Fig. 1

Detection of SARS-CoV-2 synthetic viral RNA fragments in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and endothelial cells (hiPSC-ECs) treated with EVs. a Schematic depiction of study design. Nsp1, non-structural protein 1; Nsp12, non-structural protein 12; E, envelope protein; N, nucleocapsid protein. b Expression of SARS-Cov-2 genes in A549 lung epithelial cells. A549 cells were infected with indicated lentiviral particles for 48 h and mRNA levels were measured by qRT-PCR (n = 3, mean ± S.D). ***P < 0.001 versus pLVX-Blank (Student’s t test). c Immunoblotting of EV markers demonstrating enrichment in the EV fraction compared to the supernatant. d SARS-CoV-2 genetic materials (Nsp1, Nsp12, E, and N) were detected in EVs secreted from A549 lung epithelial cells. EVs were purified from A549 cell culture media, and mRNA levels were measured by qRT-PCR (n = 3, mean ± S.D.). *P < 0.05; **P < 0.01; ***P < 0.001 versus pLVX-Blank (Student’s t test). e Uptake of ExoGlow-labeled EVs (pseudocolored red) or PBS (negative control) by hiPSC-CMs stained with cardiac troponin T (green) was visualized by confocal imaging. Scale bar = 10 μM. Small arrows depict detected EVs within cells. f qRT-PCR was performed to detect the presence of viral genes in hiPSC-CMs following EV uptake. (n = 3, mean ± S.D.). ***P < 0.001 versus EV-Blank (Student’s t test). g qRT-PCR was performed to detect the presence of viral genes Nsp1 and Nsp12 in hiPSC-ECs following EV uptake (n = 3, mean ± S.D.). ***P < 0.001 versus EV-Blank (Student’s t test). h Expression of inflammatory genes in hiPSC-CMs. hiPSC-CMs were treated with EVs released by A549 cells transduced with pLVX-Blank or pLVX-Nsp1 lentiviral particles for 6 h and mRNA levels were measured by qRT-PCR (n = 3, mean ± S.D.). Tumor necrosis factor-α (TNF-α, 50 ng/ml) was used as a positive control. *** P < 0.001 (one-way ANOVA followed by Tukey’s multiple comparisons test). IL1β, interleukin 1β; IL6, interleukin 6; MCP1, monocyte chemoattractant protein 1