In vivo effect of opticin deficiency in cartilage in a surgically induced mouse model of osteoarthritis.

The SLRP opticin (OPTC) has been demonstrated to be produced and degraded in osteoarthritic (OA) human cartilage. Here, we investigated the in vivo effect of OPTC deficiency in OA cartilage. OA was induced in 10-week-old Optc -/- and Optc +/+ mice. Ten weeks post-surgery, cartilage was processed for histology and immunohistochemistry. SLRP expression was determined in non-operated mouse cartilage. OA Optc -/- demonstrated significant protection against cartilage degradation. Data revealed that in non-operated Optc -/- cartilage, expression of SLRPs lumican and epiphycan was up-regulated at day 3 and in 10-week-olds (p ≤ 0.039), and fibromodulin down-regulated in 10-week-olds (p = 0.001). Immunohistochemistry of OA mice showed a similar pattern. In OA Optc -/- cartilage, markers of degradation and complement factors were all down-regulated (p ≤ 0.038). In OA Optc -/- cartilage, collagen fibers were thinner and better organized (p = 0.038) than in OA Optc +/+ cartilage. The protective effect of OPTC deficiency during OA results from an overexpression of lumican and epiphycan, known to bind and protect collagen fibers, and a decrease in fibromodulin, contributing to a reduction in the complement activation/inflammatory process. This work suggests that the evaluation of the composition of the different SLRPs in OA cartilage could be applied as a new tool for OA prognosis classification.

Efecto del condroitín sulfato en la sinovitis de pacientes con artrosis de rodilla / Effect of chondroitin sulphate on synovitis of knee osteoarthritic patients

Objetivo: Evaluar mediante ecografía el efecto del condroitín sulfato (CS) en la sinovitis de pacientes con artrosis (OA) de rodilla, y colaborar en el conocimiento de los mecanismos bioquímicos involucrados en la inflamación sinovial. Métodos: Estudio controlado, aleatorizado, ciego simple de 70 pacientes con OA de rodilla tratados durante 6 meses con CS o paracetamol (PCT). Los pacientes fueron visitados a tiempo basal, a las 6 semanas, y a los 3 y 6 meses para valorar el estado de su OA según los siguientes parámetros: sinovitis evaluada mediante ecografía (según definición de expertos OMERACT); dolor y función, mediante la escala visual analógica y el índice de Lequesne; y concentración de mediadores inflamatorios en suero y líquido sinovial, mediante ELISA. Resultados: El tratamiento con CS redujo en un 50% el número de individuos que presentaban sinovitis; sin embargo, se observó un incremento de un 123% en el grupo tratado con PCT. En los pacientes sin sinovitis inicial, se observó el establecimiento de esta en un 85,71 y 25% de los casos tratados con PCT y CS, respectivamente. Ambas terapias mejoraron la función articular, pero únicamente el tratamiento con CS produjo una mejora significativa del dolor al final del tratamiento. Se observó una asociación entre el tratamiento con CS y los cambios en la concentración de RANTES y UCN en el líquido sinovial. Conclusiones: El tratamiento con CS tiene un efecto mantenido beneficioso, previniendo la aparición de sinovitis o disminuyendo su presencia, así como reduciendo los síntomas de la artrosis. El PCT también mejora los síntomas clínicos, pero no tiene ningún efecto sobre la inflamación. Las variaciones observadas en la concentración de RANTES y UCN podrían estar relacionadas con el efecto antiinflamatorio asociado al tratamiento con CS (AU)

Objective: To evaluate by ultrasonography the effect of chondroitin sulfate (CS) on synovitis in patients with knee osteoarthritis (KOA). To collaborate in the understanding of the biochemical mechanisms involved in the synovial inflammation process. Methods: Randomized, single-blind, controlled trial involving 70 patients with primary KOA treated for 6 months with CS or acetaminophen (ACT). Evaluation of KOA status at baseline, 6 weeks, 3 and 6 months included: ultrasonography to assess synovitis (following the OMERACT expertise group definition), visual analogue scale and Lequesne index to measure pain and function, and ELISA to quantify inflammatory mediators in serum and synovial fluid. Results: Synovitis presence was reduced by 50% in the CS group while a 123% increase was observed in ACT group. Conversely, patients without initial synovitis and treated with ACT reached 85.71% synovitis onset, but only 25% in CS group. Both therapies improved articular function, but only CS resulted in significant pain improvement at the end of the treatment. Changes in RANTES and UCN synovial fluid concentration were associated with CS treatment. Conclusions: Treatment with CS had a sustained beneficial effect, preventing synovitis onset or reducing its presence as well as reducing KOA symptoms. ACT ameliorated clinical symptoms but had no effect on inflammation. The CS anti-inflammatory effect could be related to the observed changes in RANTES and UCN concentration (AU)

