Extracellular vesicle production Microvesicles 100-1000nm
Extracellular vesicle subpopulation separation
Organelles miRNA Early endosome
Project Objectives RNA
Cardiac Progenitor Cell (CPC)
Increased vessel density
Golgi Stress signals thrombin DNA damage intracellular calcium extracellular ATP LPS hypoxia
Apoptic bodies 1-5μm
Extracellular vesicle engineering
Inhibition of cardiomyocyte death
Over 3.5 million people are diagnosed with heart failure in Europe every year, and their long-term prognosis is poor. Researchers in the Evicare project are developing an innovative therapy that could help to stimulate the repair of cardiac tissue and change the course of heart disease, as Professor Joost Sluijter explains. A number of
measures are commonly used to treat heart disease, such as lifestyle changes and certain medications like betablockers and ACE inhibitors, yet these typically only slow the progression of the disease. With heart failure the most common cause of death across the world, there is a clear need for effective new therapies, a topic at the heart of the Evicare project’s work. “We are looking into manipulating the response of the heart to injury, helping it to repair itself, so that we can essentially prevent heart failure,” outlines Professor Sluijter, the project’s Principal Investigator. This work centres on using stem-cell derived extracellular vesicles, containing nature’s own biological materials, to help repair the damaged organ. “One part of our research involves looking at the mechanisms of how this works. If you add the vesicles into the damaged organ, how does it help the repair mechanisms? Which cell types are targeted and which processes are affected?” explains Professor Sluijter.
Extracellular vesicles The aim here is to stimulate endogenous mechanisms in the heart using extracellular vesicles, which typically contain a mixture
of proteins and different RNA species. These vesicles, which are derived from stem cells or made of synthetic materials, or a hybrid of the two, are being studied within the project on essentially three levels. “One part involves looking at the vesicle itself. We are looking to characterise the vesicles on the RNA and protein level, and we’re also investigating items like their density and size,” says Professor Sluijter. Researchers are also investigating the impact of these
A lot of attention within the project is focused on the question of how to deliver these extracellular vesicles to the location where they are required to help stimulate cardiac repair. These extracellular vesicles are so small that they could be moved away from the heart relatively easily, so Professor Sluijter says it’s important that they are delivered as accurately as possible to damaged parts of the organ. “We’re investigating how we can produce enough vesicles and how we can get them to the right location,” he says.
If you want to kick-start
a chronically ill heart and repair it effectively, then a single injection is unlikely to be enough. That’s why we think that local, slow-release systems are essential.
vesicles on certain cell culture systems. “We do in vitro studies where we put those vesicles on different cardiac cells in a culture model, and then we assess how they behave. The third level is where we go to in vivo studies – where we use pre-clinical animal models, mainly in rodents. There, we treat diseased hearts with the vesicles,” explains Professor Sluijter.
While it is possible to inject vesicles into the bloodstream, Professor Sluijter believes that a more localised approach is necessary in terms of the project’s wider objectives. “If you want to kick-start a chronically ill heart and repair it effectively, then a single injection is unlikely to be enough,” he continues. “That’s why we think that local, slow-release systems are essential. For a patient, it will mean a single operation.”
The vesicles will be encapsulated in materials that facilitate the slow release of biomaterials over an extended period, rather than a single exposure. These vesicles are designed to ensure that they cannot be flushed out easily, but instead slowly get into the organ and then affect the cells that they need to affect, with the ultimate goal of restoring an individual’s heart function. “It’s about restoring the natural blood supply and the contractility of the heart,” says Professor Sluijter. The dosage of extracellular vesicles required to achieve this may vary according to the extent and location of damage in the heart; for now however, Professor Sluijter says the priority is to improve blood flow in the diseased organ. “We’re aiming to help certain cell types survive in the diseased heart, and to achieve better perfusion,” he explains.
