Effects of vitamin D supplementation on ovulation and pregnancy in women with polycystic ovary syndrome: a systematic review and meta-analysis.

Objective: To evaluate the effect of vitamin D supplementation on pregnancy and ovulation in patients with polycystic ovary syndrome. Method: We searched Pubmed, Medline (via Ovid, 1974 to 2020), EMBASE (via Ovid, 1974 to 2020), Cochrane Central Register of Controlled Trials (via Ovid), Web of Science, CNKI, WangFang and the Vip database from inception until April 2021. Two researchers independently screened articles, collected data and evaluated the quality, with Review manager 5.3 for meta-analysis. Results: Totally 20 randomized controlled studies with 1961 subjects were included. Meta analysis showed that pregnancy rate [RR=1.44 (1.28, 1.62), p<0.00,001], ovulation rate [RR=1.42 (1.14, 1.78), p=0.002] and matured oocytes rate [RR=1.08 (1.03, 1.13), p=0.002] of vitamin D supplementation group were significantly higher than those of control group. Meanwhile, early miscarriage rate [RR=0.44 (0.30, 0.66), p<0.00,001], androgen level [MD=-2.31 (-3.51, -1.11), p=0.0002], luteinizing hormone [MD=-1.47 (-2.57, -0.36), p=0.009], follicle stimulating hormone [MD=-0.15 (-0.24, -0.05), p=0.002], and premature delivery rate [RR=0.38, 95% CI (0.21, 0.70), p=0.002] were declined significantly than the controls. However, only one article suggested that the progesterone [MD=6.52 (4.52, 8.52), p<0.05] in the vitamin D intervention group was increased. There was no notable difference in the biochemical pregnancy rate [RR=0.95 (0.55, 1.63), p=0.84], gestational hypertension rate [RR=0.40, 95% CI (0.15, 1.11), p=0.08], gestational diabetes mellitus rate [RR=0.27, 95% CI (0.05, 1.39), p=0.11], fertilization rate [RR=1.05 (1.00, 1.10), p=0.04], cleavage rate [RR=1.03 (0.99, 1.06), p=0.17], high-quality embryo rate [RR=1.08 (0.98, 1.20), p=0.10], endometrial thickness [MD=0.10], 77 (-0.23, 1.77), p=0.13], estrogen level [MD=-0.34 (-1.55, 0.87), p=0.59], LH/FSH [MD=-0.14, 95% CI (-0.48, 0.20), p=1.00] and anti-Mullerian hormone [MD=-0.22 (-0.65, 0.21), p=0.32]. Conclusion: Vitamin D supplementation contribute to the higher pregnancy and ovulation rates, and lower androgen, LH, FSH and early miscarriage rates in women with PCOS, regardless of the use of ovulation induction drugs or assisted reproductive technologies. However, no significant improvement was observed in fertilization rate or cleavage rate. Due to the limitation in quality of involved studies, more high-quality RCTs are needed for further validation. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO, identifier CRD42021250284.

Luteinised unruptured follicle syndrome: pathophysiological background and new target therapy in assisted reproductive treatments.

Luteinised unruptured follicle syndrome (LUFS) is a cause of infertility consisting in the unruptured of the dominant follicle after the LH-surge. In fact, during assisted reproductive treatments (ART) clomiphene citrate and letrozole are frequently administered in order to achieve ovulation. However, considering the pathophysiology of LUFS, new possible therapy can be proposed. On this scenario, we performed a review of the literature searching for LUFS recurrency and its impact in infertility and ART. An inflammation theory has been proposed that can be fuel for further therapeutic possibilities. In particular, considering the increase in granulocytes accumulation, the granulocyte colony-stimulating factor (G-CSF) administration has been proposed as target therapy in IUI cycles hampered by LUFS. Although data are encouraging, randomised controlled trials are needed in order to confirm the efficacy of G-CSF administration for LUFS patients.

A customized long acting formulation of the kisspeptin analog C6 triggers ovulation in anestrus ewe.

