Mitophagy in ototoxicity.

Mitochondrial dysfunction is associated with ototoxicity, which is caused by external factors. Mitophagy plays a key role in maintaining mitochondrial homeostasis and function and is regulated by a series of key mitophagy regulatory proteins and signaling pathways. The results of ototoxicity models indicate the importance of this process in the etiology of ototoxicity. A number of recent investigations of the control of cell fate by mitophagy have enhanced our understanding of the mechanisms by which mitophagy regulates ototoxicity and other hearing-related diseases, providing opportunities for targeting mitochondria to treat ototoxicity.

Research Progress on Non-coding RNAs in Cholesteatoma of the Middle Ear.

Cholesteatoma of the middle ear is a common disease in otolaryngology that is receiving increasing attention. It is estimated that over five million people around the world have suffered from middle ear cholesteatoma. The annual incidence of middle ear cholesteatoma has been reported to be 9.2 per 100,000 in adults and 3 per 100,000 in children. Without timely discovery and intervention, cholesteatomas can become perilously large and damage intratemporal structures, causing various intracranial and extracranial complications. No practical nonsurgical treatments are currently available. Although multiple hypotheses exist, research directions have consistently focused on cell proliferation, apoptosis, and bone destruction. Non-coding RNAs (ncRNAs), especially microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), have recently received increasing attention because of their key roles in gene expression, cell cycle regulation, and the development of many diseases. Although ncRNAs are not involved in protein translation, they are abundant in the genome, with only approximately 2% of genes encoding proteins and the remaining approximately 98% encoding ncRNAs. The purpose of this review is to summarize the current state of knowledge regarding the specific role of ncRNAs in middle ear cholesteatoma.

Cisplatin-induced ototoxicity: From signaling network to therapeutic targets.

Administration of cisplatin, a common chemotherapeutic drug, has an inevitable side effect of sensorineural hearing loss. The main etiologies are stria vascularis injury, spiral ganglion degeneration, and hair cell death. Over several decades, the research scope of cisplatin-induced ototoxicity has expanded with the discovery of the molecular mechanism mediating inner ear cell death, highlighting the roles of reactive oxygen species and transport channels for cisplatin uptake into inner ear cells. Upon entering hair cells, cisplatin disrupts organelle metabolism, induces oxidative stress, and targets DNA to cause intracellular damage. Recent studies have also reported the role of inflammation in cisplatin-induced ototoxicity. In this article, we preform a narrative review of the latest reported molecular mechanisms of cisplatin-induced ototoxicity, from extracellular to intracellular. We build up a signaling network starting with cisplatin entering into the inner ear through the blood labyrinth barrier, disrupting cochlear endolymph homeostasis, and activating inflammatory responses of the outer hair cells. After entering the hair cells, cisplatin causes hair cell death via DNA damage, redox system imbalance, and mitochondrial and endoplasmic reticulum dysfunction, culminating in programmed cell death including apoptosis, necroptosis, autophagic death, pyroptosis, and ferroptosis. Based on the mentioned mechanisms, prominent therapeutic targets, such as channel-blocking drugs of cisplatin transporter, construction of cisplatin structural analogues, anti-inflammatory drugs, antioxidants, cell death inhibitors, and others, were collated. Considering the recent research efforts, we have analyzed the feasibility of the aforementioned therapeutic strategies and proposed our otoprotective approaches to overcome cisplatin-induced ototoxicity.

Herbal medicines in the treatment of tinnitus: An updated review.

Tinnitus is perception of sound in the absence of an apparent external acoustic stimulus. The condition is prevalent in adults, especially the elderly (≥65 years), and may be associated with cognitive function decline and significantly impacts on the quality of life, heralding difficulties in managing this challenging disorder. Interventions for tinnitus have been varied. However, drugs have not yet been approved for the treatment of tinnitus and there is no pharmacotherapy recommended by existing guidelines. Still, herbal medicines are used for the treatment of tinnitus in many countries, especially Gingko (G.) biloba. In the current updated literature review, we evaluated the efficacy of herbal medicines in the treatment of tinnitus by reviewing the evidence of relevant randomized controlled trials. The authors also highlight some of the issues in clinical trials of herbal medicines given that currently available evidence on herbal medicines for tinnitus is overall of insufficient quality and the conclusions from existing trials are conflicting. Nevertheless, there is a clear and urgent need for safe and effective pharmacotherapy of tinnitus.

AMPK inhibitor BML-275 induces neuroprotection through decreasing cyt c and AIF expression after transient brain ischemia.

Stroke is a major public health problem with an imperative need for a more effective and tolerated therapy. Neuroprotective therapy may be an effective therapeutic intervention for stroke. The morbidity and mortality of stroke-induced secondary brain injury is mainly caused by neuronal apoptosis, which can be executed in a caspase-dependent or apoptosis inducing factor (AIF)-dependent manner. As apoptosis is an energy-dependent process with a relative time delay, abnormal energy metabolism could be a significant and fundamental pathophysiological basis of stroke. To our knowledge, convincible evidences that AMPK inhibition exerts neuroprotection in cerebral ischemia injury via anti-apoptosis remain to be investigated. Accordingly, the aims of this study were to investigate the protective effects of AMPK inhibitor BML-275 on cerebral ischemic/reperfusion (I/R) injury and to elucidate the underlying mechanisms. Cerebral ischemia was induced by transient middle cerebral artery occlusion (tMCAO) in male C57BL/6 mice. The therapeutic effects of BML-275 were evaluated by infarct sizes, neurological scores and the proportion of apoptotic neurons after 24 h of reperfusion. The cell apoptosis markers cyt c and AIF were also evaluated. The results showed that intraperitoneally administration of BML-275 alleviate the cerebral infarction, neurological deficit and neuronal apoptosis induced by MCAO. BML-275 simultaneously induces anti-apoptosis and decreases the expression of cyt c and AIF. This study supports the hypothesis that anti-apoptosis is one of potential neuroprotective strategies for the treatment of stroke.

Dihydromyricetin Protects Against Gentamicin-Induced Ototoxicity via PGC-1α/SIRT3 Signaling in vitro.

Aminoglycoside-induced ototoxicity can have a major impact on patients' quality of life and social development problems. Oxidative stress affects normal physiologic functions and has been implicated in aminoglycoside-induced inner ear injury. Excessive accumulation of reactive oxygen species (ROS) damages DNA, lipids, and proteins in cells and induces their apoptosis. Dihydromyricetin (DHM) is a natural flavonol with a wide range of health benefits including anti-inflammatory, antitumor, and antioxidant effects; however, its effects and mechanism of action in auditory hair cells are not well understood. The present study investigated the antioxidant mechanism and anti-ototoxic potential of DHM using House Ear Institute-Organ of Corti (HEI-OC)1 auditory cells and cochlear explant cultures prepared from Kunming mice. We used gentamicin to establish aminoglycoside-induced ototoxicity models. Histological and physiological analyses were carried out to determine DHM's pharmacological effects on gentamicin-induced ototoxicity. Results showed DHM contributes to protecting cells from apoptotic cell death by inhibiting ROS accumulation. Western blotting and quantitative RT-PCR analyses revealed that DHM exerted its otoprotective effects by up-regulating levels of peroxisome proliferator activated receptor γ-coactivator (PGC)-1α and Sirtuin (SIRT)3. And the role of PGC-1α and SIRT3 in the protective effects of DHM was evaluated by pharmacologic inhibition of these factors using SR-18292 and 3-(1H-1,2,3-triazol-4-yl) pyridine, respectively, which indicated DHM's protective effect was dependent on activation of the PGC-1α/SIRT3 signaling. Our study is the first report to identify DHM as a potential otoprotective drug and provides a basis for the prevention and treatment of hearing loss caused by aminoglycoside antibiotic-induced oxidative damage to auditory hair cells.

DNA methylation biomarkers for nasopharyngeal carcinoma.

BACKGROUND: Aberrant methylation of DNA plays an important role in the pathogenesis of nasopharyngeal carcinoma (NPC). In the current study, we aimed to integrate three cohorts profile datasets to identify abnormally methylated-differentially expressed genes and pathways associated with NPC. METHODS: Data of gene expression microarrays (GSE53819, GSE412452) and gene methylation microarrays (GSE52068) obtained from the GEO database. Aberrantly methylated differentially expressed genes (DEGs) were obtained by GEO2R. The David database was utilized to perform enrichment and functional analysis regarding selected genes. To create a protein-protein interaction (PPI), STRING and Cytoscape software were utilized. The MCODE was used for module analysis of the PPI network. RESULTS: In total, 181 hypomethylation-high expression genes were identified, which were enriched in the biological mechanisms involved in the differentiation of endodermal cell, mitotic nuclear division, mitotic cell cycle process, chromosome segregation and cell cycle phase transition, etc. Pathway enrichment showed ECM-receptor interaction, PI3K-Akt signaling pathway, Focal adhesion, Protein digestion and absorption and Amoebiasis, etc. The top 3 hub genes of PPI network were FANCI, POSTN, and IFIH1. Additionally, 210 hypermethylation-low expression genes were identified, and our data revealed enrichment in biological processes including axoneme assembly, micro tubular formation, assembly of axonemal dynein complex, cilium movement and cilium organization, etc. Pathway analysis indicated enrichment in B cell receptor signaling pathway, Hematopoietic cell lineage, Leukocyte transendothelial migration, Complement and coagulation cascades and Fc gamma R-mediated phagocytosis, etc. The ZMYND10, PACRG and POU2AF1 were identified as the top three hub genes of PPI network. After validation in TCGA and GEPIA database, most hub genes remained significant. Patients with high expression of POSTN found to have shorter overall survival, while in patients with high expression of ZMYND10 and POU2AF1 longer overall survival was identified. CONCLUSIONS: The data revealed novel aberrantly methylated-differentially expressed genes and pathways in NPC by bioinformatics analysis, potentially providing novel insights for the molecular mechanisms governing NPC progression. Hub genes including FANCI, POSTN, IFIH1, ZMYND10, PACRG and POU2AF1 might serve as novel biomarkers for precision diagnosis and providing medical treatment for patient with NPC.

Association of polymorphisms in grainyhead-like-2 gene with the susceptibility to age-related hearing loss: A systematic review and meta-analysis.

OBJECTIVE: The grainyhead-like-2 (GRHL2) genetic variants were reported in age-related hearing impairment (ARHI) susceptibility in several case-control studies. However, their conclusions are conflicting; it is difficult to precisely assess the disease risk associated with the variants. Therefore we conduct the meta-analysis to discover the association of GRHL2 polymorphisms and the risk of ARHI. METHODS: A related literature search was conducted in on-line databases, such as Wanfang database, China National Knowledge Infrastructure (CNKI), EMBASE, Web of Science, and PubMed (updated to August 30, 2018). We use Review Manager 5.0 and Stata SE 12.0 software to reckon the odds radio (OR), 95% confidence interval (CI) and P value in random- or fixed-effects model according to the I2 value in the heterogeneity test. RESULTS: 2762 cases and 2321 controls in 5 articles were provided data to the meta-analysis. The pooled ORs (95% CI) of the rs10955255 polymorphism were 1.26 (1.05-1.50, P = .01), 1.33 (1.07-1.65, P = .01), and 1.32 (1.12-1.55, P = .0007) in the allele, homozygote and recessive model separately. Besides, a significant association was detected between rs1981361 in mixed population and the ARHI risk in the allele, heterozygote, and dominant genetic model respectively. Then subgroup analyses was performed by ethnicity, for rs10955255 meaningful associations were detected for the allele model, homozygote model, dominant model and recessive model in the Caucasian population but no relations in any of the 5 genetic models in Asian population. CONCLUSION: The meta-analysis indicated that the rs10955255 polymorphism could be an important risk factor for ARHI, especially in the Caucasians. The rs1981361 polymorphism may be a risk factor for ARHI in Asians. Larger scale researches are needed to further bring the consequences up to date.

Presence of Anxiety and Depression Symptoms Affects the First Time Treatment Efficacy and Recurrence of Benign Paroxysmal Positional Vertigo.

OBJECTIVES: To investigate the possible effects of anxiety and/or depression symptoms on the treatment outcomes and recurrence of benign paroxysmal positional vertigo (BPPV). METHODS: This is a retrospective study conducted at a single institution. 142 consecutive patients diagnosed with idiopathic BPPV at the Department of Otology in Shengjing Hospital of China Medical University between October 2016 and July 2017 were retrospectively reviewed. 127 patients were finally included in this study. Zung self-rating anxiety scale (SAS) and Zung self-rating depression scale (SDS) were used to evaluate the presence of anxiety and/or depression, respectively, in our BPPV patients. A significant score (at or above 50 for SAS and 53 for SDS) represents the presence of clinically significant symptoms. Two-tailed Student's t-test, χ2 test, and logistic regression analysis were used as appropriate. A p value less than 0.05 was considered statistically significant. RESULTS: The prevalence of anxiety and/or depression symptoms in BPPV patients in the present study was 49.61%. The effectiveness of the first time canalith repositioning maneuver (CRM) was 70.08%. With weekly follow-up treatments of CRM, the success rate increased to 97.64% by 1 month. The total recurrence rate at 6-month follow-up post-cure was 14.17%. Holding all other variables constant, patients with psychiatric symptoms (Relative-risk ratio: 3.160; p = 0.027) and patients with non-posterior semicircular canal (PSC) involvement (Relative-risk ratio: 7.828, p = 0.013) were more likely to experience residual dizziness (RD) even after effective CRM treatment. Psychiatric symptoms (Relative-risk ratio: 6.543; p = 0.001) and female gender (Relative-risk ratio: 4.563; p = 0.010) are risk factors for the failure of first time CRM. In addition, BPPV patients with psychiatric symptoms (Odds ratio: 9.184, p = 0.008) were significantly more likely to experience recurrences within the first 6 months after a successful maneuver. CONCLUSION: Anxiety-depression status significantly reduced the efficacy of the first time CRM and increased the risk for recurrence. Other factors, such as female gender and non-PSC involvement are also susceptible risk factors for BPPV patients to require multiple treatments and experience delayed recovery. A screening for psychiatric symptoms in BPPV patients and active treatment of these symptoms would benefit both physicians and patients in understanding and improving the prognosis of the disease and treatment options.

Sox2 haploinsufficiency primes regeneration and Wnt responsiveness in the mouse cochlea.

During development, Sox2 is indispensable for cell division and differentiation, yet its roles in regenerating tissues are less clear. Here, we used combinations of transgenic mouse models to reveal that Sox2 haploinsufficiency (Sox2haplo) increases rather than impairs cochlear regeneration in vivo. Sox2haplo cochleae had delayed terminal mitosis and ectopic sensory cells, yet normal auditory function. Sox2haplo amplified and expanded domains of damage-induced Atoh1+ transitional cell formation in neonatal cochlea. Wnt activation via ß-catenin stabilization (ß-cateninGOF) alone failed to induce proliferation or transitional cell formation. By contrast, ß-cateninGOF caused proliferation when either Sox2haplo or damage was present, and transitional cell formation when both were present in neonatal, but not mature, cochlea. Mechanistically, Sox2haplo or damaged neonatal cochleae showed lower levels of Sox2 and Hes5, but not of Wnt target genes. Together, our study unveils an interplay between Sox2 and damage in directing tissue regeneration and Wnt responsiveness and thus provides a foundation for potential combinatorial therapies aimed at stimulating mammalian cochlear regeneration to reverse hearing loss in humans.

NaHS Protects Cochlear Hair Cells from Gentamicin-Induced Ototoxicity by Inhibiting the Mitochondrial Apoptosis Pathway.

Aminoglycoside antibiotics such as gentamicin could cause ototoxicity in mammalians, by inducing oxidative stress and apoptosis in sensory hair cells of the cochlea. Sodium hydrosulfide (NaHS) is reported to alleviate oxidative stress and apoptosis, but its role in protecting aminoglycoside-induced hearing loss is unclear. In this study, we investigated the anti-oxidant and anti-apoptosis effect of NaHS in in vitro cultured House Ear Institute-Organ of Corti 1 (HEI-OC1) cells and isolated mouse cochlea. Results from cultured HEI-OC1 cells and cochlea consistently indicated that NaHS exhibited protective effects from gentamicin-induced ototoxicity, evident by maintained cell viability, hair cell number and cochlear morphology, reduced reactive oxygen species production and mitochondrial depolarization, as well as apoptosis activation of the intrinsic pathway. Moreover, in the isolated cochlear culture, NaHS was also demonstrated to protect the explant from gentamicin-induced mechanotransduction loss. Our study using multiple in vitro models revealed for the first time, the potential of NaHS as a therapeutic agent in protecting against aminoglycoside-induced hearing loss.

Silencing of Src by siRNA inhibits laryngeal carcinoma growth through the Src/PI-3 K/Akt pathway in vitro and in vivo.

This study aimed to investigate the expression, function, and possible mechanism of Src in the Hep-2 cell line. We used Src-specific small interfering RNA (siRNA) to inhibit the expression of Src in Hep-2 cells. RT-PCR and Western blot were applied to evaluate the expression level of Src after RNA interference, and the MTT assay and flow cytometry were used to observe the expression of PI-3 K and Akt. siRNA can downregulate the expression of Src in Hep-2 cells. Downregulation of Src decreased PI-3 K and Akt expression. We found that Src knockdown inhibits the proliferation of Hep-2 cells and the growth of laryngeal carcinoma in vivo. This study has demonstrated that Src participates in the regulation of apoptosis through the Src/PI-3 K/Akt signaling pathway in the Hep-2 cell line. Silencing of Src by siRNA is a viable approach in laryngeal carcinoma treatment.

[Cochlear implantation with pericanal electrode insertion technique].

OBJECTIVE: To investigate the surgical technique of the pericanal electrode insertion technique for ies cochlear implantation. METHOD: Forty cases of sensorineural deafness were subjected to the ies cochlear implants. Cochleostomy was performed through the external auditory canal with a microdrill anterior to the round window. The electrode impedance and electrically auditory brainstem responses(EABR) were tested during the operation. The X-ray photographs were taken after the operation. The cochlear implant was activated in all 40 cases 4 weeks following surgery. RESULT: All of the electrodes were inserted and all of the implants worked well. No electrode extrusions or serious surgical complications happened during postoperative observation for 6 months. CONCLUSION: The pericanal electrode insertion technique is a safe approach for ies cochlear implantation.