scholarly journals Age-related decrease in the link-stability of proteoglycan aggregates formed by articular chondrocytes

1984 ◽  
Vol 220 (1) ◽  
pp. 337-340 ◽  
Author(s):  
A H K Plaas ◽  
J D Sandy
Keyword(s):  
Protein Synthesis ◽  
Articular Cartilage ◽  
Proliferative Activity ◽  
Monolayer Culture ◽  
Articular Chondrocytes ◽  
Link Protein ◽  
Age Related ◽  
Link Stability ◽  
Proteoglycan Aggregates

Chondrocytes were isolated from the articular cartilage of rabbits aged between 6 and 50 weeks and labelled with [35S]sulphate after 48 h in monolayer culture. The percentage of the total proteoglycan monomers synthesized by each culture that were present as link-stabilized aggregates was shown to be about 83% at 6, 9 and 12 weeks, 73% at 15 weeks, 48% at 30 weeks and 32% at 50 weeks. The proliferative activity of the cells in culture also decreased markedly with the age of the donor. The results suggest that aging of chondrocytes in vivo is accompanied by a decrease in their capacity for link-protein synthesis.

scholarly journals The Effects of Age and Cell Isolation on Collagen II Synthesis by Articular Chondrocytes: Evidence for Transcriptional and Posttranscriptional Regulation

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Vipin Asopa ◽  
Tonia Vincent ◽  
Jeremy Saklatvala
Keyword(s):  
Protein Synthesis ◽  
Articular Cartilage ◽  
Mrna Stability ◽  
Articular Chondrocytes ◽  
Cartilage Regeneration ◽  
Type Ii Collagen ◽  
Systematic Investigation ◽  
Mrna Levels ◽  
Age Related ◽  
Collagen Ii

Adult articular cartilage synthesises very little type II collagen in comparison to young cartilage. The age-related difference in collagen II synthesis is poorly understood. This is the first systematic investigation of age-related differences in extracellular matrix synthesis in fresh articular cartilage and following isolation of chondrocytes. A histological comparison of 3-year-old skeletally mature and 6-month-old juvenile porcine cartilage was made. Differences in collagen II, aggrecan, and Sox5, 6, and 9 mRNA and protein expression and mRNA stability were measured. Adult cartilage was found to be thinner than juvenile cartilage but with similar chondrocyte density. Procollagen α1(II) and Sox9 mRNA levels were 10-fold and 3-fold reduced in adult cartilage. Sox9 protein was halved and collagen II protein synthesis was almost undetectable and calculated to be at least 30-fold reduced. Aggrecan expression did not differ. Isolation of chondrocytes caused a drop in procollagen α1(II) and Sox9 mRNA in both adult and juvenile cells along with a marked reduction in Sox9 mRNA stability. Interestingly, juvenile chondrocytes continued to synthesise collagen II protein with mRNA levels similar to those seen in adult articular cartilage. Age-related differences in collagen II protein synthesis are due to both transcriptional and posttranscription regulation. A better understanding of these regulatory mechanisms would be an important step in improving current cartilage regeneration techniques.

scholarly journals Age-related changes in the composition, the molecular stoichiometry and the stability of proteoglycan aggregates extracted from human articular cartilage

2003 ◽  
Vol 370 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Terri WELLS ◽  
Catherine DAVIDSON ◽  
Matthias MÖRGELIN ◽  
Joseph L.E. BIRD ◽  
Michael T. BAYLISS ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Chloride Concentration ◽  
Human Articular Cartilage ◽  
Guanidinium Chloride ◽  
Link Protein ◽  
Molar Ratios ◽  
Age Related ◽  
Proteoglycan Aggregates ◽  
High Concentrations ◽  
The Stability

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 (1M, 2M, 3M and 4M). 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 1M 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.

Facilitating In Vivo Articular Cartilage Repair by Tissue-Engineered Cartilage Grafts Produced From Auricular Chondrocytes

2017 ◽  
Vol 46 (3) ◽  
pp. 713-727 ◽  
Author(s):  
Chin-Chean Wong ◽  
Chih-Hwa Chen ◽  
Li-Hsuan Chiu ◽  
Yang-Hwei Tsuang ◽  
Meng-Yi Bai ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Articular Cartilage ◽  
Cartilage Repair ◽  
Articular Chondrocytes ◽  
Type Ii Collagen ◽  
Type Ii ◽  
Articular Cartilage Repair ◽  
3 Dimensional ◽  
Cell Conversion

