scholarly journals Immunohistochemical localization of fibronectin and chondronectin in canine articular cartilage.

1988 ◽  
Vol 36 (6) ◽  
pp. 581-588 ◽  
Author(s):  
N Burton-Wurster ◽  
V J Horn ◽  
G Lust
Keyword(s):  
Articular Cartilage ◽  
External Medium ◽  
Articular Surface ◽  
Immunohistochemical Localization ◽  
Pericellular Matrix ◽  
Osteoarthritic Cartilage ◽  
Matrix Interactions ◽  
The Matrix ◽  
Cut Surface ◽  
Disease Free

We compared the distribution of fibronectin and chondronectin within the matrix of canine articular cartilage. Fibronectin was found throughout the matrix as well as pericellularly. In contrast, chondronectin was observed predominantly associated with the cell or pericellular matrix. Interactions of these molecules with matrix components in the pericellular matrix probably differs, however, since concentrations of hyaluronidase which prevented detection of pericellular fibronectin allowed detection of chondronectin. Chondronectin and fibronectin were detected in osteoarthritic cartilage as well as in disease-free cartilage. Penetration of biotinylated fibronectin into cartilage from the external medium occurred only in osteoarthritic cartilage and proceeded only from the articular surface. Disease-free cartilage appeared to maintain a barrier to fibronectin penetration from the articular surface which was sustained even after the proteoglycan content was markedly depleted by incubation of cartilage with catabolin or lipopolysaccharide. In cartilage that was proteoglycan-depleted, the only detectable penetration of external fibronectin was from the cut surface.

scholarly journals INCREASED FIXATION OF SULFUR35 BY CARTILAGE IN VITRO FOLLOWING DEPLETION OF THE MATRIX BY INTRAVENOUS PAPAIN

1960 ◽  
Vol 112 (5) ◽  
pp. 743-750 ◽  
Author(s):  
T. F. McElligott ◽  
J. L. Potter
Keyword(s):  
Articular Cartilage ◽  
Chondroitin Sulfate ◽  
Intravenous Injection ◽  
Experimental Situation ◽  
Costal Cartilage ◽  
Primary Lesion ◽  
Cartilage Matrix ◽  
Osteoarthritic Cartilage ◽  
The Matrix

The uptake in vitro of sulfur-35 by costal cartilage obtained from nine rabbits 11 days after an intravenous injection of crude papain solution was compared with that in costal cartilage from eight normal untreated rabbits. An increased fixation of the isotope was found in treated animals compared with controls. The depletion of cartilage matrix by papain provided an experimental situation to test the hypothesis that the depletion of matrix which occurs in osteoarthritic cartilage can stimulate increased synthesis of chondroitin sulfate. The results give further support to the view that the primary lesion in osteoarthritis occurs in the matrix rather than in the chondrocyte of articular cartilage.

scholarly journals Localization of proteoglycan monomer and link protein in the matrix of bovine articular cartilage: An immunohistochemical study.

1980 ◽  
Vol 28 (7) ◽  
pp. 621-635 ◽  
Author(s):  
A R Poole ◽  
I Pidoux ◽  
A Reiner ◽  
L H Tang ◽  
H Choi ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Articular Surface ◽  
Guanidine Hydrochloride ◽  
Cartilage Matrix ◽  
Binding Studies ◽  
Superficial Zone ◽  
Surface Culture ◽  
Bovine Articular Cartilage ◽  
Link Protein ◽  
The Matrix

Using monospecific antisera and immunofluorescence microscopy, proteoglycan monomer (PG), and link proteins were demonstrated throughout the extracellular matrix of bovine articular cartilage. A narrow band of strong pericellular staining was usually observed for both molecules, indicating a pericellular concentration of proteoglycan monomer: this conclusion was supported by dye-binding studies. Whereas PG was evenly distributed throughout the remaining matrix, more link protein was detectable in interterritorial sites in middle and deep zones. Well-defined zones of weaker territorial staining for link protein stained strongest for chondroitin sulfate. Trypsin treatment of cartilage resulted in a loss of most of the PG staining, but some selective retention of link protein, particularly around chondrocytes in the superficial zone at and near the articular surface. This residual staining was largely removed if sections were fixed after chondroitinase treatment. After extraction of cartilage with 4M guanidine hydrochloride, only PG remained and this was concentrated in the superficial zone. These observations are shown to support the concept of aggregation of PG and link protein with hyaluronic acid (HA) in cartilage matrix, and the binding of PG and link protein to HA, which is attached to the chondrocyte surface. Culture of cartilage depleted of PG and link protein by trypsin demonstrated that individual chondrocytes can secrete both PG and link proteins and that the organization of cartilage matrix can be regenerated in part over a period of 4 days.

