Frontiers in immunology
Fresh ginseng-derived vesicle-like nanoparticles protect against intestinal barrier injury in inflammatory bowel disease via the miR-29a-5p/TLR4 axis
By Tang X, Ren Y, He M and 5 others.
Abstract
Background
Inflammatory bowel disease (IBD) remains therapeutically challenging, and disruption of the intestinal epithelial barrier constitutes a key pathogenic event. Ginseng-derived vesicle-like nanoparticles (GDNPs) protect against intestinal barrier injury in IBD; however, the effects of ginseng processing on nanoparticle characteristics and biological activity remain insufficiently understood.
Methods
The protective effect of fresh and dried ginseng extract were compared in IBD model. GDNPs were isolated from fresh and dried ginseng by differential centrifugation and sucrose density-gradient ultracentrifugation, and characterized for morphology, particle size, and relative purity. Their effects on intestinal epithelial cell viability and permeability were compared. In vitro, inflamed NCM460 and RAW264.7 cells were treated with fresh GDNPs; tight junction protein expression and TLR4/STAT3 signaling were assessed by western blotting, and cytokine and miRNA (miR-29a-5p, miR-125b-5p, miR-21-5p) levels were measured by RT-qPCR. Trans-epithelial electrical resistance (TEER) was measured in epithelial cells overexpressing miR-29a-5p, and tight junction protein and TLR4 expression were examined after miR-29a-5p knockdown; direct targeting of TLR4 by miR-29a-5p was confirmed by dual-luciferase reporter assay. Intestinal epithelial cells were also exposed to conditioned medium from fresh GDNP-treated macrophages to assess tight junction protein and miR-29a-5p expression. In vivo, a dextran sulfate sodium (DSS)-induced murine colitis model was used to evaluate the preventive protective effects of low- or high-dose fresh GDNPs, and body weight, disease activity index (DAI), colon length, histopathology, macrophage polarization, tight junction protein expression, and inflammatory cytokine and miR-29a-5p levels were evaluated.