Figure 6. BPR44 and BRP44L are involved in pyruvate transport.

(A) UK5099 structure and effect of adding either 25 µM MSDC-0160 (lane 2) or UK5099 (lane 3) on crosslinking of BRP44 (Mpc2). Lane 1 is the DMSO control. (B) Incubation of mouse BAT cells with UK5099 effectively limits carbon flow from U-¹³C glucose into acetyl CoA (red line) while MSDC-0602 has a biphasic dose response. The non TZD insulin sensitizer MRL-24 also modulated flow of carbon into acetyl CoA under these conditions. Data are the ratio of Acetyl CoA (¹³C/¹²C) derived from U-¹³C glucose following a 2 hour pre-incubation and a 15 minute flux at 37C (n = 3; mean and SE; representative of 3 experiments) as described in the Methods. (C) A separate experiment similar to that shown in B with other TZDs. (D) BAT progenitor cells were incubated with the indicated concentrations of UK5099 with (+) or without (−) 3 µM MSDC-0160 for 5 days. Cells were lysed and Western blots were conducted for UCP1 as in Figure 1B.