High-throughput screening in larval zebrafish identifies novel potent sedative-hypnotics
Files
Accepted manuscript
Date
2018-09-01
Authors
Yang, Xiaoxuan
Jounaidi, Youssef
Dai, Jennifer B.
Marte-Oquendo, Francisco
Halpin, Elizabeth S.
Brown, Lauren E.
Trilles, Richard
Xu, Wenqing
Daigle, Renee
Yu, Buwei
Version
Accepted manuscript
Embargo Date
2019-08-31
OA Version
Citation
Xiaoxuan Yang, Youssef Jounaidi, Jennifer B Dai, Francisco Marte-Oquendo, Elizabeth S Halpin, Lauren E Brown, Richard Trilles, Wenqing Xu, Renee Daigle, Buwei Yu, Scott E Schaus, John A Porco, Stuart A Forman. 2018. "High-throughput Screening in Larval Zebrafish Identifies Novel Potent Sedative-hypnotics." Anesthesiology, Volume 129, Issue 3, pp. 459 - 476 (18). https://doi.org/10.1097/ALN.0000000000002281
Abstract
BACKGROUND: Many general anesthetics were discovered empirically, but primary screens to find new sedative-hypnotics in drug libraries have not used animals, limiting the types of drugs discovered. The authors hypothesized that a sedative-hypnotic screening approach using zebrafish larvae responses to sensory stimuli would perform comparably to standard assays, and efficiently identify new active compounds.
METHODS:
The authors developed a binary outcome photomotor response assay for zebrafish larvae using a computerized system that tracked individual motions of up to 96 animals simultaneously. The assay was validated against tadpole loss of righting reflexes, using sedative-hypnotics of widely varying potencies that affect various molecular targets. A total of 374 representative compounds from a larger library were screened in zebrafish larvae for hypnotic activity at 10 µM. Molecular mechanisms of hits were explored in anesthetic-sensitive ion channels using electrophysiology, or in zebrafish using a specific reversal agent.
RESULTS:
Zebrafish larvae assays required far less drug, time, and effort than tadpoles. In validation experiments, zebrafish and tadpole screening for hypnotic activity agreed 100% (n = 11; P = 0.002), and potencies were very similar (Pearson correlation, r > 0.999). Two reversible and potent sedative-hypnotics were discovered in the library subset. CMLD003237 (EC50, ~11 µM) weakly modulated γ-aminobutyric acid type A receptors and inhibited neuronal nicotinic receptors. CMLD006025 (EC50, ~13 µM) inhibited both N-methyl-D-aspartate and neuronal nicotinic receptors.
CONCLUSIONS:
Photomotor response assays in zebrafish larvae are a mechanism-independent platform for high-throughput screening to identify novel sedative-hypnotics. The variety of chemotypes producing hypnosis is likely much larger than currently known.