Despite massive amounts of ongoing research into severe acute respiratory syndrome ­coronavirus 2 (SARS-CoV-2), the virus that causes the coronavirus disease 2019 (COVID-19), researchers have yet to discover the location of the receptor, a major step to discovering effective treatments.

According to research conducted by the Masonic Medical Research Institute, in collaboration with the Broad Institute, the University of Pennsylvania, and Bayer US, nearly 20% of all deaths associated with COVID-19 are from cardiac complications, although the exact mechanisms are still unknown. One hypothesis theorizes about the infection of the heart itself, but it is unclear which exact cells may be infected, according to the researchers.

In an effort to address these knowledge gaps, investigators researched the distribution of the SARS-CoV-2 receptor. They found that COVID-19 infects cells through the angiotensin-converting enzyme 2 (ACE2) cellular molecule, and to further assess the levels of this molecule in different patients they used single nucleus sequencing technologies in human heart samples. Based on these studies, they found that the amount of the receptor is increased in patients with pre-existing cardiac conditions, but only in the cardiomyocytes.

In addition, the researchers found that the effect of ACE inhibitors does not appreciably affect the levels of ACE2 enough to support any changes in the clinical use of these medications.

“This is an early step in our understanding of cardiac pathology in people who contract COVID-19,” said first author Nathan Tucker, PhD, in a statement. “There’s much more work to do.”

Tucker added that the team is already working to establish direct evidence of cardiac infection, as well as examining receptor distributions in other populations and through different approaches.

COVID-19 and the Heart: Searching for the Location of the SARS-CoV-2 Receptor [news release]. Masonic Medical Research Institute; June 24, 2020. Accessed July 23, 2020.