Comparative Proteomics of Rat Olfactory Bulb Reveal Insights Into Susceptibility and Resilience to Chronic-Stress-Induced Depression or Anxiety

Abstract

As a main risk factor of both anxiety and depression, chronic stress can cause the abnormality of olfactory bulb (OB). However, the unique and common neurobiological underpinnings underlying the OB dysfunction of these two disorders are still poorly understood. Previously, we have built depression-susceptible (Dep-Sus), anxiety-susceptible (Anx-Sus) and insusceptible (Insus) groups through the use of a valid chronic mild stress (CMS) regime. To continuously explore the protein expression changes in these three groups, comparative quantitative proteomics analysis was conducted on the rat OB as crucial part of the olfactory system. Next, bioinformatics analyses were implemented whereas protein expressions were independently analyzed by parallel reaction monitoring (PRM) or Western blot (WB). The OB-proteome analysis identified totally 133 differentially expressed proteins as a CMS response. These deregulated proteins were involved in multiple functions and significant pathways potentially correlated with phenotypes of maladaptive behavior of depression or anxiety as well as adaptive behavior, and hence might act as potential candidate protein targets. The subsequent PRM-based or WB-based analyses showed that changes in Nefl, Mtmr7 and Tk2; Prkaca, Coa3, Cox6c2, Lamc1 and Tubal3; and Pabpn1, Nme3, Sos1 and Lum were uniquely associated with Dep-Sus, Anx-Sus, and Insus groups, respectively. This suggested that the identical CMS differently impacted the olfactory protein regulation system. To sum up, our present data as a useful proteomics underpinning provided the common and distinct molecular insights into the biochemical understanding of OB dysfunction underlying susceptibility and resiliency to chronic-stress-induced anxiety or depression.