Decoding the Transcriptional Response to Ischemic Stroke in Obese and Non-obese Mice Brain

Ischemic Stroke (IS) is a serious cerebrovascular disease, which leads to irreversible damage or death of brain cells. Effective control of stroke risk factors can effectively reduce the incidence of IS. However, there was an "obesity paradox" about the relationship between obesity and the prognosis of IS, in which obesity would not bring worse outcomes than non-obese IS patients.

Herein, we aimed to investigate the transcriptional response to IS in obese and nonobese mice brain via RNA-Seq technology. The datasets of obese and non-obese mice with/without IS were obtained from the Gene Expression Omnibus (GEO) database.

Differentially expressed genes (DEGs) between Control and Obesity (DEGsObesity) and between Obesity and Obese-Stroke (DEGsObese-Stroke) were identified. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and Protein-Protein Interaction (PPI) network analysis were performed to predict the function of DEGs. 28 and 109 DEGs were screened in DEGsObesity and DEGsObese-Stroke, respectively.

Significantly, in the top 10 key-genes of DEGsObese-Stroke (Tnf, Lgals3, Serpinb2, Ly6c2, Chil3, Clec4e, Mmp3, Mefv, Spn, Tlr8), Tnf and Mefv were involved in the NOD-like receptor signaling pathway, which was consistent with KEGG pathway enrichment results. And Chil3, as a mononuclear cell marker, was significantly elevated in Obese-Stroke compared with Stroke, suggesting mononuclear cell, rather than other peripheral immune cells, infiltrated into the brain of Obese-stroke.

Hence, we concluded that obesity could affect the brain microenvironment at the transcriptome level and Stroke after obesity could lead to more changes in NOD-like receptor signaling pathway and monocyte infiltration, compared with non-obese Stroke.