Ribosomal dysregulation: A conserved pathophysiological mechanism in human depression and mouse chronic stress
The biological underpinnings of major depressive disorder (MDD) heterogeneity are unknown, in part due to the poor association between MDD models and clinical endpoints. We compared transcriptomic profiles of human postmortem MDD brain tissue and chronic variable stress (CVS)-exposed mice to identify orthologous genes. A downregulation of ribosomal protein genes (RPGs) and upregulation of associated RP pseudogenes in the prefrontal cortex of several independent cohorts from both human MDD and mouse CVS tissue prompted a seeded gene co-expression analysis using the RPGs altered in both groups. Downregulated RPGs were found to regulate synaptic changes in human MDD and mouse CVS through a RP pseudogene-driven mechanism. In vitro and in silico analysis further suggested that the inverse RPG/RP pseudogene association was a glucocorticoid-driven response and reversed during MDD remission. Thus, stress-induced alterations in RPGs may contribute to synaptic dysregulation in MDD, providing a mechanism for the variability in depression presentation. Overall design: Comparative analysis of molecular data (mRNA) from different experimental systems of chronic stress and major depressive disorder (MDD).