Fig. 9.

Exogenous addition of gangliosides GM3 and GT1b (but not GM1) to 3T3-L1 adipocytes enhances insulin-mediated Akt phosphorylation. Adipocyte-differentiated 3T3-L1 cells were cultured for 24 h in medium containing 50 μM BSA (control) or 50 μM ganglioside–BSA complex as indicated. After washing, cells were treated for 5 min with 10 nM insulin, lysed, and the relative amount of phosphorylated Akt compared to total Akt was determined by immunoblotting. Data are expressed as the ratio of arbitrary density units. Cells treated with GM3 or GT1b (but not GM1) had a higher relative phospho-Akt than WT (P < 0.001, two-way ANOVA). *P < 0.001, Tukey post-hoc analyses. Data are expressed as mean ± SE n = 3 replicate cultures per group. BSA, bovine serum albumin.