Age-related changes in the composition and structure of human articular-cartilage proteoglycans.
Ontology highlight
ABSTRACT:
SUBMITTER: Bayliss MT
PROVIDER: S-EPMC1186290 | biostudies-other | 1978 Dec
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Monoclonal antibodies were prepared that recognize different age-related epitopes on proteoglycan subunits of high buoyant density isolated from human epiphysial and articular cartilages. Antibody EFG-4 (IgG1) recognizes a proteinase-sensitive segment associated with the core protein. Antibody BCD-4 (IgG1) reacts with keratan sulphate bound to core protein. Both epitopes are minimally expressed in foetal cartilage and increase with age after birth to become maximally expressed in adult cartilage by about 30 years of age. In contrast, monoclonal antibody alpha HFPG-846 (IgM) recognizes a core-protein-related epitope that is maximally expressed in young foetal cartilage, declines up to birth and thereafter and is almost absent after about 30 years of age. Antibody alpha HFPG-846 was used to isolate by immuno-affinity chromatography two subpopulations of proteoglycan subunits from a 16-year-old-human cartilage proteoglycan subunit preparation. Only the antibody-unbound population showed a significant reaction with antibodies EGF-4 and BCD-4. The amino acid and carbohydrate compositions of these proteoglycan fractions were different, and one (antibody-bound) resembled those of foetal and the other (antibody-unbound) resembled those of adult proteoglycans isolated from 24-27-week-old-foetal and 52-56-year-old-adult cartilage respectively. These observations demonstrate that human cartilages contain at least two chemically and immunochemically distinct populations of proteoglycans, the proportions and content of which are age-dependent. It is likely that these populations represent the products of different genes, though their heterogeneity may be compounded by the result of different post-translation modifications.
| S-EPMC1146787 | biostudies-other
Project description:Proteoglycans were extracted from the articular cartilage of foetal, calf and adult bovine metacarpal-phalangeal joints with 4m-guanidinium chloride. After extraction, the high-density proteoglycans (PG-I fractions) were prepared by sedimentation in two sequential CsCl-density-gradient procedures [Swann, Powell & Sotman (1979) J. Biol. Chem.254, 945-954]. The PG-I fractions from foetal, calf and adult tissues accounted for 75%, 52% and 46% respectively of the extracted components. The glucosamine, galactose, N-acetylneuraminic acid and protein contents increased with age. The overall amino acid compositions of PG-I fractions were similar. Fractionation of PG-I-fraction samples on a Bio-Gel A-50m column indicated that the molecular weight decreased with age. The PG-I fractions were specifically (3)H-labelled by treatment with galactose oxidase followed by reduction with NaB(3)H(4). The (3)H radioactivity was incorporated into both galactose and galactosamine residues of different carbohydrate side chains. The elution profiles of alkaline borohydride-treated foetal, calf and adult PG-I-fraction samples on a Sepharose 6B column showed that the molecular weights of chondroitin sulphate chains were 13500, 12000 and 10500 in foetal, calf and adult tissues respectively. Fractionation of the alkaline borohydride-treated foetal, calf and adult PG-I-fraction samples and (3)H-labelled calf and adult PG-I-fraction samples on a Bio-Gel P-10 column showed that there was an inverse relationship between the low-molecular-weight O-linked oligosaccharides and the higher-molecular-weight sialic acid-containing constituents at different ages. The oligosaccharide components of foetal, calf and adult PG-I-fraction samples represented 79%, 69% and 36% respectively of the total sialic acid content of the proteoglycans. Similarly in the (3)H-labelled calf and adult samples 75% and 30% of the total radioactivity were present in the oligosaccharide components respectively. Digestion with chondroitinase AC-II and infrared analyses showed that the PG-I-fraction F and C samples contained primarily chondroitin 4-sulphate chains whereas PG-I-fraction sample A was 6-sulphated. These studies show that the major proteoglycans (PG-I fractions) in the articular cartilage of foetal, calf and adult animals differ in the content, types and structure of the chondroitin sulphate, keratan sulphate and oligosaccharide constituents. These changes in proteoglycan structure reflect the gross age-related changes in the chemical composition of the tissue.
| S-EPMC1162627 | biostudies-other
Project description:Link proteins were identified immunologically in human articular-cartilage protein preparations from various individuals. Irrespective of age, all cartilages contained three link proteins of mol.wts. 48000, 44000 and 41000. However, with increasing age, multiple additional components of mol.wts. 26000-30000 were commonly observed under conditions where disulphide bonds were reduced.
