Figure 4.
Effect of NNRTIs on transactivation of the LBD of hCAR-WT. Cultured HepG2 cells were transfected with pFR-luc reporter plasmid, pGL4.74 [hRluc/TK] internal control plasmid, and either the pM-hCAR-WT-LBD receptor expression plasmid or the pM empty vector for 24 h. Transfected HepG2 cells were treated with DMSO (0.1% v v−1; vehicle control), rilpivirine (RPV; 5 μM), etravirine (ETV; 5 μM), efavirenz (EFV; 5 μM), nevirapine (NVP; 5 μM), delavirdine (DLV; 5 μM), TCPOBOP (0.25 μM; negative control), or CITCO (10 μM; positive control) for 24 h. In all cases, cells were co-treated with androstanol (10 μM; inverse agonist for hCAR-WT) to decrease the constitutive activity of this receptor. Firefly luciferase and R. reniformis luciferase activities were measured and normalized as described under Methods. Data are expressed as mean ± SEM for three independent experiments performed in triplicate. *Significantly different from the same treatment group transfected with the empty vector and from the vehicle-treated control cells transfected with receptor expression plasmid (P < 0.05). Androstanol reduced the constitutive activity of hCAR-WT by 30 ± 19%.