Hair cell renewal paves way towards a cure for deafness

SCIENTISTS hope they have paved the way to a cure for deafness by creating vital parts of the ear from stem cells.

The researchers have succeeded in creating inner ear sensory cells in the lab, which could lead to treatments for deaf patients.

Campaigners yesterday described the research as "really exciting", with the potential to benefit millions of people suffering hearing loss.

The team, writing in the journal Cell, believe their work holds 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 the cells are lost or damaged – possibly due to excessively loud noise – it can lead to permanent hearing loss or tinnitus (ringing in the ears).

Damage to hair cells may also affect balance, causing symptoms of vertigo and dizziness.

Regenerating the sensory hair cells of the inner ear has been a vital aim of deafness research.

Stem cells are the building blocks of the body, with the potential to turn into different parts of the anatomy.

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

Viewed under a microscope, the cells created by the US scientists were seen to have bundled structures reminiscent of the hair-like tufts of "stereocilia" that give the cells their name.

"They really looked like they were more or less taken out of the ear," Prof Heller said.

Most importantly, tests showed that 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 the molecular basis of 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 research is already being taken forward by scientists 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."