Structure of proteoglycans from different layers of human articular cartilage

Bayliss, Michael T.; Venn, Monica; Maroudas, Alice; Ali, S. Y.

doi:10.1042/bj2090387

Cited by 218 publications

(141 citation statements)

References 37 publications

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“…Under the experimental conditions used in our studies, extraction with 4.OM GuHCl was not quantitative, since some 30% of the total PGs in both loaded and unloaded cartilage remained in the tissue after extraction with this solvent. However, Bayliss et a1 (33) have shown that the yield of PGs extracted with 4.OM GuHCl is related to the amount of surface area of cartilage available to the solvent. Thus, in their studies, virtually all the PGs were extracted from articular cartilage when the tissue had been sectioned on a microtome into slices only 20p thick.…”

Section: Discussionmentioning

confidence: 99%

Composition and glycosaminoglycan metabolism of articular cartilage from habitually loaded and habitually unloaded sites

Slowman

Brandt

1986

Arthritis & Rheumatism

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The uronic acid (proteoglycan, PG) content of cartilage from habitually unloaded sites of normal canine femoral condyles has been shown to be lower than that from habitually loaded regions, even though the glycosaminoglycan (GAG) synthesis is similar. We investigated whether the GAG degradation in unloaded cartilage would be greater than that in loaded cartilage, and we obtained comparative biochemical data concerning the PGs and organization of the extracellular matrix of noi-ma1 loaded and unloaded cartilage. PG extractability (qetermined by sequential guanidinium chloride extracts of cartilage), percentage of PGs forming large aggregates, and hydrodynamic size of the PG monomers (determined by Sepharose 2B chromatography) were essentially the same in loaded and unloaded cartilage. As expected, the uronic acid content of unloaded cartilage was 20% lower than that of loaded cartilage (P < 0.02), while the water and DNA contents of the 2 tissues were not statistically different. There was no difference in the rate of net "S04-GAG synthesis in organ cultures of loaded and unloaded cartilage. Moreover, there was no appreciable difference in the rates of "S04-GAG degradation of loaded and unloaded cartilage, ais determined by "SO4 pulse-chase studies. We have previously shown that selective cyclic compressive stresses applied in vitro to cartilage from loaded areas of canine femoral condyles may increase "S04-GAG synthesis. The present results suggest that the rates of GAG metabolism in loaded and unloaded cartilage under atmospheric pressure in vitro may not reflect the rates which exist in articular joints under compressive loads in vivo.A number of reports have suggested that a causal relationship exists between the proteoglycan (PG) content of connective tissue and the mechanical stress to which it is subjected. Thus, the glycosaminoglycan (GAG) content of load-bearing areas of dermis (l), articular cartilage (2-5), and tendon (6,7) is greater than that of habitually unloaded areas of the same tissues. Furthermore, it is clear that such differences can be modulated in vivo (8,9). An increase in compressive loading of the normal canine shoulder has been shown to produce an in vivo increase in the chondroitin sulfate content of the articular cartilage of the humeral head (9). Conversely, when loading of articular cartilage is reduced, e.g., by immobilization of the ipsilateral limb, net PG synthesis (8,lO) is decreased and the glycosaminoglycan content (1 1 GAG IN LOADED AND UNLOADED CARTILAGE 89either increased or decreased net GAG biosynthesis, depending on the duration of loading (18).In preliminary studies, we found that the level of net GAG synthesis in normal canine femoral condylar cartilage from habitually loaded areas was comparable with that in cartilage from habitually unloaded areas of the same joint (4). Since the uronic acid content of cartilage from unloaded sites is lower than that of cartilage from loaded regions, we hypothesized that the rate of GAG degradation in unloaded cartilage would be g...

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Section: Discussionmentioning

confidence: 99%

Composition and glycosaminoglycan metabolism of articular cartilage from habitually loaded and habitually unloaded sites

Slowman

Brandt

1986

Arthritis & Rheumatism

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“…Interestingly, a recent study demonstrated the presence of regional differences in articular chondrocyte responses to mechanical loading, suggesting the possibility that even under uniform loads different cartilage regions may not respond uniformly (Bevill et al, 2009). As chondrocytes are particularly sensitive to the three-dimensional microenvironment and differentiate in response to local signals (Lemare et al, 1998;Goldring, 2004a;Goldring, 2004b), the expression of cartilage ECM elements likely exhibit regional variation due to subtle differences in loading patterns in distinct joint regions (Bayliss et al, 1983;Nakano and Scott, 1989;Mow et al, 1990;Mizoguchi et al, 1996;Tanaka et al, 2000). It is unknown how velocity-related changes in limb posture affect load orientation.…”

Section: P<005 Limb Loading and Joint Plasticitymentioning

confidence: 99%

Differential limb loading in miniature pigs (Sus scrofa domesticus): a test of chondral modeling theory

