NIDCD-funded Hair Cell Regeneration Studies Make Scientific American's Top 50 List for 2005
NIDCD-funded research on the use of gene therapy to regenerate auditory hair cells in guinea pigs and mice was included in Scientific American's top 50 list honoring trends in research, business, and policy for 2005. The honored researchers were Yehoash Raphael, Ph.D., University of Michigan Medical School, Ann Arbor, and Zheng-Yi Chen, Ph.D., Massachusetts General Hospital, Boston.
"The ability to grow new auditory hair cells to replace damaged ones is a research priority for NIDCD and a prospect that holds tremendous promise in the coming decades," says NIDCD director James F. Battey, Jr., M.D., Ph.D. "Our hope is that this and other innovative research in gene therapy may one day be used to safely and effectively treat sensorineural hearing loss in people."
Hair cells, small sensory cells in the inner ear, are chiefly responsible for converting sound vibrations into electrical signals, which are interpreted—or "heard"—by the brain. When hair cells become damaged—either by disease, injury, or aging—a person experiences hearing loss, sometimes profound. While fish, amphibians, and birds are able to grow new hair cells to replace damaged ones, mammals cannot regenerate hair cells on their own.
The studies involve the coaxing of new auditory hair cell growth by either inserting a gene that promotes hair cell growth or by deleting a gene that prevents it. Dr. Raphael and his team used a modified virus to transport the Atoh 1 gene, a key gene for the development of hair cells, into non-sensory epithelial cells in the inner ears of deafened guinea pigs. After eight weeks, the scientists discovered new hair cell growth in the inner ears of the guinea pigs as well as improved hearing function. (Read more about his research.) Dr. Chen and colleagues identified a key gene, called Rb1, which shuts down further growth of hair cells during the early stages of development. Mice bred to be missing the gene were able to grow more functioning hair cells than mice possessing the gene. In addition, mature hair cells growing in culture dishes were able to regenerate when the gene was deleted. (Read more about his research.)