Ferrostatin-1 protects auditory hair cells from cisplatin-induced ototoxicity in vitro and in vivo.

Cisplatin is used in a wide variety of malignancies, but cisplatin-induced ototoxicity remains a major issue in clinical practice. Experimental evidence indicates that ferroptosis plays a key role in mediating the unwanted cytotoxicity effect caused by cisplatin. However, the role of ferroptosis in cisplatin-induced ototoxicity requires elucidation. Ferrostatin-1 (Fer-1) was identified as a potent inhibitor of ferroptosis and radical-trapping antioxidant with its ability to reduce the accumulation of lipid peroxides and chain-carrying peroxyl radicals. In the current study, we investigated the effects of Fer-1 in cisplatin-induced ototoxicity in in vitro, ex vivo, and in vivo models. We found, for the first time that Fer-1 efficiently alleviated cisplatin-induced cytotoxicity in HEI-OC1 cells via a concentration-dependent manner. Furthermore, Fer-1 mitigated cisplatin cytotoxicity in transgenic zebrafish sensory hair cells. In HEI-OC1 cells, Fer-1 pretreatment not only drastically reduced the generation of intracellular reactive oxygen species but also remarkably decreased lipid peroxidation levels induced by cisplatin. This was not only ascribed to the inhibition of 4-hydroxynonenal, the final product of lipid peroxides, but also to the promotion of glutathione peroxidase 4, the protein marker of ferroptosis. MitoTracker staining and transmission electron microscopy of mitochondrial morphology suggested that in HEI-OC1 cells, Fer-1 can effectively abrogate mitochondrial damage resulting from the interaction with cisplatin. In addition, Fer-1 pretreatment of cochlear explants substantially protected hair cells from cisplatin-induced damage. Therefore, our results demonstrated that ferroptosis might be involved in cisplatin ototoxicity. Fer-1 administration mitigated cisplatin-induced hair cell damage, further investigations are required to elucidate the molecular mechanisms of its otoprotective effect.

Characterization of the Transcriptome of Hair Cell Regeneration in the Neonatal Mouse Utricle.

BACKGROUND/AIMS: Hearing and balance deficits are mainly caused by loss of sensory inner ear hair cells. The key signals that control hair cell regeneration are of great interest. However, the molecular events by which the cellular signals mediate hair cell regeneration in the mouse utricle are largely unknown. METHODS: In the present study, we investigated gene expression changes and related molecular pathways using RNA-seq and qRT-PCR in the newborn mouse utricle in response to neomycin-induced damage. RESULTS: There were 302 and 624 genes that were found to be up-regulated and down-regulated in neomycin-treated samples. GO and KEGG pathway analyses of these genes revealed many deregulated cellular components, molecular functions, biological processes and signaling pathways that may be related to hair cell development. More importantly, the differentially expressed genes included 9 transcription factors from the zf-C2H2 family, and eight of them were consistently down-regulated during hair cell damage and subsequent regeneration. CONCLUSION: Our results provide a valuable source for future studies and highlighted some promising genes, pathways or processes that may be useful for therapeutic applications.

Tinnitus Related to Forceful Eyelid Closure: A Case Report.

Tinnitus is a common complaint in the clinical setting and can be classified into sensorineural and objective tinnitus. The sources of objective tinnitus may either come from para-auditory structures, such as myogenic or vascular structures, or the middle ear muscles. One type of objective tinnitus of muscular origin is known as forceful eyelid closure syndrome (FECS). We present an additional case of a 22-year-old woman with unilateral FECS. The auricles and external auditory canals were normal bilaterally; we examined her tympanic membrane under an endoscope, the left tympanic membrane was retracted simultaneously with the closure of her eyelids. Both tympanograms were of type A. However, small cut trace associated with tympanic membrane movement were obtained during blinking. The patient was managed by behavioral therapy and medication treatment conservatively, and the condition became well-controlled. Here, we present this rare case and review the literature.

