FIGURE 2.
Down-regulation of HYBID-mediated HA depolymerization by TGF-β1, bFGF, EGF, and PDGF-BB. A, HA depolymerization by Detroit 551 cells treated with growth factors. Cells treated without (Control; open circle) or with 1 (gray triangle) or 10 ng/ml (closed circle) TGF-β1, bFGF, EGF, or PDGF-BB were cultured with [3H]HA for 48 h, and HA fragments in the culture media were examined by size-exclusion chromatography. B and C, the expression levels of HYBID mRNA (B) and protein (C) in cells treated without (Control) or with 1 or 10 ng/ml TGF-β1, bFGF, EGF, or PDGF-BB. The mRNA levels at 8 and 24 h and the protein expression at 24 h after the treatment were measured by quantitative real-time PCR and immunoblotting, respectively. Values are expressed as the mean ± S.D. (n = 3) and shown as -fold increases in mRNA expression relative to 8 h control cells. Dunnett's test was used for statistical analysis. ***, p < 0.001.