Expression of GPR43 in Brown Adipogenesis Is Enhanced by Rosiglitazone and Controlled by PPARγ/RXR Heterodimerization

Figure 3

Rosiglitazone-mediated increase of GPR43 transcription in adipocytes is XBP1 independent. (a–d) IM-BAT adipocytes transfected with control siRNA or XBP1 siRNA were differentiated in the absence or in the presence of rosiglitazone (1 μM) during differentiation from day 3 to day 5 after differentiation. Accumulated lipids in the siRNA transfected IM-BAT adipocytes were measured by Oil Red O staining (a), while mRNA levels of XBP1 (b), GPR43 (c), and aP2 (d) in the transfected IM-BAT adipocytes were measured by quantitative real-time PCR. Data are expressed as mean ± SEM (). ; ;   by one-way ANOVA followed by Student’s -test. (e) Agarose gel of undifferentiated IM-BAT adipocytes treated with rosiglitazone (1 μM) for 6 h. Splicing of XBP1 mRNA was detected by RT-PCR. cDNA from preadipocytes treated with tunicamycin was used as positive control.

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