Absence of Wdr13 Gene Predisposes Mice to Mild Social Isolation - Chronic Stress, Leading to Depression-Like Phenotype Associated With Differential Expression of Synaptic Proteins

Reduced Neurite Arborization in Primary Dopaminergic Neurons in Autism-Like Shank3B-Deficient Mice

Despite many studies on dopamine changes in autism, specific alterations in midbrain dopamine neurons projecting to the striatum and cortex remain unclear. Mouse models with diverse SH3 domain and ankyrin repeat containing protein 3 (Shank3) deficiencies are used for investigating autistic symptoms and underlying neurobiological mechanisms. SHANK3 belongs to postsynaptic proteins crucial for synapse formation during development, and disruptions in SHANK3 structure could lead to impaired neurite outgrowth and altered dendritic arborization and morphology. Therefore, we aimed to investigate whether Shank3 deficiency (Shank3B) leads to changes in the morphology of primary neuronal cell cultures from dopaminergic brain regions of neonatal mouse pups and whether it results in alterations in synaptic proteins in dopaminergic nerve pathway projection areas (striatum, frontal cortex). Significantly reduced neurite outgrowth was observed in primary dopaminergic neurons from the midbrain and striatum of Shank3-deficient compared to WT mice. A decrease in Synapsin I immunofluorescence signal in the cortical neurons isolated from Shank3-deficient mice was found, although neurite arborization changes were less severe. Importantly, the deficit in the length of the longest neurite was confirmed in primary cortical neurons isolated from Shank3-deficient mice. No changes in the gene expression of synaptic proteins were observed in the striatum and frontal cortex of Shank3-deficient mice, but an altered gene expression profile of dopaminergic receptors was found. These results show structural changes of dopaminergic neurons, which may explain autistic symptomatology in the used model and provide a basis for understanding the long-term development of autistic symptoms.

Dynamic functional connectivity patterns predict early antidepressant treatment response in drug-naïve, first-episode adolescent MDD

Objective

Adolescents with major depressive disorder (MDD) exhibit abnormal dynamic functional connectivity (dFC) patterns, but it remains unclear whether these aberrant dFC patterns are linked to antidepressant treatment. The aim of this study is to investigate whether dFC patterns will be changed by antidepressant treatment, as well as whether baseline dFC pattern could predict treatment response in adolescent MDD patients.

Method

We included 35 drug-naïve, first-episode MDD adolescents (age 14.40 ± 1.24; 8 males and 27 females) and 24 healthy controls (HCs, age 14.21 ± 1.41; 11 males and 13 females). All MDD adolescents received 6 weeks of antidepressant treatment. Resting state and T1 MRI data were collected in MDD adolescents before and after treatment and in HCs. Independent component analysis (ICA) was used to compare the different dFC pattern between MDD adolescents and HCs at baseline, as well as which between before and after treatment in MDD adolescents. Finally, Pearson correlation and multivariate linear regression analyses were used to explore the associations between dFC pattern and changed score of BDI in MDD adolescents.

Results

The mean dFC value between right inferior frontal gyrus (IFG) and bilateral insular cortex (IC; right, r = -0.461, p-FDR = 0.012; left, r = -0.518, p-FDR = 0.007) at baseline were negatively correlated with BDI score reduction. The mean dFC value between left frontal pole (FP) and right superior parietal lobule (SPL) after treatment was positively correlated with BDI score reduction (r = 0.442, p-FDR = 0.014). And the mean dFC values between right IFG and bilateral IC (right, β = -1.563, p-FDR = 0.021; left, β = -1.868, p-FDR = 0.012) at baseline could predict antidepressant treatment response.

Conclusion

These findings demonstrate that dFC patterns between some brain areas could be a prospective factor for predicting antidepressant treatment response.

Comprehensive Review of Chronic Stress Pathways and the Efficacy of Behavioral Stress Reduction Programs (BSRPs) in Managing Diseases

The connection between chronic psychological stress and the onset of various diseases, including diabetes, HIV, cancer, and cardiovascular conditions, is well documented. This review synthesizes current research on the neurological, immune, hormonal, and genetic pathways through which stress influences disease progression, affecting multiple body systems: nervous, immune, cardiovascular, respiratory, reproductive, musculoskeletal, and integumentary. Central to this review is an evaluation of 16 Behavioral Stress Reduction Programs (BSRPs) across over 200 studies, assessing their effectiveness in mitigating stress-related health outcomes. While our findings suggest that BSRPs have the potential to enhance the effectiveness of medical therapies and reverse disease progression, the variability in study designs, sample sizes, and methodologies raises questions about the generalizability and robustness of these results. Future research should focus on long-term, large-scale studies with rigorous methodologies to validate the effectiveness of BSRPs.

Hypothalamic protein profiling from mice subjected to social defeat stress

The Hypothalmic-Pituitary-Adrenal axis also known as the HPA axis is central to stress response. It also acts as the relay center between the body and the brain. We analysed hypothalamic proteome from mice subjected to chronic social defeat paradigm using iTRAQ based quantitative proteomics to identify changes associated with stress response. We identified greater than 2000 proteins after processing our samples analysed through Q-Exactive (Thermo) and Orbitrap Velos (Thermo) at 5% FDR. Analysis of data procured from the runs showed that the proteins whose levels were affected belonged primarily to mitochondrial and metabolic processes, translation, complement pathway among others. We also found increased levels of fibrinogen, myelin basic protein (MBP) and neurofilaments (NEFL, NEFM, NEFH) in the hypothalamus from socially defeated mice. Interestingly, research indicates that these proteins are upregulated in blood and CSF of subjects exposed to trauma and stress. Since hypothalamus secreted proteins can be found in blood and CSF, their utility as biomarkers in depression holds an impressive probability and should be validated in clinical samples.

Neuroproteomics: Unveiling the Molecular Insights of Psychiatric Disorders with a Focus on Anxiety Disorder and Depression

Anxiety and depression are two of the most common mental disorders worldwide, with a lifetime prevalence of up to 30%. These disorders are complex and have a variety of overlapping factors, including genetic, environmental, and behavioral factors. Current pharmacological treatments for anxiety and depression are not perfect. Many patients do not respond to treatment, and those who do often experience side effects. Animal models are crucial for understanding the complex pathophysiology of both disorders. These models have been used to identify potential targets for new treatments, and they have also been used to study the effects of environmental factors on these disorders. Recent proteomic methods and technologies are providing new insights into the molecular mechanisms of anxiety disorder and depression. These methods have been used to identify proteins that are altered in these disorders, and they have also been used to study the effects of pharmacological treatments on protein expression. Together, behavioral and proteomic research will help elucidate the factors involved in anxiety disorder and depression. This knowledge will improve preventive strategies and lead to the development of novel treatments.

Targeting GATA1 and p2x7r Locus Binding in Spinal Astrocytes Suppresses Chronic Visceral Pain by Promoting DNA Demethylation

Irritable bowel syndrome is a gastrointestinal disorder of unknown etiology characterized by widespread, chronic abdominal pain associated with altered bowel movements. Increasing amounts of evidence indicate that injury and inflammation during the neonatal period have long-term effects on tissue structure and function in the adult that may predispose to gastrointestinal diseases. In this study we aimed to investigate how the epigenetic regulation of DNA demethylation of the p2x7r locus guided by the transcription factor GATA binding protein 1 (GATA1) in spinal astrocytes affects chronic visceral pain in adult rats with neonatal colonic inflammation (NCI). The spinal GATA1 targeting to DNA demethylation of p2x7r locus in these rats was assessed by assessing GATA1 function with luciferase assay, chromatin immunoprecipitation, patch clamp, and interference in vitro and in vivo. In addition, a decoy oligodeoxynucleotide was designed and applied to determine the influence of GATA1 on the DNA methylation of a p2x7r CpG island. We showed that NCI caused the induction of GATA1, Ten-eleven translocation 3 (TET3), and purinergic receptors (P2X7Rs) in astrocytes of the spinal dorsal horn, and demonstrated that inhibiting these molecules markedly increased the pain threshold, inhibited the activation of astrocytes, and decreased the spinal sEPSC frequency. NCI also markedly demethylated the p2x7r locus in a manner dependent on the enhancement of both a GATA1–TET3 physical interaction and GATA1 binding at the p2x7r promoter. Importantly, we showed that demethylation of the p2x7r locus (and the attendant increase in P2X7R expression) was reversed upon knockdown of GATA1 or TET3 expression, and demonstrated that a decoy oligodeoxynucleotide that selectively blocked the GATA1 binding site increased the methylation of a CpG island in the p2x7r promoter. These results demonstrate that chronic visceral pain is mediated synergistically by GATA1 and TET3 via a DNA-demethylation mechanism that controls p2x7r transcription in spinal dorsal horn astrocytes, and provide a potential therapeutic strategy by targeting GATA1 and p2x7r locus binding.

WDR13: A Novel Gene Implicated in Non-Syndromic Intellectual Disability

Investigating novel genetic variants involved in intellectual disability (ID) development is essential. X-linked intellectual disability (XLID) accounts for over 10% of all cases of ID in males. XLID genes are involved in many cellular pathways and processes. Some of them are not specific to the development and functioning of the neural system. The implementation of exome sequencing simplifies the search for novel variants, especially those less expected. Here, we describe a nonsense variant of the XLID gene, WDR13. The mutation c.757C>T (p.Arg253Ter) was uncovered by X-chromosome exome sequencing in males with a familial form of intellectual disability. Quantitative PCR (qPCR) analysis showed that variant c.757C>T caused a significant decrease in WDR13 expression in the patient's fibroblast. Moreover, it dysregulated other genes linked to intellectual disability, such as FMR1, SYN1, CAMK2A, and THOC2. The obtained results indicate the pathogenic nature of the detected variant and suggest that the WDR13 gene interacts with other genes essential for the functioning of the nervous system, especially the synaptic plasticity process.

Phosphoproteomic profiling of the hippocampus of offspring rats exposed to prenatal stress

INTRODUCTION

Prenatal stress (PS) can cause depression in offspring. However, the underlying biological mechanism of these influences is still unclear. This work was implemented to investigate the molecular mechanisms of depressive-like behavior of offspring rats insulted with PS.

METHODS

Relative quantitative phosphoproteomics of the hippocampus of PS susceptibility (PS-S) and control (CON) rat offspring was performed using  liquid chromatography-tandem mass spectrometry to confirm known pathways and to identify new mechanisms involved in depression.

RESULTS

A total of 6790 phosphopeptides, 9817 phosphorylation sites, and 2978 phosphoproteins were detected. Among the 2978 phosphoproteins, 1760 (59.09%) had more than two phosphorylated sites, the ENSRNOP00000023460 protein had more than 117 phosphorylated sites, and the average distribution of modification sites per 100 amino acids was 2.97. There were 197 different phosphopeptides, including 140 increased phosphopeptides and 57 decreased phosphopeptides in the PS-S offspring rats, compared to the CON offspring rats. These differential phosphopeptides corresponded to 100 upregulated and 44 downregulated phosphoproteins, respectively. Gene ontology enrichment analysis revealed that these different phosphoproteins in the top five enriched terms in the cellular component, molecular function, and biological proces categories were involved in a total of 35 different phosphoproteins, and these phosphoproteins were mainly related to myelin-, microtubule- and synapse-associated proteins. The enrichment of Kyoto Encyclopedia of Genes and Genome pathways was found to be involved in many essential biological pathways, and the top five pathways included amphetamine addiction, insulin secretion, Cushing syndrome, and the circadian entrainment signaling pathway. These first five pathways were related to nine phosphoproteins, including Adcy9, Apc, Cacna1c, Camk2a, Camk2b, Camk2g, Ctnnd2, Grin2a, and Stx1a. The full data are available via ProteomeXchange with identifier PXD019117.

CONCLUSION

We preliminarily identified 144 different phosphoproteins involved in myelin, microtubule, and synapse formation and plasticity in the hippocampus of susceptible offspring rats exposed to PS.