Fig. 6.

Effect of ErbB4 signaling on glucose uptake. A: GLUT4 immunofluorescence in 3T3-L1 adipocytes treated for 15 min with insulin or neuroregulin 4 (NRG4) compared with vehicle-only controls (CTR). Secondary antibody (2nd Ab) only was used as negative control for immunofluorescent staining. Scale bars = 100 µm. B: glucose uptake of 3T3-L1 cells treated with NGR4, insulin, or NGR4 + insulin for 30 min. NRG4 treatment significantly stimulated glucose uptake by 3T3-L1 adipocytes, although not as potently as insulin. NRG4 did not show an additive effect on insulin-stimulated glucose uptake. RLU, relative light units; NS, not significant. Values are means ± SE. *P < 0.05. C: glucose uptake of isolated adipocytes from ErbB4 deletion or wild-type mice treated with NRG4 or insulin. Values are means ± SE. n = 5. *P < 0.01 vs. wild-type.