Chronic inflammatory lung diseases accompanied by Gram-negative bacteria infection are characterized by excessive mucin production. Lipopolysaccharide (LPS), the major endotoxin released from Gram-negative bacteria, is a potent inflammatory agonist for mucin overproduction. In this study, we sought to examine whether the toll-like receptor (TLR)-responsive microRNA miR-155 plays a role in LPS-provoked induction of mucin 5AC (MUC5AC) and the potential role of suppressor of cytokine signaling 1 (SOCS1) involved in this process. We found that LPS increased the expression of MUC5AC in association with TLR4-dependent miR-155 induction. The suppression of miR-155 by antagomir led to an excessive production of SOCS1, thereby downregulation of MUC5AC production. Collectively, these data imply that miR-155 is involved in LPS-induced MUC5AC overproduction through a TLR4-dependent manner and thereby the downregulation of SOCS1.
Keywords: Lipopolysaccharide; MicroRNA-155; Mucin 5AC; Suppressor of cytokine signaling 1; Toll-like receptor 4.
Copyright © 2019. Published by Elsevier B.V.