{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T11:36:16Z","timestamp":1790076976918,"version":"4.0.1"},"reference-count":42,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,7,14]],"date-time":"2021-07-14T00:00:00Z","timestamp":1626220800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["406266759"],"award-info":[{"award-number":["406266759"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["416097726"],"award-info":[{"award-number":["416097726"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["416116807"],"award-info":[{"award-number":["416116807"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Neurosci."],"abstract":"<jats:p>Deficiency of otoferlin causes profound prelingual deafness in humans and animal models. Here, we closely analyzed developmental deficits and degenerative mechanisms in <jats:italic>Otof<\/jats:italic> knock-out (<jats:italic>Otof<\/jats:italic><jats:sup>\u2013\/\u2013<\/jats:sup>) mice over the course of 48 weeks. We found otoferlin to be required for proper synapse development in the immature rodent cochlea: In absence of otoferlin, synaptic pruning was delayed, and postsynaptic boutons appeared enlarged at 2 weeks of age. At postnatal day 14 (P14), we found on average \u223c15 synapses per inner hair cell (IHC) in <jats:italic>Otof<\/jats:italic><jats:sup>\u2013\/\u2013<\/jats:sup> cochleae as well as in wild-type controls. Further on, the number of synapses in <jats:italic>Otof<\/jats:italic><jats:sup>\u2013\/\u2013<\/jats:sup> IHCs was reduced to \u223c7 at 8 weeks of age and to \u223c6 at 48 weeks of age. In the same period, the number of spiral ganglion neurons (SGNs) declined in <jats:italic>Otof<\/jats:italic><jats:sup>\u2013\/\u2013<\/jats:sup> animals. Importantly, we found an age-progressive loss of IHCs to an overall number of 75% of wildtype IHCs. The IHC loss more prominently but not exclusively affected the basal aspects of the cochlea. For outer hair cells (OHCs), we observed slightly accelerated age-dependent degeneration from base to apex. This was associated with a progressive decay in DPOAE amplitudes for high frequency stimuli, which could first be observed at the age of 24 weeks in <jats:italic>Otof<\/jats:italic><jats:sup>\u2013\/\u2013<\/jats:sup> mice. Our data will help to plan and predict the outcome of a gene therapy applied at various ages of DFNB9 patients.<\/jats:p>","DOI":"10.3389\/fncel.2021.677543","type":"journal-article","created":{"date-parts":[[2021,7,14]],"date-time":"2021-07-14T09:04:22Z","timestamp":1626253462000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":40,"title":["Otoferlin Is Required for Proper Synapse Maturation and for Maintenance of Inner and Outer Hair Cells in Mouse Models for DFNB9"],"prefix":"10.3389","volume":"15","author":[{"given":"Ursula","family":"Stalmann","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Albert Justin","family":"Franke","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hanan","family":"Al-Moyed","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicola","family":"Strenzke","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ellen","family":"Reisinger","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,7,14]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"4496","DOI":"10.1073\/pnas.1817537116","article-title":"Dual AAV-mediated gene therapy restores hearing in a DFNB9 mouse model.","volume":"116","author":"Akil","year":"2019","journal-title":"Proc. Natl. Acad. Sci. U.S.A."},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.15252\/emmm.201809396","article-title":"A dual-AAV approach restores fast exocytosis and partially rescues auditory function in deaf otoferlin knock-out mice.","volume":"11","author":"Al-Moyed","year":"2019","journal-title":"EMBO Mol. Med."},{"key":"B3","doi-asserted-by":"publisher","first-page":"13281","DOI":"10.1523\/JNEUROSCI.2528-10.2010","article-title":"Control of exocytosis by synaptotagmins and otoferlin in auditory hair cells.","volume":"30","author":"Beurg","year":"2010","journal-title":"J. Neurosci."