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Smith-Cortinez N, Tan AK, Stokroos RJ, Versnel H, Straatman LV. Regeneration of Hair Cells from Endogenous Otic Progenitors in the Adult Mammalian Cochlea: Understanding Its Origins and Future Directions. Int J Mol Sci 2023; 24:ijms24097840. [PMID: 37175547 PMCID: PMC10177935 DOI: 10.3390/ijms24097840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Sensorineural hearing loss is caused by damage to sensory hair cells and/or spiral ganglion neurons. In non-mammalian species, hair cell regeneration after damage is observed, even in adulthood. Although the neonatal mammalian cochlea carries regenerative potential, the adult cochlea cannot regenerate lost hair cells. The survival of supporting cells with regenerative potential after cochlear trauma in adults is promising for promoting hair cell regeneration through therapeutic approaches. Targeting these cells by manipulating key signaling pathways that control mammalian cochlear development and non-mammalian hair cell regeneration could lead to regeneration of hair cells in the mammalian cochlea. This review discusses the pathways involved in the development of the cochlea and the impact that trauma has on the regenerative capacity of the endogenous progenitor cells. Furthermore, it discusses the effects of manipulating key signaling pathways targeting supporting cells with progenitor potential to promote hair cell regeneration and translates these findings to the human situation. To improve hearing recovery after hearing loss in adults, we propose a combined approach targeting (1) the endogenous progenitor cells by manipulating signaling pathways (Wnt, Notch, Shh, FGF and BMP/TGFβ signaling pathways), (2) by manipulating epigenetic control, and (3) by applying neurotrophic treatments to promote reinnervation.
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Affiliation(s)
- Natalia Smith-Cortinez
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - A Katherine Tan
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Robert J Stokroos
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Louise V Straatman
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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The N-Methyl-D-Aspartate Receptor Blocker REL-1017 (Esmethadone) Reduces Calcium Influx Induced by Glutamate, Quinolinic Acid, and Gentamicin. Pharmaceuticals (Basel) 2022; 15:ph15070882. [PMID: 35890179 PMCID: PMC9319291 DOI: 10.3390/ph15070882] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 02/05/2023] Open
Abstract
REL-1017 (esmethadone) is a novel N-methyl-D-aspartate receptor (NMDAR) antagonist and promising rapid antidepressant candidate. Using fluorometric imaging plate reader (FLIPR) assays, we studied the effects of quinolinic acid (QA) and gentamicin, with or without L-glutamate and REL-1017, on intracellular calcium ([Ca2+]in) in recombinant cell lines expressing human GluN1-GluN2A, GluN1-GluN2B, GluN1-GluN2C, and GluN1-GluN2D NMDAR subtypes. There were no effects of QA on [Ca2+]in in cells expressing GluN1-GluN2C subtypes. QA acted as a low-potency, subtype-selective, NMDAR partial agonist in GluN1-GluN2A, GluN1-GluN2B, and GluN1-GluN2D subtypes. REL-1017 reduced [Ca2+]in induced by QA. In cells expressing the GluN1-GluN2D subtype, QA acted as an agonist in the presence of 0.04 μM L-glutamate and as an antagonist in the presence of 0.2 μM L-glutamate. REL-1017 reduced [Ca2+]in induced by L-glutamate alone and with QA in all cell lines. In the absence of L-glutamate, gentamicin had no effect. Gentamicin was a positive modulator for GluN1-GluN2B subtypes at 10 μM L-glutamate, for GluN1-GluN2A at 0.2 μM L-glutamate, and for GluN1-GluN2A, GluN1-GluN2B, and GluN1-GluN2D at 0.04 μM L-glutamate. No significant changes were observed with GluN1-GluN2C NMDARs. REL-1017 reduced [Ca2+]in induced by the addition of L-glutamate in all NMDAR cell lines in the presence or absence of gentamicin. In conclusion, REL-1017 reduced [Ca2+]in induced by L-glutamate alone and when increased by QA and gentamicin. REL-1017 may protect cells from excessive calcium entry via NMDARs hyperactivated by endogenous and exogenous molecules.
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Fu X, Wan P, Li P, Wang J, Guo S, Zhang Y, An Y, Ye C, Liu Z, Gao J, Yang J, Fan J, Chai R. Mechanism and Prevention of Ototoxicity Induced by Aminoglycosides. Front Cell Neurosci 2021; 15:692762. [PMID: 34211374 PMCID: PMC8239227 DOI: 10.3389/fncel.2021.692762] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/20/2021] [Indexed: 02/02/2023] Open
Abstract
Aminoglycosides, a class of clinically important drugs, are widely used worldwide against gram-negative bacterial infections. However, there is growing evidence that aminoglycosides can cause hearing loss or balance problems. In this article, we mainly introduce the main mechanism of ototoxicity induced by aminoglycosides. Genetic analysis showed that the susceptibility of aminoglycosides was attributable to mutations in mtDNA, especially A1555G and C1494T mutations in 12S rRNA. In addition, the overexpression of NMDA receptors and the formation of free radicals also play an important role. Understanding the mechanism of ototoxicity induced by aminoglycosides is helpful to develop new therapeutic methods to protect hearing. In this article, the prevention methods of ototoxicity induced by aminoglycosides were introduced from the upstream and downstream aspects.
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Affiliation(s)
- Xiaolong Fu
- State Key Laboratory of Bioelectronics, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China
| | - Peifeng Wan
- School of Life Science, Shandong University, Qingdao, China
| | - Peipei Li
- Department of Otology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jinpeng Wang
- The Key Laboratory of Animal Resistant Biology of Shandong, College of Life Science, Shandong Normal University, Jinan, China
| | - Siwei Guo
- School of Life Science, Shandong University, Qingdao, China
| | - Yuan Zhang
- Department of Otology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yachun An
- School of Life Science, Shandong University, Qingdao, China
| | - Chao Ye
- School of Life Science, Shandong University, Qingdao, China
| | - Ziyi Liu
- School of Life Science, Shandong University, Qingdao, China
| | - Jiangang Gao
- School of Life Science, Shandong University, Qingdao, China
| | - Jianming Yang
- Second Hospital of Anhui Medical University, Hefei, China
| | - Jiangang Fan
- Department of Otolaryngology Head and Neck Surgery, Sichuan Academy of Medical Science, Sichuan Provincial People's Hospital, Chengdu, China
| | - Renjie Chai
- State Key Laboratory of Bioelectronics, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.,Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, China
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Kim HJ, Lee JO, Kim JS. Protective Effects of Deferoxamine on Vestibulotoxicity in Gentamicin-Induced Bilateral Vestibulopathy Rat Model. Front Neurol 2021; 12:650752. [PMID: 33841317 PMCID: PMC8024619 DOI: 10.3389/fneur.2021.650752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/15/2021] [Indexed: 12/28/2022] Open
Abstract
Introduction: Administration of aminoglycoside (AG) antibiotics is one of the most common causes of ototoxicity. This study aimed to determine the protective effects of deferoxamine, an iron-chelating agent, on vestibulotoxicity using an intratympanic gentamicin injection (ITGM)-induced bilateral vestibulopathy rat model. Methods: Fifteen Sprague-Dawley rats were randomly assigned to the ITGM only (n = 5), the ITGM combined with intramuscular deferoxamine (DFO) injection (ITGM+DFO, n = 5), or the intratympanic normal saline (control, n = 5) group. The rats in the ITGM+DFO group received intramuscular injection of 150 mg/kg of deferoxamine at 30, 90, and 150 min after the ITGM. The vestibular function was evaluated using the rotarod and open field test every 3 days after the injection until Day 16 when the rats were subjected to histological changes. Results: The rats in the ITGM only group began to show significantly impaired vestibular function 2 days after ITGM into both ears. In contrast, the vestibular function was maintained in the control and ITGM+DFO groups without a difference throughout the experiments. The rats in the ITGM only group showed a near-complete loss of the type I and II hair cells and a collapse of the sensory epithelium in both the saccule and utricle. In contrast, the rats in the ITGM+DFO and control groups showed a relatively well-preserved sensory epithelium including the hair cells, cilia, and otolith layer. Conclusion: This study provides experimental evidence for preventive effects of iron-chelating agents on AG-induced vestibulotoxicity. Simultaneous administration of iron-chelating agents may be considered when using ototoxic agents, especially in those considered to be vulnerable to toxic damage of the inner ear.
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Affiliation(s)
- Hyo-Jung Kim
- Research Administration Team, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Jin-Ok Lee
- Department of Biomedicine and Health Sciences, Graduate School, The Catholic University of Korea, Seoul, South Korea
| | - Ji-Soo Kim
- Department of Neurology, Seoul National University College of Medicine, Seoul, South Korea.,Department of Neurology, Dizziness Center, Clinical Neuroscience Center, Seoul National University Bundang Hospital, Seongnam, South Korea
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Sargsyan L, Hetrick AP, Gonzalez JG, Leek MR, Martin GK, Li H. Effects of combined gentamicin and furosemide treatment on cochlear ribbon synapses. Neurotoxicology 2021; 84:73-83. [PMID: 33667563 DOI: 10.1016/j.neuro.2021.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 12/29/2022]
Abstract
It is well-established that aminoglycoside antibiotics are ototoxic, and the toxicity can be drastically enhanced by the addition of loop diuretics, resulting in rapid irreversible hair cell damage. Using both electrophysiologic and morphological approaches, we investigated whether this combined treatment affected the cochlea at the region of ribbon synapses, consequently resulting in auditory synaptopathy. A series of varied gentamicin and furosemide doses were applied to C57BL/6 mice, and auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE) were measured to assess ototoxic damage within the cochlea. In brief, the treatment effectively induced cochlear damage and promoted a certain reorganization of synaptic ribbons, while a reduction of ribbon density only occurred after a substantial loss of outer hair cells. In addition, both the ABR wave I amplitude and the ribbon density were elevated in low-dose treatment conditions, but a correlation between the two events was not significant for individual cochleae. In sum, combined gentamicin and furosemide treatment, at titrated doses below those that produce hair cell damage, typically triggers synaptic plasticity rather than a permanent synaptic loss.
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Affiliation(s)
- Liana Sargsyan
- Research Service, VA Loma Linda Healthcare System, CA 92357, USA
| | - Alisa P Hetrick
- Research Service, VA Loma Linda Healthcare System, CA 92357, USA
| | | | - Marjorie R Leek
- Research Service, VA Loma Linda Healthcare System, CA 92357, USA; Department of Otolaryngology - Head and Neck Surgery, Loma Linda University Health, Loma Linda, CA 92354, USA
| | - Glen K Martin
- Research Service, VA Loma Linda Healthcare System, CA 92357, USA; Department of Otolaryngology - Head and Neck Surgery, Loma Linda University Health, Loma Linda, CA 92354, USA
| | - Hongzhe Li
- Research Service, VA Loma Linda Healthcare System, CA 92357, USA; Department of Otolaryngology - Head and Neck Surgery, Loma Linda University Health, Loma Linda, CA 92354, USA.
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Greguske EA, Llorens J, Pyott SJ. Assessment of cochlear toxicity in response to chronic 3,3'-iminodipropionitrile in mice reveals early and reversible functional loss that precedes overt histopathology. Arch Toxicol 2021; 95:1003-1021. [PMID: 33495873 PMCID: PMC7904549 DOI: 10.1007/s00204-020-02962-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/26/2020] [Indexed: 12/19/2022]
Abstract
The peripheral auditory and vestibular systems rely on sensorineural structures that are vulnerable to ototoxic agents that cause hearing loss and/or equilibrium deficits. Although attention has focused on hair cell loss as the primary pathology underlying ototoxicity, evidence from the peripheral vestibular system indicates that hair cell loss during chronic exposure is preceded by synaptic uncoupling from the neurons and is potentially reversible. To determine if synaptic pathology also occurs in the peripheral auditory system, we examined the extent, time course, and reversibility of functional and morphological alterations in cochleae from mice exposed to 3,3′-iminodipropionitrile (IDPN) in drinking water for 2, 4 or 6 weeks. Functionally, IDPN exposure caused progressive high- to low-frequency hearing loss assessed by measurement of auditory brainstem response wave I absolute thresholds and amplitudes. The extent of hearing loss scaled with the magnitude of vestibular dysfunction assessed behaviorally. Morphologically, IDPN exposure caused progressive loss of outer hair cells (OHCs) and synapses between the inner hair cells (IHCs) and primary auditory neurons. In contrast, IHCs were spared from ototoxic damage. Importantly, hearing loss consistent with cochlear synaptopathy preceded loss of OHCs and synapses and, moreover, recovered if IDPN exposure was stopped before morphological pathology occurred. Our observations suggest that synaptic uncoupling, perhaps as an early phase of cochlear synaptopathy, also occurs in the peripheral auditory system in response to IDPN exposure. These findings identify novel mechanisms that contribute to the earliest stages of hearing loss in response to ototoxic agents and possibly other forms of acquired hearing loss.
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Affiliation(s)
- Erin A Greguske
- Departament de Ciències Fisiològiques and Institut de Neurociències, Universitat de Barcelona, 08907, L'Hospitalet de Llobregat, Catalonia, Spain.,Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907, L'Hospitalet de Llobregat, Catalonia, Spain
| | - Jordi Llorens
- Departament de Ciències Fisiològiques and Institut de Neurociències, Universitat de Barcelona, 08907, L'Hospitalet de Llobregat, Catalonia, Spain.,Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907, L'Hospitalet de Llobregat, Catalonia, Spain
| | - Sonja J Pyott
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, The Netherlands.
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Chen HC, Wang CH, Chien WC, Chung CH, Shih CP, Lin YC, Li IH, Lin YY, Kuo CY. Dextromethorphan Attenuates Sensorineural Hearing Loss in an Animal Model and Population-Based Cohort Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17176336. [PMID: 32878128 PMCID: PMC7504445 DOI: 10.3390/ijerph17176336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 12/24/2022]
Abstract
The effect of dextromethorphan (DXM) use in sensorineural hearing loss (SNHL) has not been fully examined. We conducted an animal model and nationwide retrospective matched-cohort study to explore the association between DXM use and SNHL. Eight-week-old CBA/CaJ hearing loss was induced by a white noise 118 dB sound pressure level for 3 h. DXM (30 mg/kg) was administered intraperitoneally for 5 days and boost once round window DXM socking. In population-based study, we examined the medical records over 40 years old in Taiwan’s National Health Insurance Research Database between 2000 and 2015 to establish retrospective matched-cohort to explore the correlation between DXM use and SNHL. Using click auditory brainstem response (ABR), hearing threshold was measured as 48.6 ± 2.9 dB in control mice compared with 42.6 ± 7.0 dB in DXM mice, which differed significantly (p = 0.002) on day 60 after noise exposure with a larger ABR wave I amplitude in DXM mice. In human study, we used a Cox regression hazard model to indicate that a significantly lower percentage individuals developed SNHL compared with and without DXM use (0.44%, 175/39,895 vs. 1.05%, 1675/159,580, p < 0.001). After adjustment for age and other variables [adjusted hazard ratio: 0.725 (95% confidence interval: 0.624–0.803, p < 0.001)], this study also demonstrated that DXM use appeared to reduce the risk of developing SNHL. This animal study demonstrated that DXM significantly attenuated noise-induced hearing loss. In human study, DXM use may have a protective effect against SNHL.
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Affiliation(s)
- Hsin-Chien Chen
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (C.-H.W.); (C.-P.S.); (Y.-C.L.); (Y.-Y.L.); (C.-Y.K.)
- Correspondence: ; Tel.: +886-2-8792-7192; Fax: +886-2-8792-7193
| | - Chih-Hung Wang
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (C.-H.W.); (C.-P.S.); (Y.-C.L.); (Y.-Y.L.); (C.-Y.K.)
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei 114, Taiwan
| | - Wu-Chien Chien
- School of Public Health, National Defense Medical Center, Taipei 114, Taiwan; (W.-C.C.); (C.-H.C.)
- Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Chi-Hsiang Chung
- School of Public Health, National Defense Medical Center, Taipei 114, Taiwan; (W.-C.C.); (C.-H.C.)
- Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Cheng-Ping Shih
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (C.-H.W.); (C.-P.S.); (Y.-C.L.); (Y.-Y.L.); (C.-Y.K.)
| | - Yi-Chun Lin
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (C.-H.W.); (C.-P.S.); (Y.-C.L.); (Y.-Y.L.); (C.-Y.K.)
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei 114, Taiwan
| | - I-Hsun Li
- Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan;
- School of Pharmacy, National Defense Medical Center, Taipei 114, Taiwan
| | - Yuan-Yung Lin
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (C.-H.W.); (C.-P.S.); (Y.-C.L.); (Y.-Y.L.); (C.-Y.K.)
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei 114, Taiwan
| | - Chao-Yin Kuo
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (C.-H.W.); (C.-P.S.); (Y.-C.L.); (Y.-Y.L.); (C.-Y.K.)
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Glutamate-Gated NMDA Receptors: Insights into the Function and Signaling in the Kidney. Biomolecules 2020; 10:biom10071051. [PMID: 32679780 PMCID: PMC7407907 DOI: 10.3390/biom10071051] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 12/21/2022] Open
Abstract
N-Methyl-d-aspartate receptor (NMDAR) is a glutamate-gated ionotropic receptor that intervenes in most of the excitatory synaptic transmission within the central nervous system (CNS). Aside from being broadly distributed in the CNS and having indispensable functions in the brain, NMDAR has predominant roles in many physiological and pathological processes in a wide range of non-neuronal cells and tissues. The present review outlines current knowledge and understanding of the physiological and pathophysiological functions of NMDAR in the kidney, an essential excretory and endocrine organ responsible for the whole-body homeostasis. The review also explores the recent findings regarding signaling pathways involved in NMDAR-mediated responses in the kidney. As established from diverse lines of research reviewed here, basal levels of receptor activation within the kidney are essential for the maintenance of healthy tubular and glomerular function, while a disproportionate activation can lead to a disruption of NMDAR's downstream signaling pathways and a myriad of pathophysiological consequences.
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The Novel Peptide Vaccine GV1001 Protects Hearing in a Kanamycin-induced Ototoxicity Mouse Model. Otol Neurotol 2019; 39:e731-e737. [PMID: 30015752 DOI: 10.1097/mao.0000000000001911] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
HYPOTHESIS We tested whether GV1001 has any ototoxic side effects at different doses and whether it protects hearing in an aminoglycoside-induced ototoxicity mouse model. BACKGROUND GV1001, a novel peptide vaccine currently being examined in a Phase 3 clinical trial to treat pancreatic cancer, also has anti-inflammatory and antioxidant effects. METHODS In the first experiment, C57/BL6 mice were injected with GV1001 preparations at concentrations of 0.1 to 100 mg/kg for 7 days to evaluate the toxicity of GV1001 on the inner ear and kidneys. In the second experiment, the protective effect of GV1001 was tested in an ototoxicity mouse model that was generated by injecting 800 mg/kg kanamycin (KM) for 2 weeks. The hearing threshold and hair cell loss were compared between the KM + GV1001 group (treated with 10 mg/kg GV1001 for 2 wk) and the KM + saline group. The hearing threshold was measured before, and 7, 14, and 21 days after the initial treatment. The blood urea nitrogen level was measured. RESULTS No ototoxicity or renal toxicity was found following treatment with different doses of GV1001 (0.1-100 mg/kg). The KM + saline group showed impaired auditory function and markedly disoriented and missing cochlear hair cells, while the KM + GV1001 group showed significant hearing and hair cell preservation in comparison (p < 0.05). CONCLUSION GV1001 itself did not have any detrimental effects on the inner ear or kidney. In the KM induced ototoxicity model, concomitant administration of GV1001 protected against cochlear hair cell damage and preserve hearing.
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Kaufman AC, Eliades SJ. Vestibulotoxicity in a patient without renal failure after inhaled tobramycin. Am J Otolaryngol 2019; 40:456-458. [PMID: 30910434 DOI: 10.1016/j.amjoto.2019.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 03/19/2019] [Indexed: 10/27/2022]
Abstract
Aminoglycoside antibiotics have a long history of use in the control of gram-negative bacterial infections, but their systemic use has been complicated by known ototoxicity and nephrotoxicity. Because of the utility of these medications in patients with frequent pulmonary infections, there has been a move towards the use of inhaled agents, in particular tobramycin, due to a lower rate of systemic complications. Inhaled tobramycin is generally consider to be safe from otologic complications, with only two previous reports of ototoxicity, both in patients who had underlying chronic renal disease. Here we present the first case of a patient developing isolated vestibular toxicity, without associated hearing loss or evidence of renal insufficiency, in a patient receiving inhaled tobramycin. This is an extremely rare complication of an inhaled aminoglycoside and underscores the importance of careful monitoring despite perceived safety.
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Hong H, Dooley KE, Starbird LE, Francis HW, Farley JE. Adverse outcome pathway for aminoglycoside ototoxicity in drug-resistant tuberculosis treatment. Arch Toxicol 2019; 93:1385-1399. [PMID: 30963202 DOI: 10.1007/s00204-019-02407-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/06/2019] [Indexed: 12/22/2022]
Abstract
Individuals treated for multidrug-resistant tuberculosis (MDR-TB) with aminoglycosides (AGs) in resource-limited settings often experience permanent hearing loss. However, AG ototoxicity has never been conceptually integrated or causally linked to MDR-TB patients' pre-treatment health condition. We sought to develop a framework that examines the relationships between pre-treatment conditions and AG-induced hearing loss among MDR-TB-infected individuals in sub-Saharan Africa. The adverse outcome pathway (AOP) approach was used to develop a framework linking key events (KEs) within a biological pathway that results in adverse outcomes (AO), which are associated with chemical perturbation of a molecular initiating event (MIE). This AOP describes pathways initiating from AG accumulation in hair cells, sound transducers of the inner ear immediately after AG administration. After administration, the drug catalyzes cellular oxidative stress due to overproduction of reactive oxygen species. Since oxidative stress inhibits mitochondrial protein synthesis, hair cells undergo apoptotic cell death, resulting in irreversible hearing loss (AO). We identified the following pre-treatment conditions that worsen the causal linkage between MIE and AO: HIV, malnutrition, aging, noise, smoking, and alcohol use. The KEs are: (1) nephrotoxicity, pre-existing hearing loss, and hypoalbuminemia that catalyzes AG accumulation; (2) immunodeficiency and antioxidant deficiency that trigger oxidative stress pathways; and (3) co-administration of mitochondrial toxic drugs that hinder mitochondrial protein synthesis, causing apoptosis. This AOP clearly warrants the development of personalized interventions for patients undergoing MDR-TB treatment. Such interventions (i.e., choosing less ototoxic drugs, scheduling frequent monitoring, modifying nutritional status, avoiding poly-pharmacy) will be required to limit the burden of AG ototoxicity.
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Affiliation(s)
- Hyejeong Hong
- Johns Hopkins University School of Nursing, 525 North Wolfe Street, Baltimore, MD, 21205, USA. .,Johns Hopkins University School of Nursing, The REACH Initiative, 855 N. Wolfe Street, 21205, Baltimore, MD, USA.
| | - Kelly E Dooley
- Divisions of Clinical Pharmacology and Infectious Disease, Johns Hopkins University School of Medicine, 600 North Wolfe Street, 21205, Baltimore, MD, USA
| | - Laura E Starbird
- Center for Health Policy, Columbia University School of Nursing, 560 W 168 St, 10032, New York, NY, USA
| | - Howard W Francis
- Division of Head and Neck Surgery and Communication Sciences, Duke University School of Medicine, 40 Duke Medicine Circle, 27710, Durham, NC, USA
| | - Jason E Farley
- Johns Hopkins University School of Nursing, 525 North Wolfe Street, Baltimore, MD, 21205, USA.,Johns Hopkins University School of Nursing, The REACH Initiative, 855 N. Wolfe Street, 21205, Baltimore, MD, USA
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Second-line injectable induced ototoxicity in drug resistant tuberculosis: A systematic review of Indian studies. ACTA ACUST UNITED AC 2019; 66:279-287. [DOI: 10.1016/j.ijtb.2019.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/04/2019] [Accepted: 04/04/2019] [Indexed: 11/20/2022]
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N-Methyl-D-Aspartate Receptors Involvement in the Gentamicin-Induced Hearing Loss and Pathological Changes of Ribbon Synapse in the Mouse Cochlear Inner Hair Cells. Neural Plast 2018; 2018:3989201. [PMID: 30123246 PMCID: PMC6079453 DOI: 10.1155/2018/3989201] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 05/17/2018] [Indexed: 11/17/2022] Open
Abstract
Cochlear inner hair cell (IHC) ribbon synapses play an important role in sound encoding and neurotransmitter release. Previous reports show that both noise and aminoglycoside exposures lead to reduced numbers and morphologic changes of synaptic ribbons. In this work, we determined the distribution of N-methyl-D-aspartate receptors (NMDARs) and their role in the gentamicin-induced pathological changes of cochlear IHC ribbon synaptic elements. In normal mature mouse cochleae, the majority of NMDARs were distributed on the modiolar side of IHCs and close to the IHC nuclei region, while most of synaptic ribbons and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) were located on neural terminals closer to the IHC basal poles. After gentamicin exposure, the NMDARs increased and moved towards the IHC basal poles. At the same time, synaptic ribbons and AMPARs moved toward the IHC bundle poles on the afferent dendrites. The number of ribbon synapse decreased, and this was accompanied by increased auditory brainstem response thresholds and reduced wave I amplitudes. NMDAR antagonist MK801 treatment reduced the gentamicin-induced hearing loss and the pathological changes of IHC ribbon synapse, suggesting that NMDARs were involved in gentamicin-induced ototoxicity by regulating the number and distribution of IHC ribbon synapses.
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Saxena A. Ototoxicity from the Aminoglycoside-Heparin/Citrate Locks Applied for the Prevention of Hemodialysis Catheter-Related Infections. J Vasc Access 2018. [DOI: 10.1177/112972980300400108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- A.K. Saxena
- Nephrology Division, Post-graduate Department of Medicine King Fahad Hospital and Tertiary Care Center, Hofuf - Saudi Arabia
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Kenyon EJ, Kirkwood NK, Kitcher SR, O'Reilly M, Derudas M, Cantillon DM, Goodyear RJ, Secker A, Baxendale S, Bull JC, Waddell SJ, Whitfield TT, Ward SE, Kros CJ, Richardson GP. Identification of ion-channel modulators that protect against aminoglycoside-induced hair cell death. JCI Insight 2017; 2:96773. [PMID: 29263311 DOI: 10.1172/jci.insight.96773] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/15/2017] [Indexed: 12/22/2022] Open
Abstract
Aminoglycoside antibiotics are used to treat life-threatening bacterial infections but can cause deafness due to hair cell death in the inner ear. Compounds have been described that protect zebrafish lateral line hair cells from aminoglycosides, but few are effective in the cochlea. As the aminoglycosides interact with several ion channels, including the mechanoelectrical transducer (MET) channels by which they can enter hair cells, we screened 160 ion-channel modulators, seeking compounds that protect cochlear outer hair cells (OHCs) from aminoglycoside-induced death in vitro. Using zebrafish, 72 compounds were identified that either reduced loading of the MET-channel blocker FM 1-43FX, decreased Texas red-conjugated neomycin labeling, or reduced neomycin-induced hair cell death. After testing these 72 compounds, and 6 structurally similar compounds that failed in zebrafish, 13 were found that protected against gentamicin-induced death of OHCs in mouse cochlear cultures, 6 of which are permeant blockers of the hair cell MET channel. None of these compounds abrogated aminoglycoside antibacterial efficacy. By selecting those without adverse effects at high concentrations, 5 emerged as leads for developing pharmaceutical otoprotectants to alleviate an increasing clinical problem.
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Affiliation(s)
| | | | | | | | - Marco Derudas
- Sussex Drug Discovery Centre, School of Life Sciences, and
| | - Daire M Cantillon
- Wellcome Trust Centre for Global Health Research, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | | | | | - Sarah Baxendale
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - James C Bull
- Department of Biosciences, College of Science, Swansea University, Swansea, United Kingdom
| | - Simon J Waddell
- Wellcome Trust Centre for Global Health Research, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | - Tanya T Whitfield
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Simon E Ward
- Sussex Drug Discovery Centre, School of Life Sciences, and.,Medicines Discovery Institute, Cardiff University, Cardiff, United Kingdom
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Ding D, Jiang H, Chen GD, Longo-Guess C, Muthaiah VPK, Tian C, Sheppard A, Salvi R, Johnson KR. N-acetyl-cysteine prevents age-related hearing loss and the progressive loss of inner hair cells in γ-glutamyl transferase 1 deficient mice. Aging (Albany NY) 2017; 8:730-50. [PMID: 26977590 PMCID: PMC4925825 DOI: 10.18632/aging.100927] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 02/18/2016] [Indexed: 02/07/2023]
Abstract
Genetic factors combined with oxidative stress are major determinants of age-related hearing loss (ARHL), one of the most prevalent disorders of the elderly. Dwarf grey mice, Ggt1dwg/dwg, are homozygous for a loss of function mutation of the γ-glutamyl transferase 1 gene, which encodes an important antioxidant enzyme critical for the resynthesis of glutathione (GSH). Since GSH reduces oxidative damage, we hypothesized that Ggt1dwg/dwg mice would be susceptible to ARHL. Surprisingly, otoacoustic emissions and cochlear microphonic potentials, which reflect cochlear outer hair cell (OHC) function, were largely unaffected in mutant mice, whereas auditory brainstem responses and the compound action potential were grossly abnormal. These functional deficits were associated with an unusual and selective loss of inner hair cells (IHC), but retention of OHC and auditory nerve fibers. Remarkably, hearing deficits and IHC loss were completely prevented by N-acetyl-L-cysteine, which induces de novo synthesis of GSH; however, hearing deficits and IHC loss reappeared when treatment was discontinued. Ggt1dwg/dwgmice represent an important new model for investigating ARHL, therapeutic interventions, and understanding the perceptual and electrophysiological consequences of sensory deprivation caused by the loss of sensory input exclusively from IHC.
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Affiliation(s)
- Dalian Ding
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
| | - Haiyan Jiang
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
| | | | | | - Cong Tian
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Adam Sheppard
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
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Cortada M, Levano S, Bodmer D. Brimonidine Protects Auditory Hair Cells from in vitro-Induced Toxicity of Gentamicin. Audiol Neurootol 2017; 22:125-134. [PMID: 28889125 DOI: 10.1159/000479218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 07/05/2017] [Indexed: 12/11/2022] Open
Abstract
Brimonidine, an alpha-2 adrenergic receptor (α2-AR) agonist, has neuroprotective effects in the visual system and in spiral ganglion neurons. Auditory hair cells (HCs) express all 3 α2-AR subtypes, but their roles in HCs remain unknown. This study investigated the effects of brimonidine on auditory HCs that were also exposed to gentamicin, which is toxic to HCs. Organ of Corti explants were exposed to gentamicin in the presence or absence of brimonidine, and the α2-AR protein expression levels and Erk1/2 and Akt phosphorylation levels were determined. Brimonidine had a protective effect on auditory HCs against gentamicin-induced toxicity that was blocked by yohimbine. This suggested that the protective effect of brimonidine on HCs was mediated by the α2-AR. None of the treatments altered α2-AR protein expression levels, and brimonidine did not significantly change the activation levels of the Erk1/2 and Akt proteins. These observations indicated that brimonidine, acting directly via α2-AR, protects HCs from gentamicin-induced toxicity. Therefore, brimonidine shows potential for preventing or treating sensorineural hearing loss.
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Affiliation(s)
- Maurizio Cortada
- Department of Biomedicine, University of Basel, Basel, Switzerland
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Cochlear synaptopathy in acquired sensorineural hearing loss: Manifestations and mechanisms. Hear Res 2017; 349:138-147. [PMID: 28087419 DOI: 10.1016/j.heares.2017.01.003] [Citation(s) in RCA: 406] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 12/19/2016] [Accepted: 01/05/2017] [Indexed: 12/20/2022]
Abstract
Common causes of hearing loss in humans - exposure to loud noise or ototoxic drugs and aging - often damage sensory hair cells, reflected as elevated thresholds on the clinical audiogram. Recent studies in animal models suggest, however, that well before this overt hearing loss can be seen, a more insidious, but likely more common, process is taking place that permanently interrupts synaptic communication between sensory inner hair cells and subsets of cochlear nerve fibers. The silencing of affected neurons alters auditory information processing, whether accompanied by threshold elevations or not, and is a likely contributor to a variety of perceptual abnormalities, including speech-in-noise difficulties, tinnitus and hyperacusis. Work described here will review structural and functional manifestations of this cochlear synaptopathy and will consider possible mechanisms underlying its appearance and progression in ears with and without traditional 'hearing loss' arising from several common causes in humans.
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Kim BY, Bae WY, Hur DY, Kim JR, Koh TK, Lee TH, Park GB. Effects of Memantine on Aminoglycoside-Induced Apoptosis of Spiral Ganglion Cells in Guinea Pigs. Otolaryngol Head Neck Surg 2016; 155:147-54. [DOI: 10.1177/0194599816639297] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 02/25/2016] [Indexed: 12/20/2022]
Abstract
Objective To explore whether memantine, an N-methyl-D-aspartate receptor antagonist, exerts a neuroprotective effect against apoptosis of spiral ganglion cells (SGCs) induced by gentamicin. Study Design An animal experiment. Setting Dong-A University College of Medicine, Busan, Korea. Subjects and Methods Gentamicin was injected into the left cochleae of guinea pigs to induce apoptosis of SGCs; the contralateral cochleae served as controls. Memantine was intraperitoneally injected 12 hours and 1 hour prior to gentamicin injection. At 1 week after gentamicin and/or memantine injection, the cochleae were removed and stained with hematoxylin and eosin to evaluate morphologic changes and apoptosis. Western blotting was performed to measure FasL expression and the extent of caspase activation in SGCs. Results SGC numbers remained stable after memantine treatment. Western blotting showed that FasL expression and activation of caspases 3, 8, and 9 were reduced in SGCs after memantine treatment. Conclusion Memantine attenuated the gentamicin-induced apoptosis of SGCs in guinea pigs. Moreover, memantine may affect Fas-FasL signaling in the receptor-mediated apoptotic pathway and caspase activation involved in the receptor-mediated and mitochondrial apoptotic pathways.
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Affiliation(s)
- Bo Young Kim
- Department of Department of Otolaryngology–Head and Neck Surgery, Marynol Hospital, Busan, Korea
| | - Woo Yong Bae
- Department of Otolaryngology–Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea
| | - Dae Young Hur
- Department of Anatomy and Tumor Immunology, Inje University College of Medicine, Busan, Korea
| | - Jae-Ryong Kim
- Department of Otolaryngology–Head and Neck Surgery, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Tae Kyung Koh
- Department of Otolaryngology–Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea
| | - Tae Hoon Lee
- Department of Otolaryngology–Head and Neck Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Ga Bin Park
- Department of Anatomy and Tumor Immunology, Inje University College of Medicine, Busan, Korea
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Abstract
INTRODUCTION NMDA receptor (NMDAR) is an ionotropic glutamate receptor with a high permeability to calcium and a unique feature of controlling numerous calcium-dependent processes. Apart from being widely distributed in the CNS, the presence of NMDAR and its potential significance in a variety of non-neuronal cells and tissues has become an interesting research topic. AREAS COVERED The current review summarizes prevailing knowledge on the role of NMDARs in the kidney, bone and parathyroid gland, three main organs responsible for calcium homeostasis, as well as in the heart, an organ whose function is highly dependable on balanced intracellular calcium concentrations. The review also examines studies that have advanced our understanding of the therapeutic potential of NMDAR agonists and antagonists in renal, cardiovascular and bone pathologies. EXPERT OPINION NMDARs have a preeminent role in many physiological and pathological processes outside the CNS. In certain organs and/or disease conditions, activating the NMDAR leads to beneficial effects for the target organ, whereas in other diseases cell signaling downstream of NMDAR activation can exacerbate their pathology. Therefore, targeting NMDARs therapeutically is rather intricate work, and surely requires more extensive investigation in order to properly tune up the diverse NMDAR's actions translating them into beneficial cellular responses.
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Affiliation(s)
- Milica Bozic
- Institute for Biomedical Research (IRB Lleida), Nephrology Research Department , Edificio Biomedicina 1. Lab B1-10, Lleida , Spain +34 973 003 650 ; +34 973 702 213 ;
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22
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Cederroth CR, Canlon B, Langguth B. Hearing loss and tinnitus--are funders and industry listening? Nat Biotechnol 2014; 31:972-4. [PMID: 24213768 DOI: 10.1038/nbt.2736] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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23
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Figueroa VA, Retamal MA, Cea LA, Salas JD, Vargas AA, Verdugo CA, Jara O, Martínez AD, Sáez JC. Extracellular gentamicin reduces the activity of connexin hemichannels and interferes with purinergic Ca(2+) signaling in HeLa cells. Front Cell Neurosci 2014; 8:265. [PMID: 25237294 PMCID: PMC4154469 DOI: 10.3389/fncel.2014.00265] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 08/18/2014] [Indexed: 01/15/2023] Open
Abstract
Gap junction channels (GJCs) and hemichannels (HCs) are composed of protein subunits termed connexins (Cxs) and are permeable to ions and small molecules. In most organs, GJCs communicate the cytoplasm of adjacent cells, while HCs communicate the intra and extracellular compartments. In this way, both channel types coordinate physiological responses of cell communities. Cx mutations explain several genetic diseases, including about 50% of autosomal recessive non-syndromic hearing loss. However, the possible involvement of Cxs in the etiology of acquired hearing loss remains virtually unknown. Factors that induce post-lingual hearing loss are diverse, exposure to gentamicin an aminoglycoside antibiotic, being the most common. Gentamicin has been proposed to block GJCs, but its effect on HCs remains unknown. In this work, the effect of gentamicin on the functional state of HCs was studied and its effect on GJCs was reevaluated in HeLa cells stably transfected with Cxs. We focused on Cx26 because it is the main Cx expressed in the cochlea of mammals where it participates in purinergic signaling pathways. We found that gentamicin applied extracellularly reduces the activity of HCs, while dye transfer across GJCs was not affected. HCs were also blocked by streptomycin, another aminoglycoside antibiotic. Gentamicin also reduced the adenosine triphosphate release and the HC-dependent oscillations of cytosolic free-Ca2+ signal. Moreover, gentamicin drastically reduced the Cx26 HC-mediated membrane currents in Xenopus laevis oocytes. Therefore, the extracellular gentamicin-induced inhibition of Cx HCs may adversely affect autocrine and paracrine signaling, including the purinergic one, which might partially explain its ototoxic effects.
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Affiliation(s)
- Vania A Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile ; Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo Santiago, Chile
| | - Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo Santiago, Chile
| | - Luis A Cea
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile
| | - José D Salas
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo Santiago, Chile
| | - Aníbal A Vargas
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile
| | - Christian A Verdugo
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo Santiago, Chile
| | - Oscar Jara
- Instituto Milenio, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
| | - Agustín D Martínez
- Instituto Milenio, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
| | - Juan C Sáez
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile ; Instituto Milenio, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
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Aksoy F, Dogan R, Ozturan O, Eren SB, Veyseller B, Pektas A, Hüseyinbas Ö. Protective effect of trimetazidine on amikacin-induced ototoxicity in rats. Int J Pediatr Otorhinolaryngol 2014; 78:663-9. [PMID: 24582075 DOI: 10.1016/j.ijporl.2014.01.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 01/20/2014] [Accepted: 01/22/2014] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Aminoglycoside antibiotics are known to have ototoxic effects and may induce sensorineural hearing loss. This study investigated the protective effect of trimetazidine, which has antioxidant and cytoprotective properties, against amikacin ototoxicity. METHODS Thirty-two male rats were divided into four groups - amikacin, amikacin + trimetazidine, trimetazidine, and control groups. Trimetazidine, 10 mg/kg per day, was given for 14 days by oral gavage. Amikacin, 600 mg/kg per day, was also given for 14 days, by the intramuscular route. Distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) tests were applied to the rats for hearing assessment. At the termination of the study, the biochemical parameters were calculated to evaluate the oxidative status. RESULTS The DPOAE values of the amikacin group were significantly lower on the 7th and 14th days than those of the trimetazidine + amikacin group and there was an increase in the ABR thresholds. The ABR thresholds for the amikacin group on the 7th and 14th days were significantly higher than the levels on the first day of the study, while there was no significant increase in those values in the trimetazidine + amikacin group. The total oxidant status (TOS) and oxidant status index (OSI) values of the amikacin group were significantly higher than those of the trimetazidine + amikacin group. The total antioxidant status (TAS) values of the amikacin group were lower than those of the trimetazidine + amikacin group. CONCLUSIONS The audiologic tests and biochemical parameters investigated in this study both point to the protective effect of trimetazidine against amikacin-induced ototoxicity.
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Affiliation(s)
- Fadlullah Aksoy
- Bezmialem Vakif University, Department of Otorhinolaryngology, Fatih, Istanbul, Turkey
| | - Remzi Dogan
- Bezmialem Vakif University, Department of Otorhinolaryngology, Fatih, Istanbul, Turkey.
| | - Orhan Ozturan
- Bezmialem Vakif University, Department of Otorhinolaryngology, Fatih, Istanbul, Turkey
| | - Sabri Baki Eren
- Bezmialem Vakif University, Department of Otorhinolaryngology, Fatih, Istanbul, Turkey
| | - Bayram Veyseller
- Bezmialem Vakif University, Department of Otorhinolaryngology, Fatih, Istanbul, Turkey
| | - Alev Pektas
- Bezmialem Vakif University, Faculty of Health Sciences, Department of Audiology, Fatih, Istanbul, Turkey
| | - Önder Hüseyinbas
- Bezmialem Vakif University, Research Center, Fatih, Istanbul, Turkey
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Effect of intratympanic dimethyl sulphoxide (DMSO) in an in vivo model of cisplatin-related ototoxicity. Eur Arch Otorhinolaryngol 2014; 271:3121-6. [DOI: 10.1007/s00405-014-2957-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 02/17/2014] [Indexed: 12/14/2022]
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Polony G, Humli V, Andó R, Aller M, Horváth T, Harnos A, Tamás L, Vizi ES, Zelles T. Protective effect of rasagiline in aminoglycoside ototoxicity. Neuroscience 2014; 265:263-73. [PMID: 24508748 DOI: 10.1016/j.neuroscience.2014.01.057] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/13/2014] [Accepted: 01/29/2014] [Indexed: 12/28/2022]
Abstract
Sensorineural hearing losses (SNHLs; e.g., ototoxicant- and noise-induced hearing loss or presbycusis) are among the most frequent sensory deficits, but they lack effective drug therapies. The majority of recent therapeutic approaches focused on the trials of antioxidants and reactive oxygen species (ROS) scavengers in SNHLs. The rationale for these studies was the prominent role of disturbed redox homeostasis and the consequent ROS elevation. Although the antioxidant therapies in several animal studies seemed to be promising, clinical trials have failed to fulfill expectations. We investigated the potential of rasagiline, an FDA-approved monomanine oxidase type B inhibitor (MAO-B) inhibitor type anti-parkinsonian drug, as an otoprotectant. We showed a dose-dependent alleviation of the kanamycin-induced threshold shifts measured by auditory brainstem response (ABR) in an ototoxicant aminoglycoside antibiotic-based hearing loss model in mice. This effect proved to be statistically significant at a 6-mg/kg (s.c.) dose. The most prominent effect appeared at 16kHz, which is the hearing sensitivity optimum for mice. The neuroprotective, antiapoptotic and antioxidant effects of rasagiline in animal models, all targeting a specific mechanism of aminoglycoside injury, may explain this otoprotection. The dopaminergic neurotransmission enhancer effect of rasagiline might also contribute to the protection. Dopamine (DA), released from lateral olivocochlear (LOC) fibers, was shown to exert a protective action against excitotoxicity, a pathological factor in the aminoglycoside-induced SNHL. We have shown that rasagiline enhanced the electric stimulation-evoked release of DA from an acute mouse cochlea preparation in a dose-dependent manner. Using inhibitors of voltage-gated Na(+)-, Ca(2+) channels and DA transporters, we revealed that rasagiline potentiated the action potential-evoked release of DA by inhibiting the reuptake. The complex, multifactorial pathomechanism of SNHLs most likely requires drugs acting on multiple targets for effective therapy. Rasagiline, with its multi-target action and favorable adverse effects profile, might be a good candidate for a clinical trial testing the otoprotective indication.
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Affiliation(s)
- G Polony
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Budapest, Hungary; Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - V Humli
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - R Andó
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Budapest, Hungary
| | - M Aller
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - T Horváth
- Department of Otorhinolaryngology, Bajcsy-Zsilinszky Hospital, Budapest, Hungary; Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - A Harnos
- Department of Biomathematics and Informatics, Szent István University, Budapest, Hungary
| | - L Tamás
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Budapest, Hungary
| | - E S Vizi
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary; Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - T Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary; Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
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Blakley BW, Alsaleh S, Dewji Z, Qureshy K, Berard S, Xie L. Steroids in aminoglycoside-containing ear drops: do they reduce cochlear toxicity? Laryngoscope 2013; 124:1209-13. [PMID: 24142776 DOI: 10.1002/lary.24475] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 09/07/2013] [Accepted: 10/15/2013] [Indexed: 11/10/2022]
Abstract
OBJECTIVES/HYPOTHESIS To determine whether betamethasone (BM) reduces the cochlear toxicity of otic gentamicin (GM) if given together. STUDY DESIGN Controlled animal study. METHODS Thirty-four mice were assigned at random to receive intratympanic injections of either 0.1 % BM (11 mice), 0.3% GM (13 mice), or a combination of both (GM/BM) with benzalkonium chloride (10 mice) in the left ear (treated) and saline on the right (untreated). Six injections were given on alternate days. Auditory brainstem response thresholds were assessed at 1 month, 2 months, and >2 months. RESULTS There was a significantly greater degree of hearing loss in the BM-treated ears compared to the untreated ears (6.48 dB hearing loss, P = .007) and in the GM-treated ears compared to untreated ears (6.59 dB hearing loss, P = .010,). However, otic GM/BM and benzalkonium chloride did not cause significant additional hearing loss compared with the untreated ears (3.56 dB hearing loss, P = .242). CONCLUSIONS Our data suggest that hearing loss caused by GM otic drops may be reduced by the inclusion of BM and benzalkonium chloride. Our finding that BM alone was associated with hearing loss suggests that the benzalkonium chloride may be the protective agent in combination otic drops.
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Affiliation(s)
- Brian W Blakley
- Department of Otolaryngology, University of Manitoba, Winnipeg, Manitoba, Canada
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Topographic and quantitative evaluation of gentamicin-induced damage to peripheral innervation of mouse cochleae. Neurotoxicology 2013; 40:86-96. [PMID: 24308912 DOI: 10.1016/j.neuro.2013.11.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 11/11/2013] [Accepted: 11/11/2013] [Indexed: 11/24/2022]
Abstract
Ototoxicity induced by aminoglycoside antibiotics appears to occur both in hair cells (HCs) and the cochlear nerves that innervate them. Although HC loss can be easily quantified, neuronal lesions are difficult to quantify because two types of afferent dendrites and two types of efferent axons are tangled beneath the hair cells. In the present study, ototoxicity was induced by gentamicin in combination with the diuretic agent furosemide. Neuronal lesions were quantified in cochlear whole-mount preparations combined with microsections across the habenular perforate (HP) openings to achieve a clear picture of the topographic relationship between neuronal damage and HC loss. Multiple immunostaining methods were employed to differentiate the two types of afferent dendrites and two types of efferent axons. The results show that co-administration of gentamicin and furosemide resulted in a typical dynamic pattern of HC loss that spread from the basal turn to the outer hair cells to the apex and inner hair cells, depending on the dose and survival time after drug administration. Lesions of the innervation appeared to occur at two stages. At the early stage (2-4 days), the loss of labeling of the two types of afferent dendrites was more obvious than the loss of labeled efferent axons. At the late stage (2-4 weeks), the loss of labeled efferent axons was more rapid. In the high-dose gentamicin group, the loss of outer HCs was congruent with afferent dendrite loss at the early stage and efferent axon loss at the late stage. In the low-dose gentamicin group, the loss of labeling for cochlear innervation was more severe and widespread. Thus, we hypothesize that the gentamicin-induced damage to cochlear innervation occurs independently of hair cell loss.