The modulation of the kisspeptin system holds promise as a treatment for human reproductive disorders and for managing livestock breeding. The design of analogs has overcome some unfavorable properties of the endogenous ligands. However, for applications requiring a prolongation of drug activity, such as ovulation induction in the ewe during the non-breeding season, additional improvement is required. To this aim, we designed and tested three formulations containing the kisspeptin analog C6. Two were based on polymeric nanoparticles (NP1 and NP2) and the third was based on hydrogels composed of a mixture of cyclodextrin polymers and dextran grafted with alkyl side chains (MD/pCD). Only the MD/pCD formulation prolonged C6 activity, as shown by monitoring luteinizing hormone (LH) plasma concentration (elevation duration 23.4 ± 6.1, 13.7 ± 4.7 and 12.0 ± 2.4 h for MD/pCD, NP1 and NP2, respectively). When compared with the free C6 (15 nmol/ewe), the formulated (MD/pCD) doses of 10, 15 and 30 nmol/ewe, but not the 90 nmol/ewe dose, provided a more gradual release of C6 as shown by an attenuated LH release during the first 6 h post-treatment. When tested during the non-breeding season without progestogen priming, only, the formulated 30 nmol/ewe dose triggered ovulation (50% of ewes). Hence, we showed that a formulation with an adapted action time would improve the efficacy of C6 with respect to inducing ovulation during the non-breeding season. This result suggests that formulations containing a kisspeptin analog might find applications in the management of livestock reproduction but also point to the possibility of their use for the treatment of some human reproductive pathologies.

Chronic Estrus Disrupts Uterine Gland Development and Homeostasis.

Female mice homozygous for an engineered Gnrhr E90K mutation have reduced gonadotropin-releasing hormone signaling, leading to infertility. Their ovaries have numerous antral follicles but no corpora lutea, indicating a block to ovulation. These mutants have high levels of circulating estradiol and low progesterone, indicating a state of persistent estrus. This mouse model provided a unique opportunity to examine the lack of cyclic levels of ovarian hormones on uterine gland biology. Although uterine gland development appeared similar to controls during prepubertal development, it was compromised during adolescence in the mutants. By age 20 weeks, uterine gland development was comparable to controls, but pathologies, including cribriform glandular structures, were observed. Induction of ovulations by periodic human chorionic gonadotropin treatment did not rescue postpubertal uterine gland development. Interestingly, progesterone receptor knockout mice, which lack progesterone signaling, also have defects in postpubertal uterine gland development. However, progesterone treatment did not rescue postpubertal uterine gland development. These studies indicate that chronically elevated levels of estradiol with low progesterone and therefore an absence of cyclic ovarian hormone secretion disrupts postpubertal uterine gland development and homeostasis.

The effectiveness of desogestrel for endometrial protection in women with abnormal uterine bleeding-ovulatory dysfunction: a non-inferiority randomized controlled trial.

Women with chronic abnormal uterine bleeding-ovulatory dysfunction (AUB-O) are at increased risk of endometrial neoplasia. We conducted a non-inferiority randomized controlled trial to determine the effectiveness of two cyclic-progestin regimens orally administered 10 d/month for 6 months on endometrial protection and menstruation normalization in women with AUB-O. There were 104 premenopausal women with AUB-O randomized to desogestrel (DSG 150 µg/d, n = 50) or medroxyprogesterone acetate (MPA 10 mg/d, n = 54) group. Both groups were comparable in age (44.8 ± 5.7 vs. 42.5 ± 7.1 years), body mass index (24.8 ± 4.7 vs. 24.9 ± 4.7 kg/m2), and AUB characteristics (100% irregular periods). The primary outcome was endometrial response rate (the proportion of patients having complete pseudodecidualization in endometrial biopsies during treatment cycle-1). The secondary outcome was clinical response rate (the proportion of progestin withdrawal bleeding episodes with acceptable bleeding characteristics during treatment cycle-2 to cycle-6). DSG was not inferior to MPA regarding the endometrial protection (endometrial response rate of 78.0% vs. 70.4%, 95% CI of difference - 9.1-24.4%, non-inferiority limit of - 10%), but it was less effective regarding the menstruation normalization (acceptable bleeding rate of 90.0% vs 96.6%, P = 0.016).Clinical trial registration: ClinicalTrials.gov (NCT02103764, date of approval 18 Feb 2014).

Modulatory effects of R10 fraction of garlic (Allium sativum L.) on hormonal levels, T cell polarization, and fertility-related genes in mice model of polycystic ovarian syndrome.