| S-EPMC1152237 | biostudies-other
Project description:Hui2014 - Age-related changes in articular
cartilage
This model is described in the article:
Oxidative changes and
signalling pathways are pivotal in initiating age-related
changes in articular cartilage
Wang Hui1, David A Young1, Andrew D
Rowan1, Xin Xu2, Tim E Cawston1, Carole J Proctor1,3
Annals of the Rheumatic Diseases
Abstract:
Objective: To use a computational approach to investigate
the cellular and extracellular matrix changes that occur with
age in the knee joints of mice. Methods: Knee joints from an
inbred C57/BL1/6 (ICRFa) mouse colony were harvested at
3–30?months of age. Sections were stained with H&E,
Safranin-O, Picro-sirius red and antibodies to matrix
metalloproteinase-13 (MMP-13), nitrotyrosine, LC-3B, Bcl-2, and
cleaved type II collagen used for immunohistochemistry. Based
on this and other data from the literature, a computer
simulation model was built using the Systems Biology Markup
Language using an iterative approach of data analysis and
modelling. Individual parameters were subsequently altered to
assess their effect on the model. Results: A progressive loss
of cartilage matrix occurred with age. Nitrotyrosine, MMP-13
and anaplastic lymphoma kinase (ALK1) staining in cartilage
increased with age with a concomitant decrease in LC-3B and
Bcl-2. Stochastic simulations from the computational model
showed a good agreement with these data, once transforming
growth factor-? signalling via ALK1/ALK5 receptors was
included. Oxidative stress and the interleukin 1 pathway were
identified as key factors in driving the cartilage breakdown
associated with ageing. Conclusions: A progressive loss of
cartilage matrix and cellularity occurs with age. This is
accompanied with increased levels of oxidative stress,
apoptosis and MMP-13 and a decrease in chondrocyte autophagy.
These changes explain the marked predisposition of joints to
develop osteoarthritis with age. Computational modelling
provides useful insights into the underlying mechanisms
involved in age-related changes in musculoskeletal tissues.
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2024-09-02 | BIOMD0000000560 | BioModels
Project description:Total tissue content and molecular mass of hyaluronic acid was determined in papain digests of human articular cartilage using a sensitive radiosorbent assay [Laurent & Tengblad (1980) Anal. Biochem. 109, 386-394]. 1) Hyaluronic acid content increased from 0.5 microgram/mg wet wt. to 2.5 micrograms/mg wet wt. between the ages of 2.5 years and 86 years. 2) Hyaluronic acid chain size decreased from Mr 2.0 x 10(6) to 3.0 x 10(5) over the same age range. 3) There was no age-related change in the size of newly-synthesized hyaluronic acid, which was of very high molecular mass, in both immature and mature cartilage. The results are consistent with an age-related decrease in proteoglycan aggregate size and suggest that modification of the hyaluronic acid chain may take place in the extracellular matrix.
| S-EPMC1148875 | biostudies-other
Project description:The heterogeneity of the components of proteoglycan aggregates, their stoichiometry within the aggregate and the aggregates' stability was investigated in normal human articular cartilage specimens (age-range newborn to 63 years). Proteoglycans were extracted from tissue by sequentially extracting them with PBS alone, PBS containing oligosaccharides of hyaluronan, and PBS containing solutions of increasing guanidinium chloride concentration (1 M, 2 M, 3 M and 4 M). A high proportion of each of the components of the proteoglycan aggregate, i.e. uronic acid, sulphated glycosaminoglycan, hyaluronan binding domain of aggrecan (G1-domain), link protein (LP) and hyaluronan, was extracted from immature cartilage by PBS alone and PBS containing oligosaccharides of hyaluronan. This was in marked contrast to adult cartilage, which required high concentrations of guanidinium chloride for the efficient extraction of these components. The molar ratios of total G1-domain:LP and the G1-domain associated with aggrecan:LP also differed markedly between immature and mature cartilage and between each of the sequential extracts. The concentration of LP was less than that of the G1-domain in all extracts of cartilage from individuals over 13 years, but this was particularly noticeable in the 1 M guanidinium chloride extracts, and it was surmised that a deficiency in LP produces unstable aggregates in situ. The fragmentation of LP, which is known to occur with advancing age, did not influence the extractability of LP, and fragments were present in each of the sequential extracts. Therefore the generally accepted model of proteoglycan aggregation presented in the literature, which is mostly derived from analysis of immature animal cartilage, cannot be used to describe the structure and organization of aggregates in adult human articular cartilage, where a heterogeneous population of complexes exist that have varying degrees of stability.
| S-EPMC1223159 | biostudies-other
Project description:Full-depth plugs of adult human articular cartilage were cut into serial slices from the articular surface and analysed for their glycosaminoglycan content. The amount of chondroitin sulphate was highest in the mid-zone, whereas keratan sulphate increased progressively through the depth. Proteoglycans were isolated from each layer by extraction with 4M-guanidinium chloride followed by centrifugation in 0.4M-guanidinium chloride/CsCl at a starting density of 1.5 g/ml. The efficiency with which proteoglycans were extracted depended on slice thickness, and extraction was complete only when cartilage from each zone was sectioned at 20 microns or less. When thick sections (250 microns) were extracted, hyaluronic acid was retained in the tissue. Most of the proteoglycans, extracted from each layer under optimum conditions, could interact with hyaluronic acid to form aggregates, although the extent of aggregation was less in the deeper layers. Two pools of proteoglycan were identified in all layers by gel chromatography (Kav. 0.33 and 0.58). The smaller of these was rich in keratan sulphate and protein, and gradually increased in proportion through the cartilage depth. Chondroitin sulphate chain size was constant in all regions. The changes in composition and structure observed were consistent with the current model for hyaline-cartilage proteoglycans and were similar to those observed with increasing age in human articular cartilage.
