scholarly journals Y-27632, a ROCK inhibitor, improved laser-induced shock wave (LISW)-induced cochlear synaptopathy in mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yutaka Koizumi ◽  
Kunio Mizutari ◽  
Satoko Kawauchi ◽  
Shunichi Sato ◽  
Akihiro Shiotani ◽  
...  
Keyword(s):  
Shock Wave ◽  
Hearing Loss ◽  
Protein Kinase ◽  
Sensorineural Hearing Loss ◽  
Pathological Condition ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Rock Inhibitor ◽  
Brainstem Response ◽  
Rock Inhibition

AbstractRecently, 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.

scholarly journals Y-27632, a ROCK Inhibitor, Improved Laser-induced Shock Wave (LISW)-induced Cochlear Synaptopathy in Mice

2021 ◽  
Author(s):  
Yutaka Koizumi ◽  
Kunio Mizutari ◽  
Satoko Kawauchi ◽  
Shunichi Sato ◽  
Akihiro Shiotani ◽  
...  
Keyword(s):  
Shock Wave ◽  
Hearing Loss ◽  
Protein Kinase ◽  
Sensorineural Hearing Loss ◽  
Pathological Condition ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Rock Inhibitor ◽  
Brainstem Response ◽  
Rock Inhibition

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.

scholarly journals Prevention of acquired sensorineural hearing loss in mice by in vivo Htra2 gene editing

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xi Gu ◽  
Daqi Wang ◽  
Zhijiao Xu ◽  
Jinghan Wang ◽  
Luo Guo ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Protective Effect ◽  
Hair Cell ◽  
Sensorineural Hearing Loss ◽  
Auditory Brainstem Response ◽  
Gene Editing ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Brainstem Response

Abstract Background Aging, noise, infection, and ototoxic drugs are the major causes of human acquired sensorineural hearing loss, but treatment options are limited. CRISPR/Cas9 technology has tremendous potential to become a new therapeutic modality for acquired non-inherited sensorineural hearing loss. Here, we develop CRISPR/Cas9 strategies to prevent aminoglycoside-induced deafness, a common type of acquired non-inherited sensorineural hearing loss, via disrupting the Htra2 gene in the inner ear which is involved in apoptosis but has not been investigated in cochlear hair cell protection. Results The results indicate that adeno-associated virus (AAV)-mediated delivery of CRISPR/SpCas9 system ameliorates neomycin-induced apoptosis, promotes hair cell survival, and significantly improves hearing function in neomycin-treated mice. The protective effect of the AAV–CRISPR/Cas9 system in vivo is sustained up to 8 weeks after neomycin exposure. For more efficient delivery of the whole CRISPR/Cas9 system, we also explore the AAV–CRISPR/SaCas9 system to prevent neomycin-induced deafness. The in vivo editing efficiency of the SaCas9 system is 1.73% on average. We observed significant improvement in auditory brainstem response thresholds in the injected ears compared with the non-injected ears. At 4 weeks after neomycin exposure, the protective effect of the AAV–CRISPR/SaCas9 system is still obvious, with the improvement in auditory brainstem response threshold up to 50 dB at 8 kHz. Conclusions These findings demonstrate the safe and effective prevention of aminoglycoside-induced deafness via Htra2 gene editing and support further development of the CRISPR/Cas9 technology in the treatment of non-inherited hearing loss as well as other non-inherited diseases.

scholarly journals Diagnostic Yield of MRI for Sensorineural Hearing Loss – An Audit

2020 ◽  
Vol 47 (5) ◽  
pp. 656-660
Author(s):  
Helen Wong ◽  
Yaw Amoako-Tuffour ◽  
Khunsa Faiz ◽  
Jai Jai Shiva Shankar
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Diagnostic Yield ◽  
Internal Auditory Canal ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Vestibular Evoked Myogenic Potentials ◽  
Clinical Indication ◽  
Presenting Symptoms ◽  
Brainstem Response

ABSTRACT:Purpose:Contrast-enhanced magnetic resonance imaging (CEMRI) of the head is frequently employed in investigations of sensorineural hearing loss (SNHL). The yield of these studies is perceptibly low and seemingly at odds with the aims of wise resource allocation and risk reduction within the Canadian healthcare system. The purpose of our study was to audit the use and diagnostic yield of CEMRI for the clinical indication of SNHL in our institution and to identify characteristics that may be leveraged to improve yield and optimize resource utilization.Materials and methods:The charts of 500 consecutive patients who underwent CEMRI of internal auditory canal for SNHL were categorized as cases with relevant positive findings on CEMRI and those without relevant findings. Demographics, presenting symptoms, interventions and responses, ordering physicians, and investigations performed prior to CEMRI testing were recorded. Chi-squared test and t-test were used to compare proportions and means, respectively.Results:CEMRI studies revealed relevant findings in 20 (6.2%) of 324 subjects meeting the inclusion criteria. Pre-CEMRI testing beyond audiometry was conducted in 35% of those with relevant positive findings compared to 7.3% of those without (p < 0.001). Auditory brainstem response/vestibular-evoked myogenic potentials were abnormal in 35% of those with relevant CEMRI findings compared to 6.3% of those without (p < 0.001).Conclusion:CEMRI is a valuable tool for assessing potential causes of SNHL, but small diagnostic yield at present needs justification for contrast injection for this indication. Our findings suggest preferred referral from otolaryngologists exclusively, and implementation of a non-contrast MRI for SNHL may be a better diagnostic tool.

Analysis of Click and Swept-Tone Auditory Brainstem Response Results for Moderate and Severe Sensorineural Hearing Loss

2020 ◽  
Vol 25 (6) ◽  
pp. 336-344
Author(s):  
Jingqian Tan ◽  
Jia Luo ◽  
Xin Wang ◽  
Yanbing Jiang ◽  
Xiangli Zeng ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Auditory Brainstem Response ◽  
Basilar Membrane ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Control Group ◽  
Hearing Sensitivity ◽  
Brainstem Response ◽  
Frequency Components

<b><i>Introduction:</i></b> Auditory brainstem response (ABR) is one of the commonly used methods in clinical settings to evaluate the hearing sensitivity and auditory function. The current ABR measurement usually adopts click sound as the stimuli. However, there may be partial ABR amplitude attenuation due to the delay characteristics of the cochlear traveling wave along the basilar membrane. To solve that problem, a swept-tone method was proposed, in which the show-up time of different frequency components was adjusted to compensate the delay characteristics of the cochlear basilar membrane; therefore, different ABR subcomponents of different frequencies were synchronized. <b><i>Methods:</i></b> The normal hearing group, moderate sensorineural hearing loss group, and severe sensorineural hearing loss group underwent click ABR and swept-tone ABR with different stimulus intensities. The latencies and amplitudes of waves I, III, and V in 2 detections were recorded. <b><i>Results:</i></b> It was found that the latency of each of the recorded I, III, and V waves detected by swept-tone ABR was shorter than that by click ABR in both the control group and experimental groups. In addition, the amplitude of each of the recorded I, III, and V waves, except V waves under 60 dB nHL in the moderate sensorineural hearing loss group, detected by swept-tone ABR was larger than that by click ABR. The results also showed that the swept-tone ABR could measure the visible V waves at lower stimulus levels in the severe sensorineural hearing loss group. <b><i>Conclusion:</i></b> Swept-tone improves the ABR waveforms and helps to obtain more accurate threshold to some extent. Therefore, the proposed swept-tone ABR may provide a new solution for better morphology of ABR waveform, which can help to make more accurate diagnosis about the hearing functionality in the clinic.

scholarly journals Audiological findings of a patient with H syndrome: case report

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Diala Hussein ◽  
Büşra Altın ◽  
Münir Demir Bajin
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Hearing Aids ◽  
Auditory Brainstem Response ◽  
Pure Tone Audiometry ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Brainstem Response ◽  
The Right

Abstract Background H syndrome is an autosomal recessive disorder caused by mutations in SLC29A3. Hyperpigmentation, hypertrichosis, hyperglycemia, and hearing loss are some characteristics of this disorder, and it has a prevalence of < 1/1000. The aim of this report is to spread awareness among otologists, audiologists, and pediatricians about this syndrome and its audiological features. Case presentation An 8-year-old male with a diagnosed H syndrome registered to our clinic with a complaint of hearing loss. The patient was diagnosed with hearing loss in a different clinic using only the air-conducted click auditory brainstem response test which showed wave V at 60 dB nHL for the right ear and at 80 dB nHL for the left ear. The initially performed pure tone audiometry (PTA) test in our clinic revealed a bilateral asymmetric hearing loss with a moderate sensorineural hearing loss in the right ear and a profound mixed hearing loss in the left ear. The performed air conducted click auditory brainstem response (ABR) result showed wave V at 55 dB nHL for the right ear and at 70 dB nHL for the left ear. Then, the repeated PTA test revealed a mild-severe sensorineural sloping hearing loss in the right ear and a severe sensorineural hearing loss in the left ear. Conclusion Although hearing thresholds in H syndrome could be within normal limits in some patients, sensorineural hearing loss is an important characteristic feature for this syndrome. Sensorineural hearing loss could be progressive or of sudden onset and ranges from mild to profound. Thus, it must be taken into consideration to apply the audiological follow-up regularly and paying attention to the patient’s complaints; also, a regular follow-up for language development of children with H syndrome and for the hearing aids is advised.

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