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Birru B, Veit JGS, Arrigali EM, Van Tine J, Barrett-Catton E, Tonnerre Z, Diaz P, Serban MA. Hyaluronic acid-ibuprofen conjugation: a novel ototherapeutic approach protecting inner ear cells from inflammation-mediated damage. Front Pharmacol 2024; 15:1355283. [PMID: 38425644 PMCID: PMC10902153 DOI: 10.3389/fphar.2024.1355283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/22/2024] [Indexed: 03/02/2024] Open
Abstract
There is a substantial need of effective drugs for the treatment of hearing loss, which affects nearly 500 million individuals globally. Hearing loss can be the result of intense or prolonged noise exposure, ototoxic drugs, infections, and trauma, which trigger inflammatory signaling cascades that lead to irreversible damage to cochlear structures. To address this, we developed and characterized a series of covalent conjugates of anti-inflammatory drugs to hyaluronic acid (HA), for potential use as topical ototherapeutics. These conjugates were tested in in vitro assays designed to mirror physiological processes typically observed with acoustic trauma. Intense noise exposure leads to macrophage recruitment to the cochlea and subsequent inflammatory damage to sensory cells. We therefore first tested our conjugates' ability to reduce the release of inflammatory cytokines in macrophages. This anti-inflammatory effect on macrophages also translated to increased cochlear cell viability. In our initial screening, one conjugate, ibuprofen-HA, demonstrated significantly higher anti-inflammatory potential than its counterparts. Subsequent cytokine release profiling of ibuprofen-HA further confirmed its ability to reduce a wider range of inflammatory markers, to a greater extent than its equivalent unconjugated drug. The conjugate's potential as a topical therapeutic was then assessed in previously developed tympanic and round window membrane tissue permeation models. As expected, our data indicate that the conjugate has limited tympanic membrane model permeability; however, it readily permeated the round window membrane model and to a greater extent than the unconjugated drug. Interestingly, our data also revealed that ibuprofen-HA was well tolerated in cellular and tissue cytocompatibility assays, whereas the unconjugated drug displayed significant cytotoxicity at equivalent concentrations. Moreover, our data highlighted the importance of chemical conjugation of ibuprofen to HA; the conjugate had improved anti-inflammatory effects, significantly reduced cytotoxicity, and is more suitable for therapeutic formulation. Overall, this work suggests that ibuprofen-HA could be a promising safe and effective topical ototherapeutic for inflammation-mediated cochlear damage.
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Affiliation(s)
- Bhaskar Birru
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
| | - Joachim G. S. Veit
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
- Montana Biotechnology Center (BIOTECH), University of Montana, Missoula, MT, United States
| | - Elizabeth M. Arrigali
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
| | - Jack Van Tine
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
| | - Emma Barrett-Catton
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
| | - Zachary Tonnerre
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
| | - Philippe Diaz
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
- Montana Biotechnology Center (BIOTECH), University of Montana, Missoula, MT, United States
| | - Monica A. Serban
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, United States
- Montana Biotechnology Center (BIOTECH), University of Montana, Missoula, MT, United States
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2
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Goodarzi Z, Khavanin A, Karami E, Rashidy-Pour A, Belji Kangarlou M, Kiani M, Razmjouei J. Otoprotective Effects of Quercetin Against Oxidative Damage in the Rat's Cochlea Induced by Noise and Silver Nanoparticles. Neuroscience 2023; 531:99-116. [PMID: 37714258 DOI: 10.1016/j.neuroscience.2023.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/01/2023] [Accepted: 09/07/2023] [Indexed: 09/17/2023]
Abstract
The aim of this study was to investigate the otoprotective effects of Quercetin (Que) against both noise-induced hearing loss (NIHL) and the ototoxicity of silver nanoparticles (SNPs) in rats. Forty-two male Wistar rats were divided into seven groups (n = 6): control, SNPs, Que (100 mg/kg) plus SNPs (100 mg/kg), noise (104 dB), Que plus noise, noise plus SNPs, and noise plus Que plus SNPs. In the weight change results, there was no significant difference between the groups exposed to noise plus SNPs and SNPs compared to the control group. However, animals had significant changes in DPOAE amplitude at 1 and 3 days post-exposure when compared to baseline. Additionally, the DPOAE value of rats administered with Que plus SNPs was higher than in all other groups. Que also decreased the levels of TACT, MDA, IL-6, TNF-α, and NOX3 in the groups exposed to noise and SNPs and increased the SOD level and expression of myosin heavy chain VII (MYH7) and β-tubulin III (TUBB3) proteins. Furthermore, Que decreased structural changes in the animals' cochlea. Our findings indicate that pretreatment with Que efficiently counteracted the adverse effects of noise and SNPs on inner hair cell, outer hair cell, and nerve cells, which are responsible for high-frequency perception.
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Affiliation(s)
- Zahra Goodarzi
- Department of Occupational Health Engineering, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Ali Khavanin
- Department of Occupational Health Engineering, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Esmaeil Karami
- Department of Occupational Health Engineering, School of Health, Tehran University of Medical Sciences, Tehran, Iran.
| | - Ali Rashidy-Pour
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran.
| | - Marzieh Belji Kangarlou
- Department of Occupational Health Engineering, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Mehrafarin Kiani
- Department of Anatomical Sciences, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Jaleh Razmjouei
- Masters of Health, Safety & Environment (HSE), Shahid Beheshti University of Medical Sciences and Health Services, Tehran, Iran.
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3
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Bazard P, Pineros J, Frisina RD, Bauer MA, Acosta AA, Paganella LR, Borakiewicz D, Thivierge M, Mannering FL, Zhu X, Ding B. Cochlear Inflammaging in Relation to Ion Channels and Mitochondrial Functions. Cells 2021; 10:2761. [PMID: 34685743 PMCID: PMC8534887 DOI: 10.3390/cells10102761] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/06/2021] [Accepted: 10/12/2021] [Indexed: 12/20/2022] Open
Abstract
The slow accumulation of inflammatory biomarker levels in the body-also known as inflammaging-has been linked to a myriad of age-related diseases. Some of these include neurodegenerative conditions such as Parkinson's disease, obesity, type II diabetes, cardiovascular disease, and many others. Though a direct correlation has not been established, research connecting age-related hearing loss (ARHL)-the number one communication disorder and one of the most prevalent neurodegenerative diseases of our aged population-and inflammaging has gained interest. Research, thus far, has found that inflammatory markers, such as IL-6 and white blood cells, are associated with ARHL in humans and animals. Moreover, studies investigating ion channels and mitochondrial involvement have shown promising relationships between their functions and inflammaging in the cochlea. In this review, we summarize key findings in inflammaging within the auditory system, the involvement of ion channels and mitochondrial functions, and lastly discuss potential treatment options focusing on controlling inflammation as we age.
