Crucial gene for inner ear development revealed
10 May 2005
A Deafness Research UK researcher, working as part of an international collaboration, has established one of the genes responsible for the development of the sensory regions in the inner ear, which include the hair cells that detect sound.
This discovery could have major implications in hearing research, especially in the use of stem cells to regenerate hair cells - and could ultimately lead to a treatment for deafness.
Deafness Research UK researcher Professor Karen Steel worked with scientists at the University of Hong Kong and Nottingham's Medical Research Council in uncovering the significance of the gene Sox2.
The study, published in this month's Nature journal, looked at two sets of mice, one group completely deaf and the other severely hearing impaired. Both had balance problems. Knowing that hair cells detect sounds and their associated supporting cells in the inner ear are paramount to hearing, the team studied these cells within the ears of the two groups of mice.
Professor Steel and the team found that the deaf mice had no hair cells or supporting cells and malformed inner ears, and the hearing impaired mice had very few hair cells and abnormally developed inner ears. They found that this was due to the lack of Sox2 activity in the ear in the deaf mice and reduced Sox2 activity in the hearing impaired mice.
The discovery of Sox2's developmental role could open up exciting research avenues, says Professor Steel.
"We have identified a gene that controls development of all the cells that detect sound and balance in the inner ear. Manipulation of this gene could allow us to regenerate key parts of the auditory system in people with hearing impairment.
"If we want to use regeneration as a therapy to treat deafness, then we have to look further than hair cells. Supporting cells will be just as important because they are needed for the hair cells to survive and function. Sox2 is now the best choice of gene we have to test whether we can trigger regeneration of all the cell types needed for normal hearing," says Professor Steel.
"We have much more work to do on the inner ear, including looking more closely at Sox2 and the role it plays. There are also many more genes involved in the process that we need to learn more about."
Professor Steel's work was partly funded by Deafness Research UK.
