The importance of autism research

The multifaceted role of mitochondria in autism spectrum disorder

Normal brain functioning relies on high aerobic energy production provided by mitochondria. Failure to supply a sufficient amount of energy, seen in different brain disorders, including autism spectrum disorder (ASD), may have a significant negative impact on brain development and support of different brain functions. Mitochondrial dysfunction, manifested in the abnormal activities of the electron transport chain and impaired energy metabolism, greatly contributes to ASD. The aberrant functioning of this organelle is of such high importance that ASD has been proposed as a mitochondrial disease. It should be noted that aerobic energy production is not the only function of the mitochondria. In particular, these organelles are involved in the regulation of Ca2+ homeostasis, different mechanisms of programmed cell death, autophagy, and reactive oxygen and nitrogen species (ROS and RNS) production. Several syndromes originated from mitochondria-related mutations display ASD phenotype. Abnormalities in Ca2+ handling and ATP production in the brain mitochondria affect synaptic transmission, plasticity, and synaptic development, contributing to ASD. ROS and Ca2+ regulate the activity of the mitochondrial permeability transition pore (mPTP). The prolonged opening of this pore affects the redox state of the mitochondria, impairs oxidative phosphorylation, and activates apoptosis, ultimately leading to cell death. A dysregulation between the enhanced mitochondria-related processes of apoptosis and the inhibited autophagy leads to the accumulation of toxic products in the brains of individuals with ASD. Although many mitochondria-related mechanisms still have to be investigated, and whether they are the cause or consequence of this disorder is still unknown, the accumulating data show that the breakdown of any of the mitochondrial functions may contribute to abnormal brain development leading to ASD. In this review, we discuss the multifaceted role of mitochondria in ASD from the various aspects of neuroscience.

Mutations associated with autism lead to similar synaptic and behavioral alterations in both sexes of male and female mouse brain

Autism spectrum disorder (ASD) is a neurodevelopmental disorder based on synaptic abnormalities. The estimated prevalence rate of male individuals diagnosed with ASD prevails over females is in a proportion of 4:1. Consequently, males remain the main focus in ASD studies in clinical and experimental settings. Meanwhile, some studies point to an underestimation of this disorder in females. In this work, we studied the sex differences of the synaptic and behavioral phenotypes of ASD mouse models. Juvenile male and female Shank3Δ4-22 and Cntnap2-/- mutant mice and their WT littermates were used in the experiments. The animals were subjected to a Three-Chamber Sociability Test, then euthanized, and the whole cortex was used for the evaluation of the synaptic phenotype. Protein levels of glutamatergic (NR1) and GABAergic (GAD1 and VGAT) neuronal markers were measured. Protein level of synaptophysin (Syp) was also measured. Dendritic spine density in somatosensory neurons was analyzed by Golgi staining methods. Spine Density and GAD1, NR1, VGAT, and Syp levels were significantly reduced in Shank3Δ4-22 and Cntnap2-/- mice compared to the control group irrespective of sex, indicating impaired synaptic development in the mutant mice. These results were consistent with the lack of differences in the three-chamber sociability test between male and female mice. In conclusion, female ASD mice of both mutations undergo similar synaptic aberrations as their male counterparts and need to be studied along with the male animals. Finally, this work urges the psychiatry scientific community to use both sexes in their investigations.

Parsing the heterogeneity of brain-symptom associations in autism spectrum disorder via random forest with homogeneous canonical correlation

BACKGROUND

Autism spectrum disorder (ASD) is a highly heterogeneous developmental disorder, but the neuroimaging substrates of its heterogeneity remain unknown. The difficulty lies mainly on the significant individual variability in the brain-symptom association.

METHODS

T1-weighted magnetic resonance imaging data from the Autism Brain Imaging Database Exchange (ABIDE) (N_TDC = 1146) were used to generate a normative model to map brain structure deviations of cases (N_ASD = 571). Voxel-based morphometry (VBM) was used to compute gray matter volume (GMV). Singular Value Decomposition (SVD) was employed to perform dimensionality reduction. A tree-based algorithm was proposed to identify the ASD subtypes according to the pattern of brain-symptom association as assessed by a homogeneous canonical correlation.

RESULTS

We identified 4 ASD subtypes with distinct association patterns between residual volumes and a social symptom score. More severe the social symptom was associated with greater GMVs in both the frontoparietal regions for the subtype1 (r = 0.29-0.44) and the ventral visual pathway for the subtype3 (r = 0.19-0.23), but lower GMVs in both the right anterior cingulate cortex for the subtype4 (r = -0.25) and a few subcortical regions for the subtype2 (r = -0.31-0.20). The subtyping significantly improved the classification accuracy between cases and controls from 0.64 to 0.75 (p < 0.05, permutation test), which was also better than the accuracy of 0.68 achieved by the k-means-based subtyping (p < 0.01).

