Regular Estrous Cycles Research Articles

Nicotinamide Mononucleotide Improves Endometrial Homeostasis in a Rat Model of Polycystic Ovary Syndrome by Decreasing Insulin Resistance and Regulating the Glylytic Pathway.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that can lead to insulin resistance (IR) and dysregulation of glucose metabolism, resulting in an imbalance in the endometrial environment, which is unfavorable for embryo implantation of PCOS. This study aims to investigate whether nicotinamide mononucleotide (NMN) improves the stability of the endometrium in a rat model of PCOS and identifies whether it is related to reduce IR and increase glycolysis levels and its potential signaling pathway. Female Sprague-Dawley (SD) rats are fed letrozole and a high-fat diet (HFD) to form the PCOS model, then the model rats are treated with or without NMN. It randomly divided into control, PCOS, and PCOS-NMN groups according to the feeding and treating method. Compared with the PCOS group, the regular estrous cycles are restored, the serum androgen (p<0.01) and fasting insulin levels (p<0.05) are reduced, and endometrial morphology (p<0.05) is improved in NMN-PCOS group. Furthermore, NMN inhibits endometrial cell apoptosis, improves endometrial decidualization transition, reduces IR, restores the expression of glycolysis rate-limiting enzymes, and activates the PI3K/AKT pathway in the uterus. These results suggest that NMN enhances endometrial tissue homeostasis by decreasing uterine IR and regulating the glycolysis through the PI3K/AKT pathway.

7869 Conditional deletion of androgen receptors from kisspeptin neurons only partially rescues the reproductive phenotype of a prenatal androgen-induced mouse model of polycystic ovary syndrome

Abstract Disclosure: A.G. Novak: None. A.V. Petriv: None. D.B. Lohr: None. K.M. Dillon: None. N.T. Neifert: None. A.M. Moore: None. Polycystic ovary syndrome (PCOS) is a prevalent cause of infertility in people with ovaries of reproductive age. Although the etiology of PCOS remains unclear, research in the clinic and with animal models suggests that hyperandrogenism (the presence of elevated circulating androgens) plays a significant role in the development of reproductive dysfunction, including irregular menstrual/estrous cycles and altered ovarian morphology. Although the site at which androgens disrupt the reproductive axis is unclear, neurons expressing kisspeptin are crucial regulators of the hypothalamic-pituitary-gonadal axis and express androgen receptors. Therefore, we hypothesize that androgen signaling at kisspeptin cells is a critical mediator of reproductive dysfunction in PCOS. To test this, we utilized Cre-lox technology to conditionally delete androgen receptors from kisspeptin cells (KARKO) in a commonly used mouse model of PCOS induced by using prenatal dihydrotestosterone treatment (prenatal androgen-treated (PNA) mice). To assess estrous cyclicity, vaginal cytology was examined daily for three weeks beginning at 50 days of age. Prenatal vehicle-treated (PNV) wild-type (WT) and PNV KARKO mice (n=6/group) exhibited regular estrous cycles with no significant differences in the percentage of time spent in proestrus, estrus, or metestrus/diestrus, indicating androgen receptors are not required to maintain fertility. As expected, PNA WT mice (n=6) rarely entered proestrus, spent significantly less time in estrus (p&amp;lt;0.05), and spent significantly more time in metestrus and diestrus (p&amp;lt;0.001) compared to the PNV groups (n=6/group, two-way ANOVA), replicating the previously reported acyclic phenotype of PNA mice. No significant differences in the percentage of time spent in cycle stages were detected between PNA WT and PNA KARKO (n=5) mice in this analysis, suggesting androgen signaling at kisspeptin cells is not required to induce acyclicity in PNA mice. Despite this acyclic phenotype, preliminary data using ovarian sections (5μm thickness) stained with hematoxylin and eosin revealed that the percentage of ovarian area composed of corpora lutea was significantly elevated in PNA KARKO mice (n=3) compared to PNA WT mice (n=4) (p&amp;lt;0.05, one-way ANOVA). Further, in this analysis, the area composed of corpora lutea in PNA KARKO mice was not significantly different from PNV WT and KARKO controls (n=6/group), suggesting PNA KARKO mice exhibit a comparable ovulation rate to fertile controls. Together, these data show that androgen signaling at kisspeptin cells partially contributes to the development of anovulation in PNA mice. However, additional mechanisms likely contribute to developing the full PCOS-like reproductive phenotype. Presentation: 6/1/2024

The effect of norepinephrine on ovarian dysfunction by mediating ferroptosis in mice model.