Congdon

Hammond

Ravosa

2012

Journal of Experimental Biology

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SUMMARYVariation in mechanical loading is known to influence chondrogenesis during joint formation. However, the interaction among chondrocyte behavior and variation in activity patterns is incompletely understood, hindering our knowledge of limb ontogeny and function. Here, the role of endurance exercise in the development of articular and physeal cartilage in the humeral head was examined in 14 miniature swine (Sus scrofa domesticus). One group was subjected to graded treadmill running over a period of 17 weeks. A matched sedentary group was confined to individual pens. Hematoxylin and eosin staining was performed for histomorphometry of cartilage zone thickness, chondrocyte count and cell area, with these parameters compared multivariately between exercised and sedentary groups. Comparisons were also made with femora from the same sample, focusing on humerus-femur differences between exercised and sedentary groups, within-cohort comparisons of humerus-femur responses and correlated changes within and across joints. This study shows conflicting support for the chondral modeling theory. The humeral articular cartilage of exercised pigs was thinner than that of sedentary pigs, but their physeal cartilage was thicker. While articular and physeal cartilage demonstrated between-cohort differences, humeral physeal cartilage exhibited load-induced responses of greater magnitude than humeral articular cartilage. Controlling for cohort, the humerus showed increased chondrocyte mitosis and cell area, presumably due to relatively greater loading than the femur. This represents the first known effort to evaluate chondral modeling across multiple joints from the same individuals. Our findings suggest the chondral response to elevated loading is complex, varying within and among joints. This has important implications for understanding joint biomechanics and development.

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“…More recent work provides considerable support for the hypothesis that cartilage of the mandibular condyle and TMJ articular disc is affected by local biomechanical effects. Indeed, chondrocytes are highly sensitive to 3-D microenvironment and exhibit changes in differentiation status in response to environmental cues (Lemare et al, 1988;Goldring, 2004a;Goldring, 2004b), with expression of cartilage ECM elements likely reflecting regional variation due to differential loading patterns in distinct joint regions (Bayliss et al, 1983;Nakano and Scott, 1989;Mow et al, 1990;Hamrick, 1999;Tanaka et al, 2000). In this regard, it is interesting that collagen-and proteoglycan-degrading proteinases have been reported in TMJ tissues and synovial fluids (Kiyoshima et al, 1993;Kiyoshima et al, 1994;Marchetti et al, 1999;Puzas et al, 2001;Srinivas et al, 2001).…”

Section: Adaptive Plasticity and Degradation In Masticatory Tissuesmentioning

confidence: 99%

Pushing the limit: masticatory stress and adaptive plasticity in mammalian craniomandibular joints

Ravosa

Kunwar

Stock

et al. 2007

Journal of Experimental Biology

151

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SUMMARY Excessive, repetitive and altered loading have been implicated in the initiation of a series of soft- and hard-tissue responses or `functional adaptations' of masticatory and locomotor elements. Such adaptive plasticity in tissue types appears designed to maintain a sufficient safety factor, and thus the integrity of given element or system, for a predominant loading environment(s). Employing a mammalian species for which considerable in vivo data on masticatory behaviors are available, genetically similar domestic white rabbits were raised on diets of different mechanical properties so as to develop an experimental model of joint function in a normal range of physiological loads. These integrative experiments are used to unravel the dynamic inter-relationships among mechanical loading, tissue adaptive plasticity, norms of reaction and performance in two cranial joint systems:the mandibular symphysis and temporomandibular joint (TMJ). Here, we argue that a critical component of current and future research on adaptive plasticity in the skull, and especially cranial joints, should employ a multifaceted characterization of a functional system, one that incorporates data on myriad tissues so as to evaluate the role of altered load versus differential tissue response on the anatomical, cellular and molecular processes that contribute to the strength of such composite structures. Our study also suggests that the short-term duration of earlier analyses of cranial joint tissues may offer a limited notion of the complex process of developmental plasticity, especially as it relates to the effects of long-term variation in mechanical loads, when a joint is increasingly characterized by adaptive and degradative changes in tissue structure and composition. Indeed, it is likely that a component of the adaptive increases in rabbit TMJ and symphyseal proportions and biomineralization represent a compensatory mechanism to cartilage degradation that serves to maintain the overall functional integrity of each joint system. Therefore, while variation in cranial joint anatomy and performance among sister taxa is, in part, an epiphenomenon of interspecific differences in diet-induced masticatory stresses characterizing the individual ontogenies of the members of a species,this behavioral signal may be increasingly mitigated in over-loaded and perhaps older organisms by the interplay between adaptive and degradative tissue responses.

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Structure of proteoglycans from different layers of human articular cartilage

Cited by 218 publications

References 37 publications

Composition and glycosaminoglycan metabolism of articular cartilage from habitually loaded and habitually unloaded sites

Composition and glycosaminoglycan metabolism of articular cartilage from habitually loaded and habitually unloaded sites

Differential limb loading in miniature pigs (Sus scrofa domesticus): a test of chondral modeling theory

Pushing the limit: masticatory stress and adaptive plasticity in mammalian craniomandibular joints

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