Hearing impairment has a profound effect on the American population, with almost thirty million people exhibiting some level of deafness or hearing loss. This disability impairs more people in terms of both numbers and economic impact than epilepsy, multiple sclerosis, spinal injury, stroke, Huntington's and Parkinson's diseases combined. The goal of our research is to investigate the therapeutic potential of stem cells transplanted into the auditory system. To this end, we will describe the experiments we have undertaken to assess the ability of stem cells to integrate into the cochlear sensory epithelium and replace damaged cochlear cells. Our first series of experiments was designed to exploit the developmental potential of stem cells by defining the in vitro conditions in which neural stem cells transdifferentiate into cochlear cell types. In the second series of experiments we have examined stem cell integration into organotypic cultures of the organ of Corti. The third series of experiments utilized the regenerative capacities of stem cells by transplanting them into the otic capsule of a noise-damaged mouse model. Our hypothesis is that the transplanted stem cells will integrate into the damaged sensory epithelium, respond to local environmental cues and differentiate into cochlear cell types.
[This work has been supported by a grant from the National Organization for Hearing Research Foundation.]