Figure 2. Effect of TGF-β1 on IL-6 expression in human trabecular meshwork primary cultures. Three independent primary cultures of HTM cells were serum-starved for 16 h and then incubated in serum-free media with TGF-β1 (5 ng/ml). A: Levels of secreted IL-6 quantified by ELISA are shown. B: Levels of secreted IL-6 in cultures pre-treated with the TGFRI inhibitor (SB431542) before TGF-β1 treatment is shown in the chart. C: Differential IL-6 mRNA expression compared to the control at 3 h is shown. D: HTM cells were infected with AdIL6-SEAP (m.o.i=20 pfu/cell). At day 1 post-infection, cells were serum-starved for 24 h and then incubated in serum-free media with TGF-β1 (5 ng/ml). SEAP activity was assayed in the culture media at the indicated times. E: Differential IL-6 mRNA expression of HTM cells that were exposed to TGF-β1 in the presence of actinomycin D (4 μg/ml) is shown. The asterisk indicates that p is less than 0.05, and a double asterisk denotes that p is equal to 0.001. Statistical significance between groups was assessed by the paired Student's t-test (n=3).