Figure 4
Effect of MAP Kinase Inhibition on TER and Paracellular Flux in TNFα and IFNγ-treated MDCK cells. The effect of the MAP kinase inhibitors was investigated by TER assessment and [3H]-mannitol flux determination in the presence of TNFα and IFNγ. MDCK cells were placed into one of eight treatment groups for 24 hours; control, TNFα/IFNγ alone (30/60 ng/ml) or proinflammatory cytokine with U0126 (1 and 10 μM), SB202190 (1 and 10 μM), combined U0126 and SB202190 (1 μM each) or SB600125 (1 μM). TER was assessed using the EVOM system (Panel A) then flux was determined following incubation at 37°C for two hours with [3H]-mannitol in the apical chamber (Panel B). Recovery of tracer was measured in the basolateral chamber and expressed as fold change from the control group. Exposure to TNFα/IFNγ produces a significant two-fold elevation in paracellular flux; MAP kinase inhibitors protect barrier function to varying degrees. Error bars represent the mean ± SE of four independent experiments. ANOVA was performed, multiple comparisons between all treatments were determined with the Tukey-HSD post test. **Indicates statistically difference (P < 0.01) to the TNFα/IFNγ group.