Figure 4. PDGF-induced cell proliferation involves JAK2-STAT3 pathway. Human corneal fibroblasts were exposed to PDGF in the presence or absence of JAK2-STAT3 inhibitor, AG-490, for 1 h, 8 h, or 48 h, and cell proliferation was quantified using the MTT assay. PDGF induced cell proliferation significantly in HSF, and AG-490 showed significant suppression of PDGF-induced cell proliferation. Data are shown as mean ±SD of absorbance at 570 nm. The asterisk indicates a p<0.001 versus control, the double asterisk indicates a p<0.01 versus PDGF, and the triple asterisk indicates a p<0.001 versus PDGF.