ABSTRACT
The increasing incidence of reproductive anomalies, described as testicular dysgenesis syndrome, is thought to be related to the exposure of the population to chemicals in the environment. Bisphenol A (BPA) and di(2-ethylhexyl)phthalate (DEHP), which have hormonal and antihormonal activity, have attracted public attention due to their presence in consumer products. The present study investigated the effects of BPA and DEHP on reproductive development. Timed-pregnant female rats were exposed to BPA and DEHP by gavage from gestational days 12 to 21. Results showed that prenatal exposures to test chemicals exerted variable effects on steroidogenic factor 1 and GATA binding protein 4 protein expression and increased (P < .05) sex-determining region Y-box 9 and antimüllerian hormone protein in the infantile rat testis compared with levels in the control unexposed animals. Pituitary LHß and FSHß subunit protein expression was increased (P < .05) in BPA- and DEHP-exposed prepubertal male rats but were decreased (P < .05) in adult animals relative to control. Exposure to both BPA and DEHP in utero inhibited (P < .05) global DNA hydroxymethylation in the adult testis in association with altered DNA methyltransferase protein expression. Together the present data suggest that altered developmental programming in the testes associated with chemical exposures are related to the disruption of sexual differentiation events and DNA methylation patterns. The chemical-induced effects impact the development of steroidogenic capacity in the adult testis.
Subject(s)
Benzhydryl Compounds/pharmacology , Diethylhexyl Phthalate/pharmacology , Environmental Pollutants/pharmacology , Estrogens, Non-Steroidal/pharmacology , Phenols/pharmacology , Plasticizers/pharmacology , Sex Differentiation/drug effects , Testis/drug effects , Animals , Anti-Mullerian Hormone/metabolism , DNA Methylation/drug effects , DNA Modification Methylases/drug effects , DNA Modification Methylases/metabolism , Endocrine Disruptors/pharmacology , Female , Follicle Stimulating Hormone, beta Subunit/drug effects , Follicle Stimulating Hormone, beta Subunit/metabolism , GATA4 Transcription Factor/drug effects , GATA4 Transcription Factor/metabolism , Gonadal Dysgenesis , Luteinizing Hormone, beta Subunit/drug effects , Luteinizing Hormone, beta Subunit/metabolism , Male , Pituitary Gland/drug effects , Pituitary Gland/metabolism , Pregnancy , Prenatal Exposure Delayed Effects , Rats , Sex-Determining Region Y Protein/drug effects , Sex-Determining Region Y Protein/metabolism , Steroidogenic Factor 1/drug effects , Steroidogenic Factor 1/metabolism , Testicular Diseases , Testis/metabolismABSTRACT
Ferredoxin 1 (FDX1; adrenodoxin) is an iron-sulfur protein that is involved in various metabolic processes, including steroid hormone synthesis in mammalian tissues. We investigated the transcriptional regulation of FDX1 in ovarian granulosa cells. Previously, we reported that the NR5A family, including steroidogenic factor-1 (SF-1) and liver receptor homolog-1 could induce differentiation of human mesenchymal stem cells (hMSCs) into steroidogenic cells. A ChIP assay showed that SF-1 could bind to the FDX1 promoter in differentiated hMSCs. Luciferase reporter assays showed that transcription of FDX1 was synergistically activated by the NR5A family and 8Br-cAMP treatment through two SF-1 binding sites and a CRE-like sequence in a human ovarian granulosa cell line, KGN. Knockdown of FDX1 attenuated progesterone production in KGN cells. These results indicate transcription of FDX1 is regulated by the NR5A family and cAMP signaling, and participates in steroid hormone production in ovarian granulosa cells.
Subject(s)
Ferredoxins/genetics , Granulosa Cells/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Steroidogenic Factor 1/metabolism , 8-Bromo Cyclic Adenosine Monophosphate/pharmacology , Adrenodoxin/genetics , Animals , Cell Differentiation , Cell Line, Tumor , Cyclic AMP/metabolism , DNA-Binding Proteins/metabolism , Female , Ferredoxins/biosynthesis , Gene Expression Regulation , HeLa Cells , Humans , Mesenchymal Stem Cells/metabolism , Progesterone/biosynthesis , Promoter Regions, Genetic , Protein Binding , RNA Interference , RNA, Small Interfering , Rats , Rats, Wistar , Signal Transduction , Steroidogenic Factor 1/drug effects , Transcription, GeneticABSTRACT
The mechanisms by which TBT produces modulations of the endocrine systems are not fully described. In this study, juvenile salmon were force-fed diet containing TBT (0: solvent control, 0.1, 1 and 10 mg/kg fish) for 72 h. Subsequently, fish exposed to solvent control and 10 mg/kg TBT were exposed to waterborne concentration of the adenyl cyclase stimulator forskolin (200 µg/L) for 2 and 4 h. Tissue and blood were sampled from individual fish (n=6). Gene expression patterns of CYP11ß, steroidogenic factor-1 (SF-1), and glucocorticoid receptor (GlucR) were determined by qPCR. TBT generally decreased mRNA levels of CYP11ß, GlucR and SF-1, compared to the solvent control and these effects were differentially modulated by the presence of forskolin. This study suggests that TBT may exert broader endocrine disrupting effects through possible modulation of cAMP/PKA second messenger systems.
Subject(s)
Colforsin/pharmacology , Salmon/physiology , Trialkyltin Compounds/toxicity , Water Pollutants, Chemical/toxicity , Animals , Cyclic AMP/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Cytochrome P-450 Enzyme System/drug effects , Cytochrome P-450 Enzyme System/metabolism , Endocrine Disruptors/toxicity , RNA, Messenger/drug effects , RNA, Messenger/metabolism , Receptors, Glucocorticoid/drug effects , Receptors, Glucocorticoid/metabolism , Second Messenger Systems , Steroidogenic Factor 1/drug effects , Steroidogenic Factor 1/metabolismABSTRACT
Both fibroblast growth factor 2 (FGF2) and luteinizing hormone (LH) have been reported to regulate androgen production in Leydig cells in progenitor Leydig cells. The objective of the present study is to examine the regulation of androgen production in rat immature Leydig cells (ILCs). ILCs were isolated from 35-day-old rat testes and cultured in DMEM/F12 medium with LH (1 ng/ml) or FGF2 (10 ng/ml). 5alpha-Androstane-3alpha, 17beta-diol (3alpha-DIOL), the primary androgen in ILCs, and testosterone (T) were measured by Radioimmuno assay. The results showed the LH stimulated androgen production in ILCs, and FGF2 did not. However, FGF2 decreased the LH-stimulated androgen production. Real-time PCR and enzyme assay showed that FGF2 decreased levels of several steroidogenic enzymes, inhibited the expressions of steroidogenic acute regulatory (StAR) protein and steroidogenic factor 1 (Nr5a1) in LH-stimulated ILCs. FGF2-mediated inhibition of Nr5a1gene expression may be the mechanism through which FGF2 inhibits LH-stimulated androgen production.