Moderate Cyclic Tensile Strain Alters the Assembly of Cartilage Extracellular Matrix Proteins In Vitro

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Judith Bleuel ◽  
Frank Zaucke ◽  
Gert-Peter Brüggemann ◽  
Juliane Heilig ◽  
Marie-Louise Wolter ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Mechanical Loading ◽  
Tensile Strain ◽  
Matrix Protein ◽  
Extracellular Matrix Proteins ◽  
Matrix Proteins ◽  
Collagen Network ◽  
Cyclic Tensile Strain ◽  
Collagen Ii ◽  
Collagen Ix

Mechanical loading influences the structural and mechanical properties of articular cartilage. The cartilage matrix protein collagen II essentially determines the tensile properties of the tissue and is adapted in response to loading. The collagen II network is stabilized by the collagen II-binding cartilage oligomeric matrix protein (COMP), collagen IX, and matrilin-3. However, the effect of mechanical loading on these extracellular matrix proteins is not yet understood. Therefore, the aim of this study was to investigate if and how chondrocytes assemble the extracellular matrix proteins collagen II, COMP, collagen IX, and matrilin-3 in response to mechanical loading. Primary murine chondrocytes were applied to cyclic tensile strain (6%, 0.5 Hz, 30 min per day at three consecutive days). The localization of collagen II, COMP, collagen IX, and matrilin-3 in loaded and unloaded cells was determined by immunofluorescence staining. The messenger ribo nucleic acid (mRNA) expression levels and synthesis of the proteins were analyzed using reverse transcription-polymerase chain reaction (RT-PCR) and western blots. Immunofluorescence staining demonstrated that the pattern of collagen II distribution was altered by loading. In loaded chondrocytes, collagen II containing fibrils appeared thicker and strongly co-stained for COMP and collagen IX, whereas the collagen network from unloaded cells was more diffuse and showed minor costaining. Further, the applied load led to a higher amount of COMP in the matrix, determined by western blot analysis. Our results show that moderate cyclic tensile strain altered the assembly of the extracellular collagen network. However, changes in protein amount were only observed for COMP, but not for collagen II, collagen IX, or matrilin-3. The data suggest that the adaptation to mechanical loading is not always the result of changes in RNA and/or protein expression but might also be the result of changes in matrix assembly and structure.

scholarly journals Altered Integration of Matrilin-3 into Cartilage Extracellular Matrix in the Absence of Collagen IX

2005 ◽  
Vol 25 (23) ◽  
pp. 10465-10478 ◽  
Author(s):  
Bastian Budde ◽  
Katrin Blumbach ◽  
Joni Ylöstalo ◽  
Frank Zaucke ◽  
Harald W. A. Ehlen ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Knockout Mice ◽  
Matrix Protein ◽  
Protein Extraction ◽  
Direct Interaction ◽  
Matrix Proteins ◽  
Functional Protein ◽  
Cartilage Extracellular Matrix ◽  
Vertebral Bodies ◽  
Collagen Ix

ABSTRACT The matrilins are a family of four noncollagenous oligomeric extracellular matrix proteins with a modular structure. Matrilins can act as adapters which bridge different macromolecular networks. We therefore investigated the effect of collagen IX deficiency on matrilin-3 integration into cartilage tissues. Mice harboring a deleted Col9a1 gene lack synthesis of a functional protein and produce cartilage fibrils completely devoid of collagen IX. Newborn collagen IX knockout mice exhibited significantly decreased matrilin-3 and cartilage oligomeric matrix protein (COMP) signals, particularly in the cartilage primordium of vertebral bodies and ribs. In the absence of collagen IX, a substantial amount of matrilin-3 is released into the medium of cultured chondrocytes instead of being integrated into the cell layer as in wild-type and COMP-deficient cells. Gene expression of matrilin-3 is not affected in the absence of collagen IX, but protein extraction from cartilage is greatly facilitated. Matrilin-3 interacts with collagen IX-containing cartilage fibrils, while fibrils from collagen IX knockout mice lack matrilin-3, and COMP-deficient fibrils exhibit an intermediate integration. In summary, the integration of matrilin-3 into cartilage fibrils occurs both by a direct interaction with collagen IX and indirectly with COMP serving as an adapter. Matrilin-3 can be considered as an interface component, capable of interconnecting macromolecular networks and mediating interactions between cartilage fibrils and the extrafibrillar matrix.

