Age-related changes in the sulphation of the chondroitin sulphate linkage region from human articular cartilage aggrecan

2001 ◽  
Vol 358 (2) ◽  
pp. 523-528 ◽  
Author(s):  
Robert M. LAUDER ◽  
Thomas N. HUCKERBY ◽  
Gavin M. BROWN ◽  
Michael T. BAYLISS ◽  
Ian A. NIEDUSZYNSKI
Keyword(s):  
Articular Cartilage ◽  
Chondroitin Sulphate ◽  
Basic Structure ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Human Articular Cartilage ◽  
Linkage Region ◽  
Age Related ◽  
Age Related Changes

The chondroitin sulphate (CS) linkage regions have been isolated from human articular cartilage aggrecan (from 10- to 72-year-olds) by chondroitin ABC endolyase digestion and size-exclusion chromatography. Linkage region hexasaccharides have been characterized and their abundance estimated by high-pH anion-exchange chromatography. The basic structure for the CS linkage region oligosaccharides identified from human aggrecan is as follows: ΔUA(β1–3)GalNAc[0S/4S/6S](β1–4)GlcA(β1–3)Gal[0S/6S](β1–3)Gal(β1–4)Xyl, where ΔUA represents 4,5-unsaturated hexuronic acid, 4S and 6S represent an O-ester sulphate group on C-4 and C-6 respectively, and 0S represents zero sulphation. There are significant age-related changes in the abundance of the various N-acetylgalactosamine (GalNAc) sulphation forms identified, occurring up to approx. 20 years old. During the period from 10 to 20 years old the level of GalNAc 6-sulphation at the linkage region increases from approx. 43% to approx. 75%, while there is a corresponding reduction in unsulphated (approx. 30% to approx. 20%) and 4-sulphated (approx. 25% to approx. 6%) GalNAc residues. There is also an increase in the incidence of linkage region galactose 6-sulphation (approx. 2% to approx. 10%) which was only observed in linkage regions with GalNAc 6-sulphation. Beyond 20 years old there are few changes in the relative abundance of these GalNAc sulphation variants; however, there is a slight increase in the abundance of 6-sulphation between approx. 20 years old and approx. 40 years old and a slight decrease in its abundance beyond approx. 40 years old. Our data show that in the majority of chains from tissues of all ages the GalNAc residue closest to the linkage region is 6-sulphated, but the level of GalNAc 6-sulphation within the linkage region is lower than the average level observed within the repeat region.

scholarly journals Age-related changes in the sulphation of the chondroitin sulphate linkage region from human articular cartilage aggrecan

2001 ◽  
Vol 358 (2) ◽  
pp. 523 ◽  
Author(s):  
Robert M. LAUDER ◽  
Thomas N. HUCKERBY ◽  
Gavin M. BROWN ◽  
Michael T. BAYLISS ◽  
Ian A. NIEDUSZYNSKI
Keyword(s):  
Articular Cartilage ◽  
Chondroitin Sulphate ◽  
Human Articular Cartilage ◽  
Linkage Region ◽  
Age Related ◽  
Age Related Changes

Increased incidence of unsulphated and 4-sulphated residues in the chondroitin sulphate linkage region observed by high-pH anion-exchange chromatography

2000 ◽  
Vol 347 (2) ◽  
pp. 339-348 ◽  
Author(s):  
Robert M. LAUDER ◽  
Thomas N. HUCKERBY ◽  
Ian A. NIEDUSZYNSKI
Keyword(s):  
Articular Cartilage ◽  
Anion Exchange ◽  
Chondroitin Sulphate ◽  
Basic Structure ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
High Ph ◽  
Tracheal Cartilage ◽  
Bovine Articular Cartilage ◽  
Linkage Region

