Clin Exp Otorhinolaryngol.  2014 Dec;7(4):275-280. 10.3342/ceo.2014.7.4.275.

Dexmedetomidine Preconditioning Attenuates Cisplatin-Induced Ototoxicity in Zebrafish

• Min TJ
• Kim WY
• Ha YR
• Jeong IY
• Yoo JY

• KMID: 2278367
• DOI: http://doi.org/10.3342/ceo.2014.7.4.275

Abstract

OBJECTIVES
Utilisation of high-frequency drills is known to increase noise induced hearing loss due to increasing the damages of inner ear cells. This study aimed to investigate whether preconditioning by using dexmedetomidine (DEX) decreased the occurrence of ischemia in inner cells of the ear.
METHODS
We utilised a transgenic zebrafish line Brn3C, and the embryos were collected from breeding adult zebrafish. Five-day-old larvae were cultured at the density of 50 embryos, and the larvae were classified into 4 groups: control, cisplatin group, DEX group, and DEX+yohimbine; adrenoreceptor blocker group. The DEX group was categorised into 3 subgroups by dosage; 0.1, 1, and 10 microM. Preconditioning was performed for 150 minutes and then exposed to cisplatin for 6 hours. The experiment was performed in 7 replicates for each group and the number of hair cells in 3 parts of the neuromasts of each fish was determined.
RESULTS
Hair cell apoptosis by cisplatin was attenuated more significantly in the DEX preconditioning group than in the control group. However, the preconditioning effects were not blocked by yohimbine.
CONCLUSION
The results of this study suggest that hearing loss caused by vibration-induced noise could be reduced by using DEX and may occur through other mechanisms rather than adreno-receptors.

Keyword

Preconditioning; Dexmedetomidine; Hearing loss

MeSH Terms

Adult
Apoptosis
Breeding
Cisplatin
Dexmedetomidine*
Ear
Ear, Inner
Embryonic Structures
Hair
Hearing Loss
Humans
Ischemia
Larva
Noise
Yohimbine
Zebrafish*
Cisplatin
Dexmedetomidine
Yohimbine

Figure

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  Fig. 1 Experimental protocol. (A) Dexmedetomidine (DEX) preconditioning group. (B) Dexmedetomidine-yohimbine (DEX-YoH) preconditioning group. dpf, days post-fertilization.

• 

  Fig. 2 Immunostain of adrenergic receptor alpha-2. GFP, green fluorescent protein.

• 

  Fig. 3 Observation site of neuromast on zebrafish.

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  Fig. 4 Quantification of zebrafish neuromasts. (A) Hair cell count by fluorescent microscope. (B) The quantification of dexmedetomidine preconditioning effect by hair cell counts. (C) The guantification of yohimbin-blooking effect by cell counts. DEX, dexmedetomidine; YOH, yohimbi.

• 

  Fig. 5 The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay of zebrafishs. Cisplatin-induced apoptotic cells were confirmed by the TUNEL assay. Normal hair cells were marked as green dots. Apoptotic cells were marked as light red dots (arrows) in red-colored fish after TUNEL reaction under a fluorescent microscope. The preconditioning of 10 µM dexmedetomidine significantly decreased the TUNEL reaction and protected the hair cells in the transgenic zebrafish from apoptotic cell death. (A) Control, (B) 1 mM cisplatine (6 hours), (C) 10 µM dexmedetomidine precondition (2.5 hours), 1 mM cisplatine (6 hours), (D) 100 µM yohimbine+10 µM dexmedetomidin precondition (2.5 hours), 1 mM cisplatine (6 hours).

Reference

1. Urquhart AC, McIntosh WA, Bodenstein NP. Drill-generated sensorineural hearing loss following mastoid surgery. Laryngoscope. 1992; 6. 102(6):689–692. PMID: 1602918.

2. Farzanegan G, Ghasemi M, Panahi F, Raza M, Alghasi M. Does drill-induced noise have an impact on sensorineural hearing during craniotomy procedure? Br J Neurosurg. 2010; 2. 24(1):40–45. PMID: 20158351.

3. Hong SJ, Im GJ, Chang J, Chae SW, Lee SH, Kwon SY, et al. Protective effects of edaravone against cisplatin-induced hair cell damage in zebrafish. Int J Pediatr Otorhinolaryngol. 2013; 6. 77(6):1025–1031. PMID: 23628221.

4. Choi J, Im GJ, Chang J, Chae SW, Lee SH, Kwon SY, et al. Protective effects of apocynin on cisplatin-induced ototoxicity in an auditory cell line and in zebrafish. J Appl Toxicol. 2013; 2. 33(2):125–133. PMID: 22147442.

5. Ma D, Hossain M, Rajakumaraswamy N, Arshad M, Sanders RD, Franks NP, et al. Dexmedetomidine produces its neuroprotective effect via the alpha 2A-adrenoceptor subtype. Eur J Pharmacol. 2004; 10. 502(1-2):87–97. PMID: 15464093.