Studies have shown that stress is associated with ovarian dysfunction. Norepinephrine (NE), a classic stress hormone involved in the stress response, is less recognized for its role in ovarian function. In this study, an NE-treated mouse model is induced by intraperitoneal injection of NE for 4 weeks. Compared with normal control mice, NE-treated mice show disturbances in the estrous cycle, decreased levels of anti-Mullerian hormone (AMH) and estradiol (E2), and increased level of follicle-stimulating hormone (FSH). Additionally, the numbers of primordial follicles, primary follicles, secondary follicles, and antral follicles are decreased, whereas the number of atretic follicles is increased in NE-treated mice, indicating NE-induced ovarian dysfunction. RNA sequencing further reveals that genes associated with ferroptosis are significantly enriched in NE-treated ovarian tissues. Concurrently, the levels of reactive oxygen species (ROS), ferrous ions, and malondialdehyde (MDA) are increased, whereas the expression level of glutathione peroxidase 4 (GPX4) is decreased. To elucidate the mechanism of NE-induced ferroptosis in ovaries and the potential reversal by Coenzyme Q10 (CoQ10), an antioxidant, we conduct both in vitro and in vivo experiments. In vitro, the granulosa cell line KGN, when treated with NE, shows decreased cell viability, reduced expression of GPX4, elevated levels of ferrous ion and ROS, and increased MDA level. However, these NE-induced changes are reversed by the addition of CoQ10. Compared with the NE group, the NE-treated mice supplemented with CoQ10 present increased GPX4 level and decreased iron, ROS, and MDA levels. Moreover, the differential expression of genes associated with ferroptosis induced by NE is ameliorated by CoQ10 in NE-treated mice. Additionally, CoQ10 improves ovarian function, as evidenced by increased ovarian weight, more regular estrous cycles, and an increase in follicles at various stages of growth in NE-treated mice. In conclusion, NE induces ovarian dysfunction by triggering ferroptosis in ovarian tissues, and CoQ10 represents a promising approach for protecting reproductive function by inhibiting ferroptosis.

Diabetes mellitus and female sexual response: what do animal models tell us?

One of the less explored effects of diabetes mellitus (DM) is female sexual dysfunction. Females of different species have been used as models. To analyze the information of animal models of DM and female sexual response (FSR). The literature of FSR in models of DM was reviewed. Paradigm- and diabetes-dependent changes have been found in various aspects of the FSR. Females in a type 1 DM (DM1) model show a decrease in the number of proestrus events, and ovariectomized females treated with sex hormones have been used. In these females, a reduction in lordosis has been reported; in proceptivity, the data are contradictory. These females present a decrease in sexual motivation that was restored after exogenous insulin. In the type 2 DM (DM2) model, females show regular estrous cycles, normal levels of lordosis behavior, and, depending on the paradigm, decreased proceptivity. These females display normal preference for sexually active males or their olfactory cues when having free physical contact; they lose this preference when tested in paradigms where physical interaction is precluded. Preclinical data showing the high deleterious effects of a DM1 model and the less drastic effects under a DM2 model are in accordance with clinical data revealing a much higher prevalence of sexual dysfunction in women with DM1 than DM2. The main strength is the analysis of the changes in various components of FSR in 2 models of DM. The main limitation is the difficulty in extrapolating the data on FSR from rats to women and that most studies focus on evaluating the impact of severe or chronic-moderate hyperglycemia/hyperinsulinemia on the sexual response, without considering other pathophysiologic alterations generated by DM. Females with severe hyperglycemia have a decrease in FSR, while those with moderate hyperglycemia show much less drastic effects.

Injectable Biomimetic Hydrogel Constructs for Cell-Based Menopausal Hormone Therapy with Reduced Breast Cancer Potential.

Hormone replacement therapy (HRT) has been a primary method in menopausal women and patients with ablated ovaries, but safety has been a concern. Cell-based HRT has emerged as an alternative approach without side effects causing pharmaceutical HRT via 3-dimensionally engineered constructs layering ovarian hormone-producing cells. In this study, we applied micro-sized ovarian cell-laden hydrogel beads as an approach to cell-based HRT using a minimally invasive method in the menopausal rat model. Here, we constructed GC/TC-laden microbeads (GTBs; GC, granulosa cell; TC, theca cell) that allow crosstalk between endocrine cells, encapsulating multiple beads for the figuration of the original ovary. We assessed the ovarian hormone production function of GTB through invitro culture for 90 days. We applied it to a menopausal rat model and confirmed that GTB-injected rats restored their endocrine function, leading to the regeneration of the thinned endometrium and the maintenance of regular estrous cycles in some individuals. Additionally, it was observed to alleviate menopausal symptoms, including body weight gain and osteoporosis. Notably, the GTB-injected rats did not show mammary gland hyperplasia observed in the pharmaceutical HRT groups and exhibited fewer p53- and KI67-positive and an increase in phosphatase and tensin homolog-positive mammary gland epithelial cells compared to pharmaceutical hormone-treated rats. These results suggest that GTB-based HRT could present a lower risk of breast cancer compared to conventional pharmaceutical-HRT use. Our study highlights the potential of cell-based HRT using an injectable artificial ovary, offering a safer alternative for women requiring HRT.