},{"key":"B4","doi-asserted-by":"publisher","first-page":"251","DOI":"10.1038\/s41434-018-0012-0","article-title":"AAV-mediated NT-3 overexpression protects cochleae against noise-induced synaptopathy.","volume":"25","author":"Chen","year":"2018","journal-title":"Gene Ther."},{"key":"B5","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1038\/mt.2009.258","article-title":"Characterization of genome integrity for oversized recombinant AAV vector.","volume":"18","author":"Dong","year":"2010","journal-title":"Mol. Ther."},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-019-51724-6","article-title":"Protection from noise-induced cochlear synaptopathy by virally mediated overexpression of NT3.","volume":"9","author":"Hashimoto","year":"2019","journal-title":"Sci. Rep."},{"key":"B7","doi-asserted-by":"crossref","DOI":"10.1186\/1749-8104-7-38","article-title":"Synaptic profiles during neurite extension, refinement and retraction in the developing cochlea.","volume":"7","author":"Huang","year":"2012","journal-title":"Neural Dev."},{"key":"B8","doi-asserted-by":"publisher","first-page":"4456","DOI":"10.1523\/JNEUROSCI.3491-12.2013","article-title":"Disruption of the presynaptic cytomatrix protein bassoon degrades ribbon anchorage, multiquantal release, and sound encoding at the hair cell afferent synapse.","volume":"33","author":"Jing","year":"2013","journal-title":"J. Neurosci."},{"key":"B9","doi-asserted-by":"publisher","first-page":"80","DOI":"10.1016\/j.heares.2011.11.007","article-title":"Genetic background effects on age-related hearing loss associated with Cdh23 variants in mice.","volume":"283","author":"Kane","year":"2012","journal-title":"Hear. Res."},{"key":"B10","doi-asserted-by":"publisher","first-page":"4434","DOI":"10.1523\/JNEUROSCI.2228-18.2019","article-title":"Vesicular glutamatergic transmission in noise-induced loss and repair of cochlear ribbon synapses.","volume":"39","author":"Kim","year":"2019","journal-title":"J. Neurosci."},{"key":"B11","doi-asserted-by":"publisher","first-page":"184","DOI":"10.1097\/AUD.0000000000000586","article-title":"Deterioration in distortion product otoacoustic emissions in auditory neuropathy patients with distinct clinical and genetic backgrounds.","volume":"40","author":"Kitao","year":"2019","journal-title":"Ear Hear."},{"key":"B12","doi-asserted-by":"publisher","first-page":"281","DOI":"10.1038\/28401","article-title":"Expression of a potassium current in inner hair cells during development of hearing in mice.","volume":"394","author":"Kros","year":"1998","journal-title":"Nature"},{"key":"B13","doi-asserted-by":"crossref","DOI":"10.1523\/JNEUROSCI.2845-09.2009","article-title":"Adding insult to injury: cochlear nerve degeneration after \u201ctemporary\u201d noise-induced hearing loss.","volume":"29","author":"Kujawa","year":"2009","journal-title":"J. Neurosci."},{"key":"B14","doi-asserted-by":"publisher","first-page":"191","DOI":"10.1016\/j.heares.2015.02.009","article-title":"Synaptopathy in the noise-exposed and aging cochlea: primary neural degeneration in acquired sensorineural hearing loss.","volume":"330","author":"Kujawa","year":"2015","journal-title":"Hear. Res."},{"key":"B15","doi-asserted-by":"publisher","first-page":"75","DOI":"10.1038\/mt.2009.256","article-title":"Evidence for the failure of adeno-associated virus serotype 5 to package a viral genome = 8.2 kb.","volume":"18","author":"Lai","year":"2010","journal-title":"Mol. Ther."},{"key":"B16","doi-asserted-by":"publisher","first-page":"383","DOI":"10.1113\/jphysiol.2002.034801","article-title":"Developmental changes in the expression of potassium currents of embryonic, neonatal and mature mouse inner hair cells.","volume":"548","author":"Marcotti","year":"","journal-title":"J. Physiol."