1
|
Ala-Kokko N, Baek I, Song Y. Development of Tissue-Engineered Model of Fibrotic Scarring after Spinal Cord Injury to Study Astrocyte Activation and Neurite Outgrowth In Vitro. ACS Biomater Sci Eng 2024. [PMID: 39259933 DOI: 10.1021/acsbiomaterials.4c01100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2024]
Abstract
Traumatic spinal cord injuries (SCI) are debilitating injuries affecting twenty-seven million people worldwide and cause functional impairments. Despite decades of research and medical advancements, current treatment options for SCI remain limited, in part due to the complex pathophysiology of spinal cord lesions including cellular transformation and extracellular matrix (ECM) remodeling. Recent studies have increased focus on fibrotic scarring after SCI, and yet much remains unclear about the impact of fibrotic scarring on SCI lesion progression. Here, using collagen and decellularized spinal cord-based composite hydrogels, a three-dimensional (3D) cell culture model mimicking the fibrous core of spinal cord lesions was implemented to investigate its influence on the surrounding astrocytes. To mimic the fibrotic milieu, collagen fibril thickness was tuned using previously established temperature-controlled casting methods. In our platforms, astrocytes in fibro-mimetic hydrogels exhibited increased levels of activation markers such as glial fibrillary acidic protein and N-cadherin. Furthermore, astrocytes in fibro-mimetic hydrogels deposited more fibronectin and laminin, further hinting that astrocytes may also contribute to fibrotic scarring. These markers were decreased when Rho-ROCK and integrin β1 were inhibited via pharmacological inhibitors. Mechanistic analysis of Yes-associated protein reveals that blocking integrin β1 prevents mechanosensing of astrocytes, contributing to altered phenotypes in variable culture conditions. In the presence of these inhibitors, astrocytes increased the secretion of brain-derived neurotrophic factor, and a greater degree of dorsal root ganglia neurite infiltration into the underlying hydrogels was observed. Altogether, this study presents a novel tissue-engineered platform to study fibrotic scarring after SCI and may be a useful platform to advance our understanding of SCI lesion aggravation.
Collapse
Affiliation(s)
- Nikolas Ala-Kokko
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Inha Baek
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Younghye Song
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| |
Collapse
|
2
|
Lim KH, Park S, Han E, Yoon HS, Lee Y, Hong S, Hyun K, Baek SH, Baek HW, Chan Rah Y, Choi J. Protective effects of Y-27632 against cisplatin-induced ototoxicity: A zebrafish model Y-27632 and cisplatin-induced ototoxicity. Food Chem Toxicol 2024; 190:114792. [PMID: 38849049 DOI: 10.1016/j.fct.2024.114792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 05/01/2024] [Accepted: 06/04/2024] [Indexed: 06/09/2024]
Abstract
Cisplatin is an effective chemotherapy agent against various solid malignancies; however, it is associated with irreversible bilateral sensorineural hearing loss, emphasizing the need for drug development to prevent this complication, with the current options being very limited. Rho-associated coiled-coil-containing protein kinase (ROCK) is a serine-threonine protein kinase involved in various cellular processes, including apoptosis regulation. In this study, we used a transgenic zebrafish model (Brn3C: EGFP) in which hair cells within neuromasts are observed in green under fluorescent microscopy without the need for staining. Zebrafish larvae were exposed to cisplatin alone or in combination with various concentrations of Y-27632, a potent ROCK inhibitor. Hair cell counts, apoptosis assessments using the terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay, FM1-43FX labeling assay and behavioral analyses (startle response and rheotaxis) were performed to evaluate the protective effects of Y-27632 against cisplatin-induced ototoxicity. Cisplatin treatment reduced the number of hair cells in neuromasts, induced apoptosis, and impaired zebrafish larval behaviors. Y-27632 demonstrated a dose-dependent protective effect against cisplatin-induced hair cell loss and apoptosis. These findings suggest that Y-27632, as a ROCK inhibitor, mitigates cisplatin-induced hair cell loss and associated ototoxicity in zebrafish.
