This is a PhD studentship being carried out in the laboratory of Professor Andrea Streit at King’s College London. The project started in October 2015 and will finish in September 2018.
Normal hearing depends on highly specialised cells in the ear, the sensory hair cells. Many kinds of hearing loss, including deafness from birth and age-related hearing loss, are caused by the loss of hair cells.
In mammals, including humans, this loss is irreversible. In some animals, like the mouse, hair cells can regenerate – from other cells in the inner ear, called supporting cells. But in mice, the ability to do this declines rapidly within two weeks of birth. We don't know why. Until we do, it will be difficult to develop new treatments to stimulate hair cell regeneration.
Recently, it has become clear that human disease and age-related changes can be associated with changes that alter how genes function and are activated, without changes to the DNA sequence of the gene itself. These changes are called 'epigenetic' modifications. They are reversible so we may be able to treat them with drugs in the future. Our PhD student will investigate whether epigenetic changes within supporting cells stop them being able to regenerate.
Our student is investigating why supporting cells become locked into a 'non-regenerative' state during ageing, exploring the molecular processes responsible, and then comparing this to cells that are able to regenerate. Specifically, they are working to determine which genes are turned on in supporting cells at different stages of ageing, and at different times after hair cell damage. Then they will investigate the epigenetic modifications that affect those genes’ activity.
"This study will help explain why hair cells don’t regenerate in people, unlike in other species. It could lead to ways to trigger regeneration to restore hearing."
For the first time, we'll have an in-depth view of the molecular events that accompany ageing in supporting cells in the inner ear. Our student will identify new critical genes involved in this process and, importantly, the project will highlight reversible modifications which could lead to the development of new treatments for hearing loss.