Jovana Drinjakovic / en Growing up with a dog may be good for your gut health: Study /news/growing-dog-may-be-good-your-gut-health-study <span class="field field--name-title field--type-string field--label-hidden">Growing up with a dog may be good for your gut health: Study</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2024-09/GettyImages-1395719605-crop.jpg?h=81d682ee&amp;itok=I9qLxy8N 370w, /sites/default/files/styles/news_banner_740/public/2024-09/GettyImages-1395719605-crop.jpg?h=81d682ee&amp;itok=ueHimtCu 740w, /sites/default/files/styles/news_banner_1110/public/2024-09/GettyImages-1395719605-crop.jpg?h=81d682ee&amp;itok=rN9vIX42 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2024-09/GettyImages-1395719605-crop.jpg?h=81d682ee&amp;itok=I9qLxy8N" alt="a young boy with a dog lying down in a field"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>rahul.kalvapalle</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2024-09-26T10:44:39-04:00" title="Thursday, September 26, 2024 - 10:44" class="datetime">Thu, 09/26/2024 - 10:44</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"><p><em>Living with a dog between ages five and 15 is associated with reduced risk of developing Crohn’s disease, according to new research from Sinai Health and U of T (photo by&nbsp;Kseniya Starkova/Getty Images)&nbsp;</em></p> </div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/department-immunology" hreflang="en">Department of Immunology</a></div> <div class="field__item"><a href="/news/tags/department-medicine" hreflang="en">Department of Medicine</a></div> <div class="field__item"><a href="/news/tags/sinai-health" hreflang="en">Sinai Health</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/lunenfeld-tanenbaum-research-institute" hreflang="en">Lunenfeld-Tanenbaum Research Institute</a></div> <div class="field__item"><a href="/news/tags/mount-sinai-hospital" hreflang="en">Mount Sinai Hospital</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">Research from Sinai Health and U of T found early exposure to dogs is linked to a healthier gut and reduced risk of developing Crohn's disease</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Dog lovers can attest to the range of benefits that come with having a canine companion, but improved gut health likely isn’t one of them.</p> <p>That may be about to change following research from Sinai Health and the Ƶ that&nbsp;shows exposure to dogs during childhood is linked to beneficial changes in gut bacteria, gut permeability and blood biomarkers.</p> <p>The study, <a href="https://www.clinicalkey.com/#!/content/playContent/1-s2.0-S1542356524004506?returnurl=https:%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1542356524004506%3Fshowall%3Dtrue&amp;referrer=https:%2F%2Fwww.researchgate.net%2F">published in&nbsp;<em>Clinical Gastroenterology and Hepatology</em></a>, found living with a dog between ages five and 15 is associated with a healthier gut microbiome and reduced risk of developing Crohn’s disease.</p> <p>The research shines new light on how environmental factors influence the onset of Crohn’s – an inflammatory bowel condition – and could inform future prevention strategies.</p> <p>For the study, researchers led by <strong>Kenneth Croitoru</strong> and <strong>Williams Turpin</strong> of Mount Sinai Hospital’s <a href="https://www.sinaihealth.ca/areas-of-care/inflammatory-bowel-disease">Centre for Inflammatory Bowel Disease (IBD)</a> investigated how dozens of environmental factors impact the likelihood of developing Crohn’s as part of their overarching effort to be able to predict those at risk and potentially intervene early.</p> <p>“The idea behind predicting someone's risk of disease is that you can then also begin to understand who you might want to do something to try and prevent disease,” says Croitoru, a clinician-scientist at the&nbsp;Lunenfeld-Tanenbaum Research Institute&nbsp;(LTRI), part of&nbsp;Sinai Health, and a professor of medicine and immunology at U of T’s Temerty Faculty of Medicine.</p> <p>Croitoru notes the study doesn’t reveal why living with a dog makes someone less prone to Crohn’s disease. “We have established associations between environmental factors and Crohn’s and are now trying to understand how these environmental factors affect the triggering of the disease,” says Croitoru, who is also a gastroenterologist at Mount Sinai Hospital.</p> <p>The study also found living with a large-sized family in the first year of life to reduce the likelihood of getting Crohn’s. It also found people who lived with a bird at the time of study were more likely to develop the disease.</p> <p>Caused by inflammation in the gastrointestinal tract, Crohn’s disease can have far-reaching consequences on overall health and well-being. Its incidence among children under 10 has doubled since 1995, while the annual cost of inflammatory bowel disease to Canada is estimated at $5.4 billion per year, according to Crohn’s and Colitis Canada, a national non-profit.</p> <p>The likelihood of getting Crohn’s is strongly influenced by genetics, but the environment also plays a role, says Croitoru, who holds the Canada Research Chair in Inflammatory Bowel Diseases. While we can’t change our genes, we can modify our surroundings and diet, for example, to potentially prevent the disease from occurring.</p> <p>These findings come from the <a href="https://www.gemproject.ca/">Genetic, Environmental and Microbial (GEM) Project</a>, the largest study of its kind that seeks to identify potential triggers of Crohn’s disease.</p> <p>Coordinated at Mount Sinai Hospital since 2008, the GEM Project has been collecting comprehensive medical and lifestyle data from over 5,000 healthy first-degree relatives of people who have Crohn’s and come from all over the world, including Australia, Canada, Israel, New Zealand, the U.K. and the U.S.</p> <p>The project is funded by Crohn’s and Colitis Canada, the Canadian Institutes of Health Research and the Helmsley Charitable Foundation.</p> <p>In the 15 years since the study began, over 120 people have developed the disease. “By understanding what is different about those who develop the disease, we should be able to predict who is at risk,” says Croitoru.</p> <p>Previously, the group <a href="https://www.sinaihealth.ca/news/canadian-researchers-have-discovered-gut-bacteria-that-may-lead-to-crohns-disease/">identified&nbsp;differences in the microbiome and other biomarkers</a> in people who go on to develop Crohn’s and those who don’t.</p> <p>In another recent report published in&nbsp;Gastroenterology,&nbsp;<strong>Sun-Ho Lee</strong>, a clinician-scientist at Mount Sinai Hospital’s IBD Centre and an assistant professor at the&nbsp;Institute of Medical Science&nbsp;at Temerty Medicine, used available data and machine learning to develop an “<a href="https://www.gastrojournal.org/article/S0016-5085(24)05401-5/fulltext">integrative risk score</a>” that predicts the risk of Crohn’s with a high degree of accuracy.</p> <p>But risk prediction is only the first step, says Croitoru, whose ultimate goal is to be able to intervene and prevent the disease from starting.</p> <p>He and his team are now conducting research that seeks to devise and test strategies for prevention by, for example, adding supplements to the diet to promote a healthy microbiome.</p> <p>“Sinai Health is committed to groundbreaking research and bringing those discoveries to patients," said&nbsp;<strong>Anne-Claude Gingras</strong>, director of LTRI and vice-president of research at Sinai Health.</p> <p>“By integrating genetic, environmental, and microbial data, Dr. Croitoru and colleagues are paving the way towards personalized intervention strategies that could significantly reduce the incidence of Crohn’s disease.”</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Thu, 26 Sep 2024 14:44:39 +0000 rahul.kalvapalle 309604 at New study identifies two critical genes in pancreatic tumours /news/new-study-identifies-two-critical-genes-pancreatic-tumours <span class="field field--name-title field--type-string field--label-hidden">New study identifies two critical genes in pancreatic tumours</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2024-07/10736_LTRI_Directors_20240531-167-crop.jpg?h=81d682ee&amp;itok=gOmyhOSn 370w, /sites/default/files/styles/news_banner_740/public/2024-07/10736_LTRI_Directors_20240531-167-crop.jpg?h=81d682ee&amp;itok=EDGdlYEQ 740w, /sites/default/files/styles/news_banner_1110/public/2024-07/10736_LTRI_Directors_20240531-167-crop.jpg?h=81d682ee&amp;itok=eLNdkM8G 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2024-07/10736_LTRI_Directors_20240531-167-crop.jpg?h=81d682ee&amp;itok=gOmyhOSn" alt="Daniel Schramek examines a petri dish"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>rahul.kalvapalle</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2024-07-25T10:46:33-04:00" title="Thursday, July 25, 2024 - 10:46" class="datetime">Thu, 07/25/2024 - 10:46</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"><p><em>A team led by Daniel Schramek, a researcher at the Lunenfeld-Tanenbaum Research Institute (LTRI), Sinai Health and U of T's Temerty Faculty of Medicine, identified two genes that are associated with fast-growing tumours in the pancreas (photo courtesy of Mount Sinai)</em></p> </div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/sinai-health" hreflang="en">Sinai Health</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/lunenfeld-tanenbaum-research-institute" hreflang="en">Lunenfeld-Tanenbaum Research Institute</a></div> <div class="field__item"><a href="/news/tags/cancer" hreflang="en">Cancer</a></div> <div class="field__item"><a href="/news/tags/molecular-genetics" hreflang="en">Molecular Genetics</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">The findings mark a significant step forward in research on pancreatic cancer, a disease that has seen little progress in treatment options</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Ƶ researchers have identified two genes that play a critical role in tumour growth in the pancreas – findings that have significant implications for understanding and treating pancreatic cancer.