Ovulation Rate Research Articles

Connectedness between Intensive and Extensive Ruminant Production Systems: Using Dairy Cow Feed Leftovers to Generate Out-of-Season Bio-Economic Indices in Goats

Founded on a circular economy perspective, the possible effect of targeted supplementation with leftover feed from dairy cows (i.e., intensive system) upon the productive economic performance of crossbred–rangeland goats (i.e., extensive system) in northern arid Mexico was assessed. Multiparous goats (n = 38) with similar body condition score (BCS) and body weight (BW) were randomly assigned during the deep anestrus season (i.e., March–April, 25° N) into two groups: (1) the control-non-supplemented group (CONT; n = 19; BCS: 1.76 ± 0.06; BW: 44.3 ± 2.5 kg) and (2) the supplemented group (SUPL; n = 19; BCS: 1.76 ± 0.07; BW: 43.7 ± 1.8 kg). While the SUPL group received 400 g goat d−1 of dairy cow feed leftovers prior to grazing, both groups went daily to the rangeland (i.e., ≈8 h). The study considered an experimental period of 36 d with an experimental breeding of 11 d (d0–d10). Previously, on days −20, −10, −1 preceding the male-to-female interaction, the anovulatory status of goats was confirmed through ultrasonographic scanning. Prior to mating, the males were separated from goats and treated for a period of 3 weeks (i.e., every 3rd d) with testosterone (i.e., 50 mg i.m.). The response variables evaluated considered goats induced to estrus (GIE, %), goats ovulating (GO, %), ovulation rate (OR, units), pregnancy rate-1 (PRd36, %), pregnancy rate-2 (PRd50, %), embryo mortality-d50 (EMO, %), potential kidding index-d50 (PKId50,%), kid weight at birth simples (KWBS, kg), potential litter efficiency at birth (PLEB, kg), and potential litter efficiency at weaning (i.e., d21 post kidding), either expressed as kg head−1 (PLEW1) or USD head−1 (PLEW2). Although no differences (p > 0.05) occurred for GIE and PRd50, increases in the phenotypic expression of OR (1.42 vs. 0.73), PRd36 (68.4 vs. 36.8), EMO (23.0 vs. 0), PKId50 (74.7 vs. 26.8), and KWBS (4.1 vs. 3.3) occurred (p < 0.05) in the SUPL goats. To have a more integrative evaluation regarding the out-of-season reproductive outcomes, three bio-economic efficiency indices per goat exposed to males were generated: PLEB (4.3 vs. 0.6 kg), PLEW1-kg (7.7 vs. 3.1 kg), and PLEW2-USD (63.9 vs. 26.1 USD), which also favored (p < 0.05) to the SUPL goats. The last result occurred despite no differences (p > 0.05) regarding BW, BCS, and serum glucose concentrations between experimental groups. Furthermore, applying the main research outcomes from this specific study toward the large-scale goat production system in the Comarca Lagunera—one of the largest dairy goat production hubs in The Americas—denoted promising expectations, either from an economic or productive–reproductive standpoint. Certainly, goat producers from the region would increase their potential annual income just from the sale of kids by close to 250%; that is from MUSD 1.1 to 3.9. This result should reduce food insecurity and economic stress, as well as enhance the livelihoods of the goat keepers and their families.

Molecular Action of Tamoxifen in the Ovaries of Rats with Mammary Neoplasia

Tamoxifen (TAM) is a drug commonly used in patients with breast cancer. The anticancer effect of TAM occurs via its ability to antagonize estrogen-dependent growth of mammary epithelial cells. Previously, we demonstrated that TAM prevented the chemotherapy-induced loss of ovarian follicular reserves in both cancer-free rats and rats with cancer. Such follicular loss is a main cause of infertility in young women treated for cancer. The current study was undertaken to discover the molecules and intracellular pathways involved in the action of TAM in the ovaries of rats with mammary tumors. To meet this goal we used transcriptomic (RNA-Seq) and proteomic (2D-DIGE/MS) approaches. TAM inhibited the expression of genes and lncRNAs involved in ovarian steroidogenesis. Moreover, TAM altered the expression of genes related to primordial follicle activation or arrest. In addition, proteomic screening indicated the importance of basic metabolic processes in the ovarian actions of TAM. Although simple extrapolation of these data to humans is not possible, the results of this study emphasize the need to explore the ability of TAM to affect ovarian function in women undergoing cancer treatment.

