Automated High-Throughput Damage Scoring of Zebrafish Lateral Line Hair Cells After Ototoxin Exposure

Abstract

Zebrafish have emerged as a powerful biological system for drug development against hearing loss. Zebrafish hair cells, contained within neuromasts along the lateral line, can be damaged with exposure to ototoxins, and therefore, pre-exposure to potentially otoprotective compounds can be a means of identifying promising new drug candidates. Unfortunately, anatomical assays of hair cell damage are typically low-throughput and labor intensive, requiring trained experts to manually score hair cell damage in fluorescence or confocal images. To enhance throughput and consistency, our group has developed an automated damage-scoring algorithm based on machine-learning techniques that produce accurate damage scores, eliminate potential operator bias, provide more fidelity in determining damage scores that are between two levels, and deliver consistent results in a fraction of the time required for manual analysis. The system has been validated against trained experts using linear regression, hypothesis testing, and the Pearson's correlation coefficient. Furthermore, performance has been quantified by measuring mean absolute error for each image and the time taken to automatically compute damage scores. Coupling automated analysis of zebrafish hair cell damage to behavioral assays for ototoxicity produces a novel drug discovery platform for rapid translation of candidate drugs into preclinical mammalian models of hearing loss.

Use of Zebrafish in Drug Discovery Toxicology

“…Several screening platforms were recently tested and proven useful for detecting hair cell damage. − Using platforms such as these, many potentially protective cotreatments have been discovered in zebrafish that may mitigate human ototoxicity of useful, and yet unimproved, therapeutics. Some methods, through live imaging and forward genetic screens, can provide insight into the chemical and genetic mechanisms of ototoxicity as well as information about whether a protective cotreatment interferes with the therapy .…”

Hair cell toxicology: With the help of a little fish

“…Nevertheless, this study had some limitations, as it tested only one relatively short exposure time (1 h) and some ototoxins need more time to cause detectable hair cell damage; precisely one of such is gentamicin, which failed to test positive in this screen. Automation of the inspection of stained hair cells would allow to refine such high throughput screening process to acquire more sensitivity ( Philip et al, 2018 ).…”

Emerging Therapies and Approaches to Treat and Prevent Hearing Loss

“…Table 3 includes a list of zebrafish models of human genetic hearing loss. Lastly, for the purposes of pharmacological studies, many high-throughput and automated assessments for hearing research have been developed for rapid screening (Bang et al, 2002;Ou et al, 2010;Pei et al, 2018;Philip et al, 2018;Taylor et al, 2010;Todd et al, 2017) .…”