Collapse
Affiliation(s)
- Kang Hyeon Lim
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea
| | - Saemi Park
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea
| | - Eunjung Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea
| | - Hee Soo Yoon
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea
| | - Yunkyoung Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea; Zebrafish Translational Medical Research Center, Korea University, Ansan, Republic of Korea
| | - Sumin Hong
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea
| | - Kyungtae Hyun
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea
| | - Seung Hwa Baek
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea; Zebrafish Translational Medical Research Center, Korea University, Ansan, Republic of Korea
| | - Hyun Woo Baek
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea
| | - Yoon Chan Rah
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea
| | - June Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, Ansan, Gyeonggi, Republic of Korea; Zebrafish Translational Medical Research Center, Korea University, Ansan, Republic of Korea.
| |
Collapse
|
3
|
Carroll AM, Riley JR, Borland MS, Danaphongse TT, Hays SA, Kilgard MP, Engineer CT. Bursts of vagus nerve stimulation paired with auditory rehabilitation fail to improve speech sound perception in rats with hearing loss. iScience 2024; 27:109527. [PMID: 38585658 PMCID: PMC10995867 DOI: 10.1016/j.isci.2024.109527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/09/2023] [Accepted: 03/15/2024] [Indexed: 04/09/2024] Open
Abstract
Hearing loss can lead to long-lasting effects on the central nervous system, and current therapies, such as auditory training and rehabilitation, show mixed success in improving perception and speech comprehension. Vagus nerve stimulation (VNS) is an adjunctive therapy that can be paired with rehabilitation to facilitate behavioral recovery after neural injury. However, VNS for auditory recovery has not been tested after severe hearing loss or significant damage to peripheral receptors. This study investigated the utility of pairing VNS with passive or active auditory rehabilitation in a rat model of noise-induced hearing loss. Although auditory rehabilitation helped rats improve their frequency discrimination, learn novel speech discrimination tasks, and achieve speech-in-noise performance similar to normal hearing controls, VNS did not enhance recovery of speech sound perception. These results highlight the limitations of VNS as an adjunctive therapy for hearing loss rehabilitation and suggest that optimal benefits from neuromodulation may require restored peripheral signaling.
Collapse
Affiliation(s)
- Alan M. Carroll
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Jonathan R. Riley
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Michael S. Borland
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Tanya T. Danaphongse
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Seth A. Hays
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Michael P. Kilgard
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Crystal T. Engineer
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| |
Collapse
|
4
|
Vincent PF, Young ED, Edge AS, Glowatzki E. Auditory Hair Cells and Spiral Ganglion Neurons Regenerate Synapses with Refined Release Properties In Vitro. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.05.561095. [PMID: 38076928 PMCID: PMC10705289 DOI: 10.1101/2023.10.05.561095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Ribbon synapses between inner hair cells (IHCs) and type I spiral ganglion neurons (SGNs) in the inner ear are damaged by noise trauma and with aging, causing 'synaptopathy 'and hearing loss. Co-cultures of neonatal denervated organs of Corti and newly introduced SGNs have been developed to find strategies for improving IHC synapse regeneration, but evidence of the physiological normality of regenerated synapses is missing. This study utilizes IHC optogenetic stimulation and SGN recordings, showing that newly formed IHC synapses are indeed functional, exhibiting glutamatergic excitatory postsynaptic currents. When older organs of Corti were plated, synaptic activity probed by deconvolution, showed more mature release properties, closer to the highly specialized mode of IHC synaptic transmission that is crucial for coding the sound signal. This newly developed functional assessment of regenerated IHC synapses provides a powerful tool for testing approaches to improve synapse regeneration.
