image: Organ of Corti whole-mount image, with sensory hair cells labelled with Myo7a antibody (red) showing 3 rows of outer hair cells (top) and one row of inner hair cells (bottom). Nuclei labelled with DAPI (blue). view more
Credit: Elisa Martelletti
A large-scale screen of mouse mutants has revealed multiple new genes involved in hearing loss, according to a study publishing April 11 in the open-access journal PLOS Biology by Karen Steel of King's College London and the Wellcome Sanger Institute, and colleagues. The new genes identified reveal metabolic pathways and regulatory processes involved in hearing and provide a rich source of therapeutic targets for the restoration of hearing.
Progressive hearing loss with age is extremely common in the population, leading to difficulties in understanding speech, increased social isolation and associated depression. It has significant heritability, but so far very little is known about the molecular pathways leading to adult-onset hearing loss, hampering the development of treatments. Steel and colleagues took a genetic approach to identifying new molecules involved in hearing loss by screening a large cohort of newly generated mouse mutants using a sensitive electrophysiological test, the auditory brainstem response.
The large-scale screen of 1,211 new targeted mouse mutants resulted in the identification of 38 genes underlying hearing loss that had not previously been suspected to be involved in hearing. Some of these genes reveal molecular pathways that may be useful targets for drug development. Eleven were found to be significantly associated with auditory function in the human population, and one gene, SPNS2, was associated with childhood deafness, emphasizing the value of the mouse for identifying genes and mechanisms underlying complex processes such as hearing.
Further analysis of the genes identified and the varied pathological mechanisms within the ear resulting from the mutations suggests that hearing loss is an extremely heterogeneous disorder and may involve as many as 1,000 genes. According to the authors, the findings suggest that therapies may need to be directed at common molecular pathways involved in deafness rather than individual genes or mutations.
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In your coverage please use this URL to provide access to the freely available article in PLOS Biology: http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000194
Image Caption: Organ of Corti whole-mount image, with sensory hair cells labelled with Myo7a antibody (red) showing 3 rows of outer hair cells (top) and one row of inner hair cells (bottom). Nuclei labelled with DAPI (blue).
Image Credit: Elisa Martelletti
Citation: Ingham NJ, Pearson SA, Vancollie VE, Rook V, Lewis MA, Chen J, et al. (2019) Mouse screen reveals multiple new genes underlying mouse and human hearing loss. PLoS Biol 17(4): e3000194. https://doi.org/10.1371/journal.pbio.3000194
Funding: This work was supported by The Wellcome Trust (KPS, 098051; 100699; 089622), the Medical Research Council (KPS, MC_qA137918; G0300212), European Commission (KPS, EUMODIC contract LSHG-CT-2006-037188), Action on Hearing Loss (KPS), the Haigh Fellowship in age related deafness (SJD), and Deafness Research UK (SJD). This work made use of data and samples generated by the 1958 Birth Cohort (http://www2.le.ac.uk/projects/birthcohort, http://www.bristol.ac.uk/alspac/, http://www.cls.ioe.ac.uk/ncds, http://www.esds.ac.uk/findingData/ncds.asp) under grant G0000934 from the Medical Research Council and grant 068545/Z/02 from the Wellcome Trust. Genotyping was undertaken as part of the Wellcome Trust Case-Control Consortium (WTCCC) under Wellcome Trust award 076113, and a full list of the investigators who contributed to the generation of the data is available at http://www.wtccc.org.uk. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: ZP is employed by Ambry Genetics, and exome sequencing is among the commercially available tests. The other authors have declared that no competing interests exist.
Journal
PLoS Biology