Scr eening of key genes and pathways of brain aging and prediction of potential effective Chinese medicinals: based on bioinformatics

Abstract

Microarray data of hippocampal tissue(HC) of the cognitively intact elderly(60-99 years old) were compared with those of the middle-aged and the young(20-59 years old) by bioinformatics techniques to initially screen out differentially expressed genes(DEGs) and then predict potential effective Chinese medicinals for the treatment of brain aging. The gene expression profile(accession: GSE11882) was downloaded from the Gene Expression Omnibus(GEO) and DEGs were screened based on R package. The key DEGs were identified by STRING, Cytoscape and the plug-in, followed by Gene Ontology(GO) term and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis. Then the key genes and the medical ontology information retrieval platform(Coremine Medical) were mapped against each other to single out the Chinese medicinals for the treatment of brain aging and construct the " Chinese medicinal-active constituent-target" network. Among the resultant 268 DEGs(246 down-regulated and 22 up-regulated), the 15 key genes were mainly involved in biological processes such as leukocyte migration, neutrophil activation, cell chemotaxis, microglia activation and response to external stimulus, and pathways such as inflammatory process, immune response, cytokine-cytokine receptor interaction, PI3 K-Akt signaling pathway, Rap1 signaling pathway, chemokine signaling pathway and Toll-like receptor signaling pathway. The potential effective Chinese medicinals were Notoginseng Radix et Rhizoma, Ginseng Radix et Rhizoma, Salviae Miltiorrhizae Radix et Rhizoma and Astragali Radix. The analysis of DEGs and key genes enhances the understanding of the mechanisms of brain aging. This study provides potential gene targets and ideas for the development of Chinese medicine for brain aging.