Publications by authors named "Sirish Bennuri"

Epigenetic mechanisms, such as DNA methylation, regulate gene expression and play a role in the development of insulin resistance. This study evaluates how the BMI z-score (BMIz) and the homeostatic model assessment of insulin resistance (HOMA-IR), alone or in combination, relate to clinical outcomes and DNA methylation patterns in prepubertal children. DNA methylation in peripheral blood mononuclear cells (PBMCs) and clinical outcomes were measured in a cohort of 41 prepubertal children.

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Background: MicroRNAs (miRNAs) are important regulators of molecular pathways in psychiatric disease. Here, we examine differential miRNAs expression in lymphoblastoid cell lines (LCLs) derived from 10 individuals with autism spectrum disorder (ASD) and compare them to seven typically developing unrelated age- and gender-matched controls and 10 typically developing siblings. Small RNAseq analysis identified miRNAs, and selected miRNAs were validated using quantitative real-time polymerase reaction (qRT-PCR).

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Obesity is increasing worldwide in prepubertal children, reducing the age of onset of associated comorbidities, including type 2 diabetes. Sulfur-containing amino acids, methionine, cysteine, and their derivatives play important roles in the transmethylation and transsulfuration pathways. Dysregulation of these pathways leads to alterations in the cellular methylation patterns and an imbalanced redox state.

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We investigate the role of the mitochondrion, an organelle highly sensitive to environmental agents, in the influence of prenatal air pollution exposure on neurodevelopment and behavior in 96 children with autism spectrum disorder (ASD) [45 with neurodevelopmental regression (NDR); 76% Male; mean (SD) age 10 y 9 m (3 y 9 m)]. Mitochondrial function was assessed using the Seahorse XFe96 in fresh peripheral blood mononuclear cells. Second and third trimester average and maximal daily exposure to fine air particulate matter of diameter ≤2.

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Neurodevelopmental regression (NDR) is a subtype of autism spectrum disorder (ASD) that manifests as loss of previously acquired developmental milestones. Early life dysregulation of nutritional metals and/or exposure to toxic metals have been associated with ASD, but the underlying biological mechanisms by which metals influence neurodevelopment remain unclear. We hypothesize that metals influences neurodevelopment through dysregulation of bioenergetics.

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Autism spectrum disorder (ASD) is a behaviorally defined disorder that is now thought to affect approximately 1 in 69 children in the United States. In most cases, the etiology is unknown, but several studies point to the interaction of genetic predisposition with environmental factors. The immune system is thought to have a causative role in ASD, and specific studies have implicated T lymphocytes, monocytes, natural killer (NK) cells, and certain cytokines.

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Our previous research has shown that purified peripheral blood monocytes (PRMo) from individuals who are diagnosed with autism spectrum disorders (ASDs) and have innate immune abnormalities reveal altered interleukin-1ß (IL-1ß)/IL-10 ratios. We also found, in separate studies, that microRNA (miRNA) expression in PBMo and mitochondrial respiration in peripheral blood mononuclear cells (PBMCs) differed in the IL-1ß/IL-10-based ASD subgroups. This study explored whether serum miRNAs are associated with both altered innate immune responses and changes in mitochondrial respiration as a link of regulatory mechanisms for these two common abnormalities in ASD subjects.

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The peptide hormone oxytocin is an established regulator of social function in mammals, and dysregulated oxytocin signaling is implicated in autism spectrum disorder (ASD). Several clinical trials examining the effects of intranasal oxytocin for improving social and behavioral function in ASD have had mixed or inclusive outcomes. The heterogeneity in clinical trials outcomes may reflect large inter-individual expression variations of the oxytocin and/or vasopressin receptor genes OXTR and AVPR1A, respectively.

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Skeletal muscle mitochondrial respiration is thought to be altered in obesity, insulin resistance, and type 2 diabetes; however, the invasive nature of tissue biopsies is an important limiting factor for studying mitochondrial function. Recent findings suggest that bioenergetics profiling of circulating cells may inform on mitochondrial function in other tissues in lieu of biopsies. Thus, we sought to determine whether mitochondrial respiration in circulating cells [peripheral blood mononuclear cells (PBMCs) and platelets] reflects that of skeletal muscle fibers derived from the same subjects.

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We previously developed a lymphoblastoid cell line (LCL) model of mitochondrial dysfunction in autism spectrum disorder (ASD); some individuals with ASD showed mitochondrial dysfunction (AD-A) while other individuals (AD-N) demonstrated mitochondrial respiration similar to controls (CNT). To test the hypothesis that mitochondrial dysfunction could be a consequence of environmental exposures through chronic elevations in reactive oxygen species (ROS), we exposed LCLs to prolonged ROS. We also examined expression of metabolic regulatory genes and the modulating effect of the mechanistic target of rapamycin (mTOR) pathway.

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Autism spectrum disorder (ASD) is associated with multiple physiological abnormalities, including immune dysregulation, and mitochondrial dysfunction. However, an association between these two commonly reported abnormalities in ASD has not been studied in depth. This study assessed the association between previously identified alterations in cytokine profiles by ASD peripheral blood monocytes (PBMo) and mitochondrial dysfunction.

