COMING SOON

KRISTIN BRENNAND, PHD
TITLE: Studying the genomics of brain disorders using stem cells
ABSTRACT: Each person’s distinct genetics and environment predispose them to some phenotypes and confers resilience to others. How do all the individual variants across the genetic landscape combine to yield larger phenotypic impacts in aggregate? How does genetic variation govern the penetrance of deleterious mutations, variable expressivity, and pleiotropy? What is the role of the environment across the lifespan? Understanding how these elements interact will advance our knowledge of human development, aging, health, and disease. Our functional genomics approach integrates human induced pluripotent stem cell models with CRISPR-based genome engineering to introduce and reverse genetic variation, yielding precision models that can be combined with genetic and pharmacological screens. With this approach, we demonstrated that diverse risk variants share downstream convergent impacts, and that when added together, their combinatorial perturbations yield novel non-additive outcomes that cannot yet be predicted by individual manipulations alone. We seek to understand the genetic regulation of phenotype, and how it is impacted by developmental, cellular, and environmental contexts. Thus, rather than just characterize the impact of trait-associated variants, we seek to uncover modifiers that alter it. For example, we study how genotype-phenotype relationships vary across people and dynamic conditions. Our goal is to decipher the frameworks that buffer genetic risk, in order to confer biological resilience and promote healthy development. We are uniquely positioned to answer critical questions: How does the environment impact genetic regulation? Why are there marked sex effects across many human traits and diseases? What are the molecular mechanisms of resilience, whereby individuals with high genetic risk show no clinical manifestation of disease? Understanding the basic biology governing the complex interplay between genetic variants and the environment will springboard the development of novel, personalized approaches to improve health and prevent disease.

A case is presented of a 17 year old boy with responsive nerve stimulation (RNS) who underwent a treatment course of IVIG for severe OCD and Tourette’s syndrome. The RNS leads were placed in the centromedian nucleus of the thalamus bilaterally. The effect of IVIG treatment on RNS detections is reviewed and compared to his treatment response.

Given the overlapping neuropsychiatric symptoms and the presence of anti-neuronal autoantibodies in both ASD and Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infections (PANDAS), our study explored shared mechanisms to identify AE PANDAS subtypes in ASD.

Our investigation into the cross-reactive anti-neuronal and anti-microbial autoantibody responses associated with streptococcal and other childhood infections in ASD and PANDAS revealed that sera from both groups exhibited autoreactive anti-neuronal IgG against dopamine receptors, brain tubulin, and activated calcium/calmodulin-dependent protein kinase II (CaMKII) in human neuronal cells. The autoantibody-mediated dopamine receptor and CaMKII activation was mitigated by absorbing ASD and PANDAS sera with microbial polysaccharides or neuronal antigens. Abnormal antibody responses to streptococcal carbohydrate N-acetyl-beta-D-glucosamine were elevated in
both PANDAS and ASD subsets, alongside observed deficiencies in other microbial polysaccharide antibodies, defining potential immunoglobulin deficiencies and cross-reactivities in these diseases.

Further, we demonstrated shared gene expression signatures and enriched pathways mediated by ASD and PANDAS sera, suggesting similarities and differences in these neurological and psychiatric disorders, and the role of infection. Our findings suggest that molecular mimicry and immune cross-reactivity between host and pathogen contribute to the pathogenesis of infection-mediated autoimmune sequelae, resulting in
the emergence of tic and OCD behaviors in ASD and PANDAS.

Objectives/Methods: Loxapine 5-15mg daily resembles an atypical antipsychotic on PET studies. Preliminary evidence suggests a superior metabolic profile. We synthesize published evidence.

Results: PET scan studies demonstrated low dose loxapine blocks 5-HT2 and D2 receptors equipotently in vivo; loxapine action resembled atypical antipsychotic actions on dopamine and acetylcholine release in the nucleus accumbens and prefrontal cortex. Loxapine but NOT other antipsychotics produced neural sprouting in human pluripotent stem cells. A prospective open trial of low dose loxapine add-on for irritability in ASD found significant improvement, little or no weight gain, and increases in serum BDNF. A retrospective study of long-term low- dose loxapine in ASD found rates of EPS and TD lower than expected for classical antipsychotics. A retrospective chart review of loxapine 5-10mg daily add-on followed by atypical antipsychotic taper found mean 17-month weight LOSS of 5.7kg, mean BMI REDUCTION of 1.9, and mean triglyceride REDUCTION of 33.7mg/dl (p=.02). One subject discontinued insulin; 2 were tapered off metformin by endocrinologists.