Polycystic ovary syndrome (PCOS) is an inflammatory endocrine-metabolic disorder related to reproductive system characterized by polycystic ovarian morphology, androgen excess, and chronic anovulation. Current treatments haven't been very successful in PCOS treatment and the problem still remains as a challenge. Therefore, new approaches should be applied to overcome the disease. Previous studies demonstrated immunomodulatory effects of R10 fraction of garlic in the treatment of inflammatory conditions such as cancer. Considering previous studies suggesting immunomodulatory therapy for PCOS, therapeutic effects of R10 fraction was evaluated in a mouse model of PCOS. To do so, PCOS was developed by intramuscular injection of estradiol valerate. Treatment with R10 fraction, isolated from garlic, was performed and the alterations in hormonal levels (estradiol, progesterone, and testosterone), T cell polarization markers (IFN-γ, IL-4, and IL-17), and expression of fertility-related genes (Gpx3 and Ptx3) were evaluated. The results showed that hormonal levels were elevated in PCOS model comparing to normal animals but were markedly modulated after treatment with R10 fraction. Moreover, a severe disturbance in T cell polarization with a significant reduction of fertility-related genes expression were detected in PCOS-induced ovaries. Treatment with R10 fraction also represented modulatory effects on T cell polarization by increasing IL-4 and decreasing IL-17 and IFN-γ levels. Accordingly, fertility-related genes were also modulated following treatment with R10 fraction in PCOS. Our study elucidated that R10 fraction of garlic possess immunomodulatory effects alleviating PCOS symptoms. This approach could be adjusted to give rise the optimum therapeutic results and considered as a candidate therapeutic approach for PCOS.

YAP signaling in preovulatory granulosa cells is critical for the functioning of the EGF network during ovulation.

Failure to ovulate is a major cause of infertility. The critical pathway that induces ovulation involves the EGF and MAPK phosphorylation, but studies in rodents have suggested that the Hippo activator, YAP, is also involved. It is unknown whether YAP-dependent transcriptional activity is important for the LH- or EGF-induced ovulatory cascade in monovulatory species such as the cow. Using a well-defined preovulatory GC culture system, we employed pharmacological inhibitors to demonstrate that YAP signaling is critical for expression of EGFR and downstream target genes EREG, EGR1 and TNFAIP6. Most importantly, by using an ultrasound guided follicle injection system, we also showed that the classic Hippo signaling inhibitor Verteporfin inhibits GnRH-induced ovulation in vivo in cattle. In conclusion, YAP transcriptional activity is critical for EGF-like cascade induced by LH to promote ovulation in a monovulatory species.

Fixed Gonadotropin-Releasing Hormone Antagonist Protocol Versus Flexible Progestin-Primed Ovarian Stimulation Protocol in Patients With Asynchronous Follicular Development During Controlled Ovulation Stimulation: A Retrospective Study.

Protocols utilizing gonadotropin-releasing hormone (GnRH) antagonists have emerged as mainstream procedures for ovarian stimulation; however, GnRH increases the risk for periodic cancellation of embryos. Therefore, this study aimed to compare the pregnancy outcomes of a fixed GnRH antagonist protocol and a flexible progestin-primed ovarian stimulation (fPPOS) protocol in patients with asynchronous follicular development during controlled ovulation stimulation and to explore the feasibility of converting patients undergoing a fixed GnRH antagonist protocol to an fPPOS protocol. This was the first retrospective study exploring the fPPOS protocol in patients with asynchronous follicular development, and it was conducted in a public reproductive medicine center from January to December 2020. We included infertile women. All participants were scheduled to undergo administration of a GnRH antagonist on the fifth day of controlled ovulation stimulation. The study group included 129 women who were converted from the fixed GnRH antagonist protocol to the fPPOS protocol for their asynchronous follicular development, while the antagonist group consisted of 258 women (ratio 1:2) who proceeded with a fixed GnRH antagonist protocol. On the second or third day of the menstrual period, 100-300 IU/day gonadotropin injections were administered. For patients who were converted to the fPPOS protocol, medroxyprogesterone acetate tablets at 10 mg/day were started on the fifth day of stimulation or when only one leading follicle reached 14 mm and the other follicles were ≤10 mm in diameter, whichever came first. The rates of embryo implantation, clinical pregnancy, and early pregnancy loss were obtained. The number of oocytes retrieved and the number of high-quality embryos in the antagonist group were significantly higher than those in the fPPOS group (P = 0.039 and P = 0.025, respectively). No significant differences in the rates of embryo implantation, clinical pregnancy, and early pregnancy loss were observed between the two groups. Our study found that in patients who were scheduled for administration of GnRH antagonists but presented with asynchronous follicular development on the fifth stimulation day, it was feasible to switch to the fPPOS protocol.

Improved reproductive performance achieved in tropical dairy cows by dietary beta-carotene supplementation.

