A newly arrived UW researcher and colleagues at two other universities published stem-cell research results this week based on the successful growth of sound-signal-sending hair genes in the ears of lab mice, a process that could eventually be used to restore hearing to deaf people.

The article in Nature describes a regeneration process — in which functional hair gene cells are introduced into the inner ears of mice embryos — that was conducted by Dr. Samuel Gubbels, an assistant professor of surgery at the UW School of Medicine and Public Health, and collaborators at the Oregon Health and Science University, where Gubbels served his residency, and Stanford University.

Those hairs are important to the hearing process because they take sounds and change them into electric signals that are sent to the brain.

A "hair growing gene," called Atoh 1, has been used in previous studies over the past decade targeting hearing loss and the attempts to grow new auditory hair cells, and was used successfully two years ago by University of Michigan researchers in a limited study on guinea pigs. That success was named in 2005 to Scientific American's top 50 list honoring trends in research, business, and policy.

According to 2006 statistics from the National Center for Health Statistics, 37 million adults in the United States had trouble hearing. The majority lose hearing with age, partly due to the loss of hair cells in the cochlea, or because of exposure to loud noises, which also hurts the hair cells. Finding a way to get those cells to grow again could restore some hearing.

The study by Gubbels and his fellow researchers is the first to show that introducing the gene Atoh 1 in utero early in development produced hair cells that work.

The hair cells also made rudimentary connections with central nervous system cells critical to hearing, and they displayed an ability to transmit signals mechanically, further evidence that they were true, functioning hair cells.

Hard to regenerate

Gubbels, is an otolaryngologist who specializes in cochlear implantation, diseases of the ear, hearing rehabilitation, facial nerve disorders and skull-base surgery.

"Most forms of hearing loss and some forms of balance disorders are characterized by a loss of hair cells in the inner ear," he said. "Aside from using hearing aids and cochlear implants, we have been plagued with an inability to restore hearing because it's very difficult for hair cells to regenerate."

Successfully using a technique of introducing the cell in utero is also unique, Gubbels said, and will allow researchers to design and measure gene therapies, which he described as "an important step in defining regenerative approaches to treat inner-ear disease in humans."

Gubbels' collaborators on the study included David Woessner, John Mitchell and John Brigande of OHSU and Anthony Ricci at Stanford.

Gubbels arrived in Madison this summer, and is working with investigators at the UW Waisman Center, conducting studies on regenerative therapies for hearing loss.

He cautioned that "it will be a long time before (the research) has clinical applicability. Our model system and our findings still leave us a long ways away. Our hope is, in an ideal world, to regenerate the hair cells people were born with."