Conclusions: Preliminary evidence justifies immediate pursuit of clinical trials of loxapine in ASD.

Our recent publication showed that neuronal IL- 1R1 (nIL-1R1) is important for cognition and social interaction in adult mice. The role of nIL-1R1 in neurodevelopment and related cognitive and affective functions is not known.

Here, we investigated the spatiotemporal expression patterns of nIL-1R1 during neurodevelopment and asked how nIL-1R1 might modulate neurodevelopment. We found that nIL-1R1 expression is very dynamic during brain development and changes dramatically in various brain regions including dentate gyrus of hippocampus (DG), dorsal raphe nucleus (DRN), ventral posteromedial (VPM), and posterolateral thalamic nuclei (VPL). These dynamic changes occurred in brain regions related to neurocircuits involved in the memory, sensory, and mood-regulation functions of the brain in a temporal spatial specific manner.

We assessed ELS- induced social interaction changes and found that nIL-1R1 is necessary for mediating maternal separation (MS, a well-established ELS paradigm) induced deficits in social interaction and social recognition later in life. Molecular analysis revealed a nIL-1R1-dependent acceleration of neuronal maturation in DG, somatosensory cortex, and frontal cortex in the early sensitive period after MS. In addition, we found that -FosB accumulated in granule neurons that express nIL-1R1 in DG after MS whereas this accumulation was not observed in controls. Our behavioral analysis suggests that nIL-1R1 is necessary for MS-induced deficits in social interaction and social recognition later in life.

These findings suggest that: 1) nIL-1R1 is tightly regulated during brain development correlating with its critical role in the control of neuronal maturation by non-neuroinflammatory neuro-immune activities, and 2) nIL-1R1 modulates the ELS-induced stress responses in DG which leads to long-lasting social interaction abnormalities by changing neuronal activity and/or plasticity in the DG

Individuals with childhood onset seizures without genetic abnormalities tended to have normal Cunningham panels or isolated elevations in anti-tubulin but not Cam Kinase II. Individuals with adolescent onset seizures, childhood onset seizures with genetic abnormalities or subclinical epileptiform discharges tended to have isolated elevations in Cam Kinase II without other autoantibodies elevated.

This study suggests that there are subgroups of children with ASD that have distinct patterns of neuroinflammation markers which fall into subgroups. One of these groups demonstrates elevation in CamKinase II without an identified autoantibody. This suggests that there are yet to be discovered autoantibodies or other inflammatory proteins that are driving Cam Kinase II elevations in this subgroup. Identifying these such proteins can help in the treatment of difficult to control seizures in ASD.

Recent research is providing evidence of metabolic disorders associated with a majority of children with ASD, including abnormalities in folate, mitochondrial and transmethylation/transsulfuration metabolism. All of these disorders have evidence of transgenerational inheritance without a clear genetic component. These pathways are highly influenced by environmental factors and are prime pathways to study to understand environmental x genetic (probably polygenic) interaction that contribute to ASD.

Studying these abnormalities from the top down (physiological abnormalities) rather than from the bottom up (genetic changes) may help uncover the complicated combination of factors which result in ASD and other neurodevelopmental disorders.

Research conducted over the past few decades have consistently shown dysfunctional metabolic signals involving redox metabolism in patients diagnosed with Autism Spectrum Disorder (ASD). To date there have been no double-blind case/control studies that seek to determine if abnormalities in 1-carbon folate metabolism, cellular methylation, and redox abnormalities are predictive of all forms of ASD compared to other types of developmental concerns (DD) that present early in life. BioROSA Technologies recently completed the first multicenter prospective double-blind case/control trial in which 163 children aged 18-60 months were enrolled. All children had a fasting blood draw and underwent diagnostic evaluation for ASD using DSM-5 criteria for diagnosis. All children had an assessment that included the Autism Diagnostic Observation Schedule (ADOS), Mullen Scales of Early Learning (MSEL), Vineland Adaptive Behavior Scales (VABS), and a full medical history and physical exam. The primary endpoint for the trial was to determine if metabolic biomarkers using a machine learning algorithm could accurately differentiate ASD from DD with accuracy >/= 80%. BioROSA test performance has demonstrated a positive signal in the MAP pilot trial. Details will be discussed.