LIMITATIONS

Sample size limited the study due to the missing data.

CONCLUSIONS

These findings suggest that the heterogeneity of ASD might reflect changes in different subsystems of the social brain, especially including social attention, motivation, perceiving and evaluation.

Heart Rate Variability Biofeedback to Treat Anxiety in Young People With Autism Spectrum Disorder: Findings From a Home-Based Pilot Study

Background

People with autism spectrum disorder (ASD) frequently experience high levels of anxiety. Despite this, many clinical settings do not provide specialist ASD mental health services, and demand for professional support frequently outstrips supply. Across many sectors of health, investigators have explored digital health solutions to mitigate demand and extend the reach of professional practice beyond traditional clinical settings.

Objective

This critical appraisal and pilot feasibility study examines heart rate variability (HRV) biofeedback as an approach to help young people with ASD to manage anxiety symptoms outside of formal settings. The aim is to explore the use of portable biofeedback devices to manage anxiety, while also highlighting the risks and benefits of this approach with this population.

Methods

We assessed the feasibility of using home-based HRV biofeedback for self-management of anxiety in young people with ASD. We adopted coproduction, involving people with ASD, to facilitate development of the study design. Next, a separate pilot with 20 participants with ASD (n=16, 80% male participants and n=4, 20% female participants, aged 13-24 years; IQ>70) assessed adoption and acceptability of HRV biofeedback devices for home use over a 12-week period. Data were collected from both carers and participants through questionnaires and interviews; participants also provided single-lead electrocardiogram recordings as well as daily reports through smartphone on adoption and use of their device.

Results

Pre-post participant questionnaires indicated a significant reduction in anxiety in children (t₆=2.55; P=.04; Cohen d=0.99) as well as adults (t₇=3.95; P=.006; Cohen d=0.54). Participant age was significantly negatively correlated with all HRV variables at baseline, namely high-frequency heart rate variability (HF-HRV: P=.02), the root mean square of successive differences in normal heartbeat contractions (RMSSD: P=.02) and the variability of normal-to-normal interbeat intervals (SDNN: P=.04). At follow-up, only SDNN was significantly negatively correlated with age (P=.05). Levels of ASD symptoms were positively correlated with heart rate both before (P=.04) and after the intervention (P=.01). The majority (311/474, 65.6%) of reports from participants indicated that the devices helped when used. Difficulties with the use of some devices and problems with home testing of HRV were noted. These initial findings are discussed within the context of the strengths and challenges of remotely delivering a biofeedback intervention for people with ASD.

Conclusions

HRV biofeedback devices have shown promise in this pilot study. There is now a need for larger evaluation of biofeedback to determine which delivery methods achieve the greatest effect for people with ASD.

Trial Registration

ClinicalTrials.gov NCT04955093; https://clinicaltrials.gov/ct2/show/NCT04955093

The impact of COVID-19 on autism research: A cross-sectional analysis of discontinued or suspended clinical trials

Due to uncertainties associated with the COVID‐19 public health crisis, several clinical trials had to be withdrawn or postponed. Our investigation aimed to assess the rate of discontinuation of clinical trials focusing on Autism Spectrum Disorder. Of the 197 registered trials included in our systematic review, 15 (7.6%) were discontinued, with nearly half of these explicitly citing COVID‐19 as their reason for discontinuation. Pharmacological trials were six times more likely to be discontinued during the pandemic than non‐pharmacological studies. The difference between the likelihood of discontinuation was statistically significant (OR: 6.13; 95% CI: 1.22–30.71). There was no evidence of association between funding source and reasons for discontinuation. Limitations, along with implications for future trials are discussed.

Communication strategies used by adolescents with autism spectrum disorder and health professionals during treatment

Background

Autism spectrum disorder (ASD) is a developmental disorder, which affects social communicative capabilities. The research study has shown that ASD studies are focused on young children, excluding adolescents and adults: and it is understudied in the context of South Africa.

Objective

This study examined the interactional communication strategies of adolescents with ASD and health professionals during different treatment consultations to identify the interactional styles and communication strategies utilised by adolescents with ASD and their respective healthcare professionals in a variety of scenarios in order to generate management strategies for future healthcare professional communication training.

Method

A multi-case study design with a qualitative research approach has been used. Four adolescents with a moderate form of ASD and four health practitioners were interviewed. Participants were chosen by purpose and snowball sampling. Semi-structured, open-ended interviews were used for health professionals to collect information on the various interaction types and communication methods used, as well as their interpretations of these methods. Conversely, adapted face-to-face interviews were used to collect similar knowledge from adolescents themselves. The findings were qualitatively analysed on a case-by-case and cross-case basis by thematic analysis techniques.

