Stanford lab create inner-ear hair cells in a dish
Posted May 20 2010 1:08pm
Deep inside the ear, specialized cells called hair cells detect vibrations in the air and translate them into sound. Ten years ago, Stefan Heller, PhD, professor of otolaryngology at the Stanford University School of Medicine, came up with the idea that if you could create these cells in the laboratory from stem cells, it would go a long way toward helping scientists understand the molecular basis of hearing in order to develop better treatments for deafness.
After years of lab work, researchers in Heller’s lab report in the May 14 issue of Cell that they have found a way to develop mouse cells that look and act just like the animal’s inner-ear hair cells the linchpin to our sense of hearing and balance in a petri dish.
If they can further perfect the recipe to generate hair cells in the millions, it could lead to significant scientific and clinical advances along the path to curing deafness in the future, they said.
“This gives us real hope that there might be some kind of therapy for regenerating hair cells,” said David Corey, PhD, professor of neurobiology at Harvard University who was not involved in the study. “It could take a decade or more, but it’s a possibility.”
Using both embryonic stem cells from mice as well as reprogrammed mouse fibroblasts (a type of relatively undifferentiated cell found in many parts of the body), the researchers present a step-by-step guide on how to coax these cells into the sensory cells that normally reside in the inner ear.
“We knew it was really working when we saw them in the electron microscope,” Heller said. “They really looked like they were more or less taken out of the ear.”
Humans are born with 30,000 cochlear and vestibular hair cells per ear. (By contrast, one retina harbors about 120 million photoreceptors.) When a significant number of these cells are lost or damaged, hearing loss occurs. The major reason for hearing loss and certain balance disorders is that unlike other species such as birds humans and other mammals are unable to spontaneously regenerate these hearing cells.