Map of cardiac cells gives new clues about the heartbeat

A team scientist has developed the atlas of human cardiac cells “most detailed and complete to date”which includes the specialized tissue of the cardiac conduction system, where the heartbeat originates heart.

The team is led by the UK’s Wellcome Trust Sanger Institute and the National Heart and Lung Institute at Imperial College London, and has also unveiled a new computational tool called Drug2cell, which can provide insights into the effects of drugs on the heart rate.

The study is part of the international Human Cell Atlas initiative, which is mapping all cell types in the human body to “transform our understanding of health and disease”details the Wellcome.

The work, which represents eight regions of the human heart, describes 75 different cellular states, including the cells of the cardiac conduction system – the group of cells responsible for the heartbeat -, which “until now they were not known in such detail in humans.”

Understanding the biology of conduction system cells and how they differ from muscle cells paves the way for therapies to improve cardiac health and develop specific treatments for arrhythmias.

The study unearthed some unexpected discoveries, according to the researchers. Among them, a close relationship between the cells of the conduction system and the glial cells.

The latter are part of the nervous system and are traditionally found in the brain.

This research suggests that glial cells are in physical contact with cells in the conduction system and may play an important supporting role: communicating with pacemaker cells, which produce electrical impulses that make the heart beat, guiding nerve endings to them and favor its release of glutamate, a neurotransmitter.

Another key finding is an immune structure on the outer surface of the heart. It contains plasma cells that release antibodies into the space around the heart to prevent infection from nearby lungs.

As for Drug2cell, the tool can predict drug targets and drug side effects – it uses the CheEMBL database, which brings together millions of chemical, bioactive and genomic data.

Michela Noseda, from Imperial College London and lead author of the study, notes that “often we are completely unaware of the impact a new treatment will have on the heart and its electrical impulses.”

“Our team has developed Drug2cell to improve the evaluation of new treatments and to know how they can affect the heart and, potentially, other tissues”.

“This could provide us with an invaluable tool to identify new drugs that target specific cells, as well as help predict any potential side effects early in drug development.”

Source: EFE