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Tang Y, Xu H, Wang X, Dong S, Guo L, Zhang S, Yang X, Liu C, Jiang X, Kan M, Wu S, Zhang J, Xu C. Advances in preparation and application of antibacterial hydrogels. J Nanobiotechnology 2023; 21:300. [PMID: 37633883 PMCID: PMC10463510 DOI: 10.1186/s12951-023-02025-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 07/24/2023] [Indexed: 08/28/2023] Open
Abstract
Bacterial infections, especially those caused by drug-resistant bacteria, have seriously threatened human life and health. There is urgent to develop new antibacterial agents to reduce the problem of antibiotics. Biomedical materials with good antimicrobial properties have been widely used in antibacterial applications. Among them, hydrogels have become the focus of research in the field of biomedical materials due to their unique three-dimensional network structure, high hydrophilicity, and good biocompatibility. In this review, the latest research progresses about hydrogels in recent years were summarized, mainly including the preparation methods of hydrogels and their antibacterial applications. According to their different antibacterial mechanisms, several representative antibacterial hydrogels were introduced, such as antibiotics loaded hydrogels, antibiotic-free hydrogels including metal-based hydrogels, antibacterial peptide and antibacterial polymers, stimuli-responsive smart hydrogels, and light-mediated hydrogels. In addition, we also discussed the applications and challenges of antibacterial hydrogels in biomedicine, which are expected to provide new directions and ideas for the application of hydrogels in clinical antibacterial therapy.
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Affiliation(s)
- Yixin Tang
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Huiqing Xu
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Xue Wang
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Shuhan Dong
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
- Department of Preventive Medicine, School of Public Health, Jilin University, Changchun, 130021 Jilin China
| | - Lei Guo
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Shichen Zhang
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
- Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Jilin University, Changchun, 130021 Jilin China
| | - Xi Yang
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Chang Liu
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Xin Jiang
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Mujie Kan
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Shanli Wu
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Jizhou Zhang
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
| | - Caina Xu
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun, 130021 Jilin China
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Bennet BM, Pardo ID, Assaf BT, Buza E, Cramer S, Crawford LK, Engelhardt JA, Grubor B, Morrison JP, Osborne TS, Sharma AK, Bolon B. Scientific and Regulatory Policy Committee Points to Consider: Sampling, Processing, Evaluation, Interpretation, and Reporting of Test Article-Related Ganglion Pathology for Nonclinical Toxicity Studies. Toxicol Pathol 2023; 51:176-204. [PMID: 37489508 DOI: 10.1177/01926233231179707] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
Certain biopharmaceutical products consistently affect dorsal root ganglia, trigeminal ganglia, and/or autonomic ganglia. Product classes targeting ganglia include antineoplastic chemotherapeutics, adeno-associated virus-based gene therapies, antisense oligonucleotides, and anti-nerve growth factor agents. This article outlines "points to consider" for sample collection, processing, evaluation, interpretation, and reporting of ganglion findings; these points are consistent with published best practices for peripheral nervous system evaluation in nonclinical toxicity studies. Ganglion findings often occur as a combination of neuronal injury (e.g., degeneration, necrosis, and/or loss) and/or glial effects (e.g., increased satellite glial cell cellularity) with leukocyte accumulation (e.g., mononuclear cell infiltration or inflammation). Nerve fiber degeneration and/or glial reactions may be seen in nerves, dorsal spinal nerve roots, spinal cord, and occasionally brainstem. Interpretation of test article (TA)-associated effects may be confounded by incidental background changes or experimental procedure-related changes and limited historical control data. Reports should describe findings at these sites, any TA relationship, and the criteria used for assigning severity grades. Contextualizing adversity of ganglia findings can require a weight-of-evidence approach because morphologic changes of variable severity occur in ganglia but often are not accompanied by observable overt in-life functional alterations detectable by conventional behavioral and neurological testing techniques.
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Affiliation(s)
| | | | | | - Elizabeth Buza
- University of Pennsylvania, Gene Therapy Program, Philadelphia, Pennsylvania, USA
| | | | - LaTasha K Crawford
- University of Wisconsin-Madison, School of Veterinary Medicine, Madison, Wisconsin, USA
| | | | | | - James P Morrison
- Charles River Laboratories, Inc., Shrewsbury, Massachusetts, USA
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Cutri RM, Lin J, Nguyen NV, Shakya D, Shibata SB. Neomycin-Induced Deafness in Neonatal Mice. J Neurosci Methods 2023; 391:109852. [PMID: 37031766 DOI: 10.1016/j.jneumeth.2023.109852] [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: 02/02/2023] [Revised: 03/26/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023]
Abstract
BACKGROUND Hearing impairment is a rising public health issue, and current therapeutics fail to restore normal auditory sensation. Animal models are essential to a better understanding of the pathophysiology of deafness and developing therapeutics to restore hearing. NEW METHODS Wild-type CBA/CaJ neonatal mice P2-5 were used in this study. Neomycin suspension (500nl of 50 or 100mg/ml) was micro-injected into the endolymphatic space. Cochlear morphology was examined 3 and 7 days after injection; hair cell (HC) loss, supporting cell morphology, and neurite denervation pattern were assessed with whole-mounts. At 2 and 4 weeks post-injection, the spiral ganglion neuron (SGN) density was analyzed with cryostat sections. Audiometric responses were measured with auditory brain response (ABR) at 4 weeks. RESULTS Rapid and complete degeneration of the inner and outer HCs occurred as early as 3 days post-injection. Subsequently, time- and dose-dependent degeneration patterns were observed along the axis of the cochlear membranous labyrinth forming a flat epithelium. Likewise, the SGN histology demonstrated significant cell density reduction at 2 and 4 weeks. The ABR threshold measurements confirmed profound deafness at 4 weeks. COMPARISON WITH EXISTING METHODS Compared to previously described local and systemic aminoglycoside injections, this method provides a reliable, robust, and rapid deafening model with a single infusion of neomycin in neonatal mice. This model also allows for investigating the effects of inner ear damage during auditory maturation. CONCLUSIONS A single injection of neomycin into the endolymphatic space induces robust HC loss and denervation in neonatal mice.
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Affiliation(s)
- Raffaello M Cutri
- Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Joshua Lin
- Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Nhi V Nguyen
- Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA
| | - Dejan Shakya
- Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Seiji B Shibata
- Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA.
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Fogliano C, Motta CM, Avallone B. Salicylate attenuates gentamicin-induced ototoxicity and facilitates the recovery in the basilar papilla of the lizard Podarcis siculus. Neurotoxicology 2022; 93:301-310. [DOI: 10.1016/j.neuro.2022.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/24/2022] [Accepted: 10/24/2022] [Indexed: 11/15/2022]
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Núñez-Batalla F, Jáudenes-Casaubón C, Sequí-Canet JM, Vivanco-Allende A, Zubicaray-Ugarteche J. Ototoxicity in childhood: Recommendations of the CODEPEH (Commission for the Early Detection of Childhood Hearing Loss) for prevention and early diagnosis. ACTA OTORRINOLARINGOLOGICA ESPANOLA 2022; 73:255-265. [PMID: 35872300 DOI: 10.1016/j.otoeng.2022.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/18/2021] [Indexed: 11/22/2022]
Abstract
Ototoxicity is defined as the damage, reversible or irreversible, produced in the inner ear by various substances that are called ototoxic and that can cause hearing loss and/or an alteration of the vestibular system. Permanent hearing loss significantly affects quality of life and is especially important in children. The lack or delay in its detection is frequent, since it often progresses in an inconspicuous manner until it affects communication and overall development. This impact can be minimized by following a strategy of audiological monitoring of ototoxicity, which allows for its early detection and treatment. This document recommends that children who are going to be treated with cisplatin or aminoglycosides be monitored. This CODEPEH review and recommendation document focuses on the early detection, prophylaxis, otoprotection, monitoring and treatment of ototoxicity caused by aminoglycosides and platinum-based antineoplastics in the paediatric population.
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Ototoxicidad en la edad pediátrica: recomendaciones de la CODEPEH (Comisión para la Detección Precoz de la Hipoacusia infantil) para su prevención y diagnóstico precoz. ACTA OTORRINOLARINGOLOGICA ESPANOLA 2022. [DOI: 10.1016/j.otorri.2021.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kim J, Hemachandran S, Cheng AG, Ricci AJ. Identifying targets to prevent aminoglycoside ototoxicity. Mol Cell Neurosci 2022; 120:103722. [PMID: 35341941 PMCID: PMC9177639 DOI: 10.1016/j.mcn.2022.103722] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/14/2022] [Accepted: 03/19/2022] [Indexed: 12/21/2022] Open
Abstract
Aminoglycosides are potent antibiotics that are commonly prescribed worldwide. Their use carries significant risks of ototoxicity by directly causing inner ear hair cell degeneration. Despite their ototoxic side effects, there are currently no approved antidotes. Here we review recent advances in our understanding of aminoglycoside ototoxicity, mechanisms of drug transport, and promising sites for intervention to prevent ototoxicity.
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Affiliation(s)
- Jinkyung Kim
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sriram Hemachandran
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alan G Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Anthony J Ricci
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Onohuean H, Adisa RA, Alagbonsi AI. Anti-apoptotic effect of Buchholzia coriacea Engl. stem back extracts on AsPC-1 and mechanisms of action. BMC Complement Med Ther 2021; 21:258. [PMID: 34627212 PMCID: PMC8501612 DOI: 10.1186/s12906-021-03433-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 09/15/2021] [Indexed: 12/24/2022] Open
Abstract
Ethnopharmacological relevance Buchholzia coriacea Engl. is popularly called wonderful cola due to its wide ethnomedicinal use for the treatment of various ailments. We investigated the possible cytotoxic effect of its various fractions on human pancreatic cancer cell (AsPC-1) and also determined its mechanisms of action. Materials and methods The AsPC-1 cells were cultivated and separately treated with 5-fluorouracil (5-FU) or Buchholzia coriacea Engl. bark (BC) (ethanol, aqueous, chloroform or ethyl acetate extract) for 72 h. Cell viability, caspase 3 and mitochondrial membrane potential (ΔΨm) were determined in vitro after the treatment. Nitric oxide (NO) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals’ scavenging property, ferric reducing power and lipid peroxidation assays were also done to examine the antioxidant effect of BC in vitro. Results Various extracts of BC, especially at 2500 μg/ml and 5000 μg/ml, increased the AsPC-1 viability while 5-FU decreased it. The activity of caspase 3 was increased by 5-FU but reduced by all concentrations of various extracts of BC. Incubation of AsPC-1 with 5-FU showed the majority of cells having the monomeric form of JC-1 dye (bright green fluorescence), which indicated de-energized mitochondria. However, fluorescence photomicrograph of cells incubated with different concentrations (20, 40 and 100 μg/ml) of BC extracts (aqueous, ethanol, chloroform and ethyl acetate) showed strong JC-1 aggregation (yellow), which indicated mitochondria with intact membrane potentials. BC extracts also scavenged NO and DPPH radicals, inhibited lipid peroxidation and increased ferric reduction, though not as much as ascorbic acid. Conclusion This study suggests that BC elicits anti-apoptotic activity in AsPC-1 by increasing cell viability, decreasing caspase 3 activity, stabilizing the ∆Ψm, and scavenging free radicals. Even though BC is used ethnomedicinally as anti-cancer agent, our findings in the present study suggest that it has pro-cancer potential in-vitro, especially on pancreatic cells. Its anti-apoptotic activity in AsPC-1 could be of clinical significance, especially to counteract the effect of apoptotic agents on pancreatic cells.