224 Average Daily Feed Intake in Previous Lactations is Associated with Subsequent Reproductive Performance in Sows

Abstract The objective of this study was to investigate the influence of average daily feed intake (ADFI) in previous lactations on subsequent reproductive performance in multiparous sows. Data for this study were collected from 2017 to 2022 at Grangenia, a 2,800 L03 PIC sows farrow-to-wean commercial multiplier from Grupo Kerbest and integrated with Grupo UVESA. The farm is located in Ávila, Spain. In total, data on ADFI during lactation and litter size traits were available for 10,425 sows. Born alive (BA), stillborn (SB) and mummified (MM) piglets were expressed both as total numbers and as percentage from total born (TB) piglets. Sow parity was classified as parity 2, 3, 4 and 5+. Data were analyzed using linear mixed models in R v4.1.2. For all traits, initial models included ADFI for the immediate previous parity as a linear and quadratic predictor. ADFI ranged from 1.3 to 9.6 kg/day. Linear mixed models revealed that ADFI in the previous lactation had a positive linear association (P < 0.001, Table 1) with all studied traits except with BA % and SB % where a quadratic association (P < 0.001) was also observed (quadratic slope = 0.018 ± 0.0044 and - 0.016 ± 0.0051, respectively). Results indicate that on average, sows in the lower ADFI limit would have 2.1 TB, 1.6 BA, 0.13 SB and 0.16 MM less when compared with sows in the upper ADFI limit across all parities. The BA % decreased and SB% increased when ADFI in the previous parity was between 4.5 and 6 kg across all parities. Under the conditions of this study, increasing ADFI in the previous lactation improved subsequent reproductive performance across all parities. It is likely that this effect was at least partly mediated through the greater number of follicles with optimal preovulatory size, luteinizing hormone secretion, ovulation rates, and embryo mortality, although this requires further investigation. A limitation of this study was that it was not possible to elucidate if the observed effect of ADFI in the previous parity was mediated through greater amino acid and/or energy intake due to the observational nature of this study. Nonetheless, our results highlight the importance of optimal sow nutritional management during the lactation period for improved lifetime reproductive performance.

Effect of Clomiphene Citrate on Estrus Cycle and The Ova Shed in the Ovary of Female Sprague Dawley Rats

Purpose: Clomiphene citrate (CC) is used in the management of infertile females. Estrus Cycle indices are good parameters for evaluating reproductive changes, while actual ova shed represents evidence of ovulation. This study is aimed at investigating how different doses of CC can affect the Estrus Cycle (EC), Estrus Cycle Ratio, (ECR), and ova shed (OS) in adult female rats. 
 Methodology: Twenty-five (50) female Sprague Dawley (SD) rats were divided into 5 groups. Group A was controlled while groups B, C, D, and E were treated groups. Group A received 0.5 ml of sterile water. Groups B, C, and D were given 0.2 mg/kg, 2 mg/kg, and 4 mg/kg respectively at diestrus. Group E was given 6mg/kg/day of CC dissolved in sterile water. The administration was done orally. A vaginal smear was evaluated for various estrus phases. ECR was calculated, and ova shed at the estrus phase was evaluated at autopsy. All data were presented as mean ± standard error of the mean (SEM). Statistical significance was taken at P < 0.05
 Findings: There was a significant decrease (p<0.05) in the number of proestrus, estrus, metestrus, and diestrus in treated groups compared with control. ECR value in all treated groups also decreased significantly (p<0.05) when compared with control. This study further shows that all the animal groups (A-E) released ova but there was a significant decrease (p<0.05) in the number of ova released in groups B, C, D, and E against the control group.
 Conclusion: CC decreases EC. It reduced ECR, hence prolonging luteogenesis. It decreases the number of eggs released. With a large dose and prolonged use, eggs were still released even when the ova released and counted were fewer compared with when this drug was not in use. 
 Recommendation: Infertile couples should copulate more at the luteal phase of the menstrual cycle when on CC to increase their chances of pregnancy. CC decreases the number of eggs released but makes the few eggs released stay longer for fertilization.

Efficacy of Letrozole vs Clomiphene Citrate for induction of ovulation in women with polycystic ovarian syndrome.

