A new study has examined the ability of olfactory neural stem cells to differentiate into different cell types and the efficacy of this stem cell population in regenerative treatments. Olfactory neural stem cells are highly proliferative (they grow fast) and they are easily harvested by means of a biopsy procedure that is minimally invasive. Because these cells are constantly replaced throughout someone’s lifetime, they are quickly replaced, and can even be grown in tissue culture.
Dr. Andrew Wetzig of the King Faisal Specialist Hospital and Research Centre in Riyadh, Saudi Arabia, who was the leading author of this study said: “There is worldwide enthusiasm for cell transplantation therapy to repair failing organs. The olfactory mucosa of a patient’s nose can provide cells that are potentially significant candidates for human tissue repair.”
These studies utilized rats as the preferred model system. The olfactory neural stem cells in rats seem to have rather similar characteristics to those in humans. According the Wetzig, “Previously, we found that they (i.e., olfactory neural stem cells) have performed well in preclinical models of disease and transplantation and seem to emulate a wound healing process where the cells acquire the appropriate phenotype in an apparently orderly fashion over time.”
When grown in culture, the olfactory stem cells form clusters of cells that grow as hollow balls of cells called “neurospheres.” These neurospheres contain stem cells that have the ability to differentiation into several different cell types. The specific cell type formed by the stem cells in the neurospheres is determined by specific signals from the immediate environment. Wetzig noted that olfactory stem cells grew well in culture, but when they were transplanted, the olfactory neural stem cells differentiated into the cell types that surrounded them. Therefore, the olfactory stem cells seemed to be able to sense their environment, and then assume the same cellular identity as their immediate neighbors.
While such work must be replicated with human olfactory stem cell before they can be considered for human clinical trials, such results are certainly encouraging.