Dairy farming in tropical climates is challenging as heat stress can impair reproduction in cows. Previous studies have demonstrated the beneficial effects of beta-carotene supplementation on bovine reproductive performance. This study was performed in Thailand, where the temperature-humidity index (THI) during the experimental periods was measured to range from 78.4 to 86.1. Lactating Holstein cows classified as repeat breeders (previous artificial insemination [AI] failures) were randomly assigned into two treatments, control treatment (T1; received placebo, n = 200) and test treatment (T2; received 400 mg/h/day of beta-carotene, n = 200). All cows were subjected to a protocol for synchronization of ovulation and timed artificial insemination (TAI). The day of the 1st ovulation synchronized protocol was defined as day 0, and the total experimental period was 160 days. Daily placebo or beta-carotene supplements were given orally on day 0 and each subsequent day of the experiment. Diagnosis of pregnancy was performed using ultrasound on day 30 after insemination. Non-pregnant cows were subjected to further ovulation synchronizations (maximum of four) and TAI over a period of 160 days. Milk samples were collected every ten days throughout the experiment. The samples were analyzed for beta-carotene concentration, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. The pregnancies per AI of the cows in T2 were significantly greater than that of T1 from the 2nd to 4th TAI. During the entire experimental period, the pregnancies in T2 were significantly greater than that of T1. Cox's proportional hazards regression model data indicated a 44% greater probability of pregnancy for cows receiving beta-carotene. The concentrations of milk beta-carotene in T2 were significantly greater than T1 from the 2nd to 4th TAI. Significantly greater SOD and GPx activities were observed in T2 than T1, suggesting a reduction of oxidative stress in cows treated with beta-carotene. Dietary supplementation with beta-carotene thus improves the reproductive performance of repeat breeders exposed to heat stress, possibly by reducing oxidative stress.

El consumo semicrónico moderado de alcohol altera la foliculogénesis y la calidad núcleo-citoplasmática oocitaria, en el ratón / Moderate semi-chronic alcohol consumption alters folliculogenesis and oocyte nuclear-cytoplasmic quality in mice

Resumen El consumo crónico de alcohol es un problema de salud mundial que afecta particularmente a la población femenina. Sin embargo, los efectos de la ingesta semicrónica en cantidades moderadas a bajas en el ovario y el oocito son poco conocidos. En un modelo murino, se administró etanol al 10% en agua de bebida (hembras tratadas) o agua (hembras control) por 15 días, y luego de la superovulación o no (ovulación espontánea), se analizó el ciclo estral y la calidad ovárico-gamética. En las hembras tratadas, la frecuencia y duración del diestro aumentó, y las frecuencias de folículos y cuerpos lúteos disminuyeron vs hembras controles, valores que se restauraron luego de la superovulación. Sin embargo, en las hembras tratadas, la tasa de proliferación celular folicular y el desbalance de la expresión ovárica de VEGF (factor de crecimiento endotelial) persistieron luego de la superovulación. El número de ovocitos ovulados con metafase II anormal, fragmentados y activados partenogenéticamente fue mayor en las hembras tratadas respecto las controles. En conclusión, el consumo semicrónico moderado de alcohol produce anestro, ciclo estral irregular, foliculogénesis deficiente y anomalías núcleo-citoplasmáticas en los oocitos ovulados. Estas alteraciones podrían constituirse en un factor etiológico de pérdida gestacional temprana y desarrollo embrionario anormal luego del consumo de alcohol.

Abstract Chronic alcohol consumption is a global health problem that particularly affects the female population. However, the ef-fects of semi-chronic ethanol intake in low-moderate amounts on the ovary and oocyte are poorly understood. In a mouse model, 10% ethanol was administered in drinking water (treated females) or water (control females) for 15 days, and after superovulation or not (spontaneous ovulation), the estrous cycle and ovarian-gametic quality were analyzed. In treated females, the frequency and duration of the diestrus increased, and the frequencies of follicles and corpus luteum decreased vs control females, values that restored after superovulation. However, in treated females, the follicular cell proliferation rate and the imbalance in ovarian expression of VEGF (endothelial growth factor) persisted after superovulation. The number of ovulated oocytes with abnormal metaphase II, fragmented and parthenogenetically activated was higher in treated females than in control ones. In conclusion, moderate semi-chronic alcohol consumption produces anestrum, irregular estrous cycle, poor folliculogenesis, and nuclear-cytoplasmic abnormalities in ovulated oocytes. These alterations could constitute an etiological factor of early gestational loss and abnormal embryonic development after alcohol consumption.

Resveratrol Hinders Postovulatory Aging by Modulating Oxidative Stress in Porcine Oocytes.