To compare the efficacy of letrozole vs Clomiphene citrate for ovulation induction in PCOS women. This double blind randomized controlled trial was conducted at Services Hospital, Lahore, from January 2016 to December 2020. Total 220 patients, diagnosed with PCOS according to Rotterdam criteria were randomly assigned into two groups after taking informed consent. The women were followed for ovulation, pregnancy and live birth rates in the next five consecutive menstrual cycles with either clomiphene citrate or letrozole. Letrozole had significantly better pregnancy rate (29.0% vs 15.4% p-value 0.015), monofollicular development (77.2% vs 52.7% p-value 0.000) and live birth rate (25.4% vs 10.9% p-value 0.005) as compared to clomiphene citrate. There was no difference between the two groups in ovulation rate (68.1% vs 63.6%, p-value 0.477), early pregnancy loss (3.6% vs 4.5% p-value 0.734), and twin pregnancy (0.0% vs 1.81% p-value 0.155). There was no ectopic pregnancy and no congenital anomalies in both groups. Hot flushes were higher in clomiphene group (31.8% vs 12.7% p-value 0.001) while fatigue (30.9% vs 8.1% p-value 0.000) and dizziness (21.8% vs 10.0% p-value 0.029) was higher with letrozole but these were well tolerated. Letrozole is better treatment choice than clomiphene citrate in PCOS women with infertility in terms of pregnancy and live birth rate.ClinicalTrials.gov Identifier: NCT05702957.

The utilization of ultrasonography for the assessment of infertility factors and the comparative efficacy of in vitro fertilization

Background/AimAlongside anxiety and melancholy, infertility has been one of the most significant social and psychological issues among Middle Eastern individuals of both sexes. This study aimed to investigate the utilization of ultrasonography for the assessment of infertility factors and the comparative efficacy of in vitro fertilization (IVF) among women in Sudan. MethodsA retrospective analysis of 125 infertile women who visited the Khartoum Fertility Center in Sudan from 2018 to 2019. Using ultrasound scanning with 3.5 MHz and 7–10 MHz instruments, the infertility factors, age groups, ovulation, embryo transfer (ET), pregnancy, and fetal weight of each woman were determined. The data was analyzed using Statistical Package for the Social Sciences (SPSS) version 20.0 for Microsoft Windows. ResultsThe most prevalent infertility factors among Sudanese women, according to the study, are the uterine factor (29.6%), Tubule's illness (15.2%), multiple factors (20%), and male factors (20.8%). There were three age categories with successful ET: 28–30 (85.4%), 31–33 (74.3%), and 34–36 (60.9%). The respective frequencies of successful pregnancy were (28–30; 56.8%) and (31–33; 50.8%). ConclusionUterine anomalies, tubal diseases, and male issues are the main causes of infertility in Sudan. Successful ovulation rates are highest in the 28–30, 31–33, and 34–36 age groups, at 97.4%, 87.5%, and 80%, respectively. Successful ET rates were 85.4% and 74.3% for 28–30 and 31–33-year-olds, respectively. The 56.8% and 50.8% pregnancy rates in these age groups were similarly respectable. At 34 weeks, the IVF-obtained fetal weight is significantly different from the usual weight (p = 0.01).

Production of marmoset eggs and embryos from xenotransplanted ovary tissues

The common marmoset (Callithrix jacchus) has attracted attention as a valuable primate model for the analysis of human diseases. Despite the potential for primate genetic modification, however, its widespread lab usage has been limited due to the requirement for a large number of eggs. To make up for traditional oocyte retrieval methods such as hormone administration and surgical techniques, we carried out an alternative approach by utilizing ovarian tissue from deceased marmosets that had been disposed of. This ovarian tissue contains oocytes and can be used as a valuable source of follicles and oocytes. In this approach, the ovarian tissue sections were transplanted under the renal capsules of immunodeficient mice first. Subsequent steps consist of development of follicles by hormone administrations, induction of oocyte maturation and fertilization, and culture of the embryo. This method was first established with rat ovaries, then applied to marmoset ovaries, ultimately resulting in the successful acquisition of the late-stage marmoset embryos. This approach has the potential to contribute to advancements in genetic modification research and disease modeling through the use of primate models, promoting biotechnology with non-human primates and the 3Rs principle in animal experimentation.

Development of an acute ovine model of polycystic ovaries to assess the effect of ovarian denervation.

