Neuronal Cell Adhesion Molecules May Mediate Neuroinflammation in Autism Spectrum Disorder

Exploring the molecular mechanisms of asthma across multiple datasets

BACKGROUND

Asthma, a prevalent chronic respiratory disorder, remains enigmatic, notwithstanding considerable advancements in our comprehension. Continuous efforts are crucial for discovering novel molecular targets and gaining a comprehensive understanding of its pathogenesis.

MATERIALS AND METHODS

In this study, we analyzed gene expression data from 212 individuals, including asthma patients and healthy controls, to identify 267 differentially expressed genes, among which C1orf64 and C7orf26 emerged as potential key genes in asthma pathogenesis. Various bioinformatics tools, including differential gene expression analysis, pathway enrichment, drug target prediction, and single-cell analysis, were employed to explore the potential roles of the genes.

RESULTS

Quantitative PCR demonstrated differential expression of C1orf64 and C7orf26 in the asthmatic airway epithelial tissue, implying their potential involvement in asthma pathogenesis. GSEA enrichment analysis revealed significant enrichment of these genes in signaling pathways associated with asthma progression, such as ABC transporters, cell cycle, CAMs, DNA replication, and the Notch signaling pathway. Drug target prediction, based on upregulated and downregulated differential expression, highlighted potential asthma treatments, including Tyrphostin-AG-126, Cephalin, Verrucarin-a, and Emetine. The selection of these drugs was based on their significance in the analysis and their established anti-inflammatory and antiviral invasion properties. Utilizing Seurat and Celldex packages for single-cell sequencing analysis unveiled disease-specific gene expression patterns and cell types. Expression of C1orf64 and C7orf26 in T cells, NK cells, and B cells, instrumental in promoting hallmark features of asthma, was observed, suggesting their potential influence on asthma development and progression.

CONCLUSION

This study uncovers novel genetic aspects of asthma, highlighting potential therapeutic pathways. It exemplifies the power of integrative bioinformatics in decoding complex disease patterns. However, these findings require further validation, and the precise roles of C1orf64 and C7orf26 in asthma warrant additional investigation to validate their therapeutic potential.

Transcriptome analysis identifies an ASD-Like phenotype in oligodendrocytes and microglia from C58/J amygdala that is dependent on sex and sociability

BACKGROUND

Autism Spectrum Disorder (ASD) is a group of neurodevelopmental disorders with higher incidence in males and is characterized by atypical verbal/nonverbal communication, restricted interests that can be accompanied by repetitive behavior, and disturbances in social behavior. This study investigated brain mechanisms that contribute to sociability deficits and sex differences in an ASD animal model.

METHODS

Sociability was measured in C58/J and C57BL/6J mice using the 3-chamber social choice test. Bulk RNA-Seq and snRNA-Seq identified transcriptional changes in C58/J and C57BL/6J amygdala within which DMRseq was used to measure differentially methylated regions in amygdala.

RESULTS

C58/J mice displayed divergent social strata in the 3-chamber test. Transcriptional and pathway signatures revealed immune-related biological processes differ between C58/J and C57BL/6J amygdala. Hypermethylated and hypomethylated genes were identified in C58/J versus C57BL/6J amygdala. snRNA-Seq data in C58/J amygdala identified differential transcriptional signatures within oligodendrocytes and microglia characterized by increased ASD risk gene expression and predicted impaired myelination that was dependent on sex and sociability. RNA velocity, gene regulatory network, and cell communication analysis showed diminished oligodendrocyte/microglia differentiation. Findings were verified using Bulk RNA-Seq and demonstrated oxytocin's beneficial effects on myelin gene expression.

LIMITATIONS

Our findings are significant. However, limitations can be noted. The cellular mechanisms linking reduced oligodendrocyte differentiation and reduced myelination to an ASD phenotype in C58/J mice need further investigation. Additional snRNA-Seq and spatial studies would determine if effects in oligodendrocytes/microglia are unique to amygdala or if this occurs in other brain regions. Oxytocin's effects need further examination to understand its' potential as an ASD therapeutic.

CONCLUSIONS

Our work demonstrates the C58/J mouse model's utility in evaluating the influence of sex and sociability on the transcriptome in concomitant brain regions involved in ASD. Our single-nucleus transcriptome analysis elucidates potential pathological roles of oligodendrocytes and microglia in ASD. This investigation provides details regarding regulatory features disrupted in these cell types, including transcriptional gene dysregulation, aberrant cell differentiation, altered gene regulatory networks, and changes to key pathways that promote microglia/oligodendrocyte differentiation. Our studies provide insight into interactions between genetic risk and epigenetic processes associated with divergent affiliative behavior and lack of positive sociability.