</p> <p>The tumour suppressor genes USP15 and SCAF1 were discovered by a research team led by <strong>Daniel Schramek</strong>, a senior investigator at the Lunenfeld-Tanenbaum Research Institute (LTRI) and deputy director of discovery research and Tony Pawson Chair in Cancer Research at Sinai Health.</p> <p>The team found that people who have mutations in these genes are more likely to develop fast-growing tumours – but these tumours are also more susceptible to chemotherapy. The findings, described in a study <a href="https://www.nature.com/articles/s41467-024-49450-3">published in <em>Nature Communications</em></a>, mark a significant step forward in research on pancreatic cancer, a disease that has seen little progress in treatment options.</p> <p>“While mutations in USP15 and SCAF1 make tumours more aggressive, they also sensitize tumours towards standard chemotherapy,” says Schramek, who is also an associate professor in the department of molecular genetics and Canada Research Chair in functional cancer genomics at the Temerty Faculty of Medicine.</p> <p>“And that means that you could stratify patients and they should have a better response to treatment.”</p> <p>The project was spearheaded by <strong>Sebastien Martinez</strong>, a former postdoctoral fellow at LTRI who is now a senior scientist at Centre de Recherche en Cancérologie de Lyon (CRCL) in France.</p> <p>Pancreatic cancer continues to have few treatment options with devastatingly low survival rates, under five years post-diagnosis. According to one estimate, pancreatic cancer could be the second leading cause of cancer deaths in the United States by 2040.</p> <p>Schramek's team achieved their breakthrough by leveraging advances in genomic medicine, specifically tumour DNA sequencing, to identify mutations and genome editing technologies.</p> <p>“Sequencing tumours allows you to find the genes that are affected and use that knowledge to develop treatments. But the problem is that every cancer has a plethora of mutations, and not all of them are disease-causing,” says Schramek.</p> <p>Cancers often feature common mutated genes in many patients, along with hundreds of less frequent mutations that appear in a smaller subset. While mutations in USP15 and SCAF1 were found in less than five per cent of patients, their effects on cancer remained unclear.&nbsp;</p> <p>Traditionally, tumour suppressor genes have been pinpointed by sequentially deleting genes in cancer cell lines and noting which deletions increase cell growth. However, these cell-based studies don't replicate the tumour's natural environment and interactions with the immune system, which are crucial for cancer progression. This likely explains why previous screens overlooked USP15 and SCAF1.</p> <p>A few years ago, Schramek's team developed a genome editing approach enabling them to remove hundreds of genes simultaneously from individual cells. This method helps identify genes that, when absent, trigger cancer in the natural body environment.</p> <p>Utilizing this technology, the Schramek lab targeted 125 genes recurrently mutated in patient pancreatic tumours and pinpointed USP15 and SCAF1 as crucial tumor suppressors and potentially prognostic factors for chemotherapy response.</p> <p>It just so happens that these genes are also absent in about 30 per cent of patients due to common genomic rearrangements in cancer.</p> <p>This finding indicates that as many as a third of pancreatic patients who lack these genes might benefit from chemotherapy and have better outcomes.</p> <p>“Historically, mutations in USP15 and SCAF1 would have been considered less important because they are not found in many patients,” Schramek says.&nbsp;“Our work shows that it is critical that we understand the functional consequences of these rare mutations as they can reveal new biology and therapeutic opportunities”</p> <p><strong>Anne-Claude Gingras</strong>, director of the Lunenfeld-Tanenbaum Research Institute and vice-president of research at Sinai Health, says the study “represents an important step forward in our understanding of the genes involved in pancreatic cancer.</p> <p>“It also shows how a cutting-edge technology developed at Sinai Health is enabling new discoveries with the potential to create benefits to patients.”&nbsp;</p> <p>This research was supported by funding from the Ontario Institute of Cancer Research, Wallace McCain Centre for Pancreatic Cancer, Princess Margaret Cancer Foundation, Terry Fox Research Institute, Canadian Cancer Society Research Institute, Pancreatic Cancer Canada and the Canadian Institute of Health.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Thu, 25 Jul 2024 14:46:33 +0000 rahul.kalvapalle 308548 at A master neuron controls movement in worms, with implications for human disease: Study /news/master-neuron-controls-movement-worms-implications-human-disease-study <span class="field field--name-title field--type-string field--label-hidden">A master neuron controls movement in worms, with implications for human disease: Study</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2024-05/C._elegans%2C_model_organism_in_life_sciences_%2828703152561-crop.jpg?h=81d682ee&amp;itok=7xz_y1bQ 370w, /sites/default/files/styles/news_banner_740/public/2024-05/C._elegans%2C_model_organism_in_life_sciences_%2828703152561-crop.jpg?h=81d682ee&amp;itok=RoYIX2BR 740w, /sites/default/files/styles/news_banner_1110/public/2024-05/C._elegans%2C_model_organism_in_life_sciences_%2828703152561-crop.jpg?h=81d682ee&amp;itok=sKDHxRCy 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2024-05/C._elegans%2C_model_organism_in_life_sciences_%2828703152561-crop.jpg?h=81d682ee&amp;itok=7xz_y1bQ" alt="&quot;&quot;"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2024-05-16T11:01:59-04:00" title="Thursday, May 16, 2024 - 11:01" class="datetime">Thu, 05/16/2024 - 11:01</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"><p><em>Researchers at the Lunenfeld-Tanenbaum Research Institute have revealed the crucial role of a neuron called AVA in controlling the worm C. elegans’s ability to shift between forward and backward motion ( photo by ZEISS Microscopy&nbsp;from Germany)&nbsp;</em></p> </div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/sinai-health" hreflang="en">Sinai Health</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/cell-and-systems-biology" hreflang="en">Cell and Systems Biology</a></div> <div class="field__item"><a href="/news/tags/faculty-arts-science" hreflang="en">Faculty of Arts &amp; Science</a></div> <div class="field__item"><a href="/news/tags/molecular-genetics" hreflang="en">Molecular Genetics</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">The discovery offers a major new insight into a neural circuit that scientists have studied since the inception of modern genetics.<br> </div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Researchers at&nbsp;Sinai Health&nbsp;and the Ƶ have uncovered a mechanism in the nervous system of the tiny roundworm <em>C. elegans </em>that<em>&nbsp;</em>could have significant implications for treating human diseases and advancing robotics.</p> <p>The&nbsp;study, led by&nbsp;<strong>Mei Zhen</strong>&nbsp;and colleagues at the&nbsp;<a href="https://www.lunenfeld.ca" target="_blank">Lunenfeld-Tanenbaum Research Institute</a>, was <a href="https://www.science.org/doi/10.1126/sciadv.adk0002" target="_blank">published in the journal <em>Science Advances</em></a> and reveals the crucial role of a specific neuron called AVA in controlling the worm’s ability to shift between forward and backward motion.</p> <p>Crawling towards food sources and swiftly reversing from danger is a matter of life and death for the worms. This type of behaviour, where two actions are mutually exclusive, is common in many animals including humans – we cannot sit and run at the same time, for example.</p> <p>Scientists long believed that control of movements in worms was due to straightforward reciprocal actions between two neurons: AVA and AVB. The former was thought to promote backward motion while AVB facilitated forward motion, with each neuron inhibiting the other to control movement direction.</p> <p>However, the new data from Zhen’s team challenge this notion, uncovering a more complex interaction where the AVA neuron plays a dual role. It not only instantly stops forward motion by inhibiting AVB, but also maintains a longer-term stimulation of AVB to ensure a smooth transition back to forward movement.</p> <p>The discovery highlights the AVA neuron’s ability to finely control movement through distinct mechanisms, depending on different signals and across different time scales.</p> <p>“In terms of engineering, this is a very economical design,” said Zhen, who is also a professor of&nbsp;molecular genetics&nbsp;in U of T’s Temerty Faculty of Medicine. “The strong, robust inhibition of the backward circuit allows the animals to respond to bad environments and escape. At the same time, the controller neuron continues to put in constitutive gas into the forward circuit to generate movement towards safer places.”</p> <p><strong>Jun Meng</strong>, a former PhD student in the Zhen lab who led the research, said understanding how animals transition between such opposing motor states is crucial for insights into how animals move as well as neurological disorder research – and that the worms provide a unique window into basic neural wiring that's to their simple, see-through bodies.</p> <p>The discovery that the AVA neuron plays such a dominant role offers a major new insight into the neural circuit that scientists have studied since the inception of modern genetics over half a century ago. The Zhen lab successfully leveraged cutting-edge technology to precisely modulate the activity of individual neurons and record data from living worms in motion.