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Pavlidis P, Maurer J, Apostolidou E, Kekes G, Kouvelas D. Memantine's action against aminoglycoside-induced ototoxicity. Eur Arch Otorhinolaryngol 2013; 271:1491-6. [PMID: 23917735 DOI: 10.1007/s00405-013-2647-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 07/20/2013] [Indexed: 11/30/2022]
Abstract
The objectives of this study were (1) to assess the protective role of NMDA antagonists against the ototoxic effects of aminoglycosides, (2) to provide any possible evidence between ototoxicity due to aminoglycosides and excitotoxicity. An animal experiment was conducted. Twenty-eight, 3-month-old female New Zealand rabbits, weighing 1,000-1,500 g, were studied prospectively for 28 days after intramuscular administration of amikacin (15 mg/kg/day divided into two equal doses) for 14 days. Twenty-one rabbits were categorized into three equal treatment groups and seven animals received no medication and served as the control group. The animals of A, B and C groups were injected, intramuscularly, with amikacin 15 mg/kg/day, divided into two equal doses every day for 14 days. Animals of group A received in parallel memantine (per os) and those of group B received p.o. the same volume of placebo solution. The rabbits of the third group (group C) received on the 15th day and every 2 days for the next 2 weeks, until the day 28, memantine of the same quantity as the members of group A. Differences in DPOAE amplitudes, and therefore in cochlear activity, between group A and group B were revealed. DPOAE amplitudes of group B were further reduced compared to the respective amplitudes in rabbits of group A. No improvement was observed in DPOAE measurements performed after the discontinuation of injections. The findings in group C should be examined separately. The measurements showed apparent reversal ototoxic effects in four of the animals. The development of aminoglycoside otoprotective strategies is a primary goal in ototoxicity research. The administration of NMDA antagonists has been shown to prevent, at least to some extent, toxic damage to hair cells in guinea pigs, treated with aminoglycoside antibiotics.
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Affiliation(s)
- Pavlos Pavlidis
- ENT Department, Katholisches Klinikum, Rudolf-Virchow-Str.7, 56073, Koblenz, Germany,
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Arun P, Valiyaveettil M, Biggemann L, Alamneh Y, Wei Y, Oguntayo S, Wang Y, Long JB, Nambiar MP. Modulation of hearing related proteins in the brain and inner ear following repeated blast exposures. Interv Med Appl Sci 2012. [DOI: 10.1556/imas.4.2012.3.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
Emerging studies show that blast exposure causes traumatic brain injury (TBI) and auditory dysfunction without rupture of tympanic membrane, suggesting central auditory processing impairment after blast exposure. There is limited information on the mechanisms of blast-induced TBI and associated peripheral and central auditory processing impairments. We utilized a repetitive blast exposure mouse model to unravel the mechanisms of blast TBI and auditory impairment. C57BL/6J mice were exposed to three repeated blasts (20.6 psi) using a shock tube, and the cerebellum was subjected to proteomic analysis. The data showed that calretinin and parvalbumin, two major calcium buffering proteins, were significantly up-regulated after repeated blast exposures, and this was confirmed by Western blotting. Since these proteins are reportedly involved in auditory dysfunction, we examined the inner ear and found both calretinin and parvalbumin were up-regulated, suggesting that modulation of these proteins plays a role in blast-induced peripheral and central auditory processing impairments. Expression of cleaved caspase-3 was also up-regulated in both regions indicating ongoing cellular apoptosis, possibly due to altered calcium homeostasis. These results provide a molecular basis for changes in central and peripheral auditory processing involving abnormal calcium homeostasis resulting in hearing impairment after blast exposure.
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Affiliation(s)
- Peethambaran Arun
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
| | - Manojkumar Valiyaveettil
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
| | - Lionel Biggemann
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
| | - Yonas Alamneh
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
| | - Yanling Wei
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
| | - Samuel Oguntayo
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
| | - Ying Wang
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
| | - Joseph B. Long
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
| | - Madhusoodana P. Nambiar
- 1 Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, USA
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Matt T, Ng CL, Lang K, Sha SH, Akbergenov R, Shcherbakov D, Meyer M, Duscha S, Xie J, Dubbaka SR, Perez-Fernandez D, Vasella A, Ramakrishnan V, Schacht J, Böttger EC. Dissociation of antibacterial activity and aminoglycoside ototoxicity in the 4-monosubstituted 2-deoxystreptamine apramycin. Proc Natl Acad Sci U S A 2012; 109:10984-9. [PMID: 22699498 PMCID: PMC3390888 DOI: 10.1073/pnas.1204073109] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Aminoglycosides are potent antibacterials, but therapy is compromised by substantial toxicity causing, in particular, irreversible hearing loss. Aminoglycoside ototoxicity occurs both in a sporadic dose-dependent and in a genetically predisposed fashion. We recently have developed a mechanistic concept that postulates a key role for the mitochondrial ribosome (mitoribosome) in aminoglycoside ototoxicity. We now report on the surprising finding that apramycin, a structurally unique aminoglycoside licensed for veterinary use, shows little activity toward eukaryotic ribosomes, including hybrid ribosomes which were genetically engineered to carry the mitoribosomal aminoglycoside-susceptibility A1555G allele. In ex vivo cultures of cochlear explants and in the in vivo guinea pig model of chronic ototoxicity, apramycin causes only little hair cell damage and hearing loss but it is a potent antibacterial with good activity against a range of clinical pathogens, including multidrug-resistant Mycobacterium tuberculosis. These data provide proof of concept that antibacterial activity can be dissected from aminoglycoside ototoxicity. Together with 3D structures of apramycin-ribosome complexes at 3.5-Å resolution, our results provide a conceptual framework for further development of less toxic aminoglycosides by hypothesis-driven chemical synthesis.
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Affiliation(s)
- Tanja Matt
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006 Zürich, Switzerland
| | - Chyan Leong Ng
- Structural Studies Division, Medical Research Council (MRC) Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Kathrin Lang
- Structural Studies Division, Medical Research Council (MRC) Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Su-Hua Sha
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI 48109; and
| | - Rashid Akbergenov
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006 Zürich, Switzerland
| | - Dmitri Shcherbakov
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006 Zürich, Switzerland
| | - Martin Meyer
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006 Zürich, Switzerland
| | - Stefan Duscha
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006 Zürich, Switzerland
| | - Jing Xie
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI 48109; and
| | - Srinivas R. Dubbaka
- Laboratorium für Organische Chemie, Eidgenössische Technische Hochschule Zürich, 8093 Zürich, Switzerland
| | - Déborah Perez-Fernandez
- Laboratorium für Organische Chemie, Eidgenössische Technische Hochschule Zürich, 8093 Zürich, Switzerland
| | - Andrea Vasella
- Laboratorium für Organische Chemie, Eidgenössische Technische Hochschule Zürich, 8093 Zürich, Switzerland
| | - V. Ramakrishnan
- Structural Studies Division, Medical Research Council (MRC) Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Jochen Schacht
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI 48109; and
| | - Erik C. Böttger
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006 Zürich, Switzerland
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Feldman L, Sherman RA, Weissgarten J. N-acetylcysteine use for amelioration of aminoglycoside-induced ototoxicity in dialysis patients. Semin Dial 2012; 25:491-4. [PMID: 22708712 DOI: 10.1111/j.1525-139x.2012.01090.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Use of aminoglycoside antibiotics is associated with significant ototoxicity, especially on patients with decreased renal function. The risk of aminoglycoside ototoxicity may approach 60%. Oxidative stress has been suggested as a general mechanism of aminoglycoside ototoxicity and is prevalent in dialysis population. N-acetylcysteine (NAC) is an effective antioxidant and has been safely used in dialysis patients. New experimental and clinical data, explored in this review, provide a good case to recommend NAC administration to all dialysis patients, receiving aminoglycosides.
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Mechanisms of aminoglycoside ototoxicity and targets of hair cell protection. Int J Otolaryngol 2011; 2011:937861. [PMID: 22121370 PMCID: PMC3202092 DOI: 10.1155/2011/937861] [Citation(s) in RCA: 255] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 08/18/2011] [Indexed: 01/14/2023] Open
Abstract
Aminoglycosides are commonly prescribed antibiotics with deleterious side effects to the inner ear. Due to their popular application as a result of their potent antimicrobial activities, many efforts have been undertaken to prevent aminoglycoside ototoxicity. Over the years, understanding of the antimicrobial as well as ototoxic mechanisms of aminoglycosides has increased. These mechanisms are reviewed in regard to established and potential future targets of hair cell protection.