Collapse
Affiliation(s)
- Philippe F.Y. Vincent
- The Center for Hearing and Balance, The Johns Hopkins School of Medicine, Baltimore, Maryland
- Department of Otolaryngology Head and Neck Surgery, The Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Eric D. Young
- The Center for Hearing and Balance, The Johns Hopkins School of Medicine, Baltimore, Maryland
- Department of Otolaryngology Head and Neck Surgery, The Johns Hopkins School of Medicine, Baltimore, Maryland
- Department of Neuroscience, The Johns Hopkins School of Medicine, Baltimore, Maryland
- Department of Biomedical Engineering, The Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Albert S.B. Edge
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts, USA
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts, USA
- Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Elisabeth Glowatzki
- The Center for Hearing and Balance, The Johns Hopkins School of Medicine, Baltimore, Maryland
- Department of Otolaryngology Head and Neck Surgery, The Johns Hopkins School of Medicine, Baltimore, Maryland
- Department of Neuroscience, The Johns Hopkins School of Medicine, Baltimore, Maryland
| |
Collapse
|
5
|
Androgens and NGF Mediate the Neurite-Outgrowth through Inactivation of RhoA. Cells 2023; 12:cells12030373. [PMID: 36766714 PMCID: PMC9913450 DOI: 10.3390/cells12030373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Steroid hormones and growth factors control neuritogenesis through their cognate receptors under physiological and pathological conditions. We have already shown that nerve growth factor and androgens induce neurite outgrowth of PC12 cells through a reciprocal crosstalk between the NGF receptor, TrkA and the androgen receptor. Here, we report that androgens or NGF induce neuritogenesis in PC12 cells through inactivation of RhoA. Ectopic expression of the dominant negative RhoA N19 promotes, indeed, the neurite-elongation of unchallenged and androgen- or NGF-challenged PC12 cells and the increase in the expression levels of βIII tubulin, a specific neuronal marker. Pharmacological inhibition of the Ser/Thr kinase ROCK, an RhoA effector, induces neuritogenesis in unchallenged PC12 cells, and potentiates the effect of androgens and NGF, confirming the role of RhoA/ROCK axis in the neuritogenesis induced by androgen and NGF, through the phosphorylation of Akt. These findings suggest that therapies based on new selective androgen receptor modulators and/or RhoA/ROCK inhibitors might exert beneficial effects in the treatment of neuro-disorders, neurological diseases and ageing-related processes.
Collapse
|
6
|
Wu Y, Meng W, Guan M, Zhao X, Zhang C, Fang Q, Zhang Y, Sun Z, Cai M, Huang D, Yang X, Yu Y, Cui Y, He S, Chai R. Pitavastatin protects against neomycin-induced ototoxicity through inhibition of endoplasmic reticulum stress. Front Mol Neurosci 2022; 15:963083. [PMID: 35992197 PMCID: PMC9381809 DOI: 10.3389/fnmol.2022.963083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
Abstract
Irreversible injury to inner ear hair cells induced by aminoglycoside antibiotics contributes to the formation of sensorineural hearing loss. Pitavastatin (PTV), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has been reported to exert neuroprotective effects. However, its role in aminoglycoside-induced hearing loss remains unknown. The objectives of this study were to investigate the beneficial effects, as well as the mechanism of action of PTV against neomycin-induced ototoxicity. We found that PTV remarkably reduced hair cell loss in mouse cochlear explants and promoted auditory HEI-OC1 cells survival after neomycin stimulation. We also observed that the auditory brainstem response threshold that was increased by neomycin was significantly reduced by pretreatment with PTV in mice. Furthermore, neomycin-induced endoplasmic reticulum stress in hair cells was attenuated by PTV treatment through inhibition of PERK/eIF2α/ATF4 signaling. Additionally, we found that PTV suppressed the RhoA/ROCK/JNK signal pathway, which was activated by neomycin stimulation in HEI-OC1 cells. Collectively, our results showed that PTV might serve as a promising therapeutic agent against aminoglycoside-induced ototoxicity.
