Proteoglycan Metabolism In Articular Cartilage Research Articles

Glucosamine reduces the inhibition of proteoglycan metabolism caused by local anaesthetic solution in human articular cartilage: an in vitro study

BackgroundWe assessed whether local anaesthetics caused inhibition of proteoglycan metabolism in human articular cartilage and whether the addition of Glucosamine sulphate could prevent or allow recovery from this adverse effect on articular cartilage metabolism.MethodsCartilage explants obtained from 13 femoral heads from fracture neck of femur patients (average age 80 years, 10 female) were exposed to either 1% Lidocaine, 2% Lidocaine, 0.25% Bupivacaine, 0.5% Bupivacaine, 0.5% Levo-bupivacaine or a control solution (M199 culture medium). Glucosamine-6-Sulphate was added during or 1 h after exposure to 0.5% Bupivacaine to assess its protective and reparative effects. After exposure, the explants were incubated in culture medium containing radio labelled 35-sulphate and uptake was measured after 16 h to give an assessment of proteoglycan metabolism.ResultsThe reduction in 35-S uptake compared to control was 65% for 1% Lidocaine (p < 0.001), 79% for 2% Lidocaine (p < 0.001), 61% for 0.25% Bupivacaine (p < 0.001), 85% for 0.5% Bupivacaine (p < 0.001) and 77% for 0.5% Levobupivacaine (p < 0.001). Glucosamine was able to protect the articular cartilage by reducing the inhibition of proteoglycan metabolism of 0.5% Bupivacaine from 85 to 30% (p < 0.001). When added after 0.5% Bupivacaine exposure, Glucosamine allowed some recovery with inhibition of metabolism to 70% (p = 0.004).ConclusionOur results showed that all local anaesthetic solutions inhibited proteoglycan metabolism in articular cartilage and the addition of Glucosamine was able to reduce the inhibition of metabolism caused by 0.5% Bupivacaine. Intra-articular injection of local anaesthetics requires careful consideration of risks and benefits.

Effect of Different Irrigation Fluids on Human Articular Cartilage: An In Vitro Study

The goal of this study was to examine the effect of different irrigation fluids on human articular cartilage. Femoral heads were obtained from 9 patients with fractured neck of femur (mean age, 89 years; 7 female) and tibial plateaus from 2 female patients at the time of total knee replacement (mean age, 73 years). Chrondral explants were harvested and exposed to 1 of 4 different irrigation fluids for 1 hour: Ringer's solution, normal saline (0.9% NaCl), 1.5% glycine, or 5% mannitol. M199 culture medium was used as a positive control, and 0.5% bupivicaine, previously shown to be harmful to articular cartilage, as a negative control. After exposure, explants were incubated with radiolabeled sulfate ((35)S0(4)), and uptake was measured after 16 hours as an indicator of proteoglycan synthesis. (35)S0(4) uptake was inhibited 10% by Ringer's solution (P= .3), 24% by 1.5% glycine (P= .08), 31% by 5% mannitol (P= .03), 35% by normal saline (P= .04), and 90% by 0.5% bupivacaine (P < .001), compared with the M199 control. Comparisons of the different solutions showed that all solutions were less inhibitory than 0.5% bupivacaine (P < .001). The only significant difference was that between normal saline and Ringer's solution (P= .03). In an in vitro model of human articular cartilage, Ringer's solution had the least effect on cartilage metabolism, and normal saline caused the greatest inhibition of cartilage metabolism. Normal saline, the most commonly used irrigation fluid, may have an inhibitory effect on proteoglycan metabolism in articular cartilage. Additional studies are required to assess the potential damage to cartilage from normal saline in the clinical setting.

The proteoglycan metabolism of articular cartilage in joint-scale culture.

