Otology
Abstract
Usher syndrome type 1F (USH1F), resulting from mutations in the protocadherin-15 (PCDH15) gene, is characterized by congenital lack of hearing and balance, and progressive blindness in the form of retinitis pigmentosa. In this study, we explore an approach for USH1F gene therapy, exceeding the single AAV packaging limit by employing a dual adeno-associated virus (AAV) strategy to deliver the full-length PCDH15 coding sequence. We demonstrate the efficacy of this strategy in mouse USH1F models, effectively restoring hearing and balance in these mice. Importantly, our approach also proves successful in expressing PCDH15 protein in clinically relevant retinal models, including human retinal organoids and non-human primate retina, showing efficient targeting of photoreceptors and proper protein expression in the calyceal processes. This research represents a major step toward advancing gene therapy for USH1F and the multiple challenges of hearing, balance, and vision impairment.
Authors
Maryna V. Ivanchenko, Daniel M. Hathaway, Eric M. Mulhall, Kevin TA Booth, Mantian Wang, Cole W. Peters, Alex J. Klein, Xinlan Chen, Yaqiao Li, Bence György, David P. Corey
Abstract
The sensory cells that transduce the signals for hearing and balance are highly specialized mechanoreceptors called hair cells that reside in the sensory epithelia of the inner ear. Loss of hair cells from toxin exposure and age can cause balance disorders and is essentially irreversible due to the inability of mammalian vestibular organs to regenerate physiologically active hair cells. Here, we show substantial regeneration of hair cells in a mouse model of vestibular damage by treatment with a combination of glycogen synthase kinase 3β and histone deacetylase inhibitors. The drugs stimulated supporting cell proliferation and differentiation into hair cells. The new hair cells were reinnervated by vestibular afferent neurons, rescuing otolith function by restoring head translation-evoked otolith afferent responses and vestibuloocular reflexes. Drugs that regenerate hair cells thus represent a potential therapeutic approach to the treatment of balance disorders.
Authors
Hanae Lahlou, Hong Zhu, Wu Zhou, Albert S.B. Edge
Abstract
Regulation of tumoral PD-L1 expression is critical to advancing our understanding of tumor immune evasion and the improvement of existing antitumor immunotherapies. Herein, we describe a CRISPR-based screening platform and identified ATXN3 as a positive regulator for PD-L1 transcription. TCGA database analysis revealed a positive correlation between ATXN3 and CD274 in more than 80% of human cancers. ATXN3-induced Pd-l1 transcription was promoted by tumor microenvironmental factors, including the inflammatory cytokine IFN-γ and hypoxia, through protection of their downstream transcription factors IRF1, STAT3, and HIF-2α. Moreover, ATXN3 functioned as a deubiquitinase of the AP-1 transcription factor JunB, indicating that ATNX3 promotes PD-L1 expression through multiple pathways. Targeted deletion of ATXN3 in cancer cells largely abolished IFN-γ– and hypoxia-induced PD-L1 expression and consequently enhanced antitumor immunity in mice, and these effects were partially reversed by PD-L1 reconstitution. Furthermore, tumoral ATXN3 suppression improved the preclinical efficacy of checkpoint blockade antitumor immunotherapy. Importantly, ATXN3 expression was increased in human lung adenocarcinoma and melanoma, and its levels were positively correlated with PD-L1 as well as its transcription factors IRF1 and HIF-2α. Collectively, our study identifies what we believe to be a previously unknown deubiquitinase, ATXN3, as a positive regulator for PD-L1 transcription and provides a rationale for targeting ATXN3 to sensitize checkpoint blockade antitumor immunotherapy.
Authors
Shengnan Wang, Radhika Iyer, Xiaohua Han, Juncheng Wei, Na Li, Yang Cheng, Yuanzhang Zhou, Qiong Gao, Lingqiang Zhang, Ming Yan, Zhaolin Sun, Deyu Fang
Abstract
BACKGROUND. The heterogeneity of tinnitus is thought to underlie the lack of objective diagnostic measures. METHODS. Longitudinal data from 20,349 participants of the Swedish Longitudinal Occupational Survey of Health (SLOSH) cohort from 2008 to 2018 was used to understand the dynamics of transition between occasional and constant tinnitus. The second part of the study included electrophysiological data from 405 participants of the Swedish Tinnitus Outreach Project (STOP) cohort. RESULTS. We determined that with increasing frequency of the occasional perception of self-reported tinnitus, the odds of reporting constant tinnitus after 2 years increases from 5 for previous tinnitus (sometimes) to 30 for previous tinnitus (often). When previous tinnitus was reported to be constant, the odds of reporting it as constant after 2 years rose to 603, suggesting that once transitioned to constant tinnitus, the likelihood of tinnitus to persist was much greater. Auditory brainstem responses (ABRs) from subjects reporting non-tinnitus (controls), occasional tinnitus, and constant tinnitus show that wave V latency increased in constant tinnitus when compared to occasional tinnitus or non-tinnitus. The ABR from occasional tinnitus was indistinguishable from that of the non-tinnitus controls. CONCLUSIONS. Our results support the hypothesis that the transition from occasional to constant tinnitus is accompanied by neuronal changes in the midbrain leading to a persisting tinnitus, which is then less likely to remit. TRIAL REGISTRATION. Not applicable FUNDING. This study was supported by the GENDER-Net Co-Plus Fund (GNP-182), the European Union’s Horizon 2020 Grant No. 848261 (UNITI) and No. 722046 (ESIT).
