In a significant advancement for regenerative medicine, researchers at the Tufts University School of Medicine and the Graduate School of Biomedical Sciences (GSBS) have unlocked new insights into the biological mechanics behind our sense of smell. By utilizing a newly devised, three-dimensional model to study the regeneration of nerve tissue within the nose, the team has discovered that a specific type of stem cell\u2014long presumed to be largely dormant\u2014actually plays a vital, active role in preserving olfactory function.<\/p>\n
The findings, published in the journal Cell Reports Methods<\/em>, offer a promising new avenue for understanding why the sense of smell often fades due to aging, viral infections such as COVID-19, or environmental toxin exposure. By shedding light on the cellular interdependencies that govern nasal tissue repair, this research provides a foundation for future therapies aimed at reversing sensory loss.<\/p>\n The human olfactory system is a marvel of biological resilience. Unlike the central nervous system, where damage is often permanent, the sensory neurons housed in the nasal cavity possess a remarkable, lifelong capacity for regeneration. Despite being in constant contact with the volatile external environment\u2014exposed to pathogens, pollutants, and shifting temperatures\u2014the olfactory epithelium is continuously renewed.<\/p>\n However, this delicate process is not infallible. When the rate of damage outpaces the rate of repair, or when the underlying stem cell populations become compromised, the result is a partial or total loss of smell, known clinically as anosmia or hyposmia. Given the recent surge in reports of smell loss associated with the COVID-19 pandemic, alongside established links between olfactory decline and neurodegenerative conditions like Parkinson\u2019s disease, the urgency for a deeper understanding of this regenerative process has never been greater.<\/p>\n To bridge this gap in knowledge, the Tufts research team, led by senior author Brian Lin, a research assistant professor in the Department of Developmental, Molecular and Chemical Biology, set out to create a more accessible research tool. They developed a three-dimensional olfactory tissue mouse model\u2014often referred to as an organoid\u2014designed specifically to mimic the complex cellular environment of the nose. This platform allows scientists to observe, in real-time, how neurons are formed and why the process falters as an organism ages.<\/p>\n At the heart of the study is the interaction between two distinct types of stem cells found within the nasal cavity: horizontal basal cells (HBCs) and globose basal cells (GBCs). Traditionally, the scientific consensus held that GBCs were the primary workhorses of neurogenesis, while HBCs were viewed as a dormant "reserve" pool, waiting in the wings to be activated only in the event of extreme injury.<\/p>\n The research conducted by the Tufts team challenges this paradigm. By tracking these cells within the 3D organoid environment, the researchers identified a specific subpopulation of HBCs marked by the production of the protein KRT5. Contrary to the belief that these cells are largely inactive, the study demonstrated that these KRT5-positive HBCs are essential for the ongoing support and generation of new olfactory neurons.<\/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 To confirm the importance of these cells, the researchers selectively depleted the KRT5-positive HBCs from the organoid cultures. The result was a dramatic impairment in the generation of new olfactory neurons, confirming that these cells are not merely bystanders, but fundamental architects of the regenerative process. This discovery fundamentally shifts the current understanding of how olfactory tissue maintains its integrity over a lifetime.<\/p>\n In addition to mapping the interaction between HBCs and GBCs, the team explored how these cellular dynamics shift as an organism ages. By culturing cells from mice of various ages within their 3D model, the researchers observed a clear decline in the regenerative capacity of older tissue. <\/p>\n "We found a decline in the ability of the older mice cells to generate new neurons," Lin notes. The team posits that this decline is likely tied to a diminishing population of GBCs as the organism grows older. While this hypothesis requires further investigation, the ability to observe this decline in a controlled, laboratory-grown organoid provides a vital starting point for future research. If the depletion of GBCs is indeed the primary driver of age-related smell loss, the next logical step will be to explore methods to stimulate or "rejuvenate" these cell populations to restore function.<\/p>\n A primary objective for the research team was to ensure that their findings could be easily replicated and utilized by the broader scientific community. Juliana Gutschow Gameiro, the study’s lead author and a former visiting Ph.D. student from the State University of Londrina in Brazil, played a pivotal role in the model’s design. Her focus was on creating a system that was not only robust but also affordable and simple to execute, even in laboratories with limited funding or specialized equipment.<\/p>\n "Because loss of smell is associated with COVID-19, as well as with Parkinson\u2019s 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," says Lin. "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."<\/p>\n The success of the mouse-derived organoid model marks a significant step forward in the democratization of olfactory research, allowing scientists across various disciplines to probe the mysteries of the nasal cavity without the need for prohibitively expensive or complex experimental setups.<\/p>\n While the mouse model has yielded transformative insights, the team\u2019s ultimate objective is to develop a human-derived olfactory organoid. Such a tool would be an invaluable asset for drug screening, potentially allowing for the identification of treatments that could help restore the sense of smell in patients suffering from permanent anosmia.<\/p>\n Organoids offer a clear advantage over traditional animal testing or standard cell cultures, as they provide a more accurate representation of human tissue architecture while being faster and less costly to produce. However, transitioning from mouse to human tissue presents a significant technical hurdle.<\/p>\n "It’s challenging to get pure olfactory tissue from humans," Lin explains. Currently, the collection process involves using a brush\u2014similar to those used in COVID-19 diagnostic tests\u2014to sample the nasal cavity. The issue, according to Lin, is that these samples often contain a mix of both respiratory and olfactory stem cells, which are notoriously difficult to separate.<\/p>\n The current challenge facing the team is to develop a simple, cost-effective technique to isolate these human olfactory stem cells and encourage them to proliferate in a laboratory setting. Once this hurdle is cleared, the potential for drug discovery and personalized medicine will be vast. By creating a patient-specific organoid, researchers could eventually test how different chemical compounds affect a specific individual’s ability to regenerate smell-sensing neurons, ushering in a new era of targeted, effective treatments for sensory loss. <\/p>\n As the Tufts team moves forward with this work, their findings serve as a reminder of how much remains to be discovered about the human body\u2019s most overlooked regenerative systems. With this new 3D model, the once-dormant mystery of nasal cell regeneration is finally beginning to reveal its secrets.<\/p>\n","protected":false},"excerpt":{"rendered":" In a significant advancement for regenerative medicine, researchers at the Tufts University School of Medicine and the Graduate School of Biomedical Sciences (GSBS) have unlocked new insights into the biological mechanics behind our sense of smell. By utilizing a newly devised, three-dimensional model to study the regeneration of nerve tissue within the nose, the team […]<\/p>\n","protected":false},"author":1,"featured_media":3842,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[650],"tags":[1823,2672,652,451,2485,656,3893,2247,6037,666,658,659,2671,651],"class_list":["post-3843","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-health-and-wellness","tag-breakthrough","tag-cells","tag-fitness","tag-health","tag-hidden","tag-model","tag-nasal","tag-potential","tag-restore","tag-reveals","tag-sense","tag-smell","tag-stem","tag-wellness"],"_links":{"self":[{"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts\/3843","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=3843"}],"version-history":[{"count":0,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts\/3843\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/media\/3842"}],"wp:attachment":[{"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3843"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3843"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3843"}],"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
Insights into Aging and Cellular Decline<\/h3>\n
An Accessible Model for Global Research<\/h3>\n
The Path Toward Human Organoids<\/h3>\n