A Network Analysis of Epigenetic and Transcriptional Regulation in a Neurodevelopmental Rat Model of Schizophrenia With Implications for Translational Research.

Prenatal administration of mitotoxin methylazoxymethanol acetate (MAM) in rats produces behavioral, pharmacological, and anatomical abnormalities once offspring reach adulthood, thus establishing a widely used neurodevelopmental model of schizophrenia. However, the molecular aspects underlying this disease model are not well understood. Therefore, this study examines epigenetic and transcriptional dysregulation in the prefrontal cortex and hippocampus of MAM rats as these are brain regions closely associated with schizophrenia pathogenesis. Upon sequencing messenger and microRNA (mRNA and miRNA, respectively), differential expression was revealed in the prefrontal cortex and hippocampus between MAM- and saline-treated rats; sequencing data were validated by qualitative real-time polymerase chain reaction. Bioinformatic analyses demonstrated that the differentially expressed (DE) genes were strongly enriched in interactive pathways related to schizophrenia, including chemical synaptic transmission, cognition, and inflammatory responses; also, the potential target genes of the DE miRNAs were enriched in pathways related to synapses and inflammation. The blood of schizophrenia patients and healthy controls was further analyzed for several top DE mRNAs: DOPA decarboxylase, ret proto-oncogene, Fc receptor-like 2, interferon lambda receptor 1, and myxovirus (influenza virus) resistance 2. The results demonstrated that the expression of these genes was dysregulated in patients with schizophrenia; combining these mRNAs sufficiently differentiated schizophrenia patients from controls. Taken together, this study suggests that the MAM model has the potential to reproduce hippocampus and prefrontal cortex abnormalities, relevant to schizophrenia, at the epigenetic and transcriptional levels. These data also provide novel targets for schizophrenia diagnoses and treatments.

Genetic predictors of celiac disease, lactose intolerance, and vitamin D function and presence of peptide morphins in urine of children with neurodevelopmental disorders.

Gastrointestinal disturbances, nutritional deficiencies, and food intolerances are frequently observed in children with neurodevelopmental disorders (NDD). To reveal possible association of celiac disease risk variants (HLA-DQ), lactose intolerance associated variant (LCT-13910C>T) as well as variant associated with vitamin D function (VDR FokI) with NDD, polymerase chain reaction-based methodology was used. Additionally, intestinal peptide permeability was estimated in NDD patients and healthy children by measuring the level of peptides in urine using high-performance liquid chromatography. Levels of opioid peptides, casomorphin 8, and gluten exorphin C were significantly elevated in urine samples of NDD patients (P = 0.004 and P = 0.005, respectively), but no association of genetic risk variants for celiac disease and lactose intolerance with NDD was found. Our results indicate that increased intestinal peptide permeability observed in analyzed NDD patients is not associated with genetic predictors of celiac disease or lactose intolerance. We have also found that FF genotype of VDR FokI and lower serum levels of vitamin D (25-OH) showed association with childhood autism (CHA), a subgroup of NDD. We hypothesize that vitamin D might be important for the development of CHA.

Neurodevelopment in 3-4 year old children exposed to maternal hyperglycemia or adiposity in utero.

BACKGROUND: Prenatal exposure to maternal metabolic complications has been linked to offspring neurodevelopmental problems. However, no studies investigating these links have examined the role of maternal prenatal diet. AIMS: To determine if prenatal exposure to maternal adiposity or hyperglycemia is associated with neurodevelopmental problems in 3-4 year old children, and if links persist following adjustment for confounding variables, including prenatal diet. METHOD: 808 mother-child pairs from the Maternal-Infant Research on Environmental Chemicals-Child Development Plus cohort were used to examine associations between pre-pregnancy body mass index (BMI), hyperglycemia and offspring verbal, performance and full-scale IQ scores, as well as internalizing and externalizing problems. Associations were examined before and after adjustment for prenatal diet along with home environment, maternal depression, education and prenatal smoking. Semi-partial correlations were examined post-hoc to assess the impact of each confounder in the adjusted models. RESULTS: In the unadjusted models, BMI and hyperglycemia predicted lower verbal and full-scale IQ. BMI was also linked to externalizing problems. However, associations were not significant after adjustment. In adjusted models, post-hoc analysis revealed that prenatal diet and home environment accounted for significant variance in verbal and full-scale IQ. The home environment and maternal depression accounted for significant variance in externalizing problems. CONCLUSION: In the adjusted models, maternal metabolic complications were not associated with offspring neurodevelopment. Even while adjusting for well-known risk factors for adverse offspring cognition (home environment, maternal depression), we show for the first time that maternal prenatal diet is an important confounder of the links between maternal metabolic complications and offspring cognition.