Polycystic ovary syndrome (PCOS) seems to be associated with increased ovarian sympathetic nerve activity and in rodent models of PCOS reducing the sympathetic drive to the ovary, through denervation or neuromodulation, improves ovulation rate. We hypothesised that sympathetic nerves work with gonadotropins to promote development and survival of small antral follicles to develop a polycystic ovary phenotype. Using a clinically realistic ovine model we showed a rich sympathetic innervation to the normal ovary and reinnervation after ovarian transplantation. Using needlepoint diathermy to the nerve plexus in the ovarian vascular pedicle we were able to denervate the ovary resulting in reduced intraovarian noradrenaline and tyrosine hydroxylase immunostained sympathetic nerves. We developed an acute polycystic ovary (PCO) model using gonadotrophin releasing hormone (GnRH) agonist followed infusion of follicle stimulating hormone (FSH) with increased pulsatile luteinising hormone (LH). This resulted in increased numbers of smaller antral follicles in the ovary when compared to FSH infusion suggesting a polycystic ovary. Denervation had no effect of the survival or numbers of follicles in the acute PCO model and did not impact on ovulation, follicular and luteal hormone profiles in a normal cycle. Although the ovary is richly inervated we did not find evidence for a role of sympathetic nerves in ovarian function or small follicle growth and survival.

Effects of different cryopreservation methods on canine isolated preantral follicles

The aim of the present study was to compare the survival and developmental rate of canine isolated preantral follicles (PAFs) after cryopreservation with different methods (closed vs open vitrification). Follicles were isolated from ovaries randomly divided into three groups: fresh control, OPS (open pulled straw) vitrified and cryotube (CT) vitrified. Post-thaw viability of follicles and oocytes was assessed. Fresh and vitrified/thawed PAFs were cultured in 20 µl drops of FSH-supplemented medium for 10 days. Follicular growth, survival rate, estradiol production and ovulation rate were examined. CT method resulted in lower rate of live cells (58.7%) and oocytes (38.8%) than that of fresh ones (83.6% and 64%, respectively) and OPS (80.3% and 79.3%, respectively). Survival rate was similar to fresh follicles in OPS group (98.5% and 95.4%, respectively), while CT decreased the survival to 81.2%. Fresh follicles showed continuous growth, while CT follicles stopped to increase their size after 2 day. In the OPS vitrified follicles, this halting occurred between Day5 and Day10. Fresh follicles showed the highest estradiol production (range: 26.9 – 266.2 pg/ml). Comparing the two vitrified groups, lower estradiol concentration range was measured in the CT group (7.8–48.7 pg/ml vs. 15.4–89.6 pg/ml). Ovulation rate in each group was lowest in the OPS group (1.7% vs 7% and 8.9% in fesh and CT, respectively). Our data show that OPS vitrification provides superior survival rate, in vitro growth and hormonal production to CT. To our knowledge, these are the first results on comparing different cryopreservation protocols on canine isolated preantral follicles.

Effect of indomethacin on embryo implantation and histomorphology of uterus, ovary, kidney, and liver of rats

BackgroundThis study aimed to determine the effects of Indomethacin (IMC) treatment on embryo implantation and histomorphology of uterus, ovary, and other vital organs and its effective dosage in establishing embryo implantation dysfunction model in Sprague-Dawley (SD) rats. Materials and MethodsThe experiments were performed on 24 (6 × 4 groups) adult female SD rats aged 12 weeks old. G1 was the control group and received a normal diet with normal saline. However, on pregnancy days 3 (Pd3) and 4 (Pd4), G2, G3, and G4 were given normal saline and subcutaneously administered IMC twice daily at different doses of 4.33, 4.66 and 5.00 mg/kg body weight, respectively. The rats were euthanized on day 8 of pregnancy (Pd8). The uterus was excised and examined for signs of pregnancy, followed by tissue samples from liver, kidney, and ovary (for histomorphological examination using haematoxylin and eosin stain). ResultsAll IMC treatment doses disrupted the implantation process and caused a significant reduction in embryo development. Analysis for histopathological changes revealed that IMC doses above 4.33 mg/kg body weight caused more adverse reproductive health effects in rats. Vasoconstriction and micro vascularization were detected in the liver, while degenerative Bowman's capsules and inflammatory cells were observed in kidney sections from IMC-treated rats. ConclusionIMC therapy interfered with implantation and embryo development in rats, resulting in significant uterine vasoconstriction and atrophy, 4.33 mg/kg bwt dose appeared to be optimum to establish embryo implantation dysfunction in SD rats.

Intergenerational Hyperglycemia Impairs Mitochondrial Function and Follicular Development and Causes Oxidative Stress in Rat Ovaries Independent of the Consumption of a High-Fat Diet.

