Glycosaminoglycans modulate inflammation and apoptosis in LPS-treated chondrocytes
ABSTRACT Previous studies reported that hyaluronic acid (HA), chondroitin sulphate (CS) and heparan sulphate (HS) were able to reduce the inflammatory process in a variety of cell types after lipopolysaccharide (LPS) stimulation. The aim of this study was to investigate the anti-inflammatory effect of glycosaminoglycans (GAGs) in mouse articular chondrocytes stimulated with LPS. Chondrocyte treatment with LPS (50 microg/ml) generated high levels of TNF-alpha, IL-1beta, IL-6, IFN-gamma, MMP-1, MMP-13, iNOS gene expression and their related proteins, increased NO concentrations (evaluated in terms of nitrites formation), NF-kappaB activation and IkBalpha degradation as well as apoptosis evaluated by the increase in caspase-3 expression and the amount of its related protein. The treatment of chondrocytes using two different doses (0.5 and 1.0 mg/ml) of HA, chondroitin-4-sulphate (C4S), chondroitin-6-sulphate (C6S), HS, keratan sulphate (KS) and dermatan sulphate (DS) produced a number of effects. HA exerted a very small anti-inflammatory and anti-apoptotic effect while it significantly reduced NO levels, although the effect on iNOS expression and activity was extremely slight. C4S and C6S reduced inflammation mediators and the apoptotic process. C6S failed to decrease NO production, although iNOS expression and activity were significantly reduced. HS, like C4S, was able to reduce all the effects stimulated by LPS treatment. KS and DS produced no reduction in any of the parameters considered. These results give further support to the hypothesis that GAGs actively participate in the regulation of inflammatory and apoptotic processes.
- SourceAvailable from: PubMed Central[Show abstract] [Hide abstract]
ABSTRACT: Osteoarthritis (OA) is a degenerative joint disease that is characterized by increasing loss of cartilage, remodeling of the periarticular bone, and inflammation of the synovial membrane. Besides the common OA therapy with nonsteroidal anti-inflammatory drugs (NSAIDs), the treatment with chondroprotectives, such as glucosamine sulfate, chondroitin sulfate, hyaluronic acid, collagen hydrolysate, or nutrients, such as antioxidants and omega-3 fatty acids is a promising therapeutic approach. Numerous clinical studies have demonstrated that the targeted administration of selected micronutrients leads to a more effective reduction of OA symptoms, with less adverse events. Their chondroprotective action can be explained by a dual mechanism: (1) as basic components of cartilage and synovial fluid, they stimulate the anabolic process of the cartilage metabolism; (2) their anti-inflammatory action can delay many inflammation-induced catabolic processes in the cartilage. These two mechanisms are able to slow the progression of cartilage destruction and may help to regenerate the joint structure, leading to reduced pain and increased mobility of the affected joint.International Journal of Rheumatology 08/2011; 2011:969012. DOI:10.1155/2011/969012
- [Show abstract] [Hide abstract]
ABSTRACT: The glycosaminoglycan chondroitin sulfate (CS) is a major constituent of the extracellular matrix of the central nervous system where it can constitute part of the perineuronal nets. Constituents of the perineuronal nets are gaining interest because they have modulatory actions on their neighbouring neurons. In this study we have investigated if CS could afford protection in an acute in vitro ischemia/reoxygenation model by using isolated hippocampal slices subjected to 60min oxygen and glucose deprivation (OGD) followed by 120min reoxygenation (OGD/Reox). In this toxicity model, CS afforded protection of rat hippocampal slices measured as a reduction of lactate dehydrogenase (LDH) release; maximum protection (70% reduction of LDH) was obtained at the concentration of 3mM. To evaluate the intracellular signaling pathways implicated in the protective effect of CS, we first analysed the participation of the mitogen-activated protein kinases (MAPKs) p38 and ERK1/2 by western blot. OGD/Reox induced the phosphorylation of p38 and dephosphorylation of ERK1/2; however, CS only inhibited p38 but had no effect on ERK1/2. Furthermore, OGD/Reox-induced translocation of p65 to the nucleus was prevented in CS treated hippocampal slices. Finally, CS inhibited iNOS induction caused by OGD/Reox and thereby nitric oxide (NO) production measured as a reduction in DAF-2 DA fluorescence. In conclusion, the protective effect of CS in hippocampal slices subjected to OGD/Reox can be related to a modulatory action of the local immune response by a mechanism that implies inhibition of p38, NFκB, iNOS and the production of NO.Neurochemistry International 02/2011; 58(6):676-83. DOI:10.1016/j.neuint.2011.02.006 · 2.65 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Chondroitin sulfate (CS) is recommended as a therapeutic intervention in the multimodal approach of osteoarthritis (OA) management. CS has been studied extensively to describe its pharmacology (pharmacokinetic, in vitro and in vivo effects) and its clinical efficacy. Various results have been reported depending on the system of evaluation (model, dosage and duration) and the source of CS (origin and quality). The purpose of this review was to gather most of the available information about CS and to discuss its potency in OA management.Therapeutic advances in musculoskeletal disease 12/2010; 2(6):335-48. DOI:10.1177/1759720X10383076