Thromboxane stimulates synthesis of extracellular matrix proteins in vitro

1991 ◽  
Vol 261 (3) ◽  
pp. F488-F494 ◽  
Author(s):  
L. A. Bruggeman ◽  
E. A. Horigan ◽  
S. Horikoshi ◽  
P. E. Ray ◽  
P. E. Klotman
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Mesangial Cells ◽  
Extracellular Matrix Proteins ◽  
Cellular Protein ◽  
Matrix Proteins ◽  
Extracellular Matrix Protein ◽  
Renal Diseases ◽  
Glomerular Mesangial Cells

The vasoconstrictor eicosanoid thromboxane plays an important role in the pathogenesis of several renal diseases. As an autacoid, its local release alters blood flow and induces platelet aggregation. We report a direct stimulatory effect of thromboxane on extracellular matrix protein production and gene expression in vitro. Treatment of two cell types, differentiated mouse teratocarcinoma cells (F9+) and human glomerular mesangial cells, with two different thromboxane analogues resulted in increased production of components of the extracellular matrix including fibronectin and the basement membrane proteins laminin and type IV collagen. These responses to thromboxane were not the result of a mitogenic effect of thromboxane nor the result of an increase in total cellular protein. The increased production of extracellular matrix proteins was, at least in part, due to an increase in the steady-state level of mRNA for these genes. Furthermore, the effect of thromboxane was markedly inhibited by cotreatment with a thromboxane-receptor antagonist. These results suggest a new potential role for thromboxane as a mediator of the sclerotic and fibrotic responses to injury.

scholarly journals Localization of the Domains of the Haemophilus ducreyi Trimeric Autotransporter DsrA Involved in Serum Resistance and Binding to the Extracellular Matrix Proteins Fibronectin and Vitronectin

2008 ◽  
Vol 77 (2) ◽  
pp. 657-666 ◽  
Author(s):  
Isabelle Leduc ◽  
Bonnie Olsen ◽  
Christopher Elkins
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Extracellular Matrix Proteins ◽  
Matrix Proteins ◽  
Haemophilus Ducreyi ◽  
Extracellular Matrix Protein ◽  
Serum Resistance ◽  
Passenger Domain ◽  
Normal Human ◽  
High Level

ABSTRACT Resisting the bactericidal activity of naturally occurring antibodies and complement of normal human serum is an important element in the evasion of innate immunity by bacteria. In the gram-negative mucosal pathogen Haemophilus ducreyi, serum resistance is mediated primarily by the trimeric autotransporter DsrA. DsrA also functions as an adhesin for the extracellular matrix proteins fibronectin and vitronectin and mediates attachment of H. ducreyi to keratinocytes. We sought to determine the domain(s) of the 236-residue DsrA protein required for serum resistance and extracellular matrix protein binding. A 140-amino-acid truncated protein containing only the C-terminal portion of the passenger domain and the entire translocator domain of DsrA exhibited binding to fibronectin and vitronectin and conferred serum resistance to an H. ducreyi serum-sensitive strain. A shorter DsrA construct consisting of only 128 amino acids was unable to bind to extracellular matrix proteins but was serum resistant. We concluded that neither fibronectin binding nor vitronectin binding is required for high-level serum resistance in H. ducreyi.

scholarly journals Purification and Partial Characterization of a Paracoccidioides brasiliensis Protein with Capacity To Bind to Extracellular Matrix Proteins

2005 ◽  
Vol 73 (4) ◽  
pp. 2486-2495 ◽  
Author(s):  
Angel González ◽  
Beatriz L. Gómez ◽  
Soraya Diez ◽  
Orville Hernández ◽  
Angela Restrepo ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Paracoccidioides Brasiliensis ◽  
Sodium Dodecyl ◽  
Extracellular Matrix Proteins ◽  
Matrix Proteins ◽  
Yeast Cells ◽  
Extracellular Matrix Protein ◽  
Dependent Manner ◽  
Fungal Propagules

