Project description:Recently it was discovered that the perfluorooctane sulfonate (PFOS) detected in wildlife, such as fish-eating birds, had a greater proportion of linear PFOS (L-PFOS) than the manufactured technical product (T-PFOS), which contains linear and branched isomers. This suggests toxicological studies based on T-PFOS data may inaccurately assess exposure risk to wildlife. To determine if PFOS effects were influenced by isomer content we compared the transcriptional profiles of cultured chicken embryonic hepatocytes (CEH) exposed to either L-PFOS or T-PFOS using Agilent microarrays. At equal concentrations (10 μM), T-PFOS altered the expression of more transcripts (340, >1.5 fold change, p<0.05) compared to L-PFOS (130 transcripts). Higher concentrations of L-PFOS (40 μM) were also less transcriptionally disruptive (217 transcripts) than T-PFOS at 10 μM. Functional analysis showed that L-PFOS and T-PFOS affected genes involved in lipid metabolism, hepatic system development and cellular growth and proliferation. Pathway and interactome analysis suggested that genes may be affected through the RXR receptor, oxidative stress response, TP53 signaling, MYC signaling, Wnt/β-catenin signaling and PPARγ and SREBP receptors. In all functional categories and pathways examined, the response elicited by T-PFOS was greater than L-PFOS. These data show that T-PFOS elicits a greater transcriptional response in CEH than L-PFOS alone and demonstrates the importance of considering the isomer-specific toxicological properties of PFOS when assessing exposure risk. Reference Design. Reference = pool of equal parts of all control and treated samples. Control groups and 5 treatment groups. Control samples were CEH exposed DMSO only (vehicle solvent). Treatments were: CEH exposed to 10 uM L-PFOS, 40 uM L-PFOS, 10 uM T-PFOS, 0.03 nM TCDD and 1 nM TCDD.
Project description:This series was used for two studies: Study 1: Recently it was discovered that the perfluorooctane sulfonate (PFOS) detected in wildlife, such as fish-eating birds, had a greater proportion of linear PFOS (L-PFOS) than the manufactured technical product (T-PFOS), which contains linear and branched isomers. This suggests toxicological studies based on T-PFOS data may inaccurately assess exposure risk to wildlife. To determine if PFOS effects were influenced by isomer content we compared the transcriptional profiles of cultured chicken embryonic hepatocytes (CEH) exposed to either L-PFOS or T-PFOS using Agilent microarrays. At equal concentrations (10 ?M), T-PFOS altered the expression of more transcripts (340, >1.5 fold change, p<0.05) compared to L-PFOS (130 transcripts). Higher concentrations of L-PFOS (40 ?M) were also less transcriptionally disruptive (217 transcripts) than T-PFOS at 10 ?M. Functional analysis showed that L-PFOS and T-PFOS affected genes involved in lipid metabolism, hepatic system development and cellular growth and proliferation. Pathway and interactome analysis suggested that genes may be affected through the RXR receptor, oxidative stress response, TP53 signaling, MYC signaling, Wnt/?-catenin signaling and PPAR? and SREBP receptors. In all functional categories and pathways examined, the response elicited by T-PFOS was greater than L-PFOS. These data show that T-PFOS elicits a greater transcriptional response in CEH than L-PFOS alone and demonstrates the importance of considering the isomer-specific toxicological properties of PFOS when assessing exposure risk. Study 2: In many bird populations, concentrations of perfluoroundanoic acid (PFUdA) are second only to perfluorooctane sulfonate (PFOS) among perfluoroalkyl compounds. Here, we used microarrays to characterize the transcriptional response of cultured chicken embryonic hepatocytes (CEH) to PFUdA and compared it to the response induced by PFOS. At non-cytotoxic doses, PFUdA (1 or 10 ?M) disrupted the expression of more genes (854) than PFOS (447, at 10 or 40 ?M) in CEH. Using functional, pathway and interactome analysis we identified several potentially important modes-of-action (MoAs) for PFUdA and some associated key events, including the suppression of the acute-phase response (APR) through peroxisome proliferator activated receptor activation. We then measured the expression of five APR genes, fibrinogen alpha (fga), fibrinogen gamma (fgg), thrombin (f2), plasminogen (plg), and protein C (proC), in the liver of chicken embryos exposed in ovo to PFUdA. The expression of fga, f2, and proC were down-regulated in embryo livers (100 or 1000 ng/g, p<0.1) as predicted from microarray analysis, whereas fibrinogen gamma (fgg) was up-regulated and plg was not significantly affected. Our results demonstrate PFUdA is more transcriptionally disruptive than PFOS in CEH. Additionally, we identified APR suppression as a potentially important and environmentally relevant MoA. These findings suggest in ovo exposure of birds to PFUdA could lead to post-hatch developmental deficiencies, such as impaired immune response.