Collapse
Affiliation(s)
- Yunhao Wu
- State Key Laboratory of Bioelectronics, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Department of Otolaryngology Head and Neck Surgery, School of Life Sciences and Technology, Zhongda Hospital, Advanced Institute for Life and Health, Southeast University, Nanjing, China
| | - Wei Meng
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, Nanjing Tongren Hospital, Southeast University, Nanjing, China
| | - Ming Guan
- Department of Otolaryngology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaolong Zhao
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Chen Zhang
- Beijing Key Laboratory of Neural Regeneration and Repair, Department of Neurobiology, Advanced Innovation Center for Human Brain Protection, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Qiaojun Fang
- State Key Laboratory of Bioelectronics, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Department of Otolaryngology Head and Neck Surgery, School of Life Sciences and Technology, Zhongda Hospital, Advanced Institute for Life and Health, Southeast University, Nanjing, China
| | - Yuhua Zhang
- State Key Laboratory of Bioelectronics, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Department of Otolaryngology Head and Neck Surgery, School of Life Sciences and Technology, Zhongda Hospital, Advanced Institute for Life and Health, Southeast University, Nanjing, China
| | - Zihui Sun
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, Nanjing Tongren Hospital, Southeast University, Nanjing, China
| | - Mingjing Cai
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, Nanjing Tongren Hospital, Southeast University, Nanjing, China
| | - Dongdong Huang
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, Nanjing Tongren Hospital, Southeast University, Nanjing, China
| | - Xuechun Yang
- Department of Otolaryngology-Head and Neck Surgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yafeng Yu
- Department of Otolaryngology, First Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Yafeng Yu,
| | - Yong Cui
- Department of Otolaryngology-Head and Neck Surgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- The Second School of Clinical Medicine, South Medical University, Guangzhou, China
- School of Medicine, South China University of Technology, Guangzhou, China
- Yong Cui,
| | - Shuangba He
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, Nanjing Tongren Hospital, Southeast University, Nanjing, China
- Shuangba He,
| | - Renjie Chai
- State Key Laboratory of Bioelectronics, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Department of Otolaryngology Head and Neck Surgery, School of Life Sciences and Technology, Zhongda Hospital, Advanced Institute for Life and Health, Southeast University, Nanjing, China
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, China
- Renjie Chai,
| |
Collapse
|
7
|
Mertsch S, Neumann I, Rose C, Schargus M, Geerling G, Schrader S. The effect of Rho Kinase inhibition on corneal nerve regeneration in vitro and in vivo. Ocul Surf 2021; 22:213-223. [PMID: 34419637 DOI: 10.1016/j.jtos.2021.08.011] [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: 05/12/2021] [Revised: 08/13/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Impairment of corneal nerves can lead to neurotrophic keratopathy accompanied with severe ocular surface damage, which due to limited treatment options, can result in severe visual deterioration. This study evaluates a possible new treatment by enhancing the corneal nerve regeneration using a Rho Kinase inhibitor (Y27632). ROCK is known to play an important role in regulating cell morphology, adhesion and motility but little is known about its role in corneal nerve regeneration. METHODS Effects of ROCK inhibition on murine peripheral nerves was assessed in single cell- and wound healing assays as well as a 3D in vitro model. Furthermore, Sholl analysis evaluating neuronal branching and life-death assays evaluating toxicity of the inhibitor were performed. An in vivo mouse model was established, with monitoring weekly corneal nerve regrowth using confocal microscopy. Additionally, corneal nerve fiber length was evaluated by immunofluorescence staining. Underlying pathways were examined by qrtPCR. RESULTS ROCK inhibition leads to a significant enhancement of fiber growth in vitro. Sholl analysis revealed a higher degree of branching of treated fibers. Cytotoxicity assay showed no influence of Y27632 on cellular survival. In vivo measurement revealed significant enhanced regeneration after injury in the treated group. QrtPCR of trigeminal ganglia confirmed ROCK knock-down as well as altered pathways. CONCLUSION The inhibition of ROCK after corneal nerve injury resulted in an enhanced regrowth of fibers in vitro and in vivo. This might be a step towards a new therapeutic concept for the treatment of impaired corneal nerves in diseases such as neurotrophic keratopathy.