Postovulatory aging of the mammalian oocytes causes deterioration of oocytes through several factors including oxidative stress. Keeping that in mind, we aimed to investigate the potential of a well-known antioxidant, resveratrol (RV), to evaluate the adverse effects of postovulatory aging in porcine oocytes. After in vitro maturation (IVM), a group of (25-30) oocytes (in three replicates) were exposed to 0, 1, 2, and 4 µmol/L of RV, respectively. The results revealed that the first polar body (PB1) extrusion rate of the oocytes significantly increased when the RV concentration reached up to 2 µmol/L (p < 0.05). Considering optimum RV concentration of 2 µmol/L, the potential of RV was evaluated in oocytes aged for 24 and 48 h. We used fluorescence microscopy to detect the relative level of reactive oxygen species (ROS), while GHS contents were measured through the enzymatic method. Our results revealed that aged groups (24 h and 48 h) treated with RV (2 µmol/L) showed higher (p < 0.05) ROS fluorescence intensity than the control group, but lower (p < 0.05) than untreated aged groups. The GSH content in untreated aged groups (24 h and 48 h) was lower (p < 0.05) than RV-treated groups, but both groups showed higher levels than the control. Similarly, the relative expression of the genes involved in antioxidant activity (CAT, GPXGSH-Px, and SOD1) in RV-treated groups was lower (p < 0.05) as compared to the control group but higher than that of untreated aged groups. Moreover, the relative mRNA expression of caspase-3 and Bax in RV-treated groups was higher (p < 0.05) than the control group but lower than untreated groups. Furthermore, the expression of Bcl-2 in the RV-treated group was significantly lower than control but higher than untreated aged groups. Taken together, our findings revealed that the RV can increase the expression of antioxidant genes by decreasing the level of ROS, and its potent antiapoptotic effects resisted against the decline in mitochondrial membrane potential in aged oocytes.

Induction of right open reading frame kinase 3 (RIOK3) during ovulation and luteinisation in rat ovary.

Atypical protein serine kinase RIOK3 is involved in cellular invasion and survival. The spatiotemporal expression pattern and regulatory mechanisms controlling expression of Riok3 were investigated in the rat ovary during the periovulatory period. Immature female rats (22-23 days old) were treated with pregnant mare's serum gonadotropin (PMSG) to stimulate follicular development, followed 48h later by injection with human chorionic gonadotrophin (hCG). Ovaries, granulosa cells, or theca-interstitial cells were collected at various times after hCG administration. Both real-time polymerase chain reaction (PCR) and in situ hybridisation analysis revealed that Riok3 was highly induced in both granulosa cells and theca-interstitial cells by hCG. Riok3 expression was induced in theca-interstitial cells at 4h after hCG. However, the expression of Riok3 mRNA was stimulated in granulosa cells at 8h. Both protein kinase C inhibitor (GF109203) and the protein kinase A inhibitor (H89) could block the stimulation of Riok3 mRNA by hCG. Furthermore, Riok3 induction is dependent on new protein synthesis. Inhibition of prostaglandin synthesis or progesterone action did not alter Riok3 mRNA expression, whereas inhibition of the epidermal growth factor (EGF) pathway downregulated Riok3 expression. In conclusion, our findings suggest that the induction of the RIOK3 may be important for ovulation and luteinisation.

Evaluation of GnRH antagonist pretreatment before ovarian stimulation in a GnRH antagonist protocol in normal ovulatory women undergoing IVF/ICSI: a randomized controlled trial.

BACKGROUND: Synchronization of follicles is key to improving ovulation stimulation with the gonadotropin-releasing hormone (GnRH) antagonist protocol. GnRH antagonist administration in the early follicular phase can quickly decrease gonadotrophin (Gn) levels and achieve downregulation before stimulation, which may improves synchronization. A previous small randomized controlled study (RCT) showed that pretreatment with a GnRH antagonist for 3 days before stimulation may increase oocyte retrieval but cannot increase the pregnancy rate. This study investigated whether the GnRH antagonist pretreatment protocol in ovulatory women can increase the synchronization of follicles and pregnancy outcomes compared with the conventional GnRH antagonist protocol. METHODS: This RCT included 136 normal ovulatory women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). Both groups were treated with recombinant follicle-stimulating hormone (r-FSH) and a flexible GnRH antagonist protocol. The women were randomized into two equal groups with or without GnRH antagonist administration from day 2 of the menstrual cycle for 3 days before stimulation. Our primary outcome was the number of retrieved oocytes. Secondary outcomes included the pregnancy rate and live birth rate. RESULTS: Both groups had similar baseline characteristics. The number of retrieved oocytes in the study group was comparable to that in the control group (9.5 [8.0-13.0] vs. 11.0 [7.0-14.8], P = 0.469). There was no significant difference in the follicle size. The fertilization rate, number of good-quality embryos, implantation rate, pregnancy rate, ongoing pregnancy rate, live birth rate per embryonic transfer cycle, and miscarriage rate were similar between the two groups. CONCLUSION: This large RCT analysed GnRH antagonist pretreatment with the GnRH antagonist protocol applied to normal ovulatory women undergoing IVF/ICSI. The number of retrieved oocytes and pregnancy outcomes did not significantly vary. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1800019730 . Registered 26 November 2018.