The Impact of Systemic Inflammation on Neurodevelopment.

Inflammatory mediators affect the brain during development. Neurodevelopmental disorders such as autism spectrum disorders, cognitive impairment, cerebral palsy, epilepsy, and schizophrenia have been linked to early life inflammation. Recent advances have shown the effects of systemic inflammation on children's neurodevelopment. We discuss the potential mechanisms by which inflammatory molecules can exert their effects on the developing brain and consider the roles of MHC class I molecules, the HPA axis, glial cells, and monoamine metabolism. Methods to prevent the effects of cytokine imbalance may lead to the development of new therapeutics for neuropsychiatric disorders. Future research should focus on identifying at-risk individuals and early effective interventions to prevent long-term neurodevelopmental disabilities.

Non-invasive prenatal diagnosis of paternally inherited disorders from maternal plasma: detection of NF1 and CFTR mutations using droplet digital PCR.

BACKGROUND: To limit risks of miscarriages associated with invasive procedures of current prenatal diagnosis practice, we aim to develop a personalized medicine-based protocol for non-invasive prenatal diagnosis (NIPD) of monogenic disorders relying on the detection of paternally inherited mutations in maternal blood using droplet digital PCR (ddPCR). METHODS: This study included four couples at risk of transmitting paternal neurofibromatosis type 1 (NF1) mutations and four couples at risk of transmitting compound heterozygous CFTR mutations. NIPD was performed between 8 and 15 weeks of gestation, in parallel to conventional invasive diagnosis. We designed specific hydrolysis probes to detect the paternal mutation and to assess the presence of cell-free fetal DNA by ddPCR. Analytical performances of each assay were determined from paternal sample, an then fetal genotype was inferred from maternal plasma sample. RESULTS: Presence or absence of the paternal mutant allele was correctly determined in all the studied plasma DNA samples. CONCLUSIONS: We report an NIPD protocol suitable for implementation in an experienced laboratory of molecular genetics. Our proof-of-principle results point out a high accuracy for early detection of paternal NF1 and CFTR mutations in cell-free DNA, and open new perspectives for extending the technology to NIPD of many other monogenic diseases.

The impacts of maternal iron deficiency and being overweight during pregnancy on neurodevelopment of the offspring.

Both maternal Fe deficiency (ID) and being overweight or obese (Ow/Ob, BMI≥25 kg/m2) may negatively affect offspring brain development. However, the two risk factors correlate and their independent effects on infant neurodevelopment are unclear. PREOBE is a prospective observational study that included 331 pregnant Spanish women, of whom 166 had pre-gestational Ow/Ob. Fe status was analysed at 34 weeks and at delivery, and babies were assessed using Bayley III scales of neurodevelopment at 18 months. In confounder-adjusted analyses, maternal ID at 34 weeks was associated with lower composite motor scores at 18 months (mean 113·3 (sd 9·9) v. 117·1 (sd 9·2), P=0·039). Further, the offspring of mothers with ID at delivery had lower cognitive scores (114·0 (sd 9·7) v. 121·5 (sd 10·9), P=0·039) and lower receptive, expressive and composite (99·5 (sd 8·6) v. 107·6 (sd 8·3), P=0·004) language scores. The negative associations between maternal ID at delivery and Bayley scores remained even when adjusting for maternal Ow/Ob and gestational diabetes. Similarly, maternal Ow/Ob correlated with lower gross motor scores in the offspring (12·3 (sd 2·0) v. 13·0 (sd 2·1), P=0·037), a correlation that remained when adjusting for maternal ID. In conclusion, maternal ID and pre-gestational Ow/Ob are both negatively associated with Bayley scores at 18 months, but independently and on different subscales. These results should be taken into account when considering Fe supplementation for pregnant women.

