Project description:Fetal alcohol spectrum disorder (FASD) is a common developmental behavioral disorder caused by maternal drinking during pregnancy. Children born with FASD often face additional stress, particularly maternal separation that adds yet additional deficits. The mechanism associated with this phenomenon is not known. Using a mouse model, prenatal ethanol exposure and maternal separation stress have resulted in behavioral deficits and the combination of treatments results in more than additive effects. In addition, behavioral alterations are associated with changes in hippocampal gene expression that persist into adulthood. What initiates and maintains these changes remains to be established and forms the focus of this research. Specifically, MeDIP-Seq was used to assess how changes in promoter DNA methylation are affected by the combination of prenatal ethanol exposure and maternal separation stress with the potential to affect gene expression. The novel results show different sets of genes implicated by promoter DNA methylation affected by both treatments independently, and a relatively unique set of genes affected by the combination of treatments. Prenatal ethanol exposure leads to altered promoter DNA methylation at genes important for brain function and transcriptional regulation. Maternal separation stress leads to changes at genes important for histone methylation and immune response, and the combination of two treatments results in DNA methylation changes at genes important for neuronal migration and immune response. Our dual results on gene expression and DNA methylation from the same samples have allowed comparison of the two observations. There is minimal reciprocal overlap between changes in promoter DNA methylation and gene expression, although overlapping genes tend to be critical for brain development and function. These results suggest that epigenetic mechanisms beyond promoter DNA methylation must be involved in lasting gene expression alterations leading to behavioral deficits implicated in FASD.

Project description:BACKGROUND & AIMS: Inflammatory Bowel Diseases (IBD), including Crohnâ??s disease and ulcerative colitis, are chronic illnesses that are thought to develop secondary to a pathologic interaction between the immune system and the intestinal microflora that is manifested by the gut mucosa. IBD has been recognized as disorders in which developmental epigenetic changes, such as DNA methylation, may play an important pathogenic role. DNA methylation can be influenced in mammals by dietary exposures. A methyl-donor diet has been specifically found to be effective in inducing permanent changes in DNA methylation at certain genomic loci in murine models. Importantly, the methyl-donor substances utilized are routinely incorporated into prenatal micronutrient supplements for humans. In this study we addressed whether maternal exposure to a methyl-donor diet induces prolonged alterations in offspring colitis susceptibility and whether it leads to stable colonic mucosal epigenetic changes and gene expression alterations in mice. We also assessed whether the maternal methyl-donor diet induced persistent changes in the colonic microbiota in the offspring. METHODS: Colonic mucosa from offspring of mothers fed a methyl donor diet (MD) or control diet was interrogated by methylation specific amplification microarray (MSAM) at postnatal day 30 (P30) and P90 to screen for changes in DNA methylation, with bisulfite pyrosequencing validation. Transcriptomic changes in the same tissue were analyzed by microarray expression profiling and real time RT-PCR. The mucosal microbiome was studied by high throughput, detailed pyrosequencing of 16S rRNA. RESULTS: MD exposure during prenatal and early development lead to a significant increase in colitis susceptibility that persisted even after 69 days of diet reversal (P90). MD exposure also influenced DNA methylation and expression at select genomic loci. Overlap between DNA methylation and gene expression changes was confirmed at Ppara, a gene previously implicated in murine colitis. Metagenomic analyses failed to reveal consistent bacteriomic differences between the P30 and P90 age groups. CONCLUSIONS: Prenatal and early developmental exposure to MD induces increased colitis susceptibility, mucosal epigenomic, and transcriptomic changes that do not appear to associate with consistent microbiomic alterations. These findings underscore the importance of maternal nutrition on offspring colitis susceptibility in mammals and implicate the importance of the associated mucosal epigenetic modification. Our results bare potentially significant public health relevance as well. 4 independent MD versus control comparisons at P90 were performed as follows. RNA (0.4ug) samples were processed and labelled with Cy3 and Cy5 (Quick Amp labelling kit, two color, Agilent technologies) and 4 independent P90 MD to P90 control comparisons were done on Agilent technologies 4x44k whole genomic expression microarray G2519F, Amadid:014868)

Project description:Background: How prenatal smoke exposure affects DNA methylation leading to atopic disorders remains to be addressed. Epigenetic biomarkers informative of prenatal smoke exposure and atopic disorders are wanting. Since most children suffering from atopic dermatitis (AD) continue to develop asthma later in life, we explored whether prenatal smoke exposure e induces DNA methylation and searched for predictive epigenetic biomarkers for smoke related atopic disorders. Methods: Methylation differences associated with smoke exposure were screened by Illumina methylation panel for children from the Taiwan birth panel study cohort initially. Information about development of atopic dermatitis (AD) and risk factors were collected. Cord blood cotinine levels were measured to represent prenatal smoke exposure. CpG loci that demonstrated a statistically significant difference in methylation were validated by methylation-dependent fragment separation (MDFS). Differential methylation in three genes (TSLP, GSTT1, and CYB5R3) was identified through the screen and their functions were investigated. Results: Among these, only thymic stromal lymphopoietin (TSLP) gene displayed significant difference in promoter methylation percentage after being validated by MDFS (p=0.029). TSLP gene was further investigated in a larger sample of 92 children from the cohort. Methylation status of the TSLP 5′-CpG island (CGI) was found to be significantly associated with prenatal smoke exposure (OR=3.59, 95%CI=1.49-8.64; cotinine level 0.10 ng/ml, sensitivity= 77%; specificity = 61%) and with AD (OR=4.77, 95%CI=1.47-15.53). The degree of TSLP 5′CGI methylation inversely correlated with TSLP protein expression levels (per unit: β=－6.69 ng/ml; 95% CIs, －12.80~－0.59; p=0.032). Conclusions: The effect of prenatal tobacco smoke exposure on the risk for AD may be mediated through DNA methylation. Cord blood methylated TSLP 5′CGI may be a potential epigenetic biomarker for environmentally-related atopic disorders. The buffy coat and plasma samples were separated and stored at −80°C. DNA (100 ng-500 ng) was extracted from cord white blood cells. Microarrays have been performed to investigate fourteen samples, which were classified as two groups according to cotinine exposure dosage (7 versus 7 : high exposure verses low exposure).

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