Transcriptional profiling of equine endometrium before, during and after capsule disintegration during normal pregnancy and after oxytocin-induced luteostasis in non-pregnant mares.

The current study used RNA sequencing to determine transcriptional profiles of equine endometrium collected 14, 22, and 28 days after ovulation from pregnant mares. In addition, the transcriptomes of endometrial samples obtained 20 days after ovulation from pregnant mares, and from non-pregnant mares which displayed and failed to display extended luteal function following the administration of oxytocin, were determined and compared in order to delineate genes whose expressions depend on the presence of the conceptus as opposed to elevated progesterone alone. A mere fifty-five transcripts were differentially expressed between samples collected from mares at Day 22 and Day 28 of pregnancy. This likely reflects the longer-term exposure to a relatively constant, progesterone-dominated environment with little change in factors secreted by the conceptus that would affect endometrial gene expression. The complement system was amongst the canonical pathways significantly enriched in transcripts differentially expressed between Day 14 and Day 22/28 of pregnancy. The expression of complement components 7 and 8 was confirmed using in situ hybridization. The expression of SERPING1, an inhibitor of the complement system, was confirmed by immunohistochemistry. In line with the resumed capacity of the endometrium to produce prostaglandin, prostaglandin G/H synthase 1 was expressed at higher levels at Days 22 and 28 than at Day 14 of pregnancy. Our data suggest that this up-regulation is enhanced by the presence of the conceptus; samples obtained from mares at Day 20 of pregnancy had significantly higher levels of prostaglandin G/H synthase 1 transcript than mares with extended luteal function.

Participation of the Cholinergic System in the Development of Polycystic Ovary Syndrome.

In rats with polycystic ovary syndrome (PCOS) induced by injection of estradiol valerate (EV), unilateral or bilateral section of the vagus nerve restores ovulatory function in 75% of animals, suggesting that the vagus nerve participates in the development of PCOS. Since the vagus nerve is a mixed nerve through which mainly cholinergic-type information passes, the objective of the present study was to analyze whether acetylcholine (ACh) is involved in the development of PCOS. Ten-day-old rats were injected with 2.0 mg EV, and at 60 days of age, they were microinjected on the day of diestrus in the bursa of the left or right ovary with 100 or 700 mg/kg of ovarian weight atropine, a blocker of muscarinic receptors, and sacrificed for histopathological examination after the surgery. Animals with PCOS microinjected with 100 mg of atropine showed a lack of ovulation, lower serum concentrations of progesterone and testosterone, and cysts. Histology of the ovaries of animals microinjected with 700 mg of atropine showed corpus luteum and follicles at different stages of development, which was accompanied by a lower concentration of progesterone and testosterone. These results allow us to suggest that in animals with PCOS, ACh, which passes through parasympathetic innervation, is an important component in the persistence and development of the pathophysiology.

Effect of exogenous administration of oxytocin on postpartum follicular dynamics, oestrous rate and ovulation in Nili-Ravi buffaloes.

Based on different surveys, dairy farmers are concerned about extensive use of exogenous oxytocin in buffaloes, which is being held responsible for reproductive problems including irregular oestrous cycle and delayed ovulation. For these concerns, effects of oxytocin injection on postpartum follicular dynamics, postpartum oestrous interval (PEI), oestrous length, the interval from onset of estrus to ovulation and blood progesterone (P4) were studied in Nili-Ravi buffaloes. For this purpose, 23 animals within 1 week after calving were randomly divided into three groups: without oxytocin (CON; n = 7), 10 i.u. oxytocin (LOW; n = 8), 30 i.u. oxytocin - (HIGH; n = 8) and used to record the PEI for the study period of 154 days. At subsequent estrus, three buffaloes from each group (not served) were selected randomly to monitor two cycles for 6 weeks. Transrectal ultrasonography was performed to evaluate follicular and corpus luteum (CL) development, and blood sampling was done for progesterone (P4) analysis. These results revealed that postpartum oestrous interval (PEI) decreased significantly in oxytocin-treated groups. The number of small, medium and total follicles on the left ovary was significantly higher in the HIGH group. However, an overall number of small and total follicles on both right and left ovaries was significantly higher in CON and HIGH groups. On the other hand, there was no difference in the number of follicles on the right ovary among all treatment groups. The same was true for the size of pre-ovulatory follicles, CL, P4 concentrations and oestrous cycle length. The intervals from onset of estrus to ovulation and from standing estrus to ovulation were increased considerably in the HIGH group. It is concluded that exogenous oxytocin administration resulted in the shortening of PEI but triggered a delay in ovulation. Moreover, a higher dose of oxytocin could stimulate the growth of small, medium, and total follicles in postpartum Nili-Ravi buffaloes.

