Effects of 5α-dihydrotestosterone and 17β-estradiol on the mouse ovarian follicle development and oocyte maturation

Effects of puerarin as a feed additive on the laying performance, egg quality, endocrine hormones, antioxidant capacity, and intestinal morphology of aged laying hens

The aim of this study was to investigate the effects of puerarin (Pue), a phytoestrogen, on the production performance, egg quality, endocrine hormones, antioxidant capacity, and intestinal morphology in aged laying hens. A total of 180 Hy-Line Brown hens aged 480 d were randomly divided into 4 groups (n = 45 per group) and fed 0, 200, 400, and 800 mg/kg of Pue (Con, L-Pue, M-Pue, and H-Pue, respectively) during a 42-d experiment. Compared with the Con treatment, supplementation with H-Pue improved laying performance and egg quality by significantly increasing egg production, average egg weight, albumen height, yolk weight, and Haugh unit (P < 0.05) while decreasing the feed conversion ratio (P < 0.05). A diet supplemented with H-Pue significantly decreasing serum total triglycerides, total cholesterol, and low-density lipoprotein cholesterol, alanine aminotransferase (P < 0.05), and significantly increasing serum levels of follicle-stimulating hormone, luteinizing hormone and progesterone (P < 0.05). Antioxidant activity was improved by significantly increasing the activity of total antioxidant capacity, glutathione peroxidase and catalase but decreasing malondialdehyde levels in serum, jejunum, and ileum (P < 0.05), and superoxide dismutase activity exhibited a significantly increase in the jejunum and ileum (P < 0.05). Villus height and the ratio of villus height to crypt depth (P < 0.05) were significantly increased in the jejunum and ileum. In the jejunal and ileal mucosa, the three treatment groups increased the mRNA expression levels of Claudin-1 and Claudin-2 compared with Con (P < 0.05), and no significant effect was observed on the expression of Occludin and ZO-1. The results showed that dietary supplementation with Pue could improve the laying performance, egg quality, antioxidant capacity, hormonal profile, and intestinal morphology of aged laying hens.

Testosterone Supplementation Promotes Estrogen Synthesis of Buffalo Cumulus Cells Surrounding In Vitro-Matured Oocytes

Cumulus cells (CCs) synthesize estrogens that are essential for follicular development. However, the effects of androgen on estrogen production in buffalo CCs remain unknown. In the present study, the impacts of testosterone on estrogen synthesis of buffalo CCs surrounding in vitro-matured oocytes were investigated. The results showed that testosterone supplementation improved both the expression levels of estrogen synthesis-related genes (CYP11A1, CYP19A1, and 17β-HSD) and the secretion levels of estradiol in buffalo CCs surrounding in vitro-matured oocytes. Furthermore, testosterone treatment enhanced the sensitivity of buffalo CCs surrounding in vitro-matured oocytes to follicle-stimulating hormone (FSH). This study indicated that testosterone supplementation promoted the estrogen synthesis of buffalo CCs surrounding in vitro-matured oocytes mainly through strengthening the responsiveness of CCs to FSH. The present study serves as a foundation of acquiring high-quality recipient oocytes for buffalo somatic cell nuclear transfer.

Reducing 3D Hydrogel Stiffness, Addition of Oestradiol in a Physiological Concentration and Increasing FSH Concentration Improve In Vitro Growth of Murine Preantral Follicles

This study aimed to optimise culture conditions for murine preantral follicles to improve their growth and survival. Preantral follicles (diameter 100-130 µm) were isolated from prepubertal NMRI mice and individually cultured within alginate beads for 12 days. Three conditions were evaluated: (1) follicle re-encapsulation on day 6 of culture-reducing alginate concentration (0.5% to 0.25% w/v), (2) the presence of oestradiol (E2), and (3) increased follicle-stimulating hormone (FSH) concentration in the culture medium (from 10 to 100 mIU/mL FSH). Follicle morphology and growth, as well as anti-Müllerian hormone (AMH) production, were evaluated. From day 8, re-embedded follicles had a larger average diameter compared to follicles without alginate re-encapsulation (0.5% and 0.25% groups, p < 0.05). Oestradiol (1 µM) had a significantly positive effect on the mean follicular diameter and antrum formation (p < 0.001). Moreover, follicles cultured with 100 mIU/mL FSH showed faster growth (p < 0.05) and significantly higher antrum formation (p < 0.05) compared to the low FSH group. Nevertheless, AMH production was not affected by any of the culture conditions. In conclusion, the growth and survival of mouse preantral follicles during a 12-day period were improved by altering the alginate concentration midways during culture and adding E2 and FSH to the culture medium.

The gestational age-specific difference in birthweight between singletons born after fresh and frozen embryo transfer: A cohort study

INTRODUCTION

Accumulating studies have suggested singletons born after frozen embryo transfer (FET) were higher than those born after fresh embryo transfer (Fre-ET). However, fewer studies had investigated the gestational age-specific between-group difference in birthweight. This study aimed to investigate the gestational week-specific difference in singleton birthweight after FET vs Fre-ET and explore potential factors that impact the difference.

MATERIAL AND METHODS

In this retrospective cohort study, a total of 25 863 singletons were included. Multivariable linear regression and logistic regression were used to evaluate the between-group differences in mean birthweight and the incidences of large for gestational age (LGA) and small for gestational age (SGA), respectively.

RESULTS

Multivariable regression analyses showed a statistically significant interaction between types of embryo transfer (ie FET vs Fre-ET) and the gestational week on mean birthweight (P < 0.001) and on the risks of large for gestational age (P = 0.001) and small for gestational age (P < 0.001). When stratified by gestational week, the differences in mean birthweight and the risks of LGA and SGA were only observed in singletons born at 37 gestational weeks or later. After adjusting for confounders, full-term but not preterm singletons born after FET had a higher birthweight (3497.58 ± 439.73 g vs 3445.67 ± 450.24 g; adjusted mean difference 58.35 g; 95% confidence interval [CI] 38.72-77.98 g), a higher risk of LGA (24.3% vs 21.1%; adjusted odds ratio [OR] 1.28, 95% CI 1.15-1.42) and a lower risk of SGA (3.1% vs 4.8%; adjusted OR 0.61, 95% CI 0.53-0.70) compared with those born after Fre-ET.

CONCLUSIONS

The differences in birthweight between FET and Fre-ET were observed in full-term singletons but not preterm singletons.