We analyzed the influence of maternal hyperglycemia and the post-weaning consumption of a high-fat diet on the mitochondrial function and ovarian development of the adult pups of diabetic rats. Female rats received citrate buffer (Control-C) or Streptozotocin (for diabetes induction-D) on postnatal day 5. These adult rats were mated to obtain female pups (O) from control dams (OC) or from diabetic dams (OD), and they received a standard diet (SD) or high-fat diet (HFD) from weaning to adulthood and were distributed into OC/SD, OC/HFD, OD/SD, and OD/HFD. In adulthood, the OGTT and AUC were performed. These rats were anesthetized and euthanized for sample collection. A high percentage of diabetic rats were found to be in the OD/HFD group (OD/HFD 40% vs. OC/SD 0% p < 0.05). Progesterone concentrations were lower in the experimental groups (OC/HFD 0.40 ± 0.04; OD/SD 0.30 ± 0.03; OD/HFD 0.24 ± 0.04 vs. OC/SD 0.45 ± 0.03 p < 0.0001). There was a lower expression of MFF (OD/SD 0.34 ± 0.33; OD/HFD 0.29 ± 0.2 vs. OC/SD 1.0 ± 0.41 p = 0.0015) and MFN2 in the OD/SD and OD/HFD groups (OD/SD 0.41 ± 0.21; OD/HFD 0.77 ± 0.18 vs. OC/SD 1.0 ± 0.45 p = 0.0037). The number of follicles was lower in the OD/SD and OD/HFD groups. A lower staining intensity for SOD and Catalase and higher staining intensity for MDA were found in ovarian cells in the OC/HFD, OD/SD, and OD/HFD groups. Fetal programming was responsible for mitochondrial dysfunction, ovarian reserve loss, and oxidative stress; the association of maternal diabetes with an HFD was responsible for the higher occurrence of diabetes in female adult pups.

Control Phytophagous Nematodes By Engineering Phytosterol Dealkylation Caenorhabditis elegans as a Model.

Plant-parasitic nematodes ingest and convert host phytosterols via dealkylation to cholesterol for both structural and hormonal requirements. The insect 24-dehydrocholesterol reductase (DHCR24) was shown in vitro as a committed enzyme in the dealkylation via chemical blocking. However, an increased brood size and ovulation rate, instead compromised development, were observed in the engineered nematode Caenorhabditis elegans where the DHCR24 gene was knocked down, indicating the relationship between DHCR24 and dealkylation and their function in nematodes remains illusive. In this study, a defect in C. elegans DHCR24 causes impaired growth of the nematode with sitosterol (a major component of phytosterols) as a sole sterol source. Plant sterols with rationally designed structure (null substrates for dealkylation) can't be converted to cholesterol in wild-type worms, and their development was completely halted. This study underpins the essential function of DHCR24 in nematodes and would be beneficial for the development of novel nematocidal strategies.

Chronic Fluoride Exposure Induces Ovarian Dysfunction and Potential Association with Premature Ovarian Failure in Female Rats.

Chronic fluorosis has been widely investigated for its adverse effects on skeletal and neurological health; however, its impact on reproductive health, especially in females, remains underexplored. In this study, female Sprague-Dawley rats were exposed to different fluoride concentrations (0.75, 50, and 100mg/L) in their drinking water for six months. Dental fluorosis and increased urinary fluoride content were observed in fluoride-exposed rats, reflecting fluoride accumulation and exposure levels. Chronic fluorosis resulted in reduced ovary organ coefficient, indicating harmful effects on ovarian tissue. Additionally, the number of ovarian primordial and primary/secondary follicles decreased, while the number of atresia follicles increased. Furthermore, chronic fluorosis led to disrupted estrous cycles. Hormonal analysis revealed altered secretion of estrogen, progesterone, anti-Müllerian hormone, luteinizing hormone, follicular stimulating hormone, and inhibin B in response to fluoride exposure. Ultrastructural observation of ovarian granulosa cells showed evidence of apoptosis, which was further confirmed by flow cytometry. Caspase-3 activity was increased, and ATP levels were decreased, suggesting mitochondrial impairment and apoptosis induction. The mRNA and protein expression of BMP15 and GDF9, essential regulators of ovarian function, significantly decreased with increasing fluoride concentration. Furthermore, gene expression analysis identified a panel of premature ovarian failure-related genes that were downregulated in fluoride-exposed rat ovaries. These findings suggest that chronic fluoride exposure may contribute to ovarian dysfunction and possibly the pathogenesis of premature ovarian failure. Understanding the toxicological effects of chronic fluoride exposure on ovarian function is essential for identifying potential environmental risk factors affecting female reproductive health.

Unilateral lesion of the suprachiasmatic nucleus impairs estradiol feedback, follicular development, estrous cycle and ovulation.