Novel Application of Eupatilin for Effectively Attenuating Cisplatin-Induced Auditory Hair Cell Death via Mitochondrial Apoptosis Pathway.

Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is a pharmacologically active flavone that has been isolated from a variety of medicinal plants and possesses a number of pharmacological properties. This study evaluates the antioxidant and antiapoptotic effects of eupatilin on cisplatin-induced ototoxicity using in vitro and in vivo models including HEI-OC1 cells, cochlear hair cells, and zebrafish. Employing a CCK8 assay and Annexin V-FITC/PI double staining, we found that eupatilin significantly alleviated cisplatin-induced apoptosis and increased hair cell viability. The level of reactive oxygen species (ROS) was evaluated by CellROX green and MitoSOX Red staining. The results showed that eupatilin possesses antioxidant activity. MitoTracker Red staining indicated that eupatilin remarkably decreased mitochondrial damage. Furthermore, we demonstrated that eupatilin protects hair cells from cisplatin-induced damage. Mechanistic studies in cisplatin-induced HEI-OC1 cells revealed that eupatilin promoted Bcl-2 expression, downregulated Bax expression, reversed the increase in caspase-3 and PARP activity, and reduced the expression of phosphorylated p38 and JNK. Our data suggest a novel role for eupatilin as a protective agent against ototoxic drug-induced hair cell apoptosis by inhibiting ROS generation and modulating mitochondrial-related apoptosis.

Genetics and the Individualized Therapy of Vestibular Disorders.

Background: Vestibular disorders (VDs) are a clinically divergent group of conditions that stem from pathology at the level of the inner ear, vestibulocochlear nerve, or central vestibular pathway. No etiology can be identified in the majority of patients with VDs. Relatively few families have been reported with VD, and so far, no causative genes have been identified despite the fact that more than 100 genes have been identified for inherited hearing loss. Inherited VDs, similar to deafness, are genetically heterogeneous and follow Mendelian inheritance patterns with all modes of transmission, as well as multifactorial inheritance. With advances in genetic sequencing, evidence of familial clustering in VD has begun to highlight the genetic causes of these disorders, potentially opening up new avenues of treatment, particularly in Meniere's disease and disorders with comorbid hearing loss, such as Usher syndrome. In this review, we aim to present recent findings on the genetics of VDs, review the role of genetic sequencing tools, and explore the potential for individualized medicine in the treatment of these disorders. Methods: A search of the PubMed database was performed for English language studies relevant to the genetic basis of and therapies for vestibular disorders, using search terms including but not limited to: "genetics," "genomics," "vestibular disorders," "hearing loss with vestibular dysfunction," "individualized medicine," "genome-wide association studies," "precision medicine," and "Meniere's syndrome." Results: Increasing numbers of studies on vestibular disorder genetics have been published in recent years. Next-generation sequencing and new genetic tools are being utilized to unearth the significance of the genomic findings in terms of understanding disease etiology and clinical utility, with growing research interest being shown for individualized gene therapy for some disorders. Conclusions: The genetic knowledge base for vestibular disorders is still in its infancy. Identifying the genetic causes of balance problems is imperative in our understanding of the biology of normal function of the vestibule and the disease etiology and process. There is an increasing effort to use new and efficient genetic sequencing tools to discover the genetic causes for these diseases, leading to the hope for precise and personalized treatment for these patients.

[Analysis of reduction effect of the evoked nystagmus in the non-affect side during Dix-Hallpike or Roll-test in unilateral posterior semicircular canal benign paroxysmal positional vertigo].

