Heterogeneities of Site-Specific N-Glycosylation in the Hippocampus of Depression-like Behavior Models in Mice Induced by Acute Stress and Chronic Stress

It is well established that acute and chronic stress contributes to the onset and progression of depression, but the underlying mechanisms have not been elucidated. Here an integrated N-glycoproteomic and proteomic analysis was performed to investigate heterogeneities of glycoprotein and site-specific glycosylation between the hippocampi of control, acute stress-affected (AS), and chronic mild stress-affected (CMS) mice. 1063 unique intact N-glycopeptides, 116 N-glycan compositions, and 512 glycosylation sites were identified. CMS and AS had significant effects on glycosylation. CMS reduced multiantenna glycosylation (N8H8 and N6H5F1S1) more strongly, while AS reduced multiantenna glycosylation (N5H3F1) more strongly. CMS inhibited high-mannose synthesis with high polymerization (N2H9 and N2H8), while AS inhibited high-mannose synthesis with low polymerization (N2H6, H2H5). Furthermore, 26 and 39 glycosylation-related genes (GRGs) were identified in the AS and CMS groups, separately. Functional enrichment analysis for GRGs in the AS and CMS groups exhibited that the up-regulated functions were leading edge membrane and cell adhesion molecule binding; meanwhile, the down-regulated functions were cAMP signaling pathways. Finally, tSNE analysis based on ScRNA-seq revealed that core GRGs were highly expressed in astrocytes. All of these findings improve our understanding of glycosylation in stress-related depression, providing valuable data resources for depression pathogenesis exploration and novel therapeutic target discovery.