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Affiliation(s)
- Hope Onohuean
- Biopharmaceutics unit, Department of Pharmacology and Toxicology, Kampala International University Western Campus, Ishaka-Bushenyi, Uganda. .,Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Idi-Araba, Lagos State, Nigeria.
| | - Rahmat Adetutu Adisa
- Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Idi-Araba, Lagos State, Nigeria
| | - Abdullateef Isiaka Alagbonsi
- Department of Clinical Biology (Physiology Unit), School of Medicine and Pharmacy, University of Rwanda College of Medicine and Health Sciences, Huye, Rwanda
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Gu X, Wang D, Xu Z, Wang J, Guo L, Chai R, Li G, Shu Y, Li H. Prevention of acquired sensorineural hearing loss in mice by in vivo Htra2 gene editing. Genome Biol 2021; 22:86. [PMID: 33752742 PMCID: PMC7983387 DOI: 10.1186/s13059-021-02311-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 03/08/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Aging, noise, infection, and ototoxic drugs are the major causes of human acquired sensorineural hearing loss, but treatment options are limited. CRISPR/Cas9 technology has tremendous potential to become a new therapeutic modality for acquired non-inherited sensorineural hearing loss. Here, we develop CRISPR/Cas9 strategies to prevent aminoglycoside-induced deafness, a common type of acquired non-inherited sensorineural hearing loss, via disrupting the Htra2 gene in the inner ear which is involved in apoptosis but has not been investigated in cochlear hair cell protection. RESULTS The results indicate that adeno-associated virus (AAV)-mediated delivery of CRISPR/SpCas9 system ameliorates neomycin-induced apoptosis, promotes hair cell survival, and significantly improves hearing function in neomycin-treated mice. The protective effect of the AAV-CRISPR/Cas9 system in vivo is sustained up to 8 weeks after neomycin exposure. For more efficient delivery of the whole CRISPR/Cas9 system, we also explore the AAV-CRISPR/SaCas9 system to prevent neomycin-induced deafness. The in vivo editing efficiency of the SaCas9 system is 1.73% on average. We observed significant improvement in auditory brainstem response thresholds in the injected ears compared with the non-injected ears. At 4 weeks after neomycin exposure, the protective effect of the AAV-CRISPR/SaCas9 system is still obvious, with the improvement in auditory brainstem response threshold up to 50 dB at 8 kHz. CONCLUSIONS These findings demonstrate the safe and effective prevention of aminoglycoside-induced deafness via Htra2 gene editing and support further development of the CRISPR/Cas9 technology in the treatment of non-inherited hearing loss as well as other non-inherited diseases.
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Affiliation(s)
- Xi Gu
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031 China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032 China
- Department of Otolaryngology, the First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005 China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031 China
| | - Daqi Wang
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031 China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032 China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031 China
| | - Zhijiao Xu
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031 China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032 China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031 China
| | - Jinghan Wang
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031 China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032 China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031 China
| | - Luo Guo
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031 China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032 China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031 China
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096 China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001 China
- Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, China
| | - Genglin Li
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031 China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032 China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031 China
| | - Yilai Shu
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031 China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032 China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031 China
| | - Huawei Li
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031 China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032 China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031 China
- The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032 China
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Qian X, He Z, Wang Y, Chen B, Hetrick A, Dai C, Chi F, Li H, Ren D. Hair cell uptake of gentamicin in the developing mouse utricle. J Cell Physiol 2020; 236:5235-5252. [PMID: 33368220 DOI: 10.1002/jcp.30228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 11/27/2020] [Accepted: 12/08/2020] [Indexed: 12/27/2022]
Abstract
Intratympanic injection of gentamicin has proven to be an effective therapy for intractable vestibular dysfunction. However, most studies to date have focused on the cochlea, so little is known about the distribution and uptake of gentamicin by the counterpart of the auditory system, specifically vestibular hair cells (HCs). Here, with a combination of in vivo and in vitro approaches, we used a gentamicin-Texas Red (GTTR) conjugate to investigate the mechanisms of gentamicin vestibulotoxicity in the developing mammalian utricular HCs. In vivo, GTTR fluorescence was concentrated in the apical cytoplasm and the cellular membrane of neonatal utricular HCs, but scarce in the nucleus of HCs and supporting cells. Quantitative analysis showed the GTTR uptake by striolar HCs was significantly higher than that in the extrastriola. In addition, the GTTR fluorescence intensity in the striola was increased gradually from 1 to 8 days, peaking at 8-9 days postnatally. In vitro, utricle explants were incubated with GTTR and candidate uptake conduits, including mechanotransduction (MET) channels and endocytosis in the HC, were inhibited separately. GTTR uptake by HCs could be inhibited by quinine, a blocker of MET channels, under both normal and stressed conditions. Meanwhile, endocytic inhibition only reduced GTTR uptake in the CoCl2 hypoxia model. In sum, the maturation of MET channels mediated uptake of GTTR into vestibular HCs. Under stressed conditions, MET channels play a pronounced role, manifested by channel-dependent stress enhanced GTTR permeation, while endocytosis participates in GTTR entry in a more selective manner.
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Affiliation(s)
- Xiaoqing Qian
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Ziyu He
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Yanmei Wang
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Binjun Chen
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Alisa Hetrick
- Research Service, VA Loma Linda Healthcare System, Loma Linda, California, USA
| | - Chunfu Dai
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Fanglu Chi
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Hongzhe Li
- Research Service, VA Loma Linda Healthcare System, Loma Linda, California, USA.,Department of Otolaryngology-Head and Neck Surgery, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Dongdong Ren
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
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Chitosan-Gentamicin Conjugate Hydrogel Promoting Skin Scald Repair. Mar Drugs 2020; 18:md18050233. [PMID: 32365733 PMCID: PMC7281128 DOI: 10.3390/md18050233] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/23/2020] [Accepted: 04/27/2020] [Indexed: 12/11/2022] Open
Abstract
Our earlier research indicated that chitosan-gentamicin conjugate (CS-GT) possesses superior antimicrobial activity and good water solubility. To develop CS-GT-based scald dressings, the antibacterial properties of CS-GT were further studied, and the biosafety of CS-GT and the healing mechanism of CS-GT hydrogel was systematically explored in this article. It was found that cell viability shows a declined inclination with the prolonged culture time and the increased concentration of CS-GT. After three day’s culture, the cell viability could still remain at 79.72% when CS-GT concentration was as high as 1000 μg/mL. On the other hand, the hemolysis rate of CS-GT was lower than 5% when its concentration is 800 μg/mL. Therefore CS-GT has good cytocompatibility and hemocompatibility. A wound-healing experiment has shown that the skin healing rate of CS-GT hydrogel was the highest at 99.61%, followed by the positive control (wet burn ointment) 94.98%, GT hydrogel 87.50%, and matrix 77.39%. The blank control group, however, possessed the lowest healing rate of 75.45%. Further analysis indicated that CS-GT hydrogel could promote the synthesis of total protein (TP) in skin granulation tissue, resulting in the enhanced hydroxyproline (HYP) content, which facilitated collagen fibrogenesis, reduced cytokine expression in an inflammatory response, and, ultimately, accelerated wound healing. To sum up, CS-GT hydrogel is a promising scald dressing.
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Forge A, Jagger DJ, Gale JE. Restoring the balance: regeneration of hair cells in the vestibular system of the inner ear. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2019.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Systemic Fluorescent Gentamicin Enters Neonatal Mouse Hair Cells Predominantly Through Sensory Mechanoelectrical Transduction Channels. J Assoc Res Otolaryngol 2020; 21:137-149. [PMID: 32152768 DOI: 10.1007/s10162-020-00746-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 02/10/2020] [Indexed: 01/25/2023] Open
Abstract
Systemically administered aminoglycoside antibiotics can enter inner ear hair cells and trigger apoptosis. However, the in vivo route(s) by which aminoglycoside antibiotics enter hair cells remains controversial. Aminoglycosides can enter mouse hair cells by endocytosis or by permeation through transmembrane ion channels such as sensory mechanoelectrical transduction (MET) channels, transient receptor potential (TRP) channels, P2X channels, Piezo2-containing ion channels, or a combination of these routes. Transmembrane channel-like 1 (TMC1) and TMC2 are essential for sensory MET and appear to be the pore-forming components of sensory MET channels. The present study tested the hypothesis that systemic fluorescent gentamicin enters mouse hair cells predominantly through sensory MET channels. We employed Tmc1Δ, Tmc2Δ, and Tmc1::mCherry mice. In Tmc1::mCherry mice, the transgene was integrated on the X chromosome, resulting in mosaic expression of TMC1-mCherry in the hair cells of female heterozygous mice. After systemic administration of gentamicin-conjugated Texas Red (GTTR) into Tmc1Δ;Tmc2Δ mice and wild-type mice at postnatal day 4 (P4), robust GTTR fluorescence was detected in wild-type hair cells, whereas little or no GTTR fluorescence was detected in Tmc1Δ;Tmc2Δ hair cells. When GTTR was injected into developing mice at P0, P2, P4, or P6, the GTTR fluorescent intensity gradually increased from P0 to P4 in wild-type hair cells, whereas the intensity was stably low from P0 through P6 in Tmc1Δ;Tmc2Δ hair cells. The increase in the GTTR intensity coincided with the spatio-temporal onset of sensory MET in wild-type hair cells. In Tmc1::mCherry cochleae, only hair cells that showed a significant uptake of systemic GTTR took up FM1-43. Transmission electron microscopy could detect no disruption of normal endocytosis at the apical surface of Tmc1Δ;Tmc2Δ hair cells in vitro. These results provide substantial novel evidence that in vivo gentamicin enters neonatal mouse hair cells predominantly through sensory MET channels and not via endocytosis.
