Early life Lead exposure causes distinct gender specific changes in the DNA methylation profile of DNA extracted from dried blood spots
ABSTRACT: Study of influence of gender and Lead(Pb) exposure on DNA methylation for whole blood measured in dried blood spots for a Detroit cohort of child between the age of 3 months to 5years DNA methylation profiling of dried blood spots for a Detroit cohort of child between the ages of 3 months to 5 years Differential methylation study
Project description:We tested a hypothesis that prenatal alcohol exposure may lead to epigenetic alterations to the DNA resulting in attentional and cognitive alterations of the children. 6-9 year old children school children of the Franconian Cognition and Emotion Studies (FRANCES) cohort which were tested for an objective marker of PAE, ethyl glucuronide (EtG) in meconium at birth. 32 newborns were found to be exposed to alcohol with a threshold above 30 ng/g (EtG+) but without a FAS diagnosis. DNA for methylation analysis was extracted from buccal cells, DNA methylation was analyzed using the Infinium Human Methylation 450K BeadChip array (Illumina).
Project description:DNA methylation patterns are set up in a relatively fixed programmed manner during normal embryonic development and are then stably maintained. Using genome-wide analysis, we have discovered a postnatal pathway involving gender-specific demethylation that occurs exclusively in the male liver. This demodification is programmed to take place at tissue-specific enhancer sequences, and our data show that the methylation state at these loci is associated with and appears to play a role in the transcriptional regulation of nearby genes. This process is mediated by the secretion of testosterone at the time of sexual maturity, but the resulting methylation profile is stable and therefore can serve as an epigenetic memory even in the absence of this inducer. These findings add a new dimension to our understanding of the role of DNA methylation in vivo and provide the foundations for deciphering how environment can impact on the epigenetic regulation of genes, in general. DNA methylation profile of male and female mouse and Human tissues was generated using the RRBS protocol followed by deep sequncing. Whole genome DNA methylation profile using deep sequencing was genereted for male and female mouse tissues. RNAseq was performed on male and female mouse tissues.
Project description:To identify genes that are downstream of gonadal hormones and that control dimorphic behaviors, we used a MEEBO array platform to profile gene expression of adult male and female hypothalamus against a whole brain reference sample. The experimental design allowed us to identify genes that are upreguated in the hypothalamus compared to the whole brain and are dimorphically expressed between the two sexes. In situ hybridization of candiate genes were carried out to validate the dimorphic expression of these genes in the hypothalamus. Array results were used to create a list of genes to screen by in situ hybridization. For each normalization method, a list of genes that were upregulated in the male or the female was created, and a gene had to be on a set number of these individual normalization lists in order to be considered for screening. A similar method was used to create a list of hypothalamic upregulated genes. The final screening list was comprised of genes that were upregulated in the male or female as well as in the hypothalamus. If in situ hybridization proved that the gene was upregulated in the male or female brain, we concluded that that transcript was differentially expressed. No one normalization method was weighted over another, and the array results were used to create a screening list for in situ hybridizations. Hypothalami from 4 adult animals of each sex were microdissected and pooled for each experimental sample and the whole brain plus pituitary from one male and one female were pooled to provide the reference sample. Each set of samples (male and female) was hybridized to two arrays to provide two technical replicates for each set of samples taken. A total of three sets of samples were taken (three biological replicates). For the "_amp" Samples, source (hypothalamus and whole brain) mRNA was amplified using T7 based method. For this set, data were not normalized, rather the raw intensities were used to calculate ratios. Candidate genes from this study was also included in final list in situ screening.
Project description:Determine methylation pattern in PDAC a genome-wide analysis was performed in a cohort of 167 PDAC and 29 adjacent pancreatic tissues samples using the Infinium 450k methylation arrays (Illumina). 167 pancreatic tumors (PDAC) x 29 adjacent -non tumor samples.
Project description:We report that the DNA methylation profile of a child’s neonatal whole blood can be significantly influenced by his or her mother’s neonatal blood lead levels (BLL). We recruited 35 mother-infant pairs in Detroit and measured the whole blood lead (Pb) levels and DNA methylation levels at over 450,000 loci from current blood and neonatal blood from both the mother and the child. We found that mothers with high neonatal BLL correlate with altered DNA methylation at 564 loci in their children’s neonatal blood. Our results suggest that Pb exposure during pregnancy affects the DNA methylation status of the fetal germ cells, which leads to altered DNA methylation in grandchildren’s neonatal dried blood spots. This is the first demonstration that an environmental exposure in pregnant mothers can have an epigenetic effect on the DNA methylation pattern in the grandchildren. For the study, we selected 35 dried blood spots (DBS) collected from mother-infant pairs from Health Fairs ran in three Detroit communities, because they have a high prevalence (8-11%) of high BLL in children. The sample set consisted of 25 male children and 18 female children. We also collected the neonatal DBS and mother neonatal DBS for these mother-infant pairs from the Michigan Neonatal Biobank. Then we measured a blood lead levels in dried blood spots using using atomic absorbtion spectrophotometry. Finally we measured the DNA methylation levels using human methylation 450K array from Illumina. Then we normalized the data for technical biases and tried to infer the the locus specific DNA methylation changes due to Pb exposure which was carried over from the grandmothers to the grandchildren by the Pb –exposed fetal germ cells of the mother using statistical model proposed by Sofer et al, 2012.
