Project description:Environmental factors during perinatal development influence developmental plasticity and disease susceptibility via alterations to the epigenome. Developmental exposure to the endocrine active compound, bisphenol A (BPA), has previously been associated with altered methylation at candidate gene loci. Here, we undertake the first genome-wide characterization of DNA methylation profiles in the liver of murine offspring perinatally exposed to multiple doses of BPA through the maternal diet. Using a tiered focusing approach, our strategy proceeds from unbiased broad DNA methylation analysis using methylation-based next generation sequencing technology to in-depth quantitative site-specific CpG methylation determination using the Sequenom EpiTYPER MassARRAY platform to profile liver DNA methylation patterns in offspring maternally exposed to BPA during gestation and lactation to doses ranging from 0 BPA/kg (Ctr), 50 M-BM-5g BPA/kg (UG), or 50 mg BPA/kg (MG) diet (N=4 per group). Genome-wide analyses indicate non-monotonic effects of DNA methylation patterns following perinatal exposure to BPA, corroborating previous studies using multiple doses of BPA with non-monotonic outcomes. We observed enrichment of regions of altered methylation (RAMs) within CpG island (CGI) shores, but little evidence of RAM enrichment in CGIs. An analysis of promoter regions identified several hundred novel BPA-associated methylation events, and methylation alterations in the Myh7b and Slc22a12 gene promoters were validated. Using the Comparative Toxicogenomics Database, a number of candidate genes that have previously been associated with BPA-related gene expression changes were identified, and gene set enrichment testing identified epigenetically dysregulated pathways involved in metabolism and stimulus response. In this study, non-monotonic dose dependent alterations in DNA methylation among BPA-exposed mouse liver samples and their relevant pathways were identified and validated. The comprehensive methylome map presented here provides candidate loci underlying the role of early BPA exposure and later in life health and disease status. For this study, liver DNA from a subset of a/a wild-type animals was analyzed for full methylome characteristics: 1) standard diet (Ctr, n = 4 offspring; 2 male and 2 female); 2) 50 M-BM-5g BPA/kg diet (UG, n = 4 offspring; 2 male and 2 female); 3) 50 mg BPA/kg diet (MG, n = 4 offspring; 1 male and 3 female).
Project description:Environmental factors during perinatal development influence developmental plasticity and disease susceptibility via alterations to the epigenome. Developmental exposure to the endocrine active compound, bisphenol A (BPA), has previously been associated with altered methylation at candidate gene loci. Here, we undertake the first genome-wide characterization of DNA methylation profiles in the liver of murine offspring perinatally exposed to multiple doses of BPA through the maternal diet. Using a tiered focusing approach, our strategy proceeds from unbiased broad DNA methylation analysis using methylation-based next generation sequencing technology to in-depth quantitative site-specific CpG methylation determination using the Sequenom EpiTYPER MassARRAY platform to profile liver DNA methylation patterns in offspring maternally exposed to BPA during gestation and lactation to doses ranging from 0 BPA/kg (Ctr), 50 µg BPA/kg (UG), or 50 mg BPA/kg (MG) diet (N=4 per group). Genome-wide analyses indicate non-monotonic effects of DNA methylation patterns following perinatal exposure to BPA, corroborating previous studies using multiple doses of BPA with non-monotonic outcomes. We observed enrichment of regions of altered methylation (RAMs) within CpG island (CGI) shores, but little evidence of RAM enrichment in CGIs. An analysis of promoter regions identified several hundred novel BPA-associated methylation events, and methylation alterations in the Myh7b and Slc22a12 gene promoters were validated. Using the Comparative Toxicogenomics Database, a number of candidate genes that have previously been associated with BPA-related gene expression changes were identified, and gene set enrichment testing identified epigenetically dysregulated pathways involved in metabolism and stimulus response. In this study, non-monotonic dose dependent alterations in DNA methylation among BPA-exposed mouse liver samples and their relevant pathways were identified and validated. The comprehensive methylome map presented here provides candidate loci underlying the role of early BPA exposure and later in life health and disease status.
Project description:Bisphenol-A is a widespread endocrine disruptor chemical. In utero or perinatal exposure to bisphenol-A (BPA), leads to impaired glucose metabolism during adulthood. To investigate the consequences of the exposure to bisphenol-A during development in pancreatic beta-cell growth We used microarrays to determine gene expression changes resulting from exposure to bisphenol-A during pregnancy in pancreatic islets of the male offspring at postnatal day 30.
