Canadian Blood Services discovery research team publishes new findings on the intricacies of liver cells & platelets

The Proceedings of the National Academy of Sciences (PNAS) scientific journal is a globally recognized publisher of biological, physical, and social science findings. Among its latest contributors is Dr. Heyu Ni, a Canadian Blood Services senior scientist, professor at the University of Toronto, and a scientist with Unity Health Toronto.  Dr. Ni and his team undertake studies focused primarily on platelet biology and immunology.

In a new article published in PNAS in September 2025, Dr. Ni’s team provides answers to questions about the role of Kupffer cells – specialized cells located in the liver – and how they affect the number of platelets circulating in an individual’s veins (platelet count). In particular, this work focuses on the intricacies affecting generation of the hormone thrombopoietin (TPO), which is a key regulator of platelet counts.

While earlier studies have connected Kupffer cells to platelet “clearance” (removal), Dr. Ni’s lab has generated new evidence to show that these Kupffer cells are actually a necessary part of the mechanism that mediates TPO generation, too.

Essentially, this research provides evidence to show that Kupffer cells play a role in creating small holes in the cellular lining of blood vessels within the liver. These small holes (endothelial fenestrations) allow platelets to collect and interact with the other liver cells (hepatocytes) and platelet glycoproteins (GPIbα) in a way that supports generation of TPO. When Kupffer cells were depleted in the mouse models the team studied, fewer holes were seen and lower TPO levels were observed. Previous studies from Dr. Ni’s team have discovered the role of GPIbα in regulating TPO production, too.  

Increased understanding of mechanisms involved in platelet clearance is particularly important in the treatment of patients who have a low platelet count that puts them at a greater risk of uncontrolled bleeding. With further studies, it could also generate information about whether targeting specific receptors involved in the Kupffer cell-platelet clearance process could offer new and effective therapies.

While the findings published in PNAS are exciting, Dr. Ni’s team is already looking ahead. Says Dr. Ni:

“These findings provide novel understandings for platelet homeostasis and should have broad implications in hematology, liver pathophysiology and related diseases. It may be worthwhile to test whether nanoparticles carrying GPIbα can be used to induce TPO production and treat thrombocytopenic patients”. 

Dr. Ni’s laboratory receives support from Canadian Blood Services including through competitive funding programs such as the Intramural Research Grant Program, and Postdoctoral Fellowship Program. He has also received grants from Canadian Institutes of Health Research (CIHR) as well as Heart and Stroke Foundation of Canada.

Canadian Blood Services – Driving world-class innovation 

Through discovery, development and applied research, Canadian Blood Services drives world-class innovation in blood transfusion, cellular therapy and transplantation—bringing clarity and insight to an increasingly complex healthcare future. Our dedicated research team and extended network of partners engage in exploratory and applied research to create new knowledge, inform and enhance best practices, contribute to the development of new services and technologies, and build capacity through training and collaboration. Find out more about our research impact.  

The opinions reflected in this post are those of the author and do not necessarily reflect the opinions of Canadian Blood Services nor do they reflect the views of Health Canada or any other funding agency.