Therapeutic effects of stevia aqueous extract alone or in combination with metformin in induced polycystic ovary syndrome rats: Gene expression, hormonal balance, and metabolomics aspects

This study aimed to assess the individual and combined effects of SAE and Met on the expression of genes related to insulin signaling, oxidative stress, hormonal imbalance, insulin resistance, and dyslipidemia in rats with induced PCOS. The estrous cycle of 50 adult Wistar female rats was monitored through vaginal smears. Subsequently, the rats were randomly assigned into five groups of 10, including control (receiving 1ml of carboxymethyl cellulose for 49 days), induction (letrozole at 1mg/kg/d for 21 days), SAE, Met, and SAE/Met. SAE and Met were orally administered at doses of 400mg/kg/d and 250mg/kg/d on day 22 and continued for an additional 28 days. Vaginal smears were analyzed, and gene expression levels of GLUT4, SIRT1, TNF-α, and INSR were evaluated using RT-qPCR. Antioxidant parameters were assessed using detection kits. Treatment with SAE and Met restored a regular estrous cycle pattern in PCOS rats. Furthermore, SAE and Met treatment improved hormonal balance, dyslipidemia, and hyperglycemia in the rats. Administration of SAE and Met significantly elevated levels of antioxidant enzymes SOD and GPx in ovarian tissue (P<0.001). Additionally, mRNA levels of GLUT4, SIRT1, and INSR were significantly increased in ovarian tissue following SAE and Met treatment, while TNF-α gene expression decreased significantly (P<0.0001). The findings suggest that SAE and Met aqueous extract exert protective effects on letrozole-induced PCOS in rats by modulating gene expression associated with insulin signaling and oxidative stress.

Distribution and morphologic characterization of telocytes in rat ovary and uterus: insights from ultrastructural and immunohistochemical analysis

Telocytes (TCs) are characterized by a small oval-shaped cell body with long prolongations that are called telopods (Tps). PDGFR-β and c-kit markers may assist for the immunohistochemical identification of TCs; however, by these means they cannot be identified with absolute specificity. Transmission electron microscopy (TEM) is considered as a gold standard method for TCs observation. Studies on TCs in the female reproductive system are limited, and there is a lack of awareness regarding TCs in rat ovaries. We aimed to demonstrate the existence and morphology of TCs in rat ovaries, alongside previously studied TCs in rat uteri. Thus, ovaries and uteri from young adult Sprague–Dawley female rats (n = 8) with regular estrous cycles were collected. Then, left ovaries and uteri were proccessed for TEM analysis, while the right ones were used for immunohistochemistry. As a result, TCs were seen throughout the rat’s ovarian stroma with their characteristic cell bodies, Tps, podomes (Pds) and podomers (Pdms). Tps were situated within the thecal layer of the follicles, surrounding the corpus luteum and blood vessels. Ovarian TCs were recognized to have relationship with other TCs/stromal cells. Subsequently, TCs were seen in stroma of endometrium with surrounding blood vessels and uterine glands, myometrium and perimetrium in rat uteri. There was also no statistical significance between the number of c-kit+ and PDGFR-β+ telocyte-like cells in both rat ovarian (p = 0.137) and endometrial stroma (p = 0.450). Further investigation of the roles and functions of TCs in the female reproductive system is needed.

Effect of Oral Administration of Dehydroepiandrosterone on PCOS-Like Phenotype of Female C57BL/6 Mice

We aim to evaluate the efficacy and optimal dose of orally administered DHEA in the PCOS mice model by assessing their ovarian morphology and serum FSH, LH, and testosterone levels. Female C57BL/6 mice were divided into a control group (n=5, received daily injections of 0.2 ml sesame oil) and an experimental group, which was further classified into 1) D-45 group (n=5), 2) D-60 (n=5), and 3) D-90 group (n=5) that were treated with 45, 60, and 90 mg/Kg body weight of oral DHEA. After modelling, mice in the control group had a regular estrous cycle, while mice in all experimental groups had a disturbed estrous cycle. Ovarian histology showed several growing follicles and some corpora lutea (CL) in the control, D-60, and D-90 groups. However, some large antral follicles and decreased CL were observed in the D-45 group. Serum FSH was significantly lower in the D-45 group than in the control group (3.73 ± 0.12 vs. 5.28 ± 0.31 mIU/mL, P&lt;0.01), but D-60 and D-90 groups had a similar FSH level to the control group (P&gt;0.05). The serum level of LH and testosterone were significantly elevated in the D-45 group than in the control group (2.52 ± 0.43 vs. 1.30 ± 0.33 mIU/mL, P&lt;0.01 and 1.80 ± 0.32 vs. 1.24 ± 0.23 ng/mL, P&lt;0.01, respectively). Still, the level of LH and testosterone in the D-60 and the D-90 groups was comparable to the control group (P&gt;0.05). Our study suggests that oral administration of DHEA is efficacious in establishing PCOS-like phenotype in mice with the suggested optimal dosage of 45 mg/Kg body weight.

