Effects of Developmental Lead Exposure on the Hippocampal Transcriptome.
ABSTRACT: In this study we analyzed the effects of lead-exposure up hippocampal gene expression in males and females exposed to 0ppm, 250ppm and 750ppm lead during two different developmental periods, perinatal (in utero through to weaning at PND21) and postnatal (PND0-PND45). All tissue was taken at PND 55. We used affymetrix Rat Gene 1.0ST arrays to obtain global gene expression data from each animal, with a group size of 4 for all conditions (Total number of Arrays = 40) Gene expression was profiled in hippocampus at no lead exposure (0ppm), 250ppm and 750 ppm lead exposure level at peinatal and postnaltal developmental period.
Project description:In this study we analyzed the effects of lead-exposure up hippocampal gene expression in males and females exposed to 0ppm, 250ppm and 750ppm lead during two different developmental periods, perinatal (in utero through to weaning at PND21) and postnatal (PND0-PND45), across three strains (Fischer, Long Evans and Sprague Dawley). All tissue was taken at PND 55. We used affymetrix Rat Gene 1.0ST arrays to obtain global gene expression data from each animal, with a group size of 4 for all conditions (Total number of Arrays = 119) Gene expression was profiled in the hippocampus of rats at no lead exposure (0ppm), 250ppm and 750 ppm lead exposure levels during perinatal and postnatal developmental periods of both males and females of three strains of rat (Fischer, Long Evans and Sprague Dawley).
Project description:Lead exposure causes a variety of health effects, especially in children, that may include cognitive and behavioural problems. This study explores the mechanisms associated with this relationship by assessing alterations in gene expression of C57BL/6J pups treated with 50mg/kg lead compared to controls. In addition this study also analyzed brain gene expression differences in Metallothionein I and II (Mt-I and Mt-II) knockout mice treated with lead. Pups of three genotypes (C57BL/6J, Mt-KO with a C57BL/6J background and Heterozygote Mt-KO) were injected with lead acetate during synaptogenesis and weight-matched controls were injected with saline at the same time points. Whole brains were harvested and RNA extracted and pooled from 5 pups and hybridized to Mouse Genome 430 2.0 Arrays. In total 6 arrays were used, one for each genotype and treatment.
Project description:There is an emerging concern that particulate air pollution increases the risk of cranial nerve disease onset. Small nanoparticles, mainly derived from diesel exhaust particles reach the olfactory bulb by their nasal depositions. It has been reported that diesel exhaust inhalation causes inflammation of the olfactory bulb and other brain regions. However, these toxicological studies have not evaluated animal rearing environment. We hypothesized that rearing environment can change mice phenotypes and thus might alter toxicological study results. In this study, we exposed mice to diesel exhaust inhalation at 90 micro g/m3, 8 hours/day, for 28 consecutive days after rearing in a standard cage or environmental enrichment conditions. Microarray analysis found that expression levels of 112 genes were changed by diesel exhaust inhalation. Functional analysis using Gene Ontology revealed that the dysregulated genes were involved in inflammation and immune response. This result was supported by pathway analysis. Quantitative RT-PCR analysis confirmed 10 genes. Interestingly, background gene expression of the olfactory bulb of mice reared in a standard cage environment was changed by diesel exhaust inhalation, whereas there was no significant effect of diesel exhaust exposure on gene expression levels of mice reared with environmental enrichment. The results indicate for the first time that the effect of diesel exhaust exposure on gene expression of the olfactory bulb was influenced by rearing environment. Rearing environment, such as environmental enrichment, may be an important contributive factor to causation in evaluating still undefined toxic environmental substances such as diesel exhaust. RNA sample was taken from olfactory bulb of 56-day-old mouse received diesel exhaust (DE) inhalation at 90 micro g/m3, 8 hours/day, for 28 consecutive days, while control RNA was taken from mouse received clean air, after rearing in a standard cage or environmental enrichment conditions. Comparisons among groups were made by one-color method with normalized data from Cy3 channels for data analysis.
