Angiogenesis in developing follicle and corpus luteum

The relationship between oxidative stress and apoptosis of histopathological changes in the ovary made by mad honey containing grayanotoxin

The purpose of this study is to determine the effects of grayanotoxin in mad honey on ovarian tissue folliculogenesis in terms of cell death and nitric oxide expression. Three groups of 18 female Sprague-Dawley rats were formed. The first group received mad honey (80 mg/kg), the second group received normal honey (80 mg/kg), and the third group was the control. The first and second groups received normal and mad honey by oral gavage for 30 days before being sacrificed under anesthesia. Caspase 3 immunostaining showed a moderate to strong response, particularly in the mad honey group. In the mad honey group, immunostaining for caspase 8 and caspase 9 revealed a moderate immunoreaction in the granulosa cells of the Graaf follicles. The majority of Graaf follicles exhibited TUNEL positive in the mad honey group. The iNOS immunoreaction revealed a high level of expression in the mad honey group. In all three groups, eNOS immunostaining showed weak reactivity. According to the findings of apoptotic and nitric oxide marker expression, it was determined that mad honey may result in an increase in follicular atresia in ovarian follicles when compared to normal honey and control groups.

The role of estrogen metabolites in human ovarian function

Estrogens produced by the ovary play diverse roles in controlling physiological changes in the function of the female reproductive system. Although estradiol acts through classical nuclear receptors, its metabolites (EMs) act by alternative pathways. It has been postulated that EMs act through paracrine-autocrine pathways to regulate key processes involved in normal follicular growth, corpus luteum (CL) development, function, and regression. The present review describes recent advances in understanding the role of EMs in human ovarian physiology during the menstrual cycle, including their role in anovulatory disorders and their action in other target tissues.

New insight into the role of macrophages in ovarian function and ovarian aging

Macrophages (MΦs) are the most abundant leukocytes in mammalian ovaries that have heterogeneity and plasticity. A body of evidence has indicated that these cells are important in maintaining ovarian homeostasis and they play critical roles in ovarian physiological events, such as folliculogenesis, ovulation, corpus luteum formation and regression. As females age, ovarian tissue microenvironment is typified by chronic inflammation with exacerbated ovarian fibrosis. In response to specific danger signals within aged ovaries, macrophages polarize into different M1 or M2 phenotypes, and specialize in unique functions to participate in the ovarian aging process. In this review, we will focus on the physiologic roles of MΦs in normal ovarian functions. Furthermore, we will discuss the roles of MΦs in the process of ovarian senescence, as well as the novel techniques applied in this field.

Primary ovarian insufficiency associated with lenvatinib therapy in a patient with hepatocellular carcinoma: A case report

The therapeutic effects of molecular targeted drugs are, in some cases, more pronounced than those of conventional chemotherapy, and their introduction as a standard treatment is increasing. The present report describes a case of ovarian insufficiency in a young woman caused by tyrosine kinase inhibitor lenvatinib. The 25-year-old woman received lenvatinib (8 mg/day) for 98 days as preoperative chemotherapy for hepatocellular carcinoma. Blood testing the day before starting lenvatinib administration indicated 4.40 mIU/ml luteinizing hormone (LH), 5.2 mIU/ml follicle-stimulating hormone (FSH) and age-equivalent hormone values. Amenorrhea occurred after the start of administration, and 48 days later, the LH level was 41.8 mIU/ml and the FSH level was 44 mIU/ml, indicating a decrease in ovarian function. The patient underwent hepatectomy, and 49 days after the end of lenvatinib administration, the LH level had improved to 4.5 mIU/ml and the FSH level had improved to 2.5 mIU/ml. After the hepatectomy, the patient began to have regular menstrual cycles once again. Ovarian toxicity has not been recognized as a side effect of lenvatinib. However, the present report describes primary ovarian insufficiency considered to be caused by this drug. Potential damage to ovarian function may need to be considered when molecular targeted drugs with the same mechanism of action as lenvatinib are used in young women.

Neo-vascularization-based therapeutic perspectives in advanced ovarian cancer

The process of angiogenesis is well described for its potential role in the development of normal ovaries, and physiological functions as well as in the initiation, progression, and metastasis of ovarian cancer (OC). In advanced stages of OC, cancer cells spread outside the ovary to the pelvic, abdomen, lung, or multiple secondary sites. This seriously limits the efficacy of therapeutic options contributing to fatal clinical outcomes. Notably, a variety of angiogenic effectors are produced by the tumor cells to initiate angiogenic processes leading to the development of new blood vessels, which provide essential resources for tumor survival, dissemination, and dormant micro-metastasis of tumor cells. Multiple proangiogenic effectors and their signaling axis have been discovered and functionally characterized for potential clinical utility in OC. In this review, we have provided the current updates on classical and emerging proangiogenic effectors, their signaling axis, and the immune microenvironment contributing to the pathogenesis of OC. Moreover, we have comprehensively reviewed and discussed the significance of the preclinical strategies, drug repurposing, and clinical trials targeting the angiogenic processes that hold promising perspectives for the better management of patients with OC.

Ligusticum chuanxiong promotes the angiogenesis of preovulatory follicles (F1-F3) in late-phase laying hens

Ligusticum chuanxiong (CX) is a traditional Chinese medicine that is widely planted throughout the world. CX is one of the most important and commonly used drugs to enhance blood circulation. The preovulatory follicles in laying hens have a large number of blood arteries and meridians that feed the follicles' growth and maturation with nutrients, hormones, and cytokines. With the extension of laying time, preovulatory follicles angiogenesis decreased gradually. In this study, we studied the mechanism of CX on preovulatory follicles angiogenesis in late-phase laying hens. The results show that CX extract can increase the angiogenesis of preovulatory follicles (F1-F3) of late-phase laying hens. CX extract can promote vascular endothelial growth factor receptor 2 (VEGFR2) phosphorylation in preovulatory follicles theca layers, promote the proliferation, invasion and migration through PI3K/AKT and RAS/ERK signaling pathways in primary follicle microvascular endothelial-like cells (FMECs). In addition, CX extract can up-regulate the expression of hypoxia inducible factor α (HIF1α) in granulosa cells (GCs) and granulosa layers through PI3K/AKT and RAS/ERK signaling pathways, thereby promoting the secretion of vascular endothelial growth factor A (VEGFA). In conclusion, the current study confirmed the promoting effect of CX extract on the preovulatory follicles angiogenesis, which sets the stage for the design of functional animal feed for late-phase laying hens.

Ovarian, uterine, and luteal vascular perfusions during follicular and luteal phases in the adult cyclic female rabbits with special orientation to their histological detection of hormone receptor

Understanding the does reproductive hemodynamic changes during the estrous cycle is crucial for improving reproductive competence and fertility potential in this species. The objective of this study is to investigate the hemodynamic variations in ovarian (OA) and uterine (UA) arteries, histological and morphometric changes in ovarian and uterine tissues throughout the follicular (FP) and luteal (LP) phases in rabbits and determine estrogen (ER), progesterone (PR) receptors, and vascular endothelial growth factor (VEGF) distributions using immunohistochemistry.

Fourteen adults pluriparous New Zealand rabbits were divided into rabbits at the FP (Day − 1; n = 7) and those at the LP (Day 9; n = 7). Animals were subjected to Doppler, hormonal (estrogen [E2], progesterone [P4], insulin-like growth factor [ILGF], and VEGF), histological, and immunohistochemical analyses. In LP, OA Doppler indices were significantly increased, whereas peak systolic velocity (PSV) was decreased compared with that in FP. UA Doppler indices were significantly decreased in the LP, whereas PSV was increased (P < 0.05). E2 levels were increased in the FP, whereas P4 levels were increased in the LP. The morphometric analysis of uterine tissues during the LP revealed an increase in the mean uterine endometrium length, endometrial connective tissue area percentage (%), endometrial glands number, myometrial area (%) and thickness. Furthermore, ovarian follicles and corpus luteum (CL) displayed strong positive immunoreactivity for ER, PR, and VEGF-A during both phases. The ovarian sections displayed a substantial (P < 0.05) increase in the area % of VEGF-A in the ovarian follicles during FP while in the CL during LP. Conversely, area percentage of VEGF-A immunoreactivity in the uterine luminal and glandular epithelia during the FP and LP revealed no differences. However, the number of VEGF-A–stained blood capillaries revealed an increase during LP than FP. In conclusion, this study demonstrated for the first time the changes in both ovarian and uterine arteries during two different phases of the rabbit cycle in relation to the histo-morphometric analysis and distribution of ER, PR, and VEGF-A, which regulate uterine functions that play a role in reproduction.

Delta-9-tetrahydrocannabinol increases vascular endothelial growth factor (VEGF) secretion through a cyclooxygenase-dependent mechanism in rat granulosa cells

While the effects of delta-9-tetrahydrocannabinol (THC), the psychoactive component of cannabis, have been studied extensively in the central nervous system, there is limited knowledge about its effects on the female reproductive system. The aim of this study was to assess the effect of THC on the expression and secretion of the angiogenic factor vascular endothelial growth factor (VEGF) in the ovary, and to determine if these effects were mediated by prostaglandins. Spontaneously immortalized rat granulosa cells (SIGCs) were exposed to THC for 24hours. Gene expression, proliferation and TNFα-induced apoptosis were evaluated in the cells and concentrations of VEGF and prostaglandin E2 (PGE₂), a known regulator of VEGF production, were determined in the media. To evaluate the role of the prostanoid pathway, cells were pre-treated with cyclooxygenase (COX) inhibitors prior to THC exposure. THC-exposed SIGCs had a significant increase in VEGF and PGE₂ secretion, along with an increase in proliferation and cell survival when challenged with an apoptosis-inducing factor. Pre-treatment with COX inhibitors reