25th Annual Computational Neuroscience Meeting: CNS-2016

Abstracts of the 25th Annual Computational Neuroscience Meeting: CNS-2016 Seogwipo City, Jeju-do, South Korea. 2–7 July 201

Genotoxicity and acute and subchronic toxicity studies of a standardized methanolic extract of Ficus deltoidea leaves

OBJECTIVE: Ficus deltoidea leaves have been used in traditional medicine in Southeast Asia to treat diabetes, inflammation, diarrhea, and infections. The present study was conducted to assess the genotoxicity and acute and subchronic toxicity of a standardized methanol extract of F. deltoidea leaves. METHODS: Sprague Dawley rats were orally treated with five different single doses of the extract and screened for signs of toxicity for two weeks after administration. In the subchronic study, three different doses of the extract were administered for 28 days. Mortality, clinical signs, body weight changes, hematological and biochemical parameters, gross findings, organ weights, and histological parameters were monitored during the study. Genotoxicity was assessed using the Ames test with the TA98 and TA100 Salmonella typhimurium strains. Phytochemical standardization was performed using a colorimeter and high-performance liquid chromatography. Heavy metal detection was performed using an atomic absorption spectrometer. RESULTS: The acute toxicity study showed that the LD(50) of the extract was greater than 5000 mg/kg. In the subchronic toxicity study, there were no significant adverse effects on food consumption, body weight, organ weights, mortality, clinical chemistry, hematology, gross pathology, or histopathology. However, a dose-dependent increase in the serum urea level was observed. The Ames test revealed that the extract did not have any potential to induce gene mutations in S. typhimurium, either in the presence or absence of S9 activation. Phytochemical analysis of the extract revealed high contents of phenolics, flavonoids, and tannins. High-performance liquid chromatography analysis revealed high levels of vitexin and isovitexin in the extract, and the levels of heavy metals were below the toxic levels. CONCLUSION: The no-observed adverse effect level of F. deltoidea in rats was determined to be 2500 mg/kg

Circulating Plasma Extracellular Microvesicle MicroRNA Cargo and Endothelial Dysfunction in Children with Obstructive Sleep Apnea

Rationale: Obese children are at increased risk for developing obstructive sleep apnea (OSA), and both of these conditions are associated with an increased risk for endothelial dysfunction (ED) in children, an early risk factor for atherosclerosis and cardiovascular disease. Although weight loss and treatment of OSA by adenotonsillectomy improve endothelial function, not every obese child or child with OSA develops ED. Exosomes are circulating extracellular vesicles containing functional mRNA and microRNA (miRNA) that can be delivered to other cells, such as endothelial cells. Objectives: To investigate whether circulating exosomal miRNAs of children with OSA differentiate based on endothelial functional status. Methods: Obese children (body mass index z score >1.65) and nonobese children were recruited and underwent polysomnographic testing (PSG), and fasting endothelial function measurements and blood draws in the morning after PSG. Plasma exosomes were isolated from all subjects. Isolated exosomes were then incubated with confluent endothelial cell monolayer cultures. Electric cell-substrate impedance sensing systems were used to determine the ability of exosomes to disrupt the intercellular barrier formed by confluent endothelial cells. In addition, immunofluorescent assessments of zonula occludens-1 tight junction protein cellular distribution were conducted to examine endothelial barrier dysfunction. miRNA and mRNA arrays were also applied to exosomes and endothelial cells, and miRNA inhibitors and mimics were transfected for mechanistic assays. Measurements and Main Results: Plasma exosomes isolated from either obese children or nonobese children with OSA were primarily derived from endothelial cell sources and recapitulated ED, or its absence, in naive human endothelial cells and also in vivo when injected into mice. Microarrays identified a restricted signature of exosomal miRNAs that readily distinguished ED from normal endothelial function. Among the miRNAs, expression of exosomal miRNA-630 was reduced in children with ED and normalized after therapy along with restoration of endothelial function. Conversely, transfection of exosomes from subjects without ED with an miRNA-630 inhibitor induces the ED functional phenotype. Gene target discovery experiments further revealed that miRNA-630 regulates 416 gene targets in endothelial cells that include the Nrf2, AMP kinase, and tight junction pathways. Conclusions: These observations elucidate a novel role of exosomal miRNA-360 as a putative key mediator of vascular function and cardiovascular disease risk in children with underlying OSA and/or obesity, and identify therapeutic targets