BMP6 Promotes the Secretion of 17 Beta-Estradiol and Progesterone in Goat Ovarian Granulosa Cells

The purpose of this study was to investigate the effects of BMP6 on the function of goat ovarian granulosa cells (GCs). The results showed that the exogenous addition of BMP6 did not affect the EdU-positive ratio of ovarian GCs and had no significant effect on the mRNA and protein expression levels of the proliferation-related gene PCNA (p > 0.05). Meanwhile, BMP6 had no significant effect on the cycle phase distribution of GCs but increased the mRNA expression of CDK4 (p < 0.05) and CCND1 (p < 0.01) and decreased the mRNA expression of CCNE1 (p < 0.01). Moreover, BMP6 had no significant effect on the apoptosis rate of GCs and did not affect the mRNA expression levels of apoptosis-related genes BAX, BCL2, and Caspase3 (p > 0.05). Importantly, BMP6 upregulated the secretion of 17 beta-estradiol (E2) and progesterone (P4) in ovarian GCs (p < 0.01). Further studies found that BMP6 inhibited the mRNA expression of 3β-HSD and steroid synthesis acute regulator (StAR) but significantly promoted the mRNA expression of the E2 synthesis rate-limiting enzyme CYP19A1 and the P4 synthesis rate-limiting enzyme CYP11A1 (p < 0.01). Taken together, these results showed that the exogenous addition of BMP6 did not affect the proliferation, cell cycle, and apoptosis of goat ovarian GCs but promoted the secretion of E2 and progesterone P4 in ovarian GCs by upregulating the mRNA expressions of CYP19A1 and CYP11A1.

Effects of Zinc Methionine Hydroxy Analog Chelate on Laying Performance, Serum Hormone Levels, and Expression of Reproductive Axis Related Genes in Aged Broiler Breeders

Inorganic zinc (Zn) supplements are commonly used in poultry feeds, but their low utilization results in the increase of Zn excretion. Thus, to provide a new perspective for the substitution of inorganic Zn, a novel Zn methionine hydroxy analog chelate (Zn-MHA) was studied in the present study to evaluate its effects on laying performance, serum hormone indexes and reproductive axis-related genes in broilers breeders. A total of 480 Hubbard breeders (56-week-old) were fed a basal diet (containing 27.81 mg Zn/kg) without Zn addition for 2 weeks, and then allocated to 4 groups with 6 replicates (each replicate consisting of 10 cages and 2 breeders per cage) for 10 weeks. Four treatment diets given to broiler breeders included the basal diet added with 25, 50, and 75 mg/kg of Zn-MHA and 100 mg/kg of Zn sulfate (ZnSO₄). The laying rate, egg weight and feed conversation ratio increased in the 75 mg/kg Zn-MHA group compared to the ZnSO₄ group. The eggshell thickness was not decreased with the addition of 50 mg/kg and 75 mg/kg Zn-MHA in the diet compared to the 100 mg/kg ZnSO₄ group. There was a significant improvement in the reproductive performance of breeders in the 75 mg/kg Zn-MHA group, including the fertility and 1-day-old offspring weight. Besides, serum sex hormone levels including FSH and P₄ increased significantly in 75 mg/kg Zn-MHA group. No significant effect on the ovarian weight or the number of follicles in broiler breeders was observed by supplementing Zn-MHA. Compared to the 100 mg/kg ZnSO₄ group, dietary supplementation with 75 mg/kg of Zn-MHA showed an up-regulation of the FSHR mRNA in the granular layer of follicles. However, dietary supplementation of Zn-MHA had no effects on mRNA expressions of the ovarian LHR and PRLR genes. These findings reinforce the suggestion that Zn-MHA (75 mg/kg) could replace ZnSO₄ (100 mg/kg) as a Zn supplement in diet of broiler breeders, which resulted in better laying and reproduction performances by regulating the expression levels of reproductive axis related genes and serum hormone levels.

Pathology of hyperandrogenemia in the oocyte of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common ovulatory disorder in the world and is associated with multiple adverse outcomes. The phenotype is widely varied, with several pathologies contributing to the spectrum of the disease including insulin resistance, obesity and hyperandrogenemia. Of these, the role of hyperandrogenemia and the mechanism by which it causes dysfunction remains poorly understood. Early studies have shown that androgens may affect the metabolic pathways of a cell, and this may pose hazards at the level of the mitochondria. As mitochondria are strictly maternally inherited, this would provide an exciting explanation not only to the pathophysiology of PCOS as a disease, but also to the inheritance pattern. This review seeks to summarize what is known about PCOS and associated adverse outcomes with focus on the role of hyperandrogenemia and specific emphasis on the oocyte.

The Association Between Serum Estradiol Levels on hCG Trigger Day and Live Birth Rates in Non-PCOS Patients: A Retrospective Cohort Study

OBJECTIVE

To retrospectively analyze the association of serum estradiol (E2) levels on human chorionic gonadotropin (hCG) trigger day and live birth rates (LBRs) in women undergoing fresh embryo transfer and not exhibiting polycystic ovary syndrome.

DESIGN

Retrospective cohort study.

METHODS

Analysis of 13,950 patients who had fresh embryo transfer between December 2013 and December 2019. The main outcome measurement was LBRs. Multivariable regression analysis was performed to investigate associations between E2 levels on the hCG trigger day and LBRs. Stratification analysis was performed to test for effect modification in subgroups. Furthermore, a two-piecewise linear regression model was established to find nonlinear relationships.

RESULTS

Multivariable regression analysis showed a significant association between serum E2 levels on the hCG trigger day and LBRs, adjusting for covariates [relative risk (RR) 1.027, 95% confidence interval (CI) 1.007, 1.049]. Stratification analysis showed that the LBRs were positively associated (RR 1.052, 95% CI 1.004, 1.102) with every 1 ng/ml increase of serum E2 on the hCG trigger day for the subgroup with low antral follicle counts on the trigger day. Specifically, a two-piecewise linear regression model showed that there was a positive association (RR 1.188, 95% CI 1.057, 1.334) between serum E2 and LBR for every increase of 1 ng/ml E2 when the concentration of serum E2 was lower than 2.1 ng/ml. However, there was no significant association (RR 1.002, 95% CI 0.971, 1.032) between E2 levels and LBRs when the concentration of E2 was higher than the 2.1ng/ml inflection point.

