Study of the Mechanisms by Which Aminoglycoside Damage Is Prevented in Chick Embryonic Hair Cells
A major side effect of aminoglycoside antibiotics is mammalian hair cell death. It is thus intriguing that embryonic chick hair cells treated with aminoglycosides at embryonic day (E) 12 are insensitive to ototoxicity. To exclude some unknown factors in vivo that might be involved in preventing aminoglycoside damage to embryonic hair cells, we first cultured chick embryonic basilar papilla (BP) with an aminoglycoside antibiotic in vitro. The results indicated that the hair cells were almost intact at E12 and E14 and were only moderately damaged in most parts of the BP at E16 and E18. Generally, hair cells residing in the approximate and abneural regions were more susceptible to streptomycin damage. After incubation with gentamicin-conjugated Texas Red (GTTR), which is typically used to trace the entry route of aminoglycosides, GTTR fluorescence was not remarkable in hair cells at E12, was weak at E14, but was relatively strong in the proximal part of BP at E18. This result indicates that the amounts of GTTR that entered the hair cells are related to the degrees of aminoglycoside damage. The study further showed that the fluorescence intensity of GTTR decreased to a low level at E14 to E18 after disruption of mechanotransduction machinery, suggesting that the aminoglycoside entry into hair cells was mainly through mechanotransduction channels. In addition, most of the entered GTTR was not found to be colocalized with mitochondria even at E18. This finding provides another reason to explain why embryonic chick hair cells are insensitive to aminoglycoside damage.
Keywordsantibiotic toxicity mechanotransduction channels transient receptor potential ion channel chicken cochlea mitochondria
Gentamicin-conjugated Texas Red
Transient receptor potential (TRP) ion channel 1
2-bis (o-aminophenoxy) ethane-N, N, N′, N′-tetra-acetic acid
(N- (3-triethylammoniumpropyl)- 4- (4-(dibutylamino) styryl) pyridiniumdibromide
We thank Dr. Jin-Liu in the Experimental Technology Center for Life Sciences and the College of Life Sciences, Beijing Normal University, for technological assistance.
This work was supported by the National Natural Science Foundation of China through grants to ZM Han (No. 81371352), SJ Zeng (Nos. 31672283 and 31372200), XW Zhang (No. 31560275 and 31360517), and XB Zhang (No. 31360243).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no competing interests.
- Bryant JE, Marcotti W, Kros CJ, Richardson GP (2003) FM1–43 enters hair cells from the onset of mechano-electrical transduction in both mouse and chick cochlea. In: Proc. Midwinter Meeting. Association for Research in OtolaryngologyGoogle Scholar
- Corey DP, Jaime GA, Holt JR, Kwan KY, Lin SY, Vollrath MA, Amalfitano A, Cheung ELM, Derfler BH, Duggan A, Gray PA, Hoffman MP, Rehm HL, Tamasauskas D, Zhang DS (2004) TRPA1 is a candidate for the mechanosensitive transduction channel of vertebrate hair cells. Nature 432:723–730CrossRefPubMedGoogle Scholar
- Kurima K, Peters LM, Yang Y, Riazuddin S, Ahmed ZM, Naz S, Arnaud D, Drury S, Mo J, Makishima T, Ghosh M, Menon PS, Deshmukh D, Oddoux C, Ostrer H, Khan S, Deininger PL, Hampton LL, Sullivan SL, Battey JF, Keats BJ Jr, Wilcox ER, Friedman TB, Griffith AJ (2002) Dominant and recessive deafness caused by mutations of a novel gene, TMC1, required for cochlear hair cell function. Nat Genet 30:277–284CrossRefPubMedGoogle Scholar
- Lim DJ, Anniko M (1985) Developmental morphology of the mouse inner ear. A scanning electron microscopic observation. Acta Otolaryngol 422:1–69Google Scholar
- Luk L, Aharazneh A, Naeem T, Monfared A, Steyger P, Cheng A, Ricci A (2010) Aminoglycosides rapidly and selectively enter hair cells, largely via mechanotransducer channels. 33rd Annual MidWinter Research Meeting of the Association for Research in OtolaryngologyGoogle Scholar
- Wang Z, Liou L (1994) Auditory effect of kanamycin given to newborn guinea pigs whose mothers received kanamycin during pregnancy. Ann Otol Rhinol Laryngol 103:983–985Google Scholar