Treatment and prevention This approach could potentially be used both in treating people who have experienced serious cardiac problems, and also in prevention. While Professor Sluijter does not envisage using the extracellular vesicles on healthy individuals, he believes they could help change the course of heart disease in some patients. “It may be that we can start treating a certain population earlier, for example people who have an injured heart due to a myocardial infarction. It might be possible to treat people with diabetes, or other people at high risk of developing heart failure,” he outlines. The vesicles could also be used to bring other drugs into the heart, another issue that Professor Sluijter and his colleagues in the project are exploring. “We see the vesicles as
Heart failure is a growing chronic disease with a 50% mortality within 4 years. There is a major need for more innovative, regenerative therapies that have the potential to change the course of disease. We aim to recondition heart failure by stimulating cardiac repair with extracellular vesicles that are derived from progenitor cells.
This work was supported by the Project EVICARE (No. 725229) of the European Research Council (ERC) and PPS grant (No. 2018B014) of the Dutch Heart Foundation.
A kick-start for the damaged heart
Extracellular Vesicle-Inspired CArdiac Repair
a natural way of getting into a target cell and affecting that cell type,” he explains. The next step beyond this could be to load different biological species or other drugs into these vesicles, which opens up the possibility of using them to treat a variety of other conditions. A key challenge here remains delivering the vesicles to the ideal location, which will remain the focus of a lot of attention in research. “That’s one of the key issues in the project,” stresses Professor Sluijter. Researchers have learned a great deal about how to isolate and characterise these vesicles over the course of the project, and Professor Sluijter is keen to make further progress in the years ahead. “In the future we will aim to move forward towards local applications,” he continues. “Further ahead, we will look towards designing these vesicles. A hybrid of synthetic and natural materials is likely to be more effective than natural materials on their own.” The ultimate long-term goal is to use this approach to help regenerate the heart and limit the impact of heart disease, which is a major priority for health authorities across the world. This is not an immediate prospect however, and at this stage researchers aim more to demonstrate the feasibility of using extracellular vesicles to repair the heart, laying the foundations for further development in the future. “With this project, we want to show that we can manipulate vesicles around the heart, to demonstrate that it can be done,” says Professor Sluijter. “We aim to show that this approach works in a natural way, and that we can make these hybrid extracellular vesicles for a clinical phase trial.”
Project Coordinator, Professor Joost Sluijter UMC UTRECHT Heidelberglaan 100 3584 CX Utrecht E: J.Sluijter@umcutrecht.nl W: sluijterlab.com · Mol EA, Lei Z, Roefs MT, Bakker MH, Goumans MJ, Doevendans PA, Dankers PYW, Vader P, Sluijter JPG. Injectable Supramolecular Ureidopyrimidinone Hydrogels Provide Sustained Release of Extracellular Vesicle Therapeutics. Adv Healthc Mater. 2019 Oct;8(20):e1900847. · Maring JA, Lodder K, Mol E, Verhage V, Wiesmeijer KC, Dingenouts CKE, Moerkamp AT, Deddens JC, Vader P, Smits AM, Sluijter JPG, Goumans MJ. Cardiac Progenitor Cell-Derived Extracellular Vesicles Reduce Infarct Size and Associate with Increased Cardiovascular Cell Proliferation. J Cardiovasc Transl Res. 2019 Feb;12(1):5-17. · Sluijter JPG, Davidson SM, Boulanger CM, Buzás EI, de Kleijn DPV, Engel FB, Giricz Z, Hausenloy DJ, Kishore R, Lecour S, Leor J, Madonna R, Perrino C, Prunier F, Sahoo S, Schiffelers RM, Schulz R, Van Laake LW, Ytrehus K, Ferdinandy P. Extracellular vesicles in diagnostics and therapy of the ischaemic heart: Position Paper from the Working Group on Cellular Biology of the Heart of the European Society of Cardiology. Cardiovasc Res. 2018 Jan 1;114(1):19-34.
Professor Joost Sluijter
Professor Joost Sluijter is a Medical Biologist and heading the Experimental Cardiology Laboratory in which he is focussed on stimulating cardiac regeneration, thereby using advanced technologies of cardiac tissue engineering and the use of secreted progenitor cell vesicles to induce cardiac repair. He is awardee of an ERC consolidator grant.