Three UHN researchers were elected as Fellows of the Canadian Academy of Health Sciences (CAHS). As one of the highest honours in Canadian health sciences, Fellows are nominated from all disciplines and recognized for their excellence in advancing academic health sciences.
Congratulations to the following UHN researchers, who were among the 47 newly elected Fellows:
● Dr. Laura Dawson is a Clinician Investigator at UHN’s Princess Margaret Cancer Centre. Her research focuses on implementing advanced radiation technologies and exploring innovative therapeutic combinations to improve outcomes and minimize the side effects of radiation therapy, with a particular emphasis on liver cancers.
● Dr. Natasha Leighl is the Division Head of Medical Oncology and Hematology and a Clinician Investigator at UHN’s Princess Margaret Cancer Centre. Her primary area of research is the development of novel treatments for lung cancer, including targeted and immune-based therapies, and incorporating novel diagnostics such as liquid biopsy into patient care.
● Dr. Milica Radisic is a Senior Scientist at UHN. Her research explores cardiac tissue engineering and regenerative medicine, focusing on developing new biological materials and lab-grown heart tissue to treat heart failure and improve recovery after heart attacks.
For a full list of the 2025 CAHS Fellows, read the press release here.
Tell us about your role at UHN.
I am a PhD student working in the lab of Dr. Sara Vasconcelos and a part of the combined MD/PhD program at the University of Toronto.
How long have you been in this role?
Since September 2023.
What are you passionate about in your role at UHN? What does health research mean to you?
I am excited to be advancing our understanding and development of vascularization technologies for regenerative medicine. Health research is a collaborative effort to achieve better outcomes and therapies for all patients. It is inspiring to be at a collaborative institute such as UHN, which draws expertise from all areas of health care and STEM (science, technology, engineering, and math).
What are you working on at UHN? How does your work help to advance UHN's vision of A Healthier World?
Approximately 70,000 Canadians have a heart attack each year. Triggered by a blockage in the vessels that feed the heart, a heart attack causes irreversible damage and reduces the heart’s ability to pump blood to the rest of the body. Recently, stem cells, which are cells that can multiply and develop into any cell type in the body, have emerged as a promising approach to generate new heart cells. Scientists have found a way to inject these stem cells into the heart to replace damaged tissue. However, this method has not yet succeeded in the clinic because of problems with cell survival caused by a lack of nutrient and oxygen delivery.
Our lab is studying a novel approach that transplants tiny blood vessels, called microvessels, harvested from fat tissue alongside stem cells into damaged hearts to help generate new heart cells. This technique has demonstrated success in restoring blood supply and improving stem cell survival in pre-clinical models. It is currently the only method that has shown long-term success in maintaining stem cell survival. However, to use microvessels in combination with stem cell therapies in humans, they must first be tested in non-human models to understand how they support stem cells.
My project focuses on evaluating whether microvessels are safe and effective in a model known to closely resemble human physiology. Using advanced imaging technologies, I am also studying how these microvessels develop and identifying the key factors needed for their maturation. In doing so, my work supports the translation of microvessel strategies into the clinic and helps establish a strong framework for ensuring their reliability in stem cell therapies. This research has the potential to improve heart attack treatment and the lives of thousands of patients.
What makes UHN an ideal place to advance health research?
No matter where you work at UHN—whether at the patient’s bedside, the lab bench, or in another setting—we all share one common goal: to improve patient lives and the future of health care. This is evident in every UHN building you walk into. It is an exciting and stimulating place to work because of this shared energy.
Do you have any interests outside of work?
Outside of the lab, I enjoy running, baking, and exploring the Toronto food scene. I am also a former synchronized swimmer, having swum for 15 years. I remain active in the synchronized swimming community through coaching and advocacy work.
What do you see for the future of health research, and what gets you excited about it?
As someone on a training path that combines patient care and research, I am excited about the opportunity to bridge these two areas. The future of health research is moving toward a model in which clinical insight and scientific inquiry are closely connected, and in which non-traditional fields work together to address complex scientific questions. I look forward to a career where I can see how these fields change as science advances and contribute to them in a meaningful way.
