Inhibitory effects of epidermal growth factor on progesterone production of ovarian granulosa cells in Tsaiya duck (Anas platyrhynchos var. domestica)

Role of kisspeptin on cell proliferation and steroidogenesis in luteal cells in vitro and in vivo

BACKGROUND

Kisspeptin (KISS1) and kisspeptin receptor (KISS1R) are essential gatekeepers of the reproductive system. The functions of KISS1 and KISS1R in corpus luteal cells remain ambiguous. The objective was to observe normal physiologic functions of corpus luteal cells in vivo and clarify the functions of KISS1 in vitro.

METHODS

We conducted an in vivo observation of cellular patterns as well as the levels of steroidogenic enzymes and KISS1/KISS1R in corpus luteal cells obtained from female crossbred Taiwan native goats in the estrous cycle; the observation was performed using hematoxylin and eosin and immunohistochemistry staining. Subsequently, we used kisspeptin-10 (Kp-10) to stimulate temperature sensitive-caprine luteal cell line (ts-CLC-D) cells to investigate the progesterone (P4) levels, steroidogenic messenger RNA (mRNA)/protein levels, cell survival rate, intracellular Ca2+ concentration, and cell proliferation-related mRNA/protein levels in the mitogen-activated protein kinase pathway in vitro by applying immunofluorescence staining, Western blotting, 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assay, and real-time polymerase chain reaction.

RESULTS

We observed the presence of proteins and mRNAs for STAR, CYP11A1, HSD3B, KISS1, and KISS1R in the corpus luteal cells from goats in vivo. In vitro, the addition of Kp-10 reduced the P4 levels (p < 0.01) and increased cell proliferation (p < 0.05) of the ts-CLC-D cells. Furthermore, we found that the levels of proteins and mRNA for STAR, CYP11A1, and HSD3B decreased significantly when Kp-10 was added (p < 0.05). However, adding Kp-10 did not affect the mRNA levels for PLCG2, DAG1, PRKCA, KRAS, RAF1, MAP2K1, MAP2K2, MAPK3, MAPK1, and MAPK14.

CONCLUSION

We determined that KISS1 could affect the P4 levels, steroidogenesis, and cell proliferation in luteal cells. However, further research is required to clarify how KISS1 regulates proliferation and steroid production in luteal cells.

Curcumin downregulates 8-br-cAMP-induced steroidogenesis in mouse Leydig cells by suppressing the expression of Cyp11a1 and StAR independently of the PKA-CREB pathway

Although curcumin was widely applied as a functional food for different diseases, it was found to reduce serum testosterone level and fertility in male animals by unknown molecular mechanisms. Here in our study, we investigated the possible mechanisms of curcumin-suppressed testosterone production in Leydig cells. Our enzyme immunoassay results showed that curcumin cell-autonomously suppressed ovine luteinizing hormone-stimulated testosterone production in primary Leydig cells and 8-bromo-cyclic adenosine monophosphate (8-br-cAMP)-induced progesterone production in MA-10 cells. Furthermore, our real-time PCR, Western blot, and 22R-OHC/pregnenolone supplementing experiment data demonstrated that curcumin suppressed 8-br-cAMP-induced steroidogenesis in Leydig cells by inhibiting the expression of StAR and Cyp11a1. Interestingly, our Western blot data showed that although curcumin suppressed PKA activity, it did not alter the 8-br-cAMP-induced phosphorylation of CREB. On the contrary, the real-time PCR results showed that curcumin suppressed 8-br-cAMP-induced expression of Nr5a1 and Fos, which are crucial for cAMP-stimulated StAR and Cyp11a1 expression in Leydig cells. Collectively, our data demonstrated that curcumin may suppress cAMP-induced steroidogenesis in mouse Leydig cells by down-regulating Nr5a1/Fos-controlled StAR and Cyp11a1 expression independently of the PKA-CREB signaling pathway.

Molecular cloning and expression patterns of the cholesterol side chain cleavage enzyme (CYP11A1) gene during the reproductive cycle in goose (Anas cygnoides)

Background

CYP11A1, a gene belonging to the family 11 of cytochrome P450, encodes a crucial steroidogenic enzyme that catalyzes the initial step in the production of all classes of steroids. Many studies show that CYP11A1 plays a role in ovary function. However, the role of CYP11A1 in goose reproductive cycle remains largely unknown.

Results

In this study, full-length CYP11A1 cDNA of Zhedong goose was obtained using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The cDNA consisted of a 96-base pair (bp) 5′untranslated region (UTR), a 179-bp 3′UTR and a 1509-bp open reading frame. The open reading frame encodes a putative 503 amino acid protein that shares high homology with CYP11A1 of other birds. The amino acid sequence possesses conserved domains of the P450 superfamily, which include the steroid-binding domain and the heme-binding region. Real-time quantitative polymerase chain reaction (qPCR) analysis revealed CYP11A1 mRNA was expressed ubiquitously in every Zhedong goose tissue analyzed, including the heart, liver, glandular stomach, lung, spleen, kidney, intestinum tenue, intestinum crassum, cerebrum, cerebellum, muscle, oviduct, pituitary, hypothalamus and ovary.. The relatively low levels of CYP11A1 mRNA were detected in pituitary, ovary and oviduct tissues at ovulation when compared with levels at oviposition. Interestingly, higher expression was observed in ovary and oviduct tissues during brooding. Lastly, higher mRNA expression of Yangzhou geese was detected during the ovulation period than that of Zhedong geese.

Conclusions

Our findings reveal the sequence characterization and expression patterns of the CYP11A1 gene during the goose reproductive cycle, which may provides correlative evidence that CYP11A1 expression is important in reproduction activity.

Astaxanthin protects steroidogenesis from hydrogen peroxide-induced oxidative stress in mouse Leydig cells

Androgens, especially testosterone produced in Leydig cells, play an essential role in development of the male reproductive phenotype and fertility. However, testicular oxidative stress may cause a decline in testosterone production. Many antioxidants have been used as reactive oxygen species (ROS) scavengers to eliminate oxidative stress to protect steroidogenesis. Astaxanthin (AST), a natural extract from algae and plants ubiquitous in the marine environment, has been shown to have antioxidant activity in many previous studies. In this study, we treated primary mouse Leydig cells or MA-10 cells with hydrogen peroxide (H₂O₂) to cause oxidative stress. Testosterone and progesterone production was suppressed and the expression of the mature (30 kDa) form of StAR protein was down-regulated in MA-10 cells by H₂O₂ and cAMP co-treatment. However, progesterone production and expression of mature StAR protein were restored in MA-10 cells by a one-hour pretreatment with AST. AST also reduced ROS levels in cells so that they were lower than the levels in untreated controls. These results provide additional evidence of the potential health benefits of AST as a potential food additive to ease oxidative stress.

Molecular Mechanism of Isocupressic Acid Supresses MA-10 Cell Steroidogenesis

Consumption of ponderosa pine needles causes late-term abortions in cattle and is a serious poisonous plant problem in foothill and mountain rangelands. Isocupressic acid (IA) is the component of pine needles responsible for the abortifacient effect, its abortifacient effect may be due to inhibition of steroidogenesis. To investigate the more detail molecular mechanism, we used MA-10 cell, which is wild used to investigate molecular mechanism of steroidogenesis, to characterize the molecular mechanisms underlying the actions of IA in more detail. In this report, we focus on the function of IA on important steroidogenic genes, including steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage (P450scc), and 3β-hydroxysteroid dehydrogenase (3β-HSD). We found that IA does not affect enzyme activities of these genes but inhibits transcription of P450scc and translation of StAR and P450scc through attenuating cAMP-PKA signaling. Thus, steroid productions of cells were suppressed.