CONCLUSIONS

Serum E2 levels on the hCG trigger day were segmentally connected with LBRs.

Follicular fluid steroid and gonadotropic hormone levels and mitochondrial function from exosomes predict embryonic development

PURPOSE

Human follicular fluid (FF) is a complex biological fluid that contributes to the micro-environment of oocyte development. The aim of this study was to evaluate the role of steroid and gonadotropic hormones levels and mitochondrial function in embryo development during in vitro fertilization cycles.

METHODS

This was a cohort study of 138 women receiving IVF/ICSI, including 136 FF samples from 109 infertile women. FF steroid and gonadotropic hormones levels were tested by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassays. The mRNA expression levels of mitochondrial electron transport chain (ETC) complex genes from FF exosomes were detected by qPCR.

RESULTS

Analysis of these individual FF concentrations revealed that LH and FSH concentrations were higher in follicles in which the oocyte developed into a top quality (TQ) blastocyst (LH: 9.44 ± 2.32mIU/ml, FSH: 9.32 ± 1.01mIU/ml) than those in which there was a failure of fertilization (LH: 5.30 ± 0.84mIU/ml, FSH: 6.91 ± 0.62mIU/ml). In contrast, follicular cortisone concentrations were lower for oocytes that resulted in a TQ blastocyst (12.20 ± 0.82mIU/ml). The receiver operating characteristic analysis showed that FF LH and FSH levels predicted TQ blastocyst with excellent AUC value of 0.711 and 0.747. Mitochondrial ETC complex I and III mRNA levels were increased in the FF exosomes of TQ blastocyst. Correlation analysis showed that mRNA levels of ETC complex I was positively correlated with LH and FSH levels in FF.

CONCLUSION

The levels of FF steroid and gonadotropic hormones from single follicle can predetermine subsequent embryo development to some extent. Furthermore, impaired exosome mitochondrial dysfunction is a potiential event that causes hormone change in embryo development.

Hyperandrogenemia alters mitochondrial structure and function in the oocytes of obese mouse with polycystic ovary syndrome

Capsule

Hyperandrogenemia in an obese PCOS mouse model results in altered glucose/insulin metabolism and mitochondrial structure and function in the oocytes, in part explaining adverse outcomes and inheritance patterns seen in PCOS.

Objective

To study the oocyte quality by means of mitochondrial structure and function in a well-established classic PCOS mouse model.

Design

Animal study using an obese PCOS mouse model compared with control.

Setting

Animal research facility in a tertiary care university hospital setting.

Animals

C57/B6J mice.

Intervention

Three week old mice had subdermal implants of DHT controlled release pellet or placebo for 90 days.

Main Outcome Measures

The mouse model was validated by performing glucose tolerance test, HbA1c levels, body weight and estrous cycle analyses. Oocytes were subsequently isolated and were used to investigate mitochondrial membrane potential, oxidative stress, lipid peroxidation, ATP production, mtDNA copy number, transcript abundance, histology and electron microscopy.

Results

Results showed glucose intolerance and hyperinsulinemia along with dysregulated estrus cycle. Analysis of the oocytes demonstrated impaired inner mitochondrial membrane function, increased ATP production and mtDNA copy number, altered RNA transcript abundance and aberrant ovarian histology. Electron microscopy of the oocytes showed severely impaired mitochondrial ultrastructure.

Conclusion

The obese PCOS mouse model shows a decreased oocyte quality related to impaired mitochondrial function.

Neonatal androgenization in rats affects oocyte maturation

Androgens are relevant in order to achieve a normal growth and maturation of the follicle and oocyte, since both excess and absence of androgens may affect the correct ovarian function. The current study analyzes the impact of neonatal androgenization in the first ovulation and oocyte maturation in response to exogenous gonadotrophin stimulation. Neonatal rats were daily treated with testosterone, dihydrotestosterone, or vehicle during follicle assembly period (days 1 to 5). At juvenile period, rats were stimulated sequentially with PMSG and hCG. Ovulation, ovarian histology, hormonal milieu, morphological characteristics of meiotic spindle, and in vitro fertilization rate in oocytes were analyzed. Our data shows that oocytes from androgenized rats displayed a major proportion of aberrant spindles and altered meiotic advance that control animals. These alterations were accompanied with an increase in both fertilization rate and aberrant embryos after 48 h of culture. Our findings showed a direct impact of neonatal androgens on oocyte development; their effects may be recognized at adulthood, supporting the idea of a programming effect exerted by neonatal androgens. These results could be relevant to explain the low fertility rate seen in polycystic ovary syndrome patients after in vitro fertilization procedures.

Prenatal and pubertal exposure to 17α-ethinylestradiol disrupts folliculogenesis and promotes morphophysiological changes in ovaries of old gerbils (Meriones unguiculatus)

17α-Ethinylestradiol is an endocrine-disrupting chemical that make up most contraceptive pills and can be found in the environment. Exposure to ethinylestradiol in different development periods may promote changes in morphophysiological parameters of reproductive and endocrine organs. Considering that the effects of low doses (15 µg/kg/day) of ethinylestradiol in ovaries from 12-month-old female gerbils (Meriones unguiculatus) were investigated. Four experimental groups used were control (without treatment), EE/PRE (treated from the 18th to the 22nd gestational day), EE/PUB (treated from the 42nd to the 49th day of life), and EE/PRE-PUB (treated in the both periods). The animals were euthanized at 12 months. Testosterone and 17β-estradiol levels were measured. The ovaries were stained with Hematoxylin and Eosin, Periodic Acid Schiff, and Gomori's Trichome. The follicles, corpus luteum, interstitial gland, lipofuscin, ovarian epithelium, and tunica albuginea were analyzed. Estradiol was higher in EE/PRE and EE/PUB groups, while testosterone was higher only in EE/PUB group. The main changes in follicle count occurred in EE/PUB and EE/PRE-PUB groups, with higher primordial follicle count and lower maturation of follicles. The corpus luteum was more evident in EE/PRE group. No differences were found in atretic follicles count. A higher area occupied by interstitial gland cells and lipofuscin deposit in these cells was noted in EE/PUB and EE/PRE-PUB groups. Higher epithelium height and thicker tunic albuginea were showed in treated groups. These results suggest that exposure to doses of EE2 in prenatal and pubertal periods of the development leads to morphological changes in senile ovaries.