Ovulation is timed by neural signals originating at the suprachiasmatic nucleus (SCN) that trigger ovulation when converge with high estradiol levels, which indicates the maturation of ovarian follicles. We have shown that the hypothalamic regulation of ovulation is asymmetrical and we hypothesized that the paired SCN could contribute to such symmetries. We unilaterally lesioned the SCN of rats at each stage of the estrous cycle and evaluated the acute effects on the progression of their estrous cycle, follicular development and ovulation. Lesions disrupted the estrous cycle when performed in estrus/metestrus but not in diestrus/proestrus. Abnormalities in follicular development were observed in the non-ovulating lesioned rats and this was independent of the side of the SCN destroyed and the stage of the cycle when surgery was performed. Groups of lesioned rats were then hormonally primed with GnRH or estradiol to assess the neuroendocrine pathway altered by the treatment. GnRH restored ovulation, suggesting that both SCN are needed for proper triggering of the preovulatory surge of GnRH and that unilateral lesion does not impair the sensitivity of the pituitary or the ovary to GnRH and gonadotropins, respectively. Estradiol was asymmetrically effective to restore ovulation in rats lesioned in estrous, partially effective on rats operated at diestrus and ineffective on metestrus. Our results indicate that the SCN regulates the activity of the hypothalamic-pituitary-ovarian axis not only by modulating the preovulatory surge of GnRH/gonadotropins, but also by promoting the hypothalamic integration of estrogenic signals from the ovaries in an asymmetric and stage-dependent fashion.

Xrcc5/KU80 is not required for the survival or activation of prophase-arrested oocytes in primordial follicles.

The non-growing, meiotically-arrested oocytes housed within primordial follicles are exquisitely sensitive to genotoxic insults from endogenous and exogenous sources. Even a single DNA double-strand break (DSB) can trigger oocyte apoptosis, which can lead to accelerated depletion of the ovarian reserve, early loss of fertility and menopause. Therefore, repair of DNA damage is important for preserving the quality of oocytes to sustain fertility across the reproductive lifespan. This study aimed to evaluate the role of KU80 (encoded by the XRCC5 gene) - an essential component of the non-homologous end joining (NHEJ) pathway - in the repair of oocyte DNA DSBs during reproductive ageing, and following insult caused by the DNA-damaging chemotherapies cyclophosphamide and cisplatin. To investigate the importance of KU80 following endogenous and exogenous DNA damage, ovaries from conditional oocyte-specific Xrcc5 knockout (Xrcc5 cKO) and wildtype (WT) mice that were aged or exposed to DNA damage-inducing chemotherapy were compared. Ovarian follicles and oocytes were quantified, morphologically assessed and analysed via immunohistochemistry for markers of DNA damage and apoptosis. In addition, chemotherapy exposed mice were superovulated, and the numbers and quality of mature metaphase- II (MII) oocytes were assessed. The number of healthy follicles, atretic (dying) follicles, and corpora lutea were similar in Xrcc5 cKO and WT mice at PN50, PN200 and PN300. Additionally, primordial follicle number and ovulation rates were similar in young adult Xrcc5 cKO and WT mice following treatment with cyclophosphamide (75mg/kg), cisplatin (4mg/kg), or vehicle control (saline). Furthermore, KU80 was not essential for the repair of exogenously induced DNA damage in primordial follicle oocytes. These data indicate that KU80 is not required for maintenance of the ovarian reserve, follicle development, or ovulation during maternal ageing. Similarly, this study also indicates that KU80 is not required for the repair of exogenously induced DSBs in the prophase-arrested oocytes of primordial follicles.

Ovarian toxicity of e-cigarette liquids: Effects of components and high and low nicotine concentration e-cigarette liquid in vitro.

