Observation of GPI gene expression and bioinformatics analysis of its function in peripheral blood and brain tissues of patients with Alzheimer's disease

MA Guowei; ZHONG Xin; DU Ke; GONG Shiqiang; LIU Mingyan; WEI Minjie

doi:10.3969/j.issn.1002-266X.2018.48.001

Abstract：Objective The expression of glucose-6-phosphate isomerase (GPI) gene in peripheral blood and brain tissues of patients with Alzheimer's disease (AD) was observed based on GEO chip technology, and the relationship between GPI function and the pathogenesis of AD was analyzed.Methods We obtained 18 cases of frontal cortex, 19 cases of temporal cortex, 19 cases of hippocampus, and 14 cases of peripheral blood samples from the healthy elderly.In the AD patients, 15 cases of the frontal cortex of the brain, 10 cases of the temporal cortex, 29 cases of the hippocampus, and 14 cases of the peripheral blood samples were selected.The GEO database was used to screen the relevant chips for AD, and the GPI genes in peripheral blood samples and brain tissue samples of the healthy elderly and AD patients were detected.Screening out the genes related to GPI via protein-protein interaction (PPI) network map.Gene function enrichment analysis was performed by gene ontology (GO) analysis and we used the Kyoto Gene and Genomic Encyclopedia (KEGG) for the enrichment analysis and to screen out the biological functions or pathways in which GPI genes may be involved and primarily affected.ResultsPeripheral blood microarray analysis showed that the expression of GPI gene in the peripheral blood of females was lower than that in males, and was lower than that in male AD patients (P＜0.05).In the same gender group, the expression of GPI gene in the peripheral blood of AD patients was lower than that in the healthy people (P＜0.05).The results of brain tissue microarray analysis showed that the expression of GPI gene in the hippocampus of AD patients was significantly down-regulated, which was lower than that of the other brain regions (frontal and temporal cortex) and was not related to gender (P＜0.05).The expression of GPI gene continued to decrease with the severity of AD (P＜0.05).Ten highly GPI-related genes were screened out by PPI network map, including PKM, TPI1, PFKL, PKLR, PGM1, PFKP, ENO3, PFKM, H6PD, and TKT.GO analysis and KEGG functional enrichment analysis showed that the GPI gene and its related 10 genes were highly correlated with energy metabolism processes such as glycolysis, synthesis, decomposition and metabolism in functional enrichment.ConclusionThe expression of GPI gene was down-regulated in the peripheral blood and hippocampus of AD patients, and the expression of GPI is continuously decreased with the increase of AD disease;GPI gene and its related genes might be involved in the functional regulation of energy metabolism in the hippocampus of AD patients.