The mechanisms of age-related hearing loss

A Deafness Research UK study at Keele University is looking at the role of particular types of cells called 'fibrocytes' in age-related hearing loss.

[Project Grant, 2007-2009]

Fibrocytes are cells that line the wall of the inner ear, or cochlea. Their main role seems to be to maintain the healthy composition of fluids in the cochlea, but these cells degenerate as we get older and there are strong indications that as they die, the environment changes and becomes less suitable for the support of hair cells.

A research team led by Dr Dave Furness at Keele University are carrying out a three-year study to investigate which fibrocytes are involved in controlling the environment of the hair cells and which degenerate first.

Having the correct balance of substances in fluids in the cochlea is vital for normal hearing and for the long-term survival of the hair cells that detect sound. Fibrocyte loss has already been shown to precede hair-cell death in one form of genetic deafness caused by DFN3 mutations and there is evidence to suggest that it could also be a major factor in age-related hearing loss (presbyacusis) leading to hair cell loss.

The team will confirm the role that fibrocytes play in keeping hair cells healthy and they will then begin to work on techniques by which fibrocytes could be replaced or regenerated. Because they are derived from cells that can divide throughout life, it may be possible to replace fibrocytes by transplantation, thereby arresting the degenerative process and presbyacusis.

The researchers will use a mouse model of presbyacusis to explore how fibrocytes control the fluids, whether loss of the fibrocytes causes presbyacusis and for the development of replacement cell strategies to prevent presbyacusis.

Since more than half of the population will at some time suffer age-related hearing loss, the potential benefits of a strategy for early intervention are enormous.