show Abstracthide AbstractSevere acute respiratory syndrome coronavirus (SARS-CoV) and the closely related SARS-CoV-2 are emergent highly pathogenic human respiratory viruses causing acute lethal disease associated with lung damage and dysregulated inflammatory responses. SARS-CoV envelope protein (E) is a virulence factor involved in the activation of various inflammatory pathways. Here, we study the contribution of host miRNAs to the virulence mediated by E protein. Small RNAseq analysis of infected mouse lungs identified miRNA-223 as a potential regulator of pulmonary inflammation, since it was significantly increased in SARS-CoV-WT virulent infection as compared to the attenuated SARS-CoV-?E infection. In vivo inhibition of miRNA-223-3p increased mRNA levels of pro-inflammatory cytokines and NLRP3 inflammasome, suggesting that during lung infection, miRNA-223 might contribute to restrict an excessive inflammatory response. Interestingly, miRNA-223-3p inhibition also increased the levels of the CFTR transporter, which is involved in edema resolution and was significantly downregulated in the lungs of mice infected with the virulent SARS-CoV-WT virus. At the histopathological level, a decrease in the pulmonary edema was observed when miR-223-3p was inhibited, suggesting that miRNA-223-3p was involved in the regulation of the SARS-CoV-induced inflammatory pathology. These results indicate that miRNA-223 participates in the regulation of E protein mediated- inflammatory response during SARS-CoV infection by targeting different host mRNAs involved in the pulmonary inflammation and identify miRNA-223 as a potential therapeutic target in SARS-CoV infection. Overall design: Standard RNA-seq (Illumina 100nt single-ends, strand-specific, total RNA) of two or three biological replicates per sample. Two time points (2dpi and 4dpi). Three infection types (infected with rSARS-CoV-deltaE, infected with rSARS-CoV wild type and Mock).