Infection with SARS-CoV-2, the virus that causes COVID-19, can produce a wide range of symptoms. Some patients experience heart complications with COVID-19 such as a change in heart rhythm. Some patients have suffered damage to the heart cells which has led to heart attacks, while others have experienced circulatory system changes which have led to blood clots forming.
The most common symptoms experienced by COVID-19 patients are fever, cough, shortness of breath, loss of taste and smell, and pneumonia, but neurological symptoms are seen in some patients and heart problems also occur. Heart symptoms are now widely accepted as being associated with COVID-19, but what is not entirely clear is why that is the case – Whether the virus attacks the heart and causes heart symptoms directly, or if heart problems are due to the ischemic and inflammatory responses that are caused by COVID-19. New research suggests that the heart symptoms are directly caused by the virus.
The study showed that SARS-CoV-2 can attack the heart directly, using the same cell-surface receptors (ACE2) that are used to gain entry into lung cells. Once the virus enters cardiomyocytes, cell function changes, which causes the heart symptoms seen by physicians.
To study the effect of SARS-CoV-2 on heart cells, the researchers used cardiomyocytes obtained from Induced Pluripotent Stem Cells (IPSCs). The researchers then used the human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) as a model to examine the effect of infection with SARS-CoV-2.
The researchers showed SARS-CoV-2 could infect heart cells via the ACE2 receptor. After entering the cells, viral replication and the cytopathic effect induced hiPSC-CM apoptosis and cessation of beating after 72 hours of infection.
The researchers also studied the genes that were active before and after infection with SARS-CoV-2. “SARS-CoV-2 infection activates [the] innate immune response and antiviral clearance gene pathways, while inhibiting metabolic pathways and suppressing ACE2 expression,” explained the researchers. The researchers also showed that blocking the ACE2 protein with an antibody made it more difficult for the virus to bind and enter the cells.
“These studies show that SARS-CoV-2 can infect hiPSC-CMs in vitro, establishing a model for elucidating infection mechanisms and potentially a cardiac-specific antiviral drug screening platform,” suggested the researchers.
You can read more about the study in the paper – Human iPSC-Derived Cardiomyocytes , are Susceptible to SARS-CoV-2 Infection – which was recently published in the journal Cell Reports Medicine. DOI: 10.1016/j.xcrm.2020.100052