In 2021, ARI awarded grants to fund innovative research that holds realistic promise in impacting the lives of those on the autism spectrum. Since the onset of the pandemic in 2020, we have been assisting many of our colleagues worldwide adjust their research plans so they can continue their efforts with minimal interruptions.

The Autism Research Institute (ARI) conducts, sponsors, and supports research on the underlying causes of, and treatments for, autism. In order to provide parents and professionals with an independent, unbiased assessment of causal and treatment efficacy issues, ARI seeks no financial support from government agencies or drug manufacturers.

2021

Cross-talk between food-borne Lactiplantibacillus (Lpb.) plantarum and the endocannabinoid system towards Autism Spectrum Disorder

Natalia Battista, PhD
University of Teramo Faculty of Bioscience and Technology for Food, Agriculture and Environment

The Endocannabinoid System (ECS) is one of the major modulators among the signaling pathways involved in the microbiota–gut–brain axis and the potential role of this endogenous system has been reported also in neurodevelopmental disorders, such as Autism Spectrum Disorders (ASD).

The general aim of this project is to evaluate the suitability of food-borne Lactiplantibacillus (Lpb.) plantarum strains, a versatile and robust dominant species in fermented foods, as a putative strategy to ameliorate ASD-symptoms through the involvement of the ECS.

To test our hypothesis, we propose to feed Lpb. plantarum strains to mice of two ASD mouse models, one based on genetic and one based on environmental etiology, in order to verify whether the treatment rescues specific behavioral deficits, restores levels of inhibitory and excitatory synaptic markers and modulates the ECS signaling. Levels of cytokines, endocannabinoids and gut barrier function will be also measured in the gastrointestinal (GI) tract to evaluate the impact of the host-microbe interaction in counteracting ASD-GI symptoms.

The multidisciplinary approach of this project will make it possible to advance in the field of microbial interventions with promising therapeutical value for the amelioration of ASD symptoms, by unveiling the possible role of the ECS in the communication mechanisms within the microbiota–gut–brain axis.

The role of male-specific perinatal sex hormones in the development of sex-biased mitochondrial and social behavioral dysregulation

Evan Bordt, PhD
Massachusetts General Hospital

Neuroimmune alterations such as aberrant activation of the innate immune cells of the brain, microglia, are recognized in individuals diagnosed with Autism Spectrum Disorders (ASD). Using mouse models, we have found that immune challenges such as infection in the perinatal period (time surrounding birth) lead to alterations in social behaviors only in male mice, consistent with the strong male bias in the incidence of ASD. Additionally, we have found that there are male-specific alterations in the function of mitochondria, the primary cellular energy producer, specifically within neuroimmune cells (microglia).

To begin to understand what could underlie these perinatal sex differences, we explored a sex-specific developmental program that is well-characterized during the perinatal period. There is a surge of gonadal hormones that occurs only in males during a critical period of brain development, and it is this hormone surge that is responsible for ‘masculinizing’ the male brain. When we injected female mouse pups with this male-typical gonadal sex hormone, we were able to induce male-like susceptibility to behavioral and cellular changes in response to immune challenge. These results suggest that the perinatal hormone surge plays an important role in inducing this male-biased vulnerability.

The goal of this study is to understand how gonadal sex hormones present only in males during perinatal brain organization result in male neuroimmune and behavioral vulnerabilities to early-life immune challenges. We plan to achieve our aim through manipulation of sex hormone receptors specifically on microglia in the brain and will test the impacts of these manipulations on microglial, mitochondrial, and behavioral outcomes. These results will provide a crucial step towards understanding the nature of perinatal influences on sex-biased susceptibilities to ASD.

Targeting cerebellar inflammation to improve autism-related behaviors in Shank3b mutant mice, a model of Autism Spectrum Disorder

Yuri Bozzi, PhD
University of University of Trento CIMeC Center for Mind/Brain Sciences

Immune dysfunction recently emerged as a major contributor to neurodevelopmental deficits observed in people with ASD. In particular, a strong inflammatory state is associated with ASD and likely supports its pathogenesis. Several reports showed that the cerebellum is structurally and functionally abnormal in autistic individuals, and signs of inflammation have been reported in the cerebellum of autistic people and ASD mouse models. Whether cerebellar inflammation may contribute to social and sensory deficits in ASD is still unknown. In this project, we aim to target cerebellar inflammation in a well-established mouse model of ASD, i.e. mice lacking the SHANK3B gene (Shank3b-/- mice). Control and mutant mice will be chronically treated with an anti-inflammatory drug starting from 1 or 6 months of age. After treatment, we will assess social, motor, and sensory-dependent behaviors and measure the expression of pro-inflammatory markers in the cerebellum of treated and untreated control and mutant mice. These studies will allow us to determine whether a systemic anti-inflammatory treatment in young and adult mice is able to rescue social and sensorimotor deficits, along with their molecular underpinnings, in Shank3b-/- mice.

Cerebellar Circuits in 3D: Screening autism-associated genes in cleared brains with in utero CRISPR genome editing

Cheryl Brandenburg, PhD
University of Maryland School of Medicine

Imaging studies and studies of human postmortem autism brains have consistently revealed cerebellar differences, specifically with alterations in Purkinje cell number and transcriptional profiles. This proposal aims to characterize effects of autism-associated genes on cerebellar microcircuitry by using in utero electroporation, whole brain clearing/staining and 3D light sheet microscopy, beginning with the cadherin family. The long-term goal is to develop a detailed map of cerebellar microcircuitry which will be used as a reference model to screen for circuit deficits with additional gene families. A high-resolution understanding of circuit development and structure will provide insight toward the implementation of novel interventions to benefit those on the spectrum.

Effect of Microbiota Transfer Therapy on Gut Mycobiota in Adults with ASD

Rosa Krajmalnik-Brown, PhD
Arizona State University

Several studies have shown that children with Autism Spectrum Disorder (ASD) have altered gut microbiota compared to Typically Developing (TD) controls. This alteration in the gut, not only changes bacterial composition but also fungal community. Culture and sequencing methods have demonstrated Candida (especially C. albicans) higher abundance in children with Autism vs. TD and correlated with ASD related symptoms. Previously, we showed that Microbiota Transfer Therapy (MTT) in children with ASD improved Gastro-Intestinal (GI) and ASD-related symptoms and increased bacterial diversity. However, no one has investigated the effects of MTT on the fungal community. We hypothesize that MTT may also have an important effect on fungal/Candida abundance in ASD. We propose a pilot study leveraging our adults MTT on going trial (a randomized, double-blind placebo-controlled) to study changes in the fungal (Candida) community during vancomycin treatment, and before & after MTT. This study will provide insight into fungi abundance, possible interactions with bacteria, and their association with GI- and ASD-related symptoms.

Development of a biosensor for visualization of PTEN activity in the brain

Tal Laviv, PhD
Tel Aviv University

In the past decade, numerus mutations in genes were closely associated with Autism Spectrum Disorder (ASD). One prominent example is the gene Phosphatase and tensin homolog deleted on chromosome 10 (PTEN). Numerus mutations which affect PTEN function are frequent in children diagnosed with ASD. Due to this strong link between PTEN and ASD, it is critical to understand how normal brain function is regulated by PTEN. Unfortunately, there are currently no available methods to measure PTEN function within the living brain. To solve this, we will engineer a new biosensor, a sensitive molecular ruler for PTEN activity. We will use this biosensor in combination with advanced microscopy to decipher the function of PTEN in living brain tissue. These novel technological advancements will be fundamental to unravel the core mechanisms which lead to neurological dysfunction in ASD.