Fig. 1

Validation of C1632 as a potential anti-SARS-CoV-2 drug that suppresses both virus replication and viral-induced inflammation by upregulating let-7. Let-7 inhibits exogenous expression of S protein (a) and M protein (b) in HEK293T cells. GFP was cloned into vector to ensure the equal transfection/expression efficiency. Scramble sequence was used as a control. c The expression level of IL-1β, IL-6, IL-8, CCL2, GM-CSF, TNF-α, and VEGFα were downregulated by overexpressed let-7a and let-7c in THP1 cells. d let-7-5p and let-7-3p sponges increased the expression level of multiple inflammatory factors in THP1 cells. let-7 stimulator C1632 inhibited exogenous expression of S (e) and M (f) protein in HEK293T cells in a concentration dependent manner. g–i The expression of IL-1β, IL-6, IL-8, CCL2, GM-CSF, and VEGFα were downregulated by C1632 in THP1 derived macrophages (g) and PBMCs (h). i The expression of IL-1β, IL-6, IL-8, CCL2, GM-CSF, TNF-α, and VEGFα were downregulated by C1632 in Huh-7 cells. The RNA level of N (j) and ORF1 (k) were suppressed by C1632 in a dosage dependent manner in SARS-CoV-2 infected Huh-7 cells. l C1632 treatment decreased S protein level in SARS-CoV-2 infected Huh-7 cells (western blot). The expression level of IL-6 (m), IL-8 (n), TNF-α (o) and CCL2 (p) were downregulated by C1632 in SARS-CoV-2 infected Huh-7 cells