Figure 1:

PCB 126 or indoxyl sulfate (IS) treatment of preadipocytes blocks the beiging response in subsequently differentiated adipocytes. A. White adipocytes (WAT) are activated by norepinephrine (NE) to upregulate the uncoupling protein (UCP1) gene in a process referred to as beiging. B. Preadipocytes were treated with vehicle (DMSO) or PCB126 at concentrations of 2 or 10 μM for 4 days after the PCB126 was removed followed by differentiation for 10 days. Differentiated adipocytes were treated with norepinephrine at 10 μM for 6 hours in media without serum after which the cells were collected for RNA and assessed for UCP1 transcript levels as described in the Materials and Methods. Levels were normalized to GAPDH. Shown values are fold-changes over non-stimulated (no NE) controls. C. Preadipocytes were treated with vehicle (DMSO) or IS at concentrations of 10 or 50 μM for 4 days after which the IS was removed and cells were differentiated. Fold changes in NE-induced UCP1 induction were assessed as in B. For both B and C, values represent three replicates. Statistical analysis was performed using the GraphPad Prism program and one-way ANOVA with Dunnett’s multiple comparison test (*** p<0.001; **** p<0.0001).