Authors
Niklas K. Edvall, Golbarg Mehraei, Martin Claeson, Andra Lazar, Jan Bulla, Constanze Leineweber, Inger Uhlén, Barbara Canlon, Christopher R. Cederroth
Abstract
BACKGROUND Cisplatin is widely used to treat adult and pediatric cancers. It is the most ototoxic drug in clinical use, resulting in permanent hearing loss in approximately 50% of treated patients. There is a major need for therapies that prevent cisplatin-induced hearing loss. Studies in mice suggest that concurrent use of statins reduces cisplatin-induced hearing loss.METHODS We examined hearing thresholds from 277 adults treated with cisplatin for head and neck cancer. Pretreatment and posttreatment audiograms were collected within 90 days of initiation and completion of cisplatin therapy. The primary outcome measure was a change in hearing as defined by the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE).RESULTS Among patients on concurrent atorvastatin, 9.7% experienced a CTCAE grade 2 or higher cisplatin-induced hearing loss compared with 29.4% in nonstatin users (P < 0.0001). A mixed-effect model analysis showed that atorvastatin use was significantly associated with reduced cisplatin-induced hearing loss (P ≤ 0.01). An adjusted odds ratio (OR) analysis indicated that an atorvastatin user is 53% less likely to acquire a cisplatin-induced hearing loss than a nonstatin user (OR = 0.47; 95% CI, 0.30–0.78). Three-year survival rates were not different between atorvastatin users and nonstatin users (P > 0.05).CONCLUSIONS Our data indicate that atorvastatin use is associated with reduced incidence and severity of cisplatin-induced hearing loss in adults being treated for head and neck cancer.TRIAL REGISTRATION ClinicalTrials.gov identifier NCT03225157.FUNDING Funding was provided by the Division of Intramural Research at the National Institute on Deafness and Other Communication Disorders (1 ZIA DC000079, ZIA DC000090).
Authors
Katharine A. Fernandez, Paul Allen, Maura Campbell, Brandi Page, Thomas Townes, Chuan-Ming Li, Hui Cheng, Jaylon Garrett, Marcia Mulquin, Anna Clements, Deborah Mulford, Candice Ortiz, Carmen Brewer, Judy R. Dubno, Shawn Newlands, Nicole C. Schmitt, Lisa L. Cunningham
Abstract
Molecular mechanisms governing the development of mammalian cochlea, the hearing organ, remain largely unknown. Through genome sequencing in three subjects from two families with non-syndromic cochlear aplasia, we identified homozygous 221 KB and 338 KB deletions in a non-coding region on chromosome 8 with an ~200 KB overlapping section. Genomic location of the overlapping deleted region was starting from ~350 KB downstream of GDF6. Otic lineage cells differentiated from induced pluripotent stem cells derived from an affected individual show reduced expression of GDF6 compared to control cells. A mouse knock-out of Gdf6 reveals cochlear aplasia closely resembling the human phenotype. We conclude that GDF6 plays a necessary role in early cochlear development controlled by cis-regulatory elements located within ~500 KB region of the genome in humans and that its disruption leads to deafness due to cochlear aplasia.
Authors
Guney Bademci, Clemer Abad, Filiz Basak Cengiz, Serhat Seyhan, Armagan Incesulu, Shengru Guo, Suat Fitoz, Emine Ikbal Atli, Nicholas C. Gosstola, Selma Demir, Brett M. Colbert, Gozde Cosar Seyhan, Claire J. Sineni, Duygu Duman, Hakan Gurkan, Cynthia Casson Morton, Derek M. Dykxhoorn, Katherina Walz, Mustafa Tekin
Abstract
Hearing loss is a significant public health concern, affecting over 250 million people worldwide. Both genetic and environmental etiologies are linked to hearing loss, but in many cases the underlying cellular pathophysiology is not well understood, highlighting the importance of further discovery. We found that inactivation of the gene, Tmtc4 (transmembrane and tetratricopeptide repeat 4), which was broadly expressed in the mouse cochlea, caused acquired hearing loss in mice. Our data showed Tmtc4 enriched in the endoplasmic reticulum, and that it functioned by regulating Ca2+ dynamics and the unfolded protein response (UPR). Given this genetic linkage of the UPR to hearing loss, we demonstrated a direct link between the more common noise-induced hearing loss (NIHL) and the UPR. These experiments suggested a novel approach to treatment. We demonstrated that the small-molecule UPR and stress response modulator ISRIB (Integrated Stress Response Inhibitor), which activates eIF2B, prevented NIHL in a mouse model. Moreover, in an inverse genetic complementation approach, we demonstrated that mice with homozygous inactivation of both Tmtc4 and Chop had less hearing loss than knockout of Tmtc4 alone. This study implicated a novel mechanism for hearing impairment, highlighting a potential treatment approach for a broad range of human hearing-loss disorders.
