Prebiotics Ameliorate Olanzapine-induced Gut Microbiota And Lipidemia Disturbance In Mice Mediated By PGRMC1-Wnt Signaling Pathway

Background:Olanzapine(OLZ)is considered one of the most effective secondgeneration antipsychotics.However,the therapeutic benefits associated with OLZ are limited to some extent by metabolic side effects,such as weight gain,dyslipidemia,etc.,which may further lead to cardiovascular disease,stroke,and premature death.Although various related mechanisms of OLZ-induced lipid metabolism disturbance have been proposed,such as the effect on metabolic hormone signaling and so on.But recent evidence points to the importance of the gut microbiome in this process.The latest literature reports that prebiotics,an adjuvant drug related to intestinal flora,can improve lipid metabolism disorders caused by OLZ,but the specific mechanism has not been clearly explored.The Wnt/β-catenin signaling pathway is a key signaling pathway that regulates hepatic lipid metabolism.Based on the previous research group and the latest literature survey,there is no research to explore the mechanism of PGRMC1-Wnt signaling pathway in OLZ-induced lipid metabolism disorder.Objective:1.To explore whether prebiotics improve olanzapine-induced metabolic disorders through PGRMC1-Wnt3a/β-catenin/PPAR-γ pathway.2.To further verify the key role of intestinal flora in the abovementioned adverse effects induced by OLZ.Methods:1.To explore the dosage of prebiotics and their effects on OLZinduced metabolic disorders.The mice were divided into five groups: the control group(Con),olanzapine group(OLZ),low-dose prebiotic group(LB-GOS),Medium-dose prebiotic group(MB-GOS),high-dose prebiotic group(HB-GOS);Prebiotics were administered by gavage,while blank solvent and OLZ were intraperitoneally injected continuously for 8 weeks;2.The body weight and food intake of mice were recorded every day during the administration period;H&E staining and Oil Red O staining were used to detect the liver tissue morphology of the mice;Biochemical detection kits were used to determine the level of lipid metabolism in mouse liver and plasma;High-throughput sequencing was used to determine mouse gut microbiota level;3.The UPLC-MS/MS was used to detect short chain fatty acids(SCFA)levels in mice plasma;Western blot was utilized to evaluate the protein expression of PGRMC1-Wnt3a/β-catenin/PPAR-γ pathway in mice liver.Results:1.Biochemical indicators of lipid metabolism: compared with OLZ group,the triacylglycerols(TG)levels in the OLZ+LB-GOS(p<0.05),and OLZ+HB-GOS group was significantly reduced(p<0.01).B-GOS had a certain reducing effect on total-cholesterol(TC)levels,but there was no significant difference.No significant differences were observed in liver lipid levels.2.Histochemical results: H&E staining in liver showed that the liver tissue of mice was abnormally morphologically damaged in OLZ and OLZ+LB-GOS groups,while liver tissue in the OLZ+HB-GOS group and Con group showed normal liver tissue morphology without obvious damage;Oil red O staining results showed that obvious lipid accumulation was observed in the OLZ group,compared with the Con group;Compare to the OLZ group,the red fat staining in the groups that OLZ combined with different doses of B-GOS showed a downward trend,but there was no statistical significance.3.Changes in intestinal flora: At the phylum level,the relative abundances of Firmicutes and Epsilonbacteraeota decreased in the OLZ group,compared with the Con group,while the Bacteroidetes,Actinobacteria and Proteobacteria increased.Compared with OLZ group,the Bacteroidetes levels increased and Firmicutes levels decreased after BGOS intervention;the proportion of Verrucomicrobia was significantly increased,and the proportion of Proteobacteria was decreased in both OLZ+LB-GOS and OLZ+HB-GOS group.At the genus level,the relative abundances of Facealibaculum,unclassified Muribaculaceae in the OLZ group were significantly increased,compared to the control group,whereas the proportions of Akkermansia and Bacteroides were significantly decreased.After administration of B-GOS,the disturbance of gut microbiota in mice was effectively alleviated,and the relative abundance of bacteria was reduced in the OLZ group.Furthermore,the OLZ+HBGOS group significantly increased the relative abundance of Akkermansia and Bacteroides compared with the OLZ group.4.Protein expression in liver: Compared with the OLZ group,the protein expression of PGRMC1,Wnt3 a,β-catenin and PPAR-γ were significantly up-regulated in OLZ+HB-GOS group(p<0.01),but the level of GPR43(G protein coupled receptor 43)was not statistically significant.GPR43 is one of the important receptors of SCFA.The results of our determination of SCFA in plasma showed that,compared with the OLZ group,after the intervention of B-GOS,there was no significant difference in the level of SCFA in the low,medium and high dose B-GOS groups(p>0.05).Conclusion:1.Long-term administration of OLZ(8 mg/kg/day)will cause hepatic lipid metabolism disorders in mice;2.Prebiotics can significantly improve the disturbance of gut microbiota caused by OLZ;3.The improvement of OLZ-induced hepatic lipid metabolism disorder by prebiotics may be mediated through the PGRMC1-Wnt3a/β-catenin/PPAR-γ pathway.