Cis-bifenthrin inhibits cortisol and aldosterone biosynthesis in human adrenocortical H295R cells via cAMP signaling cascade

Cis-bifenthrin (cis-BF) is a common-used pyrethroid insecticide frequently detected in environmental and biological matrices. Mounting evidence highlights the endocrine disrupting effects of cis-BF due to anti-estrogenic or anti-androgenic activity. However, little is known about the exposure effects of cis-BF on adrenal cortex function. In this study, effects of cis-BF on biosynthesis of adrenal steroids, as well as the potential mechanisms were investigated in human adrenocortical carcinoma (H295R) cells. Cis-BF decreased basal production levels of cortisol and aldosterone, as well as cAMP-induced production of cortisol. Both he basal and cAMP-stimulated transcriptional levels of several steroidogenic genes were significantly down-regulated by cis-BF. As an important rate-limiting enzyme in steroidogenesis, the protein level of StAR was prohibited by cis-BF on both basal and cAMP-induced conditions. Intracellular level of cAMP was significantly reduced by cis-BF. Overall, these data suggest that cis-BF may inhibit the biosynthesis of cortisol and aldosterone via disrupting cAMP signaling cascade.

Zingiber officinale ethanolic extract attenuates oxidative stress, steroidogenic gene expression alterations, and testicular histopathology induced by sodium arsenite in male rats

Arsenic (As) indelibly exists in the environment and may reach to a food chain. Flavors and herbs are recognized sources of natural antioxidants that play imperative against harmful chemical pollutants. Ginger is utilized around the world as a zesty condiment. This study assessed the ability of ginger extract (GE) as a protector to improve regenerative disabilities initiated by sodium arsenate in reproductive functions in male rats. Thirty-two Sprague-Dawley male rats weighted 240 ± 10 g were arbitrarily relegated into four experimental groups (n = 8): the control group; the GE-treated group received at 100 mg/kg BW; the As-treated group received sodium arsenite at 10 mg/kg BW; the fourth group received sodium arsenite additionally GE at mentioned doses for 4 weeks. Phytochemical results of GE revealed that GE had good antioxidative characteristics and high content of total flavonoid, tannins, alkaloids, and total phenolic components. Simultaneously, treatment of GE showed protection against oxidative stress induced by As and restoration of the serum cholesterol, testosterone, LH, and sperm parameter to normal levels. GE significantly improved the antioxidant activities (GSH, SOD, and CAT) as well as H2O2 and MDA in rats received concurrently the GE and As compared with control group. Moreover, the expression of genes controlling the cholesterol transportation and testosterone synthesis (SR-B1, StAR, CYP11A1, 3b-HSD, 17b-HSD, and CYP17a) as well as LHR showed a meaningful improvement in rats treated by GE plus As compared with their expression in the As-treated group. Besides, GE treatment exhibited significant recovered testis histopathological alterations, reduced the arsenic content in testes, and improved the sperm parameters.

BPA's transgenerational disturbance to transcription of ovarian steroidogenic genes in rare minnow Gobiocypris rarus via DNA and histone methylation

As a well-known estrogenic endocrine disruptor, bisphenol A (BPA) is of utmost concern since it is reported with harmful effects on animal reproduction. However, the adverse effects on progeny after parental BPA exposure are largely unknown in fishes. To investigate the epigenetic effects of BPA on progeny gonadal development, parental rare minnow (Gobiocypris rarus) were exposed to BPA (15 μg L^-1) for two months, then were purged in clean water for one, two or three months, respectively. From the second month, parents were mated once a month and the offspring were reared to 5 months old. Results showed that parental BPA exposure inhibited the ovary development of the offspring by reducing the number of mature oocytes while the transcripts of steroidogenic genes (cyp11a1, cyp17a1, cyp19a1a and star) were significantly affected. And the negative effects of parental BPA exposure on the offspring were reversible. The DNA methylation and histone trimethylation levels (H3K9me3 and H3K27me3) together with the expression of dnmts (dnmt1, dnmt5 and dnmt7) and histone methyltransferase genes (setdb1, setdb2 and ezh2) were significantly altered in the ovaries of the 5-month old offsprings. BPA interfered the expression of steroidogenic genes by altering histone recruitment in star (H3K4me3 and H3K9me3), in cyp11a1 and cyp17a1 (H3K9me3 and H3K27me3), as well as in cyp19a1a (H3K4me3, H3K9me3 and H3K27me3). In addition, altering of DNA methylation at CpG site caused by BPA exposure involved in the regulation of star, cyp17a1 and cyp19a1a expression. These results suggest that BPA transgenerationally imposes detriment to reproduction and the epigenetic changes in DNA methylation and histone trimethylation might account for steroidogenic genes expression.

