Migration of R28 Retinal Precursor Cells into Cochlear and Vestibular Organs

Damaged hair cells and neurons in the inner ear generally can not be replaced in mammals. The loss of these cells causes permanent functional disorders in both the cochlear and vestibular systems. Transplantation of retinal precursor cells, R28 cells, into inner ear tissue may help replace missing cells. The aim of the current project was to induce R28 cell transdifferentiation into cochlear and vestibular cell types under culture conditions. The first part was related to R28 cell labeling with DiI fluorescence that would help identify and track R28 cells. The second part involved co-culturing R28 cells in cochlear and vestibular organotropic cultures or isolated spiral ganglion neurons. The results suggest that R28 cells have the potential to differentiate into supporting cell types and spiral ganglion neurons in serum free medium, probably under the influence of diffusible signals from inner ear tissues. This information is useful for future efforts in inducing stem cell differentiation in the inner ear to replace lost sensory and neural cells.