Background: Insufficient cell numbers still present a challenge for articular cartilage repair. Converting heterotopic auricular chondrocytes by extracellular matrix may be the solution. Hypothesis: Specific extracellular matrix may convert the phenotype of auricular chondrocytes toward articular cartilage for repair. Study Design: Controlled laboratory study. Methods: For in vitro study, rabbit auricular chondrocytes were cultured in monolayer for several passages until reaching status of dedifferentiation. Later, they were transferred to chondrogenic type II collagen (Col II)–coated plates for further cell conversion. Articular chondrogenic profiles, such as glycosaminoglycan deposition, articular chondrogenic gene, and protein expression, were evaluated after 14-day cultivation. Furthermore, 3-dimensional constructs were fabricated using Col II hydrogel-associated auricular chondrocytes, and their histological and biomechanical properties were analyzed. For in vivo study, focal osteochondral defects were created in the rabbit knee joints, and auricular Col II constructs were implanted for repair. Results: The auricular chondrocytes converted by a 2-step protocol expressed specific profiles of chondrogenic molecules associated with articular chondrocytes. The histological and biomechanical features of converted auricular chondrocytes became similar to those of articular chondrocytes when cultivated with Col II 3-dimensional scaffolds. In an in vivo animal model of osteochondral defects, the treated group (auricular Col II) showed better cartilage repair than did the control groups (sham, auricular cells, and Col II). Histological analyses revealed that cartilage repair was achieved in the treated groups with abundant type II collagen and glycosaminoglycans syntheses rather than elastin expression. Conclusion: The study confirmed the feasibility of applying heterotopic chondrocytes for cartilage repair via extracellular matrix–induced cell conversion. Clinical Relevance: This study proposes a feasible methodology to convert heterotopic auricular chondrocytes for articular cartilage repair, which may serve as potential alternative sources for cartilage repair.

Regulation of the chondrocyte phenotype by β-catenin

Development ◽  
2002 ◽  
Vol 129 (23) ◽  
pp. 5541-5550
Author(s):  
Je-Hwang Ryu ◽  
Song-Ja Kim ◽  
Seon-Hee Kim ◽  
Chun-Do Oh ◽  
Sang-Gu Hwang ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Monolayer Culture ◽  
Nuclear Translocation ◽  
Articular Chondrocytes ◽  
Glycogen Synthase ◽  
Ectopic Expression ◽  
Activator Protein 1 ◽  
Chondrocyte Phenotype

β-Catenin regulates important biological processes, including embryonic development and tumorigenesis. We have investigated the role ofβ-catenin in the regulation of the chondrocyte phenotype. Expression ofβ-catenin was high in prechondrogenic mesenchymal cells, but significantly decreased in differentiated chondrocytes both in vivo and in vitro. Accumulation of β-catenin by the inhibition of glycogen synthase kinase-3β with LiCl inhibited chondrogenesis by stabilizing cell-cell adhesion. Conversely, the low level of β-catenin in differentiated articular chondrocytes was increased by post-translational stabilization during phenotypic loss caused by a serial monolayer culture or exposure to retinoic acid or interleukin-1β. Ectopic expression of β-catenin or inhibition of β-catenin degradation with LiCl or proteasome inhibitor caused de-differentiation of chondrocytes. Transcriptional activation ofβ-catenin by its nuclear translocation was sufficient to cause phenotypic loss of differentiated chondrocytes. Expression pattern of Jun, a known target gene of β-catenin, is essentially the same as that of β-catenin both in vivo and in vitro suggesting that Jun and possibly activator protein 1 is involved in the β-catenin regulation of the chondrocyte phenotype.

Improved Chondrotoxic Profile of Liposomal Bupivacaine Compared With Standard Bupivacaine After Intra-articular Infiltration in a Porcine Model

2017 ◽  
Vol 46 (1) ◽  
pp. 66-71 ◽  
Author(s):  
K. Aaron Shaw ◽  
Colleen Moreland ◽  
Jeremy Jacobs ◽  
Justin M. Hire ◽  
Richard Topolski ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Articular Chondrocytes ◽  
Management Strategies ◽  
Histologic Examination ◽  
Chondrocyte Viability ◽  
Liposomal Bupivacaine ◽  
Stifle Joint ◽  
Chondrocyte Death

