Figure 2
SARS-CoV-2 enters into ECs through endocytosis. (A) Representative electron microscopy images (× 80,000) for senescent HUVECs infected with SARS-CoV-2 at 50 MOI (2 hpi). Arrows indicate SARS-CoV-2 virions. Bars: 200 nm. (B) Representative electron microscopy images (× 80,000) for early passage and senescent ECs infected with SARS-CoV-2 at 1 MOI (6 hpi). Arrows indicate SARS-CoV-2 entry via caveolae-like structures. Bars: 200 nm. (C) Representative electron microscopy images (× 80,000) for early passage and senescent ECs infected with SARS-CoV-2 at 1 MOI (24 and 48 hpi). Arrows indicate SARS-CoV-2 virions. Bars: 200 nm. (D) Representative images of immunocytochemistry for SARS-CoV-2 spike protein (red fluorescence) and Rab5A (green fluorescence) in replicative senescent HUVECs infected with SARS-CoV-2 (50 MOI) at 6 hpi. SARS-CoV-2 spike proteins were largely co-localized with Rab5A. Bars: 100 μm. Spike and Rab5A double-positive areas were quantitatively analyzed (n = 6 each). Statistical analysis was performed using Mann Whitney U-test. Data are presented as mean ± SE **P < 0.01.
