Gastric mucosal differentially expressed genes after bariatric surgery: Effects on sterol-related pathways

Obesity is currently recognized as a serious global health problem, which accounts for a considerable morbidity and mortality burden. Bariatric surgery is widely accepted as one of the most effective treatments for severe obesity. Roux-en-Y Gastric Bypass (RYGB) is a common type of bariatric surgery. Although the clinical impact of RYGB has been widely studied, the effects of this intervention at the molecular and genetic levels remain largely unknown. In this study, we aimed to identify differentially expressed genes in gastric mucosa after bariatric surgery vs. before in order to recognize genes and pathways influenced by surgery. Data of GSE76762 was downloaded from GEO (NCBI) database. Gene expression of after surgery samples were compared with before. Genes with a │Log fold change (LFC) │ > 1 and adjusted p-value < 0.05 were defined as differentially expressed genes. It was found that 11 genes were differentially upregulated and 6 genes were differentially downregulated after bariatric surgery. Protein-protein interactions assessed using STRNG online database was significant (p-value: 0.000202). SCD, INSIG1, CYP51A1, and LDLR have strong protein-protein interactions. Gene-gene interaction was investigated using GeneMANIA which showed the high co-expression score (97.78 %). GO and pathway enrichment analysis was investigated using EnrichR. Cholesterol Homeostasis, Sterol Homeostasis, and Cellular Response to Sterol are the best results of biological process. Metabolism of steroids, Steroid regulatory element binding proteins signaling, and Bile secretion are the best results of Reactome, WikiPathway, and KEGG, respectively. Importantly, associations of LDLR, KCNJ13, and PMP22 with Familial hypercholesterolemia, Hyperlipoproteinemia, Charcot-marie-tooth disease type 1 and 4, and Leber congenital amaurosis were discovered.