Healthy serum sEVs protect against acute pancreatitis-induced intestinal barrier dysfunction via miR-579-3p/ANXA3/NLRP3 axis

Acute pancreatitis (AP) frequently leads to severe complications, including intestinal barrier dysfunction, which significantly impacts patient prognosis. This dysfunction is characterized by increased permeability and systemic inflammation, yet the precise molecular mechanisms driving it remain poorly understood. Current standard-of-care primarily focuses on supportive measures, often failing to directly address the underlying gut pathology. This study investigates the therapeutic potential of small extracellular vesicles (sEVs) and their microRNA cargo in modulating pyroptosis, a highly inflammatory form of programmed cell death, specifically focusing on the NLRP3 inflammasome pathway, which is implicated in various inflammatory diseases.

Researchers isolated sEV-enriched preparations from 10 AP patients (AP-sEV) and 10 healthy controls (HC-sEV) using ExoQuick precipitation followed by ultracentrifugation. A murine model of AP was established using cerulein and lipopolysaccharide (LPS) to induce disease. For in vitro studies, human intestinal epithelial cells were stimulated with LPS. The study compared the effects of HC-sEV and AP-sEV preparations on AP-induced tissue damage, intestinal permeability, tight junction protein expression (claudin-1, occludin, ZO-1), inflammatory cytokine levels (TNF-α, IL-6, IL-1β), and pyroptosis-related protein expression (NLRP3, gasdermin D, cleaved caspase-1). Bioinformatics analysis identified differentially expressed microRNAs, with miR-579-3p further investigated for its role.

HC-sEV preparations significantly ameliorated AP-induced tissue damage in the murine model. They restored tight junction proteins (claudin-1, occludin, ZO-1), leading to reduced intestinal permeability. Furthermore, HC-sEVs suppressed inflammatory cytokines, including TNF-α, IL-6, and IL-1β, and key pyroptosis-related proteins such as NLRP3, gasdermin D, and cleaved caspase-1. Conversely, AP-sEV preparations exacerbated intestinal barrier dysfunction, highlighting a potential pathogenic role. Bioinformatics analysis revealed that miR-579-3p was significantly downregulated in AP-sEVs compared to HC-sEVs. Functional studies demonstrated that inhibition of miR-579-3p reversed the protective effects observed with HC-sEVs, indicating its crucial role. > ANXA3 was subsequently validated as a direct target of miR-579-3p, and its overexpression counteracted the miR-579-3p-mediated protection, confirming the miR-579-3p/ANXA3 axis in regulating NLRP3 inflammasome-mediated pyroptosis.