title: Involvement of ERK1/2 signaling pathway in atrazine action on FSH-stimulated LHR and CYP19A1 expression in rat granulosa cells.
abstract: Worldwide used herbicide atrazine is linked to reproductive dysfunction in females. In this study, we investigated the effects and the mechanism of atrazine action in the ovary using a primary culture of immature granulosa cells. In granulosa cells, follicle-stimulating hormone (FSH) activates both cyclic adenosine monophosphate (cAMP) and extracellular-regulated kinase 1/2 (ERK1/2) cascades, with cAMP pathway being more important for luteinizing hormone receptor (LHR) and aromatase (CYP19A1) mRNA expression. We report that 48h after atrazine exposure the FSH-stimulated LHR and CYP19A1 mRNA expression and estradiol synthesis were decreased, with LHR mRNA being more sensitive to atrazine than CYP19A1 mRNA. Inadequate acquisition of LHR in the FSH-stimulated and atrazine-exposed granulosa cells renders human chorionic gonadotropin (hCG) ineffective to stimulate amphiregulin (Areg), epiregulin (Ereg), and progesterone receptor (Pgr) mRNA expression, suggesting anti-ovulatory effect of atrazine. To dissect the signaling cascade involved in atrazine action in granulosa cells, we used U0126, a pharmacological inhibitor of ERK1/2. U0126 prevents atrazine-induced decrease in LHR and CYP19A1 mRNA levels and estradiol production in the FSH-stimulated granulosa cells. ERK1/2 inactivation restores the ability of hCG to induce expression of the ovulatory genes in atrazine-exposed granulosa cells. Cell-based ELISA assay revealed that atrazine does not change the FSH-stimulated ERK1/2 phosphorylation in granulosa cells. The results from this study reveal that atrazine does not affect but requires ERK1/2 phosphorylation to cause decrease in the FSH-induced LHR and CYP19A1 mRNA levels and estradiol production in immature granulosa cells, thus compromising ovulation and female fertility.
authors.affiliation: Laboratory for Ecotoxicology, Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Fa
authors.forename: Kristina
authors.initials: K
authors.lastname: Pogrmic-Majkic
authors.forename: Dragana
authors.initials: D
authors.lastname: Samardzija
authors.forename: Branka
authors.initials: B
authors.lastname: Glisic
authors.forename: Sonja
authors.initials: S
authors.lastname: Kaisarevic
authors.forename: Radmila
authors.initials: R
authors.lastname: Kovacevic
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Andric
mesh_terms: D000818:Animals; D001141:Aromatase / Q000096:biosynthesis*; D001280:Atrazine / Q000494:pharmacology*; D002070:Butadienes / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D006540:Herbicides / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D009570:Nitriles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011974:Receptors, LH / Q000096:biosynthesis*
chemical_list: D002070:Butadienes; D004791:Enzyme Inhibitors; D006540:Herbicides; D009570:Nitriles; D011974:Receptors, LH; C113580:U 0126; D005640:Follicle Stimulating Hormone; D001141:Aromatase; C561410:CYP19A1 protein, human; D001280:Atrazine