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Drug-induced Stress Granule Formation Protects Sensory Hair Cells in Mouse Cochlear Explants During Ototoxicity. Sci Rep 2019; 9:12501. [PMID: 31467369 PMCID: PMC6715625 DOI: 10.1038/s41598-019-48393-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/22/2019] [Indexed: 01/08/2023] Open
Abstract
Stress granules regulate RNA translation during cellular stress, a mechanism that is generally presumed to be protective, since stress granule dysregulation caused by mutation or ageing is associated with neurodegenerative disease. Here, we investigate whether pharmacological manipulation of the stress granule pathway in the auditory organ, the cochlea, affects the survival of sensory hair cells during aminoglycoside ototoxicity, a common cause of acquired hearing loss. We show that hydroxamate (-)-9, a silvestrol analogue that inhibits eIF4A, induces stress granule formation in both an auditory cell line and ex-vivo cochlear cultures and that it prevents ototoxin-induced hair-cell death. In contrast, preventing stress granule formation using the small molecule inhibitor ISRIB increases hair-cell death. Furthermore, we provide the first evidence of stress granule formation in mammalian hair cells in-vivo triggered by aminoglycoside treatment. Our results demonstrate that pharmacological induction of stress granules enhances cell survival in native-tissue, in a clinically-relevant context. This establishes stress granules as a viable therapeutic target not only for hearing loss but also other neurodegenerative diseases.
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15
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Kitcher SR, Kirkwood NK, Camci ED, Wu P, Gibson RM, Redila VA, Simon JA, Rubel EW, Raible DW, Richardson GP, Kros CJ. ORC-13661 protects sensory hair cells from aminoglycoside and cisplatin ototoxicity. JCI Insight 2019; 4:126764. [PMID: 31391343 PMCID: PMC6693895 DOI: 10.1172/jci.insight.126764] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 07/09/2019] [Indexed: 12/14/2022] Open
Abstract
Aminoglycoside (AG) antibiotics are widely used to prevent life-threatening infections, and cisplatin is used in the treatment of various cancers, but both are ototoxic and result in loss of sensory hair cells from the inner ear. ORC-13661 is a new drug that was derived from PROTO-1, a compound first identified as protective in a large-scale screen utilizing hair cells in the lateral line organs of zebrafish larvae. Here, we demonstrate, in zebrafish larvae and in mouse cochlear cultures, that ORC-13661 provides robust protection of hair cells against both ototoxins, the AGs and cisplatin. ORC-13661 also prevents both hearing loss in a dose-dependent manner in rats treated with amikacin and the loading of neomycin-Texas Red into lateral line hair cells. In addition, patch-clamp recordings in mouse cochlear cultures reveal that ORC-13661 is a high-affinity permeant blocker of the mechanoelectrical transducer (MET) channel in outer hair cells, suggesting that it may reduce the toxicity of AGs by directly competing for entry at the level of the MET channel and of cisplatin by a MET-dependent mechanism. ORC-13661 is therefore a promising and versatile protectant that reversibly blocks the hair cell MET channel and operates across multiple species and toxins. Candidate drug ORC-13661 robustly protects against ototoxicity by aminoglycoside antibiotics and cisplatin by reversibly blocking mechanotransduction of sensory hair cells.
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Affiliation(s)
- Siân R Kitcher
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Nerissa K Kirkwood
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Esra D Camci
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington, USA
| | - Patricia Wu
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington, USA.,Department of Biological Structure, University of Washington, Seattle, Washington, USA
| | - Robin M Gibson
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington, USA
| | - Van A Redila
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington, USA
| | - Julian A Simon
- Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Edwin W Rubel
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington, USA
| | - David W Raible
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington, USA.,Department of Biological Structure, University of Washington, Seattle, Washington, USA
| | - Guy P Richardson
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Corné J Kros
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, United Kingdom
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16
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Guo J, Chai R, Li H, Sun S. Protection of Hair Cells from Ototoxic Drug-Induced Hearing Loss. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1130:17-36. [PMID: 30915699 DOI: 10.1007/978-981-13-6123-4_2] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Hair cells are specialized sensory epithelia cells that receive mechanical sound waves and convert them into neural signals for hearing, and these cells can be killed or damaged by ototoxic drugs, including many aminoglycoside antibiotics, platinum-based anticancer agents, and loop diuretics, leading to drug-induced hearing loss. Studies of therapeutic approaches to drug-induced hearing loss have been hampered by the limited understanding of the biological mechanisms that protect and regenerate hair cells. This review briefly discusses some of the most common ototoxic drugs and describes recent research concerning the mechanisms of ototoxic drug-induced hearing loss. It also highlights current developments in potential therapies and explores current clinical treatments for patients with hearing impairments.
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Affiliation(s)
- Jin Guo
- Key Laboratory of Hearing Medicine of NHFPC, ENT Institute and Otorhinolaryngology Department, Shanghai Engineering Research Centre of Cochlear Implant, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Renjie Chai
- Key Laboratory of Hearing Medicine of NHFPC, ENT Institute and Otorhinolaryngology Department, Shanghai Engineering Research Centre of Cochlear Implant, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China.,MOE Key Laboratory for Developmental Genes and Human Disease, Institute of Life Sciences, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Huawei Li
- Key Laboratory of Hearing Medicine of NHFPC, ENT Institute and Otorhinolaryngology Department, Shanghai Engineering Research Centre of Cochlear Implant, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Shan Sun
- Key Laboratory of Hearing Medicine of NHFPC, ENT Institute and Otorhinolaryngology Department, Shanghai Engineering Research Centre of Cochlear Implant, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China.
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17
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Werner M, Van De Water TR, Stenlund H, Berggren D. Ultrastructural Characterization of Stem Cell-Derived Replacement Vestibular Hair Cells Within Ototoxin-Damaged Rat Utricle Explants. Anat Rec (Hoboken) 2019; 303:506-515. [PMID: 31090209 PMCID: PMC7065082 DOI: 10.1002/ar.24148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/23/2018] [Accepted: 09/07/2018] [Indexed: 11/25/2022]
Abstract
The auditory apparatus of the inner ear does not show turnover of sensory hair cells (HCs) in adult mammals; in contrast, there are many observations supporting low‐level turnover of vestibular HCs within the balance organs of mammalian inner ears. This low‐level renewal of vestibular HCs exists during normal conditions and it is further enhanced after trauma‐induced loss of these HCs. The main process for renewal of HCs within mammalian vestibular epithelia is a conversion/transdifferentiation of existing supporting cells (SCs) into replacement HCs.In earlier studies using long‐term organ cultures of postnatal rat macula utriculi, HC loss induced by gentamicin resulted in an initial substantial decline in HC density followed by a significant increase in the proportion of HCs to SCs indicating the production of replacement HCs. In the present study, using the same model of ototoxic damage to study renewal of vestibular HCs, we focus on the ultrastructural characteristics of SCs undergoing transdifferentiation into new HCs. Our objective was to search for morphological signs of SC plasticity during this process. In the utricular epithelia, we observed immature HCs, which appear to be SCs transdifferentiating into HCs. These bridge SCs have unique morphological features characterized by formation of foot processes, basal accumulation of mitochondria, and an increased amount of connections with nearby SCs. No gap junctions were observed on these transitional cells. The tight junction seals were morphologically intact in both control and gentamicin‐exposed explants. Anat Rec, 303:506–515, 2020. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.
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Affiliation(s)
- Mimmi Werner
- Department of Clinical Sciences, Otolaryngology, University of Umeå, Umeå, Sweden
| | - Thomas R Van De Water
- Cochlear Implant Research Program, Department of Otolaryngology, University of Miami Ear Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Hans Stenlund
- Department of Epidemiology and Global Health, University of Umeå, Umeå, Sweden
| | - Diana Berggren
- Department of Clinical Sciences, Otolaryngology, University of Umeå, Umeå, Sweden
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Necroptosis and Apoptosis Contribute to Cisplatin and Aminoglycoside Ototoxicity. J Neurosci 2019; 39:2951-2964. [PMID: 30733218 DOI: 10.1523/jneurosci.1384-18.2019] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 01/23/2019] [Accepted: 01/30/2019] [Indexed: 11/21/2022] Open
Abstract
Ototoxic side effects of cisplatin and aminoglycosides have been extensively studied, but no therapy is available to date. Sensory hair cells, upon exposure to cisplatin or aminoglycosides, undergo apoptotic and necrotic cell death. Blocking these cell death pathways has therapeutic potential in theory, but incomplete protection and lack of therapeutic targets in the case of necrosis, has hampered the development of clinically applicable drugs. Over the past decade, a novel form of necrosis, termed necroptosis, was established as an alternative cell death pathway. Necroptosis is distinguished from passive necrotic cell death, in that it follows a cellular program, involving the receptor-interacting protein kinase (RIPK) 1 and RIPK3. In this study, we used pharmacological and genetic interventions in the mouse to test the relative contributions of necroptosis and caspase-8-mediated apoptosis toward cisplatin and aminoglycoside ototoxicity. We find that ex vivo, only apoptosis contributes to cisplatin and aminoglycoside ototoxicity, while in vivo, necroptosis as well as apoptosis are involved in both sexes. Inhibition of necroptosis and apoptosis using pharmacological compounds is thus a viable strategy to ameliorate aminoglycoside and cisplatin ototoxicity.SIGNIFICANCE STATEMENT The clinical application of cisplatin and aminoglycosides is limited due to ototoxic side effects. Here, using pharmaceutical and genetic intervention, we present evidence that two types of programmed cell death, apoptosis and necroptosis, contribute to aminoglycoside and cisplatin ototoxicity. Key molecular factors mediating necroptosis are well characterized and druggable, presenting new avenues for pharmaceutical intervention.
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19
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Pasireotide protects mammalian cochlear hair cells from gentamicin ototoxicity by activating the PI3K-Akt pathway. Cell Death Dis 2019; 10:110. [PMID: 30728348 PMCID: PMC6365508 DOI: 10.1038/s41419-019-1386-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/18/2018] [Accepted: 01/15/2019] [Indexed: 01/07/2023]
Abstract
Gentamicin is a widely used antibiotic for the treatment of gram-negative bacterial infections; however, its use often results in significant and permanent hearing loss. Hearing loss resulting from hair cell (HC) degeneration affects millions of people worldwide, and one major cause is the loss of sensory HCs in the inner ear due to aminoglycoside exposure. Strategies to overcome the apparently irreversible loss of HCs in mammals are crucial for hearing protection. Here, we report that the somatostatin analog pasireotide protects mouse cochlear HCs from gentamicin damage using a well-established in vitro gentamicin-induced HC loss model and that the otoprotective effects of pasireotide are due to Akt up-regulation via the PI3K–Akt signal pathway activation. We demonstrate active caspase signal in organ of Corti (OC) explants exposed to gentamicin and show that pasireotide treatment activates survival genes, reduces caspase signal, and increases HC survival. The neuropeptide somatostatin and its selective analogs have provided neuroprotection by activating five somatostatin receptor (SSTR1–SSTR5) subtypes. Pasireotide has a high affinity for SSTR2 and SSTR5, and the addition of SSTR2- and SSTR5-specific antagonists leads to a loss of protection. The otoprotective effects of pasireotide were also observed in a gentamicin-injured animal model. In vivo studies have shown that 13 days of subcutaneous pasireotide application prevents gentamicin-induced HC death and permanent hearing loss in mice. Auditory brainstem response analysis confirmed the protective effect of pasireotide, and we found a significant threshold shift at all measured frequencies (4, 8, 16, 24, and 32 kHz). Together, these findings indicate that pasireotide is a novel otoprotective peptide acting via the PI3K–Akt pathway and may be of therapeutic value for HC protection from ototoxic insults.
