Biological processes and pathway changes in isoflurane-induced anesthesia revealed by bioinformatics analysis of gene expression profiles.

OBJECTIVE: To identify differentially expressed genes (DEGs) and further analyze potential biological processes and pathways involved in isoflurane-induced anesthesia.

METHODS: Microarray data (ID: GSE64617) from rat brains treated with exposure to either isoflurane in oxygen (2%) (test group) or oxygen alone (control group) for 15 min were downloaded from Gene Expression Omnibus. Data pre-processing was performed using the Affy package, followed by DEG screening using the limma package. Protein-protein interactions (PPIs) among DEGs were obtained from STRING (Search Tool for the Retrieval of Interacting Genes/Proteins), and then visualized by constructing a network using Cytoscape. Functional and pathway enrichment analyses were further implemented to identify the biological processes and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways enriched by DEGs.

RESULTS: A total of 240 DEGs were identified between the test and control groups, including 128 up-regulated DEGs and 112 down-regulated DEGs in the test group, of which 17 DEGs with a connectivity degree >4 were identified as hub genes (e.g., Pik3r1 and Pik3r2) in the constructed PPI network. Additionally, Slc17a7 and Camk4 interacted with Syn1, and Pik3r1 interacted with Pik3r2. Enrichment analysis further revealed the significantly enriched biological processes of 'synaptic transmission', 'cell-cell signaling' and 'transmission of nerve impulse' (e.g., Slc17a7, Camk4, Syn1, Gria1, Prkcg and Lphn1), as well as KEGG pathways including 'focal adhesion', 'Fc γ R-mediated phagocytosis' (e.g., Prkcg, Pik3r1 and Pik3r2), and 'regulation of actin cytoskeleton' (e.g., Pik3r1 and Pik3r2).

CONCLUSIONS: The identified DEGs significantly enriched in biological processes and KEGG pathways might be implicated in isoflurane-induced anesthesia.