</p> <p>Zhen, who is also a professor of&nbsp;cell and systems biology&nbsp;at U of T’s Faculty of Arts &amp; Science, emphasizes the importance of interdisciplinary collaboration in this research. Meng performed key experiments, while neuronal electrical recordings were conducted by&nbsp;<strong>Bin Yu</strong>, a PhD student in&nbsp;<strong>Shangbang Gao</strong>’s lab at Huazhong University of Science and Technology in China.</p> <p><strong>Tosif Ahamed</strong>, a former post-doctoral researcher in the Zhen lab and now a Theory Fellow at the HHMI Janelia Research Campus in the United States, led mathematical modelling efforts that were crucial for testing hypotheses and gaining the new insights.</p> <p>The findings provide a simplified model to study how neurons can manage multiple roles in movement control – a concept that might extend to human neurological conditions.</p> <p>For example, AVA’s dual role depends on its electric potential, which is regulated by ion channels on its surface. Zhen is already exploring how similar mechanisms could be involved in a rare condition known as CLIFAHDD syndrome, caused by mutations in similar ion channels. Additionally, the new findings could inform the development of more adaptable and efficient robotic systems capable of complex movements.</p> <p>“From the origin of modern science to the forefront of today’s research, model organisms like <em>C. elegans</em> have been instrumental in peeling back the layers of complexity in our biological systems," said&nbsp;<strong>Anne-Claude Gingras</strong>, director of the Lunenfeld-Tanenbaum Research Institute, vice-president of research at Sinai Health and a professor of molecular genetics in U of T’s Temerity Faculty of Medicine.</p> <p>“This research is a great example of how much we can learn from simple animals, to then think about applying this new knowledge to advancing medicine and technology.”</p> <p>The research was supported by the Canadian Institute of Health Research, the Natural Sciences and Engineering Research Council of Canada, the National Natural Science Foundation of China and the European Research Council.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Thu, 16 May 2024 15:01:59 +0000 Christopher.Sorensen 307873 at Post-meal insulin surge not necessarily a bad thing: Study /news/post-meal-insulin-surge-not-necessarily-bad-thing-study <span class="field field--name-title field--type-string field--label-hidden">Post-meal insulin surge not necessarily a bad thing: Study</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2024-01/GettyImages-1434438081-crop.jpg?h=81d682ee&amp;itok=6tTvf07I 370w, /sites/default/files/styles/news_banner_740/public/2024-01/GettyImages-1434438081-crop.jpg?h=81d682ee&amp;itok=5QdIeMLo 740w, /sites/default/files/styles/news_banner_1110/public/2024-01/GettyImages-1434438081-crop.jpg?h=81d682ee&amp;itok=SYWrF02D 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2024-01/GettyImages-1434438081-crop.jpg?h=81d682ee&amp;itok=6tTvf07I" alt="man eating a big bowl of pasta, wine and salad"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2024-01-12T15:24:44-05:00" title="Friday, January 12, 2024 - 15:24" class="datetime">Fri, 01/12/2024 - 15:24</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"><p><em>(photo by&nbsp;Violeta Stoimenova/Getty Images)</em></p> </div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/sinai-health" hreflang="en">Sinai Health</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/banting-best" hreflang="en">Banting &amp; Best</a></div> <div class="field__item"><a href="/news/tags/diabetes" hreflang="en">Diabetes</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">Researchers explored the cardiometabolic implications of insulin response over the long term in a way that accounts for baseline blood sugar levels</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Researchers at Sinai Health and the Ƶ have unearthed new information about the relationship between insulin levels after eating and long-term heart and metabolic health – research that upends the notion that insulin surge following food intake is a bad thing.</p> <p>On the contrary, the researchers said, it could be an indicator of good health to come.</p> <p>Led by&nbsp;<strong>Ravi Retnakaran</strong>, clinician-scientist at the&nbsp;Lunenfeld-Tanenbaum Research Institute (LTRI), part of Sinai Health, the study – which was&nbsp;<a href="https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(23)00540-0/fulltext">published in the Lancet group’s online journal&nbsp;<em>eClinicalMedicine</em></a>&nbsp;– set out to explore how insulin levels after meals impact cardiometabolic health. While past research has yielded conflicting results, suggesting both harmful and beneficial effects, this new study aimed to provide a clearer picture over an extended period of time.</p> <p>“The suggestion has been made by some people that those insulin peaks have deleterious effects by promoting weight gain,” said Retnakaran, who is a professor in the&nbsp;department of medicine, the&nbsp;Institute of Medical Science&nbsp;and the&nbsp;Banting &amp; Best Diabetes Centre&nbsp;in U of T’s Temerty Faculty of Medicine. “Sometimes I see patients in the clinic who have adopted this notion&nbsp;– maybe from the internet or what they're reading&nbsp;– that they can't have their insulin level go too high.</p> <p>“[But] the science is just not conclusive enough to support this notion. Most studies on this topic were either conducted over a short period of time or were based on insulin measurements in isolation that are inadequate and can be misleading.”</p> <p>While it’s normal for insulin levels to rise after eating to help manage blood sugar, the concern is whether a rapid increase in insulin after a meal could spell bad health. Some believe an insulin surge, especially after eating carbohydrates, promotes weight gain and contributes to insulin resistance, which occurs when the body's cells don't respond well to insulin, making it harder to control blood sugar levels and increasing the risk of type 2 diabetes.</p> <p>Retnakaran’s team looked at cardiometabolic implications of insulin response over the long term in a way that accounts for baseline blood sugar levels. That’s key because each person has an individual insulin response that varies depending on how much sugar is in the blood.</p> <p>The study followed new mothers because the insulin resistance that occurs during pregnancy makes it possible to determine their future risk of type 2 diabetes. Over 300 participants were recruited during pregnancy, between 2003 and 2014, and underwent comprehensive cardiometabolic testing – including glucose challenge tests at one, three and five years after giving birth. The glucose challenge test measures glucose and insulin levels at varying times after a person has had a sugary drink containing 75 grams of glucose and following a period of fasting.</p> <p>While the test is commonly used by health professionals, it can be misleading if one does not account for baseline blood sugar. &nbsp;</p> <p>“It’s not just about insulin levels; it’s about understanding them in relation to glucose,” Retnakaran said, pointing out that this is where many past interpretations fell short. A better measurement, he said, is the corrected insulin response (CIR) that accounts for baseline blood glucose levels, and which is slowly gaining prominence in the field.</p> <p>The study revealed some surprising trends. As the corrected insulin response increased, there was a noticeable worsening in waist circumference, HDL (good cholesterol) levels, inflammation and insulin resistance&nbsp;– as long as one&nbsp;did not consider accompanying factors. However, these seemingly negative trends were accompanied by better beta-cell function. Beta cells produce insulin and their ability to do so is closely associated with diabetes risk. In other words, the better beta cells function, the lower the risk.</p> <p>“Our findings do not support the carbohydrate-insulin model of obesity,” said Retnakaran. “We observed that a robust post-challenge insulin secretory response – once adjusted for glucose levels – is only associated with the beneficial metabolic effects.”</p> <p>“Not only does a robust post-challenge insulin secretory response not indicate adverse cardiometabolic health, but rather it predicts favorable metabolic function in the years to come.”</p> <p>In the long run, higher corrected insulin response levels were linked with better beta-cell function and lower glucose levels, without correlating with BMI, waist size, lipids, inflammation or insulin sensitivity and resistance. Most importantly, women who had the highest CIR had a significantly reduced risk of developing pre-diabetes or diabetes in the future.</p> <p>“This research challenges the notion that high post-meal insulin levels are inherently bad and is an important step forward in our understanding of the complex roles insulin plays in regulation of metabolism,” said&nbsp;<strong>Anne-Claude Gingras</strong>, director of LTRI and vice-president of research at Sinai Health, who is also a professor of&nbsp;molecular genetics&nbsp;at Temerty Medicine.</p> <p>Retnakaran hopes the team’s findings will reshape how medical professionals and the public view insulin's role in metabolism and weight management.</p> <p>“There are practitioners who subscribe to this notion of higher insulin levels being a bad thing, and sometimes are making recommendations to patients to limit their insulin fluctuations after the meal. But it’s not that simple,” he said.</p> <p>The research was supported by grants from the Canadian Institutes of Health Research.