Compositions and methods for the modulation of the corticotropin releasing factor binding protein and the treatment of alcohol use disorder

Stress responses involve corticotropin releasing factor (CRF), the two cognate receptors (CRF 1 and CRF 2 ) and the CRF-binding protein (CRFBP). Utilizing a novel cell-based assay, a C-terminal CRFBP fragment [CRFBP(10 kD)] was found to potentiates CRF-intracellular Ca 2+ release, demonstrating that CRFBP possesses excitatory roles in addition to the inhibitory role established by the N-terminal fragment of CRFBP [CRFBP(27 kD)]. This interaction was CRF 2 -specific, as CRF 1 responses were not potentiated by CRFBP(10 kD). As there were currently no small molecule ligands available that selectively interact with either CRFBP or CRF 2 , a cell-based assay was miniaturized, wherein CRFBP(10 kD) was fused as a chimera with CRF 2α , that allowed us to a perform a high-throughput screen (HTS) of approximately 350,000 small molecules. This resulted in the identification of negative allosteric modulators (NAMs) of the CRFBP(10 kD)-CRF 2 complex that blunt CRF-induced potentiation of N-Methyl-D-aspartic acid receptor (NMDAR)-mediated synaptic transmission in dopamine neurons in the ventral tegmental area (VTA). These results provide the first evidence of specific roles for CRF 2 and CRFBP in the modulation of neuronal activity and suggest that NMDARs in the VTA may be a target for the treatment of stress and substance abuse disorders such as alcohol use disorder.