scholarly journals Comparison of Compressive Stress-Relaxation Behavior in Osteoarthritic (ICRS Graded) Human Articular Cartilage

2017 ◽  
Author(s):  
Rajesh Kumar ◽  
David M. Pierce ◽  
Vidar Isaksen ◽  
Catharina de Lange Davies ◽  
Jon O. Drogset ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Stress Relaxation ◽  
Computational Models ◽  
Articular Surface ◽  
Significant Loss ◽  
Relaxation Behavior ◽  
Human Articular Cartilage ◽  
Osteoarthritic Cartilage ◽  
Human Cartilage ◽  
Stress Relaxation Behavior

Osteoarthritis (OA) is a common joint disorder found mostly in elderly people. The role of mechanical behavior in the progression of OA is complex and remains unclear. The stress-relaxation behavior of human articular cartilage in clinically defined osteoarthritic stages may have importance in diagnosis and prognosis of OA. In this study we investigated differences in the biomechanical responses among human cartilage of ICRS grades I, II and III using polymer dynamics theory. We collected 24 explants of human articular cartilage (eight each of ICRS grade I, II and III) and acquired stress-relaxation data applying a continuous load on the articular surface of each cartilage explant for 1180 s. We observed a significant decrease in Young’s modulus, stress-relaxation time, and stretching exponent in advanced stages of OA (ICRS grade III). The stretch exponential model indicated that significant loss in hyaluronic acid polymer might be the reason for the loss of proteoglycan in advanced OA. This work encourages further biomechanical modelling of osteoarthritic cartilage utilizing these data as input parameters to enhance the fidelity of computational models aimed at revealing how mechanical behaviors play a role in pathogenesis of OA.

Alterations in the Mechanical Properties of the Human Chondrocyte Pericellular Matrix With Osteoarthritis

2003 ◽  
Vol 125 (3) ◽  
pp. 323-333 ◽  
Author(s):  
Leonidas G. Alexopoulos ◽  
Mansoor A. Haider ◽  
Thomas P. Vail ◽  
Farshid Guilak
Keyword(s):  
Articular Cartilage ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Theoretical Models ◽  
Significant Loss ◽  
Surface Zone ◽  
Human Articular Cartilage ◽  
Pericellular Matrix ◽  
Osteoarthritic Cartilage ◽  
Isolation Technique

In articular cartilage, chondrocytes are surrounded by a pericellular matrix (PCM), which together with the chondrocyte have been termed the “chondron.” While the precise function of the PCM is not known there has been considerable speculation that it plays a role in regulating the biomechanical environment of the chondrocyte. In this study, we measured the Young’s modulus of the PCM from normal and osteoarthritic cartilage using the micropipette aspiration technique, coupled with a newly developed axisymmetric elastic layered half-space model of the experimental configuration. Viable, intact chondrons were extracted from human articular cartilage using a new microaspiration-based isolation technique. In normal cartilage, the Young’s modulus of the PCM was similar in chondrons isolated from the surface zone (68.9±18.9 kPa) as compared to the middle and deep layers (62.0±30.5 kPa). However, the mean Young’s modulus of the PCM (pooled for the two zones) was significantly decreased in osteoarthritic cartilage (66.5±23.3 kPa versus 41.3±21.1 kPa, p<0.001). In combination with previous theoretical models of cell-matrix interactions in cartilage, these findings suggest that the PCM has an important influence on the stress-strain environment of the chondrocyte that potentially varies with depth from the cartilage surface. Furthermore, the significant loss of PCM stiffness that was observed in osteoarthritic cartilage may affect the magnitude and distribution of biomechanical signals perceived by the chondrocytes.

scholarly journals Topographic localization of a 116,000-dalton protein in cartilage.

