Improvement of M1 Polarization and Gut Flora with MiR-124 Agonist in HAP Mice

Abstract

Background: Hyperlipidemic acute pancreatitis (HAP) is characterized by high triglyceride (TG) and acute pancreatitis (AP), and is closely related to intestinal microflora. MiR-124 was found to have a significant regulatory relationship with chronic pancreatitis. Here, the study aimed to investigate the protection effect of miR-124 agonist in HAP. Methods: HAP was induced in mice using a high-fat diet (HFD) and cerulein. We evaluated the biochemical and morphological protective effects of miR-124 in HAP mice. miR-124 expression in the serum and pancreas was quantified by real-time quantitative PCR (qRT-PCR). Cluster of differentiation 68 (CD68) expression in pancreatic macrophages was detected by immunohistochemistry. Colonic flora was analyzed using High-Throughput Sequencing. Flow cytometry was performed to determine macrophage polarization. Serum inflammatory cytokines were measured using enzyme-linked immunosorbent assay (ELISA). Western blot (WB) was performed to detect protein expression. Results: The results revealed that miR-124 expression was downregulated in HAP mice (p < 0.001), which exhibited pathological injury and inflammatory cell infiltration in the pancreas. However, this status was inhibited by miR-124 agonist treatment. High-throughput sequencing of 16S rDNA demonstrated that miR-124 agonist treatment significantly reversed HAP-induced gut dysbiosis. Using Linear discriminant analysis Effect Size (LEfSe) analysis, we found that Rikenellaceae was the key species in the miR-124 agonist treatment of HAP. Finally, we found that the treatment with the miR-124 agonist promoted macrophage polarization toward M2 (p < 0.05) and inhibited the inflammatory response (p < 0.05) in HAP mice. Conclusion: MiR-124 agonists improve HAP by attenuating inflammatory reactions, regulating macrophage polarization, and rebalancing the intestinal microbiota.