Neuropsychomotor development and genomic stability associated to folate and blood iron levels in preschool children / Desenvolvimento neuropsicomotor e estabilidade genômica associados aos níveis de folato e ferro sanguíneos de pré-escolares

Abstract Objectives: to evaluate the neuropsychomotor development and the genomic stability associated to folate and blood iron levels in preschool children. Methods: a cross-sectional study in which evaluated the biochemical exams (complete hemogram, serum ferritin, iron and folate), neuropsychomotor development (Denver II Test) and genotoxicity (micronuclei cytome in buccal mucosa cells) of 55 children aging 36-59 months old. Student´s T test, Kruskal-Wallis and Pearson's or Spearman's correlation tests were applied with a significance level of p<0.05 for data analysis. Results: the prevalence of anemia was 1.8%. The Denver II test classified 32.7% of the children as normal and 67.3% were suspected of having a delay. The children suspected of having a delay presented a slight reduction on hemoglobin and hematocrit (p=0.05 and p=0.14), intermediate reduction on iron and folate (p=0.29 and p=0.23) and a notable reduction on ferritin (p=0.03). Folate and iron were significantly associated to the frequency of cells with DNA damages (p<0.05). The frequency of binucleated cells was positively associated to the Red Cell Distribution Width (RDW) (r=0.56; p=0.02) in children without a delay and negatively with folate (r=-0.334; p=0.047) in children with a delay. Conclusions: this study showed a low prevalence of anemia, but a high rate of children suspected of having a neuropsychomotor, possibly associated to low ferritin levels. Additionally, iron and folate were associated to DNA damage which may have contributed to the psychomotor development delay.

Resumo Objetivos: avaliar o desenvolvimento neuropsicomotor e a estabilidade genômica associados ao folato e ferro sanguíneos em pré-escolares. Métodos: estudo transversal, no qual avaliou-se exames bioquímicos (hemograma completo, ferritina sérica, ferro e folato), desenvolvimento neuropsicomotor (Teste Denver II) e genotoxicidade (citoma de micronúcleos em células bucais esfoliadas) de 55 crianças com 36-59 meses de idade. Para a análise dos dados, empregou-se os testes T de Student, Kruskal-Wallis e correlação de Pearson ou Spearman, com nível de significância de p<0,05. Resultados: a prevalência de anemia foi de 1,8%. Pelo teste de Denver II foram classificadas 32,7% das crianças como normais e 67,3% como suspeita de atraso. As crianças com suspeita de atraso apresentaram pequena redução no hematócrito e hemoglobina (p=0,05 e p=0,14), redução intermediária de ferro e folato (p=0,29 e p=0,23) e redução marcante de ferritina (p=0,03). Ferro e folato associaram-se significativamente com a frequência de células com lesões no DNA (p<0,05). A frequência de células binucleadas associou-se positivamente com Red Cell Distribution Width (RDW) (r=0,56; p=0,02), nas crianças sem atraso e negativamente com folato (r=-0,33; p=0,05), nas crianças com atraso. Conclusões: este estudo mostrou baixa prevalência de anemia, mas elevada taxa de crianças com suspeita de atraso neuropsicomotor, possivelmente associada com baixos níveis de ferritina. Ademais, observou-se associação entre ferro e folato com dano no DNA, o que pode ter contribuído para o atraso neuropsicomotor.

Plasma Aluminum Concentrations in Pediatric Patients Receiving Long-Term Parenteral Nutrition.

BACKGROUND: Patients receiving long-term parenteral nutrition (PN) are at increased risk of aluminium (Al) toxicity because of bypass of the gastrointestinal tract during PN infusion. Complications of Al toxicity include metabolic bone disease (MBD), Al-associated encephalopathy in adults, and impaired neurological development in preterm infants. Unlike the United States, there are no regulations regarding Al content of large- and small-volume parenterals in Canada. We, therefore, aimed to present our data on plasma Al concentration and Al intake from our cohort of pediatric patients receiving long-term PN. METHODS: Plasma Al concentration was retrospectively gathered from the patient charts of all 27 patients with intestinal failure (IF) receiving long-term PN at The Hospital for Sick Children, Toronto, Canada, and compared with age- and sex-matched controls recruited for comparison. In addition, Al concentration was measured in PN samples collected from 10 randomly selected patients with IF and used to determine their Al intake. RESULTS: The plasma Al concentration of patients with IF receiving long-term PN was significantly higher than that of control participants (1195 ± 710 vs 142 ± 63 nmol/L; P < .0001). In the subgroup of 10 patients for whom Al intake from their PN solution was determined, mean ± SD Al intake from PN was 15.4 ± 15 µg/kg, 3 times the Food and Drug Administration upper recommended intake level, and Al intake was significantly related to plasma Al concentration (P = .02, r (2) = 0.52). CONCLUSION: Pediatric patients receiving long-term PN for IF in Canada are at risk for Al toxicity.