In vitro protection of auditory hair cells by salicylate from the gentamicin-induced but not neomycin-induced cell loss

• Published in: Neuroscience letters 2012-01, Vol.506 (1), p.107-110
• Main Authors: Mazurek, Birgit, Lou, Xiangxin, Olze, Heidi, Haupt, Heidemarie, Szczepek, Agnieszka J.
• Format: Article
• Language: English
• Subjects: Animals; Animals, Newborn; Anti-Inflammatory Agents, Non-Steroidal - pharmacology; Cell Count; Cell Death - drug effects; Cochlea - cytology; Dose-Response Relationship, Drug; Drug Interactions; Gentamicin; Gentamicins - toxicity; Hair cells; Hair Cells, Auditory - drug effects; Neomycin; Neomycin - toxicity; Organ Culture Techniques; Otoprotection; Protein Synthesis Inhibitors - toxicity; Rats; Salicylate; Salicylates - pharmacology
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2011.10.060

► Salicylate used at the concentration of 10 mM induces inner but not outer hair cell loss. ► Salicylate protects in vitro from gentamicin-induced auditory hair cell loss. ► Salicylate does not protect in vitro from neomycin-induced auditory hair cell loss. Salicylate has been shown to protect animals and people from the gentamicin-induced hearing loss. The objective of our study was to determine if salicylate is otoprotective in vitro. In this fashion, we wanted to validate the use of explant culture system for future studies on the ototoxicity prevention. In addition, we wanted to find out if salicylate protects from the ototoxicity of other aminoglycosides. As a model, we used the membranous cochlear tissues containing the organ of Corti, spiral limbus and spiral ganglion neurons dissected from the cochleas of p3–p5 Wistar pups. The explants were divided into apical, medial and basal parts and cultured in presence or absence of 100 μM gentamicin, 100 μM neomycin and 5 mM salicylate. Following the tissue fixation and staining with phalloidin–TRITC, the number of inner and outer hair cells (IHCs, OHCs) was scored under the fluorescent microscope. Presence of 5 mM salicylate in explants cultures exposed to 100 μM gentamicin significantly reduced the loss of IHCs and OHCs, as compared to explants exposed to gentamicin alone. In contrast, neomycin-induced auditory hair cell loss remained unaffected by the presence of salicylate. Our results corroborate earlier in vivo findings and validate the use of cochlear explants for future studies on ototoxicity and its prevention. Moreover, the inability of salicylate to prevent neomycin-induced ototoxicity implies possible differences between the mechanisms of auditory hair cell loss induced by gentamicin and neomycin.