Effect of acupuncture at "Zhibian" (BL 54) through "Shuidao" (ST 28) on PI3K/AKT/FOXO3a pathway in mice with poor ovarian response

To observe the protective effect of acupuncture at "Zhibian" (BL 54) through "Shuidao (ST 28)" based on the PI3K/AKT/FOXO3a pathway in mice with poor ovarian response (POR), and to explore the possible mechanism of acupuncture in inhibiting ovarian granulosa cells apoptosis in POR. A total of 45 mice with regular estrous cycles were randomly divided into a blank group, a model group and an acupuncture group, with 15 mice in each group. Mice in the model group and the acupuncture group were given triptolide suspension (50 mg•kg-1•d-1) by gavage for 2 weeks to establish POR model. After successful modeling, mice in the acupuncture group were given acupuncture at "Zhibian" (BL 54) through "Shuidao" (ST 28) for 2 weeks, once a day, 20 min each time. Ovulation induction was started the day after the intervention ended, and samples were taken from each group after ovulation induction. Vaginal smears were used to observe changes in the estrous cycle of mice. The number of oocytes retrieved, ovarian wet weight, final body weight, and ovarian index were measured. The levels of anti-Mullerian hormone (AMH), follicle-stimulating hormone (FSH), estradiol (E2), and luteinizing hormone (LH) in serum were detected by ELISA. The morphology of ovarian tissue was observed by HE staining. The apoptosis of ovarian granulosa cells was detected by TUNEL staining. The mRNA expression of PI3K, AKT, and FOXO3a in ovarian tissue was detected by real-time fluorescence quantitative PCR. The protein expression of Bcl-2 associated X protein (BAX), caspase-3, phosphorylated phosphatidylinositol 3-kinase (p-PI3K), and phosphorylated protein kinase B (p-AKT) in ovarian tissue was detected by Western blot. Compared with the blank group, the rate of estrous cycle disorder in the model group was increased (P<0.01); compared with the model group, the rate of estrous cycle disorder in the acupuncture group was decreased (P<0.01). Compared with the blank group, the number of oocytes retrieved, ovarian wet weight, ovarian index, and final body weight in the model group were decreased (P<0.01); compared with the model group, the number of oocytes retrieved, ovarian index, and ovarian wet weight were increased (P<0.01, P<0.05), and there was no significant difference in final body weight (P>0.05) in the acupuncture group. Compared with the blank group, the serum levels of FSH and LH were increased (P<0.01), and the serum levels of AMH and E2 were decreased (P<0.01) in the model group; compared with the model group, the serum levels of FSH and LH were decreased (P<0.01, P<0.05), and the serum levels of AMH and E2 were increased (P<0.01, P<0.05) in the acupuncture group. Compared with the blank group, the number of normal developing follicles in ovarian tissue in the model group was decreased and the morphology was poor, while the number of atretic follicles increased; compared with the model group, the number, morphology, and granulosa cell structure of follicles in the acupuncture group improved to varying degrees, and the number of atretic follicles decreased. Compared with the blank group, the apoptosis rate of ovarian granulosa cells in the model group was increased (P<0.01); compared with the model group, the apoptosis rate of ovarian granulosa cells in the acupuncture group was decreased (P<0.01). Compared with the blank group, the FOXO3a mRNA expression and caspase-3 and BAX protein expression in ovarian tissue in the model group were increased (P<0.01), and the mRNA expression of PI3K and AKT and the protein expression of p-PI3K, p-AKT, and p-FOXO3a in ovarian tissue were decreased (P<0.01); compared with the model group, the mRNA expression of FOXO3a and protein expression of caspase-3 and BAX in ovarian tissue in the acupuncture group were decreased (P<0.05, P<0.01), and the mRNA expression of PI3K and AKT and the protein expression of p-PI3K, p-AKT, and p-FOXO3a in ovarian tissue were increased (P<0.01, P<0.05). Acupuncture at "Zhibian" (BL 54) through "Shuidao" (ST 28) could inhibit ovarian cell apoptosis, and improve ovarian function in POR mice, and its mechanism may be related to the regulation of key factors in the PI3K/AKT/FOXO3a pathway.