Results

The findings indicated that ASD adolescents have interaction types that influence intervention to various degrees. In comparison to motor therapies such as occupational therapy and physiotherapy, interaction types have a greater impact on psychiatry and psychology, which depend mainly on verbal communication. Intuitively, to promote contact with these teens, all health practitioners changed their own interaction styles. They used techniques of clarification and repair. The therapists shared the intention to learn a range of successful ways to strengthen future experiences with ASD between themselves and adolescents.

Conclusion

The findings indicate that practitioners can benefit from altering their interaction styles, and that approaches for promoting successful interactions and in establishing rapport could be shared with other professionals in the future.

Proteomics of autism and Alzheimer's mouse models reveal common alterations in mTOR signaling pathway

Autism spectrum disorder (ASD) and Alzheimer's disease (AD) are two different neurological disorders that share common clinical features, such as language impairment, executive functions, and motor problems. A genetic convergence has been proposed as well. However, the molecular mechanisms of these pathologies are still not well understood. Protein S-nitrosylation (SNO), the nitric oxide (NO)-mediated posttranslational modification, targets key proteins implicated in synaptic and neuronal functions. Previously, we have shown that NO and SNO are involved in the InsG3680(+/+) ASD and P301S AD mouse models. Here, we performed large-scale computational biology analysis of the SNO-proteome followed by biochemical validation to decipher the shared mechanisms between the pathologies. This analysis pointed to the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway as one of the shared molecular mechanisms. Activation of mTOR in the cortex of both mouse models was confirmed by western blots that showed increased phosphorylation of RPS6, a major substrate of mTORC1. Other molecular alterations affected by SNO and shared between the two mouse models, such as synaptic-associated processes, PKA signaling, and cytoskeleton-related processes were also detected. This is the first study to decipher the SNO-related shared mechanisms between SHANK3 and MAPT mutations. Understanding the involvement of SNO in neurological disorders and its intersection between ASD and AD might help developing an effective novel therapy for both neuropathologies.

Exploratory Data Mining for Subgroup Cohort Discoveries and Prioritization

Finding small homogeneous subgroup cohorts in large heterogeneous populations is a critical process for hypothesis development in biomedical research. Concurrent computational approaches are still lacking in robust answers to the question "what hypotheses are likely to be novel and to produce clinically relevant results with well thought-out study designs?" We have developed a novel subgroup discovery method which employs a deep exploratory mining process to slice and dice thousands of potential subpopulations and prioritize potential cohorts based on their explainable contrast patterns and which may provide interventionable insights. We conducted computational experiments on both synthesized data and a clinical autism data set to assess performance quantitatively for coverage of pre-defined cohorts and qualitatively for novel knowledge discovery, respectively. We also conducted a scaling analysis using a distributed computing environment to suggest computational resource needs for when the subpopulation number increases. This work will provide a robust data-driven framework to automatically tailor potential interventions for precision health.

Selection and classification of gene expression in autism disorder: Use of a combination of statistical filters and a GBPSO-SVM algorithm

In this work, gene expression in autism spectrum disorder (ASD) is analyzed with the goal of selecting the most attributed genes and performing classification. The objective was achieved by utilizing a combination of various statistical filters and a wrapper-based geometric binary particle swarm optimization-support vector machine (GBPSO-SVM) algorithm. The utilization of different filters was accentuated by incorporating a mean and median ratio criterion to remove very similar genes. The results showed that the most discriminative genes that were identified in the first and last selection steps included the presence of a repetitive gene (CAPS2), which was assigned as the gene most highly related to ASD risk. The merged gene subset that was selected by the GBPSO-SVM algorithm was able to enhance the classification accuracy.

Reframing Autism: Young Adults With Autism Share Their Strengths Through Photo-Stories

A dearth of research describes the lives of young adults with autism spectrum disorder (ASD) from the perspectives of young adults themselves. We explored young adults' strengths using Photovoice, a method in which participants use images and discussions to express themselves. Images were purposefully chosen to help young people participate in the research process.

DESIGN AND METHODS

Eleven young adults captured their experiences growing up with ASD via images, and participated in three group photo discussions, an individual photo interview, and a photo exhibit. Qualitative data for analysis included session transcripts and photographs. We used strategies of theme analysis to understand participants' experiences.

RESULTS

The mean age of the sample was 20years, and 7 participants were male. Three sub-themes describe youth's strengths: 1) special interests that cultivated positive emotions and coping strategies; 2) skills and activities that evoked pride; and 3) reframing ASD as special versus a disadvantage.

CONCLUSIONS

The Photovoice method is well-suited to help young adults identify and express their strengths. Self-generated images and stories may offer a creative and effective form of communication for young adults with ASD.

PRACTICE IMPLICATIONS

Health care practitioners can capitalize on how Photovoice helps young adults express themselves by using images to understand their health priorities and involve young adults in their care plans. With images of strength, for example, nurses can build young adults' confidence and help these individuals to identify areas of their mental and physical lives in which they can thrive and experience improved quality of life.