New research with funding from UK charity Action on Hearing Loss has led to the discovery of a new biological mechanism involved in the progressive loss of hearing which could lead to new approaches to treating this common form of hearing loss.
It's known that gradual loss of sound-detecting sensory hair cells within the inner ear is associated with progressive hearing loss, but now researchers from King's College London, the Wellcome Trust Sanger Institute, and University College London have now shown that defects in a structure within the ear called the stria vascularis, can also cause progressive hearing loss.
The stria vascularis is essential for normal hearing and is involved in maintaining the endocochlear potential - a difference in charged molecules between compartments of the inner ear which act like a battery to power the transmission of sound signals from the ear to the brain.
Researchers made the discovery while investigating why mice with a specific mutation in a gene called S1pr2 have a progressive loss of hearing and found degeneration of the stria vascularis and a low endocochlear potential in these mice correlated with their loss of hearing. Significantly, the gene in humans is also associated with changes in people's ability to hear - making this discovery relevant to progressive hearing loss in the human population.
Professor Karen Steel at King's College London who led the research said: 'Our finding suggests that designing treatments to boost the function of the stria vascularis could be important in treating some forms of progressive hearing loss. What is needed now are accurate ways of diagnosing what part of the ear is affected so that in the future the most appropriate treatment can be administered.'
Ralph Holme, Head of Biomedical at Action on Hearing Loss said: 'Hearing Loss affects as many as 1 in 6 people in the UK and all too often isolates people from friends and family. By funding cutting edge research to increase our understanding of progressive hearing loss we aim to bring the development of urgently needed treatments a step closer.'
Action on Hearing Loss runs the world's largest donor-supported hearing research programme, dedicated to funding research into better treatments and cures for hearing loss and tinnitus.
Article: S1PR2 variants associated with auditory function in humans and endocochlear potential decline in mouse, Neil J. Ingham, Francesca Carlisle, Selina Pearson, Morag A. Lewis, Annalisa Buniello, Jing Chen, Rivka L. Isaacson, Johanna Pass, Jacqueline K. White, Sally J. Dawson & Karen P. Steel, Scientific Reports, doi:10.1038/srep28964, published online 7 July 2016.