Dehydroepiandrosterone with a high-fat diet treatment at inducing polycystic ovary syndrome in rat model

ObjectiveThis study aimed to evaluate the effects of dehydroepiandrosterone (DHEA) and DHEA combined with a high-fat diet (HFD) treatment of reproductive and endocrine metabolism in rats and then identify an ideal model of polycystic ovary syndrome (PCOS). MethodsThree-week-old female Sprague–Dawley rats were injected subcutaneously with DHEA or oil, fed with or without a HFD, for 21 days, during which body weight, feed intake, and estrous cycle monitoring were carried out. Fasting blood glucose was measured, and serum fasting insulin, testosterone, dihydrotestosterone (DHT), estradiol, progesterone, luteinizing hormone (LH), anti-Müllerian hormone (AMH), and follicle-stimulating hormone (FSH) were estimated by ELISA. Serum total cholesterol (TC), total triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured by colorimetric assay. Whereas, histologic changes in rat ovaries were evaluated by H&E staining. Ovarian steroid hormone synthases and their protein levels (StAR, 3β-HSD2, 17β-HSD1, CYP11A1, CYP17A1, and CYP19A1) were examined by Western blotting. ResultsBoth DHEA and DHEA + HFD-treated rats lost a regular estrous cycle; had polycystic ovarian changes, significantly higher serum fasting insulin and testosterone levels; and increased ovarian StAR, 3β-HSD2, and CYP11A1 protein levels. Additionally, rats in the DHEA + HFD-treated group were obese; had elevated fasting blood glucose, TG, DHT, AMH levels and LH:FSH ratios; increased ovarian 17β-HSD1 protein levels. ConclusionDHEA combined with HFD treatment is more effective at inducing PCOS than DHEA alone. The reproductive and endocrine metabolic aspects of this method are more consistent with the clinical characteristics of PCOS patients.

Evaluation of wheat (Triticum aestivium L) diet on reproductive functions of adult female rats

Introduction: The relationships between wheat diet, sex hormone and the estrous cycle are important from the perspective of fertility. Aim: This study aims to investigate the effect of wheat diet on weight, estrous cycle, reproductive hormones and histology of the ovary of female Sprague-Dawley rats. Methods: Prior to the test, vaginal smear was monitored daily for 16 days period to select females with normal (regular) estrous cycle. A total of twenty rats with regular estrous cycle weighing between 170-200 g were randomized into four sets of 5 animals each. Group A is the female control and was fed with rat chow, group B, C and D was given 40%, 60%, 100% of wheat diet respectively. The wheat diet was giving respectively for a period of 4 weeks. Estrous cycle pattern was monitored using the vaginal smear for 16 days. At the end of the experiment, the rats were sacrificed and the blood sample were taken for follicle stimulating hormone, luteinizing hormones, estradiol, and progesterone analysis. The histology of the ovary were carried out. Results: The result showed that there was an increase in the weight of the rats that was fed with wheat and the increase was diet dependent. The wheat diets disrupt the order of appearance of normal estrous cycle stages, hence; there was no constancy in the frequency of all cycle stages in the wheat groups, mostly the 100% wheat group. No significant endocrine or histological differences noticed between control and wheat diets groups. Therefore photomicrograph of wheat diet shows large corpus luteum, thick germinal epithelium, zona granulosa and oocyte. Conclusion: Wheat diets disrupt the estrous cycle of the rats; however no adverse effect was noticed on the circulating reproductive hormones and histology of the ovary. However, high consumption of wheat should be taken with precaution.

Testing the Adaptive Sterilization Hypothesis in mice inoculated with Chlamydia muridarum.

The "adaptive sterilization hypothesis" argues that the tendency of sexually transmitted infections (STIs) to cause infertility likely reflects an evolutionary adaptation of these pathogens. For example, some STIs can lead to bilateral occlusions of the oviducts and sterile matings. Cycling females that do not spend time gestating and lactating are ready to mate sooner than fertile females, and therefore, likely to mate more frequently and possibly more promiscuously. These sexual activities are associated with enhanced transmissibility of STIs, and tubal occlusion is a proximate mechanism by which STIs can increase fitness. Our principal objectives were to determine whether female mice inoculated with Chlamydia muridarum mate more frequently than mice inoculated with sterile saline and to test the hypothesis that tubal occlusion following C. muridarum infection modulates mating behavior in a manner that might increase transmissibility of Chlamydia. Similar to C. trachomatis infections in human females, C. muridarum can ascend the reproductive tract of mice, damage and occlude the oviducts, and cause infertility. However, ovarian function and mating activity are maintained following tubal occlusion. Twenty C57Bl/6 mice with regular estrous cycles were given intra-vaginal inocula of C. muridarum and 32 days later paired with a male for 90 days. Nine saline-treated females served as controls. Three Chlamydia-inoculated females were rendered infertile due to bilateral oviductal damage and mated 8 (±0.0) times. Control females mated on average 4.6 (±0.3) times, and 17 Chlamydia-inoculated fertile females, including six females with only a single oviduct occluded, mated on average 4.7 (±0.2) times. Chlamydia-inoculated fertile females with unilateral oviductal damage had significantly smaller average litter sizes as compared to females inoculated with saline. Females with unilateral tubal occlusion also tended to wean fewer pups than saline controls over the course of 90 days. Female mice with Chlamydia-induced tubal infertility mated more frequently (approximately every 11 d) than did fertile females (approximately every 20 d), which is consistent with the adaptive sterilization hypothesis. To determine whether Chlamydia-induced sterilization is truly adaptive, future studies will need to demonstrate increased sexual transmissibility, and possibly increased promiscuity, within populations of freely breeding mice.

