The Compensatory Immune-Regulatory Reflex System (CIRS) in Depression and Bipolar Disorder

Immune Aberrations in Obsessive-Compulsive Disorder: a Systematic Review and Meta-analysis

Some lines of evidence have indicated that immune dysregulation could play a role in the pathophysiology of obsessive-compulsive disorder (OCD). However, results have been inconsistent across studies. Thus, a systematic review and meta-analysis of studies measuring immune mediators in participants with OCD compared to healthy controls (HC) was conducted. The PubMed/MEDLINE, PsycINFO, and EMBASE electronic databases were systematically searched from inception through June 21, 2018. Sixteen studies met inclusion criteria comprising data from 1001 participants (538 with OCD and 463 were HCs). Levels of TNF-α, IL-6, IL-1β, IL-4, IL-10, and interferon-γ did not significantly differ between participants with OCD and healthy controls. In addition, the ex vivo production of TNF-α and IL-6 by isolated macrophages did not significantly differ between participants with OCD and HCs. Nevertheless, included studies have varied in methodological quality with the enrollment of samples that differed regarding medication status, the proper matching of OCD participants and HCs, age groups, and the presence of psychiatric comorbidities. In conclusion, an association between immune dysregulation and OCD remains unproven. Future studies should consider enrolling larger and more homogeneous samples with OCD.

Generalized Anxiety Disorder (GAD) and Comorbid Major Depression with GAD Are Characterized by Enhanced Nitro-oxidative Stress, Increased Lipid Peroxidation, and Lowered Lipid-Associated Antioxidant Defenses

Accumulating evidence shows that nitro-oxidative pathways play an important role in the pathophysiology of major depressive disorder (MDD) and bipolar disorder (BD) and maybe anxiety disorders. The current study aims to examine superoxide dismutase (SOD1), catalase, lipid hydroperoxides (LOOH), nitric oxide metabolites (NOx), advanced oxidation protein products (AOPP), malondialdehyde (MDA), glutathione (GSH), paraoxonase 1 (PON1), high-density lipoprotein cholesterol (HDL), and uric acid (UA) in participants with and without generalized anxiety disorder (GAD) co-occurring or not with BD, MDD, or tobacco use disorder. Z unit-weighted composite scores were computed as indices of nitro-oxidative stress driving lipid and protein oxidation. SOD1, LOOH, NOx, and uric acid were significantly higher and HDL and PON1 significantly lower in participants with GAD than in those without GAD. GAD was more adequately predicted by increased SOD + LOOH + NOx and lowered HDL + PON1 composite scores. Composite scores of nitro-oxidative stress coupled with aldehyde and AOPP production were significantly increased in participants with comorbid GAD + MDD as compared with all other study groups, namely MDD, GAD + BD, BD, GAD, and healthy controls. In conclusion, GAD is characterized by increased nitro-oxidative stress and lipid peroxidation and lowered lipid-associated antioxidant defenses, while increased uric acid levels in GAD may protect against aldehyde production and protein oxidation. This study suggests that increased nitro-oxidative stress and especially increased SOD1 activity, NO production, and lipid peroxidation as well as lowered HDL-cholesterol and PON1 activity could be novel drug targets for GAD especially when comorbid with MDD.

Metoprolol, N-Acetylcysteine, and Escitalopram Prevents Chronic Unpredictable Mild Stress-Induced Depression by Inhibition of Endoplasmic Reticulum Stress

Background: Endoplasmic reticulum stress (ERS) has been recently suggested to be activated in the major depressive disorder (MDD). However, whether ERS is a potential therapeutic target for MDD is largely unknown. Here we attempted to assess the preventive effect of metoprolol (MET), N-acetylcysteine (NAC), and escitalopram (ESC) on chronic unpredictable mild stress (CUMS)-induced depression and investigate whether ERS mediates the antidepressant role of these drugs. Method: Forty-five sprague-dawley rats were randomly divided into five groups: control, CUMS, CUMS+ESC, CUMS+NAC, and CUMS+MET. Weight measurement, open field activity and sucrose preference were performed before and after stress. Hippocampal nerve cells and capillary ultrastructure were observed by transmission electron microscope, and hippocampal cells apoptosis were detected by flow cytometry. Furthermore, expression of ERS markers glucose-regulated protein 78 (GRP78), C/EBP-homologous protein (CHOP), and caspase-12 were measured by western blot and qRT-PCR. Results: The CUMS-induced rats showed significantly increased depressive-like behaviors including decreased open field activity and sucrose preference. Moreover, CUMS-exposed rats exhibited significantly increased hippocampal cell apoptosis, and showed damage in hippocampal nerve cells and capillary ultrastructure. Furthermore, ESC and NAC not only mitigated depressive-like behaviors, but also decreased apoptosis and pathologies, while MET fail to decrease apoptosis. Moreover, CUMS stimulation significantly elevated ERS by increasing the levels of GRP78, CHOP, and decreasing the level of caspase-12, while ESC, NAC, and MET significantly decreased the ERS. Conclusion: ESC, NAC, and MET might prevent the MDD partly through inactivating the ERS. These findings demonstrated ERS as a novel treatment target for depression.