Fig. 1
The proteolytic balance is impaired in mBSA/IL-1β-induced arthritis. a. Analytical agarose gel electrophoresis of RT-qPCR products for Spag11c and Spag11a mRNA in knee joints from control or arthritis mice. Hrpt1 was used as an endogenous control. Adult mouse epididymis cDNA was used as positive control for Spag11c and Spag11a mRNA amplification. b. RT-qPCR analysis of Spag11c relative expression in control and arthritis mouse knee joints. N = 6 mice per group. c-h. In situ hybridization with Spag11c or scrambled digoxigenin-labelled LNA probes in knee joint sections from control and arthritis mice. Hybridization signal was detected in chondrocytes within the hyaline cartilage from control and arthritis mice (c and e) and in cells from the synovial membrane (d and f). No staining was observed in negative control assays with scrambled digoxigenin-labelled LNA probe, neither in hyaline cartilage (g) nor in the synovial membrane (h). Right bottom insets represent magnifications of the respective square-demarked areas. The arrowheads indicate the normal synovial lining in control animals. The arrows evidence the presence of several mast cells in arthritis mice. Images are representative of five mice per group. i. RT-qPCR analysis of Mcpt-6 relative expression in control and arthritis mouse knee joints. N = 11–12 mice per group. j. Measurement of tryptase-like activity in the synovial fluid from knee joints of control and arthritis mice. N = 13–15 mice per group. Abbreviation: n.s. not significant