Rare recurrent copy number variations in metabotropic glutamate receptor interacting genes in children with neurodevelopmental disorders

Lifelong exposure to polystyrene-nanoplastics induces an attention-deficit hyperactivity disorder-like phenotype and impairs brain aging in mice

The accumulation of plastic waste in the environment, breaking down into micro- and nanoplastics, poses significant threats to ecosystem and human health. Plastic particles have been detected in human blood, urine, and placental tissue, indicating widespread exposure. While their long-term health impacts remain unclear, developing brains, especially in fetuses and children, may be vulnerable, potentially resulting in behavioral changes or neurodevelopmental disorders. This study explores the effects of chronic exposure to 23-nm polystyrene nanoplastics at 10 µg/day/kg in wild-type mice across life stages, using exposure levels reflective of human reality. Maternal exposure disrupted critical developmental milestones in pups. In adulthood, exposed mice exhibited Attention-Deficit Hyperactivity Disorder (ADHD)-like traits, including hyperactivity, increased risk-taking behaviors, and impaired motor learning and executive functions. In aging mice, exposure was associated with a lower epileptic threshold, with developing seizures. These behavioral changes were linked to altered gene and synaptic protein expression associated with ADHD and epilepsy. At the cellular level, lifelong nanoplastic exposure caused lysosomal dysfunctions and increased lipofuscin accumulation, indicative of accelerated brain aging. These findings align with the growing prevalence of ADHD and epilepsy in humans, particularly children and the elderly, emphasizing the urgent need to address plastic pollution and its health implications.

Genetic analysis of two bladder exstrophy populations of South Asian and North American origin

INTRODUCTION

Bladder exstrophy-epispadias complex (BEEC) is a devastating congenital anomaly of the urinary tract and is associated with an increased risk of bladder cancer. The etiology of the BEEC is unknown, but a clear genetic component has been highlighted. Currently, all genetic studies suffer from small populations, limited to a European background.

OBJECTIVES

To identify copy number variations (CNVs) in a South Asian and North American bladder exstrophy cohorts. To identify novel non-European CNVs to expand the literature beyond its European ethnic background.

STUDY DESIGN

Patients from our South Asian and North American cohorts had DNA isolated from peripheral blood samples and biobanked at the Children Hospital of Philadelphia's (CHOP) Center for Applied Genomics (CAG). DNA Genotyping was performed with various arrays for the North American cohort and the Illumina Global Screening Array for the South Asian cohort. Controls for both cohorts were identified from CHOP's CAG and ethnicity matching by principle component analysis was performed. CNV calling and filtering were performed with PennCNV and ParseCNV, respectively.

RESULTS

The North American and South Asian cohorts included 53 and 97 patients, respectively. Fifty-five statistically significant CNVs were identified across three independent analyses, of which 53 (96.4 %) were novel to the BE literature. Thirteen of our CNVs were near (within 100 million base pairs) but not in linkage disequilibrium with 8 previously identified BEEC genome-wide association study (GWAS) loci. One of our CNVs (chr16: 28,635,133-28,636,902) was near a previously reported CNV of clinical significance (chr16:29,645,396-30,168,276). Seventeen CNVs contained 15 distinct genes associated with cancer, of which 10/15 (66.7 %) have reported associations in bladder cancer.

DISCUSSION

We present the first genetic analysis of a non-European cohort of bladder exstrophy patients. Our study identified a high number of novel CNVs containing cancer predisposition genes mostly distinct from those found in European cohorts. Limitations inherent to BEEC research include small sample sizes which required intermixing of all phenotypes of the BEEC spectrum (epispadias to cloacal exstrophy). These data highlight the importance of multi-institutional and international collaboration to create ethnically diverse cohorts and allow for severity-specific genetic analyses of the different phenotypes within the BEEC.

CONCLUSION

We identified novel CNVs with distinct cancer predisposition genes in the first study to expand the BEEC literature beyond its European ethnic background. Additional studies in other non-European cohorts are needed to expand our understanding of the genetic landscape of BEEC.

Phytoconstituents of Hericium erinaceus Exert Benefits for ADHD Conditions by Targeting SLC6A4: Extraction, Spectroscopic Characterization, Phytochemical Screening, In Vitro, and Computational Perspectives

Attention-deficit/hyperactivity disorder (ADHD) is a persistent neurodevelopmental disorder. Despite pharmacological interventions, there is a need for effective lead molecules and therapeutic targets. Recently, Hericium erinaceus (HE) has been traditionally reported to treat various diseases. Herein, we aimed to explore the noncytotoxic properties, phytochemical composition, and spectroscopic characterization of HE aqueous extract. Additionally, we used computational workflows to identify key therapeutic targets for ADHD and assess HE extract phytoconstituents for potential targeting. Initially, the HE aqueous extract was obtained using Soxhlet extraction, and its cytotoxicity was assessed on SH-SY5Y cells using MTT assays. FTIR spectroscopy characterized the extract's functional groups, while biochemical methods and GC-MS identified its phytochemical constituents. A protein-protein interaction network identified ADHD targets, and molecular docking, dynamics, and QM/MM calculations were used to find potential drug candidates from the HE extract. As a result, the HE extract exhibited no cytotoxicity in SH-SY5Y cells across concentrations (0.625 to 10 μg/mL) after 24 h. FTIR spectroscopic analysis detected 13 different functional groups that hold diverse biological importance. Qualitative phytochemical screening revealed the presence of carbohydrates, flavonoids, anthocyanins, tannins, alkaloids, saponins, steroids, and phenolic compounds. GC-MS profiling identified 17 diverse metabolites. Simultaneously, ADHD-related genes and known therapeutic protein targets were integrated into a network, identifying SLC6A4 as a hub target. Molecular docking of HE extract compounds showed myo-inositol's high binding efficiency (-6.53 kcal/mol). Dynamic simulations demonstrated stable interactions, and QM/MM analysis confirmed myo-inositol's ability to transfer electrons, reinforcing its interaction potential. Overall, the HE aqueous extract shows a potent nontoxic profile and contains phytoconstituents like myo-inositol, offering promising therapeutic potential by targeting SLC6A4 for ADHD.

