Project description:We conducted proteomic profiling of plasma, identifying both overlapping and unique differential proteins in adolescent patients diagnosed with major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ). Our results showed that the protein signatures of adolescent psychiatric disorders differ significantly from those of adults. We propose potential targets for drug development aimed at the prevention or precision therapy of these psychiatric disorders. These findings enhance our understanding of the molecular etiology of adolescent psychiatric disorders. The specific biomolecular signatures of MDD, BD, and SZ could potentially serve as targets for the development of novel interventions aimed at prevention, early diagnosis, and treatment of these mental health conditions.
Project description:MicroRNAs have been implicated in the pathology not only of cancer, but also of psychiatric diseases, such as bipolar disorder and schizophrenia. As several psychiatric disorders share the same risk genes, we hypothesized that this microRNA could also be associated with attention-deficit/hyperactivity disorder (ADHD) and that this association to psychiatric disorders might be due to the variable number of tandem repeats (VNTR) polymorphism within the internal miR-137 (Imir137) promoter (PMID 18316599; PMID 25154622). To further understand the role of the microRNA 137 in the brain a knock-down of miR-137 expression in SH-SY5Y neuroblastoma cells was performed followed by expression analysis using a microarray.
Project description:Genetic evidence indicates disrupted epigenetic regulation as a major risk factor for psychiatric disorders, but the molecular mechanisms that drive this association are undetermined. EHMT1 is an epigenetic repressor that is causal for Kleefstra Syndrome (KS), a neurodevelopmental disorder (NDD) leading to ID, and is associated with schizophrenia. Here, we show that reduced EHMT1 activity decreases NRSF/REST protein leading to abnormal neuronal gene expression and progression of neurodevelopment in human iPSC. We further show that EHMT1 regulates NRSF/REST indirectly via repression of miRNA leading to aberrant neuronal gene regulation and neurodevelopment timing. Expression of a NRSF/REST mRNA that lacks the miRNA-binding sites restores neuronal gene regulation to EHMT1 deficient cells. Importantly, the EHMT1-regulated miRNA gene set with elevated expression is enriched for NRSF/REST regulators with an association for ID and schizophrenia. This reveals a molecular interaction between H3K9 dimethylation and NSRF/REST contributing to the aetiology of psychiatric disorders.
Project description:In psychiatric disorders, common and rare genetic variants cause widespread dysfunction of cells and their interactions, especially in the prefrontal cortex, giving rise to psychiatric symptoms. To better understand these processes, we traced the effects of common and rare genetics, and cumulative disease risk scores, to their molecular footprints in human cortical single-cell types. We demonstrated that examining gene expression at single-exon resolution is crucial for understanding the cortical dysregulation associated with diagnosis and genetic risk derived from common variants. We then used disease risk scores to identify a core set of genes that serve as a footprint of common and rare variants in the cortex. Pathways enriched in these genes included dopamine regulation, circadian entrainment, and hormone regulation. Single-nuclei-RNA-sequencing pinpointed these enriched genes to excitatory cortical neurons. This study highlights the importance of studying sub-gene-level genetic architecture to classify psychiatric disorders based on biology rather than symptomatology, to identify novel targets for treatment development.
Project description:Dysregulated neurite outgrowth and synapse formation underlie many psychiatric disorders. Wolfram syndrome (WS) mainly caused by WFS1 deficiency is a monogenic genetic disease manifested by severe psychiatric disorders. Due to athe lack of proper human disease models, the underlying mechanism is poorly understood. Particularly, whether and how WFS1 deficiency affects synapse formation remain elusive. By mirroring the complexity of human brain development with cerebral organoids derived from human embryonic stem cells (hESCs) harboring WFS1 loss of function (LOF), we found that WFS1-deficient cerebral organoids not only recapitulated the neuronal loss phenotype in WS patients, but also exhibited significantly impaired synapse formation associated with reduced astrocytes, suggesting a defective structural basis for psychiatric disorders elicited by WFS1 deficiency. To further unravel the complexity of interplay between neurons and astrocytes, each neural cell type was respectively differentiated from hESCs harboring WFS1 LOF. WFS1 deficiency in neurons autonomously delayed neuronal differentiation with altered expressions of genes associated with psychiatric disorders, and impaired neurite outgrowth and reduced synapse formation associated with elevated cytosolic calcium. Interestingly, WFS1 deficiency in astrocytes decreased the expression of glutamate transporter EAAT2 and compromised glutamate uptake, causing reduced neurite outgrowth with increased cytosolic calcium when co-cultured with wildtype (WT) neurons, highlighting pathogenic role of WFS1-deficient astrocytes. Importantly, restoring EAAT2 expression in astrocytes by riluzole treatment significantly alleviated reduced neurite outgrowth phenotype in WT neurons co-cultured with WFS1-deficient astrocytes. Altogether, our study provides novel insights into how WFS1 deficiency affects neurite outgrowth and synapse formation, potentially contributing to predisposition of psychiatric disorders, and offers a potential strategy of therapy.
Project description:DNA methylation has become increasingly recognized in the etiology of psychiatric disorders. Because brain tissue is not accessible in living humans, epigenetic studies are most often conducted in blood. Saliva is often collected for genotyping studies but is rarely used to examine DNA methylation because the proportion of epithelial cells and leukocytes varies extensively between individuals. The goal of this study was to evaluate whether saliva DNA is informative for studies of psychiatric disorders. Saliva and blood methylation was clearly distinguishable though there was positive correlation overall. There was little correlation in CpG sites within relevant candidate genes. Correlated CpG sites were more likely to occur in areas of low CpG density (i.e. CpG shores and open seas). There was more variability in CpG sites from saliva than blood, which may reflect its heterogeneity. Thus, this study provides a framework for using DNA methylation from saliva and suggests that DNA methylation of saliva may offer distinct opportunities for epidemiological and longitudinal studies of psychiatric traits.