Speech-Stimulating Substances in Autism Spectrum Disorders

TINY IN SIZE, BIG IN IMPACT: EXTRACELLULAR VESICLES AS MODULATORS OF MOOD, ANXIETY AND NEURODEVELOPMENTAL DISORDERS

Extracellular Vesicles (EVs) are tiny vesicles used by cells as means of cellular communication, through which the function and state of a given cell can be changed. A body of evidence has suggested that EVs could be culprits in the development and progression of various types of diseases, including neurodegenerative diseases such as Multiple Sclerosis (MS) and Alzheimer's Disease (AD). Unsurprisingly, EVs have also been implicate in mood, anxiety and neurodevelopmental disorders, such as Major Depressive Disorder (MDD), anxiety disorder and Autism-Spectrum Disorder (ASD), respectively. Here, we review the state-of-art regarding the roles of EVs in the aforementioned diseases and focus on the mechanisms by which they can cause and worsen disease. Harnessing the knowledge of EVs is not only important to deliver different cargos to cells in a specific manner to treat these diseases, but also to establish reliable disease biomarkers, which will aid in the early disease diagnosis and treatment, increasing the chance of successful treatment.

Symptomatic, Genetic, and Mechanistic Overlaps between Autism and Alzheimer's Disease

Autism spectrum disorder (ASD) and Alzheimer's disease (AD) are neurodevelopmental and neurodegenerative disorders affecting two opposite ends of life span, i.e., childhood and old age. Both disorders pose a cumulative threat to human health, with the rate of incidences increasing considerably worldwide. In the context of recent developments, we aimed to review correlated symptoms and genetics, and overlapping aspects in the mechanisms of the pathogenesis of ASD and AD. Dementia, insomnia, and weak neuromuscular interaction, as well as communicative and cognitive impairments, are shared symptoms. A number of genes and proteins linked with both disorders have been tabulated, including MECP2, ADNP, SCN2A, NLGN, SHANK, PTEN, RELN, and FMR1. Theories about the role of neuron development, processing, connectivity, and levels of neurotransmitters in both disorders have been discussed. Based on the recent literature, the roles of FMRP (Fragile X mental retardation protein), hnRNPC (heterogeneous ribonucleoprotein-C), IRP (Iron regulatory proteins), miRNAs (MicroRNAs), and α-, β0, and γ-secretases in the posttranscriptional regulation of cellular synthesis and processing of APP (amyloid-β precursor protein) have been elaborated to describe the parallel and overlapping routes and mechanisms of ASD and AD pathogenesis. However, the interactive role of genetic and environmental factors, oxidative and metal ion stress, mutations in the associated genes, and alterations in the related cellular pathways in the development of ASD and AD needs further investigation.

Autism - A Comprehensive Array of Prominent Signs and Symptoms

BACKGROUND

Autism Spectrum Disorder (ASD) is a multifaceted neurodevelopmental condition characterized by multiple psychological and physiological impairments in young children. According to the recent reports, 1 out of every 58 newly-born children is suffering from autism. The aetiology of the disorder is complex and poorly understood, hindering the adaptation of targeted and effective therapies. There are no well- established diagnostic biomarkers for autism. Hence the analysis of symptoms by the pediatricians plays a critical role in the early intervention.

METHODS

In the present report, we have emphasized 24 behavioral, psychological and clinical symptoms of autism.

RESULTS

Impaired social interaction, restrictive and narrow interests, anxiety, depression; aggressive, repetitive, rigid and self-injurious behavior, lack of consistency, short attention span, fear, shyness and phobias, hypersensitivity and rapid mood alterations, high level of food and toy selectivity; inability to establish friendships or follow the instructions; fascination by round spinning objects and eating non-food materials are common psychological characteristics of autism. Speech or hearing impairments, poor cognitive function, gastrointestinal problems, weak immunity, disturbed sleep and circadian rhythms, weak motor neuromuscular interaction, lower level of serotonin and neurotransmitters, headache and body pain are common physiological symptoms.

CONCLUSION

A variable qualitative and quantitative impact of this wide range of symptoms is perceived in each autistic individual, making him/her distinct, incomparable and exceptional. Selection and application of highly personalized medical and psychological therapies are therefore recommended for the management and treatment of autism.

The urinary biopterin in autism spectrum disorder

Objective

The aim of the study was to determine whether biopterin is present in significantly lower quantities in urine samples of patients with autism spectrum disorder (ASD) compared to healthy individuals.

Methods

The concentration of biopterin in urine samples was measured by ELISA using commercially available kit. The study involved 53 children aged 3–16 years with ASD and 60 healthy children aged 2–14 years.

Results

Significantly lower biopterin concentration was observed in autistic patients compared to the control group. However, no significant difference was observed between mild, moderate, and severe ASD.

Conclusion

One of the potential causes of decrease in urinary biopterin levels may be tetrahydrobiopterin (BH4) deficiency, which has extensive and serious health consequences for the nervous system. The results of measuring biopterin as a fully oxidized form of BH4 may suggest that biosynthesis or regeneration of BH4 may be decreased in children with ASD. On the other hand, decreased urinary biopterin levels in children with ASD may be due to BH4 overuse, a good regeneration process, and decreased urinary excretion; and abnormalities in BH4 metabolism appear to be related to the aetiology of ASD or may be due to ASD.

Neurotransmitter, Antioxidant and Anti-neuroinflammatory Mechanistic Potentials of Herbal Medicines in Ameliorating Autism Spectrum Disorder

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental issue that disrupts behavior, nonverbal communication, and social interaction, impacting all aspects of an individual's social development. The underlying origin of autism is unclear, however, oxidative stress, as well as serotonergic, adrenergic and dopaminergic systems are thought to be implicated in ASD. Despite the fact that there is no effective medication for autism, current pharmacological treatments are utilized to ameliorate some of the symptoms such as selfmutilation, aggression, repetitive and stereotyped behaviors, inattention, hyperactivity, and sleep disorders.

METHODS

In accord with the literature regarding the activity of herbal medicines on neurotransmitter function, we aimed to review the most worthy medicinal herbs possessing neuroprotective effects.

RESULTS

Based on the outcome, medicinal herbs such as Zingiber officinale, Astragalus membranaceu, Ginkgo biloba, Centella asiatica and Acorus calamus, have antioxidant activity, which can influence neurotransmitter systems and are potentially neuroprotective.

CONCLUSION

Consequently, these herbs, in theory at least, appear to be suitable candidates within an overall management strategy for those on the autism spectrum.

Stem Cell-Derived Exosomes in Autism Spectrum Disorder

Neurodevelopmental lifelong pathologies defined by problems with social interaction, communication capacity and presence of repetitive/stereotyped clusters of behavior and interests are grouped under the definition of autism spectrum disorder (ASD). ASD prevalence is still increasing, indicating the need to identify specific biomarkers and novel pharmacotherapies. Neuroinflammation and neuro-immune cross-talk dysregulation are specific hallmarks of ASD, offering the possibility of treating these disorders by stem cell therapy. Indeed, cellular strategies have been postulated, proposed and applied to ASD. However, less is known about the molecular action mechanisms of stem cells. As a possibility, the positive and restorative effects mediated by stem cells could be due to their paracrine activity, by which stem cells produce and release several ameliorative and anti-inflammatory molecules. Among the secreted complex tools, exosomes are sub-organelles, enriched by RNA and proteins, that provide cell-to-cell communication. Exosomes could be the mediators of many stem cell-associated therapeutic activities. This review article describes the potential role of exosomes in alleviating ASD symptoms.