Follicle-stimulating hormone and luteinizing hormone regulate the synthesis mechanism of dihydrotestosterone in sheep granulosa cells

Steroid hormones and receptors play important roles in female reproduction, and their expression patterns affect follicular growth and development. To examine the expression of dihydrotestosterone (DHT) synthases (5α-reductases (5α-red1 and 5α-red2)) and androgen receptor (AR) during follicular development, and the regulation of DHT signalling by follicle-stimulating hormone (FSH) and luteinizing hormone (LH), we have used enzyme-linked immunosorbent assays, quantitative real-time polymerase chain reaction, immunohistochemical staining and Western blotting to examine DHT synthesis in small (≤2 mm), medium (2-5 mm) and large (≥5 mm) sheep follicles. Expression of 5α-red1, 5α-red2 and AR was observed in ovine ovaries, and with the development of follicles, the expressions of 5α-red1 and 5α-red2 mRNA and protein increased, but the levels of AR mRNA, protein and DHT level decreased. In addition, granulosa cells were treated with FSH (0.01, 0.1 and 1 international unit (IU)/ml), LH (0.01, 0.1 and 1 IU/ml) and testosterone (T, 10^-7  M) to evaluate the effects of FSH and LH on DHT and oestradiol (E2) synthesis and 5α-red1, 5α-red2 and AR expression. We found that FSH and LH upregulated 5α-red1 and 5α-red2 in sheep granulosa cells, but downregulated the concentration of DHT and expression of AR. Meanwhile, FSH and LH significantly upregulated the expression of aromatase (P450arom) and secretion of E2. This result indicates that although FSH and LH promote the expression of 5α-red1 and 5α-red2, T is not transformed into DHT, but E2. This study reveals the reason why DHT concentration is downregulated in large follicles and lays a foundation for further exploring the synthesis mechanism of DHT during follicular development.

Dietary combined supplementation of iron and Bacillus subtilis enhances reproductive performance, eggshell quality, nutrient digestibility, antioxidant capacity, and hematopoietic function in breeder geese

A 3 × 2 factorial arrangement of treatments was conducted to investigate the effects of iron (Fe, 40, 60, and 80 mg/kg) and Bacillus subtilis (2.5 × 10⁹ and 5.0 × 10⁹ CFU/kg) supplementation on reproductive performance, egg quality, nutrient digestibility, hormone levels, antioxidant indices, and hematological parameters in breeder geese. A total of one hundredtwenty 46-week-old Wulong breeder geese were randomly assigned to 1 of 6 dietary treatments with 4 replicates per treatment and 5 geese per replicate for 10 wk following 1 wk of adaption. Dietary Fe supplementation increased egg weight (P = 0.036), fertility (P = 0.022), serum total antioxidant capacity (P = 0.022), red blood cell (P = 0.001), hematocrit (HCT, P < 0.001), hemoglobin (HGB, P = 0.005), and mean corpuscular volume (MCV, P < 0.001). Dietary B. subtilis supplementation increased egg production (P = 0.025), eggshell thickness (P = 0.020), apparent phosphorus digestibility (P < 0.001), serum follicle stimulating hormone (P = 0.043), total antioxidant capacity (P < 0.001), HCT (P < 0.001), HGB (P < 0.001), and MCV (P = 0.025), and reduced malondialdehyde level (P = 0.008). The birds fed diets supplemented with 60 mg/kg Fe and 5 × 10⁹ CFU/kg B. subtilis showed the highest percentage of hatched eggs (P = 0.004) and mean corpuscular hemoglobin (P < 0.001) among the 6 groups. Supplementation of 40 and 60 mg/kg Fe significantly increased the apparent digestibility of calcium compared with that of 80 mg/kg Fe in the birds fed 5.0 × 10⁹ CFU/kg B. subtilis (P = 0.004). Supplementation with 60 and 80 mg/kg Fe in the birds fed 5 × 10⁹ CFU/kg B. subtilis significantly decreased serum urea nitrogen level compared with other 4 groups (P = 0.022). In conclusion, the combination of Fe and B. subtilis effectively improves reproductive performance, eggshell quality, nutrient digestibility, antioxidant status, and hematopoietic function of breeder geese. Dietary addition of 60 mg/kg Fe and 5.0 × 10⁹ CFU/kg B. subtilis was an optimum supplementation dose.

LncPrep + 96kb 2.2 kb Inhibits Estradiol Secretion From Granulosa Cells by Inducing EDF1 Translocation

LncPrep + 96kb is a novel long non-coding RNA expressed in murine granulosa cells with two transcripts that are 2.2 and 2.8 kb in length. However, the potential roles of lncPrep + 96kb in granulosa cells remain poorly understood. In this study, we investigated the effect of the lncPrep + 96kb 2.2 kb transcript on granulosa cells through the overexpression and knockdown of lncPrep + 96kb 2.2 kb. We found that lncPrep + 96kb 2.2 kb inhibited aromatase expression and estradiol production. Endothelial differentiation-related factor 1 (EDF1) is an evolutionarily conserved transcriptional coactivator. We found that EDF1 knockdown inhibited aromatase expression and estradiol production. The RNA immunoprecipitation results also showed that lncPrep + 96kb 2.2 kb can bind to EDF1 and that overexpression of lncPrep + 96kb 2.2 kb induced the translocation of EDF1 from the nucleus to the cytoplasm. The CatRAPID signature revealed that the 1,979–2,077 and 603–690 nucleotide positions in lncPrep + 96kb 2.2 kb were potential binding sites for EDF1. We found that mutating the 1,979–2,077 site rescued the effects of lncPrep + 96kb 2.2 kb on aromatase expression and estradiol production. In conclusion, we are the first to report that specific expression of lncPrep + 96kb 2.2 kb in granulosa cells inhibits the production of estradiol by influencing the localization of EDF1 in granulosa cells. The 1,979–2,077 site of lncPrep + 96kb 2.2 kb contributes to the ability to bind to EDF1.

