Fig 5. GLUT10 modulates intracellular ascorbic acid levels and regulates adipogenesis.

(A) 3T3-L1 preadipocytes were incubated with 75 μM ¹⁴C-labeled DHA for 30 min. Intracellular ¹⁴C DHA levels (left panel) and intracellular ascorbic acid (AA) levels (right panel) were determined. (B) 3T3-L1 preadipocytes were cultured in medium containing 75 μM AA, and intracellular (left panel), cytoplasmic and nuclear AA levels (right panel) were determined. (C-F) shGlut10 and shLuc 3T3-L1 cells were cultured in normal medium (4 μM AA from serum, mock) or supplemented with 75 μM AA for 2 days. Adipogenic differentiation was induced for 6 days in C and D. Adipogenic differentiation was induced for the indicated number of days in E and F. (C) Representative images of oil red O staining and (D) quantification of the oil red O staining. (E and F) Relative mRNA expression of Cebpa and Pparg was determined by RT-PCR. n = 3 independent experiments per group. Data are shown as the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001.