Linoleic acid derivative DCP-LA ameliorates stress-induced depression-related behavior by promoting cell surface 5-HT1A receptor translocation, stimulating serotonin release, and inactivating GSK-3β

Pimavanserin augments the efficacy of atypical antipsychotic drugs in a mouse model of treatment-refractory negative symptoms of schizophrenia

Negative symptoms are a core, pervasive, and often treatment-refractory phenotype of schizophrenia, one which contributes to poor functional outcome, ability to work, pursue educational goals, and quality of life, as well as caretaker burden. Improvement of negative symptoms in some patients with schizophrenia has been reported with some atypical antipsychotic drugs [AAPDs], but improvement is absent in many patients and partial in others. Therefore, more effective treatments are needed, and better preclinical models of negative symptoms are needed to identify them. Sub-chronic [sc] treatment of rodents with phencyclidine [PCP], a noncompetitive N-methyl-d-aspartate [NMDAR] antagonist, produces deficits in social interactions [SI] that have been widely studied as a model of negative symptoms in schizophrenia. Acute restraint stress [ARS] also provides a model of treatment-refractory negative symptoms [TRS] to AAPDs. By themselves, in sc-PCP mice, the AAPDs, risperidone, olanzapine, and aripiprazole, but not the selective 5-HT_2AR inverse agonist, pimavanserin [PIM], rescued the SI deficit in sc-PCP mice, as did the combination of PIM with sub-effective doses of each of these AAPDs. These three AAPDs alone did not rescue SI deficit in sc-PCP+2h-ARS mice, indicating these mice were treatment refractory. However, co-administration of PIM with any of the AAPDs significantly restored SI in these mice. PIM may be an effective adjunctive therapy for treating negative symptoms of schizophrenia in some patients who have failed to respond to AAPDs, but further studies are needed.

Current advances in metabolomic studies on non-motor psychiatric manifestations of Parkinson's disease (Review)

Life expectancy has increased worldwide and, along with it, a greater prevalence of age-dependent disorders, chronic illnesses and comorbidities can be observed. In 2019, in both Europe and the Americas, dementias ranked 3rd among the top 10 causes of death. Parkinson's disease (PD) is the second most frequent type of neurodegenerative disease. In the last decades, globally, the number of people suffering from PD has more than doubled to over 6 million. Of all the neurological disorders, PD increased with the fastest rate. This troubling trend highlights the stringent need for accurate diagnostic biomarkers, especially in the early stages of the disease and to evaluate treatment response. To gain a broad and complex understanding of the recent advances in the '-omics' research fields, electronic databases such as PubMed, Google Academic, and Science Direct were searched for publications regarding metabolomic studies on PD to identify specific biomarkers for PD, and especially PD with associated psychiatric symptomatology. Discoveries in the fields of metagenomics, transcriptomics and proteomics, may lead to an improved comprehension of the metabolic pathways involved in disease etiology and progression and contribute to the discovery of novel therapeutic targets for effective treatment options.

Glycogen Synthase Kinase-3: A Focal Point for Advancing Pathogenic Inflammation in Depression

Increasing evidence indicates that the host immune response has a monumental role in the etiology of major depressive disorder (MDD), motivating the development of the inflammatory hypothesis of depression. Central to the involvement of chronic inflammation in MDD is a wide range of signaling deficits induced by the excessive secretion of pro-inflammatory cytokines and imbalanced T cell differentiation. Such signaling deficits include the glutamatergic, cholinergic, insulin, and neurotrophin systems, which work in concert to initiate and advance the neuropathology. Fundamental to the communication between such systems is the protein kinase glycogen synthase kinase-3 (GSK-3), a multifaceted protein critically linked to the etiology of MDD and an emerging target to treat pathogenic inflammation. Here, a consolidated overview of the widespread multi-system involvement of GSK-3 in contributing to the neuropathology of MDD will be discussed, with the feed-forward mechanistic links between all major neuronal signaling pathways highlighted.

Rapid action of mechanism investigation of Yixin Ningshen tablet in treating depression by combinatorial use of systems biology and bioinformatics tools

ETHNOPHARMACOLOGICAL RELEVANCE

Yixin Ningshen tablet is a CFDA-approved TCM formula for treating depression clinically. However, little is known about its active compounds and related potential target proteins, so far, no researches have been performed to investigate its mechanism of action for the treatment of depression.

