Abnormal melatonin synthesis in autism spectrum disorders

Advances in molecular mechanisms and therapeutic strategies for central nervous system diseases based on gut microbiota imbalance

BACKGROUD

Central nervous system (CNS) diseases pose a serious threat to human health, but the regulatory mechanisms and therapeutic strategies of CNS diseases need to be further explored. It has been demonstrated that the gut microbiota (GM) is closely related to CNS disease. GM structure disorders, abnormal microbial metabolites, intestinal barrier destruction and elevated inflammation exist in patients with CNS diseases and promote the development of CNS diseases. More importantly, GM remodeling alleviates CNS pathology to some extent.

AIM OF REVIEW

Here, we have summarized the regulatory mechanism of the GM in CNS diseases and the potential treatment strategies for CNS repair based on GM regulation, aiming to provide safer and more effective strategies for CNS repair from the perspective of GM regulation.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The abundance and composition of GM is closely associated with the CNS diseases. On the basis of in-depth analysis of GM changes in mice with CNS disease, as well as the changes in its metabolites, therapeutic strategies, such as probiotics, prebiotics, and FMT, may be used to regulate GM balance and affect its microbial metabolites, thereby promoting the recovery of CNS diseases.

The impact of the physical activity intervention on sleep in children and adolescents with autism spectrum disorder: A systematic review and meta-analysis

Pharmacological treatments (i.e., melatonin) and non-pharmacological therapies (e.g., parent-based sleep education programs and behavioural interventions) have been found to result in improved sleep in children and adolescents with autism spectrum disorder (ASD). However, there are several limitations to these treatment approaches, including concerns about the possible side-effects and safety, high-cost and uncertainties of long-term effects. Physical activity (PA) intervention is a promising behavioural intervention that has received increasing attention. However, the effects of PA intervention on sleep are still unclear in this clinical group. This study aimed to synthesize available empirical studies concerning the effects of PA interventions on sleep in children and adolescents with ASD. Following PRISMA guidelines, seven electronic databases: APA PsychInfo, CINAHL Ultimate, ERIC, MEDLINE, PubMed, SPORTDiscus, and Web of Science, were searched from inception to March 2023. Randomized controlled trials/quasi-experimental designs with comparison groups were included. Initially, 444 articles were identified, 13 articles underwent systematic review, and 8 studies with control groups and sufficient statistical data were selected for meta-analysis. Compared to no-treatment control groups, PA interventions had a large positive effect on parent-reported general sleep problems, night awakenings, sleep resistance, sleep duration and actigraphy-assessed sleep efficiency in children and adolescents with ASD.

Contribution of the serotonergic system to developmental brain abnormalities in autism spectrum disorder

This review highlights a key role of the serotonergic system in brain development and in distortions of normal brain development in early stages of fetal life resulting in cascades of abnormalities, including defects of neurogenesis, neuronal migration, neuronal growth, differentiation, and arborization, as well as defective neuronal circuit formation in the cortex, subcortical structures, brainstem, and cerebellum of autistic subjects. In autism, defects in regulation of neuronal growth are the most frequent and ubiquitous developmental changes associated with impaired neuron differentiation, smaller size, distorted shape, loss of spatial orientation, and distortion of cortex organization. Common developmental defects of the brain in autism include multiregional focal dysplastic changes contributing to local neuronal circuit distortion, epileptogenic activity, and epilepsy. There is a discrepancy between more than 500 reports demonstrating the contribution of the serotonergic system to autism's behavioral anomalies, highlighted by lack of studies of autistic subjects' brainstem raphe nuclei, the center of brain serotonergic innervation, and of the contribution of the serotonergic system to the diagnostic features of autism spectrum disorder (ASD). Discovery of severe fetal brainstem auditory system neuronal deficits and other anomalies leading to a spectrum of hearing deficits contributing to a cascade of behavioral alterations, including deficits of social and verbal communication in individuals with autism, is another argument to intensify postmortem studies of the type and topography of, and the severity of developmental defects in raphe nuclei and their contribution to abnormal brain development and to the broad spectrum of functional deficits and comorbid conditions in ASD.

Autism Spectrum Disorder and Sleep

Children and adolescents with autism spectrum disorder (ASD) experience sleep disturbances, particularly insomnia, at rates much higher than the general population. Daytime behavioral problems and parental stress are associated with the resultant sleep deprivation. Behavioral interventions, parental education, and melatonin are effective treatments. The epidemiology of sleep disturbances in youth with ASD is reviewed in this article as well as the latest in treatments.

Restless sleep disorder in a sample of children and adolescents with autism spectrum disorder: preliminary results from a case series

STUDY OBJECTIVES

Sleep disorders are a frequent comorbidity among children with autism spectrum disorder (ASD). Among sleep-related issues of ASD, restless sleep is a common complaint. In recent years, restless sleep disorder (RSD) has been proposed as a new clinical entity, characterized by agitated sleep as its predominant manifestation. Despite the high prevalence of sleep disorders and data reporting restless sleep among ASD patients, to date no study has yet characterized RSD within patients with ASD. Therefore, the aim of our study was to assess the occurrence of RSD in a sample of children and adolescents with ASD through clinical and polysomnographic assessment.

METHODS

Children and adolescents with ASD ages 6-18 years were recruited for the study. Through parental interviews, patients with a suspected RSD were selected and offered diagnostic investigation by video-polysomnography and blood tests to assess martial balance.

RESULTS

Among the 129 participants included, 16 patients (12.4%) were found to have a suspected RSD. Only 6 (4.7%) underwent video-polysomnography due to lack of compliance or family refusal. In 6/6 participants examined, the disorder was confirmed by video-polysomnography movement analysis (total movement index ≥ 5 events/h) and ferritin values were found in the normal range.

CONCLUSIONS

RSD does not appear to be particularly frequent among patients with ASD and that of iron metabolism may not be the main factor implicated in the pathogenesis of RSD within this population. Additional evaluation is needed to confirm the result and further investigate the etiological mechanisms underlying the disorder.

CITATION

Voci A, Mazzone L, De Stefano D, Valeriani M, Bruni O, Moavero R. Restless sleep disorder in a sample of children and adolescents with autism spectrum disorder: preliminary results from a case series. J Clin Sleep Med. 2024;20(3):427-432.

Sleep problems in children with autism spectrum disorder and attention-deficit/hyperactivity disorder: A comparative study and effects on communication skills

Sleep disturbances are highly prevalent among children with neurodevelopmental disorders, like Autism Spectrum Disorder (ASD) and Attention-Deficit/Hiperactivity Disorder (ADHD). The first objective of this study is to examine the differences in sleep problems between a group of children with ASD without intellectual disabilities, a group with ADHD and a typically developing (TD) group. A second objective is aimed at analyzing the effects of sleep problems and symptom severity on their communication skills. Participants were 122 children between 7 and 12 years old distributed in three groups: 32 TD children, 47 children with ASD and 43 children with ADHD, matched on age and intelligence. Parents completed different questionnaires that measured sleep disturbances and communication skills. Findings show significant differences between the clinical groups and the TD group in most types of sleep disorders. Moreover, the group with ADHD showed significantly more sleep breathing disorders and hyperhidrosis in comparison with ASD and TD, as well as more total sleep problems. In contrast to ASD, the predictive power of sleep problems on communication difficulties was greater in the group with ADHD. The results of the mediation analysis indicate that in both groups, sleep problems partially mediate the relationship between symptoms and communication. This investigation highlights the need of considering sleep disorders when assessing communication skills in ASD and ADHD, given its indirect influence in this domain. Understanding the sleep dysfunctions of both conditions and their repercussions is crucial to develop adjusted interventions.

