Scientists discover protein that contributes to the onset of heart disease

A multidisciplinary team of researchers led by Henrique Girão, from the Faculty of Medicine of the University of Coimbra (FMUC), has identified a protein that can disrupt the communication between heart cells responsible for the heart contraction signal, thus contributing to the onset of heart disease.

In particular, this study, which involved the Coimbra Hospital and University Centre (CHUC) and the Faculty of Medicine of the University of Porto (FMUP), discovered that "the EHD1 protein is crucial in regulating the distribution and location of a channel - called the gap junction - which is essential for the rapid propagation of the electrical signal ("contraction signal") through the heart muscle and which is at the basis of the synchronised heartbeat", emphasises Henrique Girão.

To better understand the relevance of this research, the results of which have already been published in the prestigious scientific journal Circulation Research, the FMUC researcher explains that "in a healthy heart, to ensure the effective transmission of the 'contraction signal', these channels [gap junctions] are located in specific areas on the surface of the heart muscle cells, called intercalated discs. For this reason, many heart diseases are associated with an abnormal distribution of gap junctions in the heart cells, with their exit from the intercalated disks, which has a negative impact on the efficiency of the propagation of the electrical wave and, consequently, on the contraction force".

In these cases, he explains, "the heartbeat is less vigorous, so less blood is ejected (pumped) with each contraction. In this study, we see how - in diseased hearts - the gap junctions in the heart cells are redistributed. Our results show that EHD1 is involved in the process of removing gap junctions from the intercalated disks, which then leads to their accumulation in other areas of the cell, where the role of these channels in the rapid propagation of the electrical signal is compromised".

The results of this study, which was funded by the Portuguese Foundation for Science and Technology (FCT) and lasted four years, clarify the mechanisms by which this redistribution of gap junctions occurs in the affected heart and allow "the identification of new therapeutic targets that may allow the development in the future of more effective approaches to combat cardiovascular diseases, particularly innovative strategies that prevent the EHD1 protein from participating in the removal of gap junctions from the interim disks, thus guaranteeing a healthy heartbeat", concludes Henrique Girão.

The scientific paper is available at: https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.119.316502

^{Translation by Diana Taborda}