Figure 3

Immunostaining of pSTAT3 in C6-ObRb cells. (A) C6-ObRb cells were stimulated for 1–2 min with leptin (100 nM) or CCK-8s (10 nM) 30 min prior to fixation. pSTAT3 (red) images were merged with DAPI nuclear staining (blue) on the right. Note that leptin stimulation increased nuclear pSTAT3 whereas CCK-8s rather increased cytosolic pSTAT3. Co-stimulation with leptin and CCK-8s resulted in nuclear pSTAT3 expression whereas the level was not different from un-stimulated controls. (B) Nuclear fluorescent intensities of pSTAT3 were compared. AG490 (1 µM) or LY294002 (50 µM) blocked leptin-induced nuclear pSTAT3 elevation. **p < 0.01 by Duncan’s multiple range test following one-way ANOVA.