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20
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Therapeutic and protective effects of autologous serum in amikacin-induced ototoxicity. The Journal of Laryngology & Otology 2017; 132:33-40. [PMID: 29151378 DOI: 10.1017/s0022215117002304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Possible therapeutic and protective benefits of intratympanic autologous serum application in amikacin-induced ototoxicity were investigated. METHODS Twenty-four guinea pigs were separated equally into two groups: therapeutic (group A) and protective (group B). Transient evoked otoacoustic emissions were recorded before and after autologous serum application. Apoptotic cells were identified in the organ of Corti, spiral limbus and spiral ganglion by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling ('TUNEL') method. RESULTS Transient evoked otoacoustic emission responses at 1, 1.4 and 2.8 kHz improved without significance after autologous serum application in group A (p > 0.05). A significantly protective effect of autologous serum was determined at 4 kHz in group B (p < 0.05). There were significantly fewer apoptotic cells at the spiral limbus in the therapeutic and protective groups compared to the control group (p < 0.05). CONCLUSION Autologous serum may offer protection against ototoxicity-induced hearing loss, but it cannot restore hearing. Immunohistochemically, autologous serum significantly decreases activation of the intrinsic pathway of pro-apoptotic signalling in mesenchymal cells compared to neurons and neurosensory cells.
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21
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Sultemeier DR, Hoffman LF. Partial Aminoglycoside Lesions in Vestibular Epithelia Reveal Broad Sensory Dysfunction Associated with Modest Hair Cell Loss and Afferent Calyx Retraction. Front Cell Neurosci 2017; 11:331. [PMID: 29163044 PMCID: PMC5663721 DOI: 10.3389/fncel.2017.00331] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/09/2017] [Indexed: 11/13/2022] Open
Abstract
Although the effects of aminoglycoside antibiotics on hair cells have been investigated for decades, their influences on the dendrites of primary afferent neurons have not been widely studied. This is undoubtedly due to the difficulty in disassociating pathology to dendritic processes from that resulting from loss of the presynaptic hair cell. This was overcome in the present investigation through development of a preparation using Chinchilla laniger that enabled direct perilymphatic infusion. Through this strategy we unmasked gentamicin's potential effects on afferent calyces. The pathophysiology of the vestibular neuroepithelia after post-administration durations of 0.5 through 6 months was assessed using single-neuron electrophysiology, immunohistochemistry, and confocal microscopy. Hair cell densities within cristae central zones (0.5-, 1-, 2-, and 6-months) and utricle peri- and extrastriola (6-months) regions were determined, and damage to calretinin-immunoreactive calyces was quantified. Gentamicin-induced hair cell loss exhibited a profile that reflected elimination of a most-sensitive group by 0.5-months post-administration (18.2%), followed by loss of a second group (20.6%) over the subsequent 5.5 months. The total hair cell loss with this gentamicin dose (approximately 38.8%) was less than the estimated fraction of type I hair cells in the chinchilla's crista central zone (approximately 60%), indicating that viable type I hair cells remained. Extensive lesions to afferent calyces were observed at 0.5-months, though stimulus-evoked modulation was intact at this post-administration time. Widespread compromise to calyx morphology and severe attenuation of stimulus-evoked afferent discharge modulation was found at 1 month post-administration, a condition that persisted in preparations examined through the 6-month post-administration interval. Spontaneous discharge was robust at all post-administration intervals. All calretinin-positive calyces had retracted at 2 and 6 months post-administration. We found no evidence of morphologic or physiologic recovery. These results indicate that gentamicin-induced partial lesions to vestibular epithelia include hair cell loss (ostensibly reflecting an apoptotic effect) that is far less extensive than the compromise to stimulus-evoked afferent discharge modulation and retraction of afferent calyces (reflecting non-apoptotic effects). Additionally, calyx retraction cannot be completely accounted for by loss of type I hair cells, supporting the possibility for direct action of gentamicin on the afferent dendrite.
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Affiliation(s)
- David R. Sultemeier
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Larry F. Hoffman
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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22
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Ryals M, Pak K, Jalota R, Kurabi A, Ryan AF. A kinase inhibitor library screen identifies novel enzymes involved in ototoxic damage to the murine organ of Corti. PLoS One 2017; 12:e0186001. [PMID: 29049311 PMCID: PMC5648133 DOI: 10.1371/journal.pone.0186001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 09/22/2017] [Indexed: 11/25/2022] Open
Abstract
Ototoxicity is a significant side effect of a number of drugs, including the aminoglycoside antibiotics and platinum-based chemotherapeutic agents that are used to treat life-threatening illnesses. Although much progress has been made, the mechanisms that lead to ototoxic loss of inner ear sensory hair cells (HCs) remains incompletely understood. Given the critical role of protein phosphorylation in intracellular processes, including both damage and survival signaling, we screened a library of kinase inhibitors targeting members of all the major families in the kinome. Micro-explants from the organ of Corti of mice in which only the sensory cells express GFP were exposed to 200 μM of the ototoxic aminoglycoside gentamicin with or without three dosages of each kinase inhibitor. The loss of sensory cells was compared to that seen with gentamicin alone, or without treatment. Of the 160 inhibitors, 15 exhibited a statistically significant protective effect, while 3 significantly enhanced HC loss. The results confirm some previous studies of kinase involvement in HC damage and survival, and also highlight several novel potential kinase pathway contributions to ototoxicity.
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Affiliation(s)
- Matthew Ryals
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Kwang Pak
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Rahul Jalota
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Arwa Kurabi
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Allen F. Ryan
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
- Research Service, Veterans Administration Medical Center, San Diego, California, United States of America
- * E-mail:
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23
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Wiedenhoft H, Hayashi L, Coffin AB. PI3K and Inhibitor of Apoptosis Proteins Modulate Gentamicin- Induced Hair Cell Death in the Zebrafish Lateral Line. Front Cell Neurosci 2017; 11:326. [PMID: 29093665 PMCID: PMC5651234 DOI: 10.3389/fncel.2017.00326] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/03/2017] [Indexed: 12/16/2022] Open
Abstract
Inner ear hair cell death leads to sensorineural hearing loss and can be a direct consequence of aminoglycoside antibiotic treatment. Aminoglycosides such as gentamicin are effective therapy for serious Gram-negative bacterial infections such as some forms of meningitis, pneumonia, and sepsis. Aminoglycosides enter hair cells through mechanotransduction channels at the apical end of hair bundles and initiate intrinsic cell death cascades, but the precise cell signaling that leads to hair cell death is incompletely understood. Here, we examine the cell death pathways involved in aminoglycoside damage using the zebrafish (Danio rerio). The zebrafish lateral line contains hair cell-bearing organs called neuromasts that are homologous to hair cells of the mammalian inner ear and represents an excellent model to study ototoxicity. Based on previous research demonstrating a role for p53, Bcl2 signaling, autophagy, and proteasomal degradation in aminoglycoside-damaged hair cells, we used the Cytoscape GeneMANIA Database to identify additional proteins that might play a role in neomycin or gentamicin ototoxicity. Our bioinformatics analysis identified the pro-survival proteins phosphoinositide-dependent kinase-1 (PDK1) and X-linked inhibitor of apoptosis protein (Xiap) as potential mediators of gentamicin-induced hair cell damage. Pharmacological inhibition of PDK1 or its downstream mediator protein kinase C facilitated gentamicin toxicity, as did Xiap mutation, suggesting that both PI3K and endogenous Xiap confer protection. Surprisingly, aminoglycoside-induced hair cell death was highly attenuated in wild type Tupfel long-fin (TL fish; the background strain for the Xiap mutant line) compared to wild type ∗AB zebrafish. Pharmacologic manipulation of p53 suggested that the strain difference might result from decreased p53 in TL hair cells, allowing for increased hair cell survival. Overall, our studies identified additional steps in the cell death cascade triggered by aminoglycoside damage, suggesting possible drug targets to combat hearing loss resulting from aminoglycoside exposure.
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Affiliation(s)
- Heather Wiedenhoft
- College of Arts and Sciences, Washington State University, Vancouver, WA, United States
| | - Lauren Hayashi
- Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States
| | - Allison B Coffin
- College of Arts and Sciences, Washington State University, Vancouver, WA, United States.,Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, WA, United States
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24
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Kirkwood NK, O'Reilly M, Derudas M, Kenyon EJ, Huckvale R, van Netten SM, Ward SE, Richardson GP, Kros CJ. d-Tubocurarine and Berbamine: Alkaloids That Are Permeant Blockers of the Hair Cell's Mechano-Electrical Transducer Channel and Protect from Aminoglycoside Toxicity. Front Cell Neurosci 2017; 11:262. [PMID: 28928635 PMCID: PMC5591855 DOI: 10.3389/fncel.2017.00262] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/14/2017] [Indexed: 12/03/2022] Open
Abstract
Aminoglycoside antibiotics are widely used for the treatment of life-threatening bacterial infections, but cause permanent hearing loss in a substantial proportion of treated patients. The sensory hair cells of the inner ear are damaged following entry of these antibiotics via the mechano-electrical transducer (MET) channels located at the tips of the hair cell's stereocilia. d-Tubocurarine (dTC) is a MET channel blocker that reduces the loading of gentamicin-Texas Red (GTTR) into rat cochlear hair cells and protects them from gentamicin treatment. Berbamine is a structurally related alkaloid that reduces GTTR labeling of zebrafish lateral-line hair cells and protects them from aminoglycoside-induced cell death. Both compounds are thought to reduce aminoglycoside entry into hair cells through the MET channels. Here we show that dTC (≥6.25 μM) or berbamine (≥1.55 μM) protect zebrafish hair cells in vivo from neomycin (6.25 μM, 1 h). Protection of zebrafish hair cells against gentamicin (10 μM, 6 h) was provided by ≥25 μM dTC or ≥12.5 μM berbamine. Hair cells in mouse cochlear cultures are protected from longer-term exposure to gentamicin (5 μM, 48 h) by 20 μM berbamine or 25 μM dTC. Berbamine is, however, highly toxic to mouse cochlear hair cells at higher concentrations (≥30 μM) whilst dTC is not. The absence of toxicity in the zebrafish assays prompts caution in extrapolating results from zebrafish neuromasts to mammalian cochlear hair cells. MET current recordings from mouse outer hair cells (OHCs) show that both compounds are permeant open-channel blockers, rapidly and reversibly blocking the MET channel with half-blocking concentrations of 2.2 μM (dTC) and 2.8 μM (berbamine) in the presence of 1.3 mM Ca2+ at −104 mV. Berbamine, but not dTC, also blocks the hair cell's basolateral K+ current, IK,neo, and modeling studies indicate that berbamine permeates the MET channel more readily than dTC. These studies reveal key properties of MET-channel blockers required for the future design of successful otoprotectants.