You @TeamUHN is a campaign to highlight the important scientific contributions that research lab staff, trainees and learners, administrative staff, core facilities staff, Research Solutions & Services staff, and volunteers make towards A Healthier World through discovery and innovation. If you’re interested in sharing your story, we invite you to complete this form here (Open to UHN staff, trainees and volunteers).
Researchers at UHN are part of a team evaluating a potential new therapy for people with long-standing and hard-to-manage type 1 diabetes (T1D) who experience frequent, severe low blood sugar events. Results from an early-stage clinical trial, recently published in the New England Journal of Medicine, show promise for an approach to restore insulin production using stem cell–derived islets—clusters of cells in the pancreas that produce and secrete hormones.
More than 8 million people worldwide live with T1D, where the body's immune system destroys insulin-producing cells in the pancreas. Managing T1D remains difficult due to specific insulin therapy and glucose monitoring requirements. Even with the best tools, the disease can lead to serious long-term health complications.
A multi-site trial that includes UHN as one of the clinical sites has investigated a new therapy called zimislecel, which uses lab-grown insulin-producing islets derived from pluripotent stem cells—cells that can develop into any tissue type. These cells are infused into the liver through the portal vein, a blood vessel that carries blood from organs in the abdomen to the liver. Participants also received immunosuppressive medications to help prevent rejection of the transplanted cells.
Dr. Trevor Reichman, Surgical Director of the Pancreas and Islet Transplant Program at UHN’s Ajmera Transplant Centre and Clinician Investigator UHN, is the study’s lead Canadian author.
The study included 14 adults with longstanding T1D who had impaired ability to perceive the onset of hypoglycemia and recurrent severe hypoglycemia. Hypoglycemia occurs when blood sugar drops too low and can cause symptoms such as confusion, dizziness, seizures, or loss of consciousness. Severe cases require help from another person and can be life-threatening.
Before treatment, none of the participants produced measurable insulin on their own. One year after a single infusion of zimislecel, all participants who received the full dose experienced improved blood sugar control and no severe hypoglycemic events. Ten of these participants (83%) were insulin-independent at the one-year mark. Most reported side effects were mild or moderate and consistent with those seen in transplant recipients.
While these results are early and based on a small group, they suggest that stem cell–derived islets may help restore natural insulin production and improve safety for people with high-risk T1D. Ongoing studies will provide more insight into the long-term effectiveness, safety, and accessibility of this approach. The study is now in Phase 3, which will take the total participant number to 50.
UHN continues to play a key role in research that supports the safe and evidence-based advancement of new therapies for diabetes and other chronic diseases.
Dr. Trevor Reichman, Clinician Investigator at UHN and Associate Professor in the Department of Surgery at the University of Toronto, is the first author of this study that includes investigators in the VX-880-101 (zimislecel) FORWARD Study Group.
This study was funded by Vertex Pharmaceuticals and supported by UHN Foundation.
Reichman TW, Markmann JF, Odorico J, Witkowski P, Fung JJ, Wijkstrom M, Kandeel F, de Koning EJP, Peters AL, Mathieu C, Kean LS, Bruinsma BG, Wang C, Mascia M, Sanna B, Marigowda G, Pagliuca F, Melton D, Ricordi C, Rickels MR; VX-880-101 FORWARD Study Group. Stem Cell-Derived, Fully Differentiated Islets for Type 1 Diabetes. N Engl J Med. 2025 Jun 20. doi: 10.1056/NEJMoa2506549. Epub ahead of print. PMID: 40544428.
In neurodegenerative diseases (ND), such as Alzheimer disease or Amyotrophic Lateral Sclerosis (ALS), early diagnosis is critical for the most effective—or disease-modifying—treatments. Neuroinflammation, which is defined by increased levels of inflammation-causing proteins in the brain, is a key feature of these conditions.
Previous studies suggest neuroinflammation can be detected before other brain changes that are typically used to diagnose NDs appear. This means it could be a marker for earlier diagnosis. Unfortunately, many current diagnostic tools cannot detect signs of neuroinflammation—or they require invasive procedures.
A recent study from UHN’s Krembil Brain Institute (KBI) suggests free-water diffusion (FWD) MRI could fill this diagnostic gap. Free water is water in the brain that is not contained inside brain cells. FWD MRI measures how much of this water is present and how it moves. Changes in its amount, location, or movement can signal processes like neuroinflammation and cell death.
