbent assay. With this assay we assessed the binding of TS in solution to proteins adsorbed to polystyrene microtiter plates. Among collagens, platelet TS bound to type V but not to types I, III, or IV. This selective interaction was confirmed in experiments using proteins linked to cyanogen bromide-activated Sepharose. TS released from platelets in response to thrombin activation, as well as that secreted by endothelial cells in culture, bound to type V but not to type I collagen-Sepharose. No binding was observed to denatured type V collagen-Sepharose. The binding region for type V collagen was located in a chymotrypsin-produced fragment of TS with chains of Mr = 70,000, after reduction. Interactions of TS with a number of other proteins, including fibronectin, fibrinogen, and laminin, could be demonstrated using the enzyme-linked immunosorbent assay technique but the interpretation of these findings is difficult since comparable binding to protein-Sepharose was not always observed. Our findings suggest that both the extravascular distribution and function of TS in vivo may involve an interaction with type V collagen.

2021 ◽  
Author(s):  
Keren Machol ◽  
Urszula Polak ◽  
Monika Weisz-Hubshman ◽  
I-Wen Song ◽  
Shan Chen ◽  
...  

Abstract Type V collagen is a regulatory fibrillar collagen essential for type I collagen fibril nucleation and organization and its deficiency leads to structurally abnormal extracellular matrix. Haploinsufficiency of the Col5a1 gene encoding α(1) chain of type V collagen is the primary cause of classic Ehlers Danlos Syndrome (EDS). The mechanisms by which this initial insult leads to the spectrum of clinical presentation is not fully understood. Using transcriptome analysis of skin and Achilles tendons from Col5a1 haploinsufficient (Col5a1+/−) mice, we recognized molecular alterations associated with the tissue phenotypes. We identified dysregulation of extracellular matrix components including thrombospondin-1, lysyl oxidase, and lumican in the skin of Col5a1+/− mice when compared to control. We also identified upregulation of Tgf-β in serum and increased expression of pSmad2 in skin from Col5a1+/− mice suggesting Tgf-β dysregulation as a contributor for abnormal wound healing and atrophic scaring seen in classic EDS. Together, these findings support altered matrix to cell signaling as a component of the pathogenesis of the tissue phenotype in classic EDS and point out potential downstream signaling pathways that may be targeted for treatment of the disease.


Author(s):  
Arthur J. Wasserman ◽  
Kathy C. Kloos ◽  
David E. Birk

Type I collagen is the predominant collagen in the cornea with type V collagen being a quantitatively minor component. However, the content of type V collagen (10-20%) in the cornea is high when compared to other tissues containing predominantly type I collagen. The corneal stroma has a homogeneous distribution of these two collagens, however, immunochemical localization of type V collagen requires the disruption of type I collagen structure. This indicates that these collagens may be arranged as heterpolymeric fibrils. This arrangement may be responsible for the control of fibril diameter necessary for corneal transparency. The purpose of this work is to study the in vitro assembly of collagen type V and to determine whether the interactions of these collagens influence fibril morphology.


1982 ◽  
Vol 92 (2) ◽  
pp. 343-349 ◽  
Author(s):  
A Martinez-Hernandez ◽  
S Gay ◽  
E J Miller

Antibodies specific for the alpha 1 (V) chain and native collagen molecules containing the alpha 1 (V) chain have been used in electron immunohistochemical studies of rat kidney to determine the ultrastructural distribution of this class of collagen molecules. In addition, antibodies against type I collagen and whole basement membrane were used as markers for interstitial collagen and authentic basement membranes. Our results indicate that type V collagen is present in the renal interstitium in different forms: in close apposition to interstitial collagen fibers; in the stromal aspect of vascular basement membranes; and as particulate material not bound to other structures. On the basis of these findings, we postulate a binding or connecting function for this collagen type.


1990 ◽  
Vol 95 (4) ◽  
pp. 649-657 ◽  
Author(s):  
D.E. Birk ◽  
J.M. Fitch ◽  
J.P. Babiarz ◽  
K.J. Doane ◽  
T.F. Linsenmayer

The small-diameter fibrils of the chick corneal stroma are heterotypic, composed of both collagen types I and V. This tissue has a high concentration of type V collagen relative to other type I-containing tissues with larger-diameter fibrils, suggesting that heterotypic interactions may have a regulatory role in the control of fibril diameter. The interactions of collagen types I and V were studied using an in vitro self-assembly system. Collagens were purified from lathyritic chick embryos in the presence of protease inhibitors. The type V collagen preparations contained higher molecular weight forms of the alpha 1(V) and alpha 2(V) chains constituting 60–70% of the total. Rotary-shadow electron micrographs showed a persistence of a small, pepsin-sensitive terminal region in an amount consistent with that seen by electrophoresis. In vitro, this purified type V collagen formed thin fibrils with no apparent periodicity, while type I collagen fibrils had a broad distribution of large diameters. However, when type I collagen was mixed with increasing amounts of type V collagen a progressive and significant decrease in both the mean fibril diameter and the variance was observed for D periodic fibrils. The amino-terminal domain of the type V collagen molecule was required for this regulatory effect and in its absence little diameter reducing activity was observed. Electron microscopy using collagen type-specific monoclonal antibodies demonstrated that the fibrils formed were heterotypic, containing both collagen types I and V. These data indicate that the interaction of type V with type I collagen is one mechanism modulating fibril diameter and is at least partially responsible for the regulation of collagen fibril formation.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Yasmin ElTahir ◽  
Amna Al-Araimi ◽  
Remya R. Nair ◽  
Kaija J. Autio ◽  
Hongmin Tu ◽  
...  