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Affiliation(s)
- Parveen Bazard
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
| | - Jennifer Pineros
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
| | - Robert D. Frisina
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
- Department Communication Sciences and Disorders, College of Behavioral & Communication Sciences, Tampa, FL 33620, USA
- Morsani College of Medicine, University of South Florida, Tampa, FL 33620, USA
| | - Mark A. Bauer
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
| | - Alejandro A. Acosta
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
| | - Lauren R. Paganella
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
| | - Dominika Borakiewicz
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
| | - Mark Thivierge
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Morsani College of Medicine, University of South Florida, Tampa, FL 33620, USA
| | - Freyda L. Mannering
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
- Morsani College of Medicine, University of South Florida, Tampa, FL 33620, USA
| | - Xiaoxia Zhu
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
| | - Bo Ding
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (J.P.); (M.A.B.); (A.A.A.); (L.R.P.); (D.B.); (M.T.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA;
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Zhang Y, Li Y, Fu X, Wang P, Wang Q, Meng W, Wang T, Yang J, Chai R. The Detrimental and Beneficial Functions of Macrophages After Cochlear Injury. Front Cell Dev Biol 2021; 9:631904. [PMID: 34458249 PMCID: PMC8385413 DOI: 10.3389/fcell.2021.631904] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 07/14/2021] [Indexed: 12/20/2022] Open
Abstract
Macrophages are the main intrinsic immune cells in the cochlea; they can be activated and play a complicated role after cochlear injury. Many studies have shown that the number of macrophages and their morphological characteristics within the major cochlear partitions undergo significant changes under various pathological conditions including acoustic trauma, ototoxic drug treatment, age-related cochlear degeneration, selective hair cell (HC) and spiral ganglion neuron (SGN) elimination, and surgery. However, the exact role of these macrophages after cochlear injury is still unclear. Regulating the migration and activity of macrophages may be a therapeutic approach to reduce the risk or magnitude of trauma-induced hearing loss, and this review highlights the role of macrophages on the peripheral auditory structures of the cochlea and elucidate the mechanisms of macrophage injury and the strategies to reduce the injury by regulating macrophage.
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Affiliation(s)
- Yuan Zhang
- MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China.,Department of Otolaryngology Head and Neck, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yiyuan Li
- MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China
| | - Xiaolong Fu
- MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China
| | - Pengjun Wang
- Department of Otorhinolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Shanghai, China
| | - Qin Wang
- Department of Otolaryngology-Head and Neck Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Wei Meng
- Department of Otolaryngology Head and Neck, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Tian Wang
- Department of Otolaryngology-Head and Neck Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jianming Yang
- Department of Otorhinolaryngology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Renjie Chai
- MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
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5
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Noise-Induced Cochlear Damage Involves PPAR Down-Regulation through the Interplay between Oxidative Stress and Inflammation. Antioxidants (Basel) 2021; 10:antiox10081188. [PMID: 34439436 PMCID: PMC8388985 DOI: 10.3390/antiox10081188] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 12/14/2022] Open
Abstract
The cross-talk between oxidative stress and inflammation seems to play a key role in noise-induced hearing loss. Several studies have addressed the role of PPAR receptors in mediating antioxidant and anti-inflammatory effects and, although its protective activity has been demonstrated in several tissues, less is known about how PPARs could be involved in cochlear dysfunction induced by noise exposure. In this study, we used an in vivo model of noise-induced hearing loss to investigate how oxidative stress and inflammation participate in cochlear dysfunction through PPAR signaling pathways. Specifically, we found a progressive decrease in PPAR expression in the cochlea after acoustic trauma, paralleled by an increase in oxidative stress and inflammation. By comparing an antioxidant (Q-ter) and an anti-inflammatory (Anakinra) treatment, we demonstrated that oxidative stress is the primary element of damage in noise-induced cochlear injury and that increased inflammation can be considered a consequence of PPAR down-regulation induced by ROS production. Indeed, by decreasing oxidative stress, PPARs returned to control values, reactivating the negative control on inflammation in a feedback loop.
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6
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Nephrotoxic effects caused by co-exposure to noise and toluene in New Zealand white rabbits: A biochemical and histopathological study. Life Sci 2020; 259:118254. [PMID: 32800833 DOI: 10.1016/j.lfs.2020.118254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/31/2020] [Accepted: 08/08/2020] [Indexed: 12/13/2022]
Abstract
The biological and renal effects made by simultaneous and non-simultaneous exposure to toluene and noise were investigated. Twenty-four New Zealand white rabbits were exposed to 100 dB of white noise and 1000 ppm of toluene vapor for two weeks. The examined biochemical factors were urea, uric acid, creatinine, glucose, triglyceride, cholesterol, and albumin serum levels, measured on different days after the end of the exposure. Moreover, glutathione peroxidase activity (GPX), malondialdehyde dismutase activity (MDA), and superoxide dismutase (SOD) parameters were measured in the kidney tissue. The hematoxylin and eosin staining method was used for histopathological experiments. Overall, the noise increased albumin, uric acid, creatinine, and glucose levels, but it decreased urea, cholesterol, and triglyceride levels. Toluene decreased albumin, uric acid, and urea levels, while it increased creatinine, triglyceride, cholesterol, and glucose levels. Simultaneous exposure to noise and toluene decreased albumin, uric acid, cholesterol, and urea levels, whereas it increased creatinine, glucose, and triglyceride levels. GPX, MDA, and SOD levels increased by simultaneous and non-simultaneous exposure to noise and toluene. Furthermore, massive tubular degeneration, tubular cell vacuolization, glomerular disorganization, congestion, glomerular cell shrinkage, and unclear brush border were detected in the kidney tissue.
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Basta D, Gröschel M, Strübing I, Boyle P, Fröhlich F, Ernst A, Seidl R. Near-infrared-light pre-treatment attenuates noise-induced hearing loss in mice. PeerJ 2020; 8:e9384. [PMID: 32596055 PMCID: PMC7305775 DOI: 10.7717/peerj.9384] [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: 01/07/2020] [Accepted: 05/28/2020] [Indexed: 12/02/2022] Open
Abstract
Noise induced hearing loss (NIHL) is accompanied by a reduction of cochlear hair cells and spiral ganglion neurons. Different approaches have been applied to prevent noise induced apoptosis / necrosis. Physical intervention is one technique currently under investigation. Specific wavelengths within the near-infrared light (NIR)-spectrum are known to influence cytochrome-c-oxidase activity, which leads in turn to a decrease in apoptotic mechanisms. It has been shown recently that NIR can significantly decrease the cochlear hair cell loss if applied daily for 12 days after a noise exposure. However, it is still unclear if a single NIR-treatment, just before a noise exposure, could induce similar protective effects. Therefore, the present study was conducted to investigate the effect of a single NIR-pre-treatment aimed at preventing or limiting NIHL. The cochleae of adult NMRI-mice were pre-treated with NIR-light (808 nm, 120 mW) for 5, 10, 20, 30 or 40 minutes via the external ear canal. All animals were noised exposed immediately after the pre-treatment by broad band noise (5–20 kHz) for 30 minutes at 115 dB SPL. Frequency specific ABR-recordings to determine auditory threshold shift were carried out before the pre-treatment and two weeks after the noise exposure. The amplitude increase for wave IV and cochlear hair cell loss were determined. A further group of similar mice was noise exposed only and served as a control for the NIR pre-exposed groups. Two weeks after noise exposure, the ABR threshold shifts of NIR-treated animals were significantly lower (p < 0.05) than those of the control animals. The significance was at three frequencies for the 5-minute pre-treatment group and across the entire frequency range for all other treatment groups. Due to NIR light, the amplitude of wave four deteriorates significantly less after noise exposure than in controls. The NIR pre-treatment had no effect on the loss of outer hair cells, which was just as high with or without NIR-light pre-exposure. Relative to the entire number of outer hair cells across the whole cochlea, outer hair cell loss was rather negligible. No inner hair cell loss whatever was detected. Our results suggest that a single NIR pre-treatment induces a very effective protection of cochlear structures from noise exposure. Pre-exposure of 10 min seems to emerge as the optimal dosage for our experimental setup. A saturated effect occurred with higher dosage-treatments. These results are relevant for protection of residual hearing in otoneurosurgery such as cochlear implantation.
