Expression data from mouse arthritis tarsal joints

Pathological bone changes differ considerably between inflammatory arthritic diseases, and most studies have focused on bone erosion. Collagen Induced Arthritis (CIA) is a model for Rheumatoid Arthritis, which, in addition to bone erosion, demonstrates bone formation at the time for clinical manifestations. The objective of this study was to use the CIA model to study bone remodelling by performing a gene expression profiling time-course study on the CIA model. Three tarsal joints were sampled per clinical phase from the following clinical phases: Duration of clinical arthritis 0-3 days, duration of clinical arthritis 1-2 weeks, duration of clinical arthritis 3-4 weeks and duration of clinical arthritis minimum 3 weeks and declining (Twelve joints in total). For the clinical phase “Decline” the joints had had a clinical score of 3 for minimum 3 weeks, after which the clinical score had declined minimum 1 score when the joint was sampled. For all other joints, the clinical score was 3 at the sampling time. The twelve joints were compared to three joints from non-induced control animals. The joints were processed and analysed separately (unpooled ). The joints were snap-frozen in liquid N2 and stored at -80˚C. RNA was extracted using the mirVanaTM miRNA isolation kit (Ambion, Denmark), amplified and labelled using the Pico amplification kit (Nugen, San Carlos, USA), according to the manufacturers´ instructions, followed by hybridisation to Mouse Gene 1.0ST microarrays (Affymetrix, Santa Clara, USA). The quality of the RNA was evaluated using RNA integrity numbers (RIN) and only samples with values of minimum 8.4 were chosen for further analysis.