Identification and characterization of long non-coding RNAs in porcine granulosa cells exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

Background: Long non-coding RNAs(lncRNAs) may regulate gene expression in numerous biological processes including cellular response to xenobiotics.The exposure of living organisms to 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD),a persistent environmental contaminant,results in reproductive defects in many species including pigs.The aims of the study were to identify and characterize lncRNAs in porcine granulosa cells as well as to examine the effects of TCDD on the lncRNA expression profile in the cells.Results: One thousand six hundred sixty-six lncRNAs were identified and characterized in porcine granulosa cells.The identified lncRNAs were found to be shorter than mRNAs.In addition,the number of exons was lower in lncRNAs than in m RNAs and their exons were longer.TCDD affected the expression of 22 lncRNAs(differentially expressed lncRNAs [DELs]; log2 fold change ≥ 1,P-adjusted < 0.05) in the examined cells.Potential functions of DELs were indirectly predicted via searching their target cis-and trans-regulated protein-coding genes.The coexpression analysis revealed that DELs may influence the expression of numerous genes,including those involved in cellular response to xenobiotics,dioxin metabolism,endoplasmic reticulum stress and cell proliferation.Aryl hydrocarbon receptor(AhR) and cytochrome P450 1 A1(CYP1 A1) were found among the trans-regulated genes.Conclusions: These findings indicate that the identified lncRNAs may constitute a part of the regulatory mechanism of TCDD action in granulosa cells.To our knowledge,this is the first study describing lncRNAs in porcine granulosa cells as well as TCDD effects on the lncRNA expression profile.These results may trigger new research directions leading to better understanding of molecular processes induced by xenobiotics in the ovary.

Flutamide-induced alterations in transcriptional profiling of neonatal porcine ovaries

Background: Androgens are involved in the regulation of ovarian development during fetal/neonatal life.Environmental chemicals displaying anti-androgenic activities may affect multiple signal transduction pathways by blocking endogenous androgen action.The aim of the current study was to examine effects of the anti-androgen flutamide on the expression of coding transcripts and long non-coding RNAs(lncRNAs) in neonatal porcine ovaries.By employing RNA-Seq technology we aimed to extend our understanding of the role of androgens in neonatal folliculogenesis and examine the impact of the anti-androgen flutamide on ovarian function.Method: Piglets were subcutaneously injected with flutamide(50 mg/kg BW) or corn oil(controls) between postnatal days 1 and 10(n = 3/group).Ovaries were excised from the 11-day-old piglets and total cellular RNAs were isolated and sequenced.Results: Flutamide-treated piglet ovaries showed 280 differentially expressed genes(DEGs;P-adjusted < 0.05 and log2 fold change ≥1.0) and 98 differentially expressed lncRNAs(DELs;P-adjusted < 0.05 and log2 FC ≥ 1.0).The DEGs were assigned to GO term,covering biological processes,molecular functions and cellular components,which linked the DEGs to functions associated with cellular transport,cell divisions and cytoskeleton.In addition,STRING software demonstrated strongest interactions between genes related to cell proliferation.Correlations between DEGs and DELs were also found,revealing that a majority of the genes targeted by the flutamide-affected lncRNAs were associated with intracellular transport and cell division.Conclusions: Our results suggest that neonatal exposure of pigs to flutamide alters the expression of genes involved in ovarian cell proliferation,ovarian steroidogenesis and oocyte fertilization,which in turn may affect female reproduction in adult life.

Leptin/leptin receptor system in the regulation of reproductive functions and stress response in the European beaver

The European beaver (Castor fiber L.) is the largest free-living rode nt in Eurasia. The prese nt work aimed to determi ne sex- and seas on-related cha nges in leptin receptor (Ob-R) expression in the hypothalamic-pituitary-gonadal/adrenal axes and uterus of beavers during breeding-(April), postbreeding-(July), and pre-breeding-(November) periods. The expression of Ob-R gene and protein was found in all analyzed tissues. The expression of Ob-R mRNA remained constant in the hypothalamus of both sexes during the analyzed stages. Sex- and season-related changes were found in the pituitary gland;the greatest level was observed in July in both sexes. The same expression pattern was noted in the testis, whereas in the ovary a lack of seasonal changes was found. In uterine tissues, the greatest expression occurred in November. The impact of season was also demonstrated in the adrenal cortex. In females, a higher Ob-R transcript level was noted in April, while in males, an increased mRNA abundanee was noted in November than July. Our study suggests that in the beaver, leptin acting via the Ob-R can be an important endocrine factor engaged in the regulation of reproductive functions and stress response.