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Affiliation(s)
- Dietmar Basta
- Department of ENT at ukb, Charité Medical School, University of Berlin, Berlin, Germany
| | - Moritz Gröschel
- Department of ENT at ukb, Charité Medical School, University of Berlin, Berlin, Germany
| | - Ira Strübing
- Department of ENT at ukb, Charité Medical School, University of Berlin, Berlin, Germany
| | | | - Felix Fröhlich
- Department of ENT at ukb, Charité Medical School, University of Berlin, Berlin, Germany
| | - Arne Ernst
- Department of ENT at ukb, Charité Medical School, University of Berlin, Berlin, Germany
| | - Rainer Seidl
- Department of ENT at ukb, Charité Medical School, University of Berlin, Berlin, Germany
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8
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Zhang C, Frye MD, Sun W, Sharma A, Manohar S, Salvi R, Hu BH. New insights on repeated acoustic injury: Augmentation of cochlear susceptibility and inflammatory reaction resultant of prior acoustic injury. Hear Res 2020; 393:107996. [PMID: 32534268 DOI: 10.1016/j.heares.2020.107996] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 04/29/2020] [Accepted: 05/12/2020] [Indexed: 12/20/2022]
Abstract
In industrial and military settings, individuals who suffer from one episode of acoustic trauma are likely to sustain another episode of acoustic stress, creating an opportunity for a potential interaction between the two stress conditions. We previously demonstrated that acoustic overstimulation perturbs the cochlear immune environment. However, how the cochlear immune system responds to repeated acoustic overstimulation is unknown. Here, we used a mouse model to investigate the cochlear immune response to repeated stress. We reveal that exposure to an intense noise at 120 dB SPL for 1 h activates the cochlear immune response in a time-dependent fashion with substantial expansion and activation of the macrophage population in the cochlea at 2-days post-exposure. At 20-days post-exposure, the number and pro-inflammatory phenotypes of cochlear macrophages have significantly subsided, but have yet to return to homeostatic levels. Monocytes with anti-inflammatory phenotypes are recruited into the cochlea. With the presence of this residual immune activation, a second exposure to the same noise provokes an exaggerated inflammatory response as evidenced by exacerbated maturation of macrophages. Furthermore, the second noise causes greater sensory cell pathogenesis. Unlike the first noise-induced damage that occurs mainly between 0 and 2 days post-exposure, the second noise-induced damage occurs more frequently between 2 and 20 days post-exposure, the period when secondary damage takes place. These observations suggest that repeated acoustic overstimulation exacerbates cochlear inflammation and secondary sensory cell pathogenesis. Together, our results suggest that the cochlear immune system plays an important role in modulating cochlear responses to repeated acoustic stress.
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Affiliation(s)
- Celia Zhang
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Mitchell D Frye
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Wei Sun
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Ashu Sharma
- Department of Oral Biology, University at Buffalo, School of Dental Medicine, University of Buffalo, The State University of New York, Buffalo, NY, USA, 14214.
| | - Senthilvelan Manohar
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Bo Hua Hu
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
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Mechanism of aseptic inflammation upon the inner ear injury. JOURNAL OF BIO-X RESEARCH 2020. [DOI: 10.1097/jbr.0000000000000041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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10
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Haider HF, Ribeiro SF, Martins C, Ribeiro D, Trigueiros N, Szczepek AJ, Caria H, Hoare DJ, Paço J, Borrego LM. Tinnitus, hearing loss and inflammatory processes in an older Portuguese population. Int J Audiol 2019; 59:323-332. [PMID: 31829778 DOI: 10.1080/14992027.2019.1698775] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Objective: Tinnitus is associated with various conditions such as presbycusis, infectious, autoimmune and many other diseases. Our study aims to identify an association between inflammatory markers and the presence of tinnitus or hearing loss (HL).Design: Exploratory study including a structured interview, complete ENT observation, audiological and inflammatory markers evaluation.Study Sample: Sixty women and 54 men (55 to 75 years) from the Portuguese population, with or without sensory presbycusis and/or tinnitus.Results: IL10 levels were significantly lower in participants with tinnitus than in those without tinnitus. Moreover, TGF-β was lower in older participants (p = 0.034), IL1α was higher in participants with tonal tinnitus (p = 0.033), and IL2 was lower in participants who reported partial or complete residual inhibition (p = 0.019). Additionally, we observed a negative correlation between tinnitus duration and IL10 levels (r= -.281), and between HSP70 levels and tinnitus loudness (r= -.377). TNF-α and HSP70 levels appears to be sensitive to the time when samples were collected (morning or afternoon).Conclusions: The results of our study showing fluctuations in inflammatory markers along the hearing loss process, reinforce the idea that inflammatory mechanisms are involved in hearing loss pathogenesis but also in tinnitus. IL10 levels appear significantly altered in tinnitus but not in hearing loss.
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Affiliation(s)
- Haúla F Haider
- ENT Department, Hospital Cuf Infante Santo - NOVA Medical School, Lisbon, Portugal
| | - Sara F Ribeiro
- ENT Department, Hospital Cuf Infante Santo - NOVA Medical School, Lisbon, Portugal
| | - Catarina Martins
- Immunology, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Faculty of Medical Sciences, NOVA Medical School, Lisbon, Portugal.,Comprehensive Health Research Centre (CHRC), Nova Medical School, Nova University of Lisbon, Lisbon, Portugal
| | - Diogo Ribeiro
- ENT Department, Hospital Cuf Infante Santo - NOVA Medical School, Lisbon, Portugal
| | - Nuno Trigueiros
- ENT Department, Hospital Pedro Hispano, Matosinhos, Portugal
| | - Agnieszka J Szczepek
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Helena Caria
- Departamento de Ciências Biomédicas, Escola Superior de saúde do Instituto Politécnico de Setúbal, Setubal, Portugal.,Faculty of Sciences, BioISI - Biosystems and Integrative Sciences Institute, University of Lisboa, Lisboa, Portugal
| | - Derek J Hoare
- Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| | - João Paço
- ENT Department, Hospital Cuf Infante Santo - NOVA Medical School, Lisbon, Portugal
| | - Luís-Miguel Borrego
- Immunology, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Faculty of Medical Sciences, NOVA Medical School, Lisbon, Portugal.,Luz Saúde, Hospital da Luz, Immunoalergy Department, Lisbon, Portugal.,Comprehensive Health Research Centre (CHRC), Nova Medical School, Nova University of Lisbon, Lisbon, Portugal
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Köles L, Szepesy J, Berekméri E, Zelles T. Purinergic Signaling and Cochlear Injury-Targeting the Immune System? Int J Mol Sci 2019; 20:ijms20122979. [PMID: 31216722 PMCID: PMC6627352 DOI: 10.3390/ijms20122979] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/14/2019] [Accepted: 06/14/2019] [Indexed: 02/06/2023] Open
Abstract
Hearing impairment is the most common sensory deficit, affecting more than 400 million people worldwide. Sensorineural hearing losses currently lack any specific or efficient pharmacotherapy largely due to the insufficient knowledge of the pathomechanism. Purinergic signaling plays a substantial role in cochlear (patho)physiology. P2 (ionotropic P2X and the metabotropic P2Y) as well as adenosine receptors expressed on cochlear sensory and non-sensory cells are involved mostly in protective mechanisms of the cochlea. They are implicated in the sensitivity adjustment of the receptor cells by a K+ shunt and can attenuate the cochlear amplification by modifying cochlear micromechanics. Cochlear blood flow is also regulated by purines. Here, we propose to comprehend this field with the purine-immune interactions in the cochlea. The role of harmful immune mechanisms in sensorineural hearing losses has been emerging in the horizon of cochlear pathologies. In addition to decreasing hearing sensitivity and increasing cochlear blood supply, influencing the immune system can be the additional avenue for pharmacological targeting of purinergic signaling in the cochlea. Elucidating this complexity of purinergic effects on cochlear functions is necessary and it can result in development of new therapeutic approaches in hearing disabilities, especially in the noise-induced ones.
