title: Atrazine enhances progesterone production through activation of multiple signaling pathways in FSH-stimulated rat granulosa cells: evidence for premature luteinization.
abstract: Premature luteinization is a possible cause of infertility in women. It is currently unknown whether environmental chemicals can induce changes associated with premature luteinization. Using rat granulosa cells (GC) in vitro, we demonstrated that exposure to atrazine (ATR), a widely used herbicide, causes GC phenotype that resembles that of human premature luteinization. At the end of the 48-h stimulation with FSH, ATR-exposed GC showed (1) higher levels of progesterone, (2) overexpression of luteal markers (Star and Cyp11a1), and (3) an increase in progesterone:estradiol ratio above 1. Mechanistic experiments were conducted to understand the signaling events engaged by ATR that lead to this phenotype. Western blot analysis revealed prolonged phosphorylation of protein kinase B (AKT) and cAMP response element-binding protein (CREB) in ATR- and FSH-exposed GC. An increased level of ERK1/2-dependent transcriptional factor CCATT/enhancer-binding protein beta (CEBPB) was observed after 4 h of ATR exposure. Inhibitors of PI3K (wortmannin) and MEK (U0126) prevented ATR-induced rise in progesterone level and expression of luteal markers in FSH-stimulated GC. Atrazine intensified AKT and CEBPB signaling and caused Star overexpression in forskolin-stimulated GC but not in epidermal growth factor (EGF)-stimulated GC. In the presence of rolipram, a specific inhibitor of phosphodiesterase 4 (PDE4), ATR was not able to further elevate AKT phosphorylation, CEBPB protein level, and Star mRNA in FSH-stimulated GC, suggesting that ATR inhibits PDE4. Overall, this study showed that ATR acts as a FSH sensitizer leading to enhanced cAMP, AKT, and CEBPB signaling and progesterone biosynthesis, which promotes premature luteinization phenotype in GC.
authors.affiliation: Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Kristina
authors.initials: K
authors.lastname: Pogrmic-Majkic
authors.affiliation: Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Dragana
authors.initials: D
authors.lastname: Samardzija
authors.affiliation: Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Fa
authors.affiliation: Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Hrubik
authors.affiliation: Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Branka
authors.initials: B
authors.lastname: Glisic
authors.affiliation: Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia.
authors.forename: Sonja
authors.initials: S
authors.lastname: Kaisarevic
authors.affiliation: Molecular and Reproductive Toxicology Unit, Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia nebojsa.andric@dbe.uns.ac.rs.
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Andric
mesh_terms: D000818:Animals; D001280:Atrazine / Q000494:pharmacology*; D002478:Cells, Cultured; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects* / Q000378:metabolism; D006540:Herbicides / Q000494:pharmacology*; D034461:Luteinization / Q000187:drug effects* / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors
chemical_list: D006540:Herbicides; D011374:Progesterone; D005640:Follicle Stimulating Hormone; D001280:Atrazine
keywords: AKT; CEBPB; PDE4; atrazine; granulosa cells; premature luteinization; progesterone/progesterone receptor