Background: Increasingly, liposomal bupivacaine is being used with multimodal pain management strategies. In vitro investigations have shown decreased chondrotoxicity profiles for liposomal bupivacaine; however, there is no evidence regarding its in vivo effects. Hypothesis/Purpose: This study sought to investigate the in vivo chondrotoxicity of liposomal bupivacaine, hypothesizing that there would be increased chondrocyte viability after exposure to liposomal bupivacaine when compared with standard bupivacaine. Study Design: Controlled laboratory study. Methods: Eight juvenile, female Yorkshire cross piglets underwent a lateral stifle joint injection with either 1.3% liposomal bupivacaine or 0.5% bupivacaine. Injections were performed on one joint per animal with no injection to the contralateral knee, which served as the control. Chondrocyte viability was assessed 1 week after injection with a live-dead staining protocol and histologic examination. Results: Significant chondrocyte death was seen with the live-dead staining in the bupivacaine group (33% nonviable cells) in comparison with liposomal bupivacaine (6.2%) and control (5.8%) groups ( P < .01). However, histologic examination showed no differences in chondral surface integrity, fibrillation, and chondrocyte viability. Conclusion: Liposomal bupivacaine was found to be safe for intra-articular injection in this animal model. Although bupivacaine demonstrated decreased chondrocyte viability on a cellular level, histologically there were no changes. This study highlights the dichotomy between fluorescent staining and histologic appearance of articular chondrocytes in short-term analyses of viability. Clinical Relevance: This study supports the peri-articular application of liposomal bupivacaine in the setting of preserved articular cartilage. A single injection of standard bupivacaine did not produce histologic changes in the articular cartilage.

scholarly journals Ageing and zonal variation in post-translational modification of collagen in normal human articular cartilage: The age-related increase in non-enzymatic glycation affects biomechanical properties of cartilage

1998 ◽  
Vol 330 (1) ◽  
pp. 345-351 ◽  
Author(s):  
Ruud A. BANK ◽  
Michael T. BAYLISS ◽  
Floris P. J. G. LAFEBER ◽  
Alice MAROUDAS ◽  
Johan M. TEKOPPELE
Keyword(s):  
Articular Cartilage ◽  
Articular Surface ◽  
Human Articular Cartilage ◽  
Post Translational Modification ◽  
Collagen Network ◽  
Tissue Remodelling ◽  
Healthy Human ◽  
Age Related

A biomechanical failure of the collagen network is postulated in many hypotheses of the development of osteoarthritis with advancing age. Here we investigate the accumulation of non-enzymatic glycation (NEG) products in healthy human articular cartilage, its relation to tissue remodelling and its role in tissue stiffening. Pentosidine levels were low up to age 20 years, and increased linearly after this age. This indicates extensive tissue remodelling at young age, and slow turnover of collagen after maturity has been reached. The slow remodelling is supported by the finding that enzymatic modifications of collagen (hydroxylysine, hydroxylysylpyridinoline, and lysylpyridinoline) were not related to age. The high remodelling is supported by levels of the crosslink lysylpyridinoline (LP) as a function of distance from the articular surface. LP was highest at the surface in mature cartilage (> 20 years), whereas in young cartilage (< 10 years) the opposite was seen; highest levels were close to the bone. LP levels in cartilage sections at age 14 years are high at the surface and close to the bone, but they are low in the middle region. This indicates that maturation of cartilage in the second decade of life starts in the upper half of the tissue, and occurs last in the tissue close to the bone. The effect of NEG products on instantaneous deformation of cartilage was investigated as a functional of topographical variations in pentosidine levels in vivo and in relation to in vitro induced NEG. Consistently, higher pentosidine levels were associated with a stiffer collagen network. A stiffer and more crosslinked collagen network may become more brittle and more prone to fatigue.

scholarly journals Age-related accumulation of Maillard reaction products in human articular cartilage collagen

2000 ◽  
Vol 350 (2) ◽  
pp. 381-387 ◽  
Author(s):  
Nicole VERZIJL ◽  
Jeroen DEGROOT ◽  
Esther OLDEHINKEL ◽  
Ruud A. BANK ◽  
Suzanne R. THORPE ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Maillard Reaction ◽  
Maillard Reaction Products ◽  
Human Articular Cartilage ◽  
Reaction Products ◽  
Collagen Network ◽  
Acid Modification ◽  
Age Related ◽  
Skin Collagen