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Several studies associate autism spectrum disorder (ASD) pathophysiology with metabolic abnormalities related to DNA methylation and intracellular redox homeostasis. In this regard, three completed clinical trials are reexamined in this work: treatment with (i) methylcobalamin (MeCbl) in combination with low-dose folinic acid (LDFA), (ii) tetrahydrobiopterin, and (iii) high-dose folinic acid (HDFA) for counteracting abnormalities in the folate-dependent one-carbon metabolism (FOCM) and transsulfuration (TS) pathways and also for improving ASD-related symptoms and behaviors. Although effects of treatment on individual metabolites and behavioral measures have previously been investigated, this study is the first to consider the effect of interventions on a set of metabolites of the FOCM/TS pathways and to correlate FOCM/TS metabolic changes with behavioral improvements across several studies.

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Article Synopsis
  • Autism spectrum disorder (ASD) is currently diagnosed only through behavioral tests, but impaired folate metabolism and transsulfuration pathways are linked to the disorder.
  • A recent study used advanced analysis to successfully predict ASD diagnosis and explored various classification algorithms on existing metabolite data, validating findings with new ASD cohort data.
  • Results show high accuracy in classifying ASD cases, suggesting potential for a biochemical diagnostic test that could enhance understanding and diagnosis for a subset of the ASD population.
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Autism spectrum disorder (ASD) affects about 1 in 45 individuals in the United States, yet effective treatments are yet to be defined. There is growing evidence that ASD is associated with abnormalities in several metabolic pathways, including the inter-connected folate, methylation and glutathione pathways. Several treatments that can therapeutically target these pathways have been tested in preliminary clinical trials.

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Butyrate (BT) is a ubiquitous short-chain fatty acid (SCFA) principally derived from the enteric microbiome. BT positively modulates mitochondrial function, including enhancing oxidative phosphorylation and beta-oxidation and has been proposed as a neuroprotectant. BT and other SCFAs have also been associated with autism spectrum disorders (ASD), a condition associated with mitochondrial dysfunction.

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Propionic acid (PPA) is a ubiquitous short-chain fatty acid which is a fermentation product of the enteric microbiome and present or added to many foods. While PPA has beneficial effects, it is also associated with human disorders, including autism spectrum disorders (ASDs). We previously demonstrated that PPA modulates mitochondrial dysfunction differentially in subsets of lymphoblastoid cell lines (LCLs) derived from patients with ASD.

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The prevalence of autism spectrum disorder (ASD) is high, yet the etiology of this disorder is still uncertain. Advancements in genetic analysis have provided the ability to identify potential genetic changes that may contribute to ASD. Interestingly, several genetic syndromes have been linked to metabolic dysfunction, suggesting an avenue for treatment.

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Gastrointestinal (GI) symptoms are prevalent in autism spectrum disorder (ASD) but the pathophysiology is poorly understood. Imbalances in the enteric microbiome have been associated with ASD and can cause GI dysfunction potentially through disruption of mitochondrial function as microbiome metabolites modulate mitochondrial function and mitochondrial dysfunction is highly associated with GI symptoms. In this study, we compared mitochondrial function in rectal and cecum biopsies under the assumption that certain microbiome metabolites, such as butyrate and propionic acid, are more abundant in the cecum as compared to the rectum.

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Mitoplasticity occurs when mitochondria adapt to tolerate stressors. Previously we hypothesized that a subset of lymphoblastoid cell lines (LCLs) from children with autistic disorder (AD) show mitoplasticity (AD-A), presumably due to previous environmental exposures; another subset of AD LCLs demonstrated normal mitochondrial activity (AD-N). To better understand mitoplasticity in the AD-A LCLs we examined changes in mitochondrial function using the Seahorse XF96 analyzer in AD and Control LCLs after exposure to trichloroacetaldehyde hydrate (TCAH), an in vivo metabolite of the environmental toxicant and common environmental pollutant trichloroethylene.

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Treatment for mitochondrial dysfunction is typically guided by expert opinion with a paucity of empirical evidence of the effect of treatment on mitochondrial activity. We examined citrate synthase and Complex I and IV activities using a validated buccal swab method in 127 children with autism spectrum disorder with and without mitochondrial disease, a portion of which were on common mitochondrial supplements. Mixed-model linear regression determined whether specific supplements altered the absolute mitochondrial activity as well as the relationship between the activities of mitochondrial components.

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Autism spectrum disorder (ASD) is associated with physiological abnormalities, including abnormal redox and mitochondrial metabolism. Lymphoblastoid cell lines (LCLs) from some children with ASD exhibit increased oxidative stress, decreased glutathione redox capacity, and highly active mitochondria with increased vulnerability to reactive oxygen species (ROS). Because unaffected siblings (Sibs) of individuals with ASD share some redox abnormalities, we sought to determine whether LCLs from Sibs share ASD-associated mitochondrial abnormalities.

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Folate receptor α (FRα) autoantibodies (FRAAs) are prevalent in autism spectrum disorder (ASD). They disrupt the transportation of folate across the blood-brain barrier by binding to the FRα. Children with ASD and FRAAs have been reported to respond well to treatment with a form of folate known as folinic acid, suggesting that they may be an important ASD subgroup to identify and treat.

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Rationale: The Ca(2+) sensitivity of the myofilaments is increased in hypertrophic cardiomyopathy and other heart diseases and may contribute to a higher risk for sudden cardiac death. Ca(2+) sensitization increases susceptibility to reentrant ventricular tachycardia in animal models, but the underlying mechanism is unknown.

Objective: To investigate how myofilament Ca(2+) sensitization creates reentrant arrhythmia susceptibility.

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