Understanding and controlling chondrocyte and cartilage metabolism in osteochondral tissues may facilitate ex vivo maintenance and application, both for allografts and tissue-engineered grafts. The hypothesis of this study was that maintenance of chondrocyte viability and matrix content and release of sulfated glycosaminoglycan (sGAG) in the articular cartilage of joint-scale osteochondral fragments are temperature and metabolism dependent. The aims were to assess, for adult goat joints, the effects of incubation temperature (37 degrees C vs. 4 degrees C) on cartilage chondrocyte viability and tissue matrix content and mechanical function, and the effects of temperature and cellular biosynthesis on sGAG release. Chondrocyte viability was maintained with 37 degrees C incubation for 28 days, but decreased by approximately 30% with 4 degrees C incubation. Concomitantly, with 37 degrees C incubation, cartilage sGAG was depleted by approximately 52% with the lost sGAG predominantly unable to aggregate with hyaluronan, whereas collagen content, tissue thickness, and tissue stiffness were maintained. The depletion of sGAG was diminished by slowing metabolism, with 4 degrees C decreasing release by approximately 79% compared with 37 degrees C incubation, and cycloheximide inhibition of cell metabolism at 37 degrees C decreasing release by approximately 47%. These results indicate that the articular cartilage of joint-scale grafts have enhanced chondrocyte viability with incubation at 37 degrees C, but may need anabolic stimuli or catabolic inhibitors to maintain sGAG content.

Effect of heat stimulation on viability and proteoglycan metabolism ofcultured chondrocytes: preliminary report

Thermotherapy has been applied to various joint diseases and injuries, but its direct effects on articular cartilage have remained unclear. The present study examined the effects on cell viability and metabolism by using the chondrocyte-like cell line HCS-2/8. The temperatures and durations of heat stimulation were 39°, 41°, 43°, and 45°C for 15 or 30min. After heat stimulation of 41°C or lower for 15 or 30 min, cell viability increased and proteoglycan metabolism was accelerated, whereas after stimulation at 43°C or higher for 30min the viability and metabolism decreased. These results indicate that appropriate heat stimulation positively affects cell viability and the proteoglycan metabolism of articular cartilage, whereas too much heat stimulation produces negative effects. Clinical efficacy is therefore determined by the overall thermal dose. When the appropriate combination of temperature and duration is found, thermotherapy for diseases and injury of articular cartilage can be highly useful in clinical practice.

Recombinant equine growth hormone administration: effects on synovial fluid biomarkers and cartilage metabolism in horses.

Recombinant equine growth hormone (reGH) has recently been evaluated for effects on body condition and wound healing. It has the potential to influence articular cartilage via stimulation of IGF-1. To investigate effects of administration on synovial joint metabolism. Six mature horses were given 20 microg/kg bwt reGH daily for 8 weeks by i.m. injection. Three control horses were injected with sterile water. Serum and synovial fluid samples were collected at 6, 8, 11 and 16 weeks for GH and IGF-1 assays. Articular cartilage harvested at week 16 was evaluated by Western analysis using monoclonal antibodies BC-13, BC-4, 8-A-4 and CH-3. Concentrations of IGF-1 in serum and synovial fluid were significantly elevated (P < 0.05) at 6 and 8 weeks in the reGH group. Glycosaminoglycan concentrations in synovial fluid were significantly less than controls at these time points, suggesting that reGH may modulate proteoglycan metabolism in articular cartilage. In the reGH group, there were not any alterations in synovial fluid content of 3B3(-) epitope or aggrecan metabolite, or in aggrecan or link protein catabolites retained within cartilage, that might be expected with development of osteoarthritis. Intramuscular administration of reGH may be a more efficient means of delivery of IGF-1 to joints for cartilage resurfacing initiatives. We found no alterations in cartilage metabolism indicative of development of osteoarthritis.

The effects of methylprednisolone on normal and monocyte-conditioned medium-treated articular cartilage from dogs and horses.

