Hopes of cure for deaf in cells breakthrough

A leading charity last night described the laboratory research as "really exciting" and said it had the potential to benefit millions of people.

The work holds out the prospect of regenerating the sensitive hair

cells that turn sound vibrations into nerve signals.

Humans are born with 30,000 hair cells in each ear. When these are are lost or damaged – possibly due to excessively loud noise – it can lead to permanent hearing loss or tinnitus.

Damage to hair cells may also affect balance, causing vertigo and dizziness, and regenerating them has been a key aim of deafness research.

A team led by Professor Stefan Heller, from Stanford University School of Medicine in California, succeeded in programming mouse stem cells to develop into immature hair cells.

Most importantly, tests showed the cells responded to being moved the way hair cells do, by converting mechanical signals into electrical ones.

Experts hope the cells, which could be made in large numbers from multiplying stem cells, will provide an invaluable research tool for studying hearing and deafness.

Further down the line, they may also help scientists find a way of coaxing a patient's hair cells to renew themselves.

The Yorkshire research is supported by the Royal National Institute for Deaf people (RNID).

Dr Ralph Holme, head of biomedical research at the charity, said: "The possibility that stem cells could one day be used to restore hearing is really exciting and could benefit millions.

"RNID-funded research has shown that human stem cells can also give rise to hair-like cells, an important step forward in developing a clinically relevant therapy.

"We are now supporting research to investigate whether hearing can be restored using these cells in pre-clinical models of deafness and to find ways of scaling up the production of safe, clinical-grade cells."

Last year RNID-funded scientists at Sheffield University announced the creation of early versions of human inner ear hair cells. But their cells were not as formed and functional as those of the American scientists and lacked hair-like structures.

The Sheffield scientists, led by Dr Marcello Rivolta, are now grafting the cells into the ears of rodents with hearing loss. The hope is that once transplanted they will develop into working hair cells.

The Stanford research, the first to create functional inner-ear cells, is reported in Cell.