We report the isolation, characterization and quantification of five octasaccharides, four hexasaccharides and two tetrasaccharides, derived from the chondroitin sulphate (CS) linkage region of 6-8-year-old bovine articular cartilage aggrecan, following digestion with chondroitin ABC endolyase. Using a novel high-pH anion-exchange chromatography (HPAEC) method, in conjunction with one- and two-dimensional 1H-NMR spectroscopy, we have identified the following basic structure for the CS linkage region of aggrecan: ∆UA(β1-3)GalNAc[0S/4S/6S](β1-4)GlcA(β1-3)GalNAc[0S/4S/6S](β1-4)GlcA(β1-3)Gal[0S/6S](β1-3)Gal(β1-4)Xyl, where ∆UA represents 4,5-unsaturated hexuronic acid, and 4S and 6S represent an O-ester sulphate group on C-4 and C-6 respectively. The octa-, hexa- and tetra-saccharide linkage region fragments were used to develop a HPAEC fingerprinting method, with detection at A232 nm, and a linear response to approx. 0.1 nmol of substance. The sulphation patterns of CS linkage regions, of up to octasaccharide in size, from articular and tracheal cartilage aggrecan were examined. The results show that in articular cartilage, for the majority (53%) of octasaccharides the 2-deoxy-2-N-acetyl amino-D-galactose (GalNAc) residues closest to the linkage region are both 6-sulphated; however, in a significant portion (34%), one or more of these GalNAc residues are unsulphated, and in 8% both are unsulphated. Approximately 10-18% of the chains have a 4-sulphated GalNAc in the first disaccharide, and 12% have a sulphated linkage region Gal residue. No evidence was found for uronic acid sulphation. These data show that there is a significant increase in the incidence of unsulphated and 4-sulphated GalNAc residues adjacent to the linkage region compared with the rest of the chain. Bovine tracheal cartilage linkage regions displayed very similar sulphation profiles to those from articular cartilage, despite the presence of a higher level of GalNAc 4-sulphation within the repeat region of the main CS chain.

scholarly journals Age-related changes in the structure of the keratan sulphate chains attached to fibromodulin isolated from articular cartilage

1998 ◽  
Vol 330 (2) ◽  
pp. 753-757 ◽  
Author(s):  
M. Robert LAUDER ◽  
N. Thomas HUCKERBY ◽  
A. Ian NIEDUSZYNSKI ◽  
H. K. Anna PLAAS
Keyword(s):  
Articular Cartilage ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Keratan Sulphate ◽  
Bovine Articular Cartilage ◽  
Acetylneuraminic Acid ◽  
Age Related ◽  
Keratanase Ii ◽  
Age Related Changes ◽  
Related Increase

Bovine articular cartilage fibromodulin has been isolated from animals aged 3 months to 8 years, and the attached keratan sulphate (KS) chains digested with keratanase II. The oligosaccharides generated have been reduced, examined by high-pH anion-exchange chromatography and their structures identified by comparison with standards. It has been shown that in fibromodulin from young articular cartilage, the KS chains do not possess either non-reducing terminal (α2-6)-linked N-acetylneuraminic acid or fucose (α1-3)-linked to sulphated N-acetylglucosamine residues. However, an age-related increase has been observed in the abundance of both (α2-6)-linked N-acetylneuraminic acid and (α1-3)-linked fucose, neither of which is found in KS isolated from non-articular cartilage, irrespective of the age of the source. Interestingly, the KS chain length remains constant as a function of age, which possibly relates to a role in collagen fibril assembly. In addition, no significant age-related changes were identified in levels of galactose sulphation.

Age-related Changes in the Antigenicity of Human Articular Cartilage Proteoglycans

1982 ◽  
Vol 2 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Brian R. Champion ◽  
Agnes Reiner ◽  
Peter J. Roughley ◽  
A. Robin Poole
Keyword(s):  
Articular Cartilage ◽  
Human Articular Cartilage ◽  
Age Related ◽  
Cartilage Proteoglycans ◽  
Age Related Changes

scholarly journals Age-related changes in the synthesis of link protein and aggrecan in human articular cartilage: implications for aggregate stability