Increasing telomerase enhanced steroidogenic genes expression and steroid hormones production in rat and human granulosa cells and in mouse ovary

Telomerase, a ribonucleoprotein responsible for telomere re-elongation, is important for male and female fertility. Several factors, including the steroid hormone estrogen, regulate the expression of Telomerase Reverse Transcriptase (TERT), which one of its non-canonical functions is gene expression regulation. The steroidogenesis process is regulated principally by transcription of genes encoding steroidogenic enzymes, but it is not clear if TERT non-canonical functions affect the expression of steroidogenic genes. Here we investigated this new notion by increasing TERT expression and activity in granulosa cells (GCs) derived from rat and from women that underwent in vitro fertilization (IVF) procedures and in vivo in mouse ovary. We show that gonadotropin enhanced the expression of TERT in rat GCs. Overexpression of human- TERT enhanced the expression of steroidogenesis genes in gonadotropin-stimulated rat GCs. Moreover, treatment with TERT increasing compounds (AGS) alone enhanced the expression of the steroidogenic genes in both rat and human GCs and in vivo in mouse ovary, while telomerase inhibitor reduced their expression. Treatment with AGS compounds, together with gonadotropin stimulation, additively increased steroidogenic gene expression. Enhancing TERT expression and activity increased the level of progesterone in mouse blood and in the medium of rat GCs and estrogen in women derived pre-ovulatory luteinized GCs. These data suggest that increasing TERT in GCs by pharmaceutical compounds enhanced steroidogenesis and the production of steroid hormones that are essential processes in human and animal reproduction. These data also suggest a novel possible strategy for the enhancement of the production of steroid hormones.

Partial ameliorative effect of Moringa leaf ethanolic extract on the reproductive toxicity and the expression of steroidogenic genes induced by subchronic cadmium in male rats

The impact of Moringa oleifera leaf ethanol extract (MOLEE) was assessed on the expression of the steroidogenic genes (steroidogenic acute regulatory protein (StAR) and cytochrome P450c17 subfamily a (CYP17a) and luteinizing hormone receptor (LHR) gene) as well as on the cadmium chloride (CdCl₂)-induced reproductive toxicity for 56 days in male rats. Four groups were used: control, Moringa-treated (MOLEE), CdCl₂-treated, and CdCl₂ + MOLEE groups. The reproductive toxicity of CdCl₂ was confirmed; it caused a significant decrease in the accessory sex organ weights, testosterone level, testicular GST level, elevated MDA level (lipid peroxidation indicator), and histopathological alterations in seminiferous tubules, prostate, seminal vesicles, and epididymis as well as sperm characteristics. It also induced downregulation in the expression of StAR and CYP17a genes without change in the expression LHR gene. Eleven active compounds were detected in the GC-MS analysis of MOLEE; six of them have antioxidant properties, and five new compounds presented variable activities. MOLEE alone induced a stimulatory effect on the expression of steroidogenic and LHR genes. It restored the weight of reproductive organs to the control level; however, the recovery in sperm count, motility, abnormalities, percentage of alive sperm, testosterone, and MDA level are still comparable with the control level. Similar findings were also reported at the histological structure of the testes, epididymis, and accessory sex glands. Complete recovery of the GST enzyme activity was observed. Additionally, a restoration in the expression level of the steroidogenic genes was also reported. Our results indicated that the concurrent administration of MOLEE with CdCl₂ can partially mitigate its harmful effects on male fertility.