Authors
Jiang Li, Omar Akil, Stephanie L. Rouse, Conor W. McLaughlin, Ian R. Matthews, Lawrence R. Lustig, Dylan K. Chan, Elliott H. Sherr
Abstract
A modifier variant can abrogate risk of a monogenic disorder. DFNM1 is a locus on chromosome 1 encoding a dominant suppressor of human DFNB26 recessive, profound deafness. Here, we report that DFNB26 is associated with a substitution (p.Gly116Glu) in the pleckstrin-homology-domain of GAB1, an essential scaffold in the MET/HGF pathway. A dominant substitution (p.Arg544Gln) of METTL13, encoding a predicted methyltransferase, is the DFNM1 suppressor of GAB1-associated deafness. In zebrafish, human METTL13 mRNA harboring the modifier allele rescues the GAB1 associated morphant phenotype. In mouse, GAB1 and METTL13 co-localize in auditory sensory neurons, and METTL13 co-immunoprecipitates with GAB1 and SPRY2, indicating at least a tripartite complex. Expression of MET-signaling genes in human lymphoblastoid cells of individuals homozygous for p.Gly116Glu GAB1 revealed dysregulation of HGF, MET, SHP2, and SPRY2, all of which have reported variants associated with deafness. However, SPRY2 was not dysregulated in normal-hearing humans homozygous for both the GAB1 DFNB26 deafness variant and the dominant METTL13 deafness suppressor, indicating a plausible mechanism of suppression. Identification of METTL13-based modification of MET-signaling provides potential therapeutic strategy for a wide range of associated hearing disorders. Furthermore, MET-signaling is essential for diverse functions in many tissues including the inner ear. Therefore, identification of the modifier of MET-signaling is likely to have broad clinical implications.
Authors
Rizwan Yousaf, Zubair M. Ahmed, Arnaud P.J. Giese, Robert J. Morell, Ayala Lagziel, Alain Dabdoub, Edward R. Wilcox, Sheikh Riazuddin, Thomas B. Friedman, Saima Riazuddin
Abstract
Exposure to aminoglycoside antibiotics can lead to the generation of toxic levels of reactive oxygen species (ROS) within mechanosensory hair cells of the inner ear that have been implicated in hearing and balance disorders. Better understanding of the origin of aminoglycoside-induced ROS could focus the development of therapies aimed at preventing this event. In this work, we used the zebrafish lateral line system to monitor the dynamic behavior of mitochondrial and cytoplasmic oxidation occurring within the same dying hair cell following exposure to aminoglycosides. The increased oxidation observed in both mitochondria and cytoplasm of dying hair cells was highly correlated with mitochondrial calcium uptake. Application of the mitochondrial uniporter inhibitor Ru360 reduced mitochondrial and cytoplasmic oxidation, suggesting that mitochondrial calcium drives ROS generation during aminoglycoside-induced hair cell death. Furthermore, targeting mitochondria with free radical scavengers conferred superior protection against aminoglycoside exposure compared with identical, untargeted scavengers. Our findings suggest that targeted therapies aimed at preventing mitochondrial oxidation have therapeutic potential to ameliorate the toxic effects of aminoglycoside exposure.
Authors
Robert Esterberg, Tor Linbo, Sarah B. Pickett, Patricia Wu, Henry C. Ou, Edwin W. Rubel, David W. Raible
Abstract
Bacterial infections represent a rapidly growing challenge to human health. Aminoglycosides are widely used broad-spectrum antibiotics, but they inflict permanent hearing loss in up to ~50% of patients by causing selective sensory hair cell loss. Here, we hypothesized that reducing aminoglycoside entry into hair cells via mechanotransducer channels would reduce ototoxicity, and therefore we synthesized 9 aminoglycosides with modifications based on biophysical properties of the hair cell mechanotransducer channel and interactions between aminoglycosides and the bacterial ribosome. Compared with the parent aminoglycoside sisomicin, all 9 derivatives displayed no or reduced ototoxicity, with the lead compound N1MS 17 times less ototoxic and with reduced penetration of hair cell mechanotransducer channels in rat cochlear cultures. Both N1MS and sisomicin suppressed growth of
Authors
Markus E. Huth, Kyu-Hee Han, Kayvon Sotoudeh, Yi-Ju Hsieh, Thomas Effertz, Andrew A. Vu, Sarah Verhoeven, Michael H. Hsieh, Robert Greenhouse, Alan G. Cheng, Anthony J. Ricci
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)