ABSTRACT Microorganisms adhere to extracellular matrix proteins by means of their own surface molecules. Paracoccidioides brasiliensis conidia have been shown to be capable of interacting with extracellular matrix proteins. We aimed at determining the presence of fungal proteins that could interact with extracellular matrix protein and, if found, attempt their purification and characterization. Various extracts were prepared from P. brasiliensis mycelial and yeast cultures (total homogenates, β-mercaptoethanol, and sodium dodecyl sulfate [SDS] extracts) and analyzed by ligand affinity assays with fibronectin, fibrinogen and laminin. Two polypeptides were detected in both fungal forms. SDS extracts that interacted with all the extracellular matrix protein were tested; their molecular masses were 19 and 32 kDa. Analysis of the N-terminal amino acid sequence of the purified 32-kDa mycelial protein showed substantial homology with P. brasiliensis, Histoplasma capsulatum, and Neurospora crassa hypothetical proteins. Additionally, a monoclonal antibody (MAb) produced against this protein recognized the 32-kDa protein in the SDS extracts of both fungal forms for immunoblot. Immunofluorescence analysis revealed that this MAb reacted not only with mycelia and yeast cells, but also with conidia, indicating that this protein was shared by the three fungal propagules. By immunoelectron microscopy, this protein was detected in the cell walls and in the cytoplasm. Both the 32-kDa purified protein and MAb inhibited the adherence of conidia to the three extracellular matrix proteins in a dose-dependent manner. These findings demonstrate the presence of two polypeptides capable of interacting with extracellular matrix proteins on the surface of P. brasiliensis propagules, indicating that there may be common receptors for laminin, fibronectin, and fibrinogen. These proteins would be crucial for initial conidial adherence and perhaps also in dissemination of paracoccidioidomycosis.

scholarly journals Extracellular matrix protein N-glycosylation mediates immune self-tolerance in Drosophila melanogaster

2021 ◽  
Vol 118 (39) ◽  
pp. e2017460118
Author(s):  
Nathan T. Mortimer ◽  
Mary L. Fischer ◽  
Ashley L. Waring ◽  
Pooja KR ◽  
Balint Z. Kacsoh ◽  
...  
Keyword(s):  
Immune Response ◽  
Extracellular Matrix ◽  
Matrix Protein ◽  
Fat Body ◽  
Extracellular Matrix Proteins ◽  
Recognition System ◽  
Janus Kinase ◽  
Matrix Proteins ◽  
Extracellular Matrix Protein ◽  
Self Tolerance

In order to respond to infection, hosts must distinguish pathogens from their own tissues. This allows for the precise targeting of immune responses against pathogens and also ensures self-tolerance, the ability of the host to protect self tissues from immune damage. One way to maintain self-tolerance is to evolve a self signal and suppress any immune response directed at tissues that carry this signal. Here, we characterize the Drosophila tuSz1 mutant strain, which mounts an aberrant immune response against its own fat body. We demonstrate that this autoimmunity is the result of two mutations: 1) a mutation in the GCS1 gene that disrupts N-glycosylation of extracellular matrix proteins covering the fat body, and 2) a mutation in the Drosophila Janus Kinase ortholog that causes precocious activation of hemocytes. Our data indicate that N-glycans attached to extracellular matrix proteins serve as a self signal and that activated hemocytes attack tissues lacking this signal. The simplicity of this invertebrate self-recognition system and the ubiquity of its constituent parts suggests it may have functional homologs across animals.

Extracellular matrix proteins control the growth of cerebellar medulloblastoma cells

2004 ◽  
Vol 216 (03) ◽  
Author(s):  
U Schüller ◽  
W Hartmann ◽  
A Koch ◽  
K Schilling ◽  
OD Wiestler ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Extracellular Matrix Proteins ◽  
Matrix Proteins ◽  
Cerebellar Medulloblastoma
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