},{"key":"B17","doi-asserted-by":"publisher","first-page":"743","DOI":"10.1113\/jphysiol.2003.043612","article-title":"Sodium and calcium currents shape action potentials in immature mouse inner hair cells.","volume":"552","author":"Marcotti","year":"","journal-title":"J. Physiol."},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1186\/s13073-016-0273-4","article-title":"Correction of the auditory phenotype in C57BL\/6N mice via CRISPR\/Cas9-mediated homology directed repair.","volume":"8","author":"Miann\u00e9","year":"2016","journal-title":"Genome Med."},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.7554\/eLife.31013","article-title":"Otoferlin acts as a Ca2+ sensor for vesicle fusion and vesicle pool replenishment at auditory hair cell ribbon synapses.","volume":"6","author":"Michalski","year":"2017","journal-title":"eLife"},{"key":"B20","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1016\/j.heares.2004.08.011","article-title":"A physiological place-frequency map of the cochlea in the CBA\/J mouse.","volume":"202","author":"M\u00fcller","year":"2005","journal-title":"Hear. Res."},{"key":"B21","doi-asserted-by":"publisher","first-page":"1849","DOI":"10.1016\/j.neuroscience.2006.05.057","article-title":"Synaptic organization in cochlear inner hair cells deficient for the CaV1.3 (alpha1D) subunit of L-type Ca2+ channels.","volume":"141","author":"Nemzou","year":"2006","journal-title":"Neuroscience"},{"key":"B22","doi-asserted-by":"publisher","first-page":"869","DOI":"10.1038\/nn.2578","article-title":"Hearing requires otoferlin-dependent efficient replenishment of synaptic vesicles in hair cells.","volume":"13","author":"Pangrsic","year":"2010","journal-title":"Nat. Neurosci."},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.3389\/fnmol.2020.600051","article-title":"Overloaded adeno-associated virus as a novel gene therapeutic tool for otoferlin-related deafness.","volume":"13","author":"Rankovic","year":"2020","journal-title":"Front. Mol. Neurosci."},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1016\/j.heares.2019.107857","article-title":"Dual-AAV delivery of large gene sequences to the inner ear.","volume":"394","author":"Reisinger","year":"2020","journal-title":"Hear. Res."},{"key":"B25","doi-asserted-by":"publisher","first-page":"4886","DOI":"10.1523\/JNEUROSCI.5122-10.2011","article-title":"Probing the functional equivalence of otoferlin and synaptotagmin 1 in exocytosis.","volume":"31","author":"Reisinger","year":"2011","journal-title":"J. Neurosci."},{"key":"B26","doi-asserted-by":"publisher","first-page":"451","DOI":"10.1002\/humu.10274","article-title":"Auditory neuropathy in patients carrying mutations in the otoferlin gene (OTOF).","volume":"22","author":"Rodr\u00edguez-Ballesteros","year":"2003","journal-title":"Hum. Mutat."},{"key":"B27","doi-asserted-by":"publisher","first-page":"823","DOI":"10.1002\/humu.20708","article-title":"A multicenter study on the prevalence and spectrum of mutations in the otoferlin gene (OTOF) in subjects with nonsyndromic hearing impairment and auditory neuropathy.","volume":"29","author":"Rodr\u00edguez-Ballesteros","year":"2008","journal-title":"Hum. Mutat."},{"key":"B28","doi-asserted-by":"publisher","first-page":"689","DOI":"10.1016\/j.ijporl.2005.09.006","article-title":"Results of cochlear implantation in two children with mutations in the OTOF gene.","volume":"70","author":"Rouillon","year":"2006","journal-title":"Int. J. Pediatr. Otorhinolaryngol."},{"key":"B29","doi-asserted-by":"publisher","first-page":"277","DOI":"10.1016\/j.cell.2006.08.040","article-title":"Otoferlin, defective in a human deafness form, is essential for exocytosis at the auditory ribbon synapse.","volume":"127","author":"Roux","year":"2006","journal-title":"Cell"},{"key":"B30","doi-asserted-by":"publisher","first-page":"200","DOI":"10.1016\/j.heares.2015.07.007","article-title":"Audibility, speech perception and processing of temporal cues in ribbon synaptic disorders due to OTOF mutations.","volume":"330","author":"Santarelli","year":"2015","journal-title":"Hear. Res."