This month’s Insights Blog features Dr. Cristina Nostro from the University of Toronto, recipient of the 2025 Till & McCulloch Award. Cristina was recognized for her outstanding contribution to global stem cell research through her recent paper in Cell Stem Cell, “Embryonic macrophages support endocrine commitment during human pancreatic differentiation.” 

In this conversation with Joanna Valsamis, SCN’s Director of Knowledge Mobilization, Cristina reflects on her career path, shares highlights from her award-winning research, and offers her perspective on where the field of stem cell research is headed.

Tell us a bit about how your career began. What first drew you to endocrinology, and what inspired you to pursue the research path you’re on today?

First of all, I want to thank the 2025 Till & McCulloch committee for this award. This is such an honor, and I am extremely proud to join a distinguished group of Canadian scientists who paved the way for the remarkable discoveries and clinical translations we are witnessing today. I am also thankful to my present and past teams and my mentors who trusted me and shared their love for science with me.

My journey as a stem cell biologist started in 1998 when I moved from Italy to the UK as an undergraduate student and joined the lab of a stem cell scientist and cancer researcher, Prof. Chris Potten. That was the first time I learned about stem cells (adult), and I was hooked! I then pursued a PhD at the University of Manchester with Dr. Gerard Brady. My discussions with Ged about stem cells, self-renewal and lineage commitment, and lectures from speakers like Gordon Keller, Janet Rossant, Freda Miller, Austin Smith, and Azim Surani inspired and consolidated my quest to become a scientist.

I then joined Gordon Keller as a postdoctoral fellow to fully immerse myself in stem cell biology and explore the potential of embryonic stem cells. In his lab in Toronto, I began focusing on using human embryonic stem cells to treat diabetes, and in 2012, I launched my own lab at the McEwen Stem Cell Institute at University Health Network. It continues to be an inspiration to work in the place where insulin and stem cells were discovered, and where clinical trials are now ongoing to test the safety of human embryonic stem cell–derived products as a new treatment for type 1 diabetes and other diseases.

Congratulations on receiving the 2025 Till & McCulloch Award. Can you walk us through the highlights of your recent publication and share what impact you hope this work will have on future research in the field?

Our work focuses on understanding how different cell types communicate during human pancreatic development. Dr. Adriana Migliorini, a senior postdoctoral fellow in the lab, was particularly interested in determining if the hematopoietic niche provides important cues during islet development, something that has been suggested in mouse studies, but never really explored in humans.

To tackle this, Adriana used single-nucleus RNA sequencing to map the cellular landscape of the developing human pancreas. This allowed her to identify two distinct types of tissue-resident macrophages that had not been described before in this context. She then developed a co-culture system, combining human stem cell-derived macrophages and pancreatic progenitors to model their interaction in vitro. What she found was quite exciting: macrophages actually support endocrine differentiation of pancreatic progenitors and the survival of endocrine cells after transplantation. We speculate that they help create a healthier environment for endocrine cells to both differentiate and engraft, and as such, we can broadly think of macrophages as architects of the developing tissue.

Looking ahead, we are now trying to understand how macrophages provide this support at the molecular level, and whether we can use that knowledge to improve the generation and survival of insulin-producing cells for transplantation. In the long term, we believe this work will help bridge developmental biology and regenerative medicine, and inspire others to think more broadly about how immune cells contribute to organ development and repair.

Throughout your career, you’ve likely met colleagues, mentors, and trainees who’ve left a lasting impression. Looking back, is there one moment, interaction, or person that stands out as especially significant in shaping your journey?

I think at each stage of one’s career, there are several individuals, colleagues and friends, who directly or indirectly guide your path. There are too many people, and often serendipitous moments, that have led to my choices. Of course, a big thank you goes to my parents, who gave me the support and freedom to pursue this career. But these days, I am most grateful to all the students, postdocs, technicians, and volunteers who have joined my lab and trusted me with their dreams, shared their energy, discussed their ideas, and generated data and new hypotheses that have brought the Nostro lab to where it is today.

Science is filled with mysteries still waiting to be solved. If you could unlock the answer to one big unknown, what would it be?

I might be biased, but one of the biggest unsolved mysteries in type 1 diabetes research is understanding what actually triggers the immune system to attack and destroy insulinproducing beta cells. Unlocking the cause of T1D could open the door to therapies that not only prevent or cure T1D, but potentially other autoimmune diseases as well.

On a more personal note, what is something you think everyone should experience at least once in their lifetime?

Without a doubt, everyone should try scuba diving at least once. Below the surface, it is calm and quiet, and all you hear is your own breathing and the bubbles rising around you. You feel weightless, surrounded by the beauty of the underwater world, and if you are lucky, of the coral reef. It really makes you appreciate how vast and beautiful our planet is.

For graduate students and early-career researchers considering a future in stem cell biology and regenerative medicine, what advice would you share? Which skills, experiences, or mindsets do you think are most crucial for success in this field?

For graduate students and early-career researchers interested in stem cell biology and regenerative medicine, my biggest advice is to embrace curiosity and enthusiasm for discovery. Science is at its best when you are excited about asking questions that have not been answered before and that enthusiasm is contagious, often inspiring those around you.

Creativity is also key. Sometimes breakthroughs come from unexpected directions, and even findings that initially seem familiar can lead to new insights when viewed differently. Do not hesitate to connect with scientists in a different field, talk to peers, seek advice from experts, and share your ideas. I also think it is incredibly important to engage with clinicians and patient advocates to understand unmet medical needs; this perspective can help guide your research toward clinical applications.

Finally, gain diverse experiences whenever possible. Travel, rotate through different labs, learn new techniques, and expose yourself to different ways of thinking. These experiences will broaden your perspective, help you develop a strong skill set, and clarify your career goals. In this field, curiosity, creativity, and connection both within science and within the broader healthcare community are just as important as technical skills.

Innovations in stem cell research are constantly emerging. Looking ahead, what are your predictions for the next 5, 10, or even 20 years in this space?

It may sound cliché, but I think regenerative medicine will play a central role in the healthcare of the future. In the next 10 to 20 years, I expect many of the current technical challenges around manufacturing, safety, and scalability to be resolved, making stem cell-based therapies mainstream, affordable, and a first-line treatment for a variety of diseases. I also anticipate that AI and genetic engineering will accelerate these advances, helping us design better therapies, personalize treatments, and even support healthy aging. Ultimately, I see a future where regenerative medicine is fully integrated into healthcare, transforming how we prevent and treat disease.