Coronavirus Can Infect Heart and Brain Cells, Studies Suggest

The coronavirus that causes COVID-19 has been found to infect human heart and brain cells in lab experiments.

The authors of the separate studies said their work shows that SARS-CoV-2 (the coronavirus that causes COVID-19) not only affects the lungs but also appears to have the potential to cause heart and brain problems.

In one paper published in the journal Cell Reports Medicine, scientists watched to see if SARS-CoV-2 could infect human heart cells grown from stem cells in a lab.

SARS-CoV-2 was found to infect the heart cells by attaching itself to ACE2, the enzyme the virus uses to invade our cells. Not only did the virus infect the cells, it replicated and appeared to trigger a type of cell death. After 72 hours, the cells stopped beating. The infection also changed how genes were expressed in the cells, including those relating to turning on a part of the immune system that fights off invaders.

The team said their work shows that SARS-CoV-2 can infect stem cell-grown heart cells in lab dishes, and could be built upon to investigate how the virus affects this organ, and to create potential treatments.

Co-author Clive Svendsen, professor of Medicine and Biomedical Sciences at Cedars-Sinai, said in a statement that while heart problems seen in COVID-19 patients could be the result of the body's inflammatory response to infection, "our data suggest that the heart could also be directly affected by the virus."

In a separate study released as a pre-print on the website ALTEX, SARS-CoV-2 was found to infect the cells of so-called human "minibrains" or "brainspheres" in a lab. SARS-CoV-S entered neural cells of the mini brains, and replicated.

The authors wrote their study provides evidence that SARS-CoV-2 can infect neural cells, and this process likely contributes to neurological problems and possibly neurodevelopmental disorders in those who catch the germ.

Both teams said their studies were limited because the cells were in a lab rather than the human body, where many other processes are at play.

Professor Cris S. Constantinescu of the Division of Clinical Neuroscience at the U.K.'s University of Nottingham Queen's Medical Centre, who did not work on the article, told Newsweek it is thought some of the neurological complications COVID-19 patients experience are indirect and caused by the brain's response to infection.

However, the study represents the "first clear evidence" that SARS-CoV-2 can infect neurons, he said. It also shows that neurons have ACE2.

"This means, that at least theoretically, some of the neurological manifestations of COVID-19 can be caused by direct invasion of the brain cells by the virus."

Dr. Letterio S. Politi of Italy's Humanitas University and Boston Children's Hospital, told Newsweek the study may not be replicable in humans. The blood-brain barrier may block the virus from entering the brain in humans, he said.