Effect of ovarian stimulation on the expression of piRNA pathway proteins

PIWI-interacting RNAs (piRNAs) play an important role in gametogenesis, fertility and embryonic development. The current study investigated the effect of different doses of pregnant mare serum gonadotrophin/human chorionic gonadotrophin (PMSG/hCG) and repeated ovarian stimulation (OS) on the expression of the Mili, Miwi, Mael, Tdrd1, Tdrd9, qnd Mitopld genes, which have crucial roles in the biogenesis and function of piRNAs. Here, we found that after treatment with 7.5 I.U. PMSG/hCG and two repeated rounds of OS, both the mRNA and protein levels of Tdrd9, Tdrd1 and Mael showed the greatest decrease in the ovarian tissue, but the plasma E₂ levels showed the strongest increases (p<0.05). However, we found that the Mitopld, Miwi and Mili gene levels were decreased significantly after treatment with 12.5 I.U. PMSG/hCG. Our results suggested that exogenous gonadotropin administration leads to a significant decrease in the expression of the Mili, Miwi, Mael, Tdrd1, Tdrd9 and Mitopld genes, which are critically important in the piRNA pathway, and the changes in the expression levels of Tdrd9, Tdrd1 and Mael may be associated with plasma E₂ levels. New comprehensive studies are needed to reduce the potential effects of OS on the piRNA pathway, which silences transposable elements and maintains genome integrity, and to contribute to the safety of OS.

Effect of curcumin on laying performance, egg quality, endocrine hormones, and immune activity in heat-stressed hens

This study was conducted to evaluate the effect of curcumin on laying performance, egg quality, biochemical indicators, hormone levels, and immune activity in hens under heat stress. Hy-Line brown hens (280-day-old) were fed with 0, 100, 150, and 200 mg/kg of curcumin during a 42-D experiment. Compared with the control treatment, supplementation with 150 mg/kg of curcumin improved laying performance and egg quality by significantly increasing egg production, eggshell thickness, eggshell strength (P < 0.01), and albumen height (P < 0.05) while decreasing the feed-to-egg ratio. Antioxidant activity was improved by significantly increasing the activity of superoxide dismutase and glutathione peroxidase but decreasing malondialdehyde levels in serum (P < 0.05) and significantly increasing the levels of follicle-stimulating hormone, luteinizing hormone, estradiol, IgG, IgA, and complement C₃ activity in serum (P < 0.05). These results indicated that supplemental 150 mg/kg curcumin can improve productive performance, antioxidant enzyme activity, and immune function in laying hens under the heat stress conditions applied in the present study.

The impact of peak estradiol during controlled ovarian stimulation on the cumulative live birth rate of IVF/ICSI in non-PCOS patients

OBJECTIVE

The study aimed to investigate the impact of the peak E2 level during controlled ovarian hyperstimulation (COS) on the cumulative live birth rate (cLBR) in non-PCOS women with normal ovarian reserve.

MATERIALS AND METHODS

Women between 20 and 39 years were included. Donor cycles and patients who never experienced embryo transfer were excluded. Multivariable regression and smooth curve fitting were applied for statistical analysis.

RESULTS

A total of 1141 patients were included. The mean age, basal AFC, peak E2 level, and number of retrieved oocyte were 30.0 ± 3.7 years old, 16.8 ± 6.7, 3911.0 ± 1302.9 pg/ml, and 13.6 ± 5.5, respectively. In the overall population of the cohort, cLBR, miscarriage rate, and preterm birth rate were 66.9%, 7.4%, and 13.7%, respectively. The results of multivariable regression analysis failed to show the impact of peak E2 on the cLBR [OR (95%CI) 0.995 (0.982, 1.009), P = 0.486]. However, the result of smooth curve fitting indicated that when the peak E2 was lower than 2185 pg/ml, the cLBR increased about 12% with 100 pg/ml increasing of the peak E2. When the peak E2 was higher than 6136 pg/ml, the cLBR decreased about 10% with 100 pg/ml increasing of the peak E2.

CONCLUSION

We concluded that the peak E2 level on hCG trigger day is associated with the cLBR in a segmental pattern. There should be an appropriate range of the peak E2 level during COS to achieve a relative best cLBR in non-PCOS patients using stimulating protocol mainly based on GnRH agonist; however, the cutoff value must vary in different centers.

Transcriptomic Analysis Revealed the Regulatory Mechanisms of Oocyte Maturation and Hydration in Orange-Spotted Grouper (Epinephelus coioides)

Oocyte maturation and hydration are regulated by a complex interplay of various hormones and local factors. We have investigated the morphological changes of follicles and serum steroid levels during the HCG (human choionic gonadotophin)-induced oocyte maturation in the orange-spotted grouper. For the first time, a large-scale transcriptomic analysis of follicles during the maturation has been conducted in a fish species which produce pelagic oocytes. Eight cDNA libraries of follicle samples, from full-grown immature follicles to mature follicles, were constructed. A total of 402,530,284 high-quality clean reads were obtained after filtering, 79.66% of which perfectly mapped to the orange-spotted grouper genome. Real-time PCR results of 12 representative genes related to oocyte maturation and hydration verified the reliability of the RNA-seq data. A large number of genes related to oocyte maturation and hydration were identified in the transcriptome dataset. And the transcriptomic analysis revealed the dynamic changes of the steroid synthesis pathway and the pathway of hydration during oocyte maturation. The present study will facilitate future study on the oocyte maturation and hydration in the orange-spotted grouper and other marine pelagic egg spawner.

Shaoyao-Gancao Decoction alleviated hyperandrogenism in a letrozole-induced rat model of polycystic ovary syndrome by inhibition of NF-κB activation

Shaoyao-Gancao Decoction (SGD) has been widely used for the treatment of gynopathy. The present study aimed to evaluate the therapeutic effect and potential mechanism of SGD on hyperandrogenism in polycystic ovary syndrome (PCOS) rats. In the present work, SGD was orally administrated to the PCOS rats at the dose of 12.5, 25, and 50 g/kg/d for 14 consecutive days. UPLC–MS/MS was performed to identify the main chemical components of SGD. Body weight, ovarian weight, cystic dilating follicles, and serum levels of steroid hormones were tested to evaluate the therapeutic effect of SGD. In order to further clarify the underlying mechanism, we also measured mRNA and the protein levels of NF-κB, NF-κB p65, P-NF-κB p65, and IκB by RT-qPCR and Western blotting techniques. Our results showed that SGD treatment significantly alleviated hyperandrogenism in PCOS rats as evidenced by reduced serum levels of T and increased E₂ and FSH levels. In addition, SGD effectively reduced the phosphorylation of NF-κB p65 and increased the expression of IκB. Results of the present study demonstrated that SGD could ameliorate hyperandrogenism in PCOS rats, and the potential mechanism may relate to the NF-κB pathway.

