Farnesoid X receptor (FXR) agonists can reverse dysregulated bile acid metabolism thus are potential therapeutics to prevent and treat non-alcoholic fatty liver disease. The low success rate of FXR agonists R&D and the side effects of the clinical candidates such as obeticholic acid make it urgent to discover new chemotypes. Unfortunately, structure-based virtual screening (SBVS) that can speed up drug discovery had rarely been reported with success for FXR, which was likely hindered by the failure in addressing protein flexibility. To address this issue, we devised human FXR- (hFXR-) specific ensemble learning models based on pose filters from 24 agonist-bound hFXR crystal structures and coupled them to traditional SBVS approaches of FRED docking plus Chemgauss4 scoring function. It turned out that hFXR-specific pose filters ensemble (PFE) was able to improve ligand enrichment significantly, which rendered 3RUT-based SBVS with its PFE as the ideal approach for FXR agonists discovery. By screening of the Specs chemical library and in vitro FXR transactivation bioassay, we identified a new class of FXR agonists with compound XJ034 as the representative, which would have been missed if the PFE was not coupled to. Following that, we performed in-depth biological studies which demonstrated that XJ034 resulted in a downtrend of intracellular triglyceride in vitro, significantly decreased the serum/liver TG in high fat diet-induced C57BL/6J obese mice, and more importantly, showed metabolic stabilities in both plasma and liver microsomes. To provide insight into further structure-based lead optimization, we solved the crystal structure of hFXR complexed with compound XJ034 that uncovers a unique hydrogen bond between compound XJ034 and residue Y375. The current work highlights the power of our pose filter-based ensemble learning approach in term of scaffold hopping and provides a promising lead compound for further development.
September 28, 2018
Anastrozole plus fulvestrant vs. anastrozole alone for hormone receptor-positive advanced breast cancer: a meta-analysis of randomized controlled trials.
February 4, 2020