Electroacupuncture-mediated lncRNA TUG1 regulates the miR-127-3p/NF-κB p65 axis to inhibit IBS-D low-grade intestinal inflammation

Abstract

Background Electroacupuncture (EA) demonstrates efficacy in alleviating diarrhea-predominant irritable bowel syndrome (IBS-D), yet its mechanisms concerning low-grade intestinal inflammation remain insufficiently elucidated. This study investigated whether EA ameliorates IBS-D symptoms by modulating the long non-coding RNA Taurine Upregulated Gene 1 (lncRNA TUG1)/microRNA-127 -3p (miR-127-3p)/nuclear factor-kappa B p65 (NF-κB p65) axis. Methods An IBS-D rat model was established using maternal separation, acetic acid enema, and chronic restraint stress. Rats were randomly allocated into control, model, EA (at ST-25 and ST-37), drug (rifaximin), and PDTC (NF-κB p65 inhibitor) groups. Behavioral assessments (body weight, loose stool rate, abdominal withdrawal reflex) were conducted. Molecular analyses included dual-luciferase reporter assays, RT-qPCR, western blot, ELISA, and immunofluorescence to evaluate the TUG1/miR-127-3p/NF-κB p65 axis, inflammatory factors (TNF-α, NLRP3, IL-6), and tight junction proteins (occludin, claudin-1, ZO-1). Intestinal ultrastructure was examined by electron microscopy. Results EA significantly improved general status, reduced diarrhea and visceral hypersensitivity in IBS-D rats, comparable to rifaximin and PDTC. Mechanistically, EA upregulated colonic lncRNA TUG1 expression, which sequesters miR-127-3p and partially derepresses NF-κB negative regulators (IκBα, A20), consistent with attenuated NF-κB pathway activation. This was associated with downregulated downstream pro-inflammatory mediators (NF-κB p65, TNF-α, NLRP3, IL-6) in serum and colon tissues. Furthermore, EA restored intestinal barrier integrity, as evidenced by improved mucosal ultrastructure and increased expression of tight junction proteins. Conclusion EA alleviates low-grade intestinal inflammation and visceral hypersensitivity in IBS-D rats. The therapeutic effect is mediated, at least in part through upregulation of lncRNA TUG1, which sponges miR-127-3p to inhibit the NF-κB p65 signaling pathway, thereby reducing inflammatory cytokine release and repairing the intestinal epithelial barrier. These findings suggest the TUG1/miR-127/NF-κB axis as a candidate therapeutic target for EA in IBS-D.