Evidence for expression and functionality of FSH and LH/hCG receptors in human endometrium

PURPOSE

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) mediate intracellular functions by binding their specific protein G-coupled gonadotrophin receptor, respectively FSH receptor (FSHR) and LH/choriogonadotrophin receptor (LHCGR). Whereas the expression of FSHR and LHCGR in mammals was considered gonad-specific and cell-specific, studies identified gonadotrophin receptors in human female extragonadal reproductive tissues. This study aims to demonstrate that gonadotrophin receptors are expressed in endometrium and mediates intracellular functions.

METHODS

Collected endometria (n = 12) from healthy patients (mean age of 36 ± 6) were primary cultured for 24 h. The presence of gonadotrophin receptors was evaluated by RT-PCR followed by the sequencing of the resulted amplicons and by immunohistochemistry in original samples. Endometrial primary cultures were treated with increasing concentration (range 0-100 ng/ml) of either recombinant human LH (rhLH) or recombinant human FSH (rhFSH). Endometria controls had gonadotrophin replaced by the same volume of the culture medium. In gonadotrophin-treated samples, it was evaluated the intracellular cyclic adenosine monophosphate (cAMP) content by enzymatic immunoassay and the expression of steroidogenic genes by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR).

RESULTS

The sequencing of the RT-PCR amplicons confirmed the presence of both gonadotrophin receptors and immunohistochemistry localized them on the membrane of endometrial glands cells throughout the glandular epithelium. The gonadotrophin-receptor complex was able to increase the intracellular cAMP in a dose-response and time-course manner and to induce steroidogenic genes expression.

CONCLUSION

This study demonstrates that both gonadotrophin receptors are expressed along the glandular epithelium of endometria and they mediate the effects of gonadotrophins on intracellular functions.

Anti-estrogenic effect of semicarbazide in female zebrafish (Danio rerio) and its potential mechanisms

Semicarbazide (SMC), a member of the hydrazine family, has various toxic effects and has been detected in organisms, aquatic environments, and food. SMC exposure inhibited the transcription of hepatic vitellogenin and estrogen receptors in female zebrafish (Danio rerio), suggesting that it had anti-estrogenic properties. In order to elucidate the mechanisms underlying these, we exposed female zebrafish to SMC and used enzyme-linked immunosorbent assays to examine plasma 17β-estradiol (E2) and testosterone (T) levels. Gonad histology was analyzed and the mRNA expression of genes involved in the reproductive axis, the gamma-aminobutyric acid (GABA) shunt, and leptin was quantified by real-time PCR. Zebrafish were exposed to 1, 10, 100, or 1000μg/L SMC in a semi-static system for 96hours or 28 days. Plasma E2 levels were significantly decreased and ovarian maturation was inhibited by SMC, suggesting that its anti-estrogenic effect was exerted by reducing endogenous E2 levels. This was likely due to the SMC-mediated inhibition of cytochrome P450 (CYP) 19A mRNA levels, because this enzyme catalyzes the conversion of T to E2 in the gonads. In addition, down-regulation of the mRNA expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase, steroidogenic acute regulatory protein, CYP17, and 17beta-hydroxysteroid dehydrogenase was observed; this was predicted to reduce T concentrations and further contribute to the reduced E2 levels. SMC-induced changes in the expression of these steroidogenic genes correlated with decreased transcription of gonadotropic hormones (follicle-stimulating hormone and luteinizing hormone) and significantly elevated leptin expression. Furthermore, SMC also altered expression of the key enzyme in gamma-aminobutyric acid (GABA) synthesis, GABA receptors, and salmon gonadotropin-releasing hormone, thus affecting gonadotropin expression. Overall, SMC acted at multiple sites related to reproduction to reduce plasma E2 levels, consequently exerting an anti-estrogenic effect in female zebrafish. These effects were observed at environmentally relevant concentrations and highlight the importance of controlling SMC contamination.

