Nothing in the human body is random, and neither is the position of the central organ of the cardiovascular system. Each organ has a specific location to ensure the correct functioning of the organism, and now scientists have found out the mechanism of this fine engineering of nature: the heart is located on the left due to a pushing force that generates a group of cells in the right side , as detailed in a study published in the journal Nature .
The finding is attributed to a group of researchers from the Neurobiology Unit of the Institute of Neurosciences of Alicante (CSIC-UMH), who have observed in animal embryos what is the biological process that places each organ in its corresponding place, to ensure thus its correct functioning and the perfect concordance with veins and arteries.
Specifically, it is about asymmetric cellular movements and forces , more prominent from the right, that drive the laterality of the heart in vertebrates. These movements are produced thanks to the involvement of certain genes; a mechanism that is conserved in different species, so it can also be extrapolated to humans.
During embryonic development, the heart, like all organs, appears in the midline of the body, and then takes its place. This process was until now unknown to scientists. However, it was thought that there were a series of signals on the right side that were repressed in favor of those on the left side, thus producing asymmetry.
But the study sheds details on those involved in this vital mechanism: the key lies in the genes that induce cell movements. These produce proteins that are responsible for converting an immobile cell into a mobile one. These genes are essential for embryonic development since, as the researchers have described, if these proteins do not work, the embryo does not progress and dies.
“In the early stages of embryonic development, there are many cells that are born very far from their initial position and have to travel long distances to reach their destination “, details Angela Nieto, lead author of the study, in statements to the Sinc Agency.
In the study, carried out with chicken, zebrafish and mouse embryos, the researchers found that, by canceling the function of these genes, the movements of the heart were also canceled, leaving it in the center of the body line.
Pathologies of the heart and metastasis
But these genes turn off on their own after embryonic development is complete. In fact, during adult life they can become active again, leading to serious heart diseases and promoting processes such as cancer. According to Nieto: “There are tumor cells that regain the ability to move, as in embryonic stages, detach from the primary tumor and metastasize to distant organs.”
In addition, a multitude of cardiac pathologies are related to the misplacement of this organ in the body and, probably, after the study’s conclusions, to an inefficient or incorrect activation of the genes responsible for cell mobility.
Researchers estimate that 50% of birth abnormalities are cardiac, and that many of them have to do with an incorrect position of the heart. For example, mesocardia, which is a congenital pathology that occurs when the heart has not moved from its central position.
Reference:
Ocaña, OH, Coskun, H., Minguillón, C., Murawala, P., Tanaka, EM, Galcerán, J., Muñoz-Chapuli, R. and Nieto, MA (2017). A right-handed signaling pathway drives heart looping in vertebrates. Nature In press.