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Affiliation(s)
- Nerissa K Kirkwood
- Sussex Neuroscience, School of Life Sciences, University of SussexBrighton, United Kingdom
| | - Molly O'Reilly
- Sussex Neuroscience, School of Life Sciences, University of SussexBrighton, United Kingdom
| | - Marco Derudas
- Sussex Drug Discovery Centre, School of Life Sciences, University of SussexBrighton, United Kingdom
| | - Emma J Kenyon
- Sussex Neuroscience, School of Life Sciences, University of SussexBrighton, United Kingdom
| | - Rosemary Huckvale
- Sussex Drug Discovery Centre, School of Life Sciences, University of SussexBrighton, United Kingdom
| | - Sietse M van Netten
- Institute of Artificial Intelligence and Cognitive Engineering, University of GroningenGroningen, Netherlands
| | - Simon E Ward
- Sussex Drug Discovery Centre, School of Life Sciences, University of SussexBrighton, United Kingdom
| | - Guy P Richardson
- Sussex Neuroscience, School of Life Sciences, University of SussexBrighton, United Kingdom
| | - Corné J Kros
- Sussex Neuroscience, School of Life Sciences, University of SussexBrighton, United Kingdom
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25
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Reduction of permanent hearing loss by local glucocorticoid application : Guinea pigs with acute acoustic trauma. HNO 2017; 65:59-67. [PMID: 27878601 DOI: 10.1007/s00106-016-0266-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND High-intensity noise exposure from impulse and blast noise events often leads to acute hearing loss and may cause irreversible permanent hearing loss as a long-term consequence. Here, a treatment regime was developed to limit permanent damage based on a preclinical animal model of acute noise trauma. AIM To develop clinical trials for the treatment of acute noise traumas using approved drugs. The otoprotective potential of glucocorticoids applied locally to the inner ear was examined. MATERIALS AND METHODS A series of experiments with different impulse noise exposures were performed. Permanent hearing loss and hair cell density were assessed 14 days after exposure. Hearing and hair cell preservation were investigated as a function of the glucocorticoid dose. RESULTS After impulse noise exposure, local application to the round window of the cochlea of high-dose prednisolone (25 mg/ml) or methylprednisolone (12.5 mg/ml) resulted in a statistically significant reduction in hearing loss compared with the control group. CONCLUSION The local application of high doses of the drugs to the round window of the cochlea appears to be an effective treatment for acute noise trauma.
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Diphtheria Toxin-Induced Cell Death Triggers Wnt-Dependent Hair Cell Regeneration in Neonatal Mice. J Neurosci 2017; 36:9479-89. [PMID: 27605621 DOI: 10.1523/jneurosci.2447-15.2016] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 07/20/2016] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED Cochlear hair cells (HCs), the sensory cells that respond to sound, do not regenerate after damage in adult mammals, and their loss is a major cause of deafness. Here we show that HC regeneration in newborn mouse ears occurred spontaneously when the original cells were ablated by treatment with diphtheria toxin (DT) in ears that had been engineered to overexpress the DT receptor, but was not detectable when HCs were ablated in vivo by the aminoglycoside antibiotic neomycin. A variety of Wnts (Wnt1, Wnt2, Wnt2b, Wnt4, Wnt5a, Wnt7b, Wnt9a, Wnt9b, and Wnt11) and Wnt pathway component Krm2 were upregulated after DT damage. Nuclear β-catenin was upregulated in HCs and supporting cells of the DT-damaged cochlea. Pharmacological inhibition of Wnt decreased spontaneous regeneration, confirming a role of Wnt signaling in HC regeneration. Inhibition of Notch signaling further potentiated supporting cell proliferation and HC differentiation that occurred spontaneously. The absence of new HCs in the neomycin ears was correlated to less robust Wnt pathway activation, but the ears subjected to neomycin treatment nonetheless showed increased cell division and HC differentiation after subsequent forced upregulation of β-catenin. These studies suggest, first, that Wnt signaling plays a key role in regeneration, and, second, that the outcome of a regenerative response to damage in the newborn cochlea is determined by reaching a threshold level of Wnt signaling rather than its complete absence or presence. SIGNIFICANCE STATEMENT Sensory HCs of the inner ear do not regenerate in the adult, and their loss is a major cause of deafness. We found that HCs regenerated spontaneously in the newborn mouse after diphtheria toxin (DT)-induced, but not neomycin-induced, HC death. Regeneration depended on activation of Wnt signaling, and regeneration in DT-treated ears correlated to a higher level of Wnt activation than occurred in nonregenerating neomycin-treated ears. This is significant because insufficient regeneration caused by a failure to reach a threshold level of signaling, if true in the adult, has the potential to be exploited for development of clinical approaches for the treatment of deafness caused by HC loss.
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Ma X, Liu Y, Muhammad W, Liu D, Wang J, Zhou H, Gao X, Qian X. Autophagy-related protein 12 associates with anti-apoptotic B cell lymphoma-2 to promote apoptosis in gentamicin-induced inner ear hair cell loss. Mol Med Rep 2017; 15:3819-3825. [PMID: 28440437 DOI: 10.3892/mmr.2017.6458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 02/15/2017] [Indexed: 11/05/2022] Open
Abstract
The aim of the present study was to investigate the underlying mechanisms of autophagy in a gentamicin (GM)-induced ototoxic model, and to establish whether the blocking of autophagy significantly increases the survival of inner ear hair cells. Cochleae were carefully dissected from four day‑old C57BL/6J mice and randomly divided into three groups prior to explant culture: Control (culture medium), GM‑treated (culture medium + GM) and GM + 3-methyladenine (3-MA; culture medium + GM + 3‑MA). Transmission electron microscopy, immunofluorescence and western blotting were performed to observe the expression of the autophagy protein microtubule‑associated protein 1A/B‑light chain 3 in explant cultures treated with GM and the autophagy inhibitor 3‑MA. Administration of GM in in vitro mouse cochlear culture induced apoptosis and the formation of autophagic vesicles and autophagosomes in hair cells. Notably, combined treatment with GM and 3‑MA to block autophagy significantly increased the survival of inner ear hair cells. Furthermore, it was indicated that the simultaneous expression and interaction of Atg12 with Bcl‑2 following GM treatment co‑integrated autophagy with apoptosis in the cochlea. The results of the present study demonstrated that autophagy was involved in GM-induced ototoxicity. Additionally, Atg12 may serve a protective role by binding to Bcl‑2. Therefore, Atg12 may be a potential therapeutic target for the treatment of GM-induced cochlear hair loss.
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Affiliation(s)
- Xiaofeng Ma
- Department of Otorhinolaryngology‑Head and Neck Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Yongze Liu
- Department of Otorhinolaryngology‑Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, Jiangsu 210008, P.R. China
| | - Waqas Muhammad
- State Key Laboratory of Bioelectronics, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu 210096, P.R. China
| | - Dingding Liu
- Department of Otorhinolaryngology‑Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, Jiangsu 210008, P.R. China
| | - Junguo Wang
- Department of Otorhinolaryngology‑Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, Jiangsu 210008, P.R. China
| | - Han Zhou
- Department of Otorhinolaryngology‑Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, Jiangsu 210008, P.R. China
| | - Xia Gao
- Department of Otorhinolaryngology‑Head and Neck Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, Jiangsu 210008, P.R. China
| | - Xiaoyun Qian
- Department of Otorhinolaryngology‑Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, Jiangsu 210008, P.R. China
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Park C, Ji HM, Kim SJ, Kil SH, Lee JN, Kwak S, Choe SK, Park R. Fenofibrate exerts protective effects against gentamicin-induced toxicity in cochlear hair cells by activating antioxidant enzymes. Int J Mol Med 2017; 39:960-968. [PMID: 28290603 PMCID: PMC5360428 DOI: 10.3892/ijmm.2017.2916] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 02/24/2017] [Indexed: 12/19/2022] Open
Abstract
Fenofibrate, an activator of peroxisome proliferator-activated receptors (PPARs), has been shown to protect the kidneys and brain cells from oxidative stress; however, its role in preventing hearing loss has not been reported to date, at least to the best of our knowledge. In this study, we demonstrated the protective effects of fenofibrate against gentamicin (GM)-induced ototoxicity. We found that the auditory brainstem response threshold which was increased by GM was significantly reduced by pre-treatment with fenofibrate in rats. In cochlear explants, the disruption of hair cell layers by GM was also markedly attenuated by pre-treatment with fenofibrate. In addition, fenofibrate almost completely abolished GM-induced reactive oxygen species generation, which seemed to be mediated at least in part by the restoration of the expression of PPAR-α-dependent antioxidant enzymes, including catalase and superoxide dismutase (SOD)-1. Of note, fenofibrate markedly increased the expression of heme oxygenase-1 (HO-1) which was also induced to a certain degree by GM alone. The induced expression of HO-1 by fenofibrate appeared to be essential for mediating the protective effects of fenofibrate, as the inhibition of HO-1 activity significantly diminished the protective effects of fenofibrate against the GM-mediated death of sensory hair cells in cochlea explant culture, as well as in zebrafish neuromasts. These results suggest that fenofibrate protects sensory hair cells from GM-induced toxicity by upregulating PPAR-α-dependent antioxidant enzymes, including HO-1. Our results provide insight into the preventive therapy for hearing loss caused by aminoglycoside antibiotics.
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Affiliation(s)
- Channy Park
- Department of Microbiology and Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk 54538, Republic of Korea
| | - Hye-Min Ji
- Department of Microbiology and Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk 54538, Republic of Korea
| | - Se-Jin Kim
- Department of Microbiology and Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk 54538, Republic of Korea
| | - Sung-Hee Kil
- Division of Cell Biology and Genetics, House Research Institute, Los Angeles, CA 90057, USA
| | - Joon No Lee
- Department of Microbiology and Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk 54538, Republic of Korea
| | - Seongae Kwak
- Zoonosis Research Center, Wonkwang University School of Medicine, Iksan, Jeonbuk 54538, Republic of Korea
| | - Seong-Kyu Choe
- Department of Microbiology and Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk 54538, Republic of Korea
| | - Raekil Park
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
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Bucks SA, Cox BC, Vlosich BA, Manning JP, Nguyen TB, Stone JS. Supporting cells remove and replace sensory receptor hair cells in a balance organ of adult mice. eLife 2017; 6:e18128. [PMID: 28263708 PMCID: PMC5338920 DOI: 10.7554/elife.18128] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 01/20/2017] [Indexed: 01/20/2023] Open
Abstract
Vestibular hair cells in the inner ear encode head movements and mediate the sense of balance. These cells undergo cell death and replacement (turnover) throughout life in non-mammalian vertebrates. However, there is no definitive evidence that this process occurs in mammals. We used fate-mapping and other methods to demonstrate that utricular type II vestibular hair cells undergo turnover in adult mice under normal conditions. We found that supporting cells phagocytose both type I and II hair cells. Plp1-CreERT2-expressing supporting cells replace type II hair cells. Type I hair cells are not restored by Plp1-CreERT2-expressing supporting cells or by Atoh1-CreERTM-expressing type II hair cells. Destruction of hair cells causes supporting cells to generate 6 times as many type II hair cells compared to normal conditions. These findings expand our understanding of sensorineural plasticity in adult vestibular organs and further elucidate the roles that supporting cells serve during homeostasis and after injury.