Aberrant glutamatergic systems underlying impulsive behaviors: Insights from clinical and preclinical research

Impulsivity is a broad construct that often refers to one of several distinct behaviors and can be measured with self-report questionnaires and behavioral paradigms. Several psychiatric conditions are characterized by one or more forms of impulsive behavior, most notably the impulsive/hyperactive subtype of attention-deficit/hyperactivity disorder (ADHD), mood disorders, and substance use disorders. Monoaminergic neurotransmitters are known to mediate impulsive behaviors and are implicated in various psychiatric conditions. However, growing evidence suggests that glutamate, the major excitatory neurotransmitter of the mammalian brain, regulates important functions that become dysregulated in conditions like ADHD. The purpose of the current review is to discuss clinical and preclinical evidence linking glutamate to separate aspects of impulsivity, specifically motor impulsivity, impulsive choice, and affective impulsivity. Hyperactive glutamatergic activity in the corticostriatal and the cerebro-cerebellar pathways are major determinants of motor impulsivity. Conversely, hypoactive glutamatergic activity in frontal cortical areas and hippocampus and hyperactive glutamatergic activity in anterior cingulate cortex and nucleus accumbens mediate impulsive choice. Affective impulsivity is controlled by similar glutamatergic dysfunction observed for motor impulsivity, except a hyperactive limbic system is also involved. Loss of glutamate homeostasis in prefrontal and nucleus accumbens may contribute to motor impulsivity/affective impulsivity and impulsive choice, respectively. These results are important as they can lead to novel treatments for those with a condition characterized by increased impulsivity that are resistant to conventional treatments.

Novel pharmacological targets for GABAergic dysfunction in ADHD

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopment disorder that affects approximately 5% of the population. The disorder is characterized by impulsivity, hyperactivity, and deficits in attention and cognition, although symptoms vary across patients due to the heterogenous and polygenic nature of the disorder. Stimulant medications are the standard of care treatment for ADHD patients, and their effectiveness has led to the dopaminergic hypothesis of ADHD in which deficits in dopaminergic signaling, especially in cortical brain regions, mechanistically underly ADHD pathophysiology. Despite their effectiveness in many individuals, almost one-third of patients do not respond to stimulant treatments and the long-term negative side effects of these medications remain unclear. Emerging clinical evidence is beginning to highlight an important role of dysregulated excitatory/inhibitory (E/I) balance in ADHD. These deficits in E/I balance are related to functional abnormalities in glutamate and Gamma-Aminobutyric Acid (GABA) signaling in the brain, with increasing emphasis placed on GABAergic interneurons driving specific aspects of ADHD pathophysiology. Recent genome-wide association studies (GWAS) have also highlighted how genes associated with GABA function are mutated in human populations with ADHD, resulting in the generation of several new genetic mouse models of ADHD. This review will discuss how GABAergic dysfunction underlies ADHD pathophysiology, and how specific receptors/proteins related to GABAergic interneuron dysfunction may be pharmacologically targeted to treat ADHD in subpopulations with specific comorbidities and symptom domains. This article is part of the Special Issue on "PFC circuit function in psychiatric disease and relevant models".

Association of ABCA13 Gene Variants with Autism Spectrum Disorder and Other Neuropsychiatric Disorders

Introduction

Autism spectrum disorder (ASD) is a neuropsychiatric disorder characterized by impaired social skills and limited or repetitive behaviors. In this study, we investigated the role of the ABCA13 gene in the etiopathogenesis of ASD.

Methods

Single-nucleotide variants were evaluated in 79 ASD patients (59 males +20 females) with no established genetic etiology associated with ASD using whole-exome sequencing/clinical exome sequencing method. Family segregation analysis was performed using Sanger sequencing. We presented the clinical and genetic findings of these cases and their parents in detail.

Results

We presented 10 different ABCA13 gene variants in cases with ASD and 10 parents carrying the same ABCA13 gene variant. There of these variants were likely pathogenic and seven variants were classified as variant of uncertain significance. Our cases had a comorbidity rate for attention deficit hyperactivity disorder (ADHD) as 70%. Various types of neuropsychiatric symptoms and diagnoses were detected including ADHD, anxiety disorder, intellectual disability, delay in speech, and febrile convulsion among the parents.

Conclusion

To date, very few variants have been reported in the ABCA13 gene. Our findings enrich the role of ABCA13 gene may play a common role in the landscape of neuropsychiatric disorders.