To study in vitro (1) the dose-response relationships between proteoglycan metabolism in normal and corticosteroid-treated articular cartilage; (2) long-term proteoglycan metabolism after treatment of articular cartilage with corticosteroids; and (3) the effect of corticosteroids on proteoglycan metabolism in articular cartilage treated with monocyte-conditioned medium (MCM). Equine and canine articular cartilage explants were treated with corticosteroids and MCM. Proteoglycan synthesis and degradation were measured by radioactive labeling in short-term culture, and the long-term effect of corticosteroid treatment on proteoglycan metabolism was studied in normal explants. Two young cross-breed horses and 3 young Labrador retrievers. Equine articular cartilage explants were incubated in medium containing methylprednisolone sodium succinate (MPS) at 0, .001, .01, .1, 1, and 10 mg/mL (final concentration) for 1 day and then in fresh medium without MPS. Proteoglycan synthesis was measured by incorporation of sodium [35S]sulfate at 1, 3, 7, 10, and 13 days after initial treatment with MPS. Proteoglycan release was measured from separate explants prelabeled with sodium [35S]sulfate and treated similarly. Equine articular cartilage explants were treated with equine MCM simultaneously with, and 24 hours before MPS, at 0, 0.01, 0.1, 1, or 5 mg/mL for 72 hours. Proteoglycan synthesis and degradation in these explants was compared. Proteoglycan synthesis and degradation were measured similarly in canine articular cartilage explants treated simultaneously with canine MCM and MPS at 0, 0.001, 0.01, 0.1, 1 and 10 mg/mL for 72 hours. Equine articular cartilage explants treated with 0, 0.01, 0.1, 1, and 5 mg/mL of MPS for 72 hours were evaluated histologically. Proteoglycan synthesis in normal equine articular cartilage was severely depressed by 10 mg/mL MPS for 24 hours, and proteoglycan synthesis failed to recover after 13 days of culture in medium without MPS. Cartilage treated with 5 mg/mL MPS had pyknotic chondrocyte nuclei and empty lacunae. Concentrations of 1 and 0.1 mg/mL MPS depressed proteoglycan synthesis in normal equine cartilage explants. For these 2 concentrations, proteoglycan synthesis recovered 2 days after MPS removal and increased significantly (P < .05) 7 days after treatment with MPS compared with controls without MPS. Concentrations of 0.001 and 0.01 mg/mL MPS did not significantly affect proteoglycan synthesis in normal equine cartilage explants. Cumulative proteoglycan loss over 13 days in culture from normal equine explants treated for 24 hours with different concentrations of MPS was not significantly different between treatment groups at any time point. MCM significantly depressed proteoglycan synthesis in both canine and equine articular cartilage explants and significantly increased proteoglycan release. These effects were prevented in the canine explants by simultaneous treatment with MPS at 1 and 0.1 mg/mL, and proteoglycan release induced by MCM in equine articular cartilage was inhibited by 1 mg/mL MPS. Concentrations of 1.0 and 0.1 mg/mL MPS alleviated articular cartilage degradation in MCM-treated articular cartilage in vitro. These concentrations of MPS in contact with normal cartilage explants for 24 hours are unlikely to be detrimental in the long term to proteoglycan synthesis. The response of articular cartilage to MPS was affected by treatment with MCM so that results of experiments with normal articular cartilage explants may not reflect results obtained with abnormal cartilage. It may be possible to find an intraarticular concentration of corticosteroid that protects articular cartilage against cytokine-induced matrix degradation yet not have prolonged or permanent detrimental effects on chondrocyte matrix synthesis.

EFFECTS OF INTERLEUKIN-6 ON PROLIFERATION AND PROTEOGLYCAN METABOLISM IN ARTICULAR CHONDROCYTE CULTURES

Interleukin-6 (IL-6) levels are markedly increased in the synovial fluid of patients with rheumatoid arthritis or osteoarthritis. However, the effects of IL-6 on proliferation and proteoglycan metabolism in articular cartilage are not known. We demonstrated here the effects of human recombinant (hr) IL-6 on proliferation and proteoglycan metabolism in rabbit articular chondrocyte cultures.In vitro, these cells proliferated and produced abundant extracellular matrices. We found that 1–10ng/ml of hrIL-6 inhibited proliferation to approximately 65% of control levels and suppressed colony formation induced by bFGF in soft agarose. The same concentration of hrIL-6 depressed proteoglycan synthesis to approximately 60% of control levels. Moreover, hrIL-6 significantly enhanced proteoglycan degradation induced by hrIL-1β, although hrIL-6 alone did not affect proteoglycan degradation. These findings suggest that IL-6 is a negative regulator for chondrocyte proliferation and articular cartilage metabolism.

Effects of copper and zinc on proteoglycan metabolism in articular cartilage

Co-Cultures of porcine articular cartilage and synovium or synovial conditioned medium were used as an in vitro model to mimic inflammatory events at the cartilage/synovial junction in degenerative joint disease. This model provides a useful tool to assess the anti-inflammatory and antiarthritic properties of pharmacological agents. In this study the effects of copper and zinc on (i) PG synthesis by cartilage and (ii) synovial-induced PG depletion have been investigated. Copper sulphate at a concentration of 0.01 mM did not stimulate PG synthesis significantly in cultured cartilage explants but completely abrogated the inhibitory effects of synovial tissue in co-culture experiments. This finding was supported by the histological demonstration of copper-dependent reversal of the PG depletion in cartilage exposed to synovial conditioned medium. Zinc sulphate at 0.01 mM had no effect on PG synthesis and was unable to protect cartilage against synovialinduced PG depletion. These results reveal possible mechanisms by which copper exerts its anti-inflammatory and anti-arthritic actions.