The KBI team analyzed MRI data and blood samples from 367 patients with various NDs collected through the Ontario Neurodegenerative Research Initiative (ONDRI) database. They assessed FWD patterns in brain scans and measured blood levels of two protein markers—GFAP (linked to neuroinflammation) and NfL (linked to cell damage).
Using machine learning, the researchers found that specific FWD patterns could predict GFAP levels, suggesting the technique may detect neuroinflammation. They also identified differences in FWD patterns between different NDs—hinting that FWD MRI could be used to help identify not only the presence of neuroinflammation but also the type of ND in its early stages.
“Further studies in larger and more diverse groups are needed to confirm reliability and effectiveness,” says the study’s senior author and a Krembil Clinician Investigator, Dr. Carmela Tartaglia. “But we believe FWD MRI has great potential as a diagnostic tool.”
As a non-invasive technique that uses existing technologies, FWD MRI offers a way to make ND diagnosis at an earlier stage easier and more widely available. For more patients, this could mean a better chance at effective management of and a life less impacted by neurodegeneration.
The first author of this study is Vishaal Sumra, a PhD candidate at the University of Toronto’s Institute of Medical Science.
The senior author is Dr. Carmela Tartaglia, a Clinician Investigator at UHN’s Krembil Brain Institute and a professor at the University of Toronto’s Tanz Centre for Neurodegenerative Diseases.
This work was supported by UHN Foundation. The ONDRI study was supported by the Ontario Brain Institute (OBI).
The authors report no competing interests for this work. For a full list of financial and personal interests, see the publication.
Sumra V, Hadian M, Dilliott AA, Farhan SMK, Frank AR, Lang AE, Roberts AC, Troyer A, Arnott SR, Marras C, Tang-Wai DF, Finger E, Rogaeva E, Orange JB, Ramirez J, Zinman L, Binns M, Borrie M, Freedman M, Ozzoude M, Bartha R, Swartz RH, Munoz D, Masellis M, Black SE, Dixon RA, Dowlatshahi D, Grimes D, Hassan A, Hegele RA, Kumar S, Pasternak S, Pollock B, Rajji T, Sahlas D, Saposnik G, Tartaglia MC; ONDRI Investigators. Regional free-water diffusion is more strongly related to neuroinflammation than neurodegeneration. J Neurol. 2025 Jun 25;272(7):478. doi: 10.1007/s00415-025-13201-1.
Three UHN research teams have received a total of $1.2 million through the 2025 Canadian Cancer Society-UHN Research Grants on Neurofibromatosis and Cancer: Probing the Links. This grant was enabled through the generosity of the Elisabeth Raab Foundation.
This joint funding initiative—supported by the Canadian Cancer Society, UHN, and the Toronto Elisabeth Raab Accelerator of Science to End Neurofibromatosis (To-ERASEnf)—aims to advance the understanding and treatment of neurofibromatosis type 1 (NF1), a genetic disorder associated with an increased risk of cancer. The program fosters collaboration between cancer researchers and experts in NF1 and related fields to uncover the genomic and molecular drivers of cancer in NF1. This research is part of a growing field of investigation into the relationship between cancer and the nervous system.
The following three projects received funding:
Project Title: Understanding and improving health care for people with NF1
Lead Investigator: Dr. Carolina Barnett-Tapia, Clinician Scientist at UHN
Dr. Barnett-Tapia and her research team are examining cancer development patterns in individuals with NF1. Using data from a registry of over 2,000 patients with NF1, the research team will assess screening practices, cancer types, and patient outcomes. The findings will help inform testing guidelines to support early detection and improve care delivery.
Project Title: Finding new ways to treat nerve tumours
Lead Investigators: Dr. Dalia Barsyte-Lovejoy, Affiliate Scientist at UHN’s Princess Margaret Cancer Centre (PM), and Dr. Suganth Suppiah, Clinician Scientist at PM.
This project investigates why some nerve tumours in people with NF1 become cancerous. By studying and altering tumour cell pathways in the lab, the team will shed light on how these cancers develop and test new treatments that could prevent or stop tumour progression.