Effect of chondroitin sulphate on synovitis of knee osteoarthritic patients. / Efecto del condroitín sulfato en la sinovitis de pacientes con artrosis de rodilla.

OBJECTIVE: To evaluate by ultrasonography the effect of chondroitin sulfate (CS) on synovitis in patients with knee osteoarthritis (KOA). To collaborate in the understanding of the biochemical mechanisms involved in the synovial inflammation process. METHODS: Randomized, single-blind, controlled trial involving 70 patients with primary KOA treated for 6 months with CS or acetaminophen (ACT). Evaluation of KOA status at baseline, 6 weeks, 3 and 6 months included: ultrasonography to assess synovitis (following the OMERACT expertise group definition), visual analogue scale and Lequesne index to measure pain and function, and ELISA to quantify inflammatory mediators in serum and synovial fluid. RESULTS: Synovitis presence was reduced by 50% in the CS group while a 123% increase was observed in ACT group. Conversely, patients without initial synovitis and treated with ACT reached 85.71% synovitis onset, but only 25% in CS group. Both therapies improved articular function, but only CS resulted in significant pain improvement at the end of the treatment. Changes in RANTES and UCN synovial fluid concentration were associated with CS treatment. CONCLUSIONS: Treatment with CS had a sustained beneficial effect, preventing synovitis onset or reducing its presence as well as reducing KOA symptoms. ACT ameliorated clinical symptoms but had no effect on inflammation. The CS anti-inflammatory effect could be related to the observed changes in RANTES and UCN concentration.

Discrepancies in composition and biological effects of different formulations of chondroitin sulfate.

Osteoarthritis is a common, progressive joint disease, and treatments generally aim for symptomatic improvement. However, SYmptomatic Slow-Acting Drugs in Osteoarthritis (SYSADOAs) not only reduce joint pain, but slow structural disease progression. One such agent is chondroitin sulfate-a complex, heterogeneous polysaccharide. It is extracted from various animal cartilages, thus has a wide range of molecular weights and different amounts and patterns of sulfation. Chondroitin sulfate has an excellent safety profile, and although various meta-analyses have concluded that it has a beneficial effect on symptoms and structure, others have concluded little or no benefit. This may be due, at least partly, to variations in the quality of the chondroitin sulfate used for a particular study. Chondroitin sulfate is available as pharmaceutical- and nutraceutical-grade products, and the latter have great variations in preparation, composition, purity and effects. Moreover, some products contain a negligible amount of chondroitin sulfate and among samples with reasonable amounts, in vitro testing showed widely varying effects. Of importance, although some showed anti-inflammatory effects, others demonstrated weak effects, and some instances were even pro-inflammatory. This could be related to contaminants, which depend on the origin, production and purification process. It is therefore vitally important that only pharmaceutical-grade chondroitin sulfate be used for treating osteoarthritis patients.

Targeting of key pathogenic factors from gram-positive bacteria by the soluble ectodomain of the scavenger-like lymphocyte receptor CD6.