Project description:Bisphenol A (BPA), an endocrine-disrupting chemical (EDC), is a well-known, ubiquitous estrogenic chemical. To investigate the effects of fetal exposure to low-dose BPA on the development of the prostate, we first examined the alterations of in situ sex steroid hormonal environment in the mouse urogenital sinus (UGS). Next, to investigate the BPA-specific gene alterations related to increases of the E2 levels and aromatase activity, we performed comprehensive gene expression analysis using Affymetrix GeneChip in the BPA-treated or DES-treated male UGS at embryonic day 17th and postnatal day 1st.
Project description:Developmental lead (Pb) exposure results in persistent cognitive/behavioral impairments as well as an elevated risk for developing a variety of diseases in later life. Environmental exposures during development can result in a variety of epigenetic changes, including alterations in DNA methylation, that can influence gene expression patterns and affect the function and development of the nervous system. The present promoter-based methylation microarray profiling study explored the extent to which developmental Pb exposure may modify the methylome of a brain region, hippocampus, known to be sensitive to the effects of Pb exposure. Male and female Long Evans rats were exposed to 0 ppm, 150 ppm, 375 ppm, or 750 ppm Pb through perinatal exposures (gestation through lactation), early postnatal exposures (birth through weaning), or long-term postnatal exposures (birth through postnatal day 55). Results showed a significant contribution of sex to the hippocampal methylome and effects of Pb exposure level, with non-linear dose response effects on methylation. Surprisingly, the developmental period of exposure contributed only a small amount of variance to the overall data and gene ontology (GO) analysis revealed the largest number of overrepresented GO terms in the groups with the lowest level of exposure. The highest number of significant differentially methylated regions was found in females exposed to Pb at the lowest exposure level. Our data reinforce the significant effect that low level Pb exposure may have on gene-specific DNA methylation patterns in brain and that this occurs in a sex-dependent manner. NimbleGen Rat CpG Island plus RefSeq Promoter 720k array
Project description:Plasticizers with estrogenic activity, such as bisphenol A (BPA), have been reported to have potential adverse health effects in humans, especially in fetal and infant stages. Due to mounting evidence and public pressure BPA is being phased out by the plastics manufacturing industry and is being replaced by other bisphenol variants in “BPA-free” products. We have compared estrogenic activity of 7 bisphenol analogues (BPA; bisphenol S, BPS; bisphenol F, BPF; bisphenol AP, BPAP; bisphenol AF, BPAF; bisphenol Z, BPZ; bisphenol B, BPB) in human breast cancer cell lines. We used microarrays to detail the alterations in gene expression profiles associated with MCF-7 cell line exposure to bisphenol A analogues
Project description:Bisphenol A (BPA) is used in the plastic industry as the monomer of polycarbonates and epoxy resins. Heat and changes in pH conditions lead to its leakage from the plastics in which it is incorporated. This largely contributes to the widespread exposure of the general population to this environmental contaminant. The exposure levels in humans are likely below the Tolerable Daily Intake (TDI: 50 µg/kg/day) and well below the No Observable Adverse Effect Level (NOAEL: 5000 µg/kg/day) defined from reprotoxicity studies. However, several studies suggest that BPA could induce deleterious effects specifically at low, environmentally relevant, doses. BPA has been described as an endocrine disruptor with estrogenic activity. Recently, it has been shown that BPA exposure has an impact on metabolic functions including stimulation of adipogenesis and of insulin production by the pancreas. Here, we investigated the effects of oral exposure to low (TDI) and high (NOAEL) doses of BPA on mouse liver transcriptome. Liver gene expression was measured from CD-1 mice (6 mice/group) exposed for 28 days to bisphenol A at doses 0 (controls), 50 (TDI or low dose) or 5000 µg/kg/day (NOAEL or high dose) via food contamination.
Project description:Multiple sclerosis (MS) is a complex disease influenced by genetic and environmental contributing factors. Endocrine disrupting compounds (EDCs) such as bisphenol A (BPA) affect gene expression and hormone-regulated systems throughout the body. We investigated the effects of BPA on Theiler’s-virus induced demyelination (TVID), a mouse model of MS. Perinatal BPA exposure, combined with viral infection, resulted in a decreased level of viral antibodies, accelerated the onset of TVID symptoms, increased inflammation in both the spinal cord and digestive tract, and amplified immune-related gene expression changes induced by viral infection. These results demonstrate the effect of BPA on the trajectory of TVID, and illustrate how multiple factors collectively influence autoimmune disease. For microarray: 7 samples