Figure 2.

The transcriptional response of synovium to surgical induction of osteoarthritis. (A) 14,173 transcripts were expressed >1 RPKM in at least one of the 7 groups defined by ACL status, time and treatment. Log2 fold-changes compared to INTACT controls are depicted as heatmap. (B) Number of differentially expressed genes by time-point and treatment. Most differentially expressed genes were detected in the comparison of post-surgery groups with intact controls, rather than between the surgical groups (each group with n=6). (C) Number of differentially expressed genes by time-point (with surgical groups pooled, 1W and 4W with n=18 each, Intact with n=6). Vast changes in gene expression were observed between 1 or 4 week post-surgery with controls and between 1 and 4 weeks post-surgery. (D) 1683 transcripts were concordantly differentially expressed in the comparison of 1W and 4W with intact controls (One disconcordant between 1 and 4 weeks). Those transcripts enriched 11 pathways (process network ontology), including terms related to cell cycle, cytoskeleton, cell adhesion, inflammation, proteolysis, development, and signal transduction.