Factors involved in the regulation of proteoglycan metabolism in articular cartilage.

Arthritis & RheumatismVolume 32, Issue 10 p. 1197-1201 Current CommentFree to Read Factors involved in the regulation of proteoglycan metabolism in articular cartilage Teresa I. Morales PhD, Corresponding Author Teresa I. Morales PhD Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MarylandNational Institute of Dental Research, NIH, Building 30, Room 109, Bethesda, MD 20892Search for more papers by this authorVincent C. Hascall, Vincent C. Hascall Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MarylandSearch for more papers by this author Teresa I. Morales PhD, Corresponding Author Teresa I. Morales PhD Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MarylandNational Institute of Dental Research, NIH, Building 30, Room 109, Bethesda, MD 20892Search for more papers by this authorVincent C. Hascall, Vincent C. Hascall Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MarylandSearch for more papers by this author First published: October 1989 https://doi.org/10.1002/anr.1780321003Citations: 68AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume32, Issue10October 1989Pages 1197-1201 RelatedInformation

Effects of nonsteroidal anti-inflammatory drugs on chondrocyte metabolism in vitro and in vivo

Salicylates and several other nonsteroidal anti-inflammatory drugs (NSAIDs) that are commonly employed in the treatment of osteoarthritis effectively decrease joint pain and increase mobility. Results from in vitro studies indicate that, in addition, some of these compounds affect proteoglycan metabolism of articular cartilage. Data from in vivo studies suggest that salicylate administration may accelerate articular cartilage damage in several animal models of osteoarthritis. At in vitro concentrations comparable to those that are achieved in the synovial fluid of patients treated with the drug, several NSAIDs suppress proteoglycan synthesis by the chondrocyte. Salicylate has been shown to inhibit the enzymes involved in the early stages of chondroitin sulfate biosynthesis. These NSAIDrelated effects on chondrocyte metabolism appear unrelated to inhibition of prostaglandin synthetase, and are much more profound in osteoarthritic cartilage than in normal cartilage, due to enhanced uptake of NSAIDs by the osteoarthritic cartilage. Depletion of matrix proteoglycans appears to be a major factor in the increased vulnerability of chondrocytes in degenerating cartilage to effects of NSAIDs. Some NSAIDs may be bound to matrix components. If similar changes occur in the cartilage of patients with arthritis treated with NSAIDs, despite the symptomatic improvement that these drugs produce, cartilage degeneration could be accelerated.

Sulfate metabolism in human chondrocyte cultures.

The depletion of articular cartilage in the afflicted joints is a primary clinical feature of osteoarthritis. This disorder has been linked to a disturbance in the metabolism of the extracellular matrix components of this tissue. The mechanisms involved in the regulation of sulfated proteoglycan metabolism in articular cartilage were therefore studied by measuring the biosynthesis and distribution of (35)S-labeled glycosaminoglycans in chondrocyte cultures derived from normal and osteoarthritic tissue. Incorporation experiments were carried out at pH 7.0 with [(35)S]Na(2)SO(4) in the presence of fetal calf serum, human serum from normal or arthritic individuals, or a combination of these. In the presence of heat-inactivated human sera, osteoarthritic chondrocytes incorporate about two times as much of the available sulfate into macromolecules as do normal chondrocytes. The deposition of newly synthesized sulfated macromolecules into the cell layer by these cells is lower, however, than that by normal cells. In cultures of normal human chondrocytes, noninactivated sera from individuals with osteoarthritis stimulate proteoglycan biosynthesis more than equal concentrations of normal sera. The fraction of the newly synthesized material deposited into the cell layer was found to decrease with increasing serum concentrations. In the absence of serum, a 5- to 10-fold increase in deposited sulfated macromolecules was found. The distribution within the cell layer between intra- and extracellular sites also was monitored by serum factors. Heat inactivation of the human serum component of the medium resulted in a 50% decrease in intracellular retention. These data suggest that biosynthesis of sulfated proteoglycans and their retention in the matrix are modulated by cell and serum factors. Despite and increased uptake of radioactively labeled inorganic sulfate by osteoarthritic chondrocytes in cell culture, a lower rate of deposition into the cell layer resulted in less matrix formation. This may be representative of the process leading to cartilage degradation in degenerative joint disease in vivo.