We are funding Dr Lisa Nolan, one of our Pauline Ashley New Investigators, at the UCL Ear Institute. This aspect of Dr Nolan's research, which focuses on the role of estrogen in hearing, ends in July 2017.
Gradual onset, age-related hearing loss affects most of us as we grow older. Although both environmental and genetic factors play a role, it is more common and more severe in men than women.
In recent years, many scientists have focused on the fact that women do not develop age-related hearing loss until they are post-menopausal (usually in their 50s) – when their levels of the hormone oestrogen decline. There is now evidence that oestrogen is not just the female sex hormone, but has other roles, including protecting against ageing and, possibly, hearing loss. Editor's note: although the common spelling in the UK is 'oestrogen' we are using 'estrogen' as it is the accepted spelling within the research community.
Estrogen affects us by binding to special molecules on the surfaces of cells, known as classical estrogen receptors. This allows it to control activity in the cells to keep them functioning correctly. In the inner ear, a lack of these receptors makes noise more damaging to the cochlea – and can lead to profound deafness.
Recent research by Dr Nolan has shown another molecule, called estrogen-related receptor gamma (ESRRG), is very similar to the classical estrogen receptors, and may be important in protecting women from age-related hearing loss.
Dr Nolan plans to investigate how the ESRRG molecule might act in the inner ear to maintain hearing. She will investigate if levels of the molecule in the cochlea differ between females and males, and also if they are affected differently by environmental stress, such as noise exposure.
By revealing the role ESRRG plays in protecting the cochlea, Dr Nolan and her colleagues will help to reveal how hearing loss progresses and will help us to understand why women are better protected against hearing loss than men. This knowledge is essential in our drive to develop treatments to treat and prevent age-related hearing loss.