Collapse
Affiliation(s)
- Sonja Mertsch
- Laboratory of Experimental Ophthalmology, Department of Ophthalmology, Pius-Hospital, Carl von Ossietzky University Oldenburg, Germany.
| | - Inga Neumann
- Laboratory of Experimental Ophthalmology, Department of Ophthalmology, University Hospital Duesseldorf, Heinrich-Heine-University, Germany
| | - Cosima Rose
- Laboratory of Experimental Ophthalmology, Department of Ophthalmology, University Hospital Duesseldorf, Heinrich-Heine-University, Germany
| | - Marc Schargus
- Laboratory of Experimental Ophthalmology, Department of Ophthalmology, University Hospital Duesseldorf, Heinrich-Heine-University, Germany; Department of Ophthalmology, Asklepios Hospital Nord-Heidberg, Hamburg, Germany
| | - Gerd Geerling
- Laboratory of Experimental Ophthalmology, Department of Ophthalmology, University Hospital Duesseldorf, Heinrich-Heine-University, Germany
| | - Stefan Schrader
- Laboratory of Experimental Ophthalmology, Department of Ophthalmology, Pius-Hospital, Carl von Ossietzky University Oldenburg, Germany
| |
Collapse
|
8
|
Kimura E, Mizutari K, Kurioka T, Kawauchi S, Satoh Y, Sato S, Shiotani A. Effect of shock wave power spectrum on the inner ear pathophysiology in blast-induced hearing loss. Sci Rep 2021; 11:14704. [PMID: 34282183 PMCID: PMC8289960 DOI: 10.1038/s41598-021-94080-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/29/2021] [Indexed: 11/10/2022] Open
Abstract
Blast exposure can induce various types of hearing impairment, including permanent hearing loss, tinnitus, and hyperacusis. Herein, we conducted a detailed investigation of the cochlear pathophysiology in blast-induced hearing loss in mice using two blasts with different characteristics: a low-frequency dominant blast generated by a shock tube and a high-frequency dominant shock wave generated by laser irradiation (laser-induced shock wave). The pattern of sensorineural hearing loss (SNHL) was low-frequency- and high-frequency-dominant in response to the low- and high-frequency blasts, respectively. Pathological examination revealed that cochlear synaptopathy was the most frequent cochlear pathology after blast exposure, which involved synapse loss in the inner hair cells without hair cell loss, depending on the power spectrum of the blast. This pathological change completely reflected the physiological analysis of wave I amplitude using auditory brainstem responses. Stereociliary bundle disruption in the outer hair cells was also dependent on the blast’s power spectrum. Therefore, we demonstrated that the dominant frequency of the blast power spectrum was the principal factor determining the region of cochlear damage. We believe that the presenting models would be valuable both in blast research and the investigation of various types of hearing loss whose pathogenesis involves cochlear synaptopathy.
Collapse
Affiliation(s)
- Eiko Kimura
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Kunio Mizutari
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan.
