FEatured Lab of the CSATVB
JUNE 2026
Dr. Jason Fish
Title and Institutional Affiliation:
1. Senior Scientist, Peter Munk Cardiac Centre, UHN Research Institutes, University Health Network
2. Professor, Department of Laboratory Medicine & Pathobiology, University of Toronto
Where did you do your training?
I completed my PhD at the University of Toronto under the supervision of Dr. Philip Marsden, where I uncovered a role for epigenetics in gene regulation in blood vessels. This was followed by a postdoctoral fellowship at the Gladstone Institute of Cardiovascular Disease and the University of California San Francisco under the supervision of Dr. Deepak Srivastava. Here, I uncovered a role for microRNAs in regulating the development of the cardiovascular system. I returned to Toronto in 2010.
Describe your primary research focus: The Fish Lab investigates the molecular mechanisms that govern endothelial cell biology across a spectrum of vascular and cardiometabolic diseases. We discovered that somatic KRAS mutations within the endothelium are the primary cause of sporadic brain arteriovenous malformations (bAVMs). Building on this finding, we developed preclinical models of bAVM and leverage human patient-derived samples, including organoid systems and high-throughput screening platforms, to identify and test novel therapeutic strategies. Our research also examines how systemic inflammation and endothelial activation may create a susceptibility to cardiac damage during chemotherapy. We study how tumours influence the cardiac vasculature, how endothelial cells respond to chemotherapeutic agents, and how they communicate with cardiomyocytes through extracellular vesicles. In other projects in the lab, we investigate how diabetes alters cardiac microvascular function and how heart failure affects the brain, with the goal of defining vascular mechanisms that link multi-organ disease. Together with Dr. Kathryn Howe, we are also studying how the endothelial cell identity transcription factor, ERG, controls endothelial-to-mesenchymal transition in the setting of atherosclerosis.
List most recent or most impactful publications (max 3):
1. Wu R, Khosraviani K, Mansur A, Boudreau E,Largoza GE, Park S, Gustafson D, Raju S, Ching C, Klip A, Walchli T, Howe KL,Radovanovic I, Wythe JD, Fish JE. KRAS-dependent glycolytic reprogramming of endothelial cells in sporadic arteriovenous malformations. EMBO Molecular Medicine. 2026 Mar; 18(3):1091-1126. 10.1038/s44321-026-00383-y
2. *Gustafson D, *Mistry P, Ching C, Nardi-AgmonI, Yu C, Fan CP, Houbois C, Amir E, Marwick T, Abdel-Qadir H, McIntosh C, #Thavendiranathan P, #Fish JE. Pre-treatment circulating vascular biomarkers predict cancer therapy-related cardiac dysfunction during HER2+ breast cancer treatment. JACC:Cardio Oncology. 2025 Dec;7(7):870-885. *Co-first author; #Co-correspondingauthor. 10.1016/j.jaccao.2025.09.004
3. *Schulz K, *Botts SR, *Ellis K, Scipioine CA,Khyzha N, Ho C, Kumaragurubaran R, Yuki KE, Wythe JD, Miller CL, Wilson MD, #HoweKL, #Fish JE. ERG is a regulator of dynamic and reversible endothelial plasticity. Genome Medicine. 2026 May 1;18(1):53. 10.1186/s13073-026-01638-6. *Co-first author. #Co-correspondingauthor.
Favourite place to visit in Canada (and why): Canada is full of spectacular places to visit. Some of the favourite places that we have visited as a family include ‘glamping’ in a yurt in Bic National Park in Quebec and taking the ferry to Grand Manan Island in New Brunswick. These are such peaceful places, surrounded by amazing natural beauty. They are great places to recharge.
What would you have become if not a scientist? I don’t think I ever seriously contemplated a different career path. Over the past decade, I have done a lot of renovation work on my house. I really enjoy this type of work, even though it takes me 10 times longer than it would take an expert. There is a certain satisfaction from building something. Constructing a scientific paper is a similar process in a sense. We put together the various building blocks on the foundation of previous knowledge to build something new and hopefully lasting.
