Fig. 2

Effects of SNCA silencing in SARS-CoV-2 replication in A549-hACE2 epithelial lung cells. A Transcriptional analysis assessing the efficacy of SNCA silencing within A549-hACE2 cells, and related effects in SARS-CoV-2 infection (MOI 0.05) through assessment of intracellular N gene expression. Results are shown as mean ± SEM from n = 3 independent experiments. Values for SNCA and SARS-CoV-2 N mRNA were analyzed by applying One-Way ANOVA followed by multiple testing correction. **p < 0.01, ***p < 0.001, ****p < 0.0001. NE = not expressed. B1 Representative immunofluorescence experiments showing SNCA-siRNA efficacy at protein levels, and related effects in SARS-CoV-2 infection (MOI 0.05) through intracellular N protein staining. Cells were fixed in 4% Formaldehyde solution for 15 min and permeabilized with 0.1% of Triton X-100 for 15 min. Bars correspond to 20 μm. B2 Percentage of N-positive cells ± SD calculated as the number of N-positive cells/total cells per microscopic field, from n = 9 microscopic fields per experimental group, from n = 3 independent experiments. Data were analyzed by applying the Student’s t-test for comparison between NT-siRNA and SNCA-siRNA groups. ns = non-significant. C Quantification of viral replication from cell supernatants through RT-qPCR for the SARS-CoV-2 N gene at 24 and 48 h post-infection in A549-hACE2 cells treated with SNCA-siRNA compared with NT-siRNA. Results are shown as mean ± SEM from n = 5 independent experiments. Values for 24 and 48 h post-infection were analyzed by applying One-way ANOVA. **p < 0.01, ***p < 0.001