(A–B) Binding of FGFR2b and FGFR1b (A) or FGF10 (B) to immobilized GAGS. FGFR2b, but not FGF10, specifically binds to immobilized 3st3-HS. ELISA assays were performed in triplicate and repeated at least three times. Error bars: SEM.
(C) 3-O-HS increases the amount of FGF10 immunoprecipitated with FGFR2b. The intensity of the protein bands was normalized to FGFR2b and shown as a fold change in ratio of FGF10/FGFR2b. The graphs are 3 experiments combined and the blots from a representative experiment.
(D) BaF3 cells expressing FGFR2b or FGFR1b were incubated with 25nM GAGS (CSA, heparin, HS, 3st1-HS, or 3st3-HS) and 50nM FGF10 or 5nM FGF1. After 40 hr, the relative cell proliferation (A490) was determined. Data were normalized to FGFR2b-BaF3 cells treated with FGF10 or FGF1 and heparin.
Error bars: SEM. ANOVA; * p < 0.05, ** p < 0.01 and *** p < 0.001.
See also Figure S2.