RNASE1 and endothelial dysfunction: In this study, we found that OMVs from the gram-negative bacteria Escherichia coli, Klebsiella pneumoniae and Salmonella enterica serovar Typhimurium repress endothelial RNase1 via an LPS-induced TLR4-IRAK-1 and p38-mediated mechanism to promote EC inflammation that favors development of endothelial dysfunction independent of the investigated donor bacteria.