Department of Bioengineering, Imperial College London
The 8th Biennial Heart Valve Biology & Tissue Engineering Meeting was held in the Royal Society of Medicine, London, UK on 26th to 28th September 2018. This meeting is one of a few specialised and multi-disciplinary meetings that gathers experts from different fields, including biologists, engineers, material scientists, and clinicians, to share and discuss their latest discoveries in valve development and cell biology, pathogenesis of valve calcification, and tissue engineered valves.
As a PhD student working on shear stress-mediated atherogenesis, I have always been interested in exploring how blood fluidic shear stress can play a role in other diseases. Heart valves continuously experience a highly dynamic mechanical environment; hence I am interested in learning more about heart valve mechanobiology and this meeting served as a good venue for me to learn from and to meet experts from the field.
There were a few talks on the mechano-pathology of heart valve calcification that appealed to me. Alan Lam from Professor Craig Simmons’ lab in the University of Toronto, Canada, gave a talk on mechanically directed osteogenesis of valve interstitial cells (VIC) mediated by FHL2-RhoA signaling. Porcine aortic VIC cultured on stiffer collagen-coated silicone (23 kPa) formed more osteogenic aggregates with increased RhoA activation and increased FHL2 nuclear localization as compared to a softer counterpart (7 kPa). This might explain why calcified aortic valve lesions form preferentially in the natively stiffer fibrosa side of the valve leaflet. Nicolas Villa-Roel from Hanjoong Jo’s lab in Georgia Institute of Technology and Emory University, USA, presented his work on the role of miR-483 in shear-induced aortic valve endothelial dysfunction and calcification. He showed that miR-483 is a novel shear-sensitive miRNA in human aortic valve endothelial cells and that it regulates endothelial inflammation, endothelial-to-mesenchymal transition, and valve calcification by inhibiting Ube2c and the HIF1α pathway. miR-483 can be further investigated to explore its therapeutic potential in valve calcification.
Another highlight of this meeting was the debate between Professor Simon Hoerstrup from Wyss Zurich and Technical University Eindhoven, and Professor Ulrich Stock from the Royal Brompton Hospital on the topic of “Do tissue engineered heart valves need to be viable implants?” Professor Hoerstrup, who was on the proposition side, briefed us on the importance of developing viable implants (implantable valves with live cells) that can be implanted into children and adapt to the growth of the patients. He had also reaffirmed that, although viable implants are complex and logistically demanding, that should not be stopping the scientists from developing it because not very far in the future, viable implants could be achievable and affordable for every patient. On the opposition side, Professor Stock disputed the need for a viable implant because of the complexity and cost of making a viable valve for patients. He also emphasized the current urgent need of a simple, ‘foolproof’, cost-effective, and quick solution for patients who are currently suffering from heart valve disease.
On the last day of the meeting, I had the opportunity to interview one of the organizing committee, Dr Adrian Chester, who is a deputy director of research from The Magdi Yacoub Institute and an honorary senior research fellow from National Heart & Lung Institute, Imperial College London. He told me that “The motivation of this meeting is to give a forum for young investigators to present their work in a meeting that is quite intimate and focused on a relatively narrow subject but an expanding field and to give them a chance to meet those established figures in the field. A lot of other valve meetings are dominated by clinical aspects of valve treatment, and the basic science of valve biology is potentially swamped by the clinical discussion. There is no other focused meeting on valve biology and tissue engineering like this one. Heart valve calcification and disease is an entity in itself that offers many interesting questions to address. Knowledge in other cardiovascular diseases is not directly transferable to valve calcification. It is a very important area to investigate because there are a lot of people with valve disease. It is a major cardiovascular entity that deserves and requires basic research,” added Dr Chester. Dr Chester also urged those who are having a research interest in the basic science of valve biology and tissue engineering to contact him.
Last but not least, I would like to thank BSCR for the travel award which contributed towards my expenses. This meeting was an eye-opener and it expanded my knowledge of cardiovascular diseases. I have also had many thought-provoking discussions with experts in the field. I hope that with the knowledge and connections that I have gained from this meeting, I am able to expand my research expertise in the future by venturing into this field of research.