1985 ◽  
Vol 33 (2) ◽  
pp. 127-133 ◽  
Author(s):  
R S Fife ◽  
G L Hook ◽  
K D Brandt
Keyword(s):  
Articular Cartilage ◽  
Matrix Protein ◽  
Articular Surface ◽  
Intense Staining ◽  
Normal Cartilage ◽  
Subunit Protein ◽  
Monolayer Cultures ◽  
Noncollagenous Protein ◽  
The Matrix ◽  
Surface Staining

A disulfide-bonded greater than 400,000-dalton (greater than 400-kD) protein with 116-kD subunits in hyaline cartilage from several species has recently been described. It constitutes 2-4% of the total noncollagenous protein in 4 M guanidinium chloride extracts of normal articular cartilage and accounts for most of the total noncollagen, nonproteoglycan protein synthesized in short-term organ cultures of canine articular cartilage. In the present study, immunofluorescence techniques were used to examine the topographic distribution of the 116-kD subunit protein in normal cartilage. In specimens of normal adult articular cartilage from several species, the protein was located throughout the matrix. More intense staining was observed at the articular surface than in the remainder of the uncalcified cartilage. In contrast, in fetal cartilage, the protein was uniformly distributed throughout the matrix without a marked increase in surface staining. Normal canine menisci and annulus fibrosus also demonstrated moderate fluorescence after incubation with the antiserum to the 116-kD subunit protein. Normal canine nucleus pulposus, synovium, aorta, and monolayer cultures of canine synovial cells exhibited only weak immunofluorescence after incubation with the antiserum. Therefore, the 116-kD subunit protein appears to be a ubiquitous matrix protein in cartilage.

scholarly journals Immunofluorescence-guided atomic force microscopy to measure the micromechanical properties of the pericellular matrix of porcine articular cartilage

2012 ◽  
Vol 9 (76) ◽  
pp. 2997-3007 ◽  
Author(s):  
Rebecca E. Wilusz ◽  
Louis E. DeFrate ◽  
Farshid Guilak
Keyword(s):  
Atomic Force Microscopy ◽  
Articular Cartilage ◽  
Elastic Moduli ◽  
Articular Surface ◽  
Biomechanical Properties ◽  
Pericellular Matrix ◽  
Type Vi Collagen ◽  
Force Microscopy ◽  
Micromechanical Properties ◽  
Atomic Force

The pericellular matrix (PCM) is a narrow region that is rich in type VI collagen that surrounds each chondrocyte within the extracellular matrix (ECM) of articular cartilage. Previous studies have demonstrated that the chondrocyte micromechanical environment depends on the relative properties of the chondrocyte, its PCM and the ECM. The objective of this study was to measure the influence of type VI collagen on site-specific micromechanical properties of cartilage in situ by combining atomic force microscopy stiffness mapping with immunofluorescence imaging of PCM and ECM regions in cryo-sectioned tissue samples. This method was used to test the hypotheses that PCM biomechanical properties correlate with the presence of type VI collagen and are uniform with depth from the articular surface. Control experiments verified that immunolabelling did not affect the properties of the ECM or PCM. PCM biomechanical properties correlated with the presence of type VI collagen, and matrix regions lacking type VI collagen immediately adjacent to the PCM exhibited higher elastic moduli than regions positive for type VI collagen. PCM elastic moduli were similar in all three zones. Our findings provide further support for type VI collagen in defining the chondrocyte PCM and contributing to its biological and biomechanical properties.

scholarly journals Articular-cartilage matrix γ-carboxyglutamic acid-containing protein. Characterization and immunolocalization

1992 ◽  
Vol 282 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R Loeser ◽  
C S Carlson ◽  
H Tulli ◽  
W G Jerome ◽  
L Miller ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Matrix Vesicles ◽  
Protein Characterization ◽  
Pericellular Matrix ◽  
Guanidinium Chloride ◽  
Carboxyglutamic Acid ◽  
The Matrix ◽  
Important Regulator ◽  
Immunohistochemical Studies ◽  
Bovine Cartilage

Matrix gamma-carboxyglutamic acid (Gla)-containing protein (MGP) was found to be present in articular cartilage by Western-blot analysis of guanidinium chloride extracts of human and bovine cartilage and was further localized by immunohistochemical studies on human and monkey specimens. In newborn articular cartilage MGP was present diffusely throughout the matrix, whereas in growth-plate cartilage it was seen mainly in late hypertrophic and calcifying-zone chondrocytes. In adult articular cartilage MGP was present primarily in chondrocytes and the pericellular matrix. Immunoelectron microscopy studies revealed an association between MGP and vesicular structures with an appearance consistent with matrix vesicles. MGP may be an important regulator of cartilage calcification because of its localization in cartilage and the known affinity of Gla-containing proteins for Ca2+ and hydroxyapatite.