Abstract Background Brucella is a facultative intracellular pathogen responsible for zoonotic disease brucellosis. Little is known about the molecular basis of Brucella adherence to host cells. In the present study, the possible role of Bp26 protein as an adhesin was explored. The ability of Brucella protein Bp26 to bind to extracellular matrix (ECM) proteins was determined by enzyme-linked immunosorbent assay (ELISA) and biolayer interferometry (BLI). Results ELISA experiments showed that Bp26 bound in a dose-dependent manner to both immobilized type I collagen and vitronectin. Bp26 bound weakly to soluble fibronectin but did not bind to immobilized fibronectin. No binding to laminin was detected. Biolayer interferometry showed high binding affinity of Bp26 to immobilized type I collagen and no binding to fibronectin or laminin. Mapping of Bp26 antigenic epitopes by biotinylated overlapping peptides spanning the entire sequence of Bp26 using anti Bp26 mouse serum led to the identification of five linear epitopes. Collagen and vitronectin bound to peptides from several regions of Bp26, with many of the binding sites for the ligands overlapping. The strongest binding for anti-Bp26 mouse serum, collagen and vitronectin was to the peptides at the C-terminus of Bp26. Fibronectin did not bind to any of the peptides, although it bound to the whole Bp26 protein. Conclusions Our results highlight the possible role of Bp26 protein in the adhesion process of Brucella to host cells through ECM components. This study revealed that Bp26 binds to both immobilized and soluble type I collagen and vitronectin. It also binds to soluble but not immobilized fibronectin. However, Bp26 does not bind to laminin. These are novel findings that offer insight into understanding the interplay between Brucella and host target cells, which may aid in future identification of a new target for diagnosis and/or vaccine development and prevention of brucellosis.


2004 ◽  
Vol 167 (4) ◽  
pp. 757-767 ◽  
Author(s):  
Tae-Hwa Chun ◽  
Farideh Sabeh ◽  
Ichiro Ota ◽  
Hedwig Murphy ◽  
Kevin T. McDonagh ◽  
...  

During angiogenesis, endothelial cells initiate a tissue-invasive program within an interstitial matrix comprised largely of type I collagen. Extracellular matrix–degradative enzymes, including the matrix metalloproteinases (MMPs) MMP-2 and MMP-9, are thought to play key roles in angiogenesis by binding to docking sites on the cell surface after activation by plasmin- and/or membrane-type (MT) 1-MMP–dependent processes. To identify proteinases critical to neovessel formation, an ex vivo model of angiogenesis has been established wherein tissue explants from gene-targeted mice are embedded within a three-dimensional, type I collagen matrix. Unexpectedly, neither MMP-2, MMP-9, their cognate cell-surface receptors (i.e., β3 integrin and CD44), nor plasminogen are essential for collagenolytic activity, endothelial cell invasion, or neovessel formation. Instead, the membrane-anchored MMP, MT1-MMP, confers endothelial cells with the ability to express invasive and tubulogenic activity in a collagen-rich milieu, in vitro or in vivo, where it plays an indispensable role in driving neovessel formation.


1989 ◽  
Vol 94 (2) ◽  
pp. 371-379
Author(s):  
J.S. McLaughlin ◽  
T.F. Linsenmayer ◽  
D.E. Birk

Chick embryo corneal fibroblasts were grown in culture to study the processes whereby fibroblasts regulate the deposition and organization of the collagenous, secondary stroma. The effects of an existing type I collagen substratum, cell density, and serum concentration on type V collagen synthesis were investigated. Type V collagen represented approximately 20% of the total fibrillar collagen synthesized, regardless of whether the cells were subcultured, grown on untreated or collagen-coated plastic, grown under confluent or subconfluent conditions, or grown in the presence of low (0.1%) or high (10.0%) serum concentrations. The synthesis of type V collagen remained constant at 20% of the total collagen when cells were grown in 1.0% serum, even though total collagen synthesis increased nearly twofold when compared to total synthesis in 0.1% or 10.0% serum. Immunocytochemistry with anti-collagen, type-specific monoclonal antibodies revealed a homogeneous population of cells synthesizing types I and V collagen. The fibrils deposited by cells grown in a three-dimensional collagen matrix contained a helical epitope on the type V molecule that was inaccessible unless the fibrillar structure was disrupted, mimicking the situation in situ. The production in vitro of heterotypic fibrils, with a constant I/V ratio and molecular packing mimicking the natural stroma, offers opportunities for studying in more detail this important process, which is essential for optical transparency.


Sign in / Sign up

Export Citation Format

Share Document