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Affiliation(s)
- László Köles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
| | - Judit Szepesy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
| | - Eszter Berekméri
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
- Department of Ecology, University of Veterinary Medicine, H-1078 Budapest, Hungary.
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary.
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12
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Paciello F, Fetoni AR, Rolesi R, Wright MB, Grassi C, Troiani D, Paludetti G. Pioglitazone Represents an Effective Therapeutic Target in Preventing Oxidative/Inflammatory Cochlear Damage Induced by Noise Exposure. Front Pharmacol 2018; 9:1103. [PMID: 30349478 PMCID: PMC6187064 DOI: 10.3389/fphar.2018.01103] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/10/2018] [Indexed: 12/18/2022] Open
Abstract
Recent progress in hearing loss research has provided strong evidence for the imbalance of cellular redox status and inflammation as common predominant mechanisms of damage affecting the organ of Corti including noise induced hearing loss. The discovery of a protective molecule acting on both mechanisms is challenging. The thiazolidinediones, a class of antidiabetic drugs including pioglitazone and rosiglitazone, have demonstrated diverse pleiotrophic effects in many tissues where they exhibit anti-inflammatory, anti-proliferative, tissue protective effects and regulators of redox balance acting as agonist of peroxisome proliferator-activated receptors (PPARs). They are members of the family of ligand regulated nuclear hormone receptors that are also expressed in several cochlear cell types, including the outer hair cells. In this study, we investigated the protective capacity of pioglitazone in a model of noise-induced hearing loss in Wistar rats and the molecular mechanisms underlying this protective effects. Specifically, we employed a formulation of pioglitazone in a biocompatible thermogel providing rapid, uniform and sustained inner ear drug delivery via transtympanic injection. Following noise exposure (120 dB, 10 kHz, 1 h), different time schedules of treatment were employed: we explored the efficacy of pioglitazone given immediately (1 h) or at delayed time points (24 and 48 h) after noise exposure and the time course and extent of hearing recovery were assessed. We found that pioglitazone was able to protect auditory function at the mid-high frequencies and to limit cell death in the cochlear basal/middle turn, damaged by noise exposure. Immunofluorescence and western blot analysis provided evidence that pioglitazone mediates both anti-inflammatory and anti-oxidant effects by decreasing NF-κB and IL-1β expression in the cochlea and opposing the oxidative damage induced by noise insult. These results suggest that intratympanic pioglitazone can be considered a valid therapeutic strategy for attenuating noise-induced hearing loss and cochlear damage, reducing inflammatory signaling and restoring cochlear redox balance.
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Affiliation(s)
- Fabiola Paciello
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy.,Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy.,Institute of Cell Biology and Neurobiology, CNR, Rome, Italy
| | - Anna Rita Fetoni
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy.,Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy.,Institute of Cell Biology and Neurobiology, CNR, Rome, Italy
| | - Rolando Rolesi
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | | | - Claudio Grassi
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy.,Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Diana Troiani
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Gaetano Paludetti
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy.,Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy
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13
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Hu BH, Zhang C, Frye MD. Immune cells and non-immune cells with immune function in mammalian cochleae. Hear Res 2018; 362:14-24. [PMID: 29310977 PMCID: PMC5911222 DOI: 10.1016/j.heares.2017.12.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/21/2017] [Accepted: 12/08/2017] [Indexed: 02/07/2023]
Abstract
The cochlea has an immune environment dominated by macrophages under resting conditions. When stressed, circulating monocytes enter the cochlea. These immune mediators, along with cochlear resident cells, organize a complex defense response against pathological challenges. Since the cochlea has minimal exposure to pathogens, most inflammatory conditions in the cochlea are sterile. Although the immune response is initiated for the protection of the cochlea, off-target effects can cause collateral damage to cochlear cells. A better understanding of cochlear immune capacity and regulation would therefore lead to development of new therapeutic treatments. Over the past decade, there have been many advances in our understanding of cochlear immune capacity. In this review, we provide an update and overview of the cellular components of cochlear immune capacity with a focus on macrophages in mammalian cochleae. We describe the composition and distribution of immune cells in the cochlea and suggest that phenotypic and functional characteristics of macrophages have site-specific diversity. We also highlight the response of immune cells to acute and chronic stresses and comment on the potential function of immune cells in cochlear homeostasis and disease development. Finally, we briefly review potential roles for cochlear resident cells in immune activities of the cochlea.
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Affiliation(s)
- Bo Hua Hu
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
| | - Celia Zhang
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
| | - Mitchell D Frye
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
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14
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Marchiori LLM, Dias ACM, Gonçalvez AS, Poly-Frederico RC, Doi MY. Association between polymorphism of tumor necrosis factor alpha (tnfα) in the region -308 g/a with tinnitus in the elderly with a history of occupational noise exposure. Noise Health 2018; 20:37-41. [PMID: 29676293 PMCID: PMC5926314 DOI: 10.4103/nah.nah_34_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Context: Tinnitus is a common disorder that occurs frequently across all strata of population and has an important health concern and is often associated with different forms of the hearing loss of varying severity. Aims: To investigate the association between the polymorphism of tumor necrosis factor alpha (TNFα) in the region −308 G/A with the susceptibility to tinnitus in individuals with the history of exposure to occupational noise. Settings and Design: This was a cross-sectional study with a sample of 179 independent elderly people above 60 years of age. Materials and Methods: Information on exposure to occupational noise was obtained by interviews. Audiological evaluation was performed using pure tone audiometry and genotyped through polymerase chain reaction by restriction fragment length polymorphism. Statistical Analysis Used: Data were analyzed using the chi-square test and the odds ratio (OR), with the significance level set at 5%. Results: Among elderly with tinnitus (43.01%), 33.76% had a history of exposure to occupational noise. A statistically significant association was found between genotype frequencies of the TNFα gene in the −308 G/A region and the complaint of tinnitus (P = 0.04 and χ2 = 4.19). The elderly with the G allele were less likely to have tinnitus due to occupational noise exposure when compared to those carrying the A allele (OR = 2.74; 95% CI: 1.56–4.81; P < 0.0005). Conclusion: This study suggests an association between the TNFα with susceptibility to tinnitus in individuals with a history of exposure to occupational noise.
