The modulators of farnesoid X receptor (FXR), a bile acid receptor, regulate various biological processes including bile acid metabolism, and are associated with the control of fatty liver and osteoporosis. Thus, the control of FXR activity and development of FXR modulators are critical not only for research, but also for clinical application. In this study, we synthesized novel FXR agonists 1–4 possessing isoxazole and N-substituted benzimidazole moieties, and compared their effects on osteoblast differentiation with the known FXR agonists, chenodeoxycholic acid and a synthetic compound, GW4064. Two (3 and 4) of the four novel FXR agonists 1–4 showed high specificities for FXR. Computer-assisted modeling suggested that the binding of the FXR agonist 3 with ligand binding domain of FXR was similar to GW4064. FXR was expressed in mouse bone marrow-derived mesenchymal stem cell (MSC)-like ST2 cells (ST-2 MSCs). The FXR agonists activated the BMP-2-induced differentiation of ST-2 MSCs into osteoblasts and enhanced the expression of RUNX2. Moreover, the potency of the FXR agonist 3 was comparable to GW4064 in promoting osteoblast differentiation of ST-2 MSCs. These results indicate that FXR activation enhanced the BMP-2-induced differentiation of MSCs into osteoblasts through activating RUNX2 expression. FXR could be a potential therapeutic target for the treatment of bone diseases such as osteoporosis.
法尼索尔X受体(FXR)的调节剂,一种胆酸受体,调节包括胆酸代谢在内的各种生物过程,并与控制脂肪肝和骨质疏松有关。因此,不仅对于研究,而且对于临床应用来说,控制FXR活性和开发FXR调节剂至关重要。在这项研究中,我们合成了具有异噁唑和N-取代苯并咪唑基团的新型FXR激动剂1-4,并将它们与已知的FXR激动剂,烯二氧胆酸和合成化合物GW4064的效果进行了比较。四种新型FXR激动剂1-4中的两种(3和4)显示出对FXR的高特异性。计算机辅助建模表明,FXR激动剂3与FXR的配体结合结构域的结合类似于GW4064。FXR在小鼠骨髓来源的间充质干细胞(MSC)样ST2细胞(ST-2 MSCs)中表达。FXR激动剂激活了BMP-2诱导的ST-2 MSCs向成骨细胞的分化,并增强了RUNX2的表达。此外,FXR激动剂3在促进ST-2 MSCs成骨细胞分化方面的效力与GW4064相当。这些结果表明,FXR激活通过激活RUNX2表达增强了BMP-2诱导的MSCs向成骨细胞的分化。FXR可能是治疗骨质疏松等骨疾病的潜在治疗靶点。