Figure 6.

Effects of SFN treatment on 3T3-L1 adipocytes during differentiation. (A) Table displays eight treatment conditions (SFN ± starting and ending on different days). Growth at day 8 is shown in photographs at two magnifications. Treatment for 2, 4, 6 or 8 days inhibits adipogenesis. Treatments starting at day 2 or later have less effect. (B) PparG2 expression by real-time PCR increases rapidly after day 3 under standard differentiation conditions indicating commitment to terminal adipocyte state. Continuous SFN treatment prevents differentiation. (C) Rxra expression is higher under SFN treatment conditions. (D) Expression of Pgc1B, the PPAR coactivator (homolog of human PPARGC1B), is similar to Pparg2 both untreated and treated. (E) Gata3, a negative regulator of adipogenesis, dips initially, then increases dramatically by Day 3 with SFN treatment. (F) Rxra expression was tested in 3T3-L1 adipocytes with shRNA knockdown of Nrf2 (Nrf2-Kd, green) and Keap1 (Keap1-Kd, red). Keap1 knockdown genetically activates Nrf2. The Rxra expression profile under Keap1 knockdown (red triangles) is very similar to that observed for SFN treatment (C, red squares). Nrf2 knockdown (green) delays the rise in Rxra expression. This is accompanied by impaired adipogenesis (32).