Expression Profile Analysis And Experimental Validation Of Hub Genes Associated With Sepsis-induced Cardiac Dysfunction

ObjectivesCardiac dysfunction is a serious complication associated with mortality in patients with sepsis,causing its mortality to soar.In this study,we used bioinformatic analysis to identify key pathogenic genes involved in sepsis-induced cardiac dysfunction and potential molecular mechanisms,relevant experiments to confirme the results of bioinformatics analysis.MethodsPart 1: Three microarray data of sepsis cardiac dysfunction were screened from the GEO public database.The Robust Rank Aggreg algorithm was used to eliminate the batch effect,and differential expressed genes(DEGs)analysis was carried out to obtain 198 DEGs.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways to find out the signaling pathways related to sepsis cardiac dysfunction,in addition to the construction of protein-protein interaction(PPI)networks of the DEGs using the STRING database,and core differential genes were found by MCODE plug-in.Part 2: 48 Clean adult male C57BL/6 mice were randomly divided into 4groups,namely the lipopolysaccharide group(LPS)group n = 16,normal saline group(NS)group n = 8,the cecal ligation and perforation group(CLP)group n =16,sham operation group(Sham)group n = 8.After 24 hours,cardiac function of mice was detected by echocardiography,m RNA expression level of inflammatory factor and core differential genes in cardiac tissue was detected by Quantitative Real-time PCR,Masson staining and HE staining was used to observe the morphological changes of heart tissue.ResultsPart 1: The results of Bioinformatics analysis: A total of 198 DEGs were identified using the three GEO datasets that were publicly available,of which,136 genes were upregulated and 62 genes were downregulated.GO and KEGG analysis demonstrated that the DEGs were enriched for biological functions of chemokine activity,chemokine receptor binding,Toll-like receptor binding,immunoglobulin binding,and extracellular matrix structural constituents and so on.Eleven of the most closely related genes among the DEGs were identified using the PPI network,they were Il6,Itgam,Cxcl10,Tlr2,Ccl2,Timp1,Icam1,Cxcl1,Cxcl2,Ccl5 and Hmox1.Part 2:1.Compared with the control group,the heart rate,LV Vol and LVID of sepsis model mice were significantly decreased(P<0.05),the LVAW and LVPW were significantly thicker(P< 0.05).2.Compared with the control group,the expression levels of IL6,IL-1β and TNF-α in the blood of CLP model sepsis mice were significantly increased(P<0.05).The expression levels of inflammatory factors IL-1β and TNF-α in LPS model sepsis mice significantly increased(P <0.05),the expression level of inflammatory factor IL6 increased with no difference(P>0.05).3.Compared with the control group,the expression levels of Cxcl1,Cxcl10,Timp1,Il6 and Tlr2 were significantly increased in CLP sepsis mice(P<0.05),while the expression levels of Itgam,Cxcl2,Ccl2,Homx1,Ccl5 and Icam1 have no difference(P> 0.05).The expression levels of Ccl2,Ccl5,Cxcl1,Cxcl10,Icam1,Itgam and Tlr2 were significantly increased in LPS induced sepsis mice(P<0.05),while the expression levels of Il6,Cxcl2,Homx1 and Timp1 have no difference(P>0.05).4.Compared with the control group,the myocardial fibers were obviously edema,interstitial exudation and infiltration of inflammatory cells can be seen,and the structural arrangement is disordered.Fibrotic changes are found in myocardial tissue.ConclusionWe have identified 11 core genes that may be involved in the progression of sepsis-induced myocardial injury.The reliability of our results was validated through a number of experimental techniques.Our study demonstrated that genes such as Il6,Itgam,Cxcl10,Tlr2,Ccl2,Timp1,Icam1,Cxcl1,Cxcl2,Ccl5 and Hmox1 may be involved in the development of sepsis cardiac dysfunction.