Fig. 4.

Impact of Epac1/2 knockdown on Col1 and Col3 expression. a Epac activity was analyzed after incubation with CGS21680 1 μM for 15 min. Immunoprecipitation with Ral GSD-RBD was performed followed by immunoblot with anti-Rap1, and Coomassie stain identified Ral GSD-RBD at the predicted molecular weight of 37 kDa. b siRNAs for Epac1, Epac2, and double knockdown Epac1 + 2 selectively reduce the protein expression when compared to control siRNA. c Impact of Epac1, Epac2 silencing, or double knockdown Epac1 + 2 on basal and CGS21680-increased Col1 and Col3 expression. Statistics was performed by the two-way ANOVA: Epac2 siRNA ***P < 0.001 and Epac1 + 2 siRNA ^## P < 0.01 vs. control siRNA. Black triangle represents the increasing concentrations of CGS21680 0.1–1–10 μM, and data represent means ± SEM of three or more independent experiments