FIG 4.

FHL2 acts as a coactivator of LXRs. (A and B) FHL2 enhances the activity of LXRα (A) and LXRβ (B) on the LXRE-luciferase reporter. LXR activity was further enhanced by two synthetic LXR ligands, T0901317 and GW3965. *, P ≤ 0.05, compared to control; **, P ≤ 0.05, compared to LXR α or LXRβ. (C and D) Effect of distinct FHL2 mutants on transcriptional activity of LXRα (C) or LXRβ (D) on the LXRE-luciferase reporter was assayed. (E and F) WT and FHL2-KO SMCs were transfected with indicated reporter plasmid. In FHL2-KO SMCs LXR activity is reduced on LXRE-reporter plasmids (E) and ABCA-1 promoter-reporter plasmids (F). (G) FHL2 increased LXR-mediated transcription of an ABCA1 promoter-reporter plasmid, unless the DR4 element was mutated in the ABCA1 promoter-reporter plasmid in HeLa cells. In all luciferase experiments, the transfection efficiency was normalized using Renilla luciferase, which was cotransfected with the reporter plasmids. (H) ChIP analyses were performed with ABCG1 promoter-specific PCR primers and with FLAG antibody following overexpression of LXRβ and FHL2 and pretreatment with GW3965 in HeLa cells. All experiments were performed in triplicate and repeated at least three times. Values are means and SD. *, P ≤ 0.05.