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. Author manuscript; available in PMC: 2014 Sep 2.
Published in final edited form as: Mech Ageing Dev. 2013 Sep 2;134(9):10.1016/j.mad.2013.08.003. doi: 10.1016/j.mad.2013.08.003

Fig.4. Activation of RXRα enhances FXR-mediated transactivation of Abcb1a promoter.

Fig.4

A. Over-expression of RXRα enhanced FXR-mediated transactivation of Abcb1a promoter. Abcb1a promoter-reporter construct was co-transfected with FXR or RXRα expression plasmids into Hep3B2 cells. Sixteen hours later, the cell cultures were treated with vehicle (DMSO), CDCA (100 µM) or GW4064 (2 µM) for 24 hours and harvested for luciferase reporter assay.

B. LG100268 increased GW4064-induced Abcb1a promoter activity in the presence of exogenous FXR and RXRα.Abcb1a promoter-reporter constructs were co-transfected with FXR or RXRα expression plasmids into Hep3B2 cells. Sixteen hours later, the cell cultures were treated with GW4064 (1 µM) or both GW4064 (1 µM) and LG100268 (0.5 µM) for 24 hours and harvested for reporter assay.

C. RXRα bound to Abcb1a promoter in vivo. The chromatin fraction from the liver of a Little mouse was used in ChIP assay with indicated antibodies. PCR was performed with primers covering the putative binding site in the promoter of Abcb1a. Primers covering a known IR1 found in the promoter of Nr0b2 were used as positive control.