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Fri, 12 Jan 2024 20:24:44 +0000 Christopher.Sorensen 305282 at Study finds new roles for gut hormone GLP-1 in the brain /news/study-finds-new-roles-gut-hormone-glp-1-brain <span class="field field--name-title field--type-string field--label-hidden">Study finds new roles for gut hormone GLP-1 in the brain</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2024-01/UofT93566_2022-07-18-Daniel-Drucker-8_Polina-Teif-story.jpg?h=c4bddbb2&amp;itok=slq9BBcH 370w, /sites/default/files/styles/news_banner_740/public/2024-01/UofT93566_2022-07-18-Daniel-Drucker-8_Polina-Teif-story.jpg?h=c4bddbb2&amp;itok=_wgkQTRT 740w, /sites/default/files/styles/news_banner_1110/public/2024-01/UofT93566_2022-07-18-Daniel-Drucker-8_Polina-Teif-story.jpg?h=c4bddbb2&amp;itok=2uWs06mX 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2024-01/UofT93566_2022-07-18-Daniel-Drucker-8_Polina-Teif-story.jpg?h=c4bddbb2&amp;itok=slq9BBcH" alt="&quot;&quot;"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>rahul.kalvapalle</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2024-01-08T12:07:09-05:00" title="Monday, January 8, 2024 - 12:07" class="datetime">Mon, 01/08/2024 - 12:07</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"><p><em>University Professor Daniel Drucker's team looked at how GLP-1 drugs reduce inflammation, which is common in chronic metabolic diseases</em><em>&nbsp;(photo by Polina Teif)</em></p> </div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/sinai-health" hreflang="en">Sinai Health</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/lunenfeld-tanenbaum-research-institute" hreflang="en">Lunenfeld-Tanenbaum Research Institute</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">The findings show for the first time that there is a GLP-1-brain-immune axis that controls inflammation – even in peripheral organs that lack GLP-1 receptors</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>A research team led by <strong>Daniel Drucker</strong>, senior investigator at Sinai Health’s&nbsp;Lunenfeld-Tanenbaum Research Institute and <a href="https://www.provost.utoronto.ca/awards-funding/university-professors/complete-list-university-professors/">University Professor</a> in the department of medicine in the Ƶ’s Temerty Faculty of Medicine, has discovered a gut-brain-immune network that controls inflammation across the body and affects organ health.</p> <p>The&nbsp;findings, <a href="https://www.cell.com/cell-metabolism/fulltext/S1550-4131(23)00420-5#%20">published in <em>Cell Metabolism</em></a>,&nbsp;centre on the effects of glucagon-like peptide-1 (GLP-1) receptor agonists, or activators, which clinicians use to treat Type 2 diabetes and which have recently proven highly effective for weight loss.</p> <p>“One of the really interesting things about the GLP-1 drugs is that beyond the control of blood sugar and body weight, they also seem to reduce the complications of chronic metabolic disease,” said Drucker, who holds the BBDC-Novo Nordisk Chair in Incretin Biology.</p> <p>“We know from clinical studies that GLP-1 does all this amazing stuff in people, but we don’t fully know how it works,” said Drucker.</p> <p>To help answer this question, Drucker’s team looked at how GLP-1 drugs reduce inflammation, which is common in chronic metabolic diseases. Inflammation occurs when the immune system recognizes and removes foreign agents, such as viruses and bacteria, and promotes healing. In chronic form, however, it can persist without an external cause and lead to organ damage.</p> <p>Many researchers assumed that GLP-1 drugs dampen inflammation by interacting with GLP-1 receptors on immune cells. This is the case in the gut, where large numbers of immune cells are activated by GLP-1. But in other organs, the number of immune cells containing GLP-1 receptors is negligible, indicating another mechanism may be at play.</p> <p>“The strange thing is that you can’t find many GLP-1 receptors in all these other organs where GLP-1 seems to work,” said Drucker, whose earlier research showed how the GLP-1 gut hormone works at the molecular level and paved the way for several diabetes and weight-loss drugs, including Ozempic and Wegovy.</p> <p>Drucker and his team had a hint that the brain might be involved for two reasons: GLP-1 receptors are abundant there, and the brain and the immune system communicate with all organs in the body.</p> <p><strong>Chi Kin Wong</strong>, first author on the study and a postdoctoral scientist in the Drucker lab, induced systemic inflammation in mice by either injecting them with a bacterial cell wall component or a bacterial slur to induce sepsis — an extensive inflammation throughout the body that leads to organ damage.</p> <p>Remarkably, GLP-1 agonists reduced inflammation, but only when their receptors in the brain were left unblocked. When these brain receptors were pharmacologically inhibited or genetically removed in mice, the drugs’ ability to reduce inflammation was lost.</p> <p>The findings showed for the first time that there is a GLP-1-brain-immune axis that controls inflammation across the body independent of weight loss, even in peripheral organs devoid of GLP-1 receptors, said Drucker.</p> <p>Drucker has received some of the world’s most prestigious awards in the life sciences for his many findings on GLP-1, including the 2023 VinFuture Emerging Innovation Prize and the 2023 Wolf Prize in Medicine. As well, GLP-1-based diabetes drugs that emerged from Drucker’s early research were named <a href="https://www.science.org/content/article/breakthrough-of-the-year-2023#section_breakthrough">2023 Breakthrough of the Year</a> by the journal&nbsp;<em>Science</em>.</p> <p>“As the scientific community deservingly celebrates GLP-1 agonists and their impact, there are many unknowns left,” said&nbsp;<strong>Anne-Claude Gingras</strong>, director of the Lunenfeld-Tanenbaum Research Institute, vice-president of research at Sinai Health and professor in the department of molecular genetics at Temerty. “Dr. Drucker and his team have remained tenacious in their efforts to unpack how these drugs work, and this study deepens our understanding of metabolism and the complex brain-immune network that regulates it.”</p> <p>Drucker’s team is now trying to pinpoint the brain cells that interact with GLP-1. They are also looking at various mouse models of inflammation, including heart disease, atherosclerosis and liver and kidney inflammation, to establish whether the beneficial effects of GLP-1 are indeed mediated through the brain.</p> <p>Drucker said that understanding how GLP-1 dampens inflammation may open new avenues for reducing the complications associated with Type 2 diabetes and obesity.</p> <p>He added that the recognition of GLP-1 biology as&nbsp;<em>Science</em>’s&nbsp;2023 Breakthrough of the Year “highlights the expanding clinical impact of GLP-1, and the tremendous potential for basic scientific discovery to continuously improve human health.”</p> <p>The research was funded by the Canadian Institutes for Health Research and Novo Nordisk Inc.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Mon, 08 Jan 2024 17:07:09 +0000 rahul.kalvapalle 305212 at Scientists create ‘cloaked’ donor cell, tissue grafts that escape immune system rejection /news/scientists-create-cloaked-donor-cell-tissue-grafts-escape-immune-system-rejection <span class="field field--name-title field--type-string field--label-hidden">Scientists create ‘cloaked’ donor cell, tissue grafts that escape immune system rejection </span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2023-12/Nagy-portrait_larger-crop.jpg?h=afdc3185&amp;itok=0VqGp7HD 370w, /sites/default/files/styles/news_banner_740/public/2023-12/Nagy-portrait_larger-crop.jpg?h=afdc3185&amp;itok=zEOLlteu 740w, /sites/default/files/styles/news_banner_1110/public/2023-12/Nagy-portrait_larger-crop.jpg?h=afdc3185&amp;itok=wh9C7nyJ 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2023-12/Nagy-portrait_larger-crop.jpg?h=afdc3185&amp;itok=0VqGp7HD" alt="&quot;&quot;"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2023-12-06T11:16:29-05:00" title="Wednesday, December 6, 2023 - 11:16" class="datetime">Wed, 12/06/2023 - 11:16</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"><p><em>Andras Nagy, a senior investigator at Sinai Health’s&nbsp;Lunenfeld-Tanenbaum Research Institute (LTRI) and professor in U of T’s&nbsp;Temerty Faculty of Medicine, led research that created transplants in pre-clinical testing without the need for immune suppression</em></p> </div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/sinai-health" hreflang="en">Sinai Health</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/lunenfeld-tanenbaum-research-institute" hreflang="en">Lunenfeld-Tanenbaum Research Institute</a></div> <div class="field__item"><a href="/news/tags/medicine-design" hreflang="en">Medicine by Design</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">The findings could lead to advancements in cell therapies for type 1 diabetes and heart failure</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Researchers at&nbsp;Sinai Health&nbsp;and the&nbsp;Ƶ&nbsp;have developed a technology that may one day eliminate the need for immunosuppressive drugs in transplant patients.</p> <p>Through genetic modification of donor cells, the researchers successfully created transplants that persisted long-term in pre-clinical testing without the need for immune suppression.</p> <p>The findings raise hope that a similar strategy could be employed in human patients, potentially making transplantation safer and more widely available.</p> <p>“Our work paves the way for an ‘off-the-shelf’ supply of cells for therapies that could be safely given to many patients,” said&nbsp;<strong>Andras Nagy</strong>, a senior investigator at Sinai Health’s&nbsp;Lunenfeld-Tanenbaum Research Institute (LTRI) and professor in the department of obstetrics and gynaecology and the Institute of Medical Science at U of T’s&nbsp;Temerty Faculty of Medicine, who led the research.