Development of an Aequorin-Based Assay for the Screening of Corticotropin-Releasing Factor Receptor Antagonists

The study developed and optimized an aequorin-based assay for screening corticotropin-releasing factor (CRF) receptor antagonists, which were proposed to influence hair loss and regrowth. Researchers established a stable cell line, HEK293a16/hCRF1, by transfecting aequorin parental cells with CRF1 receptor and alpha 16 promiscuous G protein cDNA. This cell line showed a 12-fold higher dose response to sauvagine compared to transiently expressed cells, ensuring robust signals and high solvent tolerance for antagonist screening. Standard CRF1 receptor antagonists, antalarmin and CP154526, showed $IC_{50}$ values of 414.1±5.5 nM and 290.7±1.9 nM, respectively, with similar results in frozen cells. The HEK293a16/hCRF1 cells with the aequorin-based assay could serve as a model for developing functional cosmetics and modulators with potential clinical efficacy on hair regrowth.