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.

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.

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 2567 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).

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.

To observe the ameliorative effect of inhibiting acetyl-CoA carboxylase 2(ACC2) on cardiac dysfunction in septic mice and investigate its underlying mechanism.

Mouse model of sepsis was established by cecal ligation and perforation.A total of 24 male C57BL/6 mice (aged 8 weeks, weighing 20~25 g) were divided into sham operation group, sepsis group and ND-630+sepsis group.The cardiac specific ACC2 knockout (ACC2^ΔCM) mice were constructed by Cre-LoxP recombinase system, and ACC2^flox/flox Myh6-Cre^-(ACC2^fl/fl) mice were used as control.Several genetically engineered mice (8 weeks old, 20~25 g, male) were divided into ACC2^fl/fl+sham operation group, ACC2^fl/fl+sepsis group, ACC2^ΔCM+sepsis group, ACC2^ΔCM+Mal-CoA+sepsis group, and ACC2^ΔCM+sham operation group according to the random number table method.The contractile function and myofilament calcium sensitivity of cardiomyocytes were measured by a cell microtensiometer.Western blotting was used to detect the expression level of ACC2, and ELISA was employed to measure the level of malonyl-CoA (Mal-CoA) in myocardial tissue.The survival of the mice in 36 h after sepsis was observed.

Compared with the sham operation group, the contraction amplitude of cardiomyocytes in sepsis group was decreased markedly, and the calcium sensitivity decreased significantly as well (P < 0.05).Based on the ACC2^fl/fl+sham operation group, the ACC2^ΔCM+sepsis group showed significant improvement in myocardial contraction compared with the ACC2^fl/fl+sepsis group, with the contraction amplitude of cardiomyocytes recovered by 48.1%, and significantly restored calcium sensitivity (P < 0.05).ACC2^ΔCM+Mal-CoA+sepsis group showed a notable decrease in myocardial cell contraction amplitude and a significant decrease in calcium sensitivity when compared to the ACC2^ΔCM+sepsis group (P < 0.05).Compared with the sepsis group, the contraction amplitude of cardiomyocytes in the ND-630+sepsis group increased significantly, and the calcium sensitivity of myofilament also increased (P < 0.05).The expression level of ACC2 protein in the myocardial tissue of mice in the sepsis group increased compared to the sham operation group (P < 0.05).The level of myocardial Mal-CoA in the sepsis group was higher than that in the sham operation group (P < 0.05);Mal-CoA level in the myocardium of ACC2^ΔCM+sepsis group mice was lower than that of sepsis group (P < 0.05).The 36-hour survival rate of the ACC2^ΔCM+sepsis group.mice was 37.5% higher than that of the ACC2^fl/fl+sepsis group mice.(P < 0.05).

Inhibition of ACC2 exerts a protective effect on myocardial contractility and calcium sensitivity in septic mice by reducing Mal-CoA.

To investigate the protective effects of remimazolam (Remi), a novel benzodiazepine sedative, on intestinal barrier function in septic mice.

A mouse model of sepsis was established using cecal ligation and puncture (CLP). A total of 96 SPF-grade adult male C57BL/6 mice were randomized into sham operation (Sham), sepsis (Sepsis), and sepsis with Remi intervention (Sepsis+Remi) groups. Survival rate and survival time were recorded within 72 h after modeling. Intestinal pathological alterations, barrier functional indicators, ZO-1 expression, and macrophage polarization status were observed and detected to evaluate the effects of Remi. Lipopolysaccharide (LPS) was used to treat RAW264. 7 cells for 24 h to simulate in vitro sepsis model. The cells were divided into control (Control), LPS, and LPS+Remi groups. Immunofluorescence staining was performed to assess macrophage phenotype, mitochondrial morphology, and mitochondrial reactive oxygen species (MtROS), and Western blotting was applied to detect the protein expression of iNOS and CD206.

Compared with the sepsis group, Remi intervention significantly improved the survival rate of septic mice from 12. 50% to 68. 75% and markedly prolonged survival duration (P<0. 05). Histopathological analysis demonstrated partial restoration of intestinal villus architecture, accompanied with attenuated interstitial edema and reduced inflammatory cell infiltration after Remi intervention. Furthermore, the intervention group demonstrated significant improvement in functional indicators. Both in vivo and in vitro experiments demonstrated elevated iNOS and decreased CD206 expression in the septic mice and LPS-stimulated macrophages (P<0. 05), which were partially reversed after Remi intervention. Furthermore, LPS-stimulated macrophages exhibited fragmented mitochondria and elevated MtROS level, whereas Remi intervention ameliorated these conditions (P<0. 05).

Remi protects intestinal barrier function in septic mice by mitigating mitochondrial dynamics imbalance-induced oxidative damage and ameliorating inflammatory macrophage activation.