Stem Cells and the Sense of Smell
Posted on December 28, 2017
Researchers at Boston’s Tufts University School of Medicine may have new insights into how to minimize some of the consequences and impact of getting older after a recent study on the aging process and its effects on the sense of smell.
Researchers from the university’s Developmental, Molecular and Chemical Biology Department analyzed how nasal adult stem cells age and affect the ability to smell.
Many older adults experience a decrease in their ability to smell as they age, most notably during their 60s.
In addition to age, other factors that can impact the ability to smell include the use of some medications, drug use, injury, and illnesses such as cancer, Alzheimer’s disease and multiple sclerosis.
Some individuals lose their sense of smell entirely as a result of aging, a condition known as anosmia.
While changes in medications, diet and other therapies may reverse the loss of smell caused by certain conditions, there is currently no cure for the loss of smell due to aging.
The ability to smell is intimately connected to the ability to taste, and when the nose stops working correctly, a loss of smell may mean changes in dietary habits, which could negatively impact the nutritional health of some individuals and put them at risk for serious health issues.
For many older adults, the loss of smell also means depression and a reduced quality of life
Stem Cells and the Sense of Smell
The goal of the Tufts study was to increase the number of nasal adult stem cells in hopes of using them to restore the ability to smell.
To increase the number of nasal adult stem cells, the scientists working on the project created a pharmaceutical preparation designed to encourage stem cell proliferation once placed in the nasal passage.
The Tufts researchers were able to increase the number of stem cells by inducing stem cell regeneration in the nasal tissue of mice.
About Adult Stem Cells
Adult stem cells are primal, unspecialized cells with the ability to differentiate into many different types of cells and tissues.
Adult stem cells also have the ability to regenerate themselves without limit.
Progenitor cells are descendants of stem cells and are found in different tissue, like the nasal passages. Progenitor stem cells are more limited than adult stem cells regarding what types of tissues they can become, and unlike adult stem cells, progenitor stem cells cannot self-renew.
When the body is healthy, adult stem cells lay dormant. When the body is injured or under attack from illness, the stem cells awaken and begin repairs of damaged tissue.
The Tufts team capitalized on the healing potential of stem cells for their study. The researchers were able to regenerate human nasal adult stem cells in mice with injured nasal tissue.
The study authors also transplanted the nasal adult stem cells into the nasal passages of other mice where they were able to regenerate into the range of cells that make up the lining of the nasal passage, known as the olfactory epithelium.
The number of nasal adult stem cells increased when researchers added a pharmaceutical preparation to the noses of the mice.
Once in the nasal passages of the test mice, the transferred olfactory epithelium cells began behaving like stem cells.
The Impact of Adult Stem Cells on Aging
The Tufts researchers believe that the ability to change cell behavior has a significant impact on healing tissue damaged by aging in all parts of the body.
Stem cell therapy benefits other conditions, too.
“Using adult stem cells to regenerate damaged body tissue is ideal for individuals who cannot tolerate conventional medical treatment or do not respond to medical treatment,” said Dr. Joel Singer, M.D.
Singer is a New York physician who uses adult stem cell therapy to treat conditions that have no cure or effective treatment through conventional methods, such as scleroderma, myasthenia gravis, ALS, osteoarthritis and erectile dysfunction.
Tufts University, Health Sciences Campus. “When the nose doesn’t know: Can loss of smell be repaired? Researchers provide insight on Yamanaka factors and use of stem cells to address loss of smell in mouse study.” ScienceDaily. ScienceDaily, 4 December 2017.