Inhibition of miR-155 alleviates sepsis-induced inflammation and intestinal barrier dysfunction by inactivating NF-κB signaling

• Published in: International immunopharmacology Vol. 90; p. 107218
• Main Authors: Cao, Ying-Ya, Wang, Zhen, Wang, Zhong-Han, Jiang, Xiao-Gan, Lu, Wei-Hua
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2021; Elsevier BV
• Subjects: Animal models; Animals; Anti-Inflammatory Agents - pharmacology; Cell Line; Cell permeability; Cytokines; Cytokines - metabolism; Deactivation; Dextran; Dextrans; Disease Models, Animal; Enzyme-linked immunosorbent assay; Evaluation; Gene expression; Humans; Inflammation; Inflammation - drug therapy; Inflammation - genetics; Inflammation - metabolism; Inflammation - microbiology; Inflammation Mediators - metabolism; Inhibitors; Interleukin 6; Intestinal Absorption - drug effects; Intestinal barrier; Intestinal Mucosa - drug effects; Intestinal Mucosa - metabolism; Intestinal Mucosa - microbiology; Intestine; Lipopolysaccharides; Localization; Male; Mice; Mice, Inbred C57BL; microRNA-155; MicroRNAs - antagonists & inhibitors; MicroRNAs - genetics; MicroRNAs - metabolism; miRNA; NF-kappa B - metabolism; NF-κB protein; Nuclear factor-κB; Permeability; Polymerase chain reaction; Protein expression; Proteins; Regulatory mechanisms (biology); Sepsis; Sepsis - drug therapy; Sepsis - genetics; Sepsis - metabolism; Sepsis - microbiology; Signal Transduction; Signaling; Tight Junction Proteins - metabolism; Tight Junctions - drug effects; Tight Junctions - metabolism; Tight Junctions - microbiology; Transfection; Tumor necrosis factor-α; Western blotting; Zonula occludens-1 protein; microRNA-155; Intestinal barrier; Sepsis; Inflammation; Nuclear factor-κB
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2020.107218

•Sepsis elevated the level of miR-155 in vivo and in vitro.•miR-155 regulated the activity of the NF-κB pathway in intestinal epithelium.•miR-155 inhibitor eased inflammation and intestinal barrier injury via NF-κB signal. MicroRNA-155 (miR-155) is implicated in the pathological processes of sepsis. However, the function and regulatory mechanism of miR-155 in sepsis-induced inflammation and intestinal barrier dysfunction remain unknown. In this study, mouse models of sepsis were established by caecal ligation and puncture (CLP). To reduce miR-155 expression, the mice were injected for three consecutive days with an miR-155 inhibitor (80 mg/kg) before CLP. The serum DAO concentration was measured by ELISA, and histological changes in the intestine were identified by H&E staining 24 h after CLP. FITC-dextran assays were used to evaluate intestinal permeability. MiR-155 gene expression was evaluated with RT-PCR, and relative protein expression was assessed by Western blotting. NCM460 cells were transfected with an miR-155 mimic/miR-155 inhibitor or pretreated with an NF-κB inhibitor before LPS treatment, and the cytokines levels, miR-155 gene expression and relative protein expression were measured. Sepsis increased miR-155, DAO and FITC-dextran levels and reduced Occludin and ZO-1 expression. Mice injected with the miR-155 inhibitor recovered from the damages. Transfection of NCM460 cells with the miR-155 mimic elevated the NF-κB (P65) and p-NF-κB (p-P65) localization and expression in the nucleus, which was reversed by the miR-155 inhibitor. Pretreatment with an NF-κB inhibitor suppressed inflammation, improved cell permeability to FITC-dextran and increased Occludin and ZO-1 levels. Transfection with the miR-155 inhibitor decreased TNF-α and IL-6 levels, reduced cell permeability to FITC-dextran and increased ZO-1 and Occludin expression. The effects induced by transfection with the miR-155 mimic, including elevated TNF-α and IL-6 levels, hyperpermeability to FITC-dextran and reduced ZO-1 and Occludin expression, were partly rescued by pretreatment with the NF-κB inhibitor. These findings reveal that the miR-155 inhibitor alleviates inflammation and intestinal barrier dysfunction by inactivating NF-κB signaling during sepsis.