Objective:Comparative analysis of the reduction effect of the evoked nystagmus in the non-affect side during Dix-Hallpike（D-H） or Roll-test in unilateral posterior semicircular canal benign paroxysmal positional vertigo（PC-BPPV） and PC-BPPV without above evoked nystagmus. Method:Retrospective analysis of 210 patients diagnosed with unilateral PC-BPPV by G-Force BPPV CRP system was made. Among them, 18 patients exhibited positive nystagmus only when the non-affected side was stimulated by D-H test（Group A）, 30 was evoked only when stimulated by Roll-test（Group B）, 26 was evoked when stimulated by both Roll-test and the non-affected side D-H test（Group C）, 136 without nystagmus in the above positions（Group D）. All the patients were diagnosed by G-Force BPPV and were treated through simulative Epley or Semont CRP. Compare the reduction effect among the groups. Result:At the first time ,the reduction effect of nystagmus in Group D was superior to those in Group A and Group C（P<0.05）. There was no difference between Group D and Group B（P>0.05）. The difference between Group A and Group C was also non-significant（P>0.05）. The average CRP times of the four groups（CRP until nystagmus disappeared or no longer alleviated） were 1.44±0.63（Group A）, 1.46±0.65（Group B）, 1.52±0.87（Group C） and 1.48±0.73（Group D）respectively. There were no statistic difference between four groups（P>0.05）. The differences of final reduction effect between groups were the same as those at the first time. Conclusion:The first time reduction effect was less effective when nystagmus evoked the non-affect side during D-H test in unilateral PC-BPPV, while it might be irrelevant to the nystagmus evoked only in Roll-test. Although the times of CRP were similar among the groups, the final reduction effect of groups with nystagmus evoked the non-affect side during D-H was poorer.

Engineering cell signaling using tunable CRISPR-Cpf1-based transcription factors.

The catalytically dead Cpf1 endonuclease from Acidaminococcus sp. BV3L6 (dAsCpf1) has been used to construct effective transcriptional repressors in bacteria and plants. However, it is still unclear if dAsCpf1 can function in human cells as a transcriptional regulator or a signal conductor. Here, we repurpose the dAsCpf1 system in human cells for a variety of functions, including the activation or repression of gene transcription. Moreover, we construct programmable ligand-controlled dAsCpf1 systems either by coupling crRNAs with engineered riboswitches or by fusing dAsCpf1 proteins with G protein-coupled receptors. These generalizable approaches allow us to regulate the transcription of endogenous genes in response to diverse classes of ligands, thus constructing artificial signaling pathways with rewired cellular input-output behaviors. The systems exhibit signal amplification, an important feature in cell signaling, when multiple crRNAs are processed from a single transcript. The results provide a robust and efficient platform for engineering customized cell signaling circuits.

[Treatment of infection in posterior tympani cavity during surgical procedures of otitis media].

OBJECTIVE: Analyse the effect of the treatment of infection in posterior tympani cavity in 168 cases with chronic otitis media. METHOD: Infection was eliminated in posterior tympani cavity of all 168 cases after surgical procedures of otitis media, and 102 tympanoplasty with autoplastic bone were operated in all cases. 22 tympanoplasty were operated without mastoidectomy, 53 with transmastoid approach, 27 with mastoidectomy and tympanoplasty. RESULT: All cases were followed up for more than one year. 160 cases were cured, the effective rate was 95% and no recurrence appeared except for 8 cases. The average threshold of hearing improvement of 87 cases > 15 dB, the effective rate was 85%. CONCLUSION: To eliminate infection, the exploratory surgery of posterior tympani cavity should be done during surgical procedures of otitis media, for improving the effect of the treatment of otitis media.

[The value of loop-mediated isothermal amplification method for rapid diagnosis of EBV DNA].

OBJECTIVE: To establish a rapid method for EBV detection with loop-mediated isothermal amplification (LAMP), and to make it as a clue for early diagnosis of nasopharyngeal carcinoma cancer. METHOD: EBV DNA was fast extracted from samples after boiling, while the whole detection will be finished within an hour with specific amplification of EBV gene by LAMP. RESULT: High specificity was shown from EBV detection of 33 clinical samples. Comparing with PCR, LAMP is more simple and convenient to perform under isothermal conditions, and require no special apparatus, thus, it is more economical and practical. CONCLUSION: LAMP analysis of EBV may be an efficient and easy way for clinical diagnosis of nasopharyngeal carcinoma.