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Affiliation(s)
- Stephanie A Bucks
- Department of Otolaryngology-Head and Neck Surgery, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, United States
| | - Brandon C Cox
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, United States,Department of Surgery, Division of Otolaryngology, Southern Illinois University School of Medicine, Springfield, United States
| | - Brittany A Vlosich
- Department of Otolaryngology-Head and Neck Surgery, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, United States
| | - James P Manning
- Department of Otolaryngology-Head and Neck Surgery, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, United States
| | - Tot B Nguyen
- Department of Otolaryngology-Head and Neck Surgery, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, United States
| | - Jennifer S Stone
- Department of Otolaryngology-Head and Neck Surgery, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, United States,
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Müller M, Tisch M, Maier H, Löwenheim H. Begrenzung chronischer Hörverluste durch lokale Glukokortikoidgabe. HNO 2016; 64:831-840. [DOI: 10.1007/s00106-016-0256-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Kruger M, Boney R, Ordoobadi AJ, Sommers TF, Trapani JG, Coffin AB. Natural Bizbenzoquinoline Derivatives Protect Zebrafish Lateral Line Sensory Hair Cells from Aminoglycoside Toxicity. Front Cell Neurosci 2016; 10:83. [PMID: 27065807 PMCID: PMC4811916 DOI: 10.3389/fncel.2016.00083] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 03/16/2016] [Indexed: 01/24/2023] Open
Abstract
Moderate to severe hearing loss affects 360 million people worldwide and most often results from damage to sensory hair cells. Hair cell damage can result from aging, genetic mutations, excess noise exposure, and certain medications including aminoglycoside antibiotics. Aminoglycosides are effective at treating infections associated with cystic fibrosis and other life-threatening conditions such as sepsis, but cause hearing loss in 20–30% of patients. It is therefore imperative to develop new therapies to combat hearing loss and allow safe use of these potent antibiotics. We approach this drug discovery question using the larval zebrafish lateral line because zebrafish hair cells are structurally and functionally similar to mammalian inner ear hair cells and respond similarly to toxins. We screened a library of 502 natural compounds in order to identify novel hair cell protectants. Our screen identified four bisbenzylisoquinoline derivatives: berbamine, E6 berbamine, hernandezine, and isotetrandrine, each of which robustly protected hair cells from aminoglycoside-induced damage. Using fluorescence microscopy and electrophysiology, we demonstrated that the natural compounds confer protection by reducing antibiotic uptake into hair cells and showed that hair cells remain functional during and after incubation in E6 berbamine. We also determined that these natural compounds do not reduce antibiotic efficacy. Together, these natural compounds represent a novel source of possible otoprotective drugs that may offer therapeutic options for patients receiving aminoglycoside treatment.
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Affiliation(s)
- Matthew Kruger
- School of Biological Sciences, Washington State University Vancouver, WA, USA
| | - Robert Boney
- College of Arts and Sciences, Washington State University Vancouver, WA, USA
| | | | - Thomas F Sommers
- Department of Biology and Neuroscience Program, Amherst College Amherst, MA, USA
| | - Josef G Trapani
- Department of Biology and Neuroscience Program, Amherst College Amherst, MA, USA
| | - Allison B Coffin
- School of Biological Sciences, Washington State UniversityVancouver, WA, USA; College of Arts and Sciences, Washington State UniversityVancouver, WA, USA; Department of Integrative Physiology and Neuroscience, Washington State UniversityVancouver, WA, USA
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Chemical Ototoxicity of the Fish Inner Ear and Lateral Line. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 877:419-37. [PMID: 26515324 DOI: 10.1007/978-3-319-21059-9_18] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hair cell-driven mechanosensory systems are crucial for successful execution of a number of behaviors in fishes, and have emerged as good models for exploring questions relevant to human hearing. This review focuses on ototoxic effects in the inner ear and lateral line system of fishes. We specifically examine studies where chemical ototoxins such as aminoglycoside antibiotics have been employed as tools to disable the lateral line. Lateral line ablation results in alterations to feeding behavior and orientation to water current in a variety of species. However, neither behavior is abolished in the presence of additional sensory cues, supporting the hypothesis that many fish behaviors are driven by multisensory integration. Within biomedical research, the larval zebrafish lateral line has become an important model system for understanding signaling mechanisms that contribute to hair cell death and for developing novel pharmacological therapies that protect hair cells from ototoxic damage. Furthermore, given that fishes robustly regenerate damaged hair cells, ototoxin studies in fishes have broadened our understanding of the molecular and genetic events in an innately regenerative system, offering potential targets for mammalian hair cell regeneration. Collectively, studies of fish mechanosensory systems have yielded insight into fish behavior and in mechanisms of hair cell death, protection, and regeneration.
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Yamahara K, Yamamoto N, Nakagawa T, Ito J. Insulin-like growth factor 1: A novel treatment for the protection or regeneration of cochlear hair cells. Hear Res 2015; 330:2-9. [DOI: 10.1016/j.heares.2015.04.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 04/19/2015] [Accepted: 04/24/2015] [Indexed: 11/15/2022]
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Taylor RR, Jagger DJ, Saeed SR, Axon P, Donnelly N, Tysome J, Moffatt D, Irving R, Monksfield P, Coulson C, Freeman SR, Lloyd SK, Forge A. Characterizing human vestibular sensory epithelia for experimental studies: new hair bundles on old tissue and implications for therapeutic interventions in ageing. Neurobiol Aging 2015; 36:2068-84. [PMID: 25818177 PMCID: PMC4436436 DOI: 10.1016/j.neurobiolaging.2015.02.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 12/19/2022]
Abstract
Balance disequilibrium is a significant contributor to falls in the elderly. The most common cause of balance dysfunction is loss of sensory cells from the vestibular sensory epithelia of the inner ear. However, inaccessibility of inner ear tissue in humans severely restricts possibilities for experimental manipulation to develop therapies to ameliorate this loss. We provide a structural and functional analysis of human vestibular sensory epithelia harvested at trans-labyrinthine surgery. We demonstrate the viability of the tissue and labeling with specific markers of hair cell function and of ion homeostasis in the epithelium. Samples obtained from the oldest patients revealed a significant loss of hair cells across the tissue surface, but we found immature hair bundles present in epithelia harvested from patients >60 years of age. These results suggest that the environment of the human vestibular sensory epithelium could be responsive to stimulation of developmental pathways to enhance hair cell regeneration, as has been demonstrated successfully in the vestibular organs of adult mice.
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Affiliation(s)
| | | | - Shakeel R Saeed
- UCL Ear Institute, London, UK; Royal National Throat Nose and Ear Hospital, UCLH NHS Foundation Trust, London, UK
| | - Patrick Axon
- Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK
| | - Neil Donnelly
- Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK
| | - James Tysome
- Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK
| | - David Moffatt
- Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK
| | - Richard Irving
- Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Medical Centre, Birmingham, UK
| | - Peter Monksfield
- Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Medical Centre, Birmingham, UK
| | - Chris Coulson
- Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Medical Centre, Birmingham, UK
| | - Simon R Freeman
- Manchester Royal Infirmary, Central Manchester University Hospitals NHS Trust, Manchester, UK; Salford Royal Infirmary, Salford Royal NHS Foundation Trust, Salford, UK
| | - Simon K Lloyd
- Manchester Royal Infirmary, Central Manchester University Hospitals NHS Trust, Manchester, UK; Salford Royal Infirmary, Salford Royal NHS Foundation Trust, Salford, UK
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Tao L, Segil N. Early transcriptional response to aminoglycoside antibiotic suggests alternate pathways leading to apoptosis in sensory hair cells in the mouse inner ear. Front Cell Neurosci 2015; 9:190. [PMID: 26052268 PMCID: PMC4439550 DOI: 10.3389/fncel.2015.00190] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/29/2015] [Indexed: 01/22/2023] Open
Abstract
Aminoglycoside antibiotics are “the drug of choice” for treating many bacterial infections, but their administration results in hearing loss in up to one fourth of the patients who receive them. Several biochemical pathways have been implicated in aminoglycoside antibiotic ototoxicity; however, little is known about how hair cells respond to aminoglycoside antibiotics at the transcriptome level. Here we have investigated the genome-wide response to the aminoglycoside antibiotic gentamicin. Using organotypic cultures of the perinatal organ of Corti, we performed RNA sequencing using cDNA libraries obtained from FACS-purified hair cells. Within 3 h of gentamicin treatment, the messenger RNA level of more than three thousand genes in hair cells changed significantly. Bioinformatic analysis of these changes highlighted several known signal transduction pathways, including the JNK pathway and the NF-κB pathway, in addition to genes involved in the stress response, apoptosis, cell cycle control, and DNA damage repair. In contrast, only 698 genes, mainly involved in cell cycle and metabolite biosynthetic processes, were significantly affected in the non-hair cell population. The gene expression profiles of hair cells in response to gentamicin share a considerable similarity with those previously observed in gentamicin-induced nephrotoxicity. Our findings suggest that previously observed early responses to gentamicin in hair cells in specific signaling pathways are reflected in changes in gene expression. Additionally, the observed changes in gene expression of cell cycle regulatory genes indicate a disruption of the postmitotic state, which may suggest an alternate pathway regulating gentamicin-induced apoptotic hair cell death. This work provides a more comprehensive view of aminoglycoside antibiotic ototoxicity, and thus contributes to identifying potential pathways or therapeutic targets to alleviate this important side effect of aminoglycoside antibiotics.
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Affiliation(s)
- Litao Tao
- Genetic, Molecular and Cellular Biology Program, University of Southern California Los Angeles, CA, USA ; Department of Stem Cell Biology and Regenerative Medicine, University of Southern California Los Angeles, CA, USA
| | - Neil Segil
- Genetic, Molecular and Cellular Biology Program, University of Southern California Los Angeles, CA, USA ; Department of Stem Cell Biology and Regenerative Medicine, University of Southern California Los Angeles, CA, USA ; Department of Otolaryngology, University of Southern California Los Angeles, CA, USA
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Minocycline protection of neomycin induced hearing loss in gerbils. BIOMED RESEARCH INTERNATIONAL 2015; 2015:934158. [PMID: 25950003 PMCID: PMC4407513 DOI: 10.1155/2015/934158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 03/20/2015] [Accepted: 03/21/2015] [Indexed: 12/03/2022]
Abstract
This animal study was designed to determine if minocycline ameliorates cochlear damage is caused by intratympanic injection of the ototoxic aminoglycoside antibiotic neomycin. Baseline auditory-evoked brainstem responses were measured in gerbils that received 40 mM intratympanic neomycin either with 0, 1.2, or 1.5 mg/kg intraperitoneal minocycline. Four weeks later auditory-evoked brainstem responses were measured and compared to the baseline measurements. Minocycline treatments of 1.2 mg/kg and 1.5 mg/kg resulted in significantly lower threshold increases compared to 0 mg/kg, indicating protection of hearing loss between 6 kHz and 19 kHz. Cochleae were processed for histology and sectioned to allow quantification of the spiral ganglion neurons and histological evaluation of organ of Corti. Significant reduction of spiral ganglion neuron density was demonstrated in animals that did not receive minocycline, indicating that those receiving minocycline demonstrated enhanced survival of spiral ganglion neurons, enhanced survival of sensory hairs cells and spiral ganglion neurons, and reduced hearing threshold elevation correlates with minocycline treatment demonstrating that neomycin induced hearing loss can be reduced by the simultaneous application of minocycline.
