In a significant breakthrough for regenerative medicine, a team of researchers at Tufts University School of Medicine and the Graduate School of Biomedical Sciences (GSBS) has identified a critical mechanism behind the body\u2019s ability to restore the sense of smell. By developing a sophisticated, three-dimensional model to study nasal nerve tissue, the scientists discovered that a specific population of stem cells\u2014previously dismissed as largely dormant\u2014plays a far more active and essential role in maintaining olfactory health than earlier models suggested.<\/p>\n
This discovery offers new insights into why the sense of smell can deteriorate due to viral infections, environmental toxins, or the natural progression of aging. The study, recently published in the journal Cell Reports Methods<\/em>, not only advances our biological understanding of olfactory neurons but also provides the scientific community with a new, accessible tool for testing future therapeutics.<\/p>\n The human olfactory system is a biological marvel. Unlike the rigid, fragile neurons of the central nervous system, the sensory neurons within the nasal cavity possess a unique and robust capacity for regeneration. Throughout a person\u2019s life, these cells are constantly exposed to the harsh, unpredictable external environment, necessitating a continuous turnover and replacement process. This ongoing cellular renewal is what allows the sense of smell to persist despite the daily bombardment of pollutants, allergens, and pathogens.<\/p>\n However, this delicate equilibrium is easily disrupted. Clinical conditions such as viral infections\u2014most notably the loss of smell associated with COVID-19\u2014prolonged exposure to toxic substances, and the biological decline associated with aging can overwhelm the regenerative capacity of these neurons. When the nose\u2019s ability to replicate these cells falters, the result is often a partial or total loss of smell, a condition that significantly impacts a patient\u2019s quality of life, nutritional health, and safety.<\/p>\n To better understand the mechanics of this decline, the Tufts research team, led by senior author Brian Lin, a research assistant professor in the Department of Developmental, Molecular and Chemical Biology, developed an innovative three-dimensional olfactory tissue model. By creating an "organoid"\u2014a miniature, simplified version of the tissue\u2014the team was able to observe the intricate dance of cellular communication in a controlled environment.<\/p>\n The research focuses on the interplay between two primary types of stem cells found in the nose: horizontal basal cells (HBCs) and globose basal cells (GBCs). Traditionally, scientific consensus held that GBCs were the primary drivers of neuronal production, while HBCs were viewed as a dormant "reserve" pool, only activated during instances of severe, catastrophic tissue injury.<\/p>\n However, the findings from the new organoid model challenge this long-standing hierarchy. "Our research suggests that these two stem cells may be interdependent," says Lin. "One type that we thought was largely dormant\u2014HBCs\u2014may actually play a crucial role in supporting the production of new neurons and the repair of damaged tissue."<\/p>\n By utilizing the 3D model, the team identified a specific subpopulation of HBCs, characterized by their production of the protein KRT5. These cells were observed actively facilitating the generation of new olfactory neurons, suggesting they are constant participants in tissue maintenance rather than passive observers. To confirm this, the researchers selectively depleted these KRT5-producing HBCs from the organoid cultures. The result was a dramatic and significant impairment in the generation of new neurons, underscoring that these cells are essential, active players in the regenerative cycle.<\/p>\n The study further investigated the impact of age on this process. By growing cells derived from mice of varying ages within the organoid model, the team observed a clear decline in the regenerative capacity of older cells. Lin suggests that this decline likely stems from a reduction in the GBC population over time. While this hypothesis requires further investigation, the team is optimistic that identifying the specific factors driving this age-related depletion could eventually lead to interventions designed to rejuvenate the nasal epithelium.<\/p>\n The development of this model was not merely an exercise in academic discovery; it was driven by a need for scientific democratization. Juliana Gutschow Gameiro, the lead author of the study and a former Ph.D. student visiting GSBS from the State University of Londrina in Brazil, played a pivotal role in designing a model that is both highly effective and remarkably easy to replicate.<\/p>\n "Because loss of smell is associated with COVID-19, as well as with Parkinson’s disease and other conditions, a much larger number of researchers from a variety of different fields have begun researching olfactory epithelial cells in the last few years," Lin explains. By prioritizing simplicity and cost-effectiveness, the team ensured that the model could be utilized in laboratories with limited funding or specialized equipment. The goal is to lower the barrier to entry, allowing non-specialist biologists to explore the mechanisms of olfactory regeneration and identify the precise "breakdowns" that lead to chronic anosmia.<\/p>\n The ultimate ambition of this line of research is the creation of a human olfactory organoid. Such a tool would revolutionize pre-clinical research, providing a reliable platform for high-throughput drug screening. Currently, developing treatments for olfactory loss is hindered by the lack of effective models; animal testing is often insufficient, and existing human cell cultures are difficult to maintain.<\/p>\n Organoids have already proven their value in other areas of medicine, providing researchers with accurate models of the lungs, kidneys, and other organs to test drug efficacy and safety. However, the nose presents a unique challenge. Obtaining pure olfactory tissue from human subjects is a delicate procedure, often requiring a brush\u2014similar to a standard COVID-19 nasal swab\u2014to be inserted deep into the nasal cavity. <\/p>\n "It’s challenging to get pure olfactory tissue from humans," Lin notes. During the collection process, the olfactory stem cells are frequently mixed with respiratory stem cells, and separating the two has historically proven difficult and labor-intensive. <\/p>\n As the Tufts team looks to the future, their primary objective is to refine a technique for the isolation and culture of human olfactory stem cells. Developing a simple, inexpensive method to separate these cells and encourage their growth in a laboratory setting would be the final bridge between their successful mouse-model findings and a practical, human-centered treatment for smell loss. By unlocking the secrets of the nose\u2019s hidden stem cells, the team is laying the groundwork for a new era of restorative medicine, offering hope to the millions of people worldwide who live with a diminished sense of smell.<\/p>\n","protected":false},"excerpt":{"rendered":" In a significant breakthrough for regenerative medicine, a team of researchers at Tufts University School of Medicine and the Graduate School of Biomedical Sciences (GSBS) has identified a critical mechanism behind the body\u2019s ability to restore the sense of smell. By developing a sophisticated, three-dimensional model to study nasal nerve tissue, the scientists discovered that […]<\/p>\n","protected":false},"author":1,"featured_media":2929,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[650],"tags":[2672,4385,652,451,2485,3893,1166,653,1647,2671,1165,1160,651],"class_list":["post-2930","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-health-and-wellness","tag-cells","tag-dormant","tag-fitness","tag-health","tag-hidden","tag-nasal","tag-regeneration","tag-researchers","tag-role","tag-stem","tag-tissue","tag-uncover","tag-wellness"],"_links":{"self":[{"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts\/2930","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2930"}],"version-history":[{"count":0,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts\/2930\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/media\/2929"}],"wp:attachment":[{"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2930"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2930"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2930"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}The Regenerative Power of the Nose<\/h3>\n
Unveiling the Role of Horizontal Basal Cells<\/h3>\n
An Accessible Model for Global Research<\/h3>\n
The Path Toward Human Organoids<\/h3>\n