Dietary vitamin D3 supplementation protects laying hens against lipopolysaccharide-induced immunological stress

Background

The effects of vitamin D on the immune function of laying hens are not well understood. This study investigated the effects of vitamin D₃ (VD₃) on laying performance and immunological functions in laying hens under Escherichia coli lipopolysaccharide (LPS) challenge.

Methods

In experiment one, 360 Jinghong-1 strain layers (32 weeks) were randomly divided into four groups with six replicates per group and 15 hens per replicate. Hens were fed a basal diet supplemented with different levels of VD₃ (0; 500; 1500; or 3000 IU VD₃/kg of diet) for 10 weeks to determine laying performance, egg quality, and other parameters. In experiment two, 24 Jinghong laying hens (32 weeks) were fed basal diets with either 0 or 3000 IU VD₃/kg of diet. After 10 weeks of feeding, six hens from each treatment were injected intravenously with 8 mg/kg of body weight of either LPS or saline. Blood and spleen samples were obtained for immune parameter analysis 4 h after injection.

Results

VD₃ deficiency reduced egg production and egg quality; in addition, feed intake and feed-to-egg ratio increased. No significant differences were observed in these parameters except eggshell strength between dietary VD₃ supplemental levels at 500; 1500; and 3000 IU VD₃/kg of diet. VD₃ deficiency increased serum hormone (calcitonin, parathyroid hormone, estradiol, and progesterone) and cytokine (IL-6, IL-10) levels, the ratio of IFN-γ to IL-4, myeloperoxidase activity and total IgG content in the serum, and upregulated the blood CD3⁺ T cell population. Splenic retinoid X receptor (RXR), nuclear factor-κB (NF-κB), inducible nitric oxide synthase (iNOS), and polymeric immunoglobulin receptor (pIgR) gene mRNA levels were upregulated in VD₃-deficienct hens. VD₃ deficiency significantly reduced serum Follicle stimulating hormone (FSH) and Luteinizing hormone (LH) concentrations and the number of CD4⁺CD25⁺ T cells in the blood. These changes were completely normalized by VD₃ sufficiency. LPS reduced serum LH concentration, splenic lysozyme, and pIgR gene mRNA levels. LPS induced an increase in total serum IgM levels and the percentage of CD8⁺ T cells in the blood. The changes were completely reversed by VD₃ addition.

Conclusion

VD₃ supplementation could protect laying hens not only from VD₃ deficiency but also from immunological stress.

Establishment of an improved vitrification protocol by combinations of vitrification medium for isolated mouse ovarian follicles

In vitro follicle growth (IVFG) is an emerging alternative option for fertility preservation in women instead of ovarian tissue cryopreservation and transplantation. To widen the application of this technique, follicle cryopreservation should be established prior to clinical use. In the present study, we tried to determine the optimal vitrification protocol of mouse ovarian follicle for in vitro culture and oocyte maturation by comparing four different compositions of cryoprotective agents (CPA). Secondary follicles were mechanically isolated from 2-week-old BDF-1 mice and randomly assigned to fresh control and four different groups by the composition of CPAs (ES, EDS, EFS and EPS groups; E: ethylene glycol, D: dimethyl sulfoxide, S: sucrose, F: ficoll, P: 1,2-propanediol (PROH)). After vitrification and warming procedures, the follicles were cultured in vitro for 10 days and then treated with human chorionic gonadotropin and epidermal growth factor to induce oocyte maturation. Fourteen to 16 h later, oocyte maturation and quality were assessed. Follicle viability was evaluated by Calcein-AM/ethidium homodimer-1 staining immediately after warming, and their survival and diameters were measured during follicle culture periods. Antral cavity formation was observed at the end of the culture period (on the 10th day of culture). Following oocyte maturation, its maturational ability and meiotic spindle formation were assessed to evaluate their competence. There was no significant difference in viability after warming among the vitrification groups. From the 8th day of culture, the survival rate of ES and EDS were significantly higher than those of other vitrification groups (EPS and EFS). The follicle diameter was largest in the fresh-control group from the 6th day, while smallest in the EFS with statistical significance. On the 10th day of culture, the antral-cavity formation rate of EDS was comparable to that of the fresh control group. However, the oocyte maturation was significantly decreased in all four vitrification groups when compared with control group; especially, the EFS showed a more marked reduction in the oocyte maturation. There were no significant differences in meiotic spindle formation among all of those groups. Our results suggest that EDS combination for mouse follicle vitrification are the most effective vitrification protocols for mouse follicle and evaluated by an in vitro culture and oocyte maturation after warming.

Histopathological changes in androgenized ovaries are recovered by melatonin treatment

Nandrolone decanoate (ND) is a synthetic steroid, which promotes adverse effects on the ovarian tissue, and melatonin (MLT) exhibits a number of beneficial properties in the reproductive system. This study evaluated the general features of the ovarian tissue and the immunoexpression of sex steroid receptors in ND-treated rats that were submitted to short-term melatonin treatment. Adult rats received mineral oil (control group) and ND at doses of 7.5 mg/kg for 15 days (ND-treated group). The treatment with MLT (10mg/kg for 7 days) was given alone, before or in combination with ND. All ND-treated animals showed persistent dioestrus. In the androgenized groups that received MLT, ovarian morphology and size, and the number/area of corpora lutea were recovered. The number of healthy and atretic follicles was recovered when MLT was administered prior to ND; this was similar to the ovaries of control and MLT groups. There was a decrease in estrogen receptors immunostaining in the follicles of androgenized rats that were treated with MLT, and pretreatment with MLT reduced the expression of androgen receptor in atretic follicles and corpora lutea, when compared with ND-treated group. We conclude that MLT treatment recovered the histopathological aspects of the androgenized ovaries, and MLT pretreatment was the most effective.

