瑞马唑仑调控巨噬细胞M2极化修复紧密连接蛋白而减轻创伤性颅脑损伤小鼠肠道屏障功能障碍及代谢紊乱OA

Objective Traumatic brain injury(TBI)can lead to intestinal barrier disruption and metabolic disorder.Remimazolam(Remi)possesses certain anti-inflammatory and organ-protective effects.This study aims to determine the effects of Remi on intestinal barrier function and intestinal metabolism in TBI mice and explore its potential protective mechanisms.Methods A total of 120 male C57BL/6 mice(8 to 12 weeks old,weighing 18 to 20 g)were randomly divided into the Sham group(craniotomy only),the TBI group(established using controlled cortical impact),and the TBI+Remi group(intraperitoneal administration of 10 mg/kg Remi 2 h before modelling),with 40 mice in each group.Intestinal tissue samples were collected 24 h after modeling.Histopathological changes in ileal tissues were observed by HE staining,and the degree of ileal injury was semi-quantitatively assessed using the Chiu's scoring system.Transmission electron microscopy was used to observe the ultrastructure of ileal epithelial cells,and Evans blue(EB)staining was employed to assess intestinal permeability.Western blotting was performed to detect the expression levels of tight junction proteins[Occludin and zonula occludens-1(ZO-1)].ELISA was applied to measure the levels of intestinal barrier function-related and mucosal immune-related indicators,including diamine oxidase(DAO),D-lactate dehydrogenase(D-LDH),and secretory immunoglobulin A(sIgA).The expression levels of inducible nitric oxide synthase(iNOS)and cluster of differentiation 206(CD206)were detected by Western blotting and immunofluorescence assay.Untargeted metabolomics was conducted to analyze intestinal metabolic changes,followed by differential metabolite screening and KEGG pathway enrichment analysis.Results Compared with the Sham group,the TBI group showed significantly damaged ileal mucosa and ultrastructure,with increased Chiu's score,intestinal permeability,and levels of DAO,D-LDH,and sIgA,as well as decreased expression of Occludin and ZO-1(P<0.05).Remi treatment resulted in significant improvements in all the above changes compared with the condition in the TBI group(P<0.05).Increased iNOS expression and decreased CD206 expression were observed in the TBI group compared to the Sham group,while Remi treatment reversed the changes induced by TBI modeling(P<0.05).Untargeted metabolomics identified 2 567 metabolites,and compared with the Sham group,851 differential metabolites were found in the TBI group,including 260 upregulated and 591 downregulated metabolites,mainly involved in amino acid metabolism,unsaturated fatty acid and bile acid metabolism,glucose metabolism,and nucleotide metabolism pathways.The relative abundance of citrulline and tyrosine was decreased in the TBI group,whereas 5-aminolevulinic acid(5-ALA)and the endogenous prostaglandin E2 metabolite 15-keto-prostaglandin E2(15-keto-PGE2)were increased.Compared with the TBI group,the TBI+Remi group showed increased relative abundance of citrulline and tyrosine and decreased relative abundance of 5-ALA and 15-keto-PGE2(P<0.05).Conclusion Remi alleviates intestinal mucosal and epithelial ultrastructural damage,enhances tight junction protein expression,and reduces intestinal permeability in TBI mice,and partially ameliorates TBI-induced intestinal metabolic disturbances.