Objectives: We sought to develop a new therapeutic strategy for degeneration of olfactory receptor neurons (ORNs).
Methods: We transplanted into Balb/C mice, locally by transnasal injection and systemically via the tail vain, BrdU-labeled bone marrow stem cells, also known as NRGs, which have the ability to differentiate into neural cells. Bone marrow stem cells engrafted into the olfactory epithelium were examined immunohistochemically.
Results: Compared with previous studies, in which bone marrow was transplanted rather than bone marrow stem cells, migration of transplanted bone marrow stem cells into the olfactory epithelium was observed earlier, and engraftment rates were significantly higher. However, migrated bone marrow stem cells were positive for GAP43 but not for olfactory marker protein.
Conclusions: These results suggest that engrafted cells had differentiated into premature, but not mature, ORNs. Further experiments using autologous bone marrow stem cells in combination with various growth factors and/or neurotrophic factors should aid the development of new therapeutic methods for degenerated ORNs.