| Obj ective:To explore the feasibility of the establishment of temporomandibular joint osteoarthritis model by removing part of posterior lateral joint disc in rabbits;To analysis the rebuilding situation and variation tendency of subchondral bone by Micor-CT;To detect the Expression of Sox9,MMP-13 and VEGF in condylar cartilage and subchondral bone at different stages of temporomandibular joint osteoarthritis by immunohistochemical staining and explore the mechanism of their effects on subchondral bone remodeling and osteoarthritis.Methods:Twenty-four healthy 5-month-old New Zealand white rabbits were randomly divided into two groups:experimental group(n=12)and sham-operated group(n=12).In the experimental group,A full-thickness perforation of diameter 2.5mm was made on the posterolateral side of the articular disc.In the sham operation group,the tissue was sutured only after the incision of the joint capsule.At 4,8,12,16 weeks after operation,three animals in each group were killed to make temporomandibular joint specimens.The ratio of bone volume to tissue volume(BV/TV),the ratio of bone surface area to bone volume(BS/BV),trabecular thickness(Tb.Th),trabecular separation(Tb.Sp)and trabecular number(Tb.N)of the subchondral bone at the top of the condyle were scanned and calculated by Micro-CT.HE staining and immunohistochemical staining of Sox9,MMP-13,VEGF antibody were made.Semi-quantitative analysis of the expression of Sox9,MMP-13,VEGF in subchondral bone was done by software of Image-ProPlus.Statistical analysis of data results was performed by software of SPSS.Results:Results of Micro-CT:In the experimental group,the subchondral bone was not continuous and the bone mineral density was significantly decreased.The levels of BV/TV,Tb.Th and Tb.N in the experimental group were significantly lower than those in the sham operation group(P<0 05),with a trend of decreasing first and then rising.The levels of BS/BV and Tb.Sp in the experimental group were significantly higher than those in the sham operation group(P<0 05),with a trend of rising first and then descending.Results of histopathological staining:In the sham operation group,there was only mild inflammatory reaction at the 4th week.In the experimental group,the condylar surface was irregular with fissure,the cartilage layers were thickened obviously,and the chondrocytes eroded into the subchondral bone.The thickened condylar cartilage began to thin at the 8th week,and at the 16th week the skeleton appeared on the articular surface of the condylar process.Results of immunohistochemical staining:The expression of Sox9,MMP-13 and VEGF in the experimental group was significantly higher than those in the sham operation group at the same time point.Sox9,MMP-13 was expressed in both condylar cartilage and subchondral bone,and VEGF was weakly expressed in cartilage layer and subchondral bone.The expression of Sox9,MMP-13 and VEGF in the experimental group rose increasingly.The expression of Sox9 in experimental group increased most rapidly from 8th week to 12th week,and the expression of MMP-13 and VEGF in experimental group increased most rapidly from 1 2th week to 16th week.Conclusion:1.The model of rabbit temporomandibular joint osteoarthritis was successfully established by posterolateral joint disc perforation.2.It is confirmed that the active remodeling of subchondral bone was an important feature of temporomandibular joint osteoarthritis by analyzing and detecting BV/TV,BS/BV,Tb.Th,Tb.Sp and Tb.N of subcartilage bone.3.The expression and localization of Sox9,MMP-13 and VEGF in condyle have complex reaction mechanism,which may be of great significance to the bone remodeling of subcartilage bone and the development of osteoarthritis. |
PDF Full Text Request