Ratiometric fluorescent sensing of melatonin based on inner filter effect and smartphone established detection

Melatonin (MLT) is a crucial neurohormone having inhibitory effects over various types of cancer. In this work, 3,6-Diaminocarbazole (DAC), a fluorescent probe is utilized to detect MLT in a highly sensitive, selective and facile way. The unique feature of present work is that MLT is sensed by ratiometric fluorescent technique based on the inner filter effect (IFE) using DAC at an emission wavelength of 310 nm. As a result, a noticeable change in color from red to cyan is observed and the quantitative analysis of fluorescence signals at these wavelengths are used to detect MLT observing a linear relationship between the ratio of emission intensities and the concentration of MLT over a linear range of 0 to 78 μM. DAC can accurately measure the detailed quantity of MLT with a limit of detection of 30 nM and has proved to be an efficient sensing probe due to its excellent molar absorptivity and high photoluminescence quantum yield (PLQY). Sensing characterization was carried out UV-Vis, steady-state, and time- resolved fluorescence spectroscopic techniques. The smartphone app "RGB colour detector" value has been successfully linked with the considerable detectable color changes of DAC on addition of MLT. HOMO-LUMO have been calculated using DFT with B3LYP/6-31G(d,p) level and band gaps of 3.77 eV and 4.91 eV were found for DAC and MLT, respectively. Electrons are not allowed energetically to transfer from MLT to DAC, as is evident from their band gaps. Therefore, IFE can be considered the foremost method in fluorescence quenching of present investigation. The developed sensor was verified by spiking of MLT in human serum.

Melatonin as a Mediator of the Gut Microbiota-Host Interaction: Implications for Health and Disease

In recent years, the role played by melatonin on the gut microbiota has gained increasingly greater attention. Additionally, the gut microbiota has been proposed as an alternative source of melatonin, suggesting that this antioxidant indoleamine could act as a sort of messenger between the gut microbiota and the host. This review analyses the available scientific literature about possible mechanisms involved in this mediating role, highlighting its antioxidant effects and influence on this interaction. In addition, we also review the available knowledge on the effects of melatonin on gut microbiota composition, as well as its ability to alleviate dysbiosis related to sleep deprivation or chronodisruptive conditions. The melatonin-gut microbiota relationship has also been discussed in terms of its role in the development of different disorders, from inflammatory or metabolic disorders to psychiatric and neurological conditions, also considering oxidative stress and the reactive oxygen species-scavenging properties of melatonin as the main factors mediating this relationship.

Neural EGFL-like 1, a craniosynostosis-related osteochondrogenic molecule, strikingly associates with neurodevelopmental pathologies

Various craniofacial syndromes cause skeletal malformations and are accompanied by neurological abnormalities at different levels, leading to tremendous biomedical, financial, social, and psychological burdens. Accumulating evidence highlights the importance of identifying and characterizing the genetic basis that synchronously modulates musculoskeletal and neurobehavioral development and function. Particularly, previous studies from different groups have suggested that neural EGFL-like-1 (Nell-1), a well-established osteochondrogenic inducer whose biopotency was initially identified in the craniofacial tissues, may also play a vital role in the central nervous system, particularly regarding neurological disorder pathologies. To provide first-hand behavior evidence if Nell-1 also has a role in central nervous system abnormalities, we compared the Nell-1-haploinsufficient (Nell-1+/6R) mice with their wild-type counterparts regarding their repetitive, social communication, anxiety-related, locomotor, sensory processing-related, motor coordination, and Pavlovian learning and memory behaviors, as well as their hippocampus transcriptional profile. Interestingly, Nell-1+/6R mice demonstrated core autism spectrum disorder-like deficits, which could be corrected by Risperidone, an FDA-approved anti-autism, anti-bipolar medicine. Besides, transcriptomic analyses identified 269 differential expressed genes, as well as significantly shifted alternative splicing of ubiquitin B pseudogene Gm1821, in the Nell-1+/6R mouse hippocampus, which confirmed that Nell-1 plays a role in neurodevelopment. Therefore, the current study verifies that Nell-1 regulates neurological development and function for the first time. Moreover, this study opens new avenues for understanding and treating craniofacial patients suffering from skeletal deformities and behavior, memory, and cognition difficulties by uncovering a novel bone-brain-crosstalk network. Furthermore, the transcriptomic analysis provides the first insight into deciphering the mechanism of Nell-1 in neurodevelopment.

Impact of IDO activation and alterations in the kynurenine pathway on hyperserotonemia, NAD+ production, and AhR activation in autism spectrum disorder

Hyperserotonemia is the most replicated biochemical anomaly associated with autism spectrum disorder (ASD) and has been reported in 35-46% of individuals with ASD. Serotonin is synthesised from the essential amino acid tryptophan (TRP). However, the main catabolic route of TRP is the kynurenine pathway (KP), which competes with serotonin synthesis when indoleamine dioxygenase (IDO) is activated. Using the same cohort of individuals with ASD, we used to report extensive studies of the serotonin/melatonin pathway, and found increased kynurenine (KYN), suggesting IDO activation in 58.7% of individuals with ASD (159/271), supported by a strong negative correlation between KYN/TRP ratio and miR-153-3p plasma levels, which negatively regulates IDO. IDO activation was associated with normoserotonemia, suggesting that IDO activation could mask hyperserotonemia which meant that hyperserotonemia, if not masked by IDO activation, could be present in ~94% of individuals with ASD. We also identified several KP alterations, independent of IDO status. We observed a decrease in the activity of 3-hydroxyanthranilate dioxygenase which translated into the accumulation of the aryl hydrocarbon receptor (AhR) selective ligand cinnabarinic acid, itself strongly positively correlated with the AhR target stanniocalcin 2. We also found a deficit in NAD+ production, the end-product of the KP, which was strongly correlated with plasma levels of oxytocin used as a stereotypical neuropeptide, indicating that regulated neuropeptide secretion could be limiting. These results strongly suggest that individuals with ASD exhibit low-grade chronic inflammation that is mediated in most cases by chronic AhR activation that could be associated with the highly prevalent gastrointestinal disorders observed in ASD, and explained IDO activation in ~58% of the cases. Taken together, these results extend biochemical anomalies of TRP catabolism to KP and posit TRP catabolism as a possible major component of ASD pathophysiology.

RatDEGdb: a knowledge base of differentially expressed genes in the rat as a model object in biomedical research

The animal models used in biomedical research cover virtually every human disease. RatDEGdb, a knowledge base of the differentially expressed genes (DEGs) of the rat as a model object in biomedical research is a collection of published data on gene expression in rat strains simulating arterial hypertension, age-related diseases, psychopathological conditions and other human afflictions. The current release contains information on 25,101 DEGs representing 14,320 unique rat genes that change transcription levels in 21 tissues of 10 genetic rat strains used as models of 11 human diseases based on 45 original scientific papers. RatDEGdb is novel in that, unlike any other biomedical database, it offers the manually curated annotations of DEGs in model rats with the use of independent clinical data on equal changes in the expression of homologous genes revealed in people with pathologies. The rat DEGs put in RatDEGdb were annotated with equal changes in the expression of their human homologs in affected people. In its current release, RatDEGdb contains 94,873 such annotations for 321 human genes in 836 diseases based on 959 original scientific papers found in the current PubMed. RatDEGdb may be interesting first of all to human geneticists, molecular biologists, clinical physicians, genetic advisors as well as experts in biopharmaceutics, bioinformatics and personalized genomics. RatDEGdb is publicly available at https://www.sysbio.ru/RatDEGdb.