LH Induces De Novo Cholesterol Biosynthesis via SREBP Activation in Granulosa Cells During Ovulation in Female Mice.

In the liver, the sterol response element binding protein (SREBP) and the SREBP cleavage-activated protein (SCAP) complex upregulate cholesterol biosynthesis by gene induction of de novo cholesterol synthetic enzymes (Hmgcr, Cyp51, and Dhcr7). Insulin induced gene 1 (INSIG1) negatively regulates cholesterol biosynthesis by the inhibition of de novo cholesterol biosynthetic gene expression. In the ovary, cholesterol is de novo synthesized; however, the roles of SREBP and its regulators (SCAP and INSIG1) are not well understood. In this study, when immature mice were treated with gonadotropins (eCG followed by hCG), eCG induced and hCG maintained the expression of SREBP-1a, -2, and SCAP granulosa cells, whereas INSIG1 expression was dramatically downregulated after hCG injection. Downregulation of INSIG1 led to generate the SREBPs active form and translocate the SREBPs active form to nuclei. Inhibition of generation of the SREBPs active form by fatostatin or Scap siRNA in both in vivo and in vitro significantly decreased the expressions of de novo cholesterol biosynthetic enzymes, cholesterol accumulation, and progesterone (P4) production compared with the control group. Fatostatin treatment inhibited the ovulation and increased the formation of abnormal corpus luteum which trapped the matured oocyte in the corpus luteum; however, the phenomenon was abolished by P4 administration. The results showed that decreasing INSIG1 level after hCG stimulation activated SREBP-induced de novo cholesterol biosynthesis in granulosa cells of preovulatory follicles, which is essential for P4 production and the rupture of matured oocyte during ovulation process.

Berberine improves ovulation and endometrial receptivity in polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a clinical syndrome with reproductive and endocrine disorders. Berberine is a monomer from Chinese herbs such as Coptis chinensis, whose effect on improving ovulation and endometrial receptivity of PCOS is uncertain. PURPOSE: To evaluate the effect of berberine on improving PCOS and explore the mechanism. METHODS: The rat model of PCOS was induced by intraperitoneal injection of testosterone propionate. Then they was divided into model (Mod) group, low-dose of berberine (BL) group, high-dose of berberine (BH) group and metformin (Met) group as well as a control (Con) group was established. Ovary morphology, hormone level, glucolipid metabolism were measured. UID-mRNA-seq of ovary tissue was conducted to seek the mechanism of berberine on improving ovulation. Three biomarkers of endometrial receptivity were also examined in endometrium by immunohistochemistry. RESULTS: The number of cystic follicles was increased while the number of corpus luteum was decreased in the rats of Mod group. These changes could be reversed by high-dose of berberine intervention. Berberine could also decrease the levels of serum luteinizing hormone (LH) and total cholesterol (TC) in PCOS rats. Meanwhile, berberine improved the impairment of abnormal oral glucose tolerance without affecting fasting insulin level and Homeostasis model assessment-insulin resistance (HOMA-IR). Luteinizing hormone/ choriogonadotropin receptor (LHCGR) and cytochrome P450 Family 19 Subfamily A Member 1 (CYP19A1) were focused via RNA-seq of ovary. Protein expression in ovary and mRNA expression in granulosa cell of LHCGR and CYP19A1 were decreased in Mod group and rescued by the intervention of berberine. A decrease of endometrial thickness and an increase of integrin αvß3 and lysophosphatidic acid receptor 3 (LPAR3) protein expression were observed in Mod group, which could be also reversed by berberbine. CONCLUSIONS: Berberine could improve ovulation in PCOS and the mechanism might be associated with up-regulating LHCGR and CYP19A1. Berberine could also improve endometrial receptivity through down-regualting αvß3 and LPAR3.