| | - Takaomi Kurioka
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Satoko Kawauchi
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Saitama, 359-8513, Japan
| | - Yasushi Satoh
- Department of Biochemistry, National Defense Medical College, Saitama, 359-8513, Japan
| | - Shunichi Sato
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Saitama, 359-8513, Japan
| | - Akihiro Shiotani
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| |
Collapse
|
9
|
Koizumi Y, Mizutari K, Kawauchi S, Sato S, Shiotani A, Kakehata S. Y-27632, a ROCK inhibitor, improved laser-induced shock wave (LISW)-induced cochlear synaptopathy in mice. Mol Brain 2021; 14:105. [PMID: 34217338 PMCID: PMC8254252 DOI: 10.1186/s13041-021-00819-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/28/2021] [Indexed: 11/10/2022] Open
Abstract
Recently, a pathological condition called cochlear synaptopathy has been clarified, and as a disorder of the auditory nerve synapses that occurs prior to failure of hair cells, it has been recognized as a major cause of sensorineural hearing loss. However, cochlear synaptopathy is untreatable. Inhibition of rho-associated coiled-coil containing protein kinase (ROCK), a serine-threonine protein kinase, has been reported to have neuroprotective and regenerative effects on synaptic pathways in the nervous system, including those in the inner ear. We previously demonstrated the regenerative effect of the ROCK inhibitor, Y-27632, on an excitotoxic cochlear nerve damage model in vitro. In this study, we aimed to validate the effect of ROCK inhibition on mice with cochlear synaptopathy induced by laser-induced shock wave (LISW) in vivo. After the elevation of ROCK1/2 expression in the damaged cochlea was confirmed, we administered Y-27632 locally via the middle ear. The amplitude of wave I in the auditory brainstem response and the number of synapses in the Y-27632-treated cochlea increased significantly. These results clearly demonstrate that ROCK inhibition has a promising clinical application in the treatment of cochlear synaptopathy, which is the major pathology of sensorineural hearing loss.
Collapse
Affiliation(s)
- Yutaka Koizumi
- Department of Otolaryngology-Head and Neck Surgery, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan
| | - Kunio Mizutari
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan.
| | - Satoko Kawauchi
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Saitama, 359-8513, Japan
| | - Shunichi Sato
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Saitama, 359-8513, Japan
| | - Akihiro Shiotani
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Seiji Kakehata
- Department of Otolaryngology-Head and Neck Surgery, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan.
| |
Collapse
|
10
|
Harre J, Heinkele L, Steffens M, Warnecke A, Lenarz T, Just I, Rohrbeck A. Potentiation of Brain-Derived Neurotrophic Factor-Induced Protection of Spiral Ganglion Neurons by C3 Exoenzyme/Rho Inhibitor. Front Cell Neurosci 2021; 15:602897. [PMID: 33776650 PMCID: PMC7991574 DOI: 10.3389/fncel.2021.602897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 02/19/2021] [Indexed: 11/17/2022] Open
Abstract
Preservation of the excitability of spiral ganglion neurons (SGN) may contribute to an improved speech perception after cochlear implantation. Thus, the application of exogenous neurotrophic factors such as the neurotrophin brain-derived neurotrophic factor (BDNF) to increase SGN survival in vitro and in vivo is a promising pharmacological approach in cochlear implant (CI) research. Due to the difficult pharmacokinetic profile of proteins such as BDNF, there is a quest for small molecules to mediate the survival of SGN or to increase the efficacy of BDNF. The C3 exoenzyme from Clostridium botulinum could be a potential new candidate for the protection and regeneration of SGN. Inhibition of the RhoA GTPase pathway which can be mediated by C3 is described as a promising strategy to enhance axonal regeneration and to exert pro-survival signals in neurons. Nanomolar concentrations of C3, its enzymatically inactive form C3E174Q, and a 26mer C-terminal peptide fragment covering amino acid 156–181 (C3156-181) potentiated the neuroprotective effect on SGN mediated by BDNF in vitro. The neuroprotective effect of C3/BDNF was reduced to the neuroprotective effect of BDNF alone after the treatment with wortmannin, an inhibitor of the phosphatidylinositol-3-kinase (PI3K).The exoenzyme C3 (wild-type and enzyme-deficient) and the C3 peptide fragment C3154–181 present novel biologically active compounds for the protection of the SGN. The exact underlying intracellular mechanisms that mediate the neuroprotective effect are not clarified yet, but the combination of BDNF (TrkB stimulation) and C3 exoenzyme (RhoA inhibition) can be used to protect SGN in vitro.
Collapse
Affiliation(s)
- Jennifer Harre
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Laura Heinkele
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Melanie Steffens
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Athanasia Warnecke
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Ingo Just
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Astrid Rohrbeck
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| |
Collapse
|