A gradual loss or impairment of our sense of smell is a natural part of the normal ageing process. As we get older, many of us will experience a decline in our olfactory function, this will often result in a compromised or complete loss of smell. This in turn, affects the sense of taste. Loss of either, or both of these senses can significantly impact quality of life, and be hazardous to health and nutritional status.
This loss of smell is largely caused by a slow loss of stem cells in the nasal tissue that are present in young people, but lessen in number with age.
To date there have been no treatment options available to repair a person’s sense of smell.
Now, researchers at Tufts University School of Medicine in Boston are investigating the behaviour of stem cells related to the sense of smell in older people. Their research could be a step in the right direction to preventing deterioration and loss of smell in the future.
Regenerating nasal tissue
The research, led by Dr. James E. Schwob, managed to provide the first evidence that it is possible to regenerate nasal tissue in mice, therefore enlarging the population of adult stem cells.
Past research has shown that stem cells might regenerate in response to injury as part of the natural healing process. Dr, Schwob and his team tested this theory on mice and found that human stem cells regenerated in mice with injured nasal tissue. Perhaps more encouragingly, when they were transplanted into other mice, they were able to regenerate into different cell types.
Similarities can be seen between this study, and the Nobel Prize-winning approach developed by Dr. Shinya Yamanaka. Unlike Yamanaka, who induced cells taken from adult tissues to behave like embryonic stem cells by forcing them to express four genes, Schwob’s approach determined that only two of these four factors were critical to transforming the olfactory cells.
“The direct restoration of adult stem cells has implications for many types of tissue degeneration associated with aging, though we are several years away from designing actual therapies based on this work. The olfactory epithelium is a singularly powerful model for understanding how tissues regenerate or fail to do so,”
said Jim Schwob, M.D./Ph.D., a professor of Developmental, Molecular & Chemical Biology at Tufts University and senior author of the study.
“If we can restore the population of stem cells in the olfactory epithelium by regenerating them or by administering the right drug as a nasal spray, we may be able to prevent deterioration in the sense of smell,” he continued.