</p> <p>The study was&nbsp;<a href="https://www.nature.com/articles/s41551-023-01133-y">published in the journal&nbsp;<em>Nature Biomedical Engineering</em></a>.</p> <p>Immune rejection poses a major challenge in donor cell therapy, said Nagy, who is Canada Research Chair in Stem Cells and Regeneration and has done seminal work in the field. In such cases, the recipient’s immune system recognizes the transplanted cells as foreign invaders and launches an attack, leading to rejection.</p> <p>“Transplant and cell therapy patients are required to take immunosuppressive drugs&nbsp;– sometimes for the rest of their lives&nbsp;– to prevent their bodies from rejecting the transplant,” explained Nagy. The extended use of these drugs can lead to serious health issues, including recurring infections and an elevated cancer risk.</p> <p>Scientists worldwide have been exploring various solutions, including creating therapeutic cells from the patient’s own cells or encapsulating donor cells in inorganic material for protection.</p> <p>But these methods face challenges such as high costs, long preparation times and foreign body immune response, complicating their widespread and cost-effective application.</p> <p>Stem cells have the unique ability to divide indefinitely and give rise to specialized cells that form our organs. They make an ideal source for cell therapies as large numbers of cells can be obtained and converted into desired cell types to replace those lost to disease or injury.</p> <p>But there are major safety concerns: in addition to addressing immune-matching, scientists must ensure that no unwanted dividing cells remain in the transplant that could cause cancer in the future.</p> <p>Nagy, who established Canada’s first human embryonic stem cell line in 2005, has dedicated his career to engineering safeguards for future cell therapies. In 2018, his team <a href="https://www.sinaihealth.ca/news/new-discovery-a-built-in-killer-switch-eliminates-dividing-cells-from-lab-grown-transplant-tissue-to-improve-patient-safety/">published a landmark paper in&nbsp;<em>Nature</em></a>&nbsp;about&nbsp;a drug-inducible “kill-switch” called&nbsp;FailSafe&nbsp;that protects from cancer by eliminating unwanted proliferating cells in transplants.</p> <p>For the current study, postdoctoral researcher&nbsp;<strong>Jeff Harding</strong>&nbsp;and PhD student&nbsp;<strong>Kristina Vintersten-Nagy</strong>&nbsp;combined the kill-switch technology with a strategy they called “immune cloaking.”</p> <p>Nagy’s team selected eight key genes that regulate how the immune system responds to threats, including foreign cells. Forced overexpression of these genes in mouse embryonic stem cells prevented&nbsp;the immune system from recognizing them as foreign.</p> <p>The modification&nbsp;effectively created an immune cloak around the cells following their injection under the skin of genetically unmatched hosts.</p> <p>“Patient safety is paramount, and Dr. Andras Nagy is globally renowned for his sustained efforts to develop safeguards for future cell therapies,” said&nbsp;<strong>Anne-Claude Gingras</strong>, director of LTRI and vice-president of research at Sinai Health, and a professor of&nbsp;molecular genetics&nbsp;at Temerty Medicine.</p> <p>“This study demonstrates the combined potential of FailSafe and immune cloaking for the creation of a universal source of cells that could be applied to a multitude of diseases.”&nbsp;</p> <p>Uncloaked cells are typically rejected within 10 days of transplantation. In contrast, the cloaked cells persisted for more than nine months at the endpoint of the experiment. “This is the first time that we’ve been able to achieve this length of time without rejection in a fully functional immune system,” said Nagy, who is also a professor at Monash University in Australia.</p> <p>In another key finding, the researchers showed that unmodified cells can escape rejection when embedded into the tissue created by the cloaked donor cells below the skin surface. The protection extended to cells from another species, as shown by the ability of unmodified human cells to survive within a cloaked mouse graft.</p> <p>This suggests that modified cells also act as an immune-privileged implantation site for unmodified cells, with implications for interspecies transplants. Researchers&nbsp;at other institutions are exploring the potential of pigs as donors because their organs are very similar in size and function to humans.</p> <p>Building on this success, PhD student&nbsp;<strong>Huijuan Yang</strong>&nbsp;selected human counterparts of the eight immunomodulatory genes and used them to create the first FailSafe and cloaked human cells. Co-culturing these cells alongside human immune cells from an unmatched host revealed their ability to escape destruction, unlike their unmodified counterparts.</p> <p>This shows that cloaking has the potential to work for human patients as well, said Nagy.</p> <p>While the research is still at an early stage, it holds great promise for regenerative medicine and cell-based therapies. Nagy envisions injecting uncloaked insulin-producing cells, or islets, into subcutaneous cloaked tissue to treat diabetes. Subcutaneous cell delivery may be less risky for patients than the current approach, where islets are delivered into the liver and may interfere with its normal function, Nagy said.</p> <p>“This study gives invaluable insights into elegant alternatives to the toxic consequences of conventional immunosuppression,” said&nbsp;<strong>Michael Sefton</strong>, scientific director of&nbsp;<a href="https://mbd.utoronto.ca/">Medicine by Design</a>, a U of T&nbsp;<a href="https://isi.utoronto.ca/">institutional strategic initiative</a>&nbsp;focused on regenerative medicine that primarily funded the research, who is a <a href="https://www.provost.utoronto.ca/awards-funding/university-professors/">University Professor</a>&nbsp;in the department of chemical engineering and applied chemistry and the Institute of Biomedical Engineering in U of T’s Faculty of Applied Science &amp; Engineering.</p> <p>“These findings significantly advance cell therapies that can help people who live with chronic diseases such as type 1 diabetes or heart failure.”&nbsp;</p> <p>Beyond diabetes, Nagy is also developing applications for patients who have age-related macular degeneration, arthritis, chronic pain and lung diseases. To bring these advances to patients faster, he co-founded a startup company, panCELLa, which recently merged with the U.S. company Pluristyx to continue to develop safe and cost-effective clinical-grade, off-the-shelf&nbsp;cells for therapy.</p> <p>The research was funded by Medicine by Design, U of T, the Canadian Institutes for Health Research, Canada Research Chairs program and Ontario Research Fund.</p> <p>This story was&nbsp;<a href="https://www.sinaihealth.ca/news/scientists-create-cloaked-donor-cell-and-tissue-grafts-that-escape-rejection-by-the-immune-system/">originally published at <em>Sinai Health</em></a>.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Wed, 06 Dec 2023 16:16:29 +0000 Christopher.Sorensen 304768 at Researchers uncover molecular vulnerability in childhood brain cancer, identify treatment /news/researchers-uncover-molecular-vulnerability-childhood-brain-cancer-identify-treatment <span class="field field--name-title field--type-string field--label-hidden">Researchers uncover molecular vulnerability in childhood brain cancer, identify treatment </span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/medulloblastoma-crop.jpg?h=afdc3185&amp;itok=kmjraKwj 370w, /sites/default/files/styles/news_banner_740/public/medulloblastoma-crop.jpg?h=afdc3185&amp;itok=afKN7uXS 740w, /sites/default/files/styles/news_banner_1110/public/medulloblastoma-crop.jpg?h=afdc3185&amp;itok=7BLVGgGo 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/medulloblastoma-crop.jpg?h=afdc3185&amp;itok=kmjraKwj" alt="&quot;&quot;"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2023-01-12T10:04:24-05:00" title="Thursday, January 12, 2023 - 10:04" class="datetime">Thu, 01/12/2023 - 10:04</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">A brain scan of child with medulloblastoma tumour (Wikimedia Commons)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/donnelly-centre-cellular-biomolecular-research" hreflang="en">Donnelly Centre for Cellular &amp; Biomolecular Research</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>A team of researchers from the Ƶ’s Donnelly Centre for Cellular &amp; Biomolecular Research&nbsp;and McMaster University have made a potential breakthrough in medulloblastoma, a form of brain cancer that predominantly affects children and infants – a finding that could lead to new, targeted treatments that are less harmful to developing brains.</p> <p><strong>Rafael Montenegro-Burke</strong>, a senior co-author of the research and an assistant professor of molecular genetics in the&nbsp;Donnelly Centre for Cellular and Biomolecular Research&nbsp;at U of T’s Temerty Faculty of Medicine, says the current available treatment has been around for decades and consists of non-selective chemotherapy and radiation that destroy not only the cancer cells but also the healthy stem cells that are essential for brain development.&nbsp;</p> <p>“The damage that you do to the stem cells will have a huge impact on the brain development of these kids and cognitive function later in life,” he says. “The goal is to find a way to exclusively kill medulloblastoma and not harm the stem cells.”</p> <p>Working with Sheila Singh, a pediatric neurosurgeon and director of the&nbsp;Centre for Discovery in Cancer Research&nbsp;at McMaster University, the team was able to identify a molecule that is essential for the survival of medulloblastoma cells&nbsp;and target it with drugs to destroy cancer without touching the stem cells.