Fig. 2

Effects of exchange protein activated by cAMP (Epac) on the activation of the Janus kinase–signal transducers and activators of transcription (Jak-STAT) pathway in response to IL-6. a, b Pretreatment of neonatal rat cardiac myocytes with 8-(4-chlorophenylthio)-2′-O-Me-cAMP-AM (8-CPT-AM; 10 μmol/L) for 5 h significantly reduced both IL-6-mediated phosphorylation of STAT3 at Tyr705 by 57 ± 11.5% (a) (n = 5–6, **significantly different at p < 0.01, Student’s t test) and IL-6-mediated phosphorylation of STAT1 at Tyr701 by 65 ± 6.8% (b) (n = 6–8, ****significantly different at p < 0.0001, Student’s t test). c Pretreatment of neonatal rat cardiac myocytes with Epac1 selective inhibitor CE3F4 for 30 min significantly enhanced IL-6-mediated phosphorylation of STAT3 at Tyr705 by 35 ± 13.0% (n = 6, *significantly different at p < 0.05, one-way ANOVA). Data are presented as the mean ± SEM