},{"key":"B31","doi-asserted-by":"publisher","first-page":"3372","DOI":"10.1111\/j.1460-9568.2006.05225.x","article-title":"Differential expression of otoferlin in brain, vestibular system, immature and mature cochlea of the rat.","volume":"24","author":"Schug","year":"2006","journal-title":"Eur. J. Neurosci."},{"key":"B32","doi-asserted-by":"publisher","first-page":"263","DOI":"10.1016\/j.neuron.2007.11.032","article-title":"Sensorineural deafness and seizures in mice lacking vesicular glutamate transporter 3.","volume":"57","author":"Seal","year":"2008","journal-title":"Neuron"},{"key":"B33","doi-asserted-by":"publisher","first-page":"13686","DOI":"10.1523\/JNEUROSCI.1783-13.2013","article-title":"Age-related cochlear synaptopathy: an early-onset contributor to auditory functional decline.","volume":"33","author":"Sergeyenko","year":"2013","journal-title":"J. Neurosci."},{"key":"B34","doi-asserted-by":"publisher","first-page":"1229","DOI":"10.1016\/j.cell.2018.07.007","article-title":"Sensory neuron diversity in the inner ear is shaped by activity.","volume":"174","author":"Shrestha","year":"2018","journal-title":"Cell"},{"key":"B35","doi-asserted-by":"crossref","first-page":"741","DOI":"10.1093\/brain\/119.3.741","article-title":"Auditory neuropathy.","volume":"119","author":"Starr","year":"1996","journal-title":"Brain"},{"key":"B36","doi-asserted-by":"publisher","DOI":"10.15252\/embj.201694564","article-title":"Hair cell synaptic dysfunction, auditory fatigue and thermal sensitivity in otoferlin Ile515Thr mutants.","volume":"35","author":"Strenzke","year":"2016","journal-title":"EMBO J."},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.3389\/fnmol.2018.00492","article-title":"Disruption of otoferlin alters the mode of exocytosis at the mouse inner hair cell ribbon synapse.","volume":"11","author":"Takago","year":"2019","journal-title":"Front. Mol. Neurosci."},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.3390\/genes11121411","article-title":"The many faces of DFNB9: relating OTOF variants to hearing impairment.","volume":"11","author":"Vona","year":"2020","journal-title":"Genes"},{"key":"B39","doi-asserted-by":"publisher","first-page":"80","DOI":"10.1038\/mt.2009.255","article-title":"Effect of genome size on AAV vector packaging.","volume":"18","author":"Wu","year":"2010","journal-title":"Mol. Ther."},{"key":"B40","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1086\/303049","article-title":"OTOF encodes multiple long and short isoforms: genetic evidence that the long ones underlie recessive deafness DFNB9.","volume":"67","author":"Yasunaga","year":"2000","journal-title":"Am. J. Hum. Genet."},{"key":"B41","doi-asserted-by":"publisher","first-page":"363","DOI":"10.1038\/7693","article-title":"A mutation in OTOF, encoding otoferlin, a FER-1-like protein, causes DFNB9, a nonsyndromic form of deafness.","volume":"21","author":"Yasunaga","year":"1999","journal-title":"Nat. Genet."},{"key":"B42","doi-asserted-by":"publisher","DOI":"10.3389\/fnins.2020.00447","article-title":"Cochlear Implantation Outcomes in Patients With OTOF Mutations.","volume":"14","author":"Zheng","year":"2020","journal-title":"Front. Neurosci."}],"container-title":["Frontiers in Cellular Neuroscience"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fncel.2021.677543\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,7,14]],"date-time":"2021-07-14T09:04:29Z","timestamp":1626253469000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fncel.2021.677543\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,7,14]]},"references-count":42,"alternative-id":["10.3389\/fncel.2021.677543"],"URL":"https:\/\/doi.org\/10.3389\/fncel.2021.677543","relation":{},"ISSN":["1662-5102"],"issn-type":[{"value":"1662-5102","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,7,14]]},"article-number":"677543"}}