</p> <p>The journal&nbsp;<em>Cancer Cell </em>recently&nbsp;<a href="https://www.cell.com/cancer-cell/pdfExtended/S1535-6108(22)00500-1">published the&nbsp;findings</a>.</p> <p><img class="migrated-asset" src="/sites/default/files/headshot%20collage.png" alt></p> <p><em>From left to right: U of T Assistant Professor&nbsp;Rafael Montenegro Burke, post-doctoral researcher William Gwynne and&nbsp;McMaster University’s&nbsp;Sheila Singh (photos supplied)</em></p> <p>The researchers took a relatively new approach of unbiased metabolomics to look for unique molecular signatures in the medulloblastoma cells that could be exploited for therapy. The field of metabolomics concerns the study of small molecules, or metabolites, that are produced by metabolic reactions in cells, or are taken up as nutrients from their surroundings. These include amino acids, sugars, lipids and other small molecules.</p> <p>Montenegro-Burke joined the Donnelly Centre in 2020 to establish one of the first metabolomics labs at the university. His group seeks to&nbsp;map metabolite diversity in healthy&nbsp;and diseased cells, and find out how metabolites contribute to disease, including cancer. He was recently named Canada Research Chair in functional metabolomics and lipidomics, a prestigious federal appointment reserved for top scholars in the country.</p> <p>Compared to genes and proteins, metabolite diversity and function remain largely unexplored, says Montenegro-Burke. Yet metabolic rewiring is a key mechanism that allows cancer cells to rapidly adapt to a changing environment. It was first reported a century ago by German scientist Otto Heinrich Warburg, who won the Nobel Prize for his work in 1931.</p> <p>“We’ve known for a long time that cancer affects metabolism,” says Montenegro-Burke. “The cancer needs all those nutrients not only to be able to grow, but also to adapt to survive treatment and the immune system.</p> <p>“Every time we look at these cancer cells and profile them, we see substantial metabolic differences.”&nbsp;</p> <p>The researchers focused on group 3 medulloblastoma, caused by an overabundance of the MYC protein that spurs cell proliferation. These tumours are “a particularly sinister subtype” as they often spread prior to diagnosis and recur, says William Gwynne, a former post-doctoral researcher in the Singh lab and first author on the paper.</p> <p>“Once the disease recurs, it is almost ostensibly incurable,” said Gwynne, who recently joined Montenegro-Burke’s lab to conduct more post-doctoral work.</p> <p>The team compared metabolite diversity between the cell lines derived from patient tumours and healthy stem cells. Using untargeted mass spectrometry, a method for detecting molecules based on their mass, they were able to detect tens of thousands of metabolites&nbsp;– the vast majority of which were unknown. They then applied computational biology approaches that allowed them to identify about 1,000 metabolites, reaching the limit of available technology.</p> <p>What immediately struck them was that high MYC levels correlated with availability of pyrimidine, a small molecule that is used to create a coating around the MYC protein that shields it from degradation.</p> <p>They reasoned that removing pyrimidine from medulloblastoma cells would lead to MYC destruction and halt cell proliferation&nbsp;–which&nbsp;is exactly what they observed. Depleting pyrimidine either by removing the enzyme responsible for its biosynthesis, or by inhibiting its function with drugs, triggered MYC degradation in cancer cells, leading them to undergo apoptosis, also known as “cellular suicide”.</p> <p>“This metabolite is absolutely necessary for MYC to be functional and to drive tumours,” says Montenegro-Burke. “We don’t yet fully understand its role, but we can start thinking about how to treat medulloblastoma.”</p> <p>Gwynne adds that the inhibitors of pyrimidine biosynthesis have a real potential as drug candidates&nbsp;due to their ability to kill cancer at low doses while sparing healthy stem cells.</p> <p>Similar compounds are already making their way through clinical trials for the treatment of several other cancers. Here the drugs are used to kill cancer cells by blocking DNA synthesis that also requires pyrimidine. The researchers hope&nbsp;the ongoing clinical studies pave the way for a medulloblastoma trial soon.</p> <p>If effective, other patient populations could also benefit, as MYC is a known driver of different types of leukemia and breast and lung cancer, says Gwynne.</p> <p>The study was funded by the Canadian Institutes of Health Research, the Ontario Institute for Cancer Research and donations from the Box Run Foundation and Team Kelsey Foundation.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Thu, 12 Jan 2023 15:04:24 +0000 Christopher.Sorensen 179030 at Researchers crack 30-year-old mystery of odour switching in worms /news/researchers-crack-30-year-old-mystery-odour-switching-worms <span class="field field--name-title field--type-string field--label-hidden">Researchers crack 30-year-old mystery of odour switching in worms</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/animal-5-stack--web-lead.jpg?h=afdc3185&amp;itok=GfBTScYT 370w, /sites/default/files/styles/news_banner_740/public/animal-5-stack--web-lead.jpg?h=afdc3185&amp;itok=sdsc0rGI 740w, /sites/default/files/styles/news_banner_1110/public/animal-5-stack--web-lead.jpg?h=afdc3185&amp;itok=wszi1FkE 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/animal-5-stack--web-lead.jpg?h=afdc3185&amp;itok=GfBTScYT" alt="&quot;&quot;"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2022-08-02T15:06:40-04:00" title="Tuesday, August 2, 2022 - 15:06" class="datetime">Tue, 08/02/2022 - 15:06</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">The head of an adult C. elegans worm, with the olfactory neuron expressing a particular type of odorant receptor shown in green (image by Daniel Merritt)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/donnelly-centre-cellular-biomolecular-research" hreflang="en">Donnelly Centre for Cellular &amp; Biomolecular Research</a></div> <div class="field__item"><a href="/news/tags/molecular-genetics" hreflang="en">Molecular Genetics</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Soil-dwelling nematodes&nbsp;depend on their sophisticated sense of smell for survival,&nbsp;able to distinguish between more than a thousand different scents –&nbsp;but the molecular mechanism behind their olfaction has baffled scientists for decades.&nbsp;</p> <p>Now, researchers at the Ƶ's&nbsp;Terrence Donnelly Centre for Cellular &amp; Biomolecular Research appear to have solved the long-standing mystery – and the implications of their findings stretch beyond nematode olfaction, perhaps offering insights into how the&nbsp;human brain&nbsp;functions.&nbsp;</p> <p><strong>Derek van der Kooy</strong>,&nbsp;a professor of molecular genetics at the Donnelly Centre in the Temerty Faculty of Medicine, led a research team that uncovered the molecular mechanism behind the worms' sense of smell, suggesting that it involves a conserved protein that helps equilibrate vision in humans.&nbsp;</p> <p>The van der Kooy lab is renowned for its neuroscience research that uses a variety of model organisms, including the nematode&nbsp;<em>Caenorhabditis elegans</em>.</p> <p><a href="https://www.pnas.org/doi/10.1073/pnas.2116957119">The researchers' study was published</a> in the <em>Proceedings of the National Academy of Sciences</em> (PNAS) last week.&nbsp;</p> <p>“The worms have an incredible sense of smell –&nbsp;it’s absolutely amazing,” says&nbsp;<strong>Daniel Merritt</strong>, a first co-author on the paper and recent&nbsp;PhD graduate who worked&nbsp;in the van der Kooy lab.</p> <p>“They can detect a very wide variety of compounds, such as molecules released from soil, fruit, flowers and&nbsp;bacteria. They can even smell explosives and cancer biomarkers in the urine of patients,” he adds.</p> <p><em>C. elegans</em>&nbsp;are champion sniffers thanks to their 1,300 odorant receptors. As in humans, who possess a mere 400 receptors, each receptor is dedicated to sensing one type of smell – but that's where the similarities end.</p> <p>Human noses are lined with hundreds of sensory neurons, each expressing only one receptor type. When an odorant activates a given neuron, the signal travels deeper into the brain along its long process, or axon, where it is perceived as smell. Smell discrimination is enabled by a physical separation of axonal cables carrying different smell signals.</p> <p>The worms, however, have only 32 olfactory neurons, which hold all of their 1,300 receptors.</p> <p>“Clearly, the one-neuron-one-smell strategy is not going to work here,” Merritt says.</p> <p>Yet, the worms can discriminate between different smells sensed by the same neuron. Pioneering research from the early 1990s showed that when exposed to two attractive odours, where one is uniformly present and the other is localized, the worms crawl towards the latter. But how this behaviour is regulated at the molecular level remained unclear.</p> <p>“It seems that all the information that is sensed by this neuron gets compressed into one signal, and yet the worm can somehow tell the difference between the upstream components. That’s where we came to it,” Merritt says.</p> <p>Merritt and former master’s of science graduate&nbsp;<strong>Isabel MacKay-Clackett</strong>, a co-first author on the paper, reasoned that perhaps the worms are sensing&nbsp;how strong&nbsp;the smells are.</p> <p>According to their hypothesis, the smells that are everywhere are not the most informative cues and would become desensitized in some way, meaning the worms would ignore them. This would leave the weakly present smells, which might be more useful in guiding behaviour, able to activate their receptors and cause signal transduction.