Cochlear lateral wall changes secondary to hypercholesterolemia and noise exposure in the chinchilla model

Year 2024, , 121 - 127, 25.10.2024

Nevra Keskin Yılmaz , Rafael Da Costa Monsanto

https://doi.org/10.47748/tjvr.1484775

Abstract

Objective: To investigate the effects of hypercholesterolemia on the cochlear lateral wall structures in chinchillas and its impact on the susceptibility of the inner ear structures to noise exposure.
Materials and Methods: Fifteen chinchilla temporal bones were selected from the Animal Temporal Bone Collection of the Paparella Otopathology and Pathogenesis Laboratory at the University of Minnesota. The experimental group was subjected to 3-month 1% cholesterol diet, while the control group maintained a standard diet. After 3 months, the experimental group's left ears exposed to noise trauma for 10 minutes while right ears did not. One month later the animals were euthanized, and the temporal bones harvested from the animals underwent histopathological examination with morphometric assessments of stria vascularis (SV) and spiral ligament (SL).
Results: Histopathological analysis revealed no significant differences (p > 0.05) in total SL area across cochlear turns between the experimental and control groups. However, distinct variations were observed in SV area within the lower basal (p<0.01) and upper basal (p = 0.01) turns of the hypercholesterolemia and noise-exposed group compared to the control group.
Conclusion: Hypercholesterolemia is one of the conditions that may contribute to sensorineural hearing loss. This study highlights its importance in auditory health by revealing the relationship between hypercholesterolemia and cochlear lateral wall structures, and increased susceptibility to noise-induced damage.

Keywords

hypercholesterolemia, noise exposure, cochlear lateral wall, chinchilla

Ethical Statement

Studies utilizing our archival collection are University of Minnesota Institutional Review Board and IACUC-exempt, as they originate from previously approved protocols (Decision ID: 00003249).

Project Number

NIH NIDCD U24 DC020851-01, International Hearing Foundation, Lions 5m International, and Scientific and Technological Research Council of Türkiye (TUBITAK) (Scholarship for NKY).

Thanks

Authors would like to thank to Michael M. Paparella, MD and Sebahattin Cureoglu, MD for their support in the study. This study was supported by NIH NIDCD U24 DC020851-01, International Hearing Foundation, Lions 5m International, and Scientific and Technological Research Council of Türkiye (TUBITAK).

References

• Aulbach AD, Amuzie CJ. Biomarkers in nonclinical drug development. In: A comprehensive guide to toxicology in nonclinical drug development. Boston: Academic Press; 2017. pp.447-471. Axelsson A, Lindgren F. Is there a relationship between hypercholesterolaemia and noise-induced hearing loss? Acta Otolaryngol. 1985; 100:379-386.
• Evans MB, Tonini R, Shope CD, et al. Dyslipidemia and auditory function. Otol Neurotol. 2006; 27:609-614.
• Hequembourg S, Liberman MC. Spiral ligament pathology: a major aspect of age-related cochlear degeneration in C57BL/6 Mice. JARO. 2001; 2:118-129.
• Hirose K, Liberman MC. Lateral wall histopathology and endocochlear potential in the noise-damaged mouse cochlea. J Assoc Res Otolaryngol. 2003; 4:339-352.
• Hosoya M, Iwabu K, Kitama T, Nishiyama T, Oishi N, Okano H, et al. Development of cochlear spiral ligament fibrocytes of the common marmoset, a nonhuman model animal. Sci Rep. 2023; 13:11789.
• Kathak RR, Sumon AH, Molla NH, et al. The association between elevated lipid profile and liver enzymes: a study on Bangladeshi adults. Sci Rep. 2022; 12:1711.
• Kusunoki T, Cureoglu S, Schachern PA, Baba K, Kariya S, Paparella MM. Age-related histopathologic changes in the human cochlea: a temporal bone study. Otolaryngol Head Neck Surg. 2004; 13:897-903.
• Lee YY, Ha J, Kim YS, et al. Abnormal Cholesterol Metabolism and Lysosomal Dysfunction Induce Age-Related Hearing Loss by Inhibiting mTORC1-TFEB-Dependent Autophagy. Int J Mol Sci. 2023; 24:17513.
• Liang F, Schulte BA, Qu C, Hu W, Shen Z. Inhibition of the calcium-and voltage-dependent big conductance potassium channel ameliorates cisplatin-induced apoptosis in spiral ligament fibrocytes of the cochlea. Neurosci. 2005; 135:263-271.
• Locher H, de Groot JC, van Iperen L, Huisman MA, Frijns JH, Chuva de Sousa Lopes SM. Development of the stria vascularis and potassium regulation in the human fetal cochlea: Insights into hereditary sensorineural hearing loss. Dev Neurobiol. 2015; 75:1219-1240.
• Mayerl C, Lukasser M, Sedivy R, Niederegger H, Seiler R, Wick G. Atherosclerosis research from past to present--on the track of two pathologists with opposing views, Carl von Rokitansky and Rudolf Virchow. Virchows Arch. 2006; 449:96-103.
• Morizono T, Paparella MM. Hypercholesterolemia and auditory dysfunction. Annals Otol. Rhinol Laryngol. 1978; 87:804-814.
• Morizono T, Sikora MA, Ward WD, Paparella MM, Jorgensen J. Hyperlipidemia and noise in the chinchilla. Acta Otolaryngol. 1985; 99:516-524.
• Morizono T, Sikora MA. Experimental hypercholesterolemia and auditory function in the chinchilla. Otolaryngol Head Neck Surg. 1982; 90:814-818.
• Parhofer KG. Interaction between Glucose and Lipid Metabolism: More than Diabetic Dyslipidemia. Diabetes Metab J. 2015; 39:353-362.
• Peeleman N, Verdoodt D, Ponsaerts P, Van Rompaey V. On the role of fibrocytes and the extracellular matrix in the physiology and pathophysiology of the spiral ligament. Front Neurol. 2020; 11:580639.
• Schmutzhard J, Kositz CH, Glueckert R, Schmutzhard E, Schrott-Fischer A, Lackner P. Apoptosis of the fibrocytes type 1 in the spiral ligament and blood labyrinth barrier disturbance cause hearing impairment in murine cerebral malaria. Malar J. 2012;11: 30.
• Shin SA, Lyu AR, Jeong SH, Kim TH, Park MJ, Park YH. Acoustic trauma modulates cochlear blood flow and vasoactive factors in a rodent model of noise-induced hearing loss. Int J Mol Sci. 2019; 20:5316.
• Sikora MA, Morizono T, Ward WD, Paparella MM, Leslie K. Diet-induced hyperlipidemia and auditory dysfunction. Acta Otolaryngol. 1986; 102:372-381.
• Spicer SS, Schulte BA. The fine structure of spiral ligament cells relates to ion return to the stria and varies with place-frequency. Hear Res. 1996; 100:80-100.
• Stapleton PA, Goodwill AG, James ME, Brock RW, Frisbee JC. Hypercholesterolemia and microvascular dysfunction: interventional strategies. J Inflamm (Lond). 2010; 7:54.
• Wangemann P. Supporting sensory transduction: Cochlear fluid homeostasis and the endocochlear potential. J Physiol. 2006; 576:11-21.
• Yu W, Zong S, Du P, et al. Role of the stria vascularis in the pathogenesis of sensorineural hearing loss: a narrative review. Front Neurosci. 2021; 15:774585.
• Zhang G, Zheng H, Pyykko I, Zou J. The TLR-4/NF-kappaB signaling pathway activation in cochlear inflammation of rats with noise-induced hearing loss. Hear Res. 2019; 379:59-68.