Figure 4. Inflammatory cytokine mRNA expression in ocular surface epithelia of BTX-B injected and normal control mice. mRNA expression levels of TNF-α and IL-1β in BTX-B injected mice increased significantly at early time points, but normal and saline-injected control mice showed no significant difference. Total RNAs were isolated from cornea and conjunctiva at different time points after BTX-B injection and uninjected contra-lateral eyes were used as controls. Each time point contained five samples. Results are represented as the ratio of cytokine copy number and Cyclophilin A. Error bar: standard deviation of each group. Black bar: BTX-B injected groups, empty bar: Saline-injected groups. The asterisk indicates significant differences between the two groups (p<0.01). The rest without asterisks denote no significant differences between the two groups (p>0.05).