</p> <p><iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen frameborder="0" height="422" src="https://www.youtube.com/embed/2RWyo1ooiPc" title="YouTube video player" width="760"></iframe></p> <p>They also had a hunch for how this could work at the molecular level. A protein named arrestin is a well-established desensitizer of the so-called G protein coupled receptors (GPCRs), a large family of proteins that perceive external stimuli, which odorant receptors belong to. Arrestins for example allow us to adjust vision in bright light by damping down signalling through the photon-sensing receptors in the retina.</p> <p>The team wondered if arrestin might also act in worms to desensitize receptors for a stronger smell in favour of those for a weaker one, when both are sensed by the same neuron. To test their hypothesis, they exposed the worms lacking the arrestin gene to two different attractive smells in a Petri dish. They mixed one smell into the agar medium to make it uniform, and put the worms on top. The other smell was placed at one spot some distance from the worms.</p> <p>Without arrestin, the worms were no longer able find the source of the weaker smell. Like in the human eye squinting in bright sunshine, arrestin helps remove an overpowering sensation – ambient smell in this case – so that the worms can sense a localized smell and move towards it, MacKay-Clackett says.</p> <p>Arrestin is not required, however, when the smells are sensed with different neurons, suggesting that the worms employ the same discrimination strategy as the vertebrates when the smell signals travel down different axons.</p> <p>The team looked at different sets of smells and neurons and found they all obeyed the same logic, Merritt says. They also used drugs to block arrestin and found that this too abolished smell discrimination.</p> <p>The finding is significant because it is the first evidence showing that arrestin can fine tune multiple sensations.</p> <p>“There is no case known in biology before this where arrestin is being used to allow for discrimination of signals external to the cell,” Merritt says.</p> <p>He adds that the same mechanism could be playing out in other animals when multiple GPCRs are expressed on the same cell, especially in the brain. Our brains are bathed in neurochemicals that signal through hundreds of different GPCRs, raising a possibility that arrestin, of which there are four types in humans, could be key for information processing.</p> <p>“Our work provides one piece of puzzle how the worms’ amazing sense of smell works, but it also informs our understanding of how GPCR signalling works more broadly within animals,” Merritt says.</p> <p>The team's research was supported by the Canadian Institutes of Health Research and the Natural Sciences and Engineering Research Council of Canada.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Tue, 02 Aug 2022 19:06:40 +0000 Christopher.Sorensen 175848 at Researchers use rapid antibody test to gauge immune response to SARS-CoV-2 variants /news/researchers-use-rapid-antibody-test-gauge-immune-response-sars-cov-2-variants <span class="field field--name-title field--type-string field--label-hidden">Researchers use rapid antibody test to gauge immune response to SARS-CoV-2 variants</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/GettyImages-1231902723-crop.jpg?h=afdc3185&amp;itok=qCtCLJS8 370w, /sites/default/files/styles/news_banner_740/public/GettyImages-1231902723-crop.jpg?h=afdc3185&amp;itok=LY3FrOho 740w, /sites/default/files/styles/news_banner_1110/public/GettyImages-1231902723-crop.jpg?h=afdc3185&amp;itok=XmKMay4- 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/GettyImages-1231902723-crop.jpg?h=afdc3185&amp;itok=qCtCLJS8" alt="a woman walks past a Toronto COVID-19 assessment centre"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2022-07-06T09:17:59-04:00" title="Wednesday, July 6, 2022 - 09:17" class="datetime">Wed, 07/06/2022 - 09:17</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">A U of T study found the antibodies generated by people who were vaccinated and/or recovered from COVID-19 prior to 2022 failed to neutralize today's variants (photo by Shawn Goldberg/SOPA Images/LightRocket via Getty Images)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/covid-19" hreflang="en">COVID-19</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/donnelly-centre-cellular-biomolecular-research" hreflang="en">Donnelly Centre for Cellular &amp; Biomolecular Research</a></div> <div class="field__item"><a href="/news/tags/biochemistry" hreflang="en">Biochemistry</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>COVID-19 infections are once again on the rise as our immune systems struggle to combat new variants.&nbsp;</p> <p>That’s according to a Ƶ study that found&nbsp;the antibodies generated by people who were vaccinated and/or recovered from COVID-19&nbsp;prior to 2022 failed to neutralize the variants circulating today.</p> <p><img alt="Igor Stagljar" src="/sites/default/files/Igor_Tonko%20Buterin.png" style="width: 250px; height: 303px; margin-left: 10px; margin-right: 10px; float: left;"></p> <p>Furthermore, the researchers expect that the antibody test they developed to measure immunity in the study’s participants will become a valuable tool for deciding who needs a booster and when,&nbsp;helping to save lives and avoid future lockdowns.</p> <p>“The truth is we don’t yet know how frequent our shots should be to prevent infection,” said&nbsp;<strong>Igor Stagljar</strong>, a professor of biochemistry and molecular genetics&nbsp;at the&nbsp;Donnelly Centre for Cellular and Biomolecular Research and&nbsp;at the Temerty Faculty of Medicine. “To answer these questions, we need rapid, inexpensive and quantitative tests that specifically measure Sars-CoV-2 neutralizing antibodies, which are the ones that prevent infection.”</p> <p>The study was led by<strong>&nbsp;</strong>Stagljar&nbsp;and <strong>Shawn Owen</strong>, an associate professor of pharmaceutics and pharmaceutical chemistry, at the University of Utah.</p> <p>The journal&nbsp;<em>Nature Communications </em>recently<em>&nbsp;</em><a href="https://www.nature.com/articles/s41467-022-31300-9">published their findings</a>.</p> <p>Many antibody tests have been developed over the past two years. But only a few of the authorized ones are designed to monitor neutralizing antibodies, which coat the viral spike protein so that it can no longer bind its receptor and enter cells.</p> <p>It's an important distinction, as only a fraction of all Sars-CoV-2 antibodies generated during infection are neutralizing. And while most vaccines were specifically designed to produce neutralizing antibodies, it’s not clear how much protection they give against variants.</p> <p>“Our method, which we named Neu-SATiN, is as accurate as&nbsp;– but faster and cheaper than&nbsp;– the gold standard, and it can be quickly adapted for new variants as they emerge,” Stagljar said.</p> <p>Neu-SATiN stands for&nbsp;Neutralization&nbsp;Serological&nbsp;Assay based on split&nbsp;Tri-part&nbsp;Nanoluciferase, and it is a newer version of&nbsp;SATiN, which monitors the complete IgG pool&nbsp;they developed last year.</p> <p>The development of Neu-SATiN was spearheaded by&nbsp;<strong>Zhong Yao</strong>, a senior research associate in Stagljar’s lab, and <strong>Sun Jin Kim</strong>, a post-doctoral researcher&nbsp;in Owen’s lab, who are the co-first authors on the paper.</p> <p>The pinprick test is powered by the fluorescent luciferase protein from a deepwater shrimp. It measures the binding between the viral spike protein and its human ACE2 receptor, each of which is attached to a luciferase fragment. The engagement of the spike protein with ACE2 pulls the fragments close, catalyzing reconstitution of the full length luciferase&nbsp;with a concomitant glow of light captured by the luminometer instrument. When a patient’s blood sample is added into the mixture, the neutralizing antibodies bind to&nbsp;– and mop up – all spike protein, while ACE2 remains in unengaged state. Consequentially, the luciferase remains in pieces&nbsp;and the light signal drops. The researchers say the plug-and-play design of the test means it can be adapted to emerging variants by engineering mutations in the spike protein.</p> <p>The researchers applied Neu-SATiN to blood samples collected from 63 patients with different histories of COVID-19 and vaccination&nbsp;up to November 2021. Patient neutralizing capacity was assessed against the original Wuhan strain&nbsp;and the following variants:&nbsp;Alpha, Beta, Gamma, Delta and Omicron.</p> <p>“We thought it would be important to monitor people that have been vaccinated to see if they still have protection and how long it lasts,” said Owen, who did his post-doctoral training in the Donnelly Centre with distinguished bioengineer and <a href="https://www.provost.utoronto.ca/awards-funding/university-professors/">University Professor</a> <strong>Molly Shoichet </strong>of the Faculty of Applied Science &amp; Engineering.&nbsp;“But we also wanted to see if you were vaccinated against one variant, does it protect you against another variant?”</p> <p>The neutralizing antibodies were found to last about three to four months before&nbsp;their levels would drop by about 70 per cent irrespective of infection or vaccination status. Hybrid immunity, acquired through both infection and vaccination, produced higher antibody levels at first, but these too dropped significantly four months later.</p> <p>Most worryingly, infection and/or vaccination provided good protection against the previous variants, but not Omicron&nbsp;or its sub-variants&nbsp;BA.4 and BA.5.