A cell-based high-throughput screening assay for Farnesoid X receptor agonists.

Objective: To develop a high-throughput screening assay for Farnesoid X receptor (FXR) agonists based on mammalian one-hybrid system (a chimera receptor gene system) for the purpose of identifying new lead compounds for dyslipidaemia drug from the chemical library.

Methods: cDNA encoding the human FXR ligand binding domain (LBD) was amplified by RT-PCR from a human liver total mRNA and fused to the DNA binding domain (DBD) of yeast GAL4 of pBIND to construct a GAL4-FXR (LBD) chimera expression plasmid. Five copies of the GAL4 DNA binding site were synthesized and inserted into upstream of the SV40 promoter of pGL3-promoter vector to construct a reporter plasmid pG5-SV40 Luc. The assay was developed by transient co-transfection with pG5-SV40 Luc reporter plasmid and pBIND-FXR-LBD (189-472) chimera expression plasmid.

Results: After optimization, CDCA, a FXR natural agonist, could induce expression of the luciferase gene in a dose-dependent manner, and had a signal/noise ratio of 10 and Z' factor value of 0.65.

Conclusion: A stable and sensitive cell-based high-throughput screening model can be used in high-throughput screening for FXR agonists from the synthetic and natural compound library.