Electronic cigarette use has become increasingly popular, with potential consequences for reproductive health. We aimed to investigate the effects of different components of e-liquid on the ovary and compare the impact of low nicotine concentration e-liquids (LN e-liquids) and high nicotine concentration e-liquids (HN e-liquids) on ovarian toxicity. A total of 378 rat ovaries were divided into seven groups, including control (no intervention), nicotine (0.05 mg/mL), flavoring (0.25 μL/mL), propylene glycol (PG) (2.5 μL/mL), vegetable glycerin (VG) (2.0 μL/mL), LN e-liquid (0.05 mg nicotine + 0.25 μL flavoring + 2.5 μL PG + 2.0 μL VG + 0.25 μL distilled water/mL medium) and HN e-liquid groups (0.05 mg nicotine + 0.05 μL flavoring + 0.5 μL PG + 0.4 μL VG + 0.05 μL distilled water/mL medium). After three hours of in vitro culture, ovarian morphology, oxidation levels [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA)], and apoptosis levels [factor related apoptosis (Fas), Cyt-c, Caspase-9, Caspase-3] were analyzed. Our findings indicate that nicotine has limited impact on the ovary, while flavoring, PG, and VG all cause ovarian damage including morphological damage, disruption of oxidative balance and promotion of apoptosis, with VG having the most significant effect. Moreover, LN e-liquids may lead to more severe ovarian damage than HN e-liquids at an equal intake of total nicotine. Our study highlights that in e-liquid formula, nicotine has a limited effect on the ovaries, but flavoring, PG, and VG all cause damage to the ovaries, with VG the most damaging. At a consistent level of total nicotine intake, e-liquids with low nicotine concentrations cause more damage to the ovaries than those with high nicotine concentrations. These findings contribute to a better understanding of the impact of e-liquids on ovarian health and have important implications for public health policy.

TGF-β1 and TGF-β3, but not TGF-β2, are upregulated in the ovaries of ovarian hyperstimulation syndrome†.

Ovarian hyperstimulation syndrome (OHSS) is a life-threatening and potentially fatal complication during in vitro fertilization treatment. The levels of transforming growth factor-β1 (TGF-β1) are upregulated in human follicular fluid and granulosa-lutein cells (hGL) of OHSS patients and could contribute to the development of OHSS by downregulating steroidogenic acute regulatory protein (StAR) expression. However, whether the same is true for the other two members of the TGF-β family, TGF-β2 and -β3, remains unknown. We showed that all three TGF-β isoforms were expressed in human follicular fluid. In comparison, TGF-β1 was expressed at the highest level, followed by TGF-β2 and TGF-β3. Compared to non-OHSS patients, follicular fluid levels of TGF-β1 and TGF-β3 were significantly upregulated in OHSS patients. The same results were observed in mRNA levels of TGF-β isoforms in hGL cells and ovaries of OHSS rats. In addition, StAR mRNA levels were upregulated in hGL cells of OHSS patients and the ovaries of OHSS rats. Treatment cells with TGF-β isoforms downregulated the StAR expression with a comparable effect. Moreover, activations of SMAD3 signaling were required for TGF-β isoforms-induced downregulation of StAR expression. This study indicates that follicular fluid TGF-β1 and TGF-β3 levels could be used as biomarkers and therapeutic targets for the OHSS.

FRI376 Regulation Of Theca Cell Function By Salt-Inducible Kinases

Abstract Disclosure: M. Rodriguez Esquivel: None. E. Hayes: None. O. Lakomy: None. M. Hassan: None. R. Filzen: None. C.O. Stocco: Grant Recipient; Self; NIH R01HD097202. The most common identifiable factors of female infertility are ovulatory disorders. Ovulation is the pinnacle of folliculogenesis, a process that requires an interplay between the oocyte, the granulosa cells, and the theca cells (TCs). TCs are the only source of ovarian androgens. Androgens play vital roles in female fertility acting as substrates for estrogen production in granulosa cells and directly regulating ovarian function via the activation of the androgen receptor. However, abnormally elevated androgen levels reduce fertility in humans and animals, suggesting that a delicate equilibrium exists between the beneficial and harmful effects of androgens in the ovary. Therefore, uncovering novel mechanisms regulating androgen synthesis in TCs is of great significance. The capacity of TCs to synthesize androgens relies on the expression of the rate-limiting enzyme CYP17A1, which converts progestogens into androgens, and its stimulation by the luteinizing hormone (LH). Previously, our group showed that salt-inducible kinases (SIKs) regulate granulosa cell steroidogenesis. Here, we investigated whether SIKs play any role in the regulation of androgen production in TCs. SIK2 and SIK3 were detected by IHC in the TCs of rat ovaries. Western blot confirmed this finding using isolated rat TCs. Next, rat TCs in culture were treated with LH in the presence or absence of HG, a highly specific SIK inhibitor. SIK inhibition enhanced the stimulatory effect of LH on Cyp17a1 mRNA expression. HG alone also increased Cyp17a1 expression to levels higher than those found in the presence of LH. Similarly, HG alone increased testosterone and potentiated LH stimulation of testosterone production. SIK inhibition also enhanced the stimulatory effect of LH on the expression of StAR and Cyp11a1. Concentration-response experiments for the SIK inhibitor in the presence or absence of LH show that SIK inhibition stimulates Cyp17a1 in a concentration-dependent manner from 0.1 to 1 µM. Of note, at 3 µM, HG was less effective in inducing Cyp17a1 than at 1 µM, suggesting that higher concentrations of HG may have alternative unknown effects. Activation of adenyl cyclase with forskolin or emulation of increased intracellular cAMP with dbcAMP stimulated Cyp17a1 an effect that was also enhanced by the inhibition of SIK. Since the main target of cAMP is PKA, we used lentivirus to express constitutively active PKA (caPKA). Overexpression of caPKA was sufficient to stimulate testosterone production, an effect that was significantly augmented by SIK inhibition, suggesting that SIKs regulate factors downstream of PKA. This evidence shows that TCs express SIKs and reveal novel roles for SIKs in the regulation of TC function and androgen production. This information could contribute to uncovering therapeutic targets to treat hyperandrogenic diseases such as PCOS. Presentation: Friday, June 16, 2023

