Journal: Frontiers in Cardiovascular Medicine
Article Title: SARS-CoV-2 infection of endothelial cells, dependent on flow-induced ACE2 expression, drives hypercytokinemia in a vascularized microphysiological system
doi: 10.3389/fcvm.2024.1360364
Figure Lengend Snippet: Upregulated ACE2 expression in the vascularized micro-organ supports SARS-CoV-2 pseudotyped infectivity. qPCR analysis of ( A ) ACE2, ( B ) AGTR1, and ( C ) TMPRSS2, which are necessary for SARS-CoV-2 infectivity, comparing monolayer normal human lung fibroblasts (NHLF), monolayer EC, the vascularized micro-organ (VMO) before (D4) and after (D8) the formation of perfusable vasculature. ( D ) Immunofluorescence staining of a D8 VMO showing CD31/PECAM1 (red), DAPI (blue), and localization of ACE2 (green) and TMPRSS2 (purple) to the endothelium. Showing nonspecificity of secondary antibodies alone. ( E ) Infectivity efficiency (mean fluorescent intensity) of SARS-CoV-2 pseudotyped virus compared to a lentivirus expressing green fluorescent protein (GFP). ( F ) Titering of GFP SARS-CoV-2 pseudotyped virus in a perfused VMO. Infectivity is measured as an increase in the mean fluorescent intensity of the GFP channel. ( G ) Subset of a D8 VMO EC (mCherry) and background fluorescence or fluorescence induced by infection with SARS-CoV-2 pseudotyped virus (GFP). Ctrl, control; PV, pseudotyped virus. ( H ) qPCR analysis of ACE2 expression induced by shear stress in an ibidi microfluidic chip. *<0.05, **<0.01, ***<0.001.
Article Snippet: Virus infectivity was determined by infecting 1 × 10 4 human ACE2 receptor expressing HEK 293 T target cells (BEI Resources) per well with a serial dilution of the CoV-2/HIV-1 pseudotyped virus particles.
Techniques: Expressing, Infection, Immunofluorescence, Staining, Virus, Fluorescence, Control, Shear