Matrix metalloproteinases (MMPs) are tissue-enzymes that play an integral role during the remodeling process, such as in inflammatory diseases. areas (morphometric analysis) stained with MMP-7 and MMP-9 antibodies were expressed as % positive, dark brown pixels of the analyzed fields. While, the levels (high/low) of staining intensity of positive areas (densitometric analysis) were expressed as densitometric count (pixel2) of positive, dark brown pixels of the analyzed fields. These parameters were calculated using software for image acquisition (AxioVision Release 4.8.2 – SP2 Software, Carl Zeiss Microscopy GmbH, Jena, Germany). Data were expressed as mean standard deviation (SD). Digital micrographs were taken and fitted as previously described. Statistical analysis Statistical analysis was performed using GraphPad Prism 7.0 (GraphPad Software, Inc., La Jolla, CA, USA). Data were tested for normality with the Kolmogorov-Smirnov test. All variables were normally distributed. Students em t- /em test was used for comparisons between two means. P-values less than 0.05 (P 0.05) and 0.001 (P 0.001) were considered statistically and very statistically significant, respectively. Results MMP-7 and MMP-9 expression was confirmed, following immunohistochemistry. Staining was localized in fibroblast-like type B cells expressing MMP-7 and MMP-9. All experimental samples were identified as positively stained. As shown in Physique 1, densitometric expression of MMP-7 and MMP-9 was significantly increased in ADDwoR when compared to the handles (P 0.001). Rabbit polyclonal to ANKRD50 Nevertheless, as proven in Body 2, there is no factor between MMP-7 (Body 2A) and MMP-9 (Physique 2B) immunostainings (P 0.05). ADDwoR fibroblasts staining intensity, localized in the inner layer of the synovial membrane, was statistically significant compared to the control tissue (Physique 2C) (P 0.001). Conversation MMPs have been shown to play an important role in AMG-925 ECM homeostasis and in joint disc remodelling. Our results showed a statistically significant difference in MMP-7 and MMP-9 immunoexpression was detected between the synovial tissues of ADDwoR and control samples. The expression of these MMPs is regulated by several factors including a variety of cytokines, which play an important role in TMJ ID pathogenesis. They have indeed been exhibited in SF of pathological TMJ, suggesting that their expression could be a potential biochemical marker for articular cartilage degradation.8,15,22 Physique 1. Open in a separate window Densitometric analysis. A bar chart representing a comparison of the percentage of MMP-7 and MMP-9 immunostained area AMG-925 in ADDwoR synovial tissues vs. synovial control tissues, expressed by positive percentage, dark brown pixels of the analyzed fields. Data are offered as meanSD. *P 0.001. Physique 2. Open in a separate windows MMP-7 (A) and MMP-9 (B) immunoexpression of fibroblasts in synovial tissue sample of ADDwoR patient, respectively; magnification 600 x; level bars: 30 m; *P 0.05. C) MMP- 7 immunoexpression in synovial tissue control sample; magnification 400 x; level bar: 60 m. MMP-7 and MMP-9 are expressed in arthritic joints and can degrade a number of matrix proteins in the joint.29 In osteoarthritis, synovial macrophages, synovial fibroblasts, and chondrocytes may induce the release of MMPs which destroy joint cartilage.11,30 In particular, human TMJ AMG-925 synovial cells have been reported to synthesize MMP-1, MMP-3, and MMP-9 em in vitro. /em 31,32 Transmission electron microscopy analysis showed two types of synovial lining cells, including the macrophages-like type A and fibroblast-like type B cells in the synovial lining layer of TMJ. In particular, a secretory function was attributed to fibroblast-like type B cells.29 These cells secrete type I and II collagens, fibronectin, and glycosaminoglycans into the synovial interstitium and fluids.29,33-35 Therefore, it is reasonable to think that this MMPs overexpression AMG-925 within the synovial fluid derives in the secretory activity of fibroblast-like type B cells that showed inside our study an overexpression of both MMP-7 and MMP-9. To conclude,.