Melatonin replacement restores the circadian behavior in adult rat Leydig cells after pinealectomy

Melatonin actions on oscillators in reproductive organs are poorly understood. Here we analyzed melatonin effects on rhythmic expression of clock and steroidogenesis-related genes in adult rat Leydig cells (LCs). The effect of melatonin was tested both in vivo using pinealectomized and melatonin-substituted rats and in vitro on isolated LCs. Data revealed 24-h-rhythmic expression of clock genes (Bmal1, Per1,2,3, Rev-erba,b, Rorb), steroidogenic genes (Star, Cyp11a1, Cyp17a1), and genes of steroidogenic regulators (positive-Nur77, negative-Arr19). Pinealectomy increased 24-h-oscillations of serum testosterone and LC's cAMP levels, expression of Insl3, Per1, Star/StAR, Hsd3b1/2, Nur77, decreased Arr19 and canceled Per2 oscillatory expression pattern. At hypothalamic-pituitary level, pinealectomy increased mesor of Gnrh, Lhb and rhythm robustness of Mntr1a expression. All parameters disturbed were restored by melatonin-replacement. In vitro studies did not confirm direct melatonin effects on neither clock nor steroidogenic genes. Accordingly, melatonin influence 24-h-rhythmic LC-function likely through hypothalamic-pituitary axis and consequently cAMP-signaling in LCs.

Gonadal development and transcript profiling of steroidogenic enzymes in response to 17α-methyltestosterone in the rare minnow Gobiocypris rarus

It is well known that natural and anthropogenic chemicals interfere with the hormonal system of vertebrate and invertebrate organisms. How these chemicals regulate gonadal steroidogenesis remains to be determined. The main objective of this study was to evaluate the effects of 17α-methyltestosterone (MT), a synthetic model androgen, on gene expression profiles of six key steroidogenic genes in adult rare minnow. The full-length cDNA encoding 11β-hydroxysteroid dehydrogenase-2 (11β-HSD2) was firstly isolated and characterized by RT-PCR and RACE methods. The gonadal transcript changes of StAR, cyp11a1, 3β-HSD, cyp17a1, 11β-HSD2 and cyp19a1a in 6-month adult Gobiocypris rarus exposed to MT and 17α-ethinylestradiol (EE2) for 7, 14 and 21 days were detected by qRT-PCR. To make an effort to connect the transcriptional changes of steroidogenic enzymes with effects on higher levels of biological organization and on VTG, one remarkable sensitive target of steroids, body and gonad weights, histology of gonads, and hepatic vtg mRNA level were measured. MT caused varying degree of abnormalities in ovaries and testes. The hepatic vtg mRNA level was highly inhibited in females and slightly altered in males by MT. Transcripts of several steroidogenic genes including StAR, cyp17a1, and cyp11a1 showed high responsiveness to MT exposure in G. rarus. The gene expression profiles of these steroidogenic genes in MT-treated groups were much distinct with the EE2-treated group.

Biotransformation of dihydroisosteviol and the effects of transformed products on steroidogenic gene expressions

The biotransformation of dihydroisosteviol with Absidia pseudocylindrospora ATCC 24169, Streptomyces griseus ATCC 10137, Mucor recurvatus MR36, and Aspergillus niger BCRC 31130 yielded 15 metabolites, eight of which were previously unknown. Structures of metabolites were established by 2D NMR techniques and HRMS data, two of which were further corroborated by chemical means, and another via single-crystal X-ray diffraction analysis. Subsequently, two steroidogenic cell lines (Y-1 mouse adrenal tumor and MA-10 mouse Leydig tumor cells) were used in a reverse transcription-PCR analysis to assess the effects of all compounds on steroidogenic gene expressions using forskolin as a positive control. The tested gene expressions included steroidogenic factor-1 (SF-1), steroidogenic acute regulatory protein (StAR), and cytochrome P450 side-chain cleavage (P450scc) enzyme. Gene expression profiles showed that ten of the tested compounds effectively suppressed P450SCC mRNA expression in both Y-1 and MA-10 cells. Several induced SF-1 gene expression and two enhanced StAR gene expression in Y-1 cells. By contrast, in MA-10 cells, one compound effectively suppressed StAR mRNA expression, whereas for others effectively suppressed SF-1 gene expression. The results suggest that analogs of dihydroisosteviol can be potential modulators to alter steroidogenic gene expressions and subsequent enzyme activities.