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Affiliation(s)
- Luciana L M Marchiori
- Centre of Biological and Health Sciences (CCBS), University of Northern Paraná (UNOPAR), Londrina, PR, Brazil
| | - Ana C M Dias
- Centre of Biological and Health Sciences (CCBS), University of Northern Paraná (UNOPAR), Londrina, PR, Brazil
| | - Alyne S Gonçalvez
- Centre of Biological and Health Sciences (CCBS), University of Northern Paraná (UNOPAR), Londrina, PR, Brazil
| | - Regina C Poly-Frederico
- Research Centre in Health Sciences (CPCS), University of Northern Paraná (UNOPAR), Londrina, PR, Brazil
| | - Marcelo Y Doi
- Research Centre in Health Sciences (CPCS), University of Northern Paraná (UNOPAR), Londrina, PR, Brazil
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15
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Oral administration of geranylgeranylacetone to protect vestibular hair cells. Auris Nasus Larynx 2017; 45:412-416. [PMID: 28781154 DOI: 10.1016/j.anl.2017.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/06/2017] [Accepted: 07/11/2017] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We recently reported that the heat shock response played a major role in the protection of hair cells against stress. Oral administration of the heat shock inducer, geranylgeranylacetone (GGA) protected hair cells against intense noise. In our present study, we investigated the effect of GGA on vestibular hair cell death induced by an aminoglycoside. METHODS We used CBA/N mice aged 4-6 weeks. The mice were divided into two groups, GGA and control. Mice in the GGA group were fed a diet containing GGA (0.5%) for 4 weeks, and those in the control group were fed a standard diet. Immunohistochemical analyses for Hsp70 were performed in four animals. The utricles of the remaining animals were cultured in medium for 24h with neomycin to induce hair cell death. After fixation, the vestibular hair cells were immunohistochemically stained against calmodulin, and hair cell survival was evaluated. RESULTS The vestibular hair cells of mice in the GGA group expressed Hsp70. In addition, after exposure to neomycin, vestibular hair cell survival was higher in the GGA group than in the control group. CONCLUSION Our results demonstrated the oral administration of GGA induced the heat shock response in the vestibule and could protect sensory cells.
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16
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Kalinec GM, Lomberk G, Urrutia RA, Kalinec F. Resolution of Cochlear Inflammation: Novel Target for Preventing or Ameliorating Drug-, Noise- and Age-related Hearing Loss. Front Cell Neurosci 2017; 11:192. [PMID: 28736517 PMCID: PMC5500902 DOI: 10.3389/fncel.2017.00192] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 06/20/2017] [Indexed: 12/11/2022] Open
Abstract
A significant number of studies support the idea that inflammatory responses are intimately associated with drug-, noise- and age-related hearing loss (DRHL, NRHL and ARHL). Consequently, several clinical strategies aimed at reducing auditory dysfunction by preventing inflammation are currently under intense scrutiny. Inflammation, however, is a normal adaptive response aimed at restoring tissue functionality and homeostasis after infection, tissue injury and even stress under sterile conditions, and suppressing it could have unintended negative consequences. Therefore, an appropriate approach to prevent or ameliorate DRHL, NRHL and ARHL should involve improving the resolution of the inflammatory process in the cochlea rather than inhibiting this phenomenon. The resolution of inflammation is not a passive response but rather an active, highly controlled and coordinated process. Inflammation by itself produces specialized pro-resolving mediators with critical functions, including essential fatty acid derivatives (lipoxins, resolvins, protectins and maresins), proteins and peptides such as annexin A1 and galectins, purines (adenosine), gaseous mediators (NO, H2S and CO), as well as neuromodulators like acetylcholine and netrin-1. In this review article, we describe recent advances in the understanding of the resolution phase of inflammation and highlight therapeutic strategies that might be useful in preventing inflammation-induced cochlear damage. In particular, we emphasize beneficial approaches that have been tested in pre-clinical models of inflammatory responses induced by recognized ototoxic drugs such as cisplatin and aminoglycoside antibiotics. Since these studies suggest that improving the resolution process could be useful for the prevention of inflammation-associated diseases in humans, we discuss the potential application of similar strategies to prevent or mitigate DRHL, NRHL and ARHL.
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Affiliation(s)
- Gilda M Kalinec
- Laboratory of Auditory Cell Biology, Department of Head and Neck Surgery, David Geffen School of Medicine, University of CaliforniaLos Angeles, Los Angeles, CA, United States
| | - Gwen Lomberk
- Epigenetics and Chromatin Dynamics Laboratory, Translational Epigenomic Program, Center for Individualized Medicine (CIM) Mayo ClinicRochester, MN, United States
| | - Raul A Urrutia
- Epigenetics and Chromatin Dynamics Laboratory, Translational Epigenomic Program, Center for Individualized Medicine (CIM) Mayo ClinicRochester, MN, United States
| | - Federico Kalinec
- Laboratory of Auditory Cell Biology, Department of Head and Neck Surgery, David Geffen School of Medicine, University of CaliforniaLos Angeles, Los Angeles, CA, United States
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17
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Lo WC, Wu CT, Lee HC, Young YH, Chang YL, Cheng PW. Evaluation of geranylgeranylacetone against cisplatin-induced ototoxicity by auditory brainstem response, heat shock proteins and oxidative levels in guinea pigs. Neurotoxicol Teratol 2017; 61:29-35. [PMID: 28344103 DOI: 10.1016/j.ntt.2017.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 02/25/2017] [Accepted: 03/21/2017] [Indexed: 11/28/2022]
Abstract
This study aims to assess whether geranylgeranylacetone (GGA) could reduce ototoxicity induced by cisplatin through upregulation of not only heat shock protein(HSP)-70, but also HSP-27 and HSP-40, and to study if GGA would reduce cisplatin-induced increase in oxidative stress. 48 guinea pigs were used in this study and treated with the following regimen: 0.5% CMC (sodium carboxymethyl cellulose) control for 7days, GGA (600mg/kg/d) for 7days, a combination of GGA (600mg/kg) for 7days and then one dose of 10mg/kg cisplatin (GGA+Cis), and a combination of CMC for 7days and then 10mg/kg cisplatin (cisplatin group). Auditory brainstem response (ABR) measurement was performed in each animal at time before treatment and 7days after the last dose. Additionally, HSPs, nitric oxide (NO), and lipid peroxidation (LPO) levels in cochlear membranous tissues were assessed. The mean ABR thresholds in the cisplatin group were significantly (p<0.05) increased when compared to the other three groups. In guinea pigs receiving both GGA and cisplatin, the mean threshold shift (TS) were smaller (p<0.05) than those of the cisplatin group, but larger (p<0.05) than those of the CMC control or GGA only group with statistical significance. Compared to the GGA only group or the group treated with GGA+Cis, the cisplatin group had the highest (p<0.05) oxidative stress (NO and LPO levels), and the lowest (p<0.05) mean HSPs expression levels. It can be concluded that GGA attenuate ototoxicity induced by cisplatin through upregulation of HSP-27, -40, and -70. Moreover, increased oxidative stress induced by cisplatin in the cochlea membranous tissue could be reduced by pre-treatment of GGA.
