Abstract:

Objective    To observe the effects of nerve tissue committed stem cell (NTCSCs) transplantation in rats with injury of acoustic nerve. Methods    Bone marrow NTCSCs, transfected by green fluorescent protein (EGFP) gene, were transplanted into the left ear cochlea modiolus of rats  with specific coiling neuronal  injury, while the right ears were treated as self control with injection of same volume of PBS solution.  Group A, a control group, as well as other all the experimental groups, including group B, C, D, and E, were injected with the same volume of PBS solution. The cochlear axial slices were observed under fluorescence microscope after HE staining. The survivorship, distribution and expression of NTCSCs were observed. The threshold of ABR and DPOAE amplitude changes were detected at 1 week, 2 weeks and 1 month respectively after the injection. Results    Bone marrow NTCSCs transfected by green fluorescent protein (EGFP) gene in the  cochlear slices of the group C were dispersed in the lacouna of the tympanic canal of cochlea, while NTCSCs were dispersed in the basal membrane and Corti′s organ in the group D, butaggregated in the group E with two or three cells and its location was close to the basal membrane and Corti′s organ, which showed good distribution and tendency of migratory behavior. As the time of bone marrow NTCSCs transplantation going by, the number of Nestin (+) cells significantly increased (P<0.05) while Myosin Ⅶ a (+) showed no significant change in the number of cells (P>0.05). Meanwhile,  the threshold of ABR and  DPOAE amplitude all improved significantly(all P<0.05). Conclusion    Bone marrow NTCSCs transplanted to cochlea could gradually differentiate into spiral ganglion neuron (SGNs), which  plays a role in repairing the damage of auditory nerve.

Key words: Sensorineural deafness, Spiral ganglion neuron, Auditory neuropathy, Nerve tissue committed stem cell