Association of serum allopregnanolone with restricted and repetitive behaviors in adult males with autism

Androgen levels in autism spectrum disorders: a systematic review and meta-analysis

Background

Accumulating evidence suggests that the autism spectrum disorder (ASD) population exhibits altered hormone levels, including androgens. However, studies on the regulation of androgens, such as testosterone and dehydroepiandrosterone (DHEA), in relation to sex differences in individuals with ASD are limited and inconsistent. We conducted the systematic review with meta-analysis to quantitatively summarise the blood, urine, or saliva androgen data between individuals with ASD and controls.

Methods

A systematic search was conducted for eligible studies published before 16 January 2023 in six international and two Chinese databases. We computed summary statistics with a random-effects model. Publication bias was assessed using funnel plots and heterogeneity using I2 statistics. Subgroup analysis was performed by age, sex, sample source, and measurement method to explain the heterogeneity.

Results

17 case-control studies (individuals with ASD, 825; controls, 669) were assessed. Androgen levels were significantly higher in individuals with ASD than that in controls (SMD: 0.27, 95% CI: 0.06-0.48, P=0.01). Subgroup analysis showed significantly elevated levels of urinary total testosterone, urinary DHEA, and free testosterone in individuals with ASD. DHEA level was also significantly elevated in males with ASD.

Conclusion

Androgen levels, especially free testosterone, may be elevated in individuals with ASD and DHEA levels may be specifically elevated in males.

Neuroactive Steroids, Toll-like Receptors, and Neuroimmune Regulation: Insights into Their Impact on Neuropsychiatric Disorders

Pregnane neuroactive steroids, notably allopregnanolone and pregnenolone, exhibit efficacy in mitigating inflammatory signals triggered by toll-like receptor (TLR) activation, thus attenuating the production of inflammatory factors. Clinical studies highlight their therapeutic potential, particularly in conditions like postpartum depression (PPD), where the FDA-approved compound brexanolone, an intravenous formulation of allopregnanolone, effectively suppresses TLR-mediated inflammatory pathways, predicting symptom improvement. Additionally, pregnane neurosteroids exhibit trophic and anti-inflammatory properties, stimulating the production of vital trophic proteins and anti-inflammatory factors. Androstane neuroactive steroids, including estrogens and androgens, along with dehydroepiandrosterone (DHEA), display diverse effects on TLR expression and activation. Notably, androstenediol (ADIOL), an androstane neurosteroid, emerges as a potent anti-inflammatory agent, promising for therapeutic interventions. The dysregulation of immune responses via TLR signaling alongside reduced levels of endogenous neurosteroids significantly contributes to symptom severity across various neuropsychiatric disorders. Neuroactive steroids, such as allopregnanolone, demonstrate efficacy in alleviating symptoms of various neuropsychiatric disorders and modulating neuroimmune responses, offering potential intervention avenues. This review emphasizes the significant therapeutic potential of neuroactive steroids in modulating TLR signaling pathways, particularly in addressing inflammatory processes associated with neuropsychiatric disorders. It advances our understanding of the complex interplay between neuroactive steroids and immune responses, paving the way for personalized treatment strategies tailored to individual needs and providing insights for future research aimed at unraveling the intricacies of neuropsychiatric disorders.

Prenatal Sex Hormone Exposure Is Associated with the Development of Autism Spectrum Disorder

Sexual differentiation is a major developmental process. Sex differences resulting from sexual differentiation have attracted the attention of researchers. Unraveling what contributes to and underlies sex differences will provide valuable insights into the development of neurodevelopmental disorders that exhibit sex biases. Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects an individual's social interaction and communication abilities, and its male preponderance has been consistently reported in clinical studies. The etiology of male preponderance remains unclear, but progress has been made in studying prenatal sex hormone exposure. The present review examined studies that focused on the association between prenatal testosterone exposure and ASD development, as well as sex-specific behaviors in individuals with ASD. This review also included studies on maternal immune activation-induced developmental abnormalities that also showed striking sex differences in offspring and discussed its possible interacting roles in ASD so as to present a potential approach for future studies on sex biases in ASD.