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Oghan F, Apuhan T, Yılmaz F. Ototoxicity caused by topical administration of gentamicin versus tobramycin in rabbits. Int J Pediatr Otorhinolaryngol 2011; 75:915-8. [PMID: 21592592 DOI: 10.1016/j.ijporl.2011.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/03/2011] [Accepted: 04/06/2011] [Indexed: 11/29/2022]
Abstract
AIM To investigate the possible differences in cochleotoxic effects in rabbits between twice-daily administration of topical gentamicin and tobramycin throughout the perforated tympanic membrane with the use of distortion-product otoacoustic emissions (DPOAEs). MATERIALS AND METHODS Twenty female rabbits were studied prospectively daily for 21 days. The rabbits' ears were divided into two groups: right and left ear groups. Twice-daily for 21 days after paracentesis, 0.3% gentamicin was administered topically in the left ears, and 0.3% tobramycin was administered topically in the right ears. For 21 days, the cochlear activity of the right and left ears of all rabbits was examined every 7 days using DPOAEs. The numerical values of the distortion product (DP) intensity recorded on days 7, 14 and 21 of drug administration were compared between the two groups. RESULTS Cochlear activity was reduced earlier in the gentamicin group in the 2-4kHz frequencies compared to the tobramycin group in the second DPOAE measurement (day 7 of the experiment). In two rabbits in the gentamicin group, the third DPOAE measurement showed that cochlear activity was reduced in all frequencies. In six rabbits in the tobramycin group, the third DPOAE measurement showed that cochlear activity was reduced in all frequencies. There was no statistical significance between the two groups except day 7 in the 2 and 3kHz frequencies (p<0.05). CONCLUSION We concluded that low frequencies (2 and 3kHz) are more sensitive to the administration of topical gentamicin than to topical tobramycin. Early cessation of tobramycin drops may be minimally cochlear toxic compared to gentamicin within the first 7 days when these drugs are misused in treating chronic otitis media.
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Affiliation(s)
- Fatih Oghan
- Department of Otorhinolaryngology, Faculty of Medicine, Dumlupinar University, Kutahya, Turkey.
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Cooper AC, Commers AR, Finkelstein M, Lipnik PG, Tollefson LM, Wilcox RA, Hoff DS. Otoacoustic Emission Screen Results in Critically Ill Neonates Who Received Gentamicin in the First Week of Life. Pharmacotherapy 2011; 31:649-57. [DOI: 10.1592/phco.31.7.649] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Suckfüll M, Althaus M, Ellers-Lenz B, Gebauer A, Görtelmeyer R, Jastreboff PJ, Moebius HJ, Rosenberg T, Russ H, Wirth Y, Krueger H. A randomized, double-blind, placebo-controlled clinical trial to evaluate the efficacy and safety of neramexane in patients with moderate to severe subjective tinnitus. BMC EAR, NOSE, AND THROAT DISORDERS 2011; 11:1. [PMID: 21223542 PMCID: PMC3031239 DOI: 10.1186/1472-6815-11-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Accepted: 01/11/2011] [Indexed: 11/14/2022]
Abstract
Background Neramexane is a new substance that exhibits antagonistic properties at α9α10 cholinergic nicotinic receptors and N-methyl-D-aspartate receptors, suggesting potential efficacy in the treatment of tinnitus. Methods A total of 431 outpatients with moderate to severe subjective tinnitus (onset 3-18 months before screening) were assigned randomly to receive either placebo or neramexane mesylate (25 mg/day, 50 mg/day and 75 mg/day) for 16 weeks, with assessment at 4-week intervals. The primary (intention-to-treat) efficacy analysis was based on the change from baseline in Week 16 in the total score of the adapted German short version of the validated Tinnitus Handicap Inventory questionnaire (THI-12). Results Compared with placebo, the largest improvement was achieved in the 50 mg/d neramexane group, followed by the 75 mg/d neramexane group. This treatment difference did not reach statistical significance at the pre-defined endpoint in Week 16 (p = 0.098 for 50 mg/d; p = 0.289 for 75 mg/d neramexane), but consistent numerical superiority of both neramexane groups compared with placebo was observed. Four weeks after the end of treatment, THI-12 scores in the 50 mg/d group were significantly better than those of the controls. Secondary efficacy variables supported this trend, with p values of < 0.05 for the 50 mg/d neramexane group associated with the functional-communicational subscores of the THI-12 and the assessments of tinnitus annoyance and tinnitus impact on life as measured on an 11-point Likert-like scale. No relevant changes were observed for puretone threshold, for tinnitus pitch and loudness match, or for minimum masking levels. The 25 mg/d neramexane group did not differ from placebo. Neramexane was generally well tolerated and had no relevant influence on laboratory values, electrocardiography and vital signs. Dizziness was the most common adverse event and showed a clear dose-dependence. Conclusions This study demonstrated the safety and tolerability of neramexane treatment in patients with moderate to severe tinnitus. The primary efficacy variable showed a trend towards improvement of tinnitus suffering in the medium- and high-dose neramexane groups. This finding is in line with consistent beneficial effects observed in secondary assessment variables. These results allow appropriate dose selection for further studies. Trial Registration ClinicalTrials.gov NCT00405886
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Affiliation(s)
- Markus Suckfüll
- University of Munich, Department of Oto-Rhino-Laryngolgy, Marchioninistraße 15, 81377 Munich, Germany.
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Ototoxicity caused by once- and twice-daily administration of amikacin in rabbits. Int J Pediatr Otorhinolaryngol 2010; 74:361-4. [PMID: 20089318 DOI: 10.1016/j.ijporl.2009.12.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 12/21/2009] [Accepted: 12/22/2009] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The cochleotoxic effects of aminoglycosides, such as amikacin, are well-established. The aim of the present study was to investigate the possible differences in cochleotoxic effects between once-daily administration (ODA) and twice-daily administration (TDA) of amikacin simulating pediatric dosing. METHODS Twenty-one rabbits were used. Seven animals received intramuscularly amikacin once daily (ODA-group) and seven received the drug twice daily (TDA-group), for a total time period of 2 weeks. All the animals were subjected to Distortion Product Otoacoustic Emissions (DPOAEs) every 3 days since beginning of the experiment. The rest 7 animals did not receive any medication and served as controls (Control group). Two measurements (7 and 14 days) were obtained following the cease of drug administration. RESULTS Reduced cochlear activity (as depicted in the respective reduced DPOAE-amplitudes) compared to the pre-treatment state was found in both ODA- and TDA-groups. Cochlear activity was reduced at a wider range of frequencies (from 593 to 4031Hz in TDA-group and from 593 to 1093Hz in ODA-group) and to a higher degree in group B than in group A. Cochlear activity was reduced earlier in ODA-group than in TDA-group. No differences to the pre-treatment state were observed in the control group. CONCLUSIONS The above findings suggest that less frequent administration in higher dose of amikacin is associated with minimal cochleotoxicity.
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Coffin AB, Reinhart KE, Owens KN, Raible DW, Rubel EW. Extracellular divalent cations modulate aminoglycoside-induced hair cell death in the zebrafish lateral line. Hear Res 2009; 253:42-51. [PMID: 19285547 DOI: 10.1016/j.heares.2009.03.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 02/11/2009] [Accepted: 03/04/2009] [Indexed: 10/21/2022]
Abstract
Aminoglycoside antibiotics cause death of sensory hair cells. Research over the past decade has identified several key players in the intracellular cascade. However, the role of the extracellular environment in aminoglycoside ototoxicity has received comparatively little attention. The present study uses the zebrafish lateral line to demonstrate that extracellular calcium and magnesium ions modulate hair cell death from neomycin and gentamicin in vivo, with high levels of either divalent cation providing significant protection. Imaging experiments with fluorescently-tagged gentamicin show that drug uptake is reduced under high calcium conditions. Treating fish with the hair cell transduction blocker amiloride also reduces aminoglycoside uptake, preventing the toxicity, and experiments with variable calcium and amiloride concentrations suggest complementary effects between the two protectants. Elevated magnesium, in contrast, does not appear to significantly attenuate drug uptake, suggesting that the two divalent cations may protect hair cells from aminoglycoside damage through different mechanisms. These results provide additional evidence for calcium- and transduction-dependent aminoglycoside uptake. Divalent cations provided differential protection from neomycin and gentamicin, with high cation concentrations almost completely protecting hair cells from neomycin and acute gentamicin toxicity, but offering reduced protection from continuous (6 h) gentamicin exposure. These experiments lend further support to the hypothesis that aminoglycoside toxicity occurs via multiple pathways in a both a drug and time course-specific manner.
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Affiliation(s)
- Allison B Coffin
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology - Head and Neck Surgery, University of Washington, Box 357923, Seattle, WA 98195, USA
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Genetic analysis of interactions with eukaryotic rRNA identify the mitoribosome as target in aminoglycoside ototoxicity. Proc Natl Acad Sci U S A 2008; 105:20888-93. [PMID: 19104050 DOI: 10.1073/pnas.0811258106] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Aminoglycoside ototoxicity has been related to a surprisingly large number of cellular structures and metabolic pathways. The finding that patients with mutations in mitochondrial rRNA are hypersusceptible to aminoglycoside-induced hearing loss has indicated a possible role for mitochondrial protein synthesis. To study the molecular interaction of aminoglycosides with eukaryotic ribosomes, we made use of the observation that the drug binding site is a distinct domain defined by the small subunit rRNA, and investigated drug susceptibility of bacterial hybrid ribosomes carrying various alleles of the eukaryotic decoding site. Compared to hybrid ribosomes with the A site of human cytosolic ribosomes, susceptibility of mitochondrial hybrid ribosomes to various aminoglycosides correlated with the relative cochleotoxicity of these drugs. Sequence alterations that correspond to the mitochondrial deafness mutations A1555G and C1494T increased drug-binding and rendered the ribosomal decoding site hypersusceptible to aminoglycoside-induced mistranslation and inhibition of protein synthesis. Our results provide experimental support for aminoglycoside-induced dysfunction of the mitochondrial ribosome. We propose a pathogenic mechanism in which interference of aminoglycosides with mitochondrial protein synthesis exacerbates the drugs' cochlear toxicity, playing a key role in sporadic dose-dependent and genetically inherited, aminoglycoside-induced deafness.