Determination of Maximum Tolerable Cold Ischemia Time in a Mouse Model of Cervical Heterotopic Uterus Transplantation.

Uterus transplantation (UTx) is an emerging treatment for uterine factor infertility. Determining the maximum tolerable cold ischemia time is crucial for successful UTx. However, the limit for cold ischemia in the uterus is unclear. This study aimed to examine cold ischemia's effects on mouse uteri and identify the maximum cold ischemia duration that uteri can endure. We systematically assessed the tolerance of mouse uteri to extended cold ischemia, 24 h, 36 h, and 48 h, using the cervical heterotopic UTx model. Multiple indicators were used to evaluate ischemia-reperfusion injury, including reperfusion duration, macroscopic examination, oxidative stress, inflammation, and histopathology. The function of transplants was evaluated through estrous cycle monitoring and embryo transfer. Mouse uteri subjected to 48 h of cold ischemia exhibited significant delays and insufficiencies in reperfusion, substantial tissue necrosis, and loss of the estrous cycle. Conversely, uteri that underwent cold ischemia within 36 h showed long survival, regular estrous cycles, and fertility. Our study demonstrated that mouse uteri can endure at least 36 h of cold ischemia, extending the known limits for cold ischemia and providing a pivotal reference for research on the prevention and treatment of cold ischemic injury in UTx.

Multiple treatments with human embryonic stem cell-derived mesenchymal progenitor cells preserved the fertility and ovarian function of perimenopausal mice undergoing natural aging

ObjectivesCurrently, no approved stem cell-based therapies for preserving ovarian function during aging. To solve this problem, we developed a long-term treatment for human embryonic stem cell-derived mesenchymal progenitor cells (hESC-MPCs). We investigated whether the cells retained their ability to resist ovarian aging, which leads to delayed reproductive senescence.Materials and methodsIn a middle-aged female model undergoing natural aging, we analyzed whether hESC-MPCs benefit the long-term maintenance of reproductive fecundity and ovarian reservoirs and how their transplantation regulates ovarian function.ResultsThe number of primordial follicles and mice with regular estrous cycles were increased in perimenopausal mice who underwent multiple introductions of hESC-MPCs compared to age-matched controls. The estradiol levels in the hESC-MPCs group were restored to those in the young and adult groups. Embryonic development and live birth rates were higher in the hESC-MPC group than in the control group, suggesting that hESC-MPCs delayed ovarian senescence. In addition to their direct effects on the ovary, multiple-treatments with hESC-MPCs reduced ovarian fibrosis by downregulating inflammation and fibrosis-related genes via the suppression of myeloid-derived suppressor cells (MDSCs) produced in the bone marrow.ConclusionsMultiple introductions of hESC-MPCs could be a useful approach to prevent female reproductive senescence and that these cells are promising sources for cell therapy to postpone the ovarian aging and retain fecundity in perimenopausal women.

Mitigating Cold Stress in Livestock by Nutritional Interventions: A Comprehensive Review

Climate change has been the major threat to livestock systems sustainability globally. This climate change has provoked many stressors, for instance, cold, heat, humidity, rain, ice and wind, that can directly or indirectly exert influence on the endocrine system and impact the performance of an animal including their production potential, reproductive system and regular estrous cycle. Also, the environmental stressors can contribute to the amenability of animals to infections; it is therefore, vital to understand how stressors alter the animal’s adaptive capacity and efficient methods in coping stress. This review aims at the scientific evidences regarding challenges due to cold stress and its potential mitigation by nutritional interventions. The cold is amongst the most potential environmental stressors which can adversely affect production potential as well as the growth of animals. Under cold stress the animals’ dietary intake increases, but the production capacity declines, furthermore, it can also culminate in physiological fluctuations, behavioral shift, tissue and intestinal impairment and soaring death rate. Maintenance of animal in its thermoneutral zone is important, otherwise any deviation from it proves life threatening. So, to cut back on the economic losses timely course of action must be taken to prevent the damages ascribed to the stressor. To maintain the production performance along with profitability, it is thus recommended to adapt scientific feeding regimens and also incorporate feed supplements (especially vitamins and minerals) to combat the devastating effects of cold stress.

