Figure 1.

Effect of TNF-α on MMP-1 mRNA expression and protein synthesis in fibroblasts of normal cornea (n = 3) and keratoconus (n = 3). Cells were incubated for 12 h in the presence of various concentrations of TNF-α and stimulated with the absence or presence of 1 ng/mL TNF-α for the indicated times intervals. Total RNA and cell-culture supernatants were then collected. (a and d) Levels of MMP-1 mRNA measured by real-time PCR from total RNA. (b, e, and f) Representative Western blot for MMP-1 protein in cell-culture supernatants. (c and g) Quantitative analysis of MMP-1 protein levels by Image-Pro Plus. The results are presented as mean ± standard deviation of three independent experiments. KC: keratoconus, NC: normal cornea. Cells without TNF-α treatment were used as control. * P < 0.05, compared with their own control group; ^#P < 0.05, KC control group vs. NC control group