6. Engelhard K, Werner C, Eberspacher E, Bachl M, Blobner M, Hildt E, et al. The effect of the alpha 2-agonist dexmedetomidine and the N-methyl-D-aspartate antagonist S(+)-ketamine on the expression of apoptosis-regulating proteins after incomplete cerebral ischemia and reperfusion in rats. Anesth Analg. 2003; 2. 96(2):524–531. PMID: 12538207.

7. Sanders RD, Sun P, Patel S, Li M, Maze M, Ma D. Dexmedetomidine provides cortical neuroprotection: impact on anaesthetic-induced neuroapoptosis in the rat developing brain. Acta Anaesthesiol Scand. 2010; 7. 54(6):710–716. PMID: 20003127.

8. Sanders RD, Xu J, Shu Y, Januszewski A, Halder S, Fidalgo A, et al. Dexmedetomidine attenuates isoflurane-induced neurocognitive impairment in neonatal rats. Anesthesiology. 2009; 5. 110(5):1077–1085. PMID: 19352168.

9. Wang J, Meng F, Cottrell JE, Kass IS. The differential effects of volatile anesthetics on electrophysiological and biochemical changes during and recovery after hypoxia in rat hippocampal slice CA1 pyramidal cells. Neuroscience. 2006; 7. 140(3):957–967. PMID: 16580780.

10. Lee HT, Ota-Setlik A, Fu Y, Nasr SH, Emala CW. Differential protective effects of volatile anesthetics against renal ischemia-reperfusion injury in vivo. Anesthesiology. 2004; 12. 101(6):1313–1324. PMID: 15564938.

11. Dahmani S, Paris A, Jannier V, Hein L, Rouelle D, Scholz J, et al. Dexmedetomidine increases hippocampal phosphorylated extracellular signal-regulated protein kinase 1 and 2 content by an alpha 2-adrenoceptor-independent mechanism: evidence for the involvement of imidazoline I1 receptors. Anesthesiology. 2008; 3. 108(3):457–466. PMID: 18292683.

12. Steele SL, Yang X, Debiais-Thibaud M, Schwerte T, Pelster B, Ekker M, et al. In vivo and in vitro assessment of cardiac beta-adrenergic receptors in larval zebrafish (Danio rerio). J Exp Biol. 2011; 5. 214(Pt 9):1445–1457. PMID: 21490253.

13. Takeda S, Hata R, Cao F, Yoshida T, Hakuba N, Hato N, et al. Ischemic tolerance in the cochlea. Neurosci Lett. 2009; 10. 462(3):263–266. PMID: 19596048.

14. Cason BA, Gamperl AK, Slocum RE, Hickey RF. Anesthetic-induced preconditioning: previous administration of isoflurane decreases myocardial infarct size in rabbits. Anesthesiology. 1997; 11. 87(5):1182–1190. PMID: 9366471.

15. Kevin LG, Novalija E, Riess ML, Camara AK, Rhodes SS, Stowe DF. Sevoflurane exposure generates superoxide but leads to decreased superoxide during ischemia and reperfusion in isolated hearts. Anesth Analg. 2003; 4. 96(4):949–955. PMID: 12651639.

16. Hensley K, Robinson KA, Gabbita SP, Salsman S, Floyd RA. Reactive oxygen species, cell signaling, and cell injury. Free Radic Biol Med. 2000; 5. 28(10):1456–1462. PMID: 10927169.

17. Ljubkovic M, Mio Y, Marinovic J, Stadnicka A, Warltier DC, Bosnjak ZJ, et al. Isoflurane preconditioning uncouples mitochondria and protects against hypoxia-reoxygenation. Am J Physiol Cell Physiol. 2007; 5. 292(5):C1583–C1590. PMID: 17215328.

18. Rybak LP, Kelly T. Ototoxicity: bioprotective mechanisms. Curr Opin Otolaryngol Head Neck Surg. 2003; 10. 11(5):328–333. PMID: 14502062.

19. Rybak LP. Mechanisms of cisplatin ototoxicity and progress in otoprotection. Curr Opin Otolaryngol Head Neck Surg. 2007; 10. 15(5):364–369. PMID: 17823555.

20. Kovacic P, Somanathan R. Ototoxicity and noise trauma: electron transfer, reactive oxygen species, cell signaling, electrical effects, and protection by antioxidants: practical medical aspects. Med Hypotheses. 2008; 70(5):914–923. PMID: 17977665.

21. Ruuskanen JO, Peitsaro N, Kaslin JV, Panula P, Scheinin M. Expression and function of alpha-adrenoceptors in zebrafish: drug effects, mRNA and receptor distributions. J Neurochem. 2005; 9. 94(6):1559–1569. PMID: 16000146.

22. Chang Y, Huang X, Liu Z, Han G, Huang L, Xiong YC, et al. Dexmedetomidine inhibits the secretion of high mobility group box 1 from lipopolysaccharide-activated macrophages in vitro. J Surg Res. 2013; 5. 181(2):308–314. PMID: 22939552.