Independent and combined effects of astaxanthin and omega-3 on behavioral deficits and molecular changes in a prenatal valproic acid model of autism in rats

Objectives: Autism is a devastating neurodevelopmental disorder and recent studies showed that omega-3 or astaxanthin might reduce autistic symptoms due to their anti-inflammatory properties. Therefore, we investigated the effects of omega-3 and astaxanthin on the VPA-induced autism model of rats.Material and Methods: Female Wistar albino pups (n = 40) were grouped as control, autistic, astaxanthin (2 mg/kg), omega-3 (200 mg/kg), and astaxanthin (2 mg/kg)+omega-3 (200 mg/kg). All groups except the control were prenatally exposed to VPA. Astaxanthin and omega-3 were orally administered from the postnatal day 41 to 68 and behavioral tests were performed between day 69 and 73. The rats were decapitated 24 h after the behavioral tests and hippocampal and prefrontal cytokines and 5-HT levels were analyzed by ELISA.Results: VPA rats have increased grooming behavior while decreased sociability (SI), social preference index (SPI), discrimination index (DI), and prepulse inhibition (PPI) compared to control. Additionally, IL-1β, IL-6, TNF-α, and IFN-γ levels increased while IL-10 and 5-HT levels decreased in both brain regions. Astaxanthin treatment raised SI, SPI, DI, PPI, and prefrontal IL-10 levels. It also raised 5-HT levels and decreased IL-6 levels in both brain regions. Omega-3 and astaxanthin + omega-3 increased the SI, SPI, DI, and PPI and decreased grooming behavior. Moreover, they increased IL-10 and 5-HT levels whereas decreased IL-1β, IL-6, TNF-α, IFN-γ levels in both brain regions.Conclusions: Our results showed that VPA administration mimicked the behavioral and molecular changes of autism in rats. Single and combined administration of astaxanthin and omega-3 improved the autistic-like behavioral and molecular changes in the VPA model of rats.

Revealing cell-cell communication pathways with their spatially coupled gene programs

Inference of cell-cell communication (CCC) provides valuable information in understanding the mechanisms of many important life processes. With the rise of spatial transcriptomics in recent years, many methods have emerged to predict CCCs using spatial information of cells. However, most existing methods only describe CCCs based on ligand-receptor interactions, but lack the exploration of their upstream/downstream pathways. In this paper, we proposed a new method to infer CCCs, called Intercellular Gene Association Network (IGAN). Specifically, it is for the first time that we can estimate the gene associations/network between two specific single spatially adjacent cells. By using the IGAN method, we can not only infer CCCs in an accurate manner, but also explore the upstream/downstream pathways of ligands/receptors from the network perspective, which are actually exhibited as a new panoramic cell-interaction-pathway graph, and thus provide extensive information for the regulatory mechanisms behind CCCs. In addition, IGAN can measure the CCC activity at single cell/spot resolution, and help to discover the CCC spatial heterogeneity. Interestingly, we found that CCC patterns from IGAN are highly consistent with the spatial microenvironment patterns for each cell type, which further indicated the accuracy of our method. Analyses on several public datasets validated the advantages of IGAN.

Autoimmune nodopathy with anti-contactin 1 antibody characterized by cerebellar dysarthria: a case report and literature review

Background

Autoimmune nodopathy (AN) has emerged as a novel diagnostic category that is pathologically different from classic chronic inflammatory demyelinating polyneuropathy. Clinical manifestations of AN include sensory or motor neuropathies, sensory ataxia, tremor, and cranial nerve involvement. AN with a serum-positive contactin-1 (CNTN1) antibody usually results in peripheral nerve demyelination. In this study, we reported a rare case of AN with CNTN1 antibodies characterized by the presence of CNTN1 antibodies in both serum and cerebrospinal fluid, which is associated with cerebellar dysarthria.