Project Title: Testing tumour immunotherapy in models of neurofibromatosis type 1
Lead Investigator: Dr. David Kirsch, Senior Scientist at PM.
Dr. Kirsch is exploring whether immunotherapy—a type of treatment that helps the immune system fight cancer—can be effective for people with NF1 who develop aggressive soft tissue tumours. Using experimental models, the research team will test immunotherapy alone and in combination with radiation to identify safer and more effective treatment options.
Congratulations to the awardees. Read more on the grants here.
Air pollution, generated from sources such as burning fossil fuels and wildfire smoke, is a leading environmental health threat worldwide. In a new study from UHN, researchers found that long-term exposure to air pollution is associated with myocardial fibrosis—scarring of heart muscle that can lead to poor outcomes for cardiovascular disease.
The majority of the global population lives in areas with air pollution levels exceeding World Health Organization air quality limits. Fine particulate matter with a 2.5-μm or smaller diameter (PM2.5) is the most thoroughly studied component of air pollution. These tiny airborne particles can be inhaled deep into the lungs and are associated with an increased risk of cardiovascular diseases such as heart attack and stroke. However, exactly how PM2.5 affects the heart’s structure and function remains unclear.
A team led by Dr. Kate Hanneman used cardiac MRI to non-invasively measure fibrosis in the heart muscle and determine its relationship to long-term exposure to PM2.5. They analyzed cardiac MRI scans from 694 patients, including 493 with dilated cardiomyopathy—a condition where the heart becomes enlarged and weakened—and 201 with healthy hearts.
The team measured diffuse myocardial fibrosis—when scar tissue abnormally accumulates throughout the heart muscle—using a specialized MRI technique called T1 mapping. They also calculated each person’s average daily PM2.5 exposure in the year preceding MRI imaging, based on air quality measurements near their homes.
Results showed a clear trend: for every small increase in PM2.5 levels, both patients with heart disease and healthy individuals had more heart muscle scarring. The effect was strongest in women, smokers, and people with high blood pressure.
These findings suggest that long-term air pollution exposure could damage heart tissue, potentially increasing the risk of future heart problems. With wildfires becoming more frequent, these results highlight the need for public health measures to reduce air pollution and for individuals to limit exposure whenever possible.
Dr. Jacques Du Plessis, who was a clinical cardiovascular imaging fellow at the University of Toronto, is the first author of the study.
Dr. Kate Hanneman, Clinician Scientist at UHN and Associate Professor in the Department of Medical Imaging at the University of Toronto, is the corresponding author of the study.
This work was supported by UHN Foundation.
Dr. Kate Hanneman has received payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from Sanofi, and is an associate editor for Radiology and Radiology: Cardiothoracic Imaging. For a full list of competing interests, see the manuscript.
Du Plessis J, DesRoche C, Delaney S, Nethery RC, Hong R, Thavendiranathan P, Ross H, Castillo F, Hanneman K. Association between Long-term Exposure to Ambient Air Pollution and Myocardial Fibrosis Assessed with Cardiac MRI. Radiology. 2025 Jul;316(1):e250331. doi: 10.1148/radiol.250331.
Welcome to the latest issue of Research Spotlight.
As Canada’s largest research hospital, UHN is a national and international source for discovery, education, and patient care. This newsletter highlights top research advancements from over 5,000 members of TeamUHN—a diverse group of trainees, staff, and principal investigators who conduct research at UHN.
Stories in this month’s issue:
● Cell Lineage Linked to Leukemia Type: Study explores human blood cell development and why certain blood cancers can switch lineages.
● Precision Diagnosis for Liver Grafts: New AI tool helps identify liver graft injuries early, enabling faster treatment decisions.
● Better Recovery Starts in the Mind: Three studies examine how targeting mental health and cognition may improve surgical outcomes.
● Adapting Care for Complex Needs: Assessing the need for more flexible care systems to better support complex recovery.
Read these stories and more online here. To read previous issues, see the newsletter archive.
Research conducted at UHN's research institutes spans the full spectrum of diseases and disciplines, including cancer, cardiovascular sciences, transplantation, neural and sensory sciences, musculoskeletal health, rehabilitation sciences, and community and population health.
Learn more about our institutes by clicking below:
