The articular cartilage preservative effects of genistein in an experimental model of knees osteoarthritis.

The study aimed to investigate the preservative effects of genistein on articular cartilage in an experimental model of knee osteoarthritis in rats. Thirty male Wistar rats were assigned to 3 equal groups: sham group, osteoarthritis control group (OAG), and genistein-treated osteoarthritis group (GTG). Intra-articular injections of monosodium iodoacetate were used for osteoarthritis induction. After 2 weeks of rest for the induction of the inflammatory process, genistein (30 mg/kg/day) vs. saline gavage was administered for 8 weeks. The expression of matrix metalloproteinase (MMP)-8 and MMP-13, Sox5/Sox6, Indian hedgehog (IHH), and Col2 were evaluated in medial femoral condyle sections by immunohistochemical staining. The number of chondrocytes and cartilage thicknesses were also measured and compared among the groups. No significant change in cartilage thickness was observed in GTG compared with OAG (p = 0.188). Chondrocyte count was significantly higher in the articular cartilage of GTG compared with OAG (p = 0.006). Induction of osteoarthritis significantly increased the expression of MMP-8, MMP-13, and IHH, but decreased Col2, Sox5, and Sox6 expression (p < 0.001); these were partially prevented in the GTG. Our findings support the effectiveness of genistein treatment in the prevention of articular cartilage damage in the experimental model of knee osteoarthritis. The proposed mechanism of action is through the suppression of the MMP, IHH, and Col2 pathways, besides the induction of Sox5 and Sox6 expression. Novelty: Genistein prevents articular cartilage damage in the experimental model of knee osteoarthritis. The osteoprotective effect is manifested by the modulation of expression of MMP, Sox, IHH, and Col2 proteins.

Combinatorial gene therapy induces regression of hepatic encephalopathy.

Capillarization of the sinusoid impedes the clearance of neurotoxic substances in liver fibrosis. These events may result in hepatic encephalopathy. Neurological and hepatic features of rats after bile duct ligation (BDL) supplemented with Manganese (BDL+Mn(2+)) were examined. The 4-week-old BDL rats had elevated levels of ammonia and were concomitantly fed with 1 mg ml(-1) of MnCl(2) in drinking water (BDL/Mn(+2)). Five out of fifteen rats were killed and the serum, liver and brain tissue (striatum and substantia nigra) were recovered. Of the remaining BDL/Mn(+2)-cirrhotic animals (n=10), five were injected with a combination of Adenovirus-human plasminogen activator (Ad-huPA) and Adenovirus-matrix metalloproteinase-8 (Ad-MMP-8) (3 × 10(11)+1.5 × 10(11) vector particles per kg), and five with 4.5 × 10(11) vector particles per kg of Adenovirus-ß-galactosidase (Ad-ß-Gal). This treatment was carried on for 10 days. The BDL/Mn(+2) rats displayed tremor, rigidity and gait abnormalities, which improved notably with combinatorial gene therapy, as well as motor coordination. Liver fibrosis was evidently less after treatment with Ad-huPA+Ad-MMP-8 (25%). In the brain (striatum), Ad-huPA+Ad-MMP-8 treatment rendered higher concentrations of dopamine compared with Ad-ß-Gal-treated encephalopathic rats (210 and 162 ng g(-1) of tissue, respectively). The BDL/Mn(+2) animals and controls treated with Ad-ß-Gal showed abnormal morphology in astrocytes (gliosis) in striatum and substantia nigra, in which expressions of green fibrillar acidic protein and tyrosine hydroxylase were altered. These abnormalities decreased with Ad-huPA+Ad-MMP-8 treatment. Importantly, the latter animals showed an increment in sprouting of nervous fibers in substantia nigra. Combinatorial gene therapy improves neuroanatomical and neurochemical characteristics similar to human hepatic encephalopathy.

Matrix metalloproteinase 10 promotion of collagenolysis via procollagenase activation: implications for cartilage degradation in arthritis.

OBJECTIVE: We have previously reported the up-regulation of matrix metalloproteinase 10 (MMP-10) following treatment with the procatabolic stimulus of interleukin-1 (IL-1) and oncostatin M (OSM) in chondrocytes. Although MMP-10 is closely related to MMP-3, little is known about the role of MMP-10 in cartilage catabolism. The purpose of this study was to determine whether MMP-10 is expressed in connective tissue cells and to assess how it may contribute to cartilage collagenolysis. METHODS: MMP gene expression was assessed by real-time polymerase chain reaction using RNA from human articular chondrocytes and synovial fibroblasts stimulated with IL-1 plus OSM or tumor necrosis factor alpha (TNFalpha) plus OSM. Synovial fluid levels of MMP-10 were determined by specific immunoassay. Recombinant procollagenases were used in activation studies. Immunohistochemistry assessed MMP-10 expression in diseased joint tissues. RESULTS: MMP-10 expression was confirmed in both chondrocytes and synovial fibroblasts following stimulation with either IL-1 plus OSM or TNFalpha plus OSM, and MMP-10 was detected in synovial fluid samples from patients with various arthropathies. Exogenous MMP-10 significantly enhanced collagenolysis from IL-1 plus OSM-stimulated cartilage, and MMP-10 activated proMMP-1, proMMP-8, and proMMP-13. Immunohistochemistry revealed the presence of MMP-10 in the synovium and cartilage of an IL-1 plus OSM-induced model of arthritis as well as in samples of diseased human tissues. CONCLUSION: We confirm that both synovial fibroblasts and articular chondrocytes express MMP-10 following treatment with procatabolic stimuli. Furthermore, the detectable levels of synovial fluid MMP-10 and the histologic detection of this proteinase in diseased joint tissues strongly implicate MMP-10 in the cartilage degradome during arthritis. The ability of MMP-10 to superactivate procollagenases that are relevant to cartilage degradation suggests that this activation represents an important mechanism by which this MMP contributes to tissue destruction in arthritis.