Early Metabolomics Changes And Possible Metabolic Pathways In Rats With Different Severity Of Sepsis

Purpose : In this study,early metabolomics changes in septic rats of varying severity were examined,and differential metabolites associated with sepsis rats were screened to explore possible metabolic pathways.Method : The septic rat model of different severity was established mainly by cecal ligation and puncture(CLP).In the early stage,we observed the mortality of septic rats by pre-experiment,and collected HE staining to observe the pathological changes of different tissue samples.In this study,septic rats were subjected to cardiac blood sampling at 6 hours and 24 hours,respectively,combined with ultra performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry(UHPLC-Q-TOFMS/MS),The serum metabolomics analysis was carried out,and then the data rows were preprocessed.The normalized data matrices were all imported into SIMCA-P+14.1 software package for multivariate analysis of the obtained data matrix,statistical calculations were performed using SPSS,and the statistical significance of the mean was tested by Student's t test(p<0.05).The VIPs sequence was generated by multivariate statistical analysis.The variable impact of the project score(VIP> 1.0)identified significant changes in metabolites,the use of the HMDB database to identify metabolites,and finally the MetaboAnalyst website for metabolic pathway analysis.Result: 1.The septic rat model established by CLP observed that themorphological changes(such as decreased activity,decreased vigilance,slow response,etc.)in rats with severe sepsis were more obvious than those in mild sepsis rats.The mortality rate was also much higher than that in mild sepsis rats.HE staining pathological sections of liver,kidney and lung between groups of mild and severe sepsis showed different degrees of damage under the microscope(such as structural disorders,inflammatory cell infiltration,etc.),the above results suggest successful modeling.2.The results of serum metabolites taken at 6 hours and 12 hours in rats with severe sepsis showed significant metabolic differences between the control group and the sham operation group.The metabolic expression of the sham operation group and the septic rats were different.However,there was no significant difference in the metabolic profile between mild and severe sepsis rats.3.In the 6-hour postoperative serum metabolite assay,there were6 differential metabolites in the mild sepsis rats compared with the sham-operated group,namely: 3-hydroxyhippuric acid,creatinine,farnes yl pyrophosphate,glucose-6-phosphate,glycerol 3-phosphate,pyridoxal5-phosphate.There are 8 differential metabolites in rats with severe se psis,namely:3-hydroxyhippuric acid,9,10-epoxyoctadecenoic acid,beta-Alanine,creatinine,L-palmitoylcarni-tine,glucose-6-phosphate,glycerol3-phosphate,Pyridoxal 5-phosphate.There are four differential metabo lites between mild and severe sepsis rats:25-hydroxyvitamin D2,3?,7?-dihydroxyprostanoic acid,glycyrrhetinic acid,and valanic acid.In the12-hour postoperative serum metabolite assay,there were 12 differentia l metabolites in mild sepsis rats compared with the sham-oper-ated gr oup:2-Furoylglycine,adenine,Aminoadipic acid,D-alpha-Aminobutyric acid,D-Galactose,Farnesyl pyrophosphate,glucose-6-phosphate,homocy steine,L-2-hydroxyglutaricacid,pyridoxal 5-phosphate,urea,Lyso-PC(18:2(9Z,12Z)).There are six differential metabolites in severe sepsis rats:2-Furoylglycine,adenine,D-alpha-Aminobutyric acid,homocysteine,pyridoxal 5-phosphate,and urea.There are 4 differential metabolites between mild and severe sepsis rats,namely:25-hydroxyvitamin D2,3?,7?-dihydroxyprostanoic acid,glycyrrhe-tinic acid,L-2-hydroxyglutaric acid.4.Differential metabolites of the 6-hour and 12-hour groups in rats with mild and severe sepsis were analyzed by metabolic pathways,and the results were all related to the vitamin B6 metabolic pathway,but 6 hours and 12 hours.The differential metabolites between the light and heavy of the two time periods did not find a clearly related metabolic pathway.Conclusion: Through this study,it was found that in the rat sepsis model;the differences in metabolites were different between different severity and time points.Through the analysis of differential metabolites,it is found that most of the metabolic pathways involved are related to amino acid metabolism,glycolysis and lipolysis.