Gene therapy against hearing loss
Hearing loss was suggested to be treated with gene therapy
The hair cells of the cochlea (inner ear) begin to oscillate under the influence of sound waves. These vibrations, in turn, irritate the nerve endings, the impulses from which enter the auditory region of the cerebral cortex, where the recognition and analysis of sounds takes place.
The Atoh1 gene controls the formation of the epithelium to which the hair cells belong.
To observe the effect of this gene, cell biologists have created a special line of mice in which Atoh1 is activated in the epithelial cells of the anterior part of the ear labyrinth in the presence of the antibiotic doxycycline. This allows you to control the process and identify new hair cells.
In the picture from the press release of Emory University School of Medicine (Gene Therapy for Hearing Loss: Potential and Limitations), mature hair cells are marked in red, green - growing; arrows indicate areas of the ear labyrinth in which hair cells normally do not grow – VM.
In previous experiments, the same gene was introduced into the cells of the cochlea of rodents on a viral vector, but one of the disadvantages of this method is the need for constant monitoring of the concentration of the therapeutic agent.
The additional hair cells obtained by the authors under the influence of the activated Atoh1 gene generate the same electrical signal and contact other neurons in the same way as normal hair cells. However, the signal produced by them is weaker than the signal from the adult hair cells of the inner ear.
"We have shown the fundamental possibility of regeneration of hair cells," says the head of the study Ping Chen (Ping Chen).
At the same time, she draws attention to the limitations of the proposed approach identified in experiments on mice. In addition to the weaker electrical signal produced by the new hair cells, the induction of the Atoh1 gene by doxycycline in rodents older than two weeks of age was insignificant. This, according to Chen, suggests that similar therapy for hearing loss in adults alone will not be effective.
Nevertheless, the results published by Emory scientists in the Journal of Neuroscience indicate the potential of a gene-therapeutic approach to the treatment of hearing loss caused by impaired functions of hair cells, sensorineural hearing loss.
Portal "Eternal youth" http://vechnayamolodost.ru14.05.2012