To screen for compounds that protect hair cells against ototoxic drugs, only minor modifications are necessary to our toxicity screens.
Our initial screens for hair cell protectants were designed to identify compounds that conferred robust protection to neomycin-treated hair cells [26].
We initially focused on small molecules within the Chembridge Diverset E library.
To efficiently screen a sample of 10,960 compounds from the library, compounds were multiplexed five per well and then reassessed individually when protection was observed.
Two compounds, PROTO1 and PROTO2, exhibited robust protection of lateral line hair cells over a broad range of neomycin concentrations.
Further testing of these compounds in mice revealed that they also protected hair cells in neomycintreated utricular explants, validating the zebrafish lateral line as a model for discovery of novel otoprotective drugs.
Both PROTO1 and PROTO2 are related benzothiophene carboximides, raising the possibility that they may confer their protective effects through action on the same target.