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Affiliation(s)
- Wu-Chia Lo
- Graduate Institute of Pathology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan
| | - Chen-Tu Wu
- Graduate Institute of Pathology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Pathology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Hillary Chiao Lee
- Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan
| | - Yi-Ho Young
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yih-Leong Chang
- Graduate Institute of Pathology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Pathology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
| | - Po-Wen Cheng
- Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan.
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18
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Tamura A, Matsunobu T, Tamura R, Kawauchi S, Sato S, Shiotani A. Photobiomodulation rescues the cochlea from noise-induced hearing loss via upregulating nuclear factor κB expression in rats. Brain Res 2016; 1646:467-474. [PMID: 27342816 DOI: 10.1016/j.brainres.2016.06.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/16/2016] [Accepted: 06/20/2016] [Indexed: 12/12/2022]
Abstract
Photobiomodulation (PBM) is a noninvasive treatment that can be neuroprotective, although the underlying mechanisms remain unclear. In the present study, we assessed the mechanism of PBM as a novel treatment for noise-induced hearing loss, focusing on the nuclear factor (NF)-κB signaling pathway. Sprague-Dawley rats were exposed to 1-octave band noise centered at 4kHz for 5h (121dB). After noise exposure, their right ears were irradiated with an 808nm diode laser beam at an output power density of 165mW/cm(2) for 30min a day for 5 consecutive days. Measurement of the auditory brainstem response revealed an accelerated recovery of auditory function in the groups treated with PBM compared with the non-treatment group at 4, 7, and 14 days after noise exposure. Immunofluorescent image analysis for inducible nitric oxide synthase and cleaved caspase-3 showed lesser immunoreactivities in outer hair cells in the PBM group compared with the non-treatment group. However, immunofluorescent image analysis for NF-κB, an upstream protein of inducible nitric oxide synthase, revealed greater activation in the PBM group compared with the naïve and non-treatment groups. Western blot analysis for NF-κB also showed stronger activation in the cochlear tissues in the PBM group compared with the naïve and non-treatment groups (p<0.01, each). These data suggest that PBM activates NF-κB to induce protection against inducible nitric oxide synthase-triggered oxidative stress and caspase-3-mediated apoptosis that occur following noise-induced hearing loss.
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Affiliation(s)
- Atsushi Tamura
- Department of Otolaryngology - Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-0042, Japan.
| | - Takeshi Matsunobu
- Department of Otolaryngology - Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-0042, Japan
| | - Risa Tamura
- Department of Physiology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-0042, Japan
| | - Satoko Kawauchi
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, 3-2 Namiki, Tokorozawa, Saitama 359-0042, Japan
| | - Shunichi Sato
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, 3-2 Namiki, Tokorozawa, Saitama 359-0042, Japan
| | - Akihiro Shiotani
- Department of Otolaryngology - Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-0042, Japan
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19
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Vethanayagam RR, Yang W, Dong Y, Hu BH. Toll-like receptor 4 modulates the cochlear immune response to acoustic injury. Cell Death Dis 2016; 7:e2245. [PMID: 27253409 PMCID: PMC5143385 DOI: 10.1038/cddis.2016.156] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/29/2016] [Accepted: 05/03/2016] [Indexed: 12/13/2022]
Abstract
Acoustic overstimulation traumatizes the cochlea, resulting in auditory dysfunction. As a consequence of acoustic injury, the immune system in the cochlea is activated, leading to the production of inflammatory mediators and the infiltration of immune cells. However, the molecular mechanisms responsible for initiating these immune responses remain unclear. Here, we investigate the functional role of Toll-like receptor 4 (Tlr4), a cellular receptor that activates the innate immune system, in the regulation of cochlear responses to acoustic overstimulation. Using a Tlr4 knockout mouse model, we examined how Tlr4 deficiency affects sensory cell pathogenesis, auditory dysfunction and cochlear immune activity. We demonstrate that Tlr4 knockout does not affect sensory cell viability under physiological conditions, but reduces the level of sensory cell damage and cochlear dysfunction after acoustic injury. Together, these findings suggest that Tlr4 promotes sensory cell degeneration and cochlear dysfunction after acoustic injury. Acoustic injury provokes a site-dependent inflammatory response in both the organ of Corti and the tissues of the lateral wall and basilar membrane. Tlr4 deficiency affects these inflammatory responses in a site-dependent manner. In the organ of Corti, loss of Tlr4 function suppresses the production of interleukin 6 (Il6), a pro-inflammatory molecule, after acoustic injury. By contrast, the production of inflammatory mediators, including Il6, persists in the lateral wall and basilar membrane. In addition to immune molecules, Tlr4 knockout inhibits the expression of major histocompatibility complex class II, an antigen-presenting molecule, in macrophages, suggesting that Tlr4 participates in the antigen-presenting function of macrophages after acoustic trauma. Together, these results suggest that Tlr4 regulates multiple aspects of the immune response in the cochlea and contributes to cochlear pathogenesis after acoustic injury.
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Affiliation(s)
- R R Vethanayagam
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - W Yang
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Y Dong
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - B H Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
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20
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Characterisation of cochlear inflammation in mice following acute and chronic noise exposure. Histochem Cell Biol 2016; 146:219-30. [PMID: 27109494 DOI: 10.1007/s00418-016-1436-5] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2016] [Indexed: 12/17/2022]
Abstract
Oxidative stress has been established as the key mechanism of the cochlear damage underlying noise-induced hearing loss, however, emerging evidence suggests that cochlear inflammation may also be a major contributor. This study aimed to improve our understanding of the cochlear inflammatory response associated with acute and chronic noise exposure. C57BL/6 mice were exposed to acute traumatic noise (100 dBSPL, 8-16 kHz for 24 h) and their cochleae collected at various intervals thereafter, up to 7 days. Using quantitative RT-PCR and immunohistochemistry, changes in expression levels of proinflammatory cytokines (TNF-α, IL-1β), chemokines (CCL2) and cell adhesion molecules (ICAM-1) were studied. All gene transcripts displayed similar dynamics of expression, with an early upregulation at 6 h post-exposure, followed by a second peak at 7 days. ICAM-1 immunoexpression increased significantly in the inferior region of the spiral ligament, peaking 24 h post-exposure. The early expression of proinflammatory mediators likely mediates the recruitment and extravasation of inflammatory cells into the noise-exposed cochlea. The occurrence of the latter expression peak is not clear, but it may be associated with reparative processes initiated in response to cochlear damage. Chronic exposure to moderate noise (90 dBSPL, 8-16 kHz, 2 h/day, up to 4 weeks) also elicited an inflammatory response, reaching a maximum after 2 weeks, suggesting that cochlear damage and hearing loss associated with chronic environmental noise exposure may be linked to inflammatory processes in the cochlea. This study thus provides further insight into the dynamics of the cochlear inflammatory response induced by exposure to acute and chronic noise.
