BarcelonaThe heart is the first organ to develop in humans, and its function depends, above all, on its shape. It is our engine, responsible for sending blood to the rest of the organs that allow us to live. But in order for it to function properly, all its structures must work in absolute coordination. When this does not happen, abnormalities develop in children, the most common birth defect being congenital heart disease, and dysfunctions in adults, such as arrhythmias and severe valve disease. To prevent these diseases, it is necessary to understand how the different cells that create these complex structures are organized and are essential for the functioning of our motor. Now, researchers at the University of California San Diego have produced a comprehensive atlas of human heart development from organoids from fetuses aged 9 to 16 weeks.
The study was published Wednesday in the journal nature,It reveals how cells interact through a series of volume maps, which should lead not only to a better understanding of the mechanisms of these diseases, but also to the development of new strategies for heart repair. In recent years, the scientific literature has published a list of the different cell types of the adult human heart and its cardiac progenitors using RNA sequencing. However, researchers have now combined this gene expression analysis with a molecular imaging technique called MERFISH, which has made it possible to discover how subpopulations of heart cells are distributed and how they interact with each other as the organ develops.
With all this, the researchers created a volumetric map of the cornerstone of blood circulation. Through this double analysis, American scientists found that there are up to 75 different types of cells, which, although their characteristics are similar, are not evenly distributed. In fact, they have been shown to be organized into 14 subpopulations or cell communities that, during embryogenesis, give rise to the tissues that will eventually form the heart.
Using MERFISH, researchers simultaneously observed hundreds of thousands of genes in a single heart cell. By combining the molecular study of individual cells, they created this size map that allows us to get unprecedented resolution and a deep understanding of these heart cells; And also how they reside inside the heart. The authors discovered interactions between specific groups of cell populations. For example, interactions that may play a key role in ventricular wall formation are between ventricular cardiomyocytes, connective tissue cells known as fibroblasts, and endothelial cells, which line blood vessels.
Testing animal cells and stem cells
The heart consists of four main parts: the atria, which receive blood from the blood vessels, and the ventricles, which pump it throughout the body. Most cell communities are located in these cavities, although there are also some hidden behind the formation of the tricuspid and mitral valves, responsible for promoting blood flow from one “cavity to another”. Of all the parts that make up the heart, the ventricles have the most complex cellular organization. To understand how different types of heart and blood vessel cells coordinate to form key structures that regulate heart function, the researchers analyzed and then examined animal hearts. in the laboratory With cardiac stem cells of human origin.
Researchers have investigated and identified the specific cell lineages that make up the organ as it develops. In total, they sequenced the RNA of 142,946 individual cells collected. Once analyzed, they grouped them based on their characteristics and divided them into up to 75 subgroups based on their anatomical location and stage of development.
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