Design of a Potent TLX Agonist by Rational Fragment Fusion

As a master regulator of neurogenesis, the Orphan Nuclear Receptor tailless homologue (TLX, NR2E1) maintains neuronal stem cell homeostasis by acting as a transcriptional repressor of tumor suppressor genes. It is hence considered as an appealing target for the treatment of neurodegenerative diseases, but a lack of potent TLX modulators as tools to probe pharmacological TLX control hinders further validation of its promising potential. Here, we report the development of a potent TLX agonist based on fragment screening, pharmacophore modeling, and fragment fusion. Pharmacophore similarity of a fragment screening hit and the TLX ligand ccrp2 provided a rational basis for fragment linkage, which resulted in several TLX activator scaffolds. Among them, the fused compound 10 evolved as a valuable TLX agonist tool with submicromolar potency and high selectivity over related nuclear receptors, rendering it suitable for functional studies on TLX.