Endophenotype trait domains for advancing gene discovery in autism spectrum disorder

Autism spectrum disorder (ASD) is associated with a diverse range of etiological processes, including both genetic and non-genetic causes. For a plurality of individuals with ASD, it is likely that the primary causes involve multiple common inherited variants that individually account for only small levels of variation in phenotypic outcomes. This genetic landscape creates a major challenge for detecting small but important pathogenic effects associated with ASD. To address similar challenges, separate fields of medicine have identified endophenotypes, or discrete, quantitative traits that reflect genetic likelihood for a particular clinical condition and leveraged the study of these traits to map polygenic mechanisms and advance more personalized therapeutic strategies for complex diseases. Endophenotypes represent a distinct class of biomarkers useful for understanding genetic contributions to psychiatric and developmental disorders because they are embedded within the causal chain between genotype and clinical phenotype, and they are more proximal to the action of the gene(s) than behavioral traits. Despite their demonstrated power for guiding new understanding of complex genetic structures of clinical conditions, few endophenotypes associated with ASD have been identified and integrated into family genetic studies. In this review, we argue that advancing knowledge of the complex pathogenic processes that contribute to ASD can be accelerated by refocusing attention toward identifying endophenotypic traits reflective of inherited mechanisms. This pivot requires renewed emphasis on study designs with measurement of familial co-variation including infant sibling studies, family trio and quad designs, and analysis of monozygotic and dizygotic twin concordance for select trait dimensions. We also emphasize that clarification of endophenotypic traits necessarily will involve integration of transdiagnostic approaches as candidate traits likely reflect liability for multiple clinical conditions and often are agnostic to diagnostic boundaries. Multiple candidate endophenotypes associated with ASD likelihood are described, and we propose a new focus on the analysis of "endophenotype trait domains" (ETDs), or traits measured across multiple levels (e.g., molecular, cellular, neural system, neuropsychological) along the causal pathway from genes to behavior. To inform our central argument for research efforts toward ETD discovery, we first provide a brief review of the concept of endophenotypes and their application to psychiatry. Next, we highlight key criteria for determining the value of candidate endophenotypes, including unique considerations for the study of ASD. Descriptions of different study designs for assessing endophenotypes in ASD research then are offered, including analysis of how select patterns of results may help prioritize candidate traits in future research. We also present multiple candidate ETDs that collectively cover a breadth of clinical phenomena associated with ASD, including social, language/communication, cognitive control, and sensorimotor processes. These ETDs are described because they represent promising targets for gene discovery related to clinical autistic traits, and they serve as models for analysis of separate candidate domains that may inform understanding of inherited etiological processes associated with ASD as well as overlapping neurodevelopmental disorders.

Circadian Regulation of the Neuroimmune Environment Across the Lifespan: From Brain Development to Aging

Circadian clocks confer 24-h periodicity to biological systems, to ultimately maximize energy efficiency and promote survival in a world with regular environmental light cycles. In mammals, circadian rhythms regulate myriad physiological functions, including the immune, endocrine, and central nervous systems. Within the central nervous system, specialized glial cells such as astrocytes and microglia survey and maintain the neuroimmune environment. The contributions of these neuroimmune cells to both homeostatic and pathogenic demands vary greatly across the day. Moreover, the function of these cells changes across the lifespan. In this review, we discuss circadian regulation of the neuroimmune environment across the lifespan, with a focus on microglia and astrocytes. Circadian rhythms emerge in early life concurrent with neuroimmune sculpting of brain circuits and wane late in life alongside increasing immunosenescence and neurodegeneration. Importantly, circadian dysregulation can alter immune function, which may contribute to susceptibility to neurodevelopmental and neurodegenerative diseases. In this review, we highlight circadian neuroimmune interactions across the lifespan and share evidence that circadian dysregulation within the neuroimmune system may be a critical component in human neurodevelopmental and neurodegenerative diseases.

SOX7: Novel Autistic Gene Identified by Analysis of Multi-Omics Data

Background

Genome-wide association studies and next generation sequencing data analyses based on DNA information have identified thousands of mutations associated with autism spectrum disorder (ASD). However, more than 99% of identified mutations are non-coding. Thus, it is unclear which of these mutations might be functional and thus potentially causal variants. Transcriptomic profiling using total RNA-sequencing has been one of the most utilized approaches to link protein levels to genetic information at the molecular level. The transcriptome captures molecular genomic complexity that the DNA sequence solely does not. Some mutations alter a gene's DNA sequence but do not necessarily change expression and/or protein function. To date, few common variants reliably associated with the diagnosis status of ASD despite consistently high estimates of heritability. In addition, reliable biomarkers used to diagnose ASD or molecular mechanisms to define the severity of ASD do not exist.

Objectives

It is necessary to integrate DNA and RNA testing together to identify true causal genes and propose useful biomarkers for ASD.

Methods

We performed gene-based association studies with adaptive test using genome-wide association studies (GWAS) summary statistics with two large GWAS datasets (ASD 2019 data: 18,382 ASD cases and 27,969 controls [discovery data]; ASD 2017 data: 6,197 ASD cases and 7,377 controls [replication data]) which were obtained from the Psychiatric Genomics Consortium (PGC). In addition, we investigated differential expression for genes identified in gene-based GWAS with a RNA-seq dataset (GSE30573: 3 cases and 3 controls) using the DESeq2 package.

Results

We identified 5 genes significantly associated with ASD in ASD 2019 data (KIZ-AS1, p=8.67×10-10; KIZ, p=1.16×10-9; XRN2, p=7.73×10-9; SOX7, p=2.22×10-7; PINX1-DT, p=2.14×10-6). Among these 5 genes, gene SOX7 (p=0.00087), LOC101929229 (p=0.009), and KIZ-AS1 (p=0.059) were replicated in ASD 2017 data. KIZ (p=0.06) was close to the boundary of replication in ASD 2017 data. Genes SOX7 (p=0.0017, adjusted p=0.0085), LOC101929229 (also known as PINX1-DT, p=5.83×10-7, adjusted p=1.18×10-5), and KIZ (p=0.00099, adjusted p=0.0055) indicated significant expression differences between cases and controls in the RNA-seq data. SOX7 encodes a member of the SOX (SRY-related HMG-box) family of transcription factors pivotally contributing to determining of the cell fate and identity in many lineages. The encoded protein may act as a transcriptional regulator after forming a protein complex with other proteins leading to autism.

Conclusion

Gene SOX7 in the transcription factor family could be associated with ASD. This finding may provide new diagnostic and therapeutic strategies for ASD.

Sleep disturbances in autism spectrum disorder: Animal models, neural mechanisms, and therapeutics

Sleep is crucial for brain development. Sleep disturbances are prevalent in children with autism spectrum disorder (ASD). Strikingly, these sleep problems are positively correlated with the severity of ASD core symptoms such as deficits in social skills and stereotypic behavior, indicating that sleep problems and the behavioral characteristics of ASD may be related. In this review, we will discuss sleep disturbances in children with ASD and highlight mouse models to study sleep disturbances and behavioral phenotypes in ASD. In addition, we will review neuromodulators controlling sleep and wakefulness and how these neuromodulatory systems are disrupted in animal models and patients with ASD. Lastly, we will address how the therapeutic interventions for patients with ASD improve various aspects of sleep. Together, gaining mechanistic insights into the neural mechanisms underlying sleep disturbances in children with ASD will help us to develop better therapeutic interventions.

Complementary and Integrative Approaches to Sleep Disorders in Children

Sleep problems are very common in children and adolescents. Chronic insomnia is the leading cause of sleep disorders in children and adolescents. Adjunctive interventions that address low ferritin levels and vitamin D3 deficiency are helpful in children and adolescents. The addition of l-5-hydroxytryptophan, gabadone, l-theanine, Ashwagandha, omega 3 fatty acids, probiotics in bipolar disorder, and children with colic, meditation, and changing from a high-fat diet to a Mediterranean diet are also helpful adjunctive interventions. Actigraphy data should be collected in future sleep studies because subjective data may not indicate the true effect of the intervention.