1998 ◽  
Vol 337 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Mark C. BOLTON ◽  
Jayesh DUDHIA ◽  
Michael T. BAYLISS
Keyword(s):  
Articular Cartilage ◽  
De Novo ◽  
Core Protein ◽  
Buoyant Density ◽  
Aggregate Stability ◽  
Exchange Chromatography ◽  
Human Articular Cartilage ◽  
Post Translational Modification ◽  
Link Protein ◽  
Age Related

The rates of incorporation of radiolabelled leucine into aggrecan and link protein have been measured in human articular cartilage of different ages. Aggrecan and link protein were purified in the A1 fraction of CsCl gradients as a result of their ability to form high-buoyant-density proteoglycan aggregates with hyaluronic acid. Separation of the aggrecan from the link protein was achieved by Mono Q anion-exchange chromatography. The rates of synthesis of both aggrecan and link protein decreased with age. The age-related decrease in synthesis of aggrecan was paralleled by a decrease in the rate of sulphate incorporation into glycosaminoglycan chains. The synthesis of link protein decreased with age to a greater extent than that of aggrecan such that the ratio of the rates of link protein to aggrecan synthesis decreased from 1 in immature cartilage to 0.2 in mature cartilage. The age-related decrease in link protein synthesis is controlled at least in part by transcriptional or post-trancriptional mechanisms, as shown by the accompanying age-related decrease in link-protein mRNA. The absence of any age-related decrease in aggrecan mRNA suggests that the decrease in synthesis of aggrecan core protein is controlled by a translational mechanism. Measurement of the total tissue content of aggrecan and link protein by radioimmunoassay revealed an age-related increase in the accumulation of these matrix proteins, even though their de novo synthesis was decreasing. This illustrates the importance that the regulation of extracellular post-translational modification also has in controlling the overall turnover of the cartilage matrix.

scholarly journals Quantification of aggrecan and link-protein mRNA in human articular cartilage of different ages by competitive reverse transcriptase-PCR

1996 ◽  
Vol 319 (2) ◽  
pp. 489-498 ◽  
Author(s):  
Mark C BOLTON ◽  
Jayesh DUDHIA ◽  
Michael T BAYLISS
Keyword(s):  
Articular Cartilage ◽  
Reverse Transcriptase ◽  
Mrna Expression ◽  
Northern Hybridization ◽  
Human Articular Cartilage ◽  
Rt Pcr ◽  
Link Protein ◽  
Reverse Transcriptase Pcr ◽  
Age Related ◽  
Age Related Changes

A competitive reverse transcriptase–PCR (RT-PCR) assay has been developed for the quantification of particular mRNA species in human articular cartilage. Competitor RNA species were synthesized that differed from the amplified target sequence only by the central insertion of an EcoRI restriction site. By using known amounts of synthetic target and competitor RNA, it was shown that competitor RNA molecules designed in this way are reverse-transcribed and amplified with equal efficiency to the target of interest. Furthermore quantification could be performed during the plateau phase of the PCR, which was necessary when using ethidium bromide fluorescence as a detection system. The inhibition of aggrecan and link-protein mRNA expression by interleukin 1 or tumour necrosis factor in monolayers of human articular chondrocytes quantified by this competitive RT-PCR method compared favourably with Northern hybridization studies. The main advantage of this technique is that it can be used to quantify levels of mRNA with RNA extracted directly from 100 mg wet weight of human articular cartilage. Age-related changes in aggrecan and link-protein mRNA were therefore quantified in human articular cartilage directly after dissection from the joint. The concentration of link-protein mRNA was higher in immature cartilage than in mature cartilage when expressed relative to the amount of glyceraldehyde-3-phosphate dehydrogenase mRNA, but no age-related changes were observed in aggrecan mRNA expression. The ratio of aggrecan to link-protein mRNA was higher in mature cartilage than in immature tissue. These age-related differences in the molecular stoichiometry of aggrecan and link-protein mRNA might have implications with respect to the regulation of the formation and the stability of the proteoglycan aggregates in cartilage.

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