Stem-cell therapy found to establish sense of smell in mice with non-functioning sensory neurons.
Approximately 15% of the US population suffers from anosmia, the inability to smell. This disorder can be caused by several factors including colds, head trauma, and genetic disorders; with many unfortunate side effects such as a loss of appetite, addition of more salt/sugar to food, and inability to sense dangerous smoke/chemicals.
Researchers at the University of Miami Miller School of Medicine found that cellular replacement therapy is effective at improving the sense of smell in mice with non-functioning sensory neurons.
The study used a genetic mouse model that lacked cilia on olfactory sensory neurons, rendering them unable to smell. Nose drops containing globose basal cells (stem cells that replace damaged/old olfacory sensory neurons) were administered, and found to successful graft to produce mature olfactory sensory neurons with projections to the olfactory bulb. These mice were also reactive to aversive scents unlike the untreated mice. No tumor growth was observed in mice treated with stem cell therapy.
"We were a bit surprised to find that cells could engraft fairly robustly with a simple nose drop delivery. To be potentially useful in humans, the main hurdle would be to identify a source of cells capable of engrafting, differentiating into olfactory neurons, and properly connecting to the olfactory bulbs of the brain. Further, one would need to define what clinical situations might be appropriate, rather than the animal model of acute olfactory injury."
As anosmia can be caused by a variety of different factors, the researchers at the university of Miami Miller School of Medicine hope to investigate the different causes of anosmia to determine if stem-cell based therapy is a feasible treatment option for each.