Detection of Viral RNA Fragments in Human iPSC-Cardiomyocytes following Treatment with Extracellular Vesicles from SARS-CoV-2 Coding-Sequence-Overexpressing Lung Epithelial Cells

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global pandemic. The prevalence/severity of COVID-19 is higher among patients with cardiovascular risk factors. Despite the expression of angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 infection, in cardiomyocytes, there has been no conclusive evidence of direct viral infection although the presence of viral genome within COVID-19 patients' hearts has been reported. Here, we overexpressed SARS-CoV-2 genes in A549 lung epithelial cells. We then isolated extracellular vesicles (EVs) and detected the presence of viral RNA within these EVs. We observed that human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are receptive to these EVs, and viral genes were detectable in the cardiomyocytes. Accordingly, the uptake of viral RNA-harboring EVs led to an upregulation of inflammation-related genes in hiPSC-CMs. Thus, our findings indicate that SARS-CoV-2 RNA containing EVs represents an indirect route of viral RNA entry into cardiomyocytes.