Nasal stem cells can aid hearing

Melbourne: In what could help restore hearing loss in humans, an Indian-origin scientist-led team has shown for the first time that injecting stem cells from nose into ears of mice with deafness improved their hearing.

Sonali Pandit and colleagues at Garvan Institute of Medical Research in Australia have claimed that the research has the potential to reverse or restore hearing during early onset sensorineural hearing loss in people.

Sensorineural hearing loss occurs when hearing cells in the cochlea lose their function. Frequently inherited, and usually starting during infancy, the condition could slow a child`s development and lead to speech and language problems.

The team found that stem cells appear to release "factors", or chemical substances, that help preserve the function of cochlear hearing cells, without the stem cells becoming part of the tissue of the inner ear.

"We are exploring the potential of stem cells to prevent or restore hearing loss in people. The mice we are using have a very similar form of childhood deafness to their human counterparts -except, of course, that mouse years are shorter. So a mouse will tend to lose their hearing within 3 months, where a person might take 8 years.

"We are encouraged by our initial findings, because all the mice injected with stem cells showed improved hearing in comparison with those given a sham injection. Roughly half of the mice did very well indeed, although it is important to note that hearing wasn`t completely restored to normal hearing levels,"team member Sharon Oleskevich said.

Adult human nasal stem cells were used in the study, as they are plentiful, easy to obtain and unspecialised (so have the ability to self-renew for long periods, as well as differentiate into cells with a variety of functions).

Though it has taken five years to reach the current stage of research, the scientists anticipate that it will take a further decade at least for the findings to benefit people.

The findings have been published in the latest edition of the `Stem Cells` journal.