Autism Spectrum Disorder and Complementary-Integrative Medicine

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects 0.6%-1.7% of children. The etiology of autism is hypothesized to include both biological and environmental factors (Watts, 2008). In addition to the core symptoms of social-communication delay and restricted, repetitive interests, co-occurring irritability/aggression, hyperactivity, and insomnia negatively impact adaptive functioning and quality of life of patients and families. Despite years of effort, no pharmacologic agent has been found that targets the core symptoms of ASD. The only FDA-approved agents are risperidone and aripiprazole for agitation and irritability in ASD, not for core symptoms. Though they effectively reduce irritability/violence, they do so at the expense of problematic side effects: metabolic syndrome, elevated liver enzymes, and extrapyramidal side effects. Thus, it is not surprising that many families of children with ASD turn to nonallopathic treatment, including dietary interventions, vitamins, and immunomodulatory agents subsumed under complementary-integrative medicine (CIM). Per recent studies, 27% to 88% of families report using a CIM treatment. In an extensive population-based survey of CIM, families of children with more severe ASD, comorbid irritability, GI symptoms, food allergies, seizures, and higher parental education tend to use CIM at higher rates. The perceived safety of CIM treatments as "natural treatment" over allopathic medication increases parental comfort in using these agents. The most frequently used CIM treatments include multivitamins, an elimination diet, and Methyl B12 injections. Those perceived most effective are sensory integration, melatonin, and antifungals. Practitioners working with these families should improve their knowledge about CIM as parents currently perceive little interest in and poor knowledge of CIM by physicians. This article reviews the most popular complementary treatments preferred by families with children with autism. With many of them having limited or poor quality data, clinical recommendations about the efficacy and safety of each treatment are discussed using the SECS versus RUDE criteria.

Prevalence of pineal gland calcification: systematic review and meta-analysis

BACKGROUND

Pineal gland calcification is the formation of corpora arenacea predominantly composed of calcium and phosphorus. It plays an important role in regulating the light/dark circadian changes to synchronize their daily physiological activities like feeding, metabolism, reproduction, and sleep through the secretion of melatonin. Therefore, this study aimed to assess the pooled prevalence of pineal gland calcification.

METHODS

A systematic review was done using published research articles from different electronic databases. Cross-sectional studies were included for systematic review and only studies conducted on the human population were included for quantitative analysis. Published articles were selected by assessing the title and abstract for relevance to the review objectives. Finally, the full text was retrieved for further assessment.

RESULTS

The pooled prevalence of pineal gland calcification was 61.65% [95% CI: 52.81, 70.49], with a heterogeneity of I² = 97.7%, P ≤ 0.001. According to the qualitative analysis, an increase in age, male sex, and white ethnicity are the major socio-demographic characteristics that increase the prevalence of pineal gland calcification.

CONCLUSION

The pooled prevalence of pineal gland calcification was higher compared with reports from previous studies. Different studies reported pineal gland calcification was most prevalent in the adult population compared with the pediatric age groups. According to the qualitative analysis, an increase in age, male sex, and white ethnicity are the major socio-demographic characteristics that increase the prevalence of pineal gland calcification.

The role of microRNAs in the molecular link between circadian rhythm and autism spectrum disorder

Circadian rhythm regulates physiological cycles of awareness and sleepiness. Melatonin production is primarily regulated by circadian regulation of gene expression and is involved in sleep homeostasis. If the circadian rhythm is abnormal, sleep disorders, such as insomnia and several other diseases, can occur. The term 'autism spectrum disorder (ASD)' is used to characterize people who exhibit a certain set of repetitive behaviors, severely constrained interests, social deficits, and/or sensory behaviors that start very early in life. Because many patients with ASD suffer from sleep disorders, sleep disorders and melatonin dysregulation are attracting attention for their potential roles in ASD. ASD is caused by abnormalities during the neurodevelopmental processes owing to various genetic or environmental factors. Recently, the role of microRNAs (miRNAs) in circadian rhythm and ASD have gained attraction. We hypothesized that the relationship between circadian rhythm and ASD could be explained by miRNAs that can regulate or be regulated by either or both. In this study, we introduced a possible molecular link between circadian rhythm and ASD. We performed a thorough literature review to understand their complexity.

Emerging therapeutics agents and recent advances in drug repurposing for Alzheimer's disease

Alzheimer's disease (AD) is a multivariate and diversified disease and affects the most sensitive areas of the brain, the cerebral cortex, and the hippocampus. AD is a progressive age-related neurodegenerative disease most often associated with memory deficits and cognition that get more worsen over time. The central theory on the pathophysiological hallmark features of AD is characterized by the accumulation of amyloid β (Aβ) peptides, also associated with tau proteins (τ) dysfunctioning which leads to distorted microtubular structure, affects the cholinergic system, and mitochondrial biogenesis. This review emphasizes how simple it is to find novel treatments for AD and focuses on several recently developed medications through repurposing that can speed up traditional drug development.

Efficacy of Melatonin for Insomnia in Children with Autism Spectrum Disorder: A Meta-analysis

AIM

 This study aimed to evaluate the effectiveness of melatonin in treating insomnia in children with autism spectrum disorder (ASD).

METHODS

 Comprehensive searches were conducted in the PubMed, EMBASE, and Web of Science databases from their inception to April 20, 2022. Data were extracted and assessed for quality by two researchers. Statistical analysis was performed using the Stata 15.0 software.

RESULTS

 Four studies including 238 patients were included. The results showed that compared with the control group, melatonin could shorten the sleep-onset latency (standardized mean difference [SMD] = - 1.34, 95% CI: -2.19 to -0.48), reduce the number of awakenings (SMD = -2.35, 95% CI: -4.62 to -0.08), and prolong the total sleep time (SMD = 1.42, 95% CI: 0.5-2.33) in children with ASD.

CONCLUSION

 Melatonin has a certain effect on relieving sleep disturbances in children with ASD, which can shorten sleep latency, reduce the number of awakenings, and prolong total sleep time. Larger studies are required to verify this hypothesis.

Circadian rhythms as modulators of brain health during development and throughout aging

The circadian clock plays a prominent role in neurons during development and throughout aging. This review covers topics pertinent to the role of 24-h rhythms in neuronal development and function, and their tendency to decline with aging. Pharmacological or behavioral modification that augment the function of our internal clock may be central to decline of cognitive disease and to future chronotherapy for aging-related diseases of the central nervous system.

A literature review of sleep problems and neurodevelopment disorders

INTRODUCTION

Sleep is an incredibly complex process that goes beyond relaxing and body resting. Disturbance in sleep leads to several short-term and long-term consequences. Neurodevelopmental diseases such as "autism spectrum disorder" (ASDs), Attention-deficit hyperactivity disorder (ADHD), and intellectual disability commonly experience sleep disorders that affect their clinical presentation, daily function, and quality of life.

DISCUSSION

The incidence of sleep problems in ASD patients ranges from 32 to 71.5%, especially insomnia, while an estimated 25-50% of people with ADHD report having sleep issues in clinical settings. The incidence of sleep issues is widespread in persons with intellectual disabilities, reaching up to 86%. This article is a literature review covering the neurodevelopmental disorder interaction with sleep disorder and different management.

CONCLUSION

Disorders of sleep are key concerns in children with neurodevelopmental disorders. In this group of patients, sleep disorders are common and tend to be chronic. Recognizing and diagnosis of sleep disorders will enhance their function, response to treatment, and quality of life.

Structure-guided isoform identification for the human transcriptome

Recently developed methods to predict three-dimensional protein structure with high accuracy have opened new avenues for genome and proteome research. We explore a new hypothesis in genome annotation, namely whether computationally predicted structures can help to identify which of multiple possible gene isoforms represents a functional protein product. Guided by protein structure predictions, we evaluated over 230,000 isoforms of human protein-coding genes assembled from over 10,000 RNA sequencing experiments across many human tissues. From this set of assembled transcripts, we identified hundreds of isoforms with more confidently predicted structure and potentially superior function in comparison to canonical isoforms in the latest human gene database. We illustrate our new method with examples where structure provides a guide to function in combination with expression and evolutionary evidence. Additionally, we provide the complete set of structures as a resource to better understand the function of human genes and their isoforms. These results demonstrate the promise of protein structure prediction as a genome annotation tool, allowing us to refine even the most highly curated catalog of human proteins. More generally we demonstrate a practical, structure-guided approach that can be used to enhance the annotation of any genome.

