Fig. 2. USP14 expression is induced by PDGF-BB in a dose- and time dependent manner. The HASMCs were incubated with different concentrations of PDGF-BB for different time periods, and then the expression levels of USP14 were measured using qRT-PCR and western blot analysis. (A and B) Expressions of USP14 in HASMCs after incubation with increasing concentrations of PDGF-BB (0, 5, 10, 20, 40, 80 ng ml⁻¹) for 24 h. (C and D) Expressions of USP14 in HASMCs after incubation with 40 ng ml⁻¹ of PDGF-BB for a series of time periods (0, 6, 12, 24, 36, 48 h). *p < 0.05.