| S-EPMC1154105 | biostudies-other
Project description:ObjectiveTo use a computational approach to investigate the cellular and extracellular matrix changes that occur with age in the knee joints of mice.MethodsKnee joints from an inbred C57/BL1/6 (ICRFa) mouse colony were harvested at 3-30 months of age. Sections were stained with H&E, Safranin-O, Picro-sirius red and antibodies to matrix metalloproteinase-13 (MMP-13), nitrotyrosine, LC-3B, Bcl-2, and cleaved type II collagen used for immunohistochemistry. Based on this and other data from the literature, a computer simulation model was built using the Systems Biology Markup Language using an iterative approach of data analysis and modelling. Individual parameters were subsequently altered to assess their effect on the model.ResultsA progressive loss of cartilage matrix occurred with age. Nitrotyrosine, MMP-13 and activin receptor-like kinase-1 (ALK1) staining in cartilage increased with age with a concomitant decrease in LC-3B and Bcl-2. Stochastic simulations from the computational model showed a good agreement with these data, once transforming growth factor-β signalling via ALK1/ALK5 receptors was included. Oxidative stress and the interleukin 1 pathway were identified as key factors in driving the cartilage breakdown associated with ageing.ConclusionsA progressive loss of cartilage matrix and cellularity occurs with age. This is accompanied with increased levels of oxidative stress, apoptosis and MMP-13 and a decrease in chondrocyte autophagy. These changes explain the marked predisposition of joints to develop osteoarthritis with age. Computational modelling provides useful insights into the underlying mechanisms involved in age-related changes in musculoskeletal tissues.
| S-EPMC4752670 | biostudies-literature
Project description:Monoclonal antibodies produced against chondroitinase-treated human adult cartilage proteoglycans were selected for their ability to recognize epitopes on native proteoglycans. Binding analyses revealed that four of these monoclonal antibodies (BCD-4, BCD-7, EFG-4 and KPC-190) each recognized a different epitope on the same proteoglycan molecule which represents a subpopulation of a high buoyant density (D1) fraction of human articular cartilage proteoglycans (10, 30, 50 and 60% in fetal-newborn, 1.5 years old, 15 years old and 52-56 years old cartilages, respectively). Analysis of epitope specificities revealed that BCD-7 and EFG-4 monoclonal antibodies recognized epitopes on proteoglycan monomer which are associated with the protein structure in that they are sensitive to cleavage by Pronase, papain and alkali treatment and do not include keratan sulphate, chondroitin sulphate or oligosaccharides. The BCD-4 and KPC-190 epitopes also proved to be sensitive to Pronase or papain digestion or to alkali treatment, but keratanase or endo-beta-galactosidase also reduced the immunoreactivity of these epitopes. These observations indicate that the BCD-4 and KPC-190 epitopes represent peptides substituted with keratan sulphate or keratan sulphate-like structures. The BCD-4 epitope is, however, absent from a keratan sulphate-rich fragment of human adult proteoglycan, while the other three epitopes were detected in this fragment. None of these four epitopes were detected in the link proteins of human cartilage, in the hyaluronic acid-binding region of human newborn cartilage proteoglycan, in Swarm rat chondrosarcoma proteoglycan, in chicken limb bud proteoglycan monomer and in the small dermatan sulphate-proteoglycan of bovine costal cartilage. EFG-4 and KPC-190 epitopes were not detected in human fetal cartilage proteoglycans, although fetal molecules contained trace amounts of epitopes reactive with BCD-4 and BCD-7 antibodies.
| S-EPMC1146523 | biostudies-other
Project description:Proteoglycans were extracted from normal human articular cartilage of various ages with 4M-guanidinium chloride and were purified and characterized by using preformed linear CsCl density gradients. With advancing age, there was a decrease in high-density proteoglycans of low protein/uronic acid weight ratio and an increase in the proportion of lower-density proteoglycans, richer in keratan sulphate and protein. Proteoglycans of each age were also shown to disaggregate in 4M-guanidinium chloride and at low pH and to reaggregate in the presence of hyaluronic acid and/or low-density fractions. Osteoarthrotic-cartilage extracts had an increased content of higher-density proteoglycans compared with normal cartilage of the same age, and results also suggested that these were not mechanical or enzymic degradation products, but were possibly proteoglycans of an immature nature.
| S-EPMC1184201 | biostudies-other