Scutellarin is associated with reduced Ischemia-related inflammation and changes in miR-124-5p, AKR1B1 and miR-155: a potential mechanistic model

Objective This study investigated whether scutellarin can modulate inflammation-associated responses after cerebral ischemic injury in association with a potential miR-124– Akr1b1 regulatory relationship, together with parallel regulation of the pro-inflammatory miR-155. Methods Twenty-seven Kunming mice were allocated into sham operation (Sham), middle cerebral artery occlusion (MCAO), and scutellarin-treated MCAO (MCAO+Scu) groups. The MCAO+Scu group received intraperitoneal scutellarin (100 mg/kg, every 12 h for 3 days) after surgery. Cerebral infarct area was measured by TTC staining, protein levels of NLRP3, ASC, Caspase-1, TNF-α and IL-1β by Western blotting, and miR-124 and miR-155 levels by qPCR. In parallel, an oxygen-glucose deprivation (OGD) model was established in BV2 microglial cells, and cells were transfected with miR-124 or miR-155 mimics or inhibitors. Cellular metabolic activity was assessed by CCK-8, and the relevant miRNAs and proteins were measured by qPCR and Western blotting. Key targets were screened from the GeneCards and GEO databases, and molecular docking and miRNA target prediction were performed. The predicted miR-124-5p binding site in the Akr1b1 3′UTR was further validated by a WT/MUT dual-luciferase reporter assay in HEK293T cells. Results Compared with the Sham group, the MCAO group had a larger infarct area, higher NLRP3, ASC, Caspase-1, TNF-α and IL-1β protein levels, lower miR-124 and higher miR-155 (all P<0.05). Scutellarin treatment reversed these changes, and similar trends were observed in the OGD model. Network pharmacology identified Akr1b1 as a candidate key target. The miR-124-5p mimic significantly reduced luciferase activity of the Akr1b1 3′UTR-WT reporter but had no significant effect on the mutant reporter, supporting direct targeting of the predicted Akr1b1 3′UTR site by miR-124-5p. Scutellarin lowered Akr1b1 protein expression, and miR-124 mimic further suppressed Akr1b1 whereas miR-124 inhibition increased it. miR-155 manipulation did not measurably alter Akr1b1 protein levels. Conclusion Scutellarin attenuated ischemia-associated inflammatory responses and was accompanied by increased miR-124-5p, reduced Akr1b1 protein abundance, and reduced expression of NLRP3 inflammasome-associated proteins. The dual-luciferase assay supports Akr1b1 as a direct target of miR-124-5p.