MKP-1 is required for 1,25-(OH)2D3-induced RXRα nuclear import. A, Representative Western blot of cytoplasmic/nuclear expression of VDR and RXRα from BMSC treated with 10−7
m 1,25-(OH)2D3 for 1 h. B, Densitometric quantification of RXRα and VDR protein levels normalized to GAPDH or lamin A/C. C, Densitometric comparison of VDR and RXRα nuclear import in primary WT and MKP-1−/− BMSC and total relative VDR and RXRα present in nuclear and cytoplasmic fractions. D, Immunofluorescence cytochemistry of WT and MKP-1−/− BMSC for RXRα and VDR protein localization. White scale bar, 10 μm. (n = 3; *, P < 0.05). Ctrl, Control; Veh, vehicle.