Characterization of human adult olfactory epithelium-derived stem cells

Our lab has developed techniques for the harvest and culture of adult human olfactory epithelium (OE), which generate cellular spheroids. Subculture of the spheroids results in a population of highly mitotic nestin-positive neural progenitors. The studies described in this dissertation characterize these adult OE-derived neurosphere forming cells (NSFCs). The therapeutic potential of NSFCs includes autologous transplantation, where minimal donor material is isolated, expanded, and lineage restricted prior to re-implantation. This strategy circumvents the ethical issues that arise with embryonic or fetal tissues and eliminate histocompatibility concerns.; To evaluate the mitotic capacity of the NSFCs, telomerase activity, which remains high in progenitors, was determined by ELISA of NSFC lines and passages. Furthermore, SS-DNA levels were evaluated because progenitors express low apoptotic levels. Telornerase and apoptotic activities remained constant irrespective of donor age, culture duration, or sex. Nine caspases critical in apoptosis were evaluated using microarrays, comparing cells across a broad passage range. Caspase activity remained low and equivalent in all passages studied.; Immunohistochemical study demonstrated that each NSFC-line possessed equivalent percentages of TrkA and TrkB, the receptors for NGF and BDNF, respectively; none were immunopositive for TrkC, the receptor for NT-3. All NSFC-lines contained mRNAs capable of producing the neurotrophins NGF, BDNF and NT-3, as well as CNTF, a growth factor associated with neuronal development. Intracellular levels of NGF, BDNF and NT-3 were similar the lines. Only BDNF was released into the medium. No CNTF was demonstrated within the cells or the surrounding medium, although the CNTF mRNA was detected in all lines.; These studies have demonstrated that NSFCs can be obtained from individual donors, irrespective of their age or sex. Furthermore, once generated the lines remain equivalent in all parameters evaluated, even though substantial variation of time in culture was required for development. The lines exhibited equivalent capacities for the expression of neurotrophic factors. In addition to the accessible adult location of the OF, which facilitates biopsy without damaging surgery, it allows autologous transplantation, eliminating immunosuppression and ethical controversy associated with embryonic stem cells.