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Abstract
Guided by findings from neural imaging and population responses in humans, where tinnitus is well characterized, several morphological and physiological substrates of tinnitus in animal studies are reviewed. These include changes in ion channels, receptor systems, single unit firing rate, and population responses. Most findings in humans can be interpreted as resulting from increased neural synchrony.
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Affiliation(s)
- Jos J Eggermont
- Department of Physiology & Biophysics, University of Calgary, Calgary, AB, Canada.
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Qi W, Ding D, Salvi RJ. Cytotoxic effects of dimethyl sulphoxide (DMSO) on cochlear organotypic cultures. Hear Res 2007; 236:52-60. [PMID: 18207679 DOI: 10.1016/j.heares.2007.12.002] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 11/03/2007] [Accepted: 12/06/2007] [Indexed: 10/22/2022]
Abstract
The amphipathic molecule dimethyl sulphoxide (DMSO) is a solvent often used to dissolve compounds applied to the inner ear; however, little is known about its potential cytotoxic side effects. To address this question, we applied 0.1-6% DMSO for 24h to cochlear organotypic cultures from postnatal day 3 rats and examined its cytotoxic effects. DMSO concentrations of 0.1% and 0.25% caused little or no damage. However, concentrations between 0.5% and 6% resulted in stereocilia damage, hair cell swelling and a dose-dependent loss of hair cells. Hair cell damage began in the basal turn of the cochlea and spread towards the apex with increasing concentration. Surprisingly, DMSO-induced damage was greater for inner hair cells than outer hair cell whereas nearby supporting cells were largely unaffected. Most hair cell death was associated with nuclear shrinkage and fragmentation, morphological features consistent with apoptosis. DMSO treatment induced TUNEL-positive staining in many hair cells and activated both initiator caspase-9 and caspase-8 and executioner caspase-3; this suggests that apoptosis is initiated by both intrinsic mitochondrial and extrinsic membrane cell death signaling pathways.
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Affiliation(s)
- Weidong Qi
- Center for Hearing and Deafness, State University of New York at Buffalo, 137Cary Hall, Buffalo, NY 14214, USA
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Adeno-associated virus-mediated Bcl-xL prevents aminoglycoside-induced hearing loss in mice. Chin Med J (Engl) 2007. [DOI: 10.1097/00029330-200707020-00006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Lecain E, Omri B, Behar-Cohen F, Tran Ba Huy P, Crisanti P. The role of PKCzeta in amikacin-induced apoptosis in the cochlea: prevention by aspirin. Apoptosis 2007; 12:333-42. [PMID: 17191118 DOI: 10.1007/s10495-006-0580-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Aminoglycoside antibiotics are ototoxic, inducing irreversible sensorineural hearing loss mediated by oxidative and excitotoxic stresses. The NF-kappaB pathway is involved in the response to aminoglycoside damage in the cochlea. However, the molecular mechanisms of this ototoxicity remain unclear. We investigated the expression of PKCzeta, a key regulator of NF-kappaB activation, in response to aminoglycoside treatment. Amikacin induced PKCzeta cleavage and nuclear translocation. These events were concomitant with chromatin condensation and paralleled the decrease in NF-kappaB (p65) levels in the nucleus. Amikacin also induced the nuclear translocation of apoptotic inducing factor (AIF). Prior treatment with aspirin prevented PKCzeta cleavage and nuclear translocation. Thus, aspirin counteracts the early effects of amikacin, thereby protecting hair cells and spiral ganglion neurons. These results demonstrate that PKCzeta acts as sentinel connecting specific survival pathways to mediate cellular responses to amikacin ototoxicity.
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Affiliation(s)
- Eric Lecain
- Hôpital Lariboisière, Service ORL, 2 rue Ambroise Paré, 75010, Paris, France
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Haynes DS, Rutka J, Hawke M, Roland PS. Ototoxicity of Ototopical Drops—An Update. Otolaryngol Clin North Am 2007; 40:669-83, xi. [PMID: 17544701 DOI: 10.1016/j.otc.2007.03.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Various topical preparations are widely used for treating external otitis, acute otitis media with perforation, post-tympanostomy tube otorrhea, and chronic suppurative otitis media. Solutions and suspensions that enter the middle ear through a perforated tympanic membrane can reach the inner ear by crossing through the round window membrane. The safety of various components of otic solutions used in this way, particularly aminoglycosides, corticosteroids, solvents, and preservatives, has been questioned in light of their ototoxic potential. The authors' objective is to review the literature discussing the safety of commonly used classes of otic preparations in settings in which the constituents can access the middle and inner ear in high concentrations and discuss their clinical experience with ototoxicity and experience with medical-legal issues.
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Affiliation(s)
- David S Haynes
- The Otology Group of Vanderbilt, Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center, Medical Center East S. Tower 7209, 1215 21st Avenue South, Nashville, TN 37232-5555, USA.
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Glowatzki E, Cheng N, Hiel H, Yi E, Tanaka K, Ellis-Davies GCR, Rothstein JD, Bergles DE. The glutamate-aspartate transporter GLAST mediates glutamate uptake at inner hair cell afferent synapses in the mammalian cochlea. J Neurosci 2006; 26:7659-64. [PMID: 16855093 PMCID: PMC6674291 DOI: 10.1523/jneurosci.1545-06.2006] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Ribbon synapses formed between inner hair cells (IHCs) and afferent dendrites in the mammalian cochlea can sustain high rates of release, placing strong demands on glutamate clearance mechanisms. To investigate the role of transporters in glutamate removal at these synapses, we made whole-cell recordings from IHCs, afferent dendrites, and glial cells adjacent to IHCs [inner phalangeal cells (IPCs)] in whole-mount preparations of rat organ of Corti. Focal application of the transporter substrate D-aspartate elicited inward currents in IPCs, which were larger in the presence of anions that permeate the transporter-associated anion channel and blocked by the transporter antagonist D,L-threo-beta-benzyloxyaspartate. These currents were produced by glutamate-aspartate transporters (GLAST) (excitatory amino acid transporter 1) because they were weakly inhibited by dihydrokainate, an antagonist of glutamate transporter-1 (excitatory amino acid transporter 2) and were absent from IPCs in GLAST-/- cochleas. Furthermore, D-aspartate-induced currents in outside-out patches from IPCs exhibited larger steady-state currents than responses elicited by L-glutamate, a prominent feature of GLAST, and examination of cochlea from GLAST-Discosoma red (DsRed) promoter reporter mice revealed that DsRed expression was restricted to IPCs and other supporting cells surrounding IHCs. Saturation of transporters by photolysis of caged D-aspartate failed to elicit transporter currents in IHCs, as did local application of D-aspartate to afferent terminals, indicating that neither presynaptic nor postsynaptic membranes are major sites for glutamate removal. These data indicate that GLAST in supporting cells is responsible for transmitter uptake at IHC afferent synapses.
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Goldman ME, Cregar L, Nguyen D, Simo O, O'Malley S, Humphreys T. Cationic polyamines inhibit anthrax lethal factor protease. BMC Pharmacol 2006; 6:8. [PMID: 16762077 PMCID: PMC1513218 DOI: 10.1186/1471-2210-6-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Accepted: 06/08/2006] [Indexed: 11/12/2022] Open
Abstract
Background Anthrax is a human disease that results from infection by the bacteria, Bacillus anthracis and has recently been used as a bioterrorist agent. Historically, this disease was associated with Bacillus spore exposure from wool or animal carcasses. While current vaccine approaches (targeted against the protective antigen) are effective for prophylaxis, multiple doses must be injected. Common antibiotics that block the germination process are effective but must be administered early in the infection cycle. In addition, new therapeutics are needed to specifically target the proteolytic activity of lethal factor (LF) associated with this bacterial infection. Results Using a fluorescence-based assay to identify and characterize inhibitors of anthrax lethal factor protease activity, we identified several chemically-distinct classes of inhibitory molecules including polyamines, aminoglycosides and cationic peptides. In these studies, spermine was demonstrated for the first time to inhibit anthrax LF with a Ki value of 0.9 ± 0.09 μM (mean ± SEM; n = 3). Additional linear polyamines were also active as LF inhibitors with lower potencies. Conclusion Based upon the studies reported herein, we chose linear polyamines related to spermine as potential lead optimization candidates and additional testing in cell-based models where cell penetration could be studied. During our screening process, we reproducibly demonstrated that the potencies of certain compounds, including neomycin but not neamine or spermine, were different depending upon the presence or absence of nucleic acids. Differential sensitivity to the presence/absence of nucleic acids may be an additional point to consider when comparing various classes of active compounds for lead optimization.
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Affiliation(s)
| | - Lynne Cregar
- Hawaii Biotech, Inc., 99-193 Aiea Heights Dr., Aiea, HI 96701, USA
| | - Dominique Nguyen
- Hawaii Biotech, Inc., 99-193 Aiea Heights Dr., Aiea, HI 96701, USA
| | - Ondrej Simo
- Hawaii Biotech, Inc., 99-193 Aiea Heights Dr., Aiea, HI 96701, USA
| | - Sean O'Malley
- Hawaii Biotech, Inc., 99-193 Aiea Heights Dr., Aiea, HI 96701, USA
| | - Tom Humphreys
- Hawaii Biotech, Inc., 99-193 Aiea Heights Dr., Aiea, HI 96701, USA
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Saxena AK. Characteristics of ototoxicity of aminoglycosides "locked" to prevent hemodialysis catheter-related infections. Hemodial Int 2006; 10:94. [PMID: 16441834 DOI: 10.1111/j.1542-4758.2006.01181.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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