Pluripotent stem cells from the adult mouse utricle

Researchers discovered that cochlear epithelia in mice especially the vestibular one, contains stem cells that have the capacity to differentiate in sensorial auditory hair cell progenitors specific to the organ. They are reduced in number as the animal progresses in age. This process leads to a loss in the regenerative and proliferative potential of sensorial inner ear epithelia secondary to different injuries. Isolation, cultivation and than in vitro differentiation of vestibular stem cells could become a regenerative implant for acquired hearing loss. These were the motives that determined us to try to isolate, cultivate and finally differentiate vestibular stem cells from vestibular epithelia.Utricles from 7 days old mice NMRI were harvested, the otolites were removed, the utricles were trypsinized in order to isolate cells. Obtained cells were cultivated at 37ºC and 5% CO2 in DMEM with F12 Nutrient mixture, B27, N2 supplement. Pluripotency of obtained spheres was established with the help of stem cell markers Nanog and Oct-4. For identification of progenitor cells we used the marker, which reveals the gene which encodes the protein nestin. In all experiments we obtained floating colonies called spheres, formed by mitotic multiplying. For testing the pluripotency of spheres we used Nanog and Oct-4, two transcription factors that are expressed at high levels in stem cells and that we found to be expressed in our spheres. The presence of nestin mRNA in cells composing the spheres showed that these progressed to a progenitor cell stage.We concluded that utricular epithelia in 7 days old mice contains sufficient stem cells that can be cultivated and that can be later differentiated.