Allopregnanolone: An overview on its synthesis and effects

Allopregnanolone, a 3α,5α-progesterone metabolite, acts as a potent allosteric modulator of the γ-aminobutyric acid type A receptor. In the present review, the synthesis of this neuroactive steroid occurring in the nervous system is discussed with respect to physiological and pathological conditions. In addition, its physiological and neuroprotective effects are also reported. Interestingly, the levels of this neuroactive steroid, as well as its effects, are sex-dimorphic, suggesting a possible gender medicine based on this neuroactive steroid for neurological disorders. However, allopregnanolone presents low bioavailability and extensive hepatic metabolism, limiting its use as a drug. Therefore, synthetic analogues or a different therapeutic strategy able to increase allopregnanolone levels have been proposed to overcome any pharmacokinetic issues.

The Relationship of Steroid Hormones, Genes Related to Testosterone Metabolism and Behavior in Boys With Autism in Slovakia

OBJECTIVE

Purpose of the study was to identify the relationship among actual plasmatic levels of steroid hormones and behavioral manifestations in boys with autism and to assess the genetic contribution to these manifestations.

METHODS

172 boys with autism under 10 years of age and 135 neurotypical boys attended the study. ADI-R and ADOS-2 were used to evaluate the core symptom severities. Problem behavior was assessed using BPI-01 questionnaire. Levels of testosterone, estradiol, dehydroepiandrosterone, dehydroepiandrosterone-sulfate and sex hormone binding globulin (SHBG) were measured in plasma of autistic boys. Three SNPs (in ESR1, SHBG, SRD5A2 genes) and one STR in AR gene (number of CAG repeats in first exon) were assessed. Hormonal levels and number of CAG repeats in AR gene were used for correlation analysis with behavioral measures. Genotype and allelic frequencies were compared among autistic and neurotypical boys.

RESULTS

We found negative relationship among SHBG levels and restricted, repetitive behaviors (measured by ADOS-2) and positive relationship among actual testosterone levels and frequency of stereotyped behavior (measured by BPI-01).

CONCLUSION

Actual levels of SHBG and testosterone are related to severities of restricted and repetitive behaviors in boys with autism. Mechanisms of action of these hormones in brain require further investigation.

Alteration of peripheral cortisol and autism spectrum disorder: A meta-analysis

Cortisol is the main HPA axis hormone secreted by the adrenal cortex, and influences metabolism, cognition, and behavior. Recently, a plethora of studies have tried to confirm the correlation between peripheral cortisol and autism spectrum disorder (ASD). However, the results were controversial. We assessed the effects of peripheral cortisol on ASD in this study. The included studies were identified according to the inclusion and exclusion criteria. The pooled Hedges' g and its 95% confidence interval were selected to evaluate the association between peripheral cortisol and ASD. Subgroup analyses, sensitivity analyses, meta-regression, and publication bias tests were also undertaken based on the obtained information. There were a total of twelve studies with 375 ASD patients and 335 controls included in our meta-analysis. Obvious heterogeneity across studies was found in the overall analysis. Peripheral cortisol levels were significantly elevated in ASD patients compared with controls in the absence of obvious heterogeneity. A single study did not influence the overall comparison results. Meta-regression analyses revealed that age and gender of the included subjects, sample size, and publication year did not moderate effects on the present results. These findings may provide us some targeted strategies to the diagnosis and treatment of ASD.

Biopsychological correlates of repetitive and restricted behaviors in autism spectrum disorders

BACKGROUND

Autism Spectrum Disorder (ASD) is considered a neurodevelopmental condition that is characterized by alterations in social interaction and communication, as well as patterns of restrictive and repetitive behaviors (RRBs). RRBs are defined as broad behaviors that comprise stereotypies, insistence on sameness, and attachment to objects or routines. RRBs can be divided into lower-level behaviors (motor, sensory, and object-manipulation behaviors) and higher-level behaviors (restrictive interests, insistence on sameness, and repetitive language). According to the DSM-5, the grade of severity in ASD partially depends on the frequency of RRBs and their consequences for disrupting the life of patients, affecting their adaptive skills, and increasing the need for parental support.