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Cui C, Liu D, Qin X. Attenuation of Streptomycin Ototoxicity by Tetramethylpyrazine in Guinea Pig Cochlea. Otolaryngol Head Neck Surg 2015; 152:904-11. [PMID: 25605693 DOI: 10.1177/0194599814565594] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/04/2014] [Indexed: 01/17/2023]
Abstract
Objective Tetramethylpyrazine has been suggested to have a therapeutic effect on impaired hearing that is induced by aminoglycoside antibiotics. However, its effectiveness on streptomycin ototoxicity and its cellular mechanisms are relatively unknown. Here we investigate the protective effect of tetramethylpyrazine on streptomycin-induced ototoxicity in guinea pig cochlea. Study Design Prospective randomized laboratory study. Setting Hearing Research Laboratory of China Medical University. Subjects and Methods Adult guinea pigs were randomized to 4 groups. Hearing sensitivity of guinea pigs was tested by auditory brainstem response measurements before streptomycin exposure and again 10 days later. The cochlear tissues were prepared for electron microscopy and immunohistochemical staining of heat shock protein 70 (HSP70). The effect of tetramethylpyrazine on streptomycin-induced activation of caspase-3 was evaluated by Western blotting. Results Co-therapy with tetramethylpyrazine reduced a profound streptomycin-induced auditory threshold shift compared with streptomycin treatment alone ( P = .0002 or P = .00008). Tetramethylpyrazine also attenuated the structural disruption in streptomycin-treated outer hair cells and marginal cells of vascular stria by transmission electronic microscopy and scanning electronic microscopy, respectively. Moreover, tetramethylpyrazine decreased the streptomycin-stimulated expressions of HSP70 and caspase-3. The correlation analysis demonstrated that HSP70 expression had a positive correlation with auditory brainstem response thresholds (|R| = 0.6-0.9, P = .0073 or P = .0169). Conclusions Our data suggest that the protective effect of tetramethylpyrazine on hearing function is associated with the reduction of stress response and inhibition of apoptosis. Tetramethylpyrazine may have therapeutic potential for patients with ototoxicity diseases.
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Affiliation(s)
- Cheng Cui
- Hearing Research Laboratory, China Medical University, Shenyang, Liaoning, China
- Department of Physiology, China Medical University, Shenyang, Liaoning, China
| | - Dajun Liu
- Department of Nephrology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Xin Qin
- Department of Physiology, China Medical University, Shenyang, Liaoning, China
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Cannizzaro E, Cannizzaro C, Plescia F, Martines F, Soleo L, Pira E, Lo Coco D. Exposure to ototoxic agents and hearing loss: A review of current knowledge. HEARING BALANCE AND COMMUNICATION 2014. [DOI: 10.3109/21695717.2014.964939] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Sun S, Sun M, Zhang Y, Cheng C, Waqas M, Yu H, He Y, Xu B, Wang L, Wang J, Yin S, Chai R, Li H. In vivo overexpression of X-linked inhibitor of apoptosis protein protects against neomycin-induced hair cell loss in the apical turn of the cochlea during the ototoxic-sensitive period. Front Cell Neurosci 2014; 8:248. [PMID: 25278835 PMCID: PMC4166379 DOI: 10.3389/fncel.2014.00248] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 08/05/2014] [Indexed: 01/30/2023] Open
Abstract
Aminoglycoside-induced cochlear ototoxicity causes hair cell (HC) loss and results in hearing impairment in patients. Previous studies have developed the concept of an ototoxicity-sensitive period during which the cochleae of young mice are more vulnerable to auditory trauma than adults. Here, we compared neomycin-induced ototoxicity at the following four developmental ages in mice: postnatal day (P)1–P7, P8–P14, P15–P21, and P60–P66. We found that when neomycin was administered between P8 and P14, the auditory brainstem response threshold increase was significantly higher at low frequencies and HC loss was significantly greater in the apical turn of the cochlea compared to neomycin administration during the other age ranges. Quantitative real-time PCR (qPCR) data revealed that the expression of apoptotic markers, including Casp3 and Casp9, was significantly higher when neomycin was injected from P8 to P14, while the expression of the X-linked inhibitor of apoptosis protein (XIAP) gene was significantly higher when neomycin was injected from P60 to P66. Because XIAP expression was low during the neomycin-sensitive period, we overexpressed XIAP in mice and found that it could protect against neomycin-induced hearing loss at low frequencies and HC loss in the apical turn of the cochlea. Altogether, our findings demonstrate a protective role for XIAP against neomycin-induced hearing loss and HC loss in the apical turn of the cochlea during the ototoxic-sensitive period, and suggest that apoptotic factors mediate the effect of neomycin during the ototoxic-sensitive period.
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Affiliation(s)
- Shan Sun
- Research Center, Affiliated Eye and ENT Hospital of Fudan University Shanghai, China
| | - Mingzhi Sun
- Department of Otorhinolaryngology, Affiliated Eye and ENT Hospital of Fudan University Shanghai, China
| | - Yanping Zhang
- Research Center, Affiliated Eye and ENT Hospital of Fudan University Shanghai, China
| | - Cheng Cheng
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University Nanjing, China
| | - Muhammad Waqas
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University Nanjing, China
| | - Huiqian Yu
- Department of Otorhinolaryngology, Affiliated Eye and ENT Hospital of Fudan University Shanghai, China
| | - Yingzi He
- Research Center, Affiliated Eye and ENT Hospital of Fudan University Shanghai, China
| | - Bo Xu
- Anesthesiology Department, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Lei Wang
- Institute of Stem Cell and Regeneration Medicine, Institutions of Biomedical Science, Fudan University Shanghai, China ; State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University Shanghai, China
| | - Jian Wang
- Department of Otolaryngology, The Sixth Hospital Affiliated to Shanghai Jiao Tong University Shanghai, China
| | - Shankai Yin
- Department of Otolaryngology, The Sixth Hospital Affiliated to Shanghai Jiao Tong University Shanghai, China
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University Nanjing, China
| | - Huawei Li
- Department of Otorhinolaryngology, Affiliated Eye and ENT Hospital of Fudan University Shanghai, China ; Institute of Stem Cell and Regeneration Medicine, Institutions of Biomedical Science, Fudan University Shanghai, China ; State Key Laboratory of Medical Neurobiology, Fudan University Shanghai, China
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Protective effect of hexane and ethanol extract of piper longum L. On gentamicin-induced hair cell loss in neonatal cultures. Clin Exp Otorhinolaryngol 2014; 7:13-8. [PMID: 24587875 PMCID: PMC3932343 DOI: 10.3342/ceo.2014.7.1.13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 11/16/2012] [Accepted: 12/03/2012] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVES Gentamicin (GM) is a commonly used aminoglycoside antibiotic that generates free oxygen radicals within the inner ear, which can cause vestibulo-cochlear toxicity and permanent damage to the sensory hair cells and neurons. Piper longum L. (PL) is a well-known spice and traditional medicine in Asia and Pacific islands, which has been reported to exhibit a wide spectrum of activity, including antioxidant activity. In this study, we evaluated the effect of hexane:ethanol (2:8) PL extract (subfraction of PL [SPL] extract) on GM-induced hair cell loss in basal, middle and apical regions in a neonatal cochlea cultures. METHODS The protective effects of SPL extract were measured by phalloidin staining of cultures from postnatal day 2-3 mice with GM-induced hair cell loss. The anti-apoptosis activity of SPL extract was measured using double labeling by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and myosin-7a staining. The radical-scavenging activity of SPL extract was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. RESULTS SPL extract at a concentration of 1 µg/mL significantly inhibited GM-induced hair cell loss at basal and middle region of cochlea, while 5 µg/mL was effective against apical region hair cell loss. The protective effect of SPL extract was concentration dependent and hair cells retained their stereocilia in explants treated with SPL extract prior to treatment with 0.3 mM GM. SPL extract decreased GM-induced apoptosis of hair cells as assessed by TUNEL staining. The outer hair and inner hair counts were not decreased in SPL extract treated groups in compare to GM treated explants. Additionally, SPL extract showed concentration dependent radical scavenging activity in a DPPH assay. CONCLUSION An anti-apoptosis effect and potent radical scavenger activity of SPL extract protects from GM-induced hair cell loss at basal, middle and apical regions in neonatal cochlea cultures.
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Shi L, An Y, Wang A, Gao Q, Yang Y. The protective effect of Salvia miltiorrhiza on gentamicin-induced ototoxicity. Am J Otolaryngol 2014; 35:171-9. [PMID: 24119490 DOI: 10.1016/j.amjoto.2013.08.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 08/24/2013] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The clinical use of aminoglycoside antibiotics is limited in most countries because of auditory toxicity side effects. However, their use is common in developing countries because they are inexpensive and convenient. Salvia miltiorrhiza extracts are used clinically in China for their antioxidant properties. We investigated the effect of a clinically approved injectable S. miltiorrhiza solution on inducible nitric oxide synthase (iNOS) generation induced by the aminoglycoside antibiotic gentamicin and an ototoxicity protective mechanism. METHODS Sixty adult guinea pigs were used in this study and divided into four groups. Auditory brainstem response (ABR) testing was performed before and after treatments and animals were sacrificed for morphological and immunostaining assays after determining threshold shifts in ABR. The cochleae were examined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) to observe ultrastructural changes. In addition, hair cell loss, iNOS and caspase-3 expression, and apoptosis were measured. RESULTS The result showed that hearing loss, iNOS overexpression accompanied with disorganization in the cochlea, and terminal deoxynucleotidyl transferase- mediated dUTP- biotin nick end labeling (TUNEL)-stained positive cells in animals treated with gentamicin. However, pretreatment with S. miltiorrhiza (3g/kg/day for 10 days) decreased gentamicin-induced hearing loss, attenuated iNOS and caspase-3 expression, and decreased the number of apoptotic cells. Furthermore, it also reduced the ultrastructural damage due to ototoxicity as observed by SEM and TEM. CONCLUSIONS These findings indicate that S. miltiorrhiza protects against gentamicin-induced ototoxicity and could apply to the protection of ototoxicity.