Dulaglutide, a long-acting GLP-1 receptor agonist, can improve hyperandrogenemia and ovarian function in DHEA-induced PCOS rats.

OBJECTIVE: The purpose of this study was to explore the effect of dulaglutide on DHEA induced PCOS rats and its mechanism, to provide new drugs and research directions for clinical treatment of PCOS. METHODS: In this study, the PCOS model was established by giving female SD rats subcutaneous injection of DHEA for 21 consecutive days. After modeling, the treatment group was injected subcutaneously with three doses of dulaglutide for 3 weeks. The model group was injected with sterile ultrapure water, and the normal group did not get any intervention. The body weight changes of rats in each group were recorded from the first day when rats received the administration of dulaglutide. Three weeks later, the rats were fasted the night after the last treatment, determined fasting insulin and fasting glucose the next day. After the rats were anesthetized by chloral hydrate, more blood was collected from the heart of the rat. The serum insulin, testosterone and sex hormone binding globulin (SHBG) levels were detected by the enzyme-linked immunoassay method. After removing the adipose tissue, the obtained rat ovary tissue was used for subsequent experimental detection, using HE staining for morphology and follicular development analysis; qRT-PCR for the detection of 3ßHSD, CYP17α1, CYP19α1, and StAR gene expression in ovarian tissue; and western blotting analysis of CYP17α1, CYP19α1, StAR protein expression and insulin level to verify whether dulaglutide has a therapeutic effect on PCOS in rats. RESULTS: After treated with different concentrations of dulaglutide, we found that the body weight of rats in the treatment groups were reduced. Compared with the rats in PCOS group, the serum androgen level of rats in the treatment groups was significantly decreased, and the serum sex hormone binding protein content was significantly increased, and there was statistically significant difference between these groups and PCOS group. In terms of protein expression and gene regulation, the expression of 3ßHSD, CYP19α1 and StAR in the ovarian tissue of rats in treatment groups were decreased significantly after received the treatment of dulaglutide, and there was statistically significant difference between these groups and PCOS group. In addition, dulaglutide reduced the insulin content in the ovarian tissue of PCOS rats. CONCLUSION: Dulaglutide may reduce the hyperandrogenemia of PCOS rats by regulating the content of serum SHBG and the expression of 3ßHSD, CYP19α1, and StAR related genes and proteins, thereby inhibiting the excessive development of small follicles and the formation of cystic follicles in the ovaries of PCOS rats, thereby improving polycystic ovary in PCOS rats. In addition, dulaglutide may reduce the weight of PCOS rats, further reducing the level of high androgen in PCOS rats, and improving the morphology of their polycystic ovaries.

How far is too far? Does time interval between GnRH antagonist and GnRH agonist trigger in GnRH antagonist cycles matter?

RESEARCH QUESTION: What is a suitable time interval between the last GnRH antagonist exposure and GnRH agonist (GnRHa) triggering for final follicular maturation? DESIGN: A retrospective cohort study including 413 patients undergoing GnRH antagonist cycles in which GnRHa trigger was used, either solely or as a dual trigger. The primary outcome measure was the follicle/mature oocyte ratio. Cycles were analysed according to the time interval between the last GnRH antagonist exposure and the GnRHa triggering: Group 1 included patients with a 12-14 h interval; Group 2: 7-10 h interval; Group 3: 5-6 h interval and Group 4: 2-4 h interval. LH concentration was measured 11-13 h post-GnRHa injection. RESULTS: Median LH value was 65 IU/l. There was a weak but significant correlation between basal LH and the LH surge (R2 = 0.137, P < 0.001). Although square root LH values differed significantly between study groups (P < 0.001; higher in Groups 2 and 3), the follicle/mature oocyte ratio was not different across the four antagonist-agonist interval groups and no correlation was detected between the post-trigger LH concentration and the follicle/oocyte ratio (R2 = 0.011). In a model integrating age, day 3 FSH concentration, maximal oestradiol and body mass index along with the study groups, none of these factors was significantly related to the follicle/mature oocyte outcome ratio. Insufficient surge (LH < 15 IU/l) occurred in 14 (3.4%) cases. Rates of insufficient LH surge did not differ significantly between the groups (2.4%, 3.2%, 3.4% and 7.1% in Groups 1 to 4, respectively; P = 0.5). CONCLUSIONS: LH concentrations post-GnRHa trigger differ in regard to antagonist-agonist intervals, but the follicle/mature oocyte ratio achieved was not affected.