Gram-positive bacteria cause a broad spectrum of infection-related diseases in both immunocompetent and immunocompromised hosts, ranging from localized infections to severe systemic conditions such as septic and toxic shock syndromes. This situation has been aggravated by the recent emergence of multidrug-resistant strains, thus stressing the need for alternative therapeutic approaches. One such possibility would be modulating the host's immune response. Herein, the potential use of a soluble form of the scavenger-like human lymphocyte receptor CD6 (shCD6) belonging to an ancient family of innate immune receptors has been evaluated. shCD6 can bind to a broad spectrum of gram-positive bacteria thanks to the recognition of highly conserved cell wall components (lipoteichoic acid [LTA] and peptidoglycan [PGN]), which are essential for their viability and pathogenicity and are not amenable to antibiotic resistance. shCD6 has in vitro inhibitory effects on both bacterial growth and Toll-like receptor-mediated inflammatory response induced by LTA plus PGN. In vivo infusion of shCD6 improves survival on mouse models of septic shock by Staphylococcus aureus (either multidrug-resistant or -sensitive) or their endotoxins (LTA + PGN) or exotoxins (TSST-1). These results support the use of shCD6 and/or other scavenger-like immune receptors in the treatment of severe gram-positive-induced infectious conditions.

Characterization of opticin digestion by proteases involved in osteoarthritis development.

OBJECTIVE: Opticin is a class III member of the small leucine-rich repeat proteoglycan (SLRP) family, produced in articular joint tissues. In normal and osteoarthritic (OA) cartilage, opticin is degraded. This study aimed to assess whether human cartilage opticin is degraded by the main proteases involved in OA pathophysiology, and to determine the protease cleavage sites of this SLRP. METHODS: We analyzed the proteolytic activity of matrix metalloproteinases (MMPs)-1, -2, -3, -7, -8 and -9, and ADAMTS-4 and -5 on proteoglycan extracts from normal and moderately fibrillated OA human cartilage, and on recombinant human opticin. Opticin degradation was analyzed by Western blotting and cleavage sites were determined by sequence analysis. RESULTS: All eight proteases digested opticin from proteoglycan extracts from both normal and OA samples, as well as recombinant human opticin, MMP-2 and MMP-7 are the proteases that degrade recombinant human opticin most efficiently. The opticin cleavage site determined for these MMPs was between the glycosylation and leucine-rich repeat domains. MMP-7 had two additional digestion sites near the N-terminal end of opticin. CONCLUSION: Opticin is a substrate for several MMPs and aggrecanases involved during OA cartilage degradation, and seems to be a preferential substrate for MMP-7. The role of opticin in cartilage degeneration could be related to decreased levels of intact opticin, followed by its proteolytic degradation, which in turn may stimulate some of the modifications observed in the OA cartilage, such as neovascularisation and changes in the extracellular matrix.

Ser129D mutant alpha-synuclein induces earlier motor dysfunction while S129A results in distinctive pathology in a rat model of Parkinson's disease.

Alpha-synuclein phosphorylated at serine 129 (S129) is highly elevated in Parkinson's disease patients where it mainly accumulates in the Lewy bodies. Several groups have studied the role of phosphorylation at the S129 in α-synuclein in a rat model for Parkinson's disease using recombinant adeno-associated viral (rAAV) vectors. The results obtained are inconsistent and accordingly the role of S129 phosphorylation in α-synuclein toxicity remains unclear. This prompted us to re-examine the neuropathological and behavioral effects of the S129 modified α-synuclein species in vivo. For this purpose, we used two mutated forms of human α-synuclein in which the S129 was replaced either with an alanine (S129A), to block phosphorylation, or with an aspartate (S129D), to mimic phosphorylation, and compared them with the wild type α-synuclein. This approach was similar in design to previous studies, however our investigation of dopaminergic degeneration also included performing a detailed study of the α-synuclein induced pathology in the striatum and the analysis of motor deficits. Our results showed that overexpressing S129D or wild type α-synuclein resulted in an accelerated dopaminergic fiber loss as compared with S129A α-synuclein. Furthermore, the motor deficit seen in the group treated with the mutant S129D α-synuclein appeared earlier than the other two forms of α-synuclein. Conversely, S129A α-synuclein showed significantly larger pathological α-synuclein-positive inclusions, and slower dopaminergic fiber loss, when compared to the other two forms of α-synuclein, suggesting a neuroprotective effect of the mutation. When examined at long-term, all three α-synuclein forms resulted in pathological accumulations of α-synuclein in striatal fibers and dopaminergic cell death in the substantia nigra. Our data show that changes in the S129 residue of α-synuclein influence the rate of pathology and neurodegeneration, with an overall deleterious effect of exchanging S129 to a residue mimicking its phosphorylated state.