Circ-ERC2 Is Involved in Melatonin Synthesis by Regulating the miR-125a-5p/MAT2A Axis

The circadian rhythm of melatonin secretion in the pineal gland is highly conserved in vertebrates. Melatonin levels are always elevated at night. Acetylserotonin O-methyltransferase (ASMT) is the last enzyme in the regulation of melatonin biosynthesis (N-acetyl-5-hydroxytryptamine-melatonin). S-adenosylmethionine (SAM) is an important methyl donor in mammals and can be used as a substrate for the synthesis of melatonin. Methionine adenosyltransferase (MAT) catalyzes the synthesis of SAM from methionine and ATP and has a circadian rhythm. CircRNA is an emerging type of endogenous noncoding RNA with a closed loop. Whether circRNAs in the pineal gland can participate in the regulation of melatonin synthesis by binding miRNAs to target mat2a as part of the circadian rhythm is still unclear. In this study, we predicted the targeting relationship of differentially expressed circRNAs, miRNAs and mRNAs based on the results of rat pineal RNA sequencing. Mat2a siRNA transfection confirmed that mat2a is involved in the synthesis of melatonin. Circ-ERC2 and miR-125a-5p were screened out by software prediction, dual-luciferase reporter experiments, cell transfection, etc. Finally, we constructed a rat superior cervical ganglionectomy model (SCGx), and the results showed that circ-ERC2 could participate in the synthesis of melatonin through the miR-125a-5p/MAT2A axis. The results of the study revealed that circ-ERC2 can act as a molecular sponge of miR-125a-5p to regulate the synthesis of melatonin in the pineal gland by targeting mat2a. This experiment provides a basis for research on the circadian rhythm of noncoding RNA on pineal melatonin secretion.

Clinical efficacy and safety of intravenous ferric carboxymaltose treatment for restless legs symptoms and low serum ferritin in children with autism spectrum disorder

BACKGROUND

Restless legs syndrome (RLS) may be underdiagnosed in children with autism spectrum disorder (ASD) due to difficulty expressing the symptoms in their own words. In addition, administration of oral iron may be particularly difficult in children with ASD.

METHODS

This was a retrospective, open-label case series of children with ASD, restless legs (RL) symptoms, and serum ferritin <30 μg/L, who either had failed or did not tolerate oral iron, and were subsequently treated with intravenous (IV) ferric carboxymaltose (FCM). Patients received a single dose of IV FCM, 15 mg/kg up to a maximum dose of 750 mg. Data collected pre- and eight weeks post-infusion included presenting symptoms, serum ferritin, iron profile, and Clinical Global Impression Scale (CGI-Severity pre- and CGI-Improvement post-infusion). Adverse effects were assessed.

RESULTS

Nineteen children, 4-11 years old (12 male, median age 6, interquartile range (IQR 4-11) were included. A definite RLS diagnosis was identified in 6 verbal children (31.6%). RL symptoms (designated probable RLS) in the 13 other children met all RLS diagnostic criteria except "improvement of symptoms with movement," which was not definitively determined. Baseline median values were: ferritin 10 μg/L (IQR 10-16), iron 66.5 μg/dL (IQR 57-96), TIBC 382 μg/dL (IQR 360-411) and transferrin saturation 19% (IQR 14-28). Median CGI-S was 4 (moderate symptoms) (IQR 3-4). At eight weeks after IV FCM, all measures were improved. Median ferritin was 68 μg/L (IQR 62.5-109, p < 0.00045). Median CGI-I was 1 (very much improved) (IQR 1-2). All children meeting definite RLS criteria improved. Three children in the probable RLS group did not improve. Children meeting the full RLS criteria had lower baseline ferritin levels than those with a probable diagnosis (9 μg/L, IQR 9-10 vs. 13 μg/L, IQR 10-16, Mann-Whitney test p < 0.045). Adverse effects included lightheadedness, gastrointestinal discomfort, fever, and headache among others.

CONCLUSIONS

The majority of children (84.2%) with ASD, restless legs symptoms, and serum ferritin <30 μg/L had clinical improvement and significantly better serum iron parameters after a single IV FCM infusion. Although larger, randomized trials are needed, IV FCM appears to be a promising treatment for this subset of children with ASD.

Transcription factor RORα enforces stability of the Th17 cell effector program by binding to a Rorc cis-regulatory element

T helper 17 (Th17) cells regulate mucosal barrier defenses but also promote multiple autoinflammatory diseases. Although many molecular determinants of Th17 cell differentiation have been elucidated, the transcriptional programs that sustain Th17 cells in vivo remain obscure. The transcription factor RORγt is critical for Th17 cell differentiation; however, it is not clear whether the closely related RORα, which is co-expressed in Th17 cells, has a distinct role. Here, we demonstrated that although dispensable for Th17 cell differentiation, RORα was necessary for optimal Th17 responses in peripheral tissues. The absence of RORα in T cells led to reductions in both RORγt expression and effector function among Th17 cells. Cooperative binding of RORα and RORγt to a previously unidentified Rorc cis-regulatory element was essential for Th17 lineage maintenance in vivo. These data point to a non-redundant role of RORα in Th17 lineage maintenance via reinforcement of the RORγt transcriptional program.

Melatonin Treatment for Pediatric Patients with Insomnia: Is There a Place for It?

Sleep is a vital physiological function that is impaired in ranges from 10% in the typically developing pediatric population to over 80% in populations of children with neurodevelopmental disorders and/or psychiatric comorbidities. Pediatric insomnia disorder is an increasing public health concern given its negative impact on synaptic plasticity involved in learning and memory consolidation but also on mood regulation, hormonal development and growth, and its significant impact on quality of life of the child, the adolescent and the family. While first-line treatment of pediatric insomnia should include parental education on sleep as well as sleep hygiene measures and behavioural treatment approaches, pharmacological interventions may be necessary if these strategies fail. Melatonin treatment has been increasingly used off-label in pediatric insomnia, given its benign safety profile. This article aims to identify the possible role of melatonin treatment for pediatric insomnia, considering its physiological role in sleep regulation and the differential effects of immediate release (IR) versus prolonged release (PR) melatonin. For the physician dealing with pediatric insomnia, it is particularly important to be able to distinguish treatment rationales implying different dosages and times of treatment intake. Finally, we discuss the benefit-risk ratio for melatonin treatment in different pediatric populations, ranging from the general pediatric population to children with different types of neurodevelopmental disorders, such as autism spectrum disorder or ADHD.

Is Melatonin the “Next Vitamin D”?: A Review of Emerging Science, Clinical Uses, Safety, and Dietary Supplements

Melatonin has become a popular dietary supplement, most known as a chronobiotic, and for establishing healthy sleep. Research over the last decade into cancer, Alzheimer’s disease, multiple sclerosis, fertility, PCOS, and many other conditions, combined with the COVID-19 pandemic, has led to greater awareness of melatonin because of its ability to act as a potent antioxidant, immune-active agent, and mitochondrial regulator. There are distinct similarities between melatonin and vitamin D in the depth and breadth of their impact on health. Both act as hormones, affect multiple systems through their immune-modulating, anti-inflammatory functions, are found in the skin, and are responsive to sunlight and darkness. In fact, there may be similarities between the widespread concern about vitamin D deficiency as a “sunlight deficiency” and reduced melatonin secretion as a result of “darkness deficiency” from overexposure to artificial blue light. The trend toward greater use of melatonin supplements has resulted in concern about its safety, especially higher doses, long-term use, and application in certain populations (e.g., children). This review aims to evaluate the recent data on melatonin’s mechanisms, its clinical uses beyond sleep, safety concerns, and a thorough summary of therapeutic considerations concerning dietary supplementation, including the different formats available (animal, synthetic, and phytomelatonin), dosing, timing, contraindications, and nutrient combinations.

