Identification And Validation Of Key Autophagy-Related Genes In Lupus Nephritis Based On Bioinformatics Analysis

BackgroundLupus nephritis(LN)is one of the most common and serious complications of SLE.Autophagy is a ubiquitous cellular biological process in eukaryotic cells.It is an important and highly conservative regulatory mechanism to maintain the homeostasis of the intracellular environment.Previous studies have shown that autophagy may be involved in the pathogenesis of LN,but its exact role in LN is unclear.However,there is no research on the pathogenesis of autophagy-related genes in LN based on bioinformatics analysis.ObjectiveThis study aims to use bioinformatics analysis to investigate the changes in gene expression in LN,analyze the key pathological processes and pathways that may lead to lupus nephritis,and identify key autophagy-related genes involved in the pathology of LN.Method1.The mRNA expression profile of GSE32591 was obtained from the GEO database,and the differentially expressed genes of LN were identified by R software in glomeruli and tubulointerstitium.Functional enrichment analysis of the differentially expressed genes were performed.2.The differentially expressed autophagy-related genes in glomeruli and tubulointerstitium were obtained by crossing the differentially expressed genes with autophagy-related genes,Functional enrichment analysis and protein-protein network interaction were performed.3.CIBERSORT algorithm was used to estimate the proportion of 22 kinds of immune cells in glomeruli and tubulointerstitium.We further explored the correlation between differential expression of autophagy-related genes and immune infiltration in lupus nephritis.4.The expression level of co-expressed autophagy-related genes in glomeruli and tubulointerstitium was preliminarily verified by dataset GSE112943.Finally,the renal puncture samples of patients with lupus nephritis were used further verify the expression level of key autophagy-related genes by immunohistochemical staining.Result1.In the glomerular samples of LN group and healthy control group(HC),a total of 351 differentially expressed genes were identified,of which 250 genes were significantly up-regulated and 101 genes were down-regulated in LN group.In tubulointerstitium samples,129 differentially expressed genes were identified,including 104 up-regulated genes and 25 down-regulated genes in LN group.All these genes were enriched in various viral infections and signal pathways related to type I interferon.2.28 autophagy-related genes are included in the differentially expressed genes of glomerulus.The enrichment analysis of GO and KEGG pathway shows that the biological processes of these 28 differential expression autophagy-related genes are mainly concentrated in the response to extracellular stimulation and nutritional level.There are 10 autophagy-related genes in the differentially expressed genes of tubulointerstitium,and these differentially expressed autophagy-related genes are mainly concentrated in extracellular stimulation and nutritional state response,autophagy regulation,etc.3.The results of immune infiltration analysis showed that the differentially expressed autophagy-related genes of glomerulus was negatively correlated with T cells regulatory,and the autophagy-related genes of tubulointerstitium were positively correlated with mast cells activated and negatively correlated with mast cells resting.4.The autophagy-related genes that co-express the difference between glomerulus and tubulointerstitium are EIF2AK2,TRIM22,ALB and PDK4.Among them,key autophagy-related genes EIF2AK2 and TRIM22 are verified in the validation set GSE112943.Furthermore,the immunohistochemical results showed that the expression level of EIF2AK2 and TRIM22 were higher in LN than health control.ConclusionWe found that the differentially expressed autophagy related genes in LN are mainly enriched in response to extracellular stimulus and nutrient level,and regulation of autophagy.The expression level of autophagy-related genes EIF2AK2 and TRIM222 were significantly increased in LN,which may participate in the occurrence and development of LN through autophagy,providing new insights into potential biomarkers and therapeutic targets for LN.