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the French Ligue Nationale Contre le Cancer (<a href=""ttp://cit.ligue-cancer.net/"" target=""_blank"">http://cit.ligue-cancer.net</a>). Selecting patients with metastatic clear-cell renal cell carcinoma (m-ccRCC) who might benefit from treatment with targeted tyrosine kinase inhibitors (TKIs) is a challenge. Our aim was to identify molecular markers associated with outcome in m-ccRCC patients treated with sunitinib."
Project description:The biological underpinnings of post-traumatic stress disorder (PTSD) have not been fully elucidated. Previous work suggests that alterations in the immune system are characteristic of the disorder. Identifying the biological mechanisms by which such alterations occur could provide fundamental insights into the etiology and treatment of PTSD. Here we identify specific epigenetic profiles underlying immune system changes associated with PTSD. Using blood samples (n=100) obtained from an ongoing, prospective epidemiologic study in Detroit, the Detroit Neighborhood Health Study (DNHS), we applied methylation microarrays to assay CpG sites from over 14,000 genes among 23 PTSD-affected and 77 PTSD-unaffected individuals. We show that immune system functions are significantly overrepresented among the annotations associated with genes uniquely unmethylated among those with PTSD. We further demonstrate that genes whose methylation levels are significantly and negatively correlated with traumatic burden show a similar strong signal of immune function among the PTSD-affected. The observed epigenetic variability in immune function by PTSD is corroborated using an independent biological marker of immune response to infection, cytomegalovirus—a typically latent herpesvirus whose activity was significantly higher among those with PTSD. These results provide the first report of peripheral epigenomic and CMV profiles associated with mental illness and suggest a new biological model of PTSD etiology in which an externally experienced traumatic event induces downstream alterations in immune function by reducing methylation levels of immune-related genes. Bisulfite conversion of whole blood-derived DNA samples was performed using the EZ-96 DNA methylation kit from Zymo Research. One microgram (μg) of each sample (including controls) was subjected to bisulfite conversion following manufacturer’s recommended protocol. 100 samples were analyzed of which 23 are PTSD affected and 77 are PTSD-unaffected. There were four technical replicates comprised of duplicate samples of two randomly selected individuals from the n=100 and duplicate samples of the control human methylated and unmethylated DNA.
Project description:The aim of this study was to identify new candidate genes that are differentially methylated in squamous cell carcinoma compared to the DNA samples from cervical intraepithelial neoplasia grade 3 (CIN3) and normal cervical scrapes. The Illumina Infinium Human Methylation 450 K BeadChip method identifies genome-wide DNA methylation changes in CpG islands, CpG shores and shelves. In this study 20 normal cervical samples (HPV negative), 18 samples with CIN3 lesions (HPV positive) and 6 cervical cancer tissues (HPV positive) were included.
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Anaplastic oligodendrogliomas (AOs) are rare primary brain tumors which are generally incurable with few treatment targets identified. Most oligodendrogliomas have chromosome 1p/19q co-deletion and IDH mutation. We analyzed 51 AOs by whole-exome and/or transcriptome sequencing identifying previously reported frequent somatic mutations in CIC and FUBP1 genes. We also identified recurrent mutations in TCF12 (11% of IDHmut-codel) which encodes basic helix-loop-helix (bHLFH) transcription factor 12 which is an oligodendrocyte-related transcription factor in IDHmut-codel tumors. Strikingly, the somatic mutations (encoding E548R and R602M substitutions) have not been reported previously in cancer but are identical to germline mutations causing craniosynostosis. Incorporating TCGA data on 43 AO tumors also implicates functional mutation of SMARCA4, NOTCH1, NOTCH2, SETD2, RBPJ and ARID1A/1B. These data are compatible with the combined deregulation of metabolism, chromatin organization/remodeling and Notch-pathway genes in AO oncogenesis. Our analysis provides further insights into the unique and shared pathways driving AO and new targets for therapeutic intervention.
Project description:∼40,000 HNF6 binding sites were identified in mouse liver chromatin, including several thousand sites showing significant differences in level of HNF6 binding between male and female mouse liver. These sex-biased HNF6 binding sites showed strong enrichment for sex-biased DNase hypersensitive sites and for proximity to genes showing local sex-biased chromatin marks and a corresponding sex-biased expression. ~90% of genome-wide CUX2 binding sites identified previously in female mouse liver (Conforto TL, Zhang Y, Sherman J, Waxman DJ., Mol Cell Biol. 2012;32(22):4611-4627) were also bound by HNF6, giving evidence for genome-wide competition between HNF6 and CUX2 for chromatin binding in female mouse liver. These HNF6/CUX2 common binding sites were enriched for genomic regions more accessible in male than in female mouse liver chromatin, and showed strongest enrichment for male-biased genes, suggesting HNF6 displacement by CUX2 as a mechanism to explain the observed CUX2 repression of male-biased genes in female liver. However, HNF6 binding was sex-independent at a majority of its binding sites, and peak regions of HNF6 binding were frequently associated with co-binding by multiple other liver transcription factors, consistent with HNF6 playing a global regulatory role in both male and female liver. Livers were excised from individual male and female mice, cross-linked and sonicated, then used to identify HNF6 binding sites by ChIP-Seq using antibody specific to HNF6 (sc-13050; Santa Cruz Biotechnology, Inc).