Differentiation of adult mouse olfactory precursor cells into hair cells in vitro.

Many forms of deafness result from degeneration of the sensory cells for hearing, the hair cells in the cochlea. Stem cells offer a potential cell-based therapy for the treatment of deafness. Here, we investigate whether adult olfactory precursor cells can differentiate into hair cells in culture. Precursor cells were isolated from mouse olfactory neuroepithelium, were sphere-forming, showed proliferative capacity, and contained cells expressing neuronal and non-neuronal proteins. To induce differentiation, precursor cells were cocultured with cochlear cells and/or cochlear supernatant. Differentiated precursor cells were immunopositive for specific hair cell markers, including myosin VIIa, FM1-43, calretinin, phalloidin, and espin, and resembled hair cells anatomically and immunocytochemically in culture. The results demonstrate for the first time that adult olfactory precursor cells can differentiate into hair cell-like cells, thus providing a potential autotransplantation therapy for hearing loss.