Victor Chang Cardiac Research Institute laboratory

Star Scientist - Dr Xenia Kaidonis

When heart cells are damaged, the heart can't repair itself effectively.

2 June 2023

So how can we help the heart regenerate and reduce the risk of heart failure? It’s a question Dr Xenia Kaidonis has thought plenty about since starting with the Institute in 2016. Dr Kaidonis and the Molecular Cardiology Laboratory team are working on cardiac regeneration research that could one day lead to breakthroughs in how we treat those with damaged hearts.

Dr Xenia Kaidonis

Your research at the Institute focuses on cardiac development and regeneration. Can you tell us about this area of study?

Much of what we do is look at heart muscle cells as they grow throughout development. In a young animal, the heart cells divide and the heart gets bigger. But as development continues, these cells stop dividing. The heart continues to get bigger, but only because each cell is growing larger, rather than dividing and making more cells.

My focus is on the biochemical pathways involved in the growth of the heart and what's happening in these pathways to stop the cells from dividing.

The idea is that by understanding these pathways, we could then find a way to restart cell division to repair the heart.

What is your particular focus within cardiac regeneration research?

I'm investigating thyroid hormone, which plays a role in the heart's growth spurt during preadolescence. It does this by causing heart muscle cells to divide, thereby increasing the number of cells in the heart, and allowing it to grow.

Understanding the role of thyroid hormone in the generation of more cells has led us to test whether thyroid hormone can also promote heart muscle cell division in adulthood after a heart attack.

This is important because adult heart muscle cells no longer divide, so after a heart attack, the damaged area is replaced by a rigid scar that stops the heart from pumping efficiently. If we can instead stimulate cell division, we can improve heart repair.

Dr Kaidonis in the Institute's Sydney laboratory

What’s the ultimate aim of this research?

The holy grail would be to find a molecular target to restart cell division in the heart to replace lost cells.

The scar that forms after part of the heart dies due to a heart attack is only really a temporary fix. Over time heart failure can develop, which significantly impacts patient quality of life.

This research may also have applications for people whose hearts haven’t grown or developed properly because of under nutrition or a genetic condition. Some genetic conditions can affect the development of the heart, and under nutrition of children, or their mothers during pregnancy, can lead to children having smaller hearts and an increased risk of cardiovascular disease.

Understanding how the heart should grow normally and how the cells should grow and divide normally could help us target those pathways to reactivate cell division and repair the heart. This may be another area where thyroid hormone, or other molecules it interacts with, could be used to boost heart muscle cell division to increase heart size and improve cardiac outcomes.

But at this stage of the research, it's very much about understanding the biology and those foundational processes.

The head of the lab you work in is the Institute’s former Executive Director Professor Bob Graham. What’s it like working with Professor Graham?

Bob and I work really well together – the whole team works well together actually. It's a very supportive environment.

Professor Bob Graham and Dr Kaidonis

He also brings clinical knowledge that most of the team don't have because most of us in the lab are scientists. He has a real passion for what he does and a fascination with science, right down to minute details. And he's got an amazing memory, so he'll remember everything – the biochemistry of a process, or the shape of a molecule. I’ve found the Institute as a whole to be a good place to work. I like how collaborative it is - it's a nice community of people. Everyone's willing to help everyone else with their work, they don't need something in return. I think that's the nicest thing about working here.

As well as your research, you’re also on the Institute’s Diversity Committee. What led you to being involved in the committee?

I've always had an interest in issues around diversity, equity, and inclusion. I think having a multicultural background has impacted my interest in that area, and awareness of how important it is for us all to work towards making our communities more inclusive.

I know what a difference knowing the local language can make to people's lives, so I'm also involved in tutoring immigrants in English. Any student who is learning English through TAFE can access an hour a week with volunteer tutors and two hours if they’re refugees. It’s a really rewarding program to be a part of.

Where did your interest in science come from?

I really loved biology at school and that's what led me down the path of studying science at Uni - though I didn't get into science really understanding what it would be like as a career. It's not a career course like doing say a physiotherapy course and becoming a physiotherapist. Being a scientist is more about continuing knowledge and study.

I then developed an interest in molecular biology, which is like working on a puzzle. I enjoy the critical thinking and creativity it takes to solve a problem.

Outside of the science world, what are you passionate about?

I love food, cooking, going to gigs, bush walking and camping. When I was nine, my family and I went camping for three months across Australia. I’ve always been inquisitive, and I guess I grew up thinking that way because we were immersed in nature.

Xenia surveying a beautiful view while bushwalking

I also love to travel and one of my favourite things about travelling is the food. My most recent trip was to a friend's birthday celebrations in Bali last year. I would never have thought to go to Bali because I usually avoid resort style holidays, but I had a great time and the food was fantastic. I did a cooking class and went to some amazing night markets with really great street food.

Of all the places you’ve travelled, where’s your favourite place to eat?

I love French food – both cooking it and eating it. I shouldn't say this when I work at a cardiovascular institute, but I love cream and butter (laughs).

Acknowledgement of Country

The Victor Chang Cardiac Research Institute acknowledges Traditional Owners of Country throughout Australia and recognises the continuing connection to lands, waters and communities. We pay our respect to Aboriginal and Torres Strait Islander cultures; and to Elders past and present.

Victor Chang Cardiac Research Institute - The Home of Heart Research for 30 Years