Mechanism of resveratrol in protecting ovary in poor ovarian response mice by regulating Hippo signaling pathway

This study observed the protective effect of resveratrol(Res) on ovarian function in poor ovarian response(POR) mice by regulating the Hippo signaling pathway and explored the potential mechanism of Res in inhibiting ovarian cell apoptosis. Female mice with regular estrous cycles were randomly divided into a blank group, a model group, and low-and high-dose Res groups(20 and 40 mg·kg~(-1)), with 20 mice in each group. The blank group received an equal volume of 0.9% saline solution by gavage, while the model group and Res groups received suspension of glycosides of Triptergium wilfordii(GTW) at 50 mg·kg~(-1) by gavage for two weeks to induce the model. After modeling, the low-and high-dose Res groups were continuously treated with drugs by gavage for two weeks, while the blank group and the model group received an equal volume of 0.9% saline solution by gavage. Ovulation was induced in all groups on the day following the end of treatment. Finally, 12 female mice were randomly selected from each group, and the remaining eight female mice were co-housed with male mice at a ratio of 1∶1. Changes in the estrous cycle of mice were observed using vaginal cytology smears. The number of ovulated eggs, ovarian wet weight, ovarian index, and pregnancy rate of mice were measured. The le-vels of anti-Mullerian hormone(AMH), follicle-stimulating hormone(FSH), estradiol(E_2), and luteinizing hormone(LH) in serum were determined using enzyme-linked immunosorbent assay(ELISA). Ovarian tissue morphology and ovarian cell apoptosis were observed using hematoxylin-eosin(HE) staining and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL) staining, respectively. The protein expression levels of yes-associated protein(YAP) 1 and transcriptional coactivator with PDZ-binding motif(TAZ) were detected by immunohistochemistry(IHC), while the changes in protein expression levels of mammalian sterile 20-like kinase(MST) 1/2, large tumor suppressor(LATS) 1/2, YAP1, TAZ, B-cell lymphoma-2(Bcl-2), and Bcl-2 associated X protein(Bax) were determined by Western blot. The results showed that compared with the blank group, the model group had an increased rate of estrous cycle disruption in mice, a decreased number of normally developing ovarian follicles, an increased number of blocked ovarian follicles, increased ovarian granulosa cell apoptosis, decreased ovulation, reduced ovarian wet weight and ovarian index, increased serum FSH and LH levels, decreased AMH and E_2 levels, decreased protein expression levels of YAP1 and TAZ in ovarian tissues, increased relative expression levels of MST1/2, LATS1/2, and Bax proteins, and decreased relative expression levels of YAP1, TAZ, and Bcl-2 proteins. Additionally, the number of embryos per litter significantly decreased after co-housing. Compared with the model group, the low-and high-dose Res groups exhibited reduced estrous cycle disruption rates in mice, varying degrees of improvement in the number and morphology of ovarian follicles, reduced numbers of blocked ovarian follicles, improved ovarian granulosa cell apoptosis, increased ovulation, elevated ovarian wet weight and ovarian index, decreased serum FSH and LH levels, increased AMH and E_2 levels, elevated protein expression levels of YAP1 and TAZ in ovarian tissues, decreased relative expression levels of MST1/2, LATS1/2, and Bax proteins, and increased relative expression levels of YAP1, TAZ, and Bcl-2 proteins. Furthermore, the number of embryos per litter increased to varying degrees after co-housing. In conclusion, Res effectively inhibits ovarian cell apoptosis in mice and improves ovarian responsiveness. Its mechanism may be related to the regulation of key molecules in the Hippo pathway.

Pulsed Low-Intensity Focused Ultrasound (LIFU) Activation of Ovarian Follicles.

Objective: A biological system's internal morphological structure or function can be changed as a result of the mechanical effect of focused ultrasound. Pulsed low-intensity focused ultrasound (LIFU) has mechanical effects that might induce follicle development with less damage to ovarian tissue. The potential development of LIFU as a non-invasive method for the treatment of female infertility is being considered, and this study sought to explore and confirm that LIFU can activate ovarian follicles. Results: We found a 50% increase in ovarian weight and in the number of mature follicles on the ultrasound-stimulated side with pulsed LIFU and intraperitoneal injection of 10 IU PMSG in 10-day-old rats. After ultrasound stimulation, the PCOS-like rats had a decrease in androgen levels, restoration of regular estrous cycle and increase in the number of mature follicles and corpora lutea, and the ratio of M1 and M2 type macrophages was altered in antral follicles of PCOS-like rats, consequently promoting further development and maturation of antral follicles. Conclusion: LIFU treatment could trigger actin changes in ovarian cells, which might disrupt the Hippo signal pathway to promote follicle formation, and the mechanical impact on the ovaries of PCOS-like rats improved antral follicle development.

Direct infiltration effects of dimethyl sulfoxide into ovarian bursas on spontaneous ovulation and the estrous cycle of the rat: antagonism on the type 2 dopaminergic receptor

We studied effects of microinjection (MI) into ovarian burses (OB) of infiltering agent dimethyl sulfoxide (DMSO) on number of ova shed (NOS) and estrous cycle (EC) of adult female rats with fourth day regular estrous cycles (REC), and we compared these effects with a MI of 100µg sulpiride solution in DMSO. Between 13:00- 14:00h of different days of EC, CER groups received 20µL of pure DMSO into both OB; the sham groups received MI with 20µL distillated water (H2O) into each OB. All rats with MI performed and an intact cyclic rat group were autopsied in the morning of next estrous vaginal shown (EVS). Both DMSO and H2O MI does not modify the EC duration and NOS. Other groups of cyclic rats received a MI with 20µL sulpiride solution into each OB and were autopsied at next EVS. Just the sulpiride MI performed on diestrous-1 day delayed 24h the next EVS, but that don’t occur in other sulpiride groups. The NOS were not modified in all experimental group. The DMSO direct administration in ovarian tissue does not affect gonadal primordial functions and its use is recommended like an infiltrating agent of non-polar drugs.

Dapagliflozin Ameliorates Ovulation Disorders via Attenuating Activated Microglia-Mediated Hypothalamic Inflammation in HFD-Fed Mice

Introduction: Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have shown neuroprotective effects in obese mice. However, whether SGLT2i can ameliorate high-fat diet (HFD)-related ovulation disorders remains unknown. The aim of this research was to investigate whether dapagliflozin improves HFD-induced ovulatory dysfunction by attenuating microglia-mediated hypothalamic inflammation. Methods: C57BL/6J female mice fed HFD were treated with dapagliflozin (1 mg/kg) for 22 weeks. Plasma insulin, leptin, luteinizing hormone (LH), estradiol (E2), and IL-1β levels were also tested. Microglial morphology, cell numbers, and SGLT2 expression were evaluated using immunofluorescence. The expression of IL-1β, NLRP3, kisspeptin, gonadotropin-releasing hormone (GnRH), SGLT2, insulin, and leptin receptors in the hypothalamus was determined using immunohistochemical staining. We also examined the effects of dapagliflozin on glucose metabolism and the release of inflammatory factor in palmitic acid (PA)-treated HMC3 cells. Results: As expected, dapagliflozin improved HFD-induced metabolic disturbances, peripheral versus central insulin and leptin resistance and also restored the regular estrous cycle. Furthermore, dapagliflozin blunted microglia activation, NLRP3 inflammasome priming, hypothalamic inflammation, and increased the expression of GnRH and kisspeptin at proestrus in the hypothalamus. Additionally, dapagliflozin markedly reduced IL-6 and NO release and fat accumulation, decreased lactic acid production and glucose consumption, and inhibited mammalian target of rapamycin (mTOR) and hexokinase 2 (HK2) expression in PA-treated HMC3 cells. These effects suggest that dapagliflozin reduced the mTOR/HK2-mediated aerobic glycolysis. Conclusions: Dapagliflozin improved HFD-related ovulation disorders by regulating glucose metabolism through mTOR/HK2 signaling and attenuating microglia-mediated hypothalamic inflammation. These results validate the novel role for the neuroprotection of SGLT2i in HFD-induced obesity and ovulation disorders.

A mouse model of oral contraceptive exposure: Depression, motivation, and the stress response

Hormonal contraceptives, including oral contraceptives (OCs), regulate hormonal cycles and broadly affect physiological processes, including stress responsivity. Whereas many users describe overall improved mood, up to 10 % of OC users experience adverse effects, including depression and anxiety. Given the link between regulation of hypothalamic-pituitary-adrenal (HPA) axis, stress exposure, and risk for depression, it is likely that OC-effects on stress mediate increased risk or increased resilience to these disorders. In this study, we developed and characterized a tractable mouse model of OC exposure with which to identify the mechanisms underlying OC modulation of brain, behavior, and mood. Specifically, we aimed to determine whether translationally relevant doses of OC-hormones in mice mimic changes in stress responsivity observed in humans taking OCs and describe behavioral changes during OC exposure. Young adult female C57Bl/6 N mice received daily ethinyl estradiol (EE) and levonorgestrel (LVNG) in 10 % sucrose, EE and drospirenone (DRSP) in 10 % sucrose, or 10 % sucrose alone. Translationally relevant doses of EE + LVNG-exposure, but not EE + DRSP, suppressed the acute stress response, consistent with effects observed in human OC users. EE + LVNG caused a specific anhedonia-like effect, without broad changes in stress-coping behavior, other depression-like behaviors, or anxiety-like behaviors. The suppression of regular estrous cycling, together with the blunting of the corticosterone response to acute stress, demonstrate the utility of this model for future studies to identify the mechanisms underlying OC interactions with stress, motivation, and risk for depression.