ELMOD3, an ARL2 GTPase-activating protein, is implicated in causing hearing impairment in humans. However, the specific role of ELMOD3 in auditory function is still far from being elucidated. In the present study, we used the CRISPR/Cas9 technology to establish an Elmod3 knockout mice line in the C57BL/6 background (hereinafter referred to as Elmod3-/- mice) and investigated the role of Elmod3 in the cochlea and auditory function. Elmod3-/- mice started to exhibit hearing loss from 2 months of age, and the deafness progressed with aging, while the vestibular function of Elmod3-/- mice was normal. We also observed that Elmod3-/- mice showed thinning and receding hair cells in the organ of Corti and much lower expression of F-actin cytoskeleton in the cochlea compared with wild-type mice. The deafness associated with the mutation may be caused by cochlear hair cells dysfunction, which manifests with shortening and fusion of inner hair cells stereocilia and progressive degeneration of outer hair cells stereocilia. Our finding associates Elmod3 deficiencies with stereocilia dysmorphologies and reveals that they might play roles in the actin cytoskeleton dynamics in cochlear hair cells, and thus relate to hearing impairment.
Pediatric middle ear cholesteatoma is an aggressive keratotic lesion caused by abnormal proliferation of keratinised squamous epithelium in the temporal bone, with the characteristics of high postoperative recurrence rate, poor hearing effect and poor quality of life. Endoscopic surgery is able to deal with the majority of pediatric middle ear cholesteatoma cases with the features of minimal trauma and wide surgical field. However, endoscopic surgical treatment still has problems in standardization. In order to facilitate the development of endoscopic surgery for pediatric middle ear cholesteatoma, experts of the Endoscopic Ear Surgery Expert Committee and the Youth Committee of the Otorhinolaryngology Professional Committee, Chinese Association of Integrative Medicine discussed and formulated recommendations for the selection of endoscopic surgical and functional reconstruction methods of pediatric middle ear cholesteatoma based on the classification of cholesteatoma location in line with the clinical research results and diagnosis and treatment experience at home and abroad, aiming to provide guidance for the development of endoscopic surgery in pediatric setting.
ABSTRACT Objectives The first purpose of this study was to ascertain the distribution of unilateral Ménière's disease (MD) clinical subgroups in China and compare with the population reported in Europe and the United States. The second purpose was to investigate the effectiveness in different clinical phenotypes. Methods Participants were categorised into one of five subtypes using a previously reported classification scheme based on cluster analysis. The distribution and clinical characteristics were analysed and compared with the two cohorts reported in Europe and the United States. Participants were followed up to observe the therapeutic effectiveness over a 2‐year period. Results A total of 245 patients diagnosed with UMD were enrolled in the study, with 84 of these participants providing complete and detailed follow‐up data. All of the unilateral MD patients were accurately classified: 58.0% were classic MD, 25.7% were delayed MD, 1.2% was familial MD, 12.7% were sporadic MD with migraine and 2.4% were autoimmune MD. Our findings revealed a significant difference in the distribution between this cohort and the European cohort. Follow‐up assessments revealed worse vertigo control rate in the patients with migraine compared to the classical MD (50.0% vs. 82.6%, p = 0.034). Conclusion The distribution of unilateral MD subtypes in this Chinese population differs from that in the European population, and the therapeutic effectiveness varies across subtypes in this cohort. Our study highlights the importance of the clinical heterogeneity in unilateral MD, and further studies are needed to identify the optimal interventions for specific subgroups.
Objective:To investigate the clinical chacteration and molecular pathology of Waardenburg syndrome type 2 in seven families, and provide genetic diagnosis and hereditary counseling for family members. Method:Clinical data of seven families with WS2(14 patients)were collected. Peripheral blood samples of the probands and related family members were collected and genomic DNA was extracted. The coding sequences of microphthalmia associated transcription factor (MITF), sex-determining region Y-box 10(SOX10), snail family zinc finger 2 (SNAI2) and endothelin receptor type B(EDNRB)were analyzed by polymerase chain reaction and DNA sequencing. Then the raw data was analyzed. Result:The most common manifestations of WS2 are sensorineural hearing loss(10/14,71.4%), freckle(7/14, 50.0%),heterochromia iridis(6/14, 42.9%) and premature greying(5/14,35.7%). All the deafness phenotype is congenital, bilateral profound sensorineural hearing loss. Freckles phenotype is different from cutaneous pigment abnormalities of WS in Westerners. The heterozygous mutation, c.328C>T in exon 3 of the MITF gene was detected in the proband and all patients of pedigree 2. However, no pathological mutation of the relevant genes (SOX10,SNAI2 and EDNRB) was detected in other pedigrees. Conclusion:There are obvious variations in clinical features of WS, while freckles may be a special subtype of cutaneous pigment disturbances. The MITF gene mutation, R110X,is therefore considered the disease causing mutation in pedigree WS02.However, there are novel disease causing genes or copy number variations in Waardenburg syndrome type 2, which require further research.
Abstract Meniere's disease (MD) is an inner ear disease characterized by endolymphatic hydrops (EH). Maintaining a regular daily routine is crucial for MD patients. However, the relationship between circadian rhythms and MD remains unclear. Therefore, we investigated the effect of circadian rhythm on endolymphatic hydrops and its underlying mechanisms. Mice with endolymphatic hydrops were subjected to chronic jet lag (CJL) conditions to simulate the MD patients under circadian rhythm disruptions. We assessed whether this disruption would exacerbate inner ear damage with endolymphatic hydrops. RNA‐seq of the inner ear and bioinformatic analysis were performed. Then, the expression of PER2, AQP2, AQP4, AQP5, and BDNF were assessed, and the morphological changes were evaluated in the inner ear. Our findings showed circadian rhythm disruption affected the cochlear internal clock genes in the inner ear, particularly in mice with EH. EH mice under CJL conditions exhibited exacerbated hearing impairment and an increased severity of EH. GO enrichment analysis revealed that the regulation of fluid homeostasis and neurotransmitter release at synapses were significantly enriched. Disruption of circadian rhythms disturbed the expression pattern of PER2, reduced BDNF levels, and affected the expression of aquaporins in the cochlea. Moreover, the disruption of circadian rhythm compromised inner hair cell synapses and auditory nerve fibers. This study indicated that disruption of circadian rhythms may exacerbate inner ear damage in endolymphatic hydrops mice by affecting the aquaporins and compromising synapses and auditory nerves in the inner ear. BDNF and PER2 may play a central role in these pathophysiological processes.
ABCC1 gene is expressed in various tissues and organs of the human body, and can transport substrates including drugs, heavy metals, toxic substances and organic anions. Previous research on ABCC1 gene has mostly focused on tumor multidrug resistance. Recently, ABCC1 has been proposed as a candidate gene for hereditary hearing impairment, which has attracted much attention. ABCC1-associated deafness may be related to its role in biological barriers. This article has summarized recent progress in the study of the role of ABCC1 in the blood-testis barrier, placental barrier, blood-brain barrier, blood-labyrinth barrier, which may provide insight into its biological functions.