Acute respiratory distress syndrome (ARDS) is a critical condition with high mortality.
HMGB1 (high-mobility group
protein B1) is one of the key proinflammatory factors in the ARDS "inflammatory storm." According to previous studies, some
microRNAs (
miRNAs) play important roles in this process. We aimed to determine the contributing
miRNAs targeting the expression and release of
HMGB1.
miRNA expression in the peripheral blood of patients with ARDS was measured by
miRNA microarray.
miRNAs targeting
HMGB1 were screened and explored for further study. In LPS-induced cell and mouse ARDS models, we explored the effect of this
miRNA on the expression and secretion of
HMGB1 by Western blot, real-time qPCR, and ELISA. The effects of this
miRNA on the NF-κB signaling pathway, proinflammatory
cytokines, and NLRP3 (
nod-like receptor protein 3)
inflammasome were detected by Western blot and real-time qPCR. In ARDS models, microRNA-574-5p (miR-574-5p) expression could be induced by the TLR4/NF-κB pathway upon LPS stimulation. It could suppress the inflammatory response by targeting
HMGB1. Enforcing the expression of miR-574-5p or
HMGB1 siRNA silencing inhibits the activation of NF-κB signaling pathway and the NLRP3
inflammasome. Moreover, overexpression of
HMGB1 reversed the antiinflammatory effect of miR-574-5p. In ARDS mice, overexpression of miR-574-5p suppresses alveolar leukocytes infiltration, interstitial
edema,
protein effusion, and
inflammation. This study demonstrated that miR-574-5p provided negative feedback to LPS-induced
inflammation and relieved ARDS. It may provide new therapeutic strategies for ARDS.