Comparison of the Oocyte Quality Derived from Two-Dimensional Follicle Culture Methods and Developmental Competence of In Vitro Grown and Matured Oocytes

In vitro follicle growth (IVFG) is an emerging fertility preservation technique, which can obtain fertilizable oocytes from an in vitro culture system in female. This study aimed to compare efficiency of the most widely used two-dimensional follicle culture methods [with or without oil layer (O+ or O- group)]. Preantral follicles were isolated from mice and randomly assigned. Follicles were cultured for 10 days and cumulus-oocyte complexes harvested 16-18 hours after hCG treatment. Follicle and oocyte growth, hormones in spent medium, meiotic spindle localization, expression of reactive oxygen species (ROS), mitochondrial activity, and gene expression were evaluated. In follicle growth, survival, pseudoantral cavity formation, ovulation, and oocyte maturation were also significantly higher in O+ group than O- group. Hormone production was significantly higher in follicles cultured in O+ than O-. There were no significant differences in mRNA expression related to development. On the other hand, the level of ROS was increased while the mitochondrial activity of in vitro grown matured oocyte was less than in vivo matured oocytes. In conclusion, follicle culture with O+ group appears to be superior to the culture in O- group in terms of follicle growth, development, oocyte growth, maturation, and microorganelles in oocyte.

miR-1275 controls granulosa cell apoptosis and estradiol synthesis by impairing LRH-1/CYP19A1 axis

miR-1275 is one of the microRNAs (miRNAs) that are differentially expressed during follicular atresia in pig ovaries, as identified by a miRNA microarray assay in our previous study [1]. However, its functions in follicular atresia remain unknown. In this study, we showed that miR-1275 promotes early apoptosis of porcine granulosa cells (pGCs) and the initiation of follicular atresia, and inhibits E2 release and expression of CYP19A1, the key gene in E2 production. Bioinformatics and luciferase reporter assays revealed that liver receptor homolog (LRH)-1, not CYP19A1, is a direct functional target of miR-1275. In vitro overexpression and knockdown experiments showed that LRH-1 significantly repressed apoptosis and induced E2 secretion and CYP19A1 expression in pGCs. LRH-1, whose expression was regulated by miR-1275, prevented apoptosis in pGCs. Furthermore, luciferase and chromatin immunoprecipitation assays demonstrated that LRH-1 protein bound to the CYP19A1 promoter and increased its activity. Our findings suggest that miR-1275 attenuates LRH-1 expression by directly binding to its 3'UTR. This prevents the interaction of LRH-1 protein with the CYP19A1 promoter, represses E2 synthesis, promotes pGC apoptosis, and initiates follicular atresia in porcine ovaries.

4-Nitrophenol (PNP) inhibits the expression of estrogen receptor β and disrupts steroidogenesis during the ovarian development in female rats

4-nitrophenol (PNP), isolated from diesel exhaust particles, has estrogenic and anti-androgenic activities, and affects the hypothalamus-pituitary-gonad axis in male rats. However, the effect of PNP on the reproduction of the female rats is still unknown. The aim of the study was to investigate the effect of neonatal PNP exposure on the ovarian function of female rats. The neonatal female rats were exposed to PNP (10 mg/kg, subcutaneously injection), the ovary and serum samples were collected at postnatal day (PND) 7, 14 and 21. The results showed that the ratio of primordial and primary follicles increased whereas the ratio of antral follicles decreased in the PNP treated ovaries at PND21. Even though no abnormality was observed in cyclicity, there was a significantly delayed timing of vaginal opening in PNP treated rats. The ovarian expression of steroidogenic enzymes including StAR, P450scc, P450c17 and P450arom increased at PND14 in the PNP treated rats compared with the control rats. In consistent with the gene expression, the concentration of estradiol-17β showed the similar pattern. However, PNP exposure failed to cause any significant change in the expression of steroidogenic enzymes in cultured neonatal ovaries. Furthermore, PNP suppressed the expression of estrogen receptor β (ERβ), but not estrogen receptor α (ERα), in cultured ovaries or developmental ovaries. These results suggested that PNP might directly affect the expression of ERβ in the rat ovaries, resulting in the disrupted steroidogenesis during ovarian development and the delayed puberty.

Potential role of polyunsaturated fatty acids, with particular regard to the signaling pathways of arachidonic acid and its derivatives in the process of maturation of the oocytes: Contemporary review

Oocyte meiotic maturation is one of the significant physiological requirements for ovulation and fertility. It is believed that Cyclic Adenosine Monophosphate, protein kinase A and protein kinase C pathways along with eicosanoids, particularly prostaglandin E_2, and steroids are the key factors regulating mammalian oocyte maturation. The aim of the current study was to highlight the molecular events triggered by arachidonic acid during oocyte meiotic arrest and resumption at the time of gonadotrophin surge. It should be noted that arachidonic acid release is tightly regulated by Follicle-stimulating and Luteinizing hormones during oocyte development.

The Steroid Metabolome in the Isolated Ovarian Follicle and Its Response to Androgen Exposure and Antagonism

The ovarian follicle is a major site of steroidogenesis, crucially required for normal ovarian function and female reproduction. Our understanding of androgen synthesis and metabolism in the developing follicle has been limited by the sensitivity and specificity issues of previously used assays. Here we used liquid chromatography-tandem mass spectrometry to map the stage-dependent endogenous steroid metabolome in an encapsulated in vitro follicle growth system, from murine secondary through antral follicles. Furthermore, follicles were cultured in the presence of androgen precursors, nonaromatizable active androgen, and androgen receptor (AR) antagonists to assess effects on steroidogenesis and follicle development. Cultured follicles showed a stage-dependent increase in endogenous androgen, estrogen, and progesterone production, and incubations with the sex steroid precursor dehydroepiandrosterone revealed the follicle as capable of active androgen synthesis at early developmental stages. Androgen exposure and antagonism demonstrated AR-mediated effects on follicle growth and antrum formation that followed a biphasic pattern, with low levels of androgens inducing more rapid follicle maturation and high doses inhibiting oocyte maturation and follicle growth. Crucially, our study provides evidence for an intrafollicular feedback circuit regulating steroidogenesis, with decreased follicle androgen synthesis after exogenous androgen exposure and increased androgen output after additional AR antagonist treatment. We propose that this feedback circuit helps maintain an equilibrium of androgen exposure in the developing follicle. The observed biphasic response of follicle growth and function in increasing androgen supplementations has implications for our understanding of polycystic ovary syndrome pathophysiology and the dose-dependent utility of androgens in in vitro fertilization settings.