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Affiliation(s)
- Lijuan Shi
- Department of Physiology, College of Basic Medical Sciences, China Medical University, Shenyang, China.
| | - Yuxiang An
- Department of Physiology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Aimei Wang
- Department of Physiology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Qinghua Gao
- Department of Physiology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Yu Yang
- Department of Physiology, College of Basic Medical Sciences, China Medical University, Shenyang, China
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Coffin AB, Williamson KL, Mamiya A, Raible DW, Rubel EW. Profiling drug-induced cell death pathways in the zebrafish lateral line. Apoptosis 2014; 18:393-408. [PMID: 23413197 DOI: 10.1007/s10495-013-0816-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Programmed cell death (PCD) is an important process in development and disease, as it allows the body to rid itself of unwanted or damaged cells. However, PCD pathways can also be activated in otherwise healthy cells. One such case occurs in sensory hair cells of the inner ear following exposure to ototoxic drugs, resulting in hearing loss and/or balance disorders. The intracellular pathways that determine if hair cells die or survive following this or other ototoxic challenges are incompletely understood. We use the larval zebrafish lateral line, an external hair cell-bearing sensory system, as a platform for profiling cell death pathways activated in response to ototoxic stimuli. In this report the importance of each pathway was assessed by screening a custom cell death inhibitor library for instances when pathway inhibition protected hair cells from the aminoglycosides neomycin or gentamicin, or the chemotherapy agent cisplatin. This screen revealed that each ototoxin likely activated a distinct subset of possible cell death pathways. For example, the proteasome inhibitor Z-LLF-CHO protected hair cells from either aminoglycoside or from cisplatin, while D-methionine, an antioxidant, protected hair cells from gentamicin or cisplatin but not from neomycin toxicity. The calpain inhibitor leupeptin primarily protected hair cells from neomycin, as did a Bax channel blocker. Neither caspase inhibition nor protein synthesis inhibition altered the progression of hair cell death. Taken together, these results suggest that ototoxin-treated hair cells die via multiple processes that form an interactive network of cell death signaling cascades.
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Affiliation(s)
- Allison B Coffin
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Box 357923, Seattle, WA 98195, USA.
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43
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Nakayama M, Tabuchi K, Hoshino T, Nakamagoe M, Nishimura B, Hara A. The influence of sphingosine-1-phosphate receptor antagonists on gentamicin-induced hair cell loss of the rat cochlea. Neurosci Lett 2014; 561:91-5. [PMID: 24397911 DOI: 10.1016/j.neulet.2013.12.063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 12/20/2013] [Accepted: 12/27/2013] [Indexed: 11/19/2022]
Abstract
Sphingosine-1-phosphate (S1P) is a sphingolipid metabolite that regulates various critical biological processes, such as cell proliferation, survival, migration, and angiogenesis. The action of S1P is exerted by its binding to 5 specific G protein-coupled S1P receptors (S1PR), S1PR1-S1PR5. Aminoglycoside antibiotics including gentamicin induce cochlear hair cell loss and sensorineural hearing loss. Apoptotic cell death is considered to play a key role in this type of cochlear injury. S1P acts as a cochlear protectant against gentamicin ototoxicity. In the present study, expression of S1PRs in the cochlea was examined. In addition, the effects of S1PR antagonists on gentamicin ototoxicity were investigated using tissue culture techniques. Cochleas were dissected from Sprague-Dawley rats on postnatal days 3-5. Basal turn organ of Corti explants were exposed to 35 μM gentamicin for 48 h with or without S1PR antagonists. S1PR(1-3) were expressed in the organ of Corti and spiral ganglion. The S1PR2 antagonist increased gentamicin-induced hair cell loss, while the S1PR1 and S1PR3 antagonists did not affect gentamicin ototoxicity. These results indicate the possibility that S1P act as a cochlear protectant against gentamicin ototoxicity via activation of S1PR2.
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Affiliation(s)
- Masahiro Nakayama
- Department of Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Keiji Tabuchi
- Department of Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
| | - Tomofumi Hoshino
- Department of Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Mariko Nakamagoe
- Department of Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Bungo Nishimura
- Department of Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Akira Hara
- Department of Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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Vestibular damage in chronic ototoxicity: a mini-review. Neurotoxicology 2013; 43:21-27. [PMID: 24333467 DOI: 10.1016/j.neuro.2013.11.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 11/28/2013] [Accepted: 11/28/2013] [Indexed: 01/26/2023]
Abstract
Ototoxicity is a major cause of the loss of hearing and balance in humans. Ototoxic compounds include pharmaceuticals such as aminoglycoside antibiotics, anti-malarial drugs, loop diuretics and chemotherapeutic platinum agents, and industrial chemicals including several solvents and nitriles. Human and rodent data indicate that the main target of toxicity is hair cells (HCs), which are the mechanosensory cells responsible for sensory transduction in both the auditory and the vestibular system. Nevertheless, the compounds may also affect the auditory and vestibular ganglion neurons. Exposure to ototoxic compounds has been found to cause HC apoptosis, HC necrosis, and damage to the afferent terminals, of differing severity depending on the ototoxicity model. One major pathway frequently involved in HC apoptosis is the c-jun N-terminal kinase (JNK) signaling pathway activated by reactive oxygen species, but other apoptotic pathways can also play a role in ototoxicity. Moreover, little is known about the effects of chronic low-dose exposure. In rodent vestibular epithelia, extrusion of live HCs from the sensory epithelium may be the predominant form of cell demise during chronic ototoxicity. In addition, greater involvement of the afferent terminals may occur, particularly the calyx units contacting type I vestibular HCs. As glutamate is the neurotransmitter in this synapse, excitotoxic phenomena may participate in afferent and ganglion neuron damage. Better knowledge of the events that take place in chronic ototoxicity is of great interest, as it will increase understanding of the sensory loss associated with chronic exposure and aging.
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45
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Golenser J, Domb A, Leshem B, Kremsner P, Luty A. Iron chelators as drugs against malaria pose a potential risk. Redox Rep 2013; 8:268-71. [PMID: 14962362 DOI: 10.1179/135100003225002880] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Affiliation(s)
- Jacob Golenser
- Department of Parasitology, The Hebrew University, Jerusalem, Israel.
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46
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Coffin AB, Rubel EW, Raible DW. Bax, Bcl2, and p53 differentially regulate neomycin- and gentamicin-induced hair cell death in the zebrafish lateral line. J Assoc Res Otolaryngol 2013; 14:645-59. [PMID: 23821348 DOI: 10.1007/s10162-013-0404-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 06/20/2013] [Indexed: 12/19/2022] Open
Abstract
Sensorineural hearing loss is a normal consequence of aging and results from a variety of extrinsic challenges such as excessive noise exposure and certain therapeutic drugs, including the aminoglycoside antibiotics. The proximal cause of hearing loss is often death of inner ear hair cells. The signaling pathways necessary for hair cell death are not fully understood and may be specific for each type of insult. In the lateral line, the closely related aminoglycoside antibiotics neomycin and gentamicin appear to kill hair cells by activating a partially overlapping suite of cell death pathways. The lateral line is a system of hair cell-containing sense organs found on the head and body of aquatic vertebrates. In the present study, we use a combination of pharmacologic and genetic manipulations to assess the contributions of p53, Bax, and Bcl2 in the death of zebrafish lateral line hair cells. Bax inhibition significantly protects hair cells from neomycin but not from gentamicin toxicity. Conversely, transgenic overexpression of Bcl2 attenuates hair cell death due to gentamicin but not neomycin, suggesting a complex interplay of pro-death and pro-survival proteins in drug-treated hair cells. p53 inhibition protects hair cells from damage due to either aminoglycoside, with more robust protection seen against gentamicin. Further experiments evaluating p53 suggest that inhibition of mitochondrial-specific p53 activity confers significant hair cell protection from either aminoglycoside. These results suggest a role for mitochondrial p53 activity in promoting hair cell death due to aminoglycosides, likely upstream of Bax and Bcl2.
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Affiliation(s)
- Allison B Coffin
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Box 357923, Seattle, WA, 98195, USA,
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Oesterle EC. Changes in the adult vertebrate auditory sensory epithelium after trauma. Hear Res 2013; 297:91-8. [PMID: 23178236 PMCID: PMC3637947 DOI: 10.1016/j.heares.2012.11.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 10/30/2012] [Accepted: 11/06/2012] [Indexed: 01/12/2023]
Abstract
Auditory hair cells transduce sound vibrations into membrane potential changes, ultimately leading to changes in neuronal firing and sound perception. This review provides an overview of the characteristics and repair capabilities of traumatized auditory sensory epithelium in the adult vertebrate ear. Injured mammalian auditory epithelium repairs itself by forming permanent scars but is unable to regenerate replacement hair cells. In contrast, injured non-mammalian vertebrate ear generates replacement hair cells to restore hearing functions. Non-sensory support cells within the auditory epithelium play key roles in the repair processes.
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Affiliation(s)
- Elizabeth C Oesterle
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, CHDD CD176, Box 357923, Univ. of Washington, Seattle, WA 98195-7923, USA.
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Esterberg R, Coffin AB, Ou H, Simon JA, Raible DW, Rubel EW. Fish in a Dish: Drug Discovery for Hearing Habilitation. ACTA ACUST UNITED AC 2013; 10. [PMID: 24187569 DOI: 10.1016/j.ddmod.2012.02.001] [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] [Indexed: 10/28/2022]
Abstract
The majority of hearing loss is caused by the permanent loss of inner ear hair cells. The identification of drugs that modulate the susceptibility to hair cell loss or spur their regeneration is often hampered by the difficulties of assaying for such complex phenomena in mammalian models. The zebrafish has emerged as a powerful animal model for chemical screening in many contexts. Several characteristics of the zebrafish, such as its small size and external location of sensory hair cells, uniquely position it as an ideal model organism for the study of hair cell toxicity, protection, and regeneration. We have used this model to screen for drugs that affect each of these aspects of hair cell biology and have identified compounds that affect each of these processes. The identification of such drugs and drug-like compounds holds promise in the future ability to stem hearing loss in the human population.
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Affiliation(s)
- Robert Esterberg
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington ; Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, Washington
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Eshraghi AA, Gupta C, Van De Water TR, Bohorquez JE, Garnham C, Bas E, Talamo VM. Molecular mechanisms involved in cochlear implantation trauma and the protection of hearing and auditory sensory cells by inhibition of c-jun-N-terminal kinase signaling. Laryngoscope 2013; 123 Suppl 1:S1-14. [DOI: 10.1002/lary.23902] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2012] [Indexed: 01/20/2023]
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50
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Eshraghi AA, Gupta C, Ozdamar O, Balkany TJ, Truy E, Nazarian R. Biomedical Engineering Principles of Modern Cochlear Implants and Recent Surgical Innovations. Anat Rec (Hoboken) 2012; 295:1957-66. [DOI: 10.1002/ar.22584] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 07/24/2012] [Indexed: 01/08/2023]
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