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21
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Doi MY, Dias ACM, Poly-Frederico RC, Maria MGSR, de Oliveira MN, de Moraes Marchiori LL. Association between polymorphism of interleukin-6 in the region -174G/C and tinnitus in the elderly with a history of occupational noise exposure. Noise Health 2015; 17:406-10. [PMID: 26572700 PMCID: PMC4900473 DOI: 10.4103/1463-1741.169703] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Tinnitus is a symptom usually related to cochlear change that may arise from noise exposure and induces expression of proinflammatory cytokines including interleukin-6 (IL6). This study aimed to evaluate the association between the polymorphism of the IL6 gene in the region 174G/C and tinnitus in elderly with history of occupational noise exposure. SETTINGS AND DESIGN This was a cross-sectional study with a sample of 179 independent elderly individuals aged >60 years. Information on exposure to occupational noise was obtained by interviews. Audiological evaluation was performed using pure tone audiometry and genotyped through polymerase chain reaction by restriction fragment length polymorphism (PCR-RFLP). Data were analyzed using the chi-square test and the odds ratio (OR), with the significance level set at 5%. Among the study subjects, 24.6% were homozygous for the G allele, 39.7% were homozygous for the C allele, and 35.8% were heterozygous for IL6 (P > 0.05). Of these, 33.5% reported noise exposure history, with 42.5% having tinnitus. We found significant association between the genotype and allele frequencies of the IL6 -174 gene (rs1800795) and tinnitus among the elderly with history of exposure to occupational noise (P = 0.03). The elderly with the C allele were less likely to have tinnitus associated with history of exposure to occupational noise [OR = 0.167, confidence interval (CI) 95% 0.167-0.749; P = 0.004] when compared to those carrying the G allele. This study suggests that there is an association between polymorphisms in the IL6 gene at region - 174G/C and susceptibility to tinnitus.
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Affiliation(s)
- Marcelo Yugi Doi
- Department of Centre of Research in Health Sciences, University of Northern Parana, Londrina-PR, Brazil
| | | | - Regina Célia Poly-Frederico
- Department of Molecular Biology, Centre of Research in Health Sciences, University of Northern Parana, Londrina-PR, Brazil
| | | | | | - Luciana Lozza de Moraes Marchiori
- Department of Audiology and Speech Therapy, Centre of Research in Health Sciences, University of Northern Parana, Londrina-PR, Brazil
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22
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Activation of the antigen presentation function of mononuclear phagocyte populations associated with the basilar membrane of the cochlea after acoustic overstimulation. Neuroscience 2015; 303:1-15. [PMID: 26102003 DOI: 10.1016/j.neuroscience.2015.05.081] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 04/30/2015] [Accepted: 05/07/2015] [Indexed: 12/20/2022]
Abstract
The immune response is an important component of the cochlear response to stress. As an important player in the cochlear immune system, the basilar membrane immune cells reside on the surface of the scala tympani side of the basilar membrane. At present, the immune cell properties in this region and their responses to stress are not well understood. Here, we investigated the functional role of these immune cells in the immune response to acoustic overstimulation. This study reveals that tissue macrophages are present in the entire length of the basilar membrane under steady-state conditions. Notably, these cells in the apical and the basal sections of the basilar membrane display distinct morphologies and immune protein expression patterns. Following acoustic trauma, monocytes infiltrate into the region of the basilar membrane, and the infiltrated cells transform into macrophages. While monocyte infiltration and transformation occur in both the apical and the basal sections of the basilar membrane, only the basal monocytes and macrophages display a marked increase in the expression of major histocompatibility complex (MHC) II and class II transactivator (CIITA), a MHC II production cofactor, suggesting the site-dependent activation of antigen-presenting function. Consistent with the increased expression of the antigen-presenting proteins, CD4(+) T cells, the antigen-presenting partner, infiltrate into the region of the basilar membrane where antigen-presenting proteins are upregulated. Further pathological analyses revealed that the basal section of the cochlea displays a greater level of sensory cell damage, which is spatially correlated with the region of antigen-presenting activity. Together, these results suggest that the antigen-presenting function of the mononuclear phagocyte population is activated in response to acoustic trauma, which could bridge the innate immune response to adaptive immunity.
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Murillo-Cuesta S, Rodríguez-de la Rosa L, Contreras J, Celaya AM, Camarero G, Rivera T, Varela-Nieto I. Transforming growth factor β1 inhibition protects from noise-induced hearing loss. Front Aging Neurosci 2015; 7:32. [PMID: 25852546 PMCID: PMC4367183 DOI: 10.3389/fnagi.2015.00032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/28/2015] [Indexed: 12/20/2022] Open
Abstract
Excessive exposure to noise damages the principal cochlear structures leading to hearing impairment. Inflammatory and immune responses are central mechanisms in cochlear defensive response to noise but, if unregulated, they contribute to inner ear damage and hearing loss. Transforming growth factor β (TGF-β) is a key regulator of both responses and high levels of this factor have been associated with cochlear injury in hearing loss animal models. To evaluate the potential of targeting TGF-β as a therapeutic strategy for preventing or ameliorating noise-induced hearing loss (NIHL), we studied the auditory function, cochlear morphology, gene expression and oxidative stress markers in mice exposed to noise and treated with TGF-β1 peptidic inhibitors P17 and P144, just before or immediately after noise insult. Our results indicate that systemic administration of both peptides significantly improved both the evolution of hearing thresholds and the degenerative changes induced by noise-exposure in lateral wall structures. Moreover, treatments ameliorated the inflammatory state and redox balance. These therapeutic effects were dose-dependent and more effective if the TGF-β1 inhibitors were administered prior to inducing the injury. In conclusion, inhibition of TGF-β1 actions with antagonistic peptides represents a new, promising therapeutic strategy for the prevention and repair of noise-induced cochlear damage.
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Affiliation(s)
- Silvia Murillo-Cuesta
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
| | - Lourdes Rodríguez-de la Rosa
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
| | - Julio Contreras
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Veterinary Faculty, Complutense University of Madrid Madrid, Spain
| | - Adelaida M Celaya
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain
| | - Guadalupe Camarero
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
| | - Teresa Rivera
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Príncipe de Asturias University Hospital, University of Alcalá, Alcalá de Henares Madrid, Spain
| | - Isabel Varela-Nieto
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
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Takumi Y, Nishio SY, Mugridge K, Oguchi T, Hashimoto S, Suzuki N, Iwasaki S, Jolly C, Usami SI. Gene expression pattern after insertion of dexamethasone-eluting electrode into the guinea pig cochlea. PLoS One 2014; 9:e110238. [PMID: 25329543 PMCID: PMC4203767 DOI: 10.1371/journal.pone.0110238] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 09/17/2014] [Indexed: 11/25/2022] Open
Abstract
A cochlear implant is an indispensable apparatus for a profound hearing loss patient. But insertion of the electrode entails a great deal of stress to the cochlea, and may cause irreversible damage to hair cells and related nerve structure. Although damage prevention effects of dexamethasone have been reported, long-term administration is difficult. In this study, we used a dexamethasone-eluting electrode in the guinea pig cochlea, and compared the gene expression after 7 days insertion with that of a normal electrode and non-surgically treated control by microarray. 40 genes were up-regulated 2-fold or more in the normal electrode group compared to the non-surgically treated group. Most of the up-regulated genes were associated with immune response and inflammation. In the dexamethasone-eluting group, compared to the normal electrode group, 7 of the 40 genes were further up-regulated, while 12 of them were down-regulated and there was a tendency to return to the non-surgical condition. 9 genes were down-regulated 2-fold or less with normal electrode insertion, and 4 of the 9 tended to return to the non-surgical condition in the dexamethasone-eluting group. These genes are certainly involved in the maintenance of the physiological functions of the cochlea. Our results indicate that the dexamethasone-eluting electrode will have an effect on the normalization of homeostasis in the cochlea.
