In a significant advancement for sensory science, researchers at Tufts University School of Medicine and the Graduate School of Biomedical Sciences (GSBS) have unveiled a new, three-dimensional model that provides unprecedented insight into the regeneration of nerve tissue within the nose. This discovery has led to a major shift in the scientific understanding of olfactory health: a specific type of stem cell, long assumed to be dormant, has been identified as a critical player in maintaining the sense of smell.<\/p>\n
Unlike the neurons found in the central nervous system\u2014which are notoriously difficult to repair once damaged\u2014the sensory neurons in the nasal cavity possess a remarkable, lifelong capacity for regeneration. This biological resilience allows humans to recover their sense of smell even after exposure to environmental toxins or respiratory viruses. However, this process is not infallible. Chronic viral infections, such as those caused by COVID-19, long-term exposure to harmful particulates, and the natural physiological decline associated with aging can severely impair these neurons. When this regenerative machinery falters, the result is often a partial or complete loss of smell, a condition that can have profound impacts on a patient\u2019s quality of life, nutritional intake, and emotional well-being.<\/p>\n
To better understand why this repair process eventually fails, the Tufts research team, led by senior author Brian Lin, a research assistant professor in the Department of Developmental, Molecular and Chemical Biology, developed a novel, easy-to-create, three-dimensional olfactory tissue mouse model. Known as an organoid, this miniature, lab-grown tissue structure allows scientists to observe the continuous formation of neurons in a controlled environment. By recreating the nasal microenvironment, the team has been able to pinpoint the precise mechanisms that drive tissue renewal and identify the factors that cause the process to decline over time.<\/p>\n
The study, which was recently published in the journal Cell Reports Methods<\/em>, provides a detailed look at the complex interplay between two primary types of stem cells found in the nasal lining: horizontal basal cells (HBCs) and globose basal cells (GBCs). Traditionally, the scientific community viewed these two cell populations through a narrow lens, often characterizing HBCs as largely quiescent or "dormant" cells that only activate during extreme injury. The new research, however, challenges this long-standing assumption.<\/p>\n "Our research suggests that these two stem cells may be interdependent," explains Dr. 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 Through their organoid model, the researchers identified a specific subpopulation of HBCs, which are distinguished by their production of the protein KRT5. These cells do not merely sit in reserve; rather, they actively participate in the orchestration of new olfactory neurons. By selectively depleting these KRT5-producing HBCs from the organoid cultures, the researchers observed a dramatic impairment in the generation of new nerve tissue. This finding effectively reclassifies these cells from passive bystanders to essential architects of the nasal regenerative process.<\/p>\n The study further utilized the model to explore the effects of aging on this cellular machinery. By growing cells from mice of different ages within the organoid system, the team was able to document a clear decline in the regenerative capacity of older tissue. Dr. Lin notes that preliminary observations point toward a reduction in the GBC population as a primary driver of this age-related decline. While the researchers emphasize that further investigation is required to definitively confirm this hypothesis, the finding opens the door to potential future therapies aimed at rejuvenating these stem cell populations to restore sensory function in older adults.<\/p>\n A primary priority for the research team was ensuring that their new model was accessible to the broader scientific community. Juliana Gutschow Gameiro, the study\u2019s lead author and a former Ph.D. student who visited the GSBS from the State University of Londrina in Brazil, played a pivotal role in this effort. According to Dr. Lin, Gameiro was deeply committed to developing a protocol that could be replicated in laboratories with limited funding or specialized equipment.<\/p>\n This accessibility is particularly timely. The global surge in interest regarding olfactory health\u2014spurred by the widespread loss of smell associated with COVID-19, as well as the increasing prevalence of neurodegenerative conditions like Parkinson\u2019s disease\u2014has led to a massive influx of researchers from various disciplines entering the field. <\/p>\n "We wanted to develop an easy-to-use model so that non-stem cell biologists and those working in labs with limited resources could use it to better understand how olfactory neurons regenerate and what happens that causes that process to diminish or fail completely," Dr. Lin says. By lowering the barrier to entry, the team hopes to accelerate the pace of discovery, allowing scientists worldwide to test hypotheses and investigate the molecular triggers of olfactory dysfunction without the need for prohibitively expensive or complex experimental setups.<\/p>\n The ultimate ambition of the Tufts team is to translate the success of their mouse-tissue model into a human organoid. Such a model would represent a significant leap forward in pre-clinical research, providing a platform to screen pharmaceutical drugs for the treatment of olfactory loss. Organoids are increasingly viewed as a superior alternative to traditional animal models or basic cell cultures; they offer a more accurate representation of human organ biology while being faster, less expensive, and more ethically straightforward than testing on whole animals.<\/p>\n However, moving from a mouse model to a human one presents a unique set of technical hurdles. Collecting pure olfactory tissue from humans is inherently challenging. Currently, the standard procedure involves anesthetizing a patient and inserting a small brush\u2014similar in design to a COVID-19 test wand\u2014deep into the nasal cavity to retrieve cells. In this process, the collected sample is often a heterogeneous mix of respiratory stem cells and olfactory stem cells, which are notoriously difficult to separate.<\/p>\n "It’s challenging to get pure olfactory tissue from humans," Dr. Lin notes. Because the respiratory and olfactory cells are collected simultaneously during the standard brushing procedure, the resulting culture can be contaminated by the more dominant respiratory cell types, which can obscure the results or impede the growth of the delicate olfactory neurons.<\/p>\n The research team is now focused on overcoming this bottleneck. Their current challenge involves developing a simple, cost-effective technique to effectively isolate human olfactory stem cells from these mixed samples and provide the specific conditions required to coax them to flourish in a laboratory setting. If successful, this would provide researchers with a robust, human-derived tool to investigate the cellular basis of smell loss in real-time. By bridging the gap between basic stem cell biology and clinical application, the team at Tufts University aims to turn these fundamental discoveries into tangible treatments for the millions of people worldwide who live with a diminished or absent sense of smell. As the team continues to refine their techniques, the potential for restoring a vital sensory connection to the world remains a primary, achievable goal for future medical research.<\/p>\n","protected":false},"excerpt":{"rendered":" In a significant advancement for sensory science, researchers at Tufts University School of Medicine and the Graduate School of Biomedical Sciences (GSBS) have unveiled a new, three-dimensional model that provides unprecedented insight into the regeneration of nerve tissue within the nose. This discovery has led to a major shift in the scientific understanding of olfactory […]<\/p>\n","protected":false},"author":1,"featured_media":3910,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[650],"tags":[1823,2683,378,652,451,2105,243,4753,678,2673,658,659,2671,651],"class_list":["post-3911","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-health-and-wellness","tag-breakthrough","tag-cell","tag-discovery","tag-fitness","tag-health","tag-hope","tag-offers","tag-olfactory","tag-research","tag-restoring","tag-sense","tag-smell","tag-stem","tag-wellness"],"_links":{"self":[{"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts\/3911","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=3911"}],"version-history":[{"count":0,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts\/3911\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/media\/3910"}],"wp:attachment":[{"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3911"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3911"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3911"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}A Scalable Model for Global Research<\/h3>\n
The Path Toward Human Organoids<\/h3>\n