Please meet Prof Julie McMullen, the new Deputy Director and Director of Research at the Heart Research Institute (HRI).
Prof McMullen joined HRI in July and is an internationally-recognised figure in the field of cardiovascular research with over 25 years’ experience. We are so lucky to have one of Australia’s foremost heart biology scientists at the Institute who is striving to make a difference for patients with heart failure and other cardiovascular complications.
What is your background?
I grew up in Sydney and did my PhD at the University of NSW. I was fortunate to then be offered a postdoc position at Harvard Medical School and Beth Israel Deaconess Medical Centre in Boston.
I came back to Australia in 2005 to establish my first laboratory as an independent investigator at the Baker Heart and Diabetes Institute in Melbourne. It’s great to be back in Sydney at HRI and set up a new team here called the Heart Muscle Group.
What is the focus of your research?
The broad theme of my research came about because of my interest in understanding why an enlarged heart is good in some people and bad in others. The heart enlarges in elite athletes or people who exercise a lot, and this heart growth is beneficial. Conversely, the heart also enlarges in people with heart disease or heart failure, but this heart growth is bad.
My research has focused on understanding those differences at the genetic level, and we identified a gene that is critical for the beneficial heart growth that occurs with exercise – the PI3K gene.
One of the things we are trying to do is improve the heart function of people with a failing heart so they don’t get breathless and can undertake normal everyday tasks. Our goal is to mimic the beneficial effects of exercise in the failing heart by developing new drugs. This will improve heart function and reduce the risk of heart disease or heart failure, which is increasing in Australia and globally.
The newly formed Heart Muscle Group (right) is led by Prof Julie McMullen
“Our team is also very interested in cardio-oncology and the fact that many cancer treatments are leading to cardiac complications like heart failure or atrial fibrillation (AF) down the track.”
Sometimes these complications don’t show up until many years later. It is important we can identify new biomarkers and therapeutic strategies for this challenging and understudied area.
I’m also looking at how the heart communicates with other organs in the body as this could help treat multi-morbidity, which is a significant clinical issue.
In each of these areas, we study differences between males and females, as we know males and females often present differently in settings of heart disease and in response to treatments.
Why did you decide to join HRI?
What really attracted me to HRI is the great fundamental research being performed, and that there are opportunities to collaborate and link with researchers and clinicians at universities like The University of Sydney and hospitals like the Royal Prince Alfred Hospital. This large team collaboration means we have greater opportunities to translate our findings in the laboratory and really make a difference for patients with heart disease.
In my new role as Deputy Director and Director of Research, it is also an opportunity to help shape the research program and mentor up and coming Group leaders. An important aspect of my role, and one I find very rewarding, is to give researchers the best opportunity to succeed and reach their full potential.
Finally, I’m excited to support and collaborate with the Djurali Centre to really make a difference for Indigenous communities. That’s very unique to HRI.
What do you consider your greatest discovery?
Showing that PI3K is critical for exercise-induced heart growth is my most recognised discovery to date. It has also led me into the other research areas. For example, we realised that when this same gene was decreased in the heart, it made it more susceptible to AF, which is now another big focus of my research.
Understanding AF is really important because once people have AF, it's incredibly hard to reverse. So my team and I are working hard to develop a simple blood test to predict when people are more susceptible.
One thing I have learnt in my career is you have to be very open to the unexpected and the serendipitous findings because some of those findings have resulted in the most key discoveries. To identify an unanswered question or knowledge gap, and undertake experiments to make a discovery that will hopefully one day make a difference, is an absolute privilege.
Prof McMullen with HRI's Dr Carmine Gentile and London-based consultant cardiologist Dr Alexander Lyon
Why are you so passionate about cardiovascular research?
While at school and during my university studies I became aware of relatives, friends or stories in the media of people being significantly impacted by heart disease. Cardiovascular disease is the leading cause of disability and death in Australia. A career in heart research allowed me to combine my passion for science with the hope of making a difference for people with heart disease.
“My grandmother had high blood pressure and developed heart failure.”
I remember visiting her as a young girl and helping her dispense the multiple tablets she had to take every morning, which she used to hate. She was a passionate gardener and cook, and those tasks were so much more difficult when she was breathless (a common symptom of heart failure). It’s terrible that people with heart failure, who are so mentally well, can’t do simple everyday tasks we take for granted.
Another event that impacted me early in my career was when a father contacted me because his son had died unexpectedly in his sleep. Only after the event, it was discovered their son had a heart condition they had no prior knowledge of. The boy’s parents were understandably upset and distraught. My hope is that one day we’ll find a reliable biomarker so we can identify people at risk with a routine blood test so that we can prevent these tragic events from happening. It is just so devastating for the families who experience this loss unexpectedly.
It's also alarming how many people with end stage heart failure don’t make it onto the heart transplant list or die while on the waiting list. That’s why we desperately need new therapies. Gene therapy is just one promising new approach, and with more research, treatment could be a single injection in a day clinic that lasts for months or even years.
Research provides an opportunity to give individuals a better quality of life for longer, and to prevent unexpected cardiac events or death.
Did you always want a career in science, and how passionate are you about mentoring women in STEMM?
As a child, I was always fascinated by science. I was lucky to have some excellent science teachers, and it was my favourite subject at school.
I did my PhD in a laboratory where I had two female supervisors, and one was the Department Head. On reflection, that significantly impacted me because I never saw the stereotypes of only male professors being in those roles. Being in an environment with strong female leaders, I just thought that was normal. It wasn't until later in my career that I saw the difficulties for females attaining these leadership roles.
I’ve been fortunate to be well supported and offered leadership roles throughout my career. I really hope that women in STEMM see female leaders like myself and others as evidence that anything is possible, and realise that leaders can have different types of traits and personalities.
Mentoring female students and researchers and watching them reach their full potential, is one of the most rewarding aspects of my role.