Quantification and immunolocalisation of porcine articular and growth plate cartilage collagens

1993 ◽  
Vol 105 (4) ◽  
pp. 975-984 ◽  
Author(s):  
R.J. Wardale ◽  
V.C. Duance
Keyword(s):  
Articular Cartilage ◽  
Growth Plate ◽  
Type I Collagen ◽  
Articular Surface ◽  
Dry Weight ◽  
Type I ◽  
Collagen Types ◽  
Growth Plate Cartilage ◽  
The Matrix ◽  
Cross Links

The collagens of growth plate and articular cartilage from 5–6 month old commercial pigs were characterised. Growth plate cartilage was found to contain less total collagen than articular cartilage as a proportion of the dry weight. Collagen types I, II, VI, IX and XI are present in both growth plate and articular cartilage whereas type X is found exclusively in growth plate cartilage. Types III and V collagen could not be detected in either cartilage. Type I collagen makes up at least 10% of the collagenous component of both cartilages. There are significant differences in the ratios of the quantifiable collagen types between growth plate and articular cartilage. Collagen types I, II, and XI were less readily extracted from growth plate than from articular cartilage following pepsin treatment, although growth plate cartilage contains less of the mature collagen cross-links, hydroxylysyl-pyridinoline and lysyl-pyridinoline. Both cartilages contain significant amounts of the divalent reducible collagen cross-links, hydroxylysyl-ketonorleucine and dehydro-hydroxylysinonorleucine. Immunofluorescent localisation indicated that type I collagen is located predominantly at the surface of articular cartilage but is distributed throughout the matrix in growth plate. Types II and XI are located in the matrix of both cartilages whereas type IX is predominantly pericellular in the calcifying region of articular cartilage and the hypertrophic region of the growth plate. Collagen type VI is located primarily as a diffuse area at the articular surface.

scholarly journals The Dynamic Mechanical Environment of the Chondrocyte: A Biphasic Finite Element Model of Cell-Matrix Interactions Under Cyclic Compressive Loading

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Eunjung Kim ◽  
Farshid Guilak ◽  
Mansoor A. Haider
Keyword(s):  
Articular Cartilage ◽  
Material Properties ◽  
Axial Strain ◽  
Compressive Loading ◽  
Osteoarthritic Cartilage ◽  
Cell Matrix ◽  
Cellular Environment ◽  
Matrix Interactions ◽  
Biphasic Finite Element ◽  
Cell Matrix Interactions

Cyclic mechanical loading of articular cartilage results in a complex biomechanical environment at the scale of the chondrocytes that strongly affects cellular metabolic activity. Under dynamic loading conditions, the quantitative relationships between macroscopic loading characteristics and solid and fluid mechanical variables in the local cellular environment are not well understood. In this study, an axisymmetric multiscale model of linear biphasic cell-matrix interactions in articular cartilage was developed to investigate the cellular microenvironment in an explant subjected to cyclic confined compressive loading. The model was based on the displacement-velocity-pressure (u-v-p) mixed-penalty weighted residual formulation of linear biphasic theory that was implemented in the COMSOL MULTIPHYSICS software package. The microscale cartilage environment was represented as a three-zone biphasic region consisting of a spherical chondrocyte with encapsulating pericellular matrix (PCM) that was embedded in a cylindrical extracellular matrix (ECM) subjected to cyclic confined compressive loading boundary conditions. Biphasic material properties for the chondrocyte and the PCM were chosen based on previous in vitro micropipette aspiration studies of cells or chondrons isolated from normal or osteoarthritic cartilage. Simulations performed at four loading frequencies in the range 0.01–1.0 Hz supported the hypothesized dual role of the PCM as both a protective layer for the cell and a mechanical transducer of strain. Time varying biphasic variables at the cellular scale were strongly dependent on relative magnitudes of the loading period, and the characteristic gel diffusion times for the ECM, the PCM, and the chondrocyte. The multiscale simulations also indicated that axial strain was significantly amplified in the range 0.01–1.0 Hz, with a decrease in amplification factor and frequency insensitivity at the higher frequencies. Simulations of matrix degradation due to osteoarthritis indicated that strain amplification factors were more significantly altered when loss of matrix stiffness was exclusive to the PCM. The findings of this study demonstrate the complex dependence of dynamic mechanics in the local cellular environment of cartilage on macroscopic loading features and material properties of the ECM and the chondron.

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