There is still a lot that we don’t understand about SARS-CoV-2 (COVID-19), the new coronavirus that has caused a worldwide pandemic. Some patients that contract the virus experiences heart problems, but the reasons are not entirely clear. Pre-existing heart conditions or inflammation and oxygen deprivation that result from COVID-19 have all been implicated but more evidence needs to be collected.
To evaluate this, a joint study between Cedars-Sinai Board of Governors Regenerative Medicine Institute and the UCLA Broad Stem Cell Research Center used human induced pluripotent stem cells (iPSCs), a kind of stem cell that can become any kind of cell in the body and is usually made from skin cells. The iPSCS were converted into heart cells and infected with COVID-19 in order to study the effects of the virus.
The results of this study showed that the iPSC-derived heart cells are susceptible to COVID-19 infection and that the virus can quickly divide inside the heart cells. Furthermore, the infected heart cells showed changes in their ability to beat 72 hours after infection.
In a press release, Dr. Clive Svendsen, senior and co-corresponding author of the study and director of the Cedars-Sinai Board of Governors Regenerative Medicine Institute, elaborated on the results.
“This viral pandemic is predominately defined by respiratory symptoms, but there are also cardiac complications, including arrhythmias, heart failure and viral myocarditis. While this could be the result of massive inflammation in response to the virus, our data suggest that the heart could also be directly affected by the virus in COVID-19.”
Although this study does not perfectly replicate the conditions inside the human body, the iPSC heart cells may also help identify and screen new potential drugs that could alleviate viral infection of the heart.
The research team has already found that treatment with an antibody called ACE2 was able to decrease viral replication on the iPSC heart cells.
In the same press release Dr. Arun Sharma, first author and another co-corresponding author of the study and a research fellow at the Cedars-Sinai Board of Governors Regenerative Medicine Institute, had this to say about the ACE2 antibody.
“By blocking the ACE2 protein with an antibody, the virus is not as easily able to bind to the ACE2 protein, and thus cannot easily enter the cell. This not only helps us understand the mechanisms of how this virus functions, but also suggests therapeutic approaches that could be used as a potential treatment for SARS-CoV-2 infection.”
The study’s third co-corresponding author was Dr. Vaithilingaraja Arumugaswami, an associate professor of molecular and medical pharmacology at the David Geffen School of Medicine at UCLA and member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research.
The full results of this study were published in Cell Reports Medicine.
The Stem Cellar 
WHO reported that Covid-19 infections in the world were dominated by G strain which was officially named as D614G. The finding showed that majority of outbreak of Covid-19 infection in Europe and USA was associated with D614G. Further investigation found that mutation strain of virus had more spike proteins and the spike protein more effective to enhance virus’s infectioness. Spike proteins are formed in outer parts of virus. The mutation form of spike proteins are less likely to break off, which are more stable and have almost 10X infection rate. The advantage of this mutated spike proteins allowing those structures to change shape and improve the ability to fuse to host cell. The first outbreak of Covid-19 infection in China cause more destructive in lung of majority infected people. Time after time, when the virus spread widely accross the world, the virus not only makes destruction in lung but kidneys, blood vessels and heart tissue of victims. It is uncertain whether mutation of D614G strain cause more organs failure in infected patients. In USA, there was high fatality rate in youngers contracted with Covid-19, but no indication of virus strains was reported. The determination of virus strains to each patient provide important clues related to severe damage of the virus on the health of patients. Experimental study of pluripotent stem cells(PSCs) which are not mature cells, but early culture of organoids provides limitation biological information of related tissue and organ. However, this in vitro study still valid to give little insight of pathogenic effect of Covid-19 infection in tissue and organ of human beings. The administration of drugs in vivo has no correlation with in vitro study. Different tissues and organs have various sensitivity, response and toxicity toward the effects of drugs. Therefore, the pharmacology action of a drug in multiple organs of one organism cannot be translated by in vitro culture study.