Transfection with a Cx43 expression construct increased the expression of IL1B , IL6 and PTGS2 mRNA in HIG82 synovial fibroblasts in vitro. By quantitative real time RT-PCR, transient transfection of HIG82 rabbit synovial fibroblasts with increasing concentrations of a rat Cx43 expressing plasmid (pSFFV-Cx43) dose dependently increased the gene expression of IL1B, IL6 and PTGS2. N = 3. Total DNA was kept constant in all wells by the inclusion of the appropriate amount of an empty vector (pSFFV-neo). Data are shown as means ± standard deviations. Asterisks indicate p-value < 0.05 relative to the empty vector (0 μg) control.