Protective Effects of Ginger Extract on Oxidative Stress and Steroidogenesis-related Genes in The Ovary of Streptozotocin-induced Diabetic Rats

Background and Aims: Ginger has anti-oxidant and anti-diabetic properties, but its beneficial effects have not been fully understood on ovarian disorders in diabetic conditions. In the current project, the impact of ginger extract was investigated on oxidative stress and steroidogenesis-related genes in streptozotocin (STZ)-induced female rats. &#x0D; Materials and Methods: The STZ-induced rats were utilized as a diabetic model and received 200 or 400 mg/kg/day ginger extract for eight weeks. The biochemical factors were measured by standard procedures in this study. Serum levels of insulin and sex hormones were assessed by the enzyme-linked immunosorbent assay (ELISA) technique, and the mRNA expression of target genes was assayed by real-time polymerase chain reaction.&#x0D; Results: An increase in the levels of glucose, testosterone, and malondialdehyde (MDA) as well as a decrease in the levels of insulin, glutathione peroxidase (GPx), 3β-hydroxysteroid dehydrogenase (3βHSD), steroidogenic acute regulatory protein (StAR), 17β-estradiol, and progesterone was observed in the diabetic rats. Ginger (200 mg/kg) exhibited a significant amelioration in the levels of glucose, testosterone, and MDA. Treatment with 200 mg/kg ginger enhanced the levels of GPx, StAR, and 17β-estradiol. Administration with 400 mg/kg ginger extract also ameliorated the level of glucose, testosterone, MDA, and elevated the level of insulin, GPx, 3βHSD, StAR, 17β-estradiol, and progesterone in the diabetic rats.&#x0D; Conclusion: The current study suggests ginger extract protects against ovarian damage in STZ-diabetic rats.

4-Nitrophenol at environmentally relevant concentrations mediates reproductive toxicity in Caenorhabditis elegans via metabolic disorders-induced estrogen signaling pathway

4-Nitrophenol (4-NP), as a toxic and refractory pollutant, has generated significant concern due to its adverse effects. However, the potential toxic effects and mechanism remained unclear. In this study, the reproduction, development, locomotion and reactive oxygen species (ROS) production of Caenorhabditis elegans were investigated to evaluate the 4-NP toxicity. We used metabolomics to assess the potential damage mechanisms. The role of metabolites in mediating the relationship between 4-NP and phenotypes was examined by correlation and mediation analysis. 4-NP (8 ng/L and 8 µg/L) caused significant reduction of brood size, ovulation rate, total germ cells numbers, head thrashes and body bends, and an increase in ROS. However, the oosperm numbers in uterus, body length and body width were decreased in 8 µg/L. Moreover, 36 differential metabolites were enriched in the significant metabolic pathways, including lysine biosynthesis, β-alanine metabolism, tryptophan metabolism, pentose phosphate pathway, pentose and glucuronate interconversions, amino sugar and nucleotide sugar metabolism, starch and sucrose metabolism, galactose metabolism, propanoate metabolism, glycerolipid metabolism, and estrogen signaling pathway. The mechanism of 4-NP toxicity was that oxidative stress caused by the perturbation of amino acid, which had effects on energy metabolism through disturbing carbohydrate and lipid metabolism, and finally affected the estrogen signaling pathway to exert toxic effects. Moreover, correlation and mediation analysis showed glycerol-3P, glucosamine-6P, glucosamine-1P, UDP-galactose, L-aspartic acid, and uracil were potential markers for the reproduction and glucose-1,6P2 for developmental toxicity. The results provided insight into the pathways involved in the toxic effects caused by 4-NP and developed potential biomarkers to evaluate 4-NP toxicity.