title: Modulation of aryl hydrocarbon receptor target genes in circulating lymphocytes from dairy cows bred in a dioxin-like PCB contaminated area.
abstract: Animal productions (i.e. fish, eggs, milk and dairy products) represent the major source of exposure to dioxins, furans, and dioxin-like (DL) polychlorobiphenyls for humans. The negative effects of these highly toxic and persistent pollutants are mediated by the activation of the aryl hydrocarbon receptor (AHR) that elicits the transcriptional induction of several genes, including those involved in xenobiotic metabolism. Previously we demonstrated the presence and functioning of the AHR signaling pathway in primary cultures of bovine blood lymphocytes. The aim of the present study was to investigate by real time PCR the expression and the inducibility of selected target genes (i.e. AHR, AHR nuclear translocator (ARNT), AHR repressor, CYP1A1 and CYP1B1) in uncultured cells from dairy cows naturally exposed to DL-compounds. The study was carried out on two groups of animals bred in a highly polluted area and characterized by a different degree of contamination, as assessed by bulk milk TEQ values, and a control group reared in an industry free area. Bovine lymphocytes expressed only AHR, ARNT and CYP1B1 genes to a detectable level; moreover, only CYP1B1 expression appeared to be correlated to TEQ values, being higher in the most contaminated group, and decreasing along with animal decontamination. Finally, lymphocytes from exposed cows displayed a lower inducibility of both CYP1A1 and CYP1B1 after the in vitro treatment with a specific AHR ligand. In conclusion, our results indicate that DL-compound contaminated cows may display significant changes in AHR-target gene expression of circulating lymphocytes.
authors: Department of Animal Pathology, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco, Italy. flavia.girolami@unito.it
authors: Flavia
authors: F
authors: Girolami
authors: Veronica
authors: V
authors: Spalenza
authors: Monica
authors: M
authors: Carletti
authors: Paola
authors: P
authors: Sacchi
authors: Roberto
authors: R
authors: Rasero
authors: Carlo
authors: C
authors: Nebbia
mesh_terms: D000821:Animal Feed; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator / Q000235:genetics; D002417:Cattle / Q000097:blood*; D002478:Cells, Cultured; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D065633:Cytochrome P-450 CYP1B1; D003612:Dairying; D004147:Dioxins / Q000032:analysis / Q000633:toxicity*; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis / Q000633:toxicity*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D007558:Italy; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D008892:Milk / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000633:toxicity*; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
chemical_list: D004147:Dioxins; D004785:Environmental Pollutants; D018336:Receptors, Aryl Hydrocarbon; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D011078:Polychlorinated Biphenyls; D001189:Aryl Hydrocarbon Hydroxylases; C585496:CYP1B1 protein, human; D019363:Cytochrome P-450 CYP1A1; D065633:Cytochrome P-450 CYP1B1