A perspective on molecular signalling dysfunction, its clinical relevance and therapeutics in autism spectrum disorder

Intellectual disability (ID) and autism spectrum disorder (ASD) are neurodevelopmental disorders that have become a primary clinical and social concern, with a prevalence of 2-3% in the population. Neuronal function and behaviour undergo significant malleability during the critical period of development that is found to be impaired in ID/ASD. Human genome sequencing studies have revealed many genetic variations associated with ASD/ID that are further verified by many approaches, including many mouse and other models. These models have facilitated the identification of fundamental mechanisms underlying the pathogenesis of ASD/ID, and several studies have proposed converging molecular pathways in ASD/ID. However, linking the mechanisms of the pathogenic genes and their molecular characteristics that lead to ID/ASD has progressed slowly, hampering the development of potential therapeutic strategies. This review discusses the possibility of recognising the common molecular causes for most ASD/ID based on studies from the available models that may enable a better therapeutic strategy to treat ID/ASD. We also reviewed the potential biomarkers to detect ASD/ID at early stages that may aid in diagnosis and initiating medical treatment, the concerns with drug failure in clinical trials, and developing therapeutic strategies that can be applied beyond a particular mutation associated with ASD/ID.

The trilateral interactions between mammalian target of rapamycin (mTOR) signaling, the circadian clock, and psychiatric disorders: an emerging model

Circadian (~24 h) rhythms in physiology and behavior are evolutionarily conserved and found in almost all living organisms. The rhythms are endogenously driven by daily oscillatory activities of so-called "clock genes/proteins", which are widely distributed throughout the mammalian brain. Mammalian (mechanistic) target of rapamycin (mTOR) signaling is a fundamental intracellular signal transduction cascade that controls important neuronal processes including neurodevelopment, synaptic plasticity, metabolism, and aging. Dysregulation of the mTOR pathway is associated with psychiatric disorders including autism spectrum disorders (ASD) and mood disorders (MD), in which patients often exhibit disrupted daily physiological rhythms and abnormal circadian gene expression in the brain. Recent work has found that the activities of mTOR signaling are temporally controlled by the circadian clock and exhibit robust circadian oscillations in multiple systems. In the meantime, mTOR signaling regulates fundamental properties of the central and peripheral circadian clocks, including period length, entrainment, and synchronization. Whereas the underlying mechanisms remain to be fully elucidated, increasing clinical and preclinical evidence support significant crosstalk between mTOR signaling, the circadian clock, and psychiatric disorders. Here, we review recent progress in understanding the trilateral interactions and propose an "interaction triangle" model between mTOR signaling, the circadian clock, and psychiatric disorders (focusing on ASD and MD).

Yield of array-CGH analysis in Tunisian children with autism spectrum disorder

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with strong genetic underpinnings. Microarray-based comparative genomic hybridization (aCGH) technology has been proposed as a first-level test in the genetic diagnosis of ASD and of neurodevelopmental disorders in general.

METHODS

We performed aCGH on 98 Tunisian children (83 boys and 15 girls) diagnosed with ASD according to DSM-IV criteria.

RESULTS

"Pathogenic" or "likely pathogenic" copy number variants (CNVs) were detected in 11 (11.2%) patients, CNVs of "uncertain clinical significance" in 26 (26.5%), "likely benign" or "benign" CNVs were found in 37 (37.8%) and 24 (24.5%) patients, respectively. Gene set enrichment analysis involving genes spanning rare "pathogenic," "likely pathogenic," or "uncertain clinical significance" CNVs, as well as SFARI database "autism genes" in common CNVs, detected eight neuronal Gene Ontology classes among the top 10 most significant, including synapse, neuron differentiation, synaptic signaling, neurogenesis, and others. Similar results were obtained performing g: Profiler analysis. Neither transcriptional regulation nor immune pathways reached significance.

CONCLUSIONS

aCGH confirms its sizable diagnostic yield in a novel sample of autistic children from North Africa. Recruitment of additional families is under way, to verify whether genetic contributions to ASD in the Tunisian population, differently from other ethnic groups, may involve primarily neuronal genes, more than transcriptional regulation and immune-related pathways.

Signalling pathways in autism spectrum disorder: mechanisms and therapeutic implications

Autism spectrum disorder (ASD) is a prevalent and complex neurodevelopmental disorder which has strong genetic basis. Despite the rapidly rising incidence of autism, little is known about its aetiology, risk factors, and disease progression. There are currently neither validated biomarkers for diagnostic screening nor specific medication for autism. Over the last two decades, there have been remarkable advances in genetics, with hundreds of genes identified and validated as being associated with a high risk for autism. The convergence of neuroscience methods is becoming more widely recognized for its significance in elucidating the pathological mechanisms of autism. Efforts have been devoted to exploring the behavioural functions, key pathological mechanisms and potential treatments of autism. Here, as we highlight in this review, emerging evidence shows that signal transduction molecular events are involved in pathological processes such as transcription, translation, synaptic transmission, epigenetics and immunoinflammatory responses. This involvement has important implications for the discovery of precise molecular targets for autism. Moreover, we review recent insights into the mechanisms and clinical implications of signal transduction in autism from molecular, cellular, neural circuit, and neurobehavioural aspects. Finally, the challenges and future perspectives are discussed with regard to novel strategies predicated on the biological features of autism.

Association between cord blood metabolites in tryptophan pathway and childhood risk of autism spectrum disorder and attention-deficit hyperactivity disorder

Alterations in tryptophan and serotonin have been implicated in various mental disorders; but studies are limited on child neurodevelopmental disabilities such as autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD). This prospective cohort study examined the associations between levels of tryptophan and select metabolites (5-methoxytryptophol (5-MTX), 5-hydroxytryptophan (5-HTP), serotonin, N-acetyltrytophan) in cord plasma (collected at birth) and physician-diagnosed ASD, ADHD and other developmental disabilities (DD) in childhood. The study sample (n = 996) derived from the Boston Birth Cohort, which included 326 neurotypical children, 87 ASD, 269 ADHD, and 314 other DD children (mutually exclusive). These participants were enrolled at birth and followed-up prospectively (from October 1, 1998 to June 30, 2018) at the Boston Medical Center. Higher levels of cord 5-MTX was associated with a lower risk of ASD (aOR: 0.56, 95% CI: 0.41, 0.77) and ADHD (aOR: 0.79, 95% CI: 0.65, 0.96) per Z-score increase, after adjusting for potential confounders. Similarly, children with cord 5-MTX ≥ 25th percentile (vs. <25th percentile) had a reduction in ASD (aOR: 0.27, 95% CI: 0.14, 0.49) and ADHD risks (aOR: 0.45, 95% CI: 0.29, 0.70). In contrast, higher levels of cord tryptophan, 5-HTP and N-acetyltryptophan were associated with higher risk of ADHD, with aOR: 1.25, 95% CI: 1.03, 1.51; aOR: 1.32, 95% CI: 1.08, 1.61; and aOR: 1.27, 95% CI: 1.05, 1.53, respectively, but not with ASD and other DD. Cord serotonin was not associated with ASD, ADHD, and other DD. Most findings remained statistically significant in the sensitivity and subgroup analyses.