METHODS

We conducted a systematic review to examine the biopsychological correlates of the symptomatic domains of RRBs according to the type of RRBs (lower- or higher-level). We searched for articles from the National Library of Medicine (PubMed) using the terms: autism spectrum disorders, ASD, and autism-related to executive functions, inhibitory control, inflexibility, cognitive flexibility, hyper or hypo connectivity, and behavioral approaches. For describing the pathophysiological mechanism of ASD, we also included animal models and followed PRISMA guidelines.

RESULTS

One hundred and thirty-one articles were analyzed to explain the etiology, continuance, and clinical evolution of these behaviors observed in ASD patients throughout life.

CONCLUSIONS

Biopsychological correlates involved in the origin of RRBs include alterations in a) neurotransmission system, b) brain volume, c) inadequate levels of growth factors, d) hypo- or hyper-neural connectivity, e) impairments in behavioral inhibition, cognitive flexibility, and monitoring and f) non-stimulating environments. Understanding these lower- and higher-level of RRBs can help professionals to improve or design novel therapeutic strategies.

Molecular Mechanisms of Aberrant Neuroplasticity in Autism Spectrum Disorders (Review)

This review presents the analysis and systematization of modern data on the molecular mechanisms of autism spectrum disorders (ASD) development. Polyetiology and the multifactorial nature of ASD have been proved. The attempt has been made to jointly review and systematize current hypotheses of ASD pathogenesis at the molecular level from the standpoint of aberrant brain plasticity. The mechanism of glutamate excitotoxicity formation, the effect of imbalance of neuroactive amino acids and their derivatives, neurotransmitters, and hormones on the ASD formation have been considered in detail. The strengths and weaknesses of the proposed hypotheses have been analyzed from the standpoint of evidence-based medicine. The conclusion has been drawn on the leading role of glutamate excitotoxicity as a biochemical mechanism of aberrant neuroplasticity accompanied by oxidative stress and mitochondrial dysfunction. The mechanism of aberrant neuroplasticity has also been traced at the critical moments of the nervous system development taking into account the influence of various factors of the internal and external environment. New approaches to searching for ASD molecular markers have been considered.

Ilex kudingcha C.J. Tseng Mitigates Phenotypic Characteristics of Human Autism Spectrum Disorders in a Drosophila Melanogaster Rugose Mutant

Autism spectrum disorders (ASD) have heterogeneous etiologies involving dysfunction of central nervous systems, for which no effective pan-specific treatments are available. Ilex kudingcha (IK) C.J. Tseng is a nootropic botanical used in Asia for neuroprotection and improvement of cognition. This study establishes that a chemically characterized extract from IK (IKE) mitigates behavioral traits in the Drosophila melanogaster rugose mutant, whose traits resemble human ASD, and examines possible mechanisms. IKE treatment significantly ameliorated deficits in social interaction, short-term memory, and locomotor activity in Drosophila rugose, and significantly increased synaptic bouton number of size more than 2 μm² in the neuromuscular junctions (NMJs) of Drosophila rugose. To clarify mechanism(s) of IKE action, methylphenidate (MPH), a dopamine transporter inhibitor, was included as a reference drug in the behavioral assays: MPH significantly improved social interaction and short-term memory deficit in Drosophila rugose; administration of the dopamine D1 receptor antagonist SCH23390 and dopamine D2 receptor antagonist sulpiride reversed the ameliorative effects of both MPH and IKE on the social interaction deficits of Drosophila rugose. To extend analysis of IKE treatment to the vertebrate central nervous system, ASD-associated gene expression in mouse hippocampus was studied by RNA-seq: IKE treatment altered the expression of genes coding phosphoinositide 3-kinases/protein kinase B (PI3K-Akt), proteins in glutamatergic, dopaminergic, serotonergic, and GABAergic synapses, cAMP response element-binding protein (CREB), and RNA transporter proteins. These results provide a foundation for further analysis of IKE as a candidate for treatment of some forms of ASD.