Hearing cells regenerated in mice

Damage to the hair cells inside the cochlea is known to be irreversible. However, a recent study in mice brings real ray of hope in this field...

According to the Inserm, 6% of 15-24 year olds and 65% of those over 65 are affected by deafness. Even if this disorder can be present from birth, with in majority a genetic origin, it can also be acquired during life. Various causes are possible: acoustic trauma, diseases, accidents, or ototoxicity caused by certain drugs for example. Aging also leads to a natural hearing loss.

A study published in Frontiers in Cellular Neuroscience published interesting results in mice earlier this year. They were inspired by a phenomenon existing in birds, which have the ability to regularly regenerate their hair cells. In short, the researchers made mouse hair cells express the EGF growth factor receptor in vivo, ERBB2, which led to the differentiation of cells surrounding the hair cells, an essential step for regeneration. Hair cells expressing ERBB2 actually produced proteins activating the CD44 receptor pathway in these peripheral cells, triggering their differentiation, which could ultimately permit hair cell regeneration.

These results are promising but several steps between CD44 activation and possible hair cell regeneration are still very much unknown. Moreover, the use of ERBB2 in humans seems compromised since it is a gene that can cause the proliferation of cancerous cells, but the dozens of teams working on this subject are not losing hope in finding a solution to restore hearing!