Effects of dietary octacosanol supplementation on laying performance, egg quality, serum hormone levels, and expression of genes related to the reproductive axis in laying hens

This experiment was conducted to evaluate the effects of dietary octacosanol supplementation on laying performance, egg quality, serum hormone levels, and gene expression related to reproductive axis in laying hens to confirm the reproduction-promoting function of octacosanol. In total, 360 Hy-Line Brown (67-wk-old) laying hens were randomly assigned to one of three treatments with 0, 5, and 10 mg octacosanol (extracted from rice bran, purity >92%)/kg feed. The feeding trial lasted for 10 weeks. The results showed that the dietary addition of 5 and 10 mg/kg octacosanol improved feed efficiency by 4.9% and 3.4% (P < 0.01), increased the albumen height by 20.5% and 13.3% (P < 0.01), the Haugh unit score by 12.9% and 8.7% (P < 0.01), and the eggshell strength by 39.5% and 24.5% (P < 0.01), respectively, compared with the control diet. Dietary octacosanol addition significantly affected serum triiodothyronine, estradiol, follicle-stimulating hormone levels (P < 0.05), and progesterone and luteinizing hormone level (P < 0.01). Compared with the control, dietary addition of octacosanol at 5 mg/kg promoted the follicle-stimulating hormone receptor (FSHR) mRNA expression in different-sized follicles, and significantly increased the FSHR mRNA expression of granulosa cells from the F2 and F3 follicles (P < 0.05). Dietary supplementation with both 5 and 10 mg/kg octacosanol promoted the mRNA expression of luteinizing hormone receptor and prolactin receptor in different-sized follicles, and significantly up-regulated the expression levels in F1 granulosa cells (P < 0.05). The ovarian weight was significantly increased with the dietary addition of 5 mg/kg octacosanol (P < 0.05). The numbers of small yellow follicles and large white follicles were increased with the addition of dietary 5 and 10 mg/kg octacosanol (P < 0.01). This study provides evidence that octacosanol has the capacity to improve reproductive performance, indicating that it is a potentially effective feed additive in egg production.

Brain-derived neurotrophic factor promotes human granulosa-like tumor cell steroidogenesis and proliferation by activating the FSH receptor-mediated signaling pathway

Brain-derived neurotrophic factor (BDNF) and FSH receptor (FSHR) are expressed in ovarian granulosa cells, and play important roles in regulating follicle growth and oocyte maturation. Studies have linked the BDNF-associated signaling pathway to FSHR mRNA expression in the regulation of follicle development, but the mechanisms remain unknown. In the current study, we found that BDNF stimulated the secretion of estradiol and progesterone, and increased the proliferation of KGN cells (human granulosa-like tumor cell line). BDNF treatment also increased phosphorylated and ubiquitinated FSHR, and activated cAMP/PKA/CREB signaling pathway. Moreover, inhibition of BDNF expression by siRNA markedly reduced the estradiol secretion and down-regulated FSHR, aromatase and phosphorylated CREB; meanwhile, FSH treatment partly alleviated the effects of BDNF siRNA on KGN cells. These findings suggested that BDNF modulates graunlosa cell functions and the action probably mediated by FSHR-coupled signaling pathway, to affect aromatase-mediated steroidogenesis. These results provide an alternative target to optimize ovarian granulosa cell function.

Differential effects of estrogen and progesterone on development of primate secondary follicles in a steroid-depleted milieu in vitro

STUDY QUESTION

What are the direct effects of progesterone (P4) and estradiol (E2) on the development and function of primate follicles in vitro from the pre-antral to early antral stage?

SUMMARY ANSWER

In a steroid-depleted milieu, E2 improved follicle survival, growth, antrum formation and oocyte health, whereas P4 exerted minimal beneficial effects on follicle survival and reduced oocyte health.

WHAT IS KNOWN ALREADY

Effects of P4 and E2 on follicle development have been studied primarily in large antral and pre-ovulatory follicles. Chronic P4 exposure suppresses antral follicle growth, but acute P4 exposure promotes oocyte maturation in pre-ovulatory follicles. Effects of E2 can be stimulatory or inhibitory depending upon species, dose and duration of exposure.

STUDY DESIGN, SIZE, DURATION

Non-human primate model, randomized, control versus treatment. Macaque (n = 6) secondary follicles (n = 24 per animal per treatment group) were cultured for 5 weeks.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Adult rhesus macaque secondary follicles were encapsulated in 0.25% alginate and cultured individually in media containing follicle stimulating hormone plus (i) vehicle, (ii) a steroid-synthesis inhibitor, trilostane (TRL, 250 ng/ml), (iii) TRL + low E2 (100 pg/ml) or progestin (P, 10 ng/ml R5020) and (iv) TRL + high E2 (1 ng/ml E2) or P (100 ng/ml R5020). Follicles reaching the antral stage (≥750 µm) were treated with human chorionic gonadotrophin for 34 h. End-points included follicle survival, antrum formation, growth pattern, plus oocyte health and maturation status, as well as media concentrations of P4, E2 and anti-Müllerian hormone (AMH).

MAIN RESULTS AND THE ROLE OF CHANCE

In a steroid-depleted milieu, low dose, but not high dose, P improved (P < 0.05) follicle survival, but had no effect (P > 0.05) on antrum formation and AMH production. Low-dose P increased (P < 0.05) P4 production in fast-grow follicles, and both doses of P elevated (P < 0.05) E2 production in slow-grow follicles. Additionally, low-dose P increased (P < 0.05) the percentage of no-grow follicles, and high-dose P promoted oocyte degeneration. In contrast, E2, in a steroid-depleted milieu, improved (P < 0.05) follicle survival, growth, antrum formation and oocyte health. E2 had no effect on P4 or E2 production. Follicles exposed to E2 yielded mature oocytes capable of fertilization and early cleavage, at a rate similar to untreated control follicles.

LIMITATIONS, REASONS FOR CAUTION

This study is limited to in vitro effects of P and E2 during the interval from the secondary to small antral stage of macaque follicles.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides novel information on the direct actions of P4 and E2 on primate pre-antral follicle development. Combined with our previous report on the actions of androgens, our findings suggest that androgens appear to be a survival factor but hinder antral follicle differentiation, E2 appears to be a survival and growth factor at the pre-antral and early antral stage, whereas P4 may not be essential during early folliculogenesis in primates.

STUDY FUNDING/COMPETING INTERESTS

NIH P50 HD071836 (NCTRI), NIH ORWH/NICHD 2K12HD043488 (BIRCWH), ONPRC 8P51OD011092. There are no conflicts of interest.