U.K. scientists are turning to human embryonic stem cells as a possible cure for some forms of deafness, and they achieved partial success testing the idea with deaf gerbils.
Scientists at the University of Sheffield in Sheffield, England, say their concept would help patients with auditory neuropathy, a form of deafness where nerves that carry acoustic signals to the brain are either destroyed or damaged. Details of their research can be found in the journal Nature. News organizations including The Guardian and The Associated Press offer interesting highlights of the major findings.
So why gerbils, you might ask? The Guardian explains that their hearing range is similar to humans. But a gerbil that regained partial hearing doesn't mean the same thing will happen with people, so lots of additional research is required before the preclinical promise can be matched in human trials. Stem cell treatments also remain somewhat unpredictable and could cause secondary health issues if they don't work right. That said, a stem cell treatment for auditory neuropathy would be a provocative alternative to cochlear implants. And it would join other preclinical treatments under development with other targets in mind. The Emory University School of Medicine, for example, is testing gene therapy on mice to restore hearing by growing sensory hair cells in the inner ear. Of course, neither preclinical treatment option would work for all kinds of hearing loss.
The Sheffield scientists used the stem cells, plus chemical growth factors, to create auditory neurons and sensory hair cells found in the cochlea in the inner ear, according to the articles, both of which help to translate sounds into electrical signals. They transplanted only the auditory neurons into the deaf ears of 18 gerbils, all made that way after researchers killed the nerve cells that enabled hearing. As The Guardian notes, each of the animals regained nearly half of their potential hearing on average, though some experienced only a small improvement. While the Sheffield researchers haven't tested the sensory hair cells in animals, they likely will at some point, as that kind of therapy could reach more of the deaf population, according to the stories (something the Emory team thought of with their research).
- read The Guardian's coverage
- here's the AP story (via USA Today)
- check out the Nature abstract