Project description:75 Diosophilia Roo lines, recominant inbred lines, were raised to adulthood either on conventional diet or diet supplemented with lead acetate. Whole flies were used for RNA extraction. RNA was run on Dros Genome 2 arrays. Each line also genotyped for 88 markers; Control food consisted of standard cornmeal, agar, sugar, yeast, and 250 microM NaAc (Ashburner 1989). Lead-contaminated food consisted of standard food plus 250 microM PbAc (lead exposure at this concentration has been shown to affect locomotion in adults (Hirsch et al. 2003)). Experiment Overall Design: 75 RI lines each line treated and untreated with lead acetate
Project description:Sexual selection involves mate preference behavior and is a critical determinant for natural selection and evolutionary biology. Previously an environmental compound (fungicide vinclozolin) was found to promote epigenetic transgenerational inheritance of modified mate selection characteristics in all progeny for three generations after exposure of a gestating female. The current study investigated gene networks involved in various regions of the brain that correlated with the mate preference behavior altered in F3-Vinclozolin lineage animals. Statistically significant correlations of differentially expressed gene clusters and modules were identified to associate with specific mate preference behaviors. This novel systems biology approach identified critical gene networks involved in mate preference behavior and demonstrated the ability of environmental factors to promote epigenetic transgenerational inheritance of this altered evolutionary biology determinant. Combined observations elucidate the potential molecular control of mate preference behavior and suggests environmental epigenetics can have a role in evolutionary biology. We used Affymetrix Rat Gene 1.0 ST microarrays to determine genes expressed differentially in F3 Vinclozolin lineage male or female rats' 6 brain areas - amygdala (Amy), hippocampus (Hipp), olfactory bulb (OlfB), cingulate cortex (CngCtx), entorhinal cortex (EnCtx), and preoptic area-anterior hypothalamus (POAH) - due to Vinclozolin treatments of their grand-grandmothers (F0). For each of 6 brain areas of male or female rats (female: amygdala (F-Amy), cingulate cortex (F-CngCTX), enterorhinal cortex (F-EnCTX), hippocampus (F-Hipp), olfactory bulbs (F-OlfB), and preoptic area-anterior hypothalamus (F-POAH); male: amygdala (M-Amy), cingulate cortex (M-CngCTX), enterorhinal cortex (M-EnCTX), hippocampus (M-Hipp), olfactory bulbs (M-OlfB), and preoptic area-anterior hypothalamus (M-POAH)), RNA samples from 2 treatment groups - F3 Control lineage (Con) or F3 Vinclozolin lineage (Vin) - were compared to each other. Each of treatment groups contained 4-6 biological replicas for each brain region. RNA for each replica was isolated from an individual animal in order to compare to individual animal mate preference behavior studied with the same rats before sacrifice. Totally, 132 RNA samples from 24 animals (6 male F3 Control, 6 male F3 Vinclozolin,6 female F3 Control, and 6 female F3 Vinclozolin) were isolated and studied.
Project description:Background: Prenatal alcohol exposure (PAE) is associated with alterations in numerous physiological systems, including the stress and immune systems. We have previously shown that PAE increases the course and severity of arthritis in an adjuvant-induced arthritis (AA) model. While the molecular mechanisms underlying these effects are not fully known, changes in neural gene expression are emerging as important factors in the etiology of PAE effects. As the prefrontal cortex (PFC) and hippocampus (HPC) play key roles in neuroimmune function, PAE-induced alterations to their transcriptome may underlie abnormal steady-state functions and responses to immune challenge. The current study examined brains from adult PAE and control females from our recent AA study to determine whether PAE causes long-term alterations in gene expression and whether these mediate the altered severity and course of arthritis in PAE females Methods: Adult females from PAE, pair-fed [PF], and ad libitum-fed control [C]) groups were injected with either saline or complete Freund’s adjuvant. Animals were terminated at the peak of inflammation or during resolution (days 16 and 39 post-injection, respectively); cohorts of saline-injected PAE, PF and C females were terminated in parallel. Gene expression was analyzed in the PFC and HPC using whole genome mRNA expression microarrays. Results: Significant changes in gene expression in both the PFC and HPC were found in PAE compared to controls in response to ethanol exposure alone (saline-injected females), including genes involved in neurodevelopment, apoptosis, and energy metabolism. Moreover, in response to inflammation (adjuvant-injected females), PAE animals showed unique expression patterns, while failing to exhibit the activation of genes and regulators involved in the immune response observed in control and pair-fed animals. Conclusions: These results support the hypothesis that PAE affects neuroimmune function at the level of gene expression, demonstrating long-term effects of PAE on the CNS response under steady-state conditions and following an inflammatory insult. Key words: prenatal alcohol exposure (PAE), ethanol, inflammation, arthritis, gene expression, rat. 192 samples, including 20 hybridization replicates