</p> <p>The data match those from <a href="https://www.theguardian.com/world/2022/jun/14/people-who-caught-covid-in-first-wave-get-no-immune-boost-from-omicron">a&nbsp;recent U.K. study</a> that&nbsp;showed that both neutralizing antibodies and cellular immunity&nbsp;– a type of immunity provided by memory T cells&nbsp;–&nbsp;from either infection, vaccination, or both, offered no protection from catching Omicron. In a surprising twist, the U.K. group also found that infections with Omicron boosted immunity against earlier strains, but not against Omicron itself&nbsp;for reasons that remain unclear.</p> <p>“It's important to stress that vaccines still confer significant protection from severe disease and death,” said Stagljar. Still, he added that the findings from his team and others call for vigilance in the coming period&nbsp;given that the more transmissible BA.4 and BA.5 sub-variants can escape immunity acquired from earlier infections with Omicron, as attested by rising reinfections.</p> <p>“There will be new variants in the near future for sure,” Stagljar said. “Monitoring and boosting immunity with respect to circulating variants will become increasingly important and our method could play a key role in this since it is fast, accurate, quantitative and cheap.”</p> <p>He is already collaborating with the Canadian vaccine maker Medicago to help determine the efficacy of their candidates against Omicron and its sub-variants.&nbsp;Meanwhile, U of T is negotiating to license Neu-SATiN to a company which will scale it up for real world uses&nbsp;such as population immunosurveillance and vaccine development.</p> <p>The research was supported with funding from the <a href="/news/u-t-support-31-high-impact-coronavirus-research-projects-through-toronto-covid-19-action-fund">Toronto COVID-19 Action Fund</a>,&nbsp;Division of the Vice-President, Research &amp; Innovation and the 3i Initiative at the University of Utah.</p> <h3><a href="https://www.thestar.com/news/canada/2022/07/10/if-you-got-covid-early-this-year-you-can-get-reinfected-now-u-of-t-study-finds.html?utm_source=share-bar&amp;utm_medium=user&amp;utm_campaign=user-share">Read more about the research in the <em>Toronto Star</em></a></h3> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Wed, 06 Jul 2022 13:17:59 +0000 Christopher.Sorensen 175500 at RNA map of cell nucleus reveals new insights into gene regulation and cell division /news/rna-map-cell-nucleus-reveals-new-insights-gene-regulation-and-cell-division <span class="field field--name-title field--type-string field--label-hidden">RNA map of cell nucleus reveals new insights into gene regulation and cell division</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/nuclear-speckles-crop.jpg?h=afdc3185&amp;itok=k1SwKlK6 370w, /sites/default/files/styles/news_banner_740/public/nuclear-speckles-crop.jpg?h=afdc3185&amp;itok=ZIpFsbTe 740w, /sites/default/files/styles/news_banner_1110/public/nuclear-speckles-crop.jpg?h=afdc3185&amp;itok=DTad9NLW 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/nuclear-speckles-crop.jpg?h=afdc3185&amp;itok=k1SwKlK6" alt="&quot;&quot;"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2022-03-18T11:17:55-04:00" title="Friday, March 18, 2022 - 11:17" class="datetime">Fri, 03/18/2022 - 11:17</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">Microscopy images of cell nuclei with labeled RNA transcripts that contain retained introns (Image courtesy of Barutcu, Wu et al. in Molecular Cell).</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/jovana-drinjakovic" hreflang="en">Jovana Drinjakovic</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/sinai-health" hreflang="en">Sinai Health</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/donnelly-centre-cellular-biomolecular-research" hreflang="en">Donnelly Centre for Cellular &amp; Biomolecular Research</a></div> <div class="field__item"><a href="/news/tags/lunenfeld-tanenbaum-research-institute" hreflang="en">Lunenfeld-Tanenbaum Research Institute</a></div> <div class="field__item"><a href="/news/tags/hospital-sick-children" hreflang="en">Hospital for Sick Children</a></div> <div class="field__item"><a href="/news/tags/molecular-genetics" hreflang="en">Molecular Genetics</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Most people are familiar with the cell nucleus from grade school biology as a storage compartment for DNA. But the nucleus also contains several distinct structures&nbsp;called nuclear bodies or domains – and some of them are brimming with genes’ messages, also known as RNA transcripts.</p> <p>Scientists are just now beginning to understand these structures, with Ƶ researchers recently reporting&nbsp;the first large-scale survey of RNA transcripts that are associated with different nuclear bodies in human cells.</p> <p>The work, <a href="https://www.cell.com/molecular-cell/pdf/S1097-2765(21)01072-8.pdf">published in the journal&nbsp;<em>Molecular Cell</em></a>, suggests that the structures act as hubs to co-ordinate gene regulation and cell division.</p> <p>“It was known that some nuclear domains contain RNA, but the composition of that RNA was not systematically probed in previous studies,” said&nbsp;<strong>Benjamin Blencowe</strong>, senior author on the study and a professor of molecular genetics in the Donnelly Centre for Cellular and Biomolecular Research&nbsp;at the Temerty Faculty of Medicine.</p> <p>“Our data has shed light not only on the RNA composition of different nuclear domains, but also provides clues as to the functions of some of these domains.”&nbsp;</p> <p>Until now, the information on nuclear body composition has trickled in piecemeal because there were no methods enabling a systematic survey of RNA localized to these structures. But post-doctoral researcher <strong>Rasim Barutcu</strong>&nbsp;and graduate student&nbsp;<strong>Mingkun Wu</strong>&nbsp;realized they could apply a method called APEX-Seq, which had been developed by scientists at Stanford University and the University of California, Berkeley.</p> <p>APEX is an enzyme that can be fused to any protein of interest and allows labeling of RNAs&nbsp;and other biomolecules&nbsp;in its proximity. The labeled RNAs can then be isolated and identified by sequencing. By fusing APEX to various marker proteins residing in the different nuclear bodies, Barutcu and Wu were able to create RNA maps for each.</p> <p>The pair collaborated with&nbsp;<strong>Ulrich Braunschweig</strong>, a senior research associate in Blencowe’s lab, and with the groups of:&nbsp;<strong>Anne-Claude Gingras</strong>, a senior scientist at the Lunenfeld-Tanenbaum Research Institute,&nbsp;Sinai Health System, and professor of molecular genetics;&nbsp;<strong>Philipp Maass</strong>, a scientist at The&nbsp;Hospital for Sick Children and&nbsp;assistant professor of molecular genetics;&nbsp;and&nbsp;Robert Weatheritt,&nbsp;a principal investigator at the&nbsp;Garvan Institute of Medical Research in&nbsp;Australia.</p> <p>The team discovered swaths of novel RNAs&nbsp;– from several hundred to thousands&nbsp;– across the nuclear bodies. Previously, only a handful of transcripts were known to be associated with some of these structures, said Barutcu, whose research was supported by the Banting Postdoctoral Fellowship and a fellowship from the Canadian Institutes of Health Research (CIHR).</p> <p>One piece of data immediately struck the researchers: The nuclear bodies known as speckles were associated with surprisingly high numbers of RNA transcripts with retained introns&nbsp;– segments that do not code for proteins. When a gene is transcribed into RNA, introns must be spliced out in the nucleus before the transcript can be released into the cell’s interior to serve as a template for making proteins.</p> <p>The finding led them to realize that speckles are associated with a class of introns with delayed splicing. The nature of the transcripts provided a clue to their function. They were transcribed from genes that control various aspects of gene regulation and the cell division cycle. Genes controlling cell cycle progression must be activated in a timely manner so that their protein products are made only when they are needed. Errors in this process are well known drivers of cancer.</p> <p>The researchers came up with a model in which the role of the speckles might be to co-ordinate intron removal from transcripts in order to regulate their release from the nucleus, and their subsequent translation into protein factors required for gene regulation and the cell cycle. This mechanism would help ensure a rapid response to cellular signals to make the right kinds of proteins at the right time.</p> <p>Furthermore, when speckles were disrupted, this altered the splicing of the retained introns, including those located in genes that are directly involved in control of the cell cycle, supporting the idea that the speckles are linked to cell cycle progression.</p> <p>The model opens up new ways of thinking about cell cycle regulation with implications for cancer research, said Blencowe, who holds a Canada Research Chair in RNA Biology and Genomics and Banbury Chair in Medical Research.</p> <p>“We’ve uncovered a mechanism involving differential intron retention linked to speckle integrity that could play an important role in not just normal cell division but also how it goes wrong in cancers,” he said, noting that the project was made possible by the now defunct CIHR Foundation grant scheme, which provided long-term research funding.</p> <p>In addition to the speckles, the team also found large numbers of intron-retained transcripts associated with the nuclear lamina, which forms at the periphery of the nucleus. However,&nbsp;the functional significance of this observation remains unclear.</p> <p>The researchers said they hope others in the field will take advantage of their datasets and open new avenues of research into nuclear body function where many questions remain.</p> <p>&nbsp;</p> <p>&nbsp;</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Fri, 18 Mar 2022 15:17:55 +0000 Christopher.Sorensen 173573 at