FIGURE 4.

Repression of CRABP-II by IBMX is mediated by PKA. a and b, preadipocytes were treated with IBMX (0.5 mm), forskolin (1 μm), or the PKA inhibitor H89 (1 μm) for 4 h or pretreated with H89 prior to treatment with IBMX or forskolin (fors). n/t, not treated. Levels of CRABP-II mRNA (a) and protein (b) were measured by Q-PCR and immunoblots, respectively. c, primary human preadipocytes isolated from three individual patients were treated with IBMX (0.5 mm, 4 h), and CRABP-II expression was analyzed by Q-PCR. d, preadipocytes were pretreated with cycloheximide (CHX) (10 μg/ml, 15 min) and then treated with IBMX (0.5 mm, 4 h). CRABP-II mRNA expression was analyzed by Q-PCR. Error bars indicate S.D.