safranine-t and Osteoarthritis--Knee

To investigate the effect of vascular endothelial growth factor (VEGF) stimulation and the effect of blocking VEGF with its antagonist, soluble Flt-1 (sFlt-1), on chondrogenesis, using muscle-derived stem cells (MDSCs) isolated from mouse skeletal muscle.. The direct effect of VEGF on the in vitro chondrogenic ability of mouse MDSCs was tested using a pellet culture system, followed by real-time quantitative polymerase chain reaction (PCR) and histologic analyses. Next, the effect of VEGF on chondrogenesis within the synovial joint was tested, using genetically engineered MDSCs implanted into rat osteochondral defects. In this model, MDSCs transduced with a retroviral vector to express bone morphogenetic protein 4 (BMP-4) were coimplanted with MDSCs transduced to express either VEGF or sFlt-1 (a VEGF antagonist) to provide a gain- and loss-of-function experimental design. Histologic scoring was used to compare cartilage formation among the treatment groups.. Hyaline-like cartilage matrix production was observed in both VEGF-treated and VEGF-blocked (sFlt-1-treated) pellet cultures, but quantitative PCR revealed that sFlt-1 treatment improved the expression of chondrogenic genes in MDSCs that were stimulated to undergo chondrogenic differentiation with BMP-4 and transforming growth factor beta3 (TGFbeta3). In vivo testing of articular cartilage repair showed that VEGF-transduced MDSCs caused an arthritic change in the knee joint, and sFlt-1 improved the MDSC-mediated repair of articular cartilage, compared with BMP-4 alone.. Soluble Flt-1 gene therapy improved the BMP-4- and TGFbeta3-induced chondrogenic gene expression of MDSCs in vitro and improved the persistence of articular cartilage repair by preventing vascularization and bone invasion into the repaired articular cartilage.

Topics: Animals; Bone Morphogenetic Protein 4; Cartilage, Articular; Cell Differentiation; Cells, Cultured; Chondrogenesis; Genetic Therapy; Hyaline Cartilage; Indicators and Reagents; Male; Mice; Mice, Inbred C57BL; Muscle, Skeletal; Osteoarthritis, Knee; Phenazines; Rats; Rats, Nude; Solubility; Stem Cell Transplantation; Stem Cells; Transduction, Genetic; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1

In this study, we have examined the correlation between the histological and histochemical changes of articular cartilage and bone parameters of the underlying subchondral bone. The aim was to elucidate patterns of bone parameter changes within different depths of subchondral bone in the joints with macroscopically normal cartilage and in joints with osteoarthritis (OA). Ten tibial plateaus were taken from patients during total knee replacement surgery due to severe OA. They were compared with 10 sets of tibial condyles obtained from autopsy subjects with no history of bone or joint disease. The cylindrical cartilage-bone samples were taken out from the anterior, posterior, external, and internal areas of the condyles for cartilage assessment (Mankin score) and subchondral bone histomorphometry. Four histomorphometric parameters were measured: bone volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.S). Our study showed that subchondral bone from the OA group had significantly higher bone volume (54.1 +/- 10.6%) than control group (37.8 +/- 8.1%) (P < 0.01). In addition, trabecular parameters from the OA subchondral bone showed a smaller number of sparsely distributed and thicker trabecules than in control group (P < 0.05). Medial and lateral condyle from the control group did not differ significantly, while medial condyle from OA group showed a high increase of bone volume (62.8 +/- 13.3) and consecutively different trabecular parameters when compared with the lateral condyle from the same group. Also, it was shown that there are regional differences (anterior, posterior, internal, and external) in bone parameters between both condyles within both, control and OA groups. Comparison of bone parameters from three different stage of articular cartilage degeneration (Mankin score) showed that higher degree of cartilage degeneration is followed by significant changes in subchondral bone architecture. Furthermore, we have found that progression of cartilage degeneration leads to changes in bone parameters which affected deeper levels of subchondral bone. According to these results, it can be suggested that changes in histomorphometric parameters of subchondral bone are secondary to cartilage damage and proceed deeper into subchondral bone with increasing cartilage degeneration.

Topics: Adult; Cartilage, Articular; Female; Humans; Indicators and Reagents; Knee Joint; Male; Middle Aged; Osteoarthritis, Knee; Phenazines; Tibia

To determine the validity of the histological-histochemical grading system (HHGS) for osteoarthritic (OA) articular cartilage.. Human articular cartilage was obtained from macroscopically normal (n = 13) and OA (n = 21) knee joints. Sections of central and peripheral regions of normal samples were produced. Sections of regions containing severe, moderate, and mild OA changes were produced from each OA sample. A total of 89 sections were graded by means of the HHGS (0-14) twice by three observers.. Average scores for regions designated severe (8.64) and moderate (5.83) OA were less than the expected (10-14 and 6-9, respectively) according to the HHGS, whereas average scores for the region designated mild (5.29) OA and central and peripheral regions (2.19) of normal cartilage were higher than expected (2-5 and 0-1, respectively). The HHGS was capable of differentiating between articular cartilage from macroscopically normal and OA joints and between the region designated severe OA and other regions. However, the HHGS did not adequately differentiate between regions designated mild and moderate OA. Values for sensitivity, specificity, and efficiency for all regions varied considerably.. The HHGS is valid for normal and severe OA cartilage, but does not permit distinction between mild and moderate OA changes in articular cartilage.

Topics: Adolescent; Adult; Aged; Cartilage, Articular; Coloring Agents; Female; Histocytochemistry; Humans; Male; Middle Aged; Osteoarthritis, Knee; Phenazines; Reproducibility of Results

To evaluate, histomorphometrically and biochemically, different protective effects of clinically used hyaluronans (HA).. An experimental osteoarthritis (OA) model was applied to 132 mature NZW rabbits by resecting the unilateral anterior cruciate ligament (ACL). The other knee, where ACL remained intact, served as the control. We used native HA with different molecular weights, HA-50 (MW 5-7.3 x 10(5)), HA-80 (MW 8 x 10(5)), HA-360 (MW 3.6 x 10(6)), and crosslinked HA (HA-CL). HA were injected into the joint once a week for 5 weeks (HA-50, HA-80, HA-360) or 3 weeks (HA-CL) beginning 4 weeks after ACL transection. Histomorphometric and biochemical assessment was performed 9 weeks post-transection for both the HA treated and nontreated groups.. In gross morphological observation, cartilage degeneration was suppressed in HA treated groups, and this effect was superior in the groups receiving either HA-80 or HA-CL. Histomorphometric and biochemical analyses of the articular cartilage revealed similar results: the HA-80 and HA-CL groups showed no significant differences between the ACL transection and the control knees by histomorphometric variables, while the nontreated groups revealed significant degeneration. These evaluations were done in unblinded fashion. Biochemical analyses, including DNA synthesis in the synovium, also showed that articular cartilage and synovium in the HA-80 and HA-CL groups did not present significant changes compared to controls.. In quantitative evaluation of this short term study using the OA model, native HA-80 and HA-CL presented a superior cartilage protective effect compared to the other native HA.

Topics: Animals; Cartilage, Articular; Coloring Agents; Hyaluronic Acid; Osteoarthritis, Knee; Phenazines; Rabbits; Synovial Membrane