Work

Development and use of a high-throughput screen to identify novel modulators of the corticotropin releasing factor binding protein

Year: 2022
Type: article
Abstract: Background Stress responses are believed to involve corticotropin releasing factor (CRF), its two cognate receptors (CRF 1 and CRF 2 ), and the CRF-binding protein (CRFBP). Whereas decades of research has focused on CRF 1 , the role of CRF 2 in the central nervous system (CNS) has not been thoroughly investigated. We have previously reported that CRF 2 , interacting with a C terminal fragment of CRFBP, CRFBP(10kD), may have a role in the modulation of neuronal activity. However, the mechanism by which CRF interacts with CRFBP(10kD) and CRF 2 has not been fully elucidated due to the lack of useful chemical tools to probe CRFBP. Methods We miniaturized a cell-based assay, where CRFBP(10kD) is fused as a chimera with CRF 2 , and performed a high-throughput screen (HTS) of 350,000 small molecules to find negative allosteric modulators (NAMs) of the CRFBP(10kD)-CRF 2 complex. Hits were confirmed by evaluating activity toward parental HEK293 cells, toward CRF 2 in the absence of CRFBP(10kD), and toward CRF 1 in vitro. Hits were further characterized in ex vivo electrophysiology assays that target: 1) the CRF 1 + neurons in the central nucleus of the amygdala (CeA) of CRF1:GFP mice that express GFP under the CRF 1 promoter, and 2) the CRF-induced potentiation of N -methyl-D-aspartic acid receptor (NMDAR)-mediated synaptic transmission in dopamine neurons in the ventral tegmental area (VTA). Results We found that CRFBP(10kD) potentiates CRF-intracellular Ca 2+ release specifically via CRF 2 , indicating that CRFBP may possess excitatory roles in addition to the inhibitory role established by the N-terminal fragment of CRFBP, CRFBP(27kD). We identified novel small molecule CRFBP-CRF 2 NAMs that do not alter the CRF 1 -mediated effects of exogenous CRF but blunt CRF-induced potentiation of NMDAR-mediated synaptic transmission in dopamine neurons in the VTA, an effect mediated by CRF 2 and CRFBP. Conclusion These results provide the first evidence of specific roles for CRF 2 and CRFBP(10kD) in the modulation of neuronal activity and suggest that CRFBP(10kD)-CRF 2 NAMs can be further developed for the treatment of stress-related disorders including alcohol and substance use disorders.
Language: English
Open Access status: gold
Estimated APC paid: $1,800
OpenAlex ID: W4302774206
FWCI: 0.093
Cites: 53
Cited by: 1
Related to: 10