Gene Expression Profile Associated with Asmt Knockout-Induced Depression-Like Behaviors and Exercise Effects in Mouse Hypothalamus

Sleep disorder caused by abnormal circadian rhythm is one of the main symptoms and risk factors of depression. As a known hormone regulating circadian rhythms, melatonin (MT) is also namely N-acetyl-5-methoxytryptamine. N-acetylserotonin methyltransferase (Asmt) is the key rate-limiting enzyme of MT synthesis and has been reportedly associated with depression. Although 50–90% of patients with depression have sleep disorders, there are no effective treatment ways in the clinic. Exercise can regulate circadian rhythm and play an important role in depression treatment. In the present study, we showed that Asmt knockout induced depression-like behaviors, which were ameliorated by swimming exercise. Moreover, swimming exercise increased serum levels of MT and 5-hydroxytryptamine (5-HT) in Asmt knockout mice. In addition, the microarray data identified 10 differentially expressed genes (DEGs) in KO mice compared with WT mice and 29 DEGs in KO mice after swimming exercise. Among the DEGs, the direction and magnitude of change in epidermal growth factor receptor pathway substrate 8-like 1 (Eps8l1) and phospholipase C-β 2 (Plcb2) were confirmed by qRT-PCR partly. Subsequent bioinformatic analysis showed that these DEGs were enriched significantly in the p53 signaling pathway, long-term depression and estrogen signaling pathway. In the protein–protein interaction (PPI) networks, membrane palmitoylated protein 1 (Mpp1) and p53-induced death domain protein 1 (Pidd1) were hub genes to participate in the pathological mechanisms of depression and exercise intervention. These findings may provide new targets for the treatment of depression.

Melatonin Rhythm and Its Relation to Sleep and Circadian Parameters in Children and Adolescents With Autism Spectrum Disorder

Introduction

Sleep problems are prevalent among individuals with autism spectrum disorder (ASD), and a role has been attributed to melatonin in this multifactorial comorbidity.

Methods

A cross-sectional study was conducted on 41 autistic children and adolescents (9.9 ± 3.02) and 24 children and adolescents with a normal intellectual function (8.42 ± 2.43) were used as controls. Subjects were matched for sex, body mass index, and pubertal stage, and all were drug-naive. Circadian and sleep parameters were studied using an ambulatory circadian monitoring (ACM) device, and saliva samples were collected around the onset of sleep to determine dim light melatonin onset (DLMO).

Results

Prepubertal individuals with ASD presented later DLMO and an earlier decline in melatonin during adolescence. A relationship was found between melatonin and both sleep and circadian parameters. Participants and controls with later DLMOs were more likely to have delayed sleep onset times. In the ASD group, subjects with the later daytime midpoint of temperature had a later DLMO. Later melatonin peak time and DLMO time were related to lower general motor activity and lower stability of its rhythms.

Conclusion

The melatonin secretion pattern was different in individuals with ASD, and it showed a relationship with sleep and circadian parameters. Alterations in DLMO have not been previously reported in ASD with the exception of more variable DLMO timing; however, high variability in the study design and sample characteristics prevents direct comparison. The ACM device enabled the measurement of circadian rhythm, a scarcely described parameter in autistic children. When studied in combination with other measures such as melatonin, ACM can offer further knowledge on sleep problems in ASD.

Dog Therapy in Supporting the Rehabilitation Process of Children with Autism

Introduction: Autism is not a specific condition. It is, however, a comprehensive disorder of psychomotor and social development. A number of factors, both environmental (family-related) and genetic, are believed to be the cause of autism. The percentage of children affected by autism has been increasing over the past 20 years. It is assumed that statistically, approximately 20 children in every 10,000 will become affected by this condition. Autism is 4 times more common in boys than in girls. The disorder is characterised by impaired mental growth, and, consequently, social and motor development. Research objective: The aim of the article is to present the role of dog therapy in supporting the process of therapeutic rehabilitation among children with autism. In particular, the following aspects were taken into account: breeds of canines used in dog therapy, mechanisms of influence concerning dog therapy on the child's body, as well as the forms and results obtained. Material and methods: The work is a narrative review. It was written on the basis of the document analysis method with the use of quantitative and qualitative techniques, as well as database searches for Polish and foreign scientific literature on the subject, i.e. Web of Science, PubMed and Google Scholar. In the article, the research results are presented in relation to the efficiency of applying dog therapy in the treatment of autistic children between 2002 and 2017, with emphasis on foreign literature. Results: The most commonly used forms of dog therapy used are: Animal Assisted Activity (AAA), Animal Assisted Therapy (AAT) and Animal Assisted Education (AAE). Conclusions: The use of dogs in the process of therapeutic rehabilitation has positive influence both on the autistic child and his/her family environment. It helps cope better with many difficulties and motivates to take up more activities. Dog therapy affects all spheres of personal development, i.e. mental, motor and socio-emotional.

Haploinsufficiency of a Circadian Clock Gene Bmal1 (Arntl or Mop3) Causes Brain-Wide mTOR Hyperactivation and Autism-like Behavioral Phenotypes in Mice

Approximately 50-80% of children with autism spectrum disorders (ASDs) exhibit sleep problems, but the contribution of circadian clock dysfunction to the development of ASDs remains largely unknown. The essential clock gene Bmal1 (Arntl or Mop3) has been associated with human sociability, and its missense mutation is found in ASD. Our recent study found that Bmal1-null mice exhibit a variety of autism-like phenotypes. Here, we further investigated whether an incomplete loss of Bmal1 function could cause significant autism-like behavioral changes in mice. Our results demonstrated that heterozygous Bmal1 deletion (Bmal1+/-) reduced the Bmal1 protein levels by ~50-75%. Reduced Bmal1 expression led to decreased levels of clock proteins, including Per1, Per2, Cry 1, and Clock but increased mTOR activities in the brain. Accordingly, Bmal1+/- mice exhibited aberrant ultrasonic vocalizations during maternal separation, deficits in sociability and social novelty, excessive repetitive behaviors, impairments in motor coordination, as well as increased anxiety-like behavior. The novel object recognition memory remained intact. Together, these results demonstrate that haploinsufficiency of Bmal1 can cause autism-like behavioral changes in mice, akin to those identified in Bmal1-null mice. This study provides further experimental evidence supporting a potential role for disrupted clock gene expression in the development of ASD.

Biological correlates of altered circadian rhythms, autonomic functions and sleep problems in autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by a complex and multifaceted neurobehavioral syndrome. In the last decades, several studies highlighted an increased prevalence of sleep problems in ASD, which would be associated with autonomic system and circadian rhythm disruption. The present review aimed to summarize the available literature about sleep problems in ASD subjects and about the possible biological factors implicated in circadian rhythm and autonomic system deregulation in this population, as well as possible therapeutic approaches. Shared biological underpinnings between ASD symptoms and altered circadian rhythms/autonomic functions are also discussed. Studies on sleep showed how ASD subjects typically report more problems regarding insufficient sleep time, bedtime resistance and reduced sleep pressure. A link between sleep difficulties and irritability, deficits in social skills and behavioral problems was also highlighted. Among the mechanisms implicated, alteration in genes related to circadian rhythms, such as CLOCK genes, and in melatonin levels were reported. ASD subjects also showed altered hypothalamic pituitary adrenal (HPA) axis and autonomic functions, generally with a tendency towards hyperarousal and hyper sympathetic state. Intriguingly, some of these biological alterations in ASD individuals were not associated only with sleep problems but also with more autism-specific clusters of symptoms, such as communication impairment or repetitive behaviors Although among the available treatments melatonin showed promising results, pharmacological studies for sleep problems in ASD need to follow more standardized protocols to reach more repeatable and reliable results. Further research should investigate the issue of sleep problems in ASD in a broader perspective, taking into account shared pathophysiological mechanisms for core and associated symptoms of ASD.

