24 September, Cambridge – Scientists have created a cellular and molecular map of the healthy human heart, to understand how this vital organ functions, and to shed light on what goes wrong in cardiovascular disease.

Researchers from the Wellcome Sanger Institute, Max Delbrück Center for Molecular Medicine (MDC) in Germany, Harvard Medical School, Imperial College London, EMBL-EBI and their global collaborators analysed almost half a million individual cells to build a first extensive draft cell atlas of the human heart. The atlas shows the huge diversity of cells and reveals heart muscle cell types, cardiac protective immune cells, and the intricate network of blood vessels. It also predicts how the cells communicate to keep the heart working.

The work, published in the journal Nature, is part of the Human Cell Atlas initiative to map every cell type in the human body. The new molecular and cellular knowledge of the heart will enable better understanding of heart disease and guide more personalised medicine. It could also potentially lead to regenerative medicine in the future.

Cardiovascular disease is the leading cause of death worldwide, killing an estimated 17.9 million people each year, with heart attacks and strokes causing the majority of these. To understand what happens during heart disease and create better therapeutic strategies, it is vital to know the intricate molecular processes in the cells of the healthy heart.

In this new study, researchers studied nearly 500,000 individual cells and cell nuclei from six different regions of healthy hearts from 14 organ donors*. Using cutting-edge, single-cell technology, machine learning and imaging techniques, the team could see exactly which genes were switched on in each cell.

The researchers discovered that there were major differences in the cells in different areas of the heart, and that each area of the heart had specific sets of cells, highlighting different developmental origins and potentially different responses to treatments.

Dr Carlos Talavera-López, one of the first authors from the Wellcome Sanger Institute, and previously at the EMBL European Bioinformatics Institute, said: “We have created the most detailed atlas of the human adult heart to date combining single-cell technologies with artificial intelligence methods, to characterise almost half a million single cells. For the first time, we could see exactly what each cell is doing in the human heart. This atlas shows that the cells in each of the four chambers of the heart behave differently to each other, mirroring the different functions of each area and helping us understand the healthy human heart.”

Read the full press release on the Wellcome Sanger Institute website. 

*Hearts were donated from 14 organ donors whose hearts were healthy but not suitable for organ transplantation for a number of reasons. We are grateful to the deceased donors and their families for their invaluable gift. All data from this study can be explored on the Heart Cell Atlas website.  ​

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