Methods

A 25-year-old man was admitted to our hospital due to progressive dysarthria with limb tremors. The patient was initially diagnosed with peripheral neuropathy at a local hospital. Three years after onset, he was admitted to our hospital due to dysarthria, apparent limb tremor, and limb weakness. At that time, he was diagnosed with spinocerebellar ataxia. Eight years post-onset, during his second admission, his condition had notably deteriorated. His dysarthria had evolved to typical distinctive cerebellar characteristics, such as tremor, loud voice, stress, and interrupted articulation. Additionally, he experienced further progression in limb weakness and developed muscle atrophy in the distal limbs. Magnetic resonance imaging (MRI), nerve conduction studies (NCS), and autoimmune antibody tests were performed.

Results

The results of the NCS suggested severe demyelination and even axonal damage to the peripheral nerves. MRI scans revealed diffuse thickening of bilateral cervical nerve roots, lumbosacral nerve roots, cauda equina nerve, and multiple intercostal nerve root sheath cysts. Furthermore, anti-CNTN1 antibody titers were 1:10 in the cerebrospinal fluid (CSF) and 1:100 in the serum. After one round of rituximab treatment, the patient showed significant improvement in limb weakness and dysarthria, and the CSF antibodies turned negative.

Conclusion

Apart from peripheral neuropathies, cerebellar dysarthria (central nervous system involvement) should not be ignored in AN patients with CNTN1 antibodies.

A network-based method for associating genes with autism spectrum disorder

Autism spectrum disorder (ASD) is a highly heritable complex disease that affects 1% of the population, yet its underlying molecular mechanisms are largely unknown. Here we study the problem of predicting causal genes for ASD by combining genome-scale data with a network propagation approach. We construct a predictor that integrates multiple omic data sets that assess genomic, transcriptomic, proteomic, and phosphoproteomic associations with ASD. In cross validation our predictor yields mean area under the ROC curve of 0.87 and area under the precision-recall curve of 0.89. We further show that it outperforms previous gene-level predictors of autism association. Finally, we show that we can use the model to predict genes associated with Schizophrenia which is known to share genetic components with ASD.

Transcriptome Analysis Identifies An ASD-Like Phenotype In Oligodendrocytes And Microglia From C58/J Amygdala That Is Dependent On Sex and Sociability

Background

Autism Spectrum Disorder (ASD) is a group of neurodevelopmental disorders with higher incidence in males and is characterized by atypical verbal/nonverbal communication, restricted interests that can be accompanied by repetitive behavior, and disturbances in social behavior. This study investigated brain mechanisms that contribute to sociability deficits and sex differences in an ASD animal model.

Methods

Sociability was measured in C58/J and C57BL/6J mice using the 3-chamber social choice test. Bulk RNA-Seq and snRNA-Seq identified transcriptional changes in C58/J and C57BL/6J amygdala within which DMRseq was used to measure differentially methylated regions in amygdala.

Results

C58/J mice displayed divergent social strata in the 3-chamber test. Transcriptional and pathway signatures revealed immune-related biological processes differ between C58/J and C57BL/6J amygdala. Hypermethylated and hypomethylated genes were identified in C58/J versus C57BL/6J amygdala. snRNA-Seq data in C58/J amygdala identified differential transcriptional signatures within oligodendrocytes and microglia characterized by increased ASD risk gene expression and predicted impaired myelination that was dependent on sex and sociability. RNA velocity, gene regulatory network, and cell communication analysis showed diminished oligodendrocyte/microglia differentiation. Findings were verified using bulk RNA-Seq and demonstrated oxytocin's beneficial effects on myelin gene expression.

Limitations

Our findings are significant. However, limitations can be noted. The cellular mechanisms linking reduced oligodendrocyte differentiation and reduced myelination to an ASD phenotype in C58/J mice need further investigation. Additional snRNA-Seq and spatial studies would determine if effects in oligodendrocytes/microglia are unique to amygdala or if this occurs in other brain regions. Oxytocin's effects need further examination to understand its potential as an ASD therapeutic.

Conclusions

Our work demonstrates the C58/J mouse model's utility in evaluating the influence of sex and sociability on the transcriptome in concomitant brain regions involved in ASD. Our single-nucleus transcriptome analysis elucidates potential pathological roles of oligodendrocytes and microglia in ASD. This investigation provides details regarding regulatory features disrupted in these cell types, including transcriptional gene dysregulation, aberrant cell differentiation, altered gene regulatory networks, and changes to key pathways that promote microglia/oligodendrocyte differentiation. Our studies provide insight into interactions between genetic risk and epigenetic processes associated with divergent affiliative behavior and lack of positive sociability.