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Affiliation(s)
- Yutaka Takumi
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto, Japan
| | - Shin-ya Nishio
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto, Japan
| | | | - Tomohiro Oguchi
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Shigenari Hashimoto
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Nobuyoshi Suzuki
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Satoshi Iwasaki
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, Matsumoto, Japan
| | | | - Shin-ichi Usami
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
- * E-mail:
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Cai Q, Vethanayagam RR, Yang S, Bard J, Jamison J, Cartwright D, Dong Y, Hu BH. Molecular profile of cochlear immunity in the resident cells of the organ of Corti. J Neuroinflammation 2014; 11:173. [PMID: 25311735 PMCID: PMC4198756 DOI: 10.1186/s12974-014-0173-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/25/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The cochlea is the sensory organ of hearing. In the cochlea, the organ of Corti houses sensory cells that are susceptible to pathological insults. While the organ of Corti lacks immune cells, it does have the capacity for immune activity. We hypothesized that resident cells in the organ of Corti were responsible for the stress-induced immune response of the organ of Corti. This study profiled the molecular composition of the immune system in the organ of Corti and examined the immune response of non-immune epithelial cells to acoustic overstimulation. METHODS Using high-throughput RNA-sequencing and qRT-PCR arrays, we identified immune- and inflammation-related genes in both the cochlear sensory epithelium and the organ of Corti. Using bioinformatics analyses, we cataloged the immune genes expressed. We then examined the response of these genes to acoustic overstimulation and determined how changes in immune gene expression were related to sensory cell damage. RESULTS The RNA-sequencing analysis reveals robust expression of immune-related genes in the cochlear sensory epithelium. The qRT-PCR array analysis confirms that many of these genes are constitutively expressed in the resident cells of the organ of Corti. Bioinformatics analyses reveal that the genes expressed are linked to the Toll-like receptor signaling pathway. We demonstrate that expression of Toll-like receptor signaling genes is predominantly from the supporting cells in the organ of Corti cells. Importantly, our data demonstrate that these Toll-like receptor pathway genes are able to respond to acoustic trauma and that their expression changes are associated with sensory cell damage. CONCLUSION The cochlear resident cells in the organ of Corti have immune capacity and participate in the cochlear immune response to acoustic overstimulation.
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Affiliation(s)
| | | | | | | | | | | | | | - Bo Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo 14214, NY, USA.
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Braga MP, Maciel SM, Marchiori LLDM, Poli-Frederico RC. Association between interleukin-6 polymorphism in the −174 G/C region and hearing loss in the elderly with a history of occupational noise exposure. Braz J Otorhinolaryngol 2014; 80:373-8. [PMID: 25303810 PMCID: PMC9444601 DOI: 10.1016/j.bjorl.2014.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 02/01/2014] [Indexed: 12/20/2022] Open
Abstract
Introduction Objective Methods Results Conclusion
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Neuroprotective effects of geranylgeranylacetone in experimental traumatic brain injury. J Cereb Blood Flow Metab 2013; 33:1897-908. [PMID: 23942364 PMCID: PMC3851897 DOI: 10.1038/jcbfm.2013.144] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 07/19/2013] [Accepted: 07/22/2013] [Indexed: 12/11/2022]
Abstract
Geranylgeranylacetone (GGA) is an inducer of heat-shock protein 70 (HSP70) that has been used clinically for many years as an antiulcer treatment. It is centrally active after oral administration and is neuroprotective in experimental brain ischemia/stroke models. We examined the effects of single oral GGA before treatment (800 mg/kg, 48 hours before trauma) or after treatment (800 mg/kg, 3 hours after trauma) on long-term functional recovery and histologic outcomes after moderate-level controlled cortical impact, an experimental traumatic brain injury (TBI) model in mice. The GGA pretreatment increased the number of HSP70(+) cells and attenuated posttraumatic α-fodrin cleavage, a marker of apoptotic cell death. It also improved sensorimotor performance on a beam walk task; enhanced recovery of cognitive/affective function in the Morris water maze, novel object recognition, and tail-suspension tests; and improved outcomes using a composite neuroscore. Furthermore, GGA pretreatment reduced the lesion size and neuronal loss in the hippocampus, cortex, and thalamus, and decreased microglial activation in the cortex when compared with vehicle-treated TBI controls. Notably, GGA was also effective in a posttreatment paradigm, showing significant improvements in sensorimotor function, and reducing cortical neuronal loss. Given these neuroprotective actions and considering its longstanding clinical use, GGA should be considered for the clinical treatment of TBI.
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Tan WJT, Thorne PR, Vlajkovic SM. Noise-induced cochlear inflammation. World J Otorhinolaryngol 2013; 3:89-99. [DOI: 10.5319/wjo.v3.i3.89] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 08/08/2013] [Accepted: 08/20/2013] [Indexed: 02/06/2023] Open
Abstract
Hearing loss is the most common sensory disability with considerable social and economic implications. According to recent World Health Organization estimates, 360 million people worldwide suffer from moderate to profound hearing loss. Exposure to excessive noise is one of the major causes of sensorineural hearing loss, secondary only to age-related hearing loss (presbyacusis). Since cochlear tissues have limited abilities of repair and regeneration, this damage can be irreversible, leading to cochlear dysfunction and permanent hearing loss. Recent studies have shown that cochlear inflammation can be induced by noise exposure and contribute to the overall pathogenesis of cochlear injury and hearing loss. The cochlea is separated from the systemic circulation by the blood-labyrinth barrier, which is physiologically similar to the blood-brain barrier of the central nervous system. Because of this feature, the cochlea was originally considered an immunologically privileged organ. However, this postulate has been challenged by the evidence of an inflammatory response in the cochlea in the presence of bacterial or viral pathogens or antigens that can cause labyrinthitis. Although the main purpose of the inflammatory reaction is to protect against invading pathogens, the inflammatory response can also cause significant bystander injury to the delicate structures of the cochlea. The cochlear inflammatory response is characterised by the generation of proinflammatory mediators (cytokines, chemokines and adhesion molecules), and the recruitment of inflammatory cells (leukocytes). Here, we present an overview of the current research on cochlear inflammation, with particular emphasis on noise-induced cochlear inflammation. We also discuss treatment strategies aimed at the suppression of inflammation, which may potentially lead to mitigation of hearing loss.
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