Non-enzymic modification of tissue proteins by reducing sugars, the so-called Maillard reaction, is a prominent feature of aging. In articular cartilage, relatively high levels of the advanced glycation end product (AGE) pentosidine accumulate with age. Higher pentosidine levels have been associated with a stiffer collagen network in cartilage. However, even in cartilage, pentosidine levels themselves represent < 1 cross-link per 20 collagen molecules, and as such cannot be expected to contribute substantially to the increase in collagen network stiffness. In the present study, we investigated a broad range of Maillard reaction products in cartilage collagen in order to determine whether pentosidine serves as an adequate marker for AGE levels. Not only did the well-characterized AGEs pentosidine, Nε-(carboxymethyl)lysine, and Nε-(carboxyethyl)lysine increase with age in cartilage collagen (all P < 0.0001), but also general measures of AGE cross-linking, such as browning and fluorescence (both P < 0.0001), increased. The levels of these AGEs are all higher in cartilage collagen than in skin collagen. As a functional measure of glycation the digestibility of articular collagen by bacterial collagenase was investigated; digestibility decreased linearly with age, proportional to the extent of glycation. Furthermore, the arginine content and the sum of the hydroxylysine and lysine content of cartilage collagen decrease significantly with age (P < 0.0001 and P < 0.01 respectively), possibly due to modification by the Maillard reaction. The observed relationship between glycation and amino acid modification has not been reported previously in vivo. Our present results indicate that extensive accumulation of a variety of Maillard reaction products occurs in cartilage collagen with age. Altogether our results support the hypothesis that glycation contributes to stiffer and more brittle cartilage with advancing age.

scholarly journals Proteoglycan aggregate formation by articular chondrocytes. Decrease in link-protein synthesis during culture

1983 ◽  
Vol 214 (3) ◽  
pp. 855-864 ◽  
Author(s):  
A H K Plaas ◽  
J D Sandy ◽  
H Muir
Keyword(s):  
Hyaluronic Acid ◽  
Articular Chondrocytes ◽  
Core Protein ◽  
Link Protein ◽  
Monolayer Cultures ◽  
Proteoglycan Aggregates ◽  
Primary Monolayer ◽  
Primary Monolayer Cultures ◽  
Stable Aggregate ◽  
Rabbit Articular Chondrocytes

The synthesis of link-stabilized proteoglycan aggregates by rabbit articular chondrocytes was investigated by [35S]sulphate labelling of primary monolayer cultures maintained for up to 21 days. (1) At all culture times the cells secreted a high-molecular-weight cartilage-type proteoglycan monomer of which 75%-80% formed aggregates with hyaluronic acid. (2) At 2 days of culture all of the aggregates were in link-stabilized form, but by 21 days only 5% were link-stabilized, as shown by displacement of monomers from the aggregate by hyaluronic acid oligosaccharides. (3) The addition of purified link protein to 21-day culture medium increased the proportion of link-stable aggregate from 5% to 70%. (4) Analysis of [3H]serine-labelled proteoglycan aggregates in the medium showed a marked decrease with culture time in the ratio of 3H-labelled link protein to 3H-labelled core protein present. The results suggest that the secretion of proteoglycan monomers and link protein by articular chondrocytes changes independently during prolonged monolayer culture.

scholarly journals Chondroprotective Properties of Human-Enriched Serum Following Polyphenol Extract Absorption: Results from an Exploratory Clinical Trial

Nutrients ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 3071
Author(s):  
Fabien Wauquier ◽  
Elsa Mevel ◽  
Stephanie Krisa ◽  
Tristan Richard ◽  
Josep Valls ◽  
...  
Keyword(s):  
Articular Chondrocytes ◽  
Ex Vivo ◽  
Interleukin 1 ◽  
Clinical Approach ◽  
Age Related ◽  
Nutritional Strategy ◽  
Sparing Effect ◽  
The Relationship

Polyphenols are widely acknowledged for their health benefits, especially for the prevention of inflammatory and age-related diseases. We previously demonstrated that hydroxytyrosol (HT) and procyanidins (PCy), alone or in combination, drive preventive anti-osteoathritic effects in vivo. However, the lack of sufficient clinical evidences on the relationship between dietary phytochemicals and osteoarthritis remains. In this light, we investigated in humans the potential osteoarticular benefit of a grapeseed and olive extract (OPCO) characterized for its hydroxytyrosol (HT) and procyanidins (PCy) content. We first validated, in vitro, the anti-inflammatory and chondroprotective properties of the extract on primary cultured human articular chondrocytes stimulated by interleukin-1 beta (IL-1 β). The sparing effect involved a molecular mechanism dependent on the nuclear transcription factor-kappa B (NF-κB) pathway. To confirm the clinical relevance of such a nutritional strategy, we designed an innovative clinical approach taking into account the metabolites that are formed during the digestion process and that appear in circulation after the ingestion of the OPCO extract. Blood samples from volunteers were collected following ingestion, absorption, and metabolization of the extract and then were processed and applied on human primary chondrocyte cultures. This original ex vivo methodology confirmed at a clinical level the chondroprotective properties previously observed in vitro and in vivo.

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