Project description:Pregnant rats (Long-Evans) were dosed perinatally with 0 or 6 mg/kg/day of Aroclor 1254 from gestation day 6 through postnatal day (PND) 21. Gene expression in cerebellum and hippocampus from PND7 and PND14 animals was analyzed with an emphasis on developmental aspects. Changes in gene expression (>= 1.5 fold) in control animals identified normal developmental changes. These basal levels of expression were compared to data from Aroclor 1254-treated animals to determine the impact of gestational PCB exposure on developmental parameters. The results indicate that the expression of a number of developmental genes related to cell cycle, synaptic function, cell maintenance, and neurogenesis is significantly altered from PND7 to PND14. Aroclor 1254 treatment appears to dampen the overall growth-related gene expression levels in both regions with the effect being more pronounced in the cerebellum. Functional analysis suggests that Aroclor 1254 delays maturation of the developing nervous system, with the consequences dependent on the ontological state of the brain area and the functional role of the individual gene. Experiment Overall Design: Pregnant rats (Long-Evans) were dosed perinatally with 0 or 6 mg/kg/day of Aroclor 1254 from gestation day 6 through postnatal day (PND) 21. Gene expression in cerebellum and hippocampus from PND7 and PND14 animals was analyzed with an emphasis on developmental aspects.
Project description:Morphogenesis of the mammary gland relies on the precise developmental control of morphological elements including TEBs, ducts and lobules. In the peripubertal mammary gland, rising levels of ovarian hormones control this development through a tightly controlled genetic program where specific sets of genes are up-regulated. We used microarrays to detail the program of gene expression underlying different classes of up-regulated genes during the peripubertal process after administration of endocrine disruptors during the fetal and neonatal development. Rat mammary glands were selected at two peripubertal periods (days 35 and 50), after administration of genistein and vinclozolin during the fetal and neonatal development, for RNA extraction and hybridization on Affymetrix microarrays.. We sought to obtain homogeneous populations of mammary gland for each treatment, and at each developmental stage, in order to increase the temporal and specific effect resolution of time course and endocrine disruption.
Project description:Thyroid hormones (THs) play a critical role in development and throughout adulthood. THs act through the thyroid receptor (TR), which binds to the TH response element (TRE) to regulate the expression of target genes. Although TH action has been studied for decades, surprisingly few TREs have been well validated and characterized. In this study we used chromatin immunoprecipitation followed by microarray analysis (ChIP-chip) to identify TR-binding sites in juvenile (postnatal day 15) mice liver. Microarray analysis revealed twelve TR-binding sites consistent between all analyzed samples. In silico analysis was carried out to search for moderately conserved classic TRE sequences within these novel binding regions, which led to the identification of six candidate TREs within three binding regions. Luciferase reporter assays confirmed the presence of a TRE in the promoter region of DEAD (Asp-Glu-Ala-Asp) box polypeptide 54 (Ddx54) and thyroid hormone responsive SPOT14 (Thrsp). The TR/retinoid X receptor (RXR) heterodimer and RXR homodiner were shown to bind the promoter region of Ddx54 and drive gene expression in the presence of 9-cis-retinoic acid (9cRA). The promoter region of Thrsp was shown to allow binding of the TR/RXR heterodimer, and both T3 and 9cRA were able to significantly increase luciferase activity. The RXR homodimer was also able to bind the response element in the promoter region of Thrsp and increase luciferase activity. Overall, ChIP-chip analysis revealed a relatively limited number of TR-binding sites in juvenile mouse liver despite previous studies showing that numerous genes can be affected by TH disruption at that developmental stage, suggesting that TH action may also be mediated through other intermediates. Collectively the results provide an important step towards characterizing TR-binding sites and identifying the underlying drivers of TR-gene regulation. Three samples were analyzed (total input and immunoprecipitated for each samples).