Causal relationships between atopic dermatitis and psychiatric disorders: a bidirectional two-sample Mendelian randomization study

BACKGROUND

Observational studies have suggested the potential associations between atopic dermatitis (AD) and psychiatric disorders. However, the causal relationship between them remains uncertain. This study aimed to evaluate the potential bidirectional causal relationship between AD and psychiatric disorders, including autism spectrum disorder (ASD), major depressive disorder (MDD), attention deficit hyperactivity disorder (ADHD), bipolar disorder (BD), anorexia nervosa (AN), Tourette syndrome (TS), schizophrenia, and anxiety.

METHODS

Bidirectional two-sample Mendelian randomization (MR) was employed to elucidate the causality between AD and psychiatric disorders, using summary statistics from the most comprehensive genome-wide association studies conducted on AD (Ncases = 60,653, Ncontrols = 804,329). Psychiatric disorders were derived from the Psychiatric Genomics Consortium and were independent of AD data sources. The MR analysis entailed the implementation of multiple methods, including the inverse variance weighted method, MR-Egger regression method, weighted median method, simple mode method, and weighted mode method.

RESULTS

Bidirectional two-sample MR analysis uncovered significant causal associations between AD and severe psychiatric disorders. Specifically, liability to AD was associated with increased risk of ADHD (OR = 1.116; 95% CI: [1.009, 1.234]; P = 0.033) and ASD (OR = 1.131; 95% CI: [1.023, 1.251]; P = 0.016). Additionally, evidence suggested that liability to ADHD (OR = 1.112; 95% CI: [1.094, 1.130]; P = 9.20e-40), liability to AN (OR = 1.1; 95% CI: [1.068, 1.134]; P = 4.45e-10) and liability to BD (OR = 1.067; 95% CI: [1.009, 1.128]; P = 0.023) were associated with an increased risk of AD. Only the causal association between AD and ASD was independent of the reverse effect bias. These causal associations were robust and not affected by biases of heterogeneity and horizontal pleiotropy.

CONCLUSIONS

Our study emphasizes the significant causal association between AD and an increased risk of ASD, and also identifying BD and AN as risk factors for AD.

Bell's palsy was associated with TRPV2 downregulation of Schwann cell by cold stress

OBJECTIVE

Epidemiological and clinical studies have shown that sharp changes in the ambient temperature are associated with the occurrence and development of Bell's palsy. However, the specific pathogenesis of peripheral facial paralysis remains nebulous. This study investigated the effect of cold stress on transient receptor potential cation channel subfamily V member 2 (TRPV2) secretion by Schwann cells and its role in Bell's palsy.

MATERIALS AND METHODS

Schwann cell morphology was observed using transmission electron microscopy (TEM). Cell proliferation, apoptosis and cell cycle were analysed using CCK8 and flow cytometry. ELISA, Reverse transcription-quantitative PCR, western blotting and immunocytochemical fluorescence staining were used to detect the effects of cold stress on TRPV2, neural cell adhesion molecule (NCAM) and nerve growth factor (NGF) expression in Schwann cells.

RESULTS

Cold stress resulted in a widening of the intercellular space, and the particles on the membrane showed different degrees of loss. Cold stress may cause Schwann cells to enter a cold dormant state. ELISA, RT-qPCR, western blotting and immunocytochemical fluorescences staining indicated that cold stress inhibited the expression of TRPV2, NCAM, and NGF.

CONCLUSIONS

Drastic temperature difference between cold and heat can downregulate TRPV2 and the secretome of Schwann cells. The imbalance of Schwann cell homeostasis under such stress may contribute to nerve signalling dysfunction leading to the development of facial paralysis.

Serum Neurofilament Light Chain and Glial Fibrillary Acidic Protein as Potential Diagnostic Biomarkers in Autism Spectrum Disorders: A Preliminary Study