Project description:Relative expression levels of mRNAs in chicken cecal epithelia experimentally infected with Eimeria tenella were measured at 4.5 days post-infection. Two weeks old chickens were uninfected (negative control) or were orally inoculated with sporulated oocysts of Eimeria tenella. Cecal epithelia samples were collected from >12 birds in infected or uninfected group at 4.5 d following infections, in which samples from 4 birds were pooled together to form a total 3 biological replicates in each group. Parasite merozoites were also collected from four infected chickens at 5 d after infections. Uninfected control samples, merozoites and infection group samples were selected for RNA extraction and hybridization on Affymetrix microarrays. We used Affymetrix GeneChip chicken genome arrays to detail the chicken cecal epithelia gene expression in the control and E. tenella-infected birds.
Project description:The existence of conventional dendritic cells (cDCs) has not yet been demonstrated outside mammals. In this paper, we identified bona fide cDCs in chicken spleen. Comparative profiling of global and of immune response gene expression, morphology, and T cell activation properties show that cDCs and macrophages (MPs) exist as distinct mononuclear phagocytes in chicken, resembling their human and mouse cell counterparts. Using computational analysis, core gene expression signatures for cDCs, MPs, T and B cells across chicken, human and mouse were established, which will facilitate the identification of these subsets in other vertebrates. Overall this study, by extending the newly uncovered cDC and MP paradigm to chicken, suggests that the generation of these two phagocyte lineages occurred before the reptile to mammal and bird transition in evolution. It opens avenues for the design of new vaccines and neutraceuticals that are mandatory for the sustained supply of poultry products in the expanding human population.
Project description:We report the transcriptomes of 10 different chicken (Gallus gallus) cell/tissue types. The goal of this project was to determine similarities and differences between different cell/tissue types, with respect to protein coding genes, lncRNA, isoform counts, and differential gene expression. We provide raw data and bigWig files for UCSC visualization. The findings described here will be useful towards a complete annotation of chicken tissue and cellular transcriptomes.
Project description:Humans and ecological species have been found to have detectable body burdens of a number of perfluorinated alkyl acids (PFAA) including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). In mouse and rat liver these compounds elicit transcriptional and phenotypic effects similar to peroxisome proliferator chemicals (PPC) that work through the nuclear receptor peroxisome proliferator activated receptor alpha (PPARalpha). Recent studies indicate that along with PPARalpha other nuclear receptors are required for transcriptional changes in the mouse liver after PFOA exposure including the constitutive activated receptor (CAR) and pregnane X receptor (PXR) that regulate xenobiotic metabolizing enzymes (XME). To determine the potential role of CAR/PXR in mediating effects of PFAAs in rat liver, we performed a meta-analysis of transcript profiles from published studies in which rats were exposed to PFOA or PFOS. We compared the profiles to those produced by exposure to prototypical activators of CAR (Phenobarbital (PB)), PXR (pregnenolone 16 alpha-carbonitrile (PCN)), or PPARalpha (WY-14,643 (WY)). As expected, PFOA and PFOS elicited transcript profile signatures that included many known PPARalpha target genes. Numerous XME genes were also altered by PFOA and PFOS but not WY. These genes exhibited expression changes shared with PB or PCN. Reexamination of the transcript profiles from the livers of chicken or fish exposed to PFAAs indicated that PPARalpha, CAR, and PXR orthologs were not activated. Our results indicate that PFAAs under these experimental conditions activate PPARalpha, CAR, and PXR in rats but not chicken and fish. Lastly, we discuss evidence that human populations with greater CAR expression have lower body burdens of PFAAs. Keywords: gene expression/microarray