Melbourne researchers have created human heart valve tissues from stem cells, providing a powerful new platform to advance treatments for childhood heart diseases.
The world-first discovery, led by Murdoch Children's Research Institute (MCRI) , has produced lab grown heart valve tissues that closely resemble those in the human body. Published in Cell Stem Cell , the findings advance our understanding into how human heart valves develop, mature and become damaged.
MCRI Dr Holly Voges , also an Associate Investigator at the Novo Nordisk Foundation Centre for Stem Cell Medicine (reNEW) , said the breakthrough would help accelerate regenerative approaches for repairing damaged valves in children and adults.
Heart valve disease is a major global health issue, affecting about 28 million people. Heart valve disease occurs when one or more of the heart's four valves don't open or close properly, disrupting blood flow. Left untreated, it may cause the heart to work harder and ultimately become life-threatening.
"Heart valve disease can be caused by developmental abnormalities, infection or age-related degeneration," Dr Voges said. "Currently there are no treatments that can reverse the damage. Most patients depend on valve replacement surgery, which has significant limitations, including a high risk of blood clots and, for children, the likelihood of needing multiple procedures over their lifetime.
"To overcome this, our team has addressed a major challenge in heart valve biology. By creating heart valve tissues that mimic the molecular features of a human version we can now test and advance new treatments at scale in the lab."
The researchers also showed that the platform could model inflammatory valve disease, an underlying precursor to rheumatic heart disease (RHD).
Australia has some of the highest recorded rates of RHD in the world. The disease is largely preventable, disproportionately impacts Indigenous populations.
"When exposed to inflammatory proteins linked to rheumatic heart disease discovered in previous studies, we found the engineered stem cell tissues became stiffer and showed biomarkers consistent with diseased human valves," Dr Voges said.
MCRI Professor Enzo Porrello , also Director of the Melbourne node of reNEW, said, "Engineered stem cells have enabled us to closely recreate the complex structure of human valve tissue. In the future, this technology could be used to more accurately model valve disease and support the development of stem cell-derived replacement valves that grow and adapt with a patient."
Emily, 7, has a congenital heart defect (tetralogy of Fallot with absent pulmonary valve), which impacts the flow of blood between the heart and lungs.
Doctors had prepared the family for a serious heart condition diagnosis, as prenatal scans had detected something was amiss. But the full extent of Emily's condition only became clear after she was born at almost 42 weeks' gestation.
Mum Jessica said Emily was expected to arrive early and with many complications.
"We were told that Emily would most likely be born early, have significant developmental delays, behavioural issues and poor quality of life," she said. "Instead, she was born over her due date and bright pink, not blue as other babies with heart conditions often are."
Although Emily appeared healthy, her serious underlying condition required open-heart surgery within five hours of birth and a temporary shunt to supply blood to her lungs.
Emily underwent another surgery at five months old, with her shunt successfully replaced with a new valve. But with no cure, she will likely need a replacement valve in her teenage years to match her adult-sized heart.
Jessica said, over the course of the medical care, Emily's doctors also discovered her heart was positioned in an unusual way.
"Emily has an exceptionally rare combination of heart defects, but she has thrived in spite of it," Jessica said. "She achieved her early milestones and started prep last year. She loves being outdoors, playing with her school friends and painting and drawing, which she puts her whole heart into. With the help of the cardiologist team, we have so much optimism for her future."
The family recently visited MCRI to tour the stem cell facilities and the Melbourne Children's Heart Tissue Bank where Emily's donated heart tissue is kept frozen for future research projects. The specialised biobank, established with support from The Royal Children's Hospital Foundation, underpins research into the causes of childhood heart disease.
Jessica said it was remarkable to meet the team behind this latest stem cell discovery.
"By contributing to the biobank, we were proud we could participate and help make the future brighter for children just like Emily, born with damaged or absent heart valves, who might require further treatments," she said. "This pioneering research fills us with so much comfort."
Researchers from the University of Melbourne, Baker Heart and Diabetes Institute, Peter MacCallum Cancer Centre, Monash University, QIMR Berghofer, Olivia Newton John Cancer Research Center and The Royal Children's Hospital also contributed to the findings.
Publication: Holly K. Voges, Jessica Durrant-Whyte, Michael See, Valerii Iaprintsev, Serene Yeow, Benjamin L. Parker, Kaitlyn Bibby, Ellen Keen, Ingrid King, Adam T. Piers, Anita C. Thomas, Daniel G. Donner, Akriti Varshney, Sara Alaei, David Yoannidis, Timothy Semple, Natalie Charitakis, Jerico Revote, Adriano Morandini, Purva Kumbhar, Rebecca Sutton, Francesca Butera, Edouard G Stanely, Jana Hagen, Janice D. Reid, James E. Hudson, Amr Allam , Sara Ellis, Lina H. H. Le, James P. Burgess, Sean J. Humphrey, Salvatore Pepe, Hazem Alkazemi, Daniel E. Heath, Mirana Ramialison, Fernando J. Rossello, Christian P. Brizard, David A. Elliott, Alejandro Hidalgo and Enzo R. Porrello. 'Human heart valve-like tissues from pluripotent stem cells with enhanced maturation recapitulate inflammatory valve disease,' Cell Stem Cell. DOI: 10.1016/j.stem.2026.07.010
*The content of this communication is the sole responsibility of MCRI and does not reflect the views of the NHMRC.