Differential effects of COVID-related lockdown on sleep-wake rhythms in adults with autism spectrum disorder compared to the general population

COVID‐related lockdown led to a radical modification of daily activities and routines which are known to affect sleep. Compared to the general population, participants with autism may be particularly vulnerable to the repercussions of lockdown on sleep, given their intrinsic inflexible adherence to routines and the high overall prevalence of sleep disturbances in this population. The study is a French nation‐wide online survey assessing sleep–wake rhythms and behaviors known to affect sleep (daily screen time, daylight exposure, and physical activity), before and during COVID‐related lockdown. Respondents were 207 adults with autism (56% female) and 1652 adults of the general population (77% female), with a mean age 35.3 years (SD 11.3). Before lockdown, the adults with autism displayed on average later bedtime and waking hours, lower sleep quality, more evening screen time, less exposure to daylight, and less exercise (all p < 0.01). Lockdown affected all studied measures of sleep and related exposures in a similar way in both groups: poorer self‐rated sleep quality as well as a less regular and delayed sleep–wake rhythm, longer screen time in the evening and less exposure to daylight (all p < 0.001). Adults with autism displayed significantly higher levels of sleep and circadian rhythm disturbances and less favorable daily routines known to regulate sleep. While the effect of confinement on sleep and sleep related behaviors was similar in both groups, the results highlight that the pre‐existing shift in circadian rhythms and lifestyles in adults with ASD further deteriorated during lockdown.

Cellular and molecular mechanisms underlying autism spectrum disorders and associated comorbidities: A pathophysiological review

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders that develop in early life due to interaction between several genetic and environmental factors and lead to alterations in brain function and structure. During the last decades, several mechanisms have been placed to explain the pathogenesis of autism. Unfortunately, these are reported in several studies and reviews which make it difficult to follow by the reader. In addition, some recent molecular mechanisms related to ASD have been unrevealed. This paper revises and highlights the major common molecular mechanisms responsible for the clinical symptoms seen in people with ASD, including the roles of common genetic factors and disorders, neuroinflammation, GABAergic signaling, and alterations in Ca⁺² signaling. Besides, it covers the major molecular mechanisms and signaling pathways involved in initiating the epileptic seizure, including the alterations in the GABAergic and glutamate signaling, vitamin and mineral deficiency, disorders of metabolism, and autoimmunity. Finally, this review also discusses sleep disorder patterns and the molecular mechanisms underlying them.

Sleep Disturbances in Children Affected by Autism Spectrum Disorder

BACKGROUND

Sleep disturbances are common in children affected by Autism Spectrum Disorder (ASD). The aim of our study was to describe sleep characteristics and disturbances in children with ASD, to evaluate possible related factors, and to assess parental stress.

METHODS

Hundred children with a diagnosis of ASD (mean age: 66.7 months, SD: 27.4, range: 24.7-152.1 months, n = 79 males) were included in the study. We collected data on sociodemographic, clinical, genetic and instrumental variables as well as comorbid conditions. Parents filled out the Questionnaire on sleep behavior in the first years of life, the BEARS questionnaire, and the Parenting Stress Index Short Form. From the analysis on sleep characteristics, we excluded 25 children treated with melatonin.

RESULTS

Fifty-seven (57%) out of 100 children met the criteria for insomnia. Sleep disorders were associated with developmental or cognitive delay, emotional and behavioral problems (such as anxiety problems and aggressive behaviors) and absence of strategies for inducing sleep after nocturnal awakenings. From parents' reports, sleep disorders had diurnal repercussions on their offspring; however, we found no statistical correlation between disturbances and family stress. Also, no significant correlation was found between sleep disturbances and epilepsy. Finally, a statistical correlation was found between the regular intake of melatonin and the resolution of insomnia.

CONCLUSIONS

Multifactorial variables may be associated to insomnia that could have an impact on the children' behavior. Clinicians need to be aware of the value of screening for sleep disturbance in children with ASD to integrate sleep interventions in the treatment plan.

Downregulation of AANAT by c-Fos in tubular epithelial cells with membranous nephropathy

Melatonin is a hormone majorly secreted by the pineal gland and contributes to a various type of physiological functions in mammals. The melatonin production is tightly limited to the AANAT level, yet the most known molecular mechanisms underlying AANAT gene transcription is limited in the pinealocyte. Here, we find that c-Fos and cAMP-response element-binding protein (CREB) decreases and increases the AANAT transcriptional activity in renal tubular epithelial cell, respectively. Notably, c-Fos knockdown significantly upregulates melatonin levels in renal tubular cells. Functional results indicate that AANAT expression is decreased by c-Fos and resulted in enhancement of cell damage in albumin-injury cell model. We further find an inverse correlation between c-Fos and AANAT levels in renal tubular cells from experimental membranous nephropathy (MN) samples and clinical MN specimens. Our finding provides the molecular basis of c-Fos in transcriptionally downregulating expression of AANAT and melatonin, and elucidate the protective role of AANAT in preventing renal tubular cells death in albumin-injury cell model and MN progression.

Control of Tissue Fibrosis by 5-Methoxytryptophan, an Innate Anti-Inflammatory Metabolite

Tissue fibrosis causes debilitating human diseases such as liver cirrhosis, heart failure, chronic kidney disease and pulmonary insufficiency. It is a dynamic process orchestrated by specific subsets of monocyte-macrophages, fibroblasts, pericytes and hepatic stellate cells. Fibrosis is linked to tissue inflammation. Pro-inflammatory macrophages promote fibrosis by driving myofibroblast differentiation and macrophage myofibroblast transition. Myofibroblasts express α-smooth muscle cell actin (α-SMA) and secrete extracellular matrix (ECM) proteins notably collagen I and III. Deposition of ECM proteins at injury sites and interstitial tissues distorts normal structure and impairs vital functions. Despite advances in the mechanisms of fibrosis at cellular, molecular and genetic levels, prevention and treatment of fibrotic diseases remain poorly developed. Recent reports suggest that 5-methoxytryptophan (5-MTP) is effective in attenuating injury-induced liver, kidney, cardiac and pulmonary fibrosis. It inhibits macrophage activation and blocks fibroblast differentiation to myofibroblasts. Furthermore, it inhibits hepatic stellate cell differentiation into myofibroblasts. As 5-MTP is an endogenous molecule derived from tryptophan catabolism via tryptophan hydroxylase pathway, it is well-suited as a lead compound for developing new anti-fibrotic drugs. This article provides an overview of 5-MTP synthesis, and a critical review of its anti-fibrotic activities. Its mechanisms of actions and potential therapeutic value will be discussed.

The Reserve/Maximum Capacity of Melatonin's Synthetic Function for the Potential Dimorphism of Melatonin Production and Its Biological Significance in Mammals

In this article, we attempt to classify a potential dimorphism of melatonin production. Thus, a new concept of "reserve or maximum capacity of melatonin synthetic function" is introduced to explain the subtle dimorphism of melatonin production in mammals. Considering ASMT/ASMTL genes in the pseudoautosomal region of sex chromosomes with high prevalence of mutation in males, as well as the sex bias of the mitochondria in which melatonin is synthesized, we hypothesize the existence of a dimorphism in melatonin production to favor females, which are assumed to possess a higher reserve capacity for melatonin synthesis than males. Under physiological conditions, this subtle dimorphism is masked by the fact that cells or tissues only need baseline melatonin production, which can be accomplished without exploiting the full potential of melatonin's synthetic capacity. This capacity is believed to exceed the already remarkable nocturnal increase as observed within the circadian cycle. However, during aging or under stressful conditions, the reserve capacity of melatonin's synthetic function is required to be activated to produce sufficiently high levels of melatonin for protective purposes. Females seem to possess a higher reserve/maximum capacity for producing more melatonin than males. Thus, this dimorphism of melatonin production becomes manifest and detectable under these conditions. The biological significance of the reserve/maximum capacity of melatonin's synthetic function is to improve the recovery rate of organisms from injury, to increase resistance to pathogen infection, and even to enhance their chances of survival by maximizing melatonin production under stressful conditions. The higher reserve/maximum capacity of melatonin synthesis in females may also contribute to the dimorphism in longevity, favoring females in mammals.