Autism spectrum disorder (ASD) is one of the most common neurodevelopment disorders, characterized by a multifactorial etiology based on the interaction of genetic and environmental factors. Recent evidence supports the neurobiological hypothesis based on neuroinflammation theory. To date, there are no sufficiently validated diagnostic and prognostic biomarkers for ASD. Therefore, we decided to investigate the potential diagnostic role for ASD of two biomarkers well known for other neurological inflammatory conditions: the glial fibrillary acidic protein (GFAP) and the neurofilament (Nfl). Nfl and GFAP serum levels were analyzed using SiMoA technology in a group of ASD patients and in a healthy control group (CTRS), age- and gender-matched. Then we investigated the distribution, frequency, and correlation between serum Nfl and GFAP levels and clinical data among the ASD group. The comparison of Nfl and GFAP serum levels between ASD children and the control group showed a mean value of these two markers significantly higher in the ASD group (sNfL mean value ASD pt 6.86 pg/mL median value ASD pt 5.7 pg/mL; mean value CTRS 3.55 pg/mL; median value CTRS 3.1 pg; GFAP mean value ASD pt 205.7 pg/mL median value ASD pt 155.4 pg/mL; mean value CTRS 77.12 pg/mL; median value CTRS 63.94 pg/mL). Interestingly, we also found a statistically significant positive correlation between GFAP levels and hyperactivity symptoms (p-value <0.001). Further investigations using larger groups are necessary to confirm our data and to verify in more depth the potential correlation between these biomarkers and ASD clinical features, such as the severity of the core symptoms, the presence of associated symptoms, and/or the evaluation of a therapeutic intervention. However, these data not only might shed a light on the neurobiology of ASD, supporting the neuroinflammation and neurodegeneration hypothesis, but they also might support the use of these biomarkers in the early diagnosis of ASD, to longitudinally monitor the disease activity, and even more as future prognostic biomarkers.

Is Atopic Dermatitis Only a Skin Disease?

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory dermatosis that imposes significant patient and population burdens. In addition to the cutaneous signs and symptoms, growing evidence suggests that AD is systemic in nature. Certain diseases can possibly co-occur with AD as a result of coincidental exposure to similar environmental factors. However, it is also suspected that they are linked to the pathogenesis of AD through more complex genetic and immunological mechanisms, but these correlations remain less understood. It is of great need to seek explanations for the higher frequency of the number of cardiovascular, autoimmune, neurological, psychiatric, and metabolic disorders that have been observed in epidemiologic investigations among AD patients. Moreover, analysing the immunology of chronic inflammation and its correction, activation, or suppression may prevent the development of a variety of comorbidities. As comorbid diseases in patients diagnosed with AD may potentially go undetected, physicians should be aware of them.

Effect of subchronic exposure to ambient fine and ultrafine particles on rat motor activity and ex vivo striatal dopaminergic transmission

Alterations in dopaminergic transmission are associated with neurological disorders, such as depression, autism, and Parkinson's disease. Exposure of rats to ambient fine (FP) or ultrafine (UFP) particles induces oxidative and inflammatory responses in the striatum, a neuronal nucleus with dense dopaminergic innervation and critically involved in the control of motor activity.Objectives: We used an ex vivo system to evaluate the effect of in vivo inhalation exposure to FP and UFP on motor activity and dopaminergic transmission.Materials and Methods: Male adult Wistar rats were exposed to FP, UFP, or filtered air for 8 weeks (subchronic exposure; 5 h/day, 5 days/week) in a particle concentrator. Motor activity was evaluated using the open-field test. Uptake and release of [³H]-dopamine were assessed in striatal synaptosomes, and dopamine D₂ receptor (D₂R) affinity for dopamine was evaluated by the displacement of [³H]-spiperone binding to striatal membranes.Results: Exposure to FP or UFP significantly reduced spontaneous motor activity (ambulatory distance: FP -25%, UFP -32%; ambulatory time: FP -24%, UFP -22%; ambulatory episodes: FP -22%, UFP -30%), decreased [³H]-dopamine uptake (FP -18%, UFP -24%), and increased, although not significantly, [³H]-dopamine release (113.3 ± 16.3 and 138.6 ± 17.3%). Neither FP nor UFP exposure affected D₂R density or affinity for dopamine.Conclusions: These results indicate that exposure to ambient particulate matter reduces locomotion in rats, which could be related to altered striatal dopaminergic transmission: UFP was more potent than FP. Our results contribute to the evidence linking environmental factors to changes in brain function that could turn into neurological and psychiatric disorders.HIGHLIGHTSYoung adult rats were exposed to fine (FP) or ultrafine (UFP) particles for 40 days.Exposure to FP or UFP reduced motor activity.Exposure to FP or UFP reduced dopamine uptake by striatal synaptosomes.Neither D₂R density or affinity for dopamine was affected by FP or UFP.UFP was more potent than FP to exert the effects reported.