Could hair cell regeneration be a treatment for deafness?

Researchers have proposed the use embryonic stem cells for in vitro inner ear studies to potentially be a treatment for deafness. Deafness due to disease, ageing or birth defects is caused by the loss of hair cells in the inner ear, the hairs which are responsible for the detection of equilibrium and sound. Currently, deafness is a progressive and irreversible condition in humans, with the typical treatment to be the use of hearing aids.

The scientists proposed to use embryonic stem cells (ESCs) as a platform for in-vitro inner ear studies. Embryonic Stem cells establish an alternative and powerful approach to generate unlimited numbers of hair cells in a simple culture dish without the use of animals.

Through genetic manipulation of embryonic stem cells to activate expression of these transcriptional regulators, a direct and robust conversion of stem cells into a hair cell phenotype was successfully achieved. Using the in vitro culture, researchers were able to provide vital insight into the dynamics of hair cell regeneration. Atoh1 had been the main protein undergoing intense research, as it is a key player in identifying the regeneration of lost hair cells in patients with deafness. However, Atoh1 demonstrated limited regenerative capacity, indicating that other factors are incriminate in the process. During the GRN Hair Cell study, it was identified that Gfi1 as a switch to hair cell commitment and a contributor to Atoh1 transcriptional activity. Moreover, analysis of gene expression and protein-DNA binding activity unveiled important information on the function of these regulatory factors.

The clinical significance?

The molecular structure in which Gfi1 is able to change Atoh1 and Pou4f3 transcriptional activity is most definitely of great scientific importance. Costa highlights the fact that from a clinical perspective “it is also important to test this particular combination of transcription factors in animals with damaged inner ears to see if we can reverse the damage. ″

Although there may be no instant clinical application of the GRN Hair Cell study, but the gained knowledge brings us one step closer to apprehend the process of inner ear development and utilizing it in the therapy of deafness. Identifying the key aspects in hair cell regeneration could potentially lead scientists to establish therapeutic approaches and find a treatment for deafness.