AIM OF THE STUDY

Here we develop an original bioinformatics pipeline composed of text mining tools, database querying and systems biology combinatorial analysis, which is applied to rapidly explore the mechanism of action of Yixin Ningshen tablet in treating depression.

MATERIALS AND METHODS

Text mining and database query were applied to identify active compounds in Yixin Ningshen tablet for the treatment of depression. Then SwissTargetPrediction was used to predict their potential target proteins. PubMed was retrieved to summarize known depression related systems biology results. Ingenuity Pathway Analysis (IPA) tools and STRING were applied to construct a compound-target protein-gene protein-differential protein-differential metabolite network with the integration of compound-target interaction and systems biology results, as well as enrich the target proteins related pathways. ChEMBL and CDOCKER were used to validate the compound-target interactions.

RESULTS

62 active compounds and their 286 potential target proteins were identified in Yixin Ningshen tablet for the treatment of depression. The construction of compound-target protein-gene protein-differential protein-differential metabolite network shrinked the number of potential target proteins from 286 to 133. Pathway enrichment analysis of target proteins indicated that Neuroactive ligand-receptor interaction, Calcium signaling pathway, Serotonergic synapse, cAMP signaling pathway and Gap junction were the common primary pathways regulated by both Yixin Ningshen Tablet and anti-depressant drugs, and MAPK, Relaxin, AGE-RAGE, Estrogen, HIF-1, Jak-STAT signaling pathway, Endocrine resistance, Arachidonic acid metabolism and Regulation of actin cytoskeleton were the specifically main pathways regulated by Yixin Ningshen tablet for the treatment of depression. Further validations based on references and molecular docking results demonstrated that Yixin Ningshen tablet could primarily target MAPT, CHRM1 and DRD1, thus regulating serotonergic neurons, cholinergic transmission, norepinephrine and dopamine reuptake for the treatment of depression.

CONCLUSIONS

This study displays the power of extensive mining of public data and bioinformatical repositories to provide answers for a specific pharmacological question. It furthermore demonstrates how the usage of such a combinatorial approach is advantageous for the biologist in terms of experimentation time and costs.

Serotonin 5-HT1A receptors modulate depression-related symptoms following mild traumatic brain injury in male adult mice

Traumatic brain injury is a complex phenomenon leading to neurological diseases and persistent disability that currently affects millions of people worldwide. Increasing evidence shows that a wide range of patients with mild traumatic brain injury (mTBI) suffer from depression during the initial stages of injury and the post-acute stages of recovery. However, the underlying mechanisms involved in depression following mTBI are still not fully understood. The aim of this study was to determine whether serotonin 5-hydroxytryptamine-1A (5-HT1A) receptor is involved in the regulation of depression-related behaviors following mild traumatic brain injury in mice. Mice with or without mTBI received intracerebroventricular injections of 5-HT1A receptor agonist (8-OH-DPAT) or antagonist (WAY-100635) for 5 days, then animals were subjected to behavioral tests. Four behavioral tests including novelty-suppressed feeding test, forced swim test, sucrose preference test and tail suspension test were used to evaluate depression-related symptoms in animals. Our results indicated that mTBI induction increased depression-like symptoms through altering serotonin 5-HT1A receptor activity in the brain. Activation of 5-HT1A receptor by a subthreshold dose of 8-OH-DPAT led to a significant decrease in depression-like behaviors, whereas blockade of 5-HT1A receptor by a subthreshold dose of WAY-100635 resulted in a considerable increase in depression-like phenotypes in mTBI-induced mice. The major strength of the present study is that depression-related symptoms were assessed in four behavioral tests. The present study supports the idea that disturbances in the function of serotonergic system in the brain following mTBI can play an important role in the regulation of depression-related behaviors.

Integrated Analysis Reveals Altered Lipid and Glucose Metabolism and Identifies NOTCH2 as a Biomarker for Parkinson's Disease Related Depression

Depression is a common comorbidity in Parkinson's disease (PD) but is underdiagnosed. We aim to investigate the altered metabolic pathways of Parkinson's disease-related depression (PDD) in plasma and to identify potential biomarkers for clinical diagnosis. Consecutive patients with PD were recruited, clinically assessed, and patients with PDD identified. Fasting plasma samples were collected from 99 patients and differentially expressed metabolites and proteins between patients with PDD and PD were identified using non-targeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomics and tandem mass tag (TMT)-based proteomics analysis, followed by an integrated analysis. Based on the above results, enzyme-linked immune sorbent assay (ELISA) tests were then performed to identify potential biomarkers for PDD. In clinics, patients with PDD suffered less hypertension and had lower serum low-density lipoprotein cholesterol and apolipoprotein B levels when compared to the other patients with PD. A total of 85 differentially expressed metabolites were identified in metabolomics analysis. These metabolites were mainly lipids and lipid-like molecules, involved in lipid and glucose metabolic pathways. According to proteomics analysis, 17 differentially expressed proteins were identified, and 12 metabolic pathways were enriched, which were predominantly related to glucose metabolism. Integrated analysis indicated that altered lipid and glucose metabolism in PDD may induce cellular injury through oxidative stress. Additionally, plasma levels of several proteins were confirmed to be significantly altered and correlated with depressive severity. NOTCH2 may be a potential blood biomarker for PDD, with an optimal cut-off point of 0.91 ng/ml, a sensitivity value of 95.65%, and a specificity value of 81.58%. Depressive symptoms are associated with lipid and glucose metabolism in patients with PD and NOTCH2 may be a potential blood biomarker for the clinical diagnosis of PDD.

The Relationship between Fatty Acids and Different Depression-Related Brain Regions, and Their Potential Role as Biomarkers of Response to Antidepressants

Depression is a complex disorder influenced by a variety of biological and environmental factors. Due to significant heterogeneity, there are remarkable differences in how patients respond to treatment. A primary objective of psychiatric research is to identify biological markers that could be used to better predict and enhance responses to antidepressant treatments. Diet impacts various aspects of health, including depression. The fatty acid composition of the Western diet, which has a high ratio of n-6:n-3 polyunsaturated fatty acids, is associated with increased incidence of depression. The brain is rich in lipids, and dietary fatty acids act within specific brain regions to regulate processes that impact emotional behavior. This manuscript reviews existing evidence demonstrating brain region-specific fatty acid profiles, and posits that specific fatty acids may serve as predictive biomarkers of response to antidepressants. Furthermore, increasing blood levels of certain fats, such as n-3s, via dietary intervention may serve as an adjunct to improve the efficacy of antidepressants. Notably, most of the existing research regarding fats and depression-related brain regions has focused on n-3s, as compared to n-6s, monounsaturated, and saturated fats. This review article will help guide future work investigating the relationships between fatty acids, brain regions, and antidepressant efficacy.

Stressed and Inflamed, Can GSK3 Be Blamed?

Psychological stress has a pervasive influence on our lives. In many cases adapting to stress strengthens organisms, but chronic or severe stress is usually harmful. One surprising outcome of psychological stress is the activation of an inflammatory response that resembles inflammation caused by infection or trauma. Excessive psychological stress and the consequential inflammation in the brain can increase susceptibility to psychiatric diseases, such as depression, and impair learning and memory, including in some patients with cognitive deficits. An emerging target to control detrimental outcomes of stress and inflammation is glycogen synthase kinase-3 (GSK3). GSK3 promotes inflammation, partly by regulating key transcription factors in the inflammation signaling pathway, and GSK3 can impair learning by promoting inflammation and by inhibiting long-term potentiation (LTP). Drugs inhibiting GSK3 may prove beneficial for controlling mood and cognitive impairments caused by excessive stress and the associated neuroinflammation.

Acute restraint stress impairs induction of long-term potentiation by activating GSK-3β

The present study investigated the effect of acute restraint stress on long-term potentiation (LTP) and the underlying mechanism. Induction of Schaffer collateral-CA1 LTP was suppressed in hippocampal slices from mice with 1-h restraint stress. Cell surface localization of the N-methyl-D-aspartate (NMDA) receptor subunits NR1 and NR2B and the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA1 and GluA2 was not affected in the hippocampus from mice with 1-h restraint stress. Phosphorylation of Akt at Ser473, but not at Thr308, and phosphorylation of GSK-3β at Ser9, but not at Tyr216, were significantly inhibited in the hippocampus with 1-h restraint stress. Taken together, the results of the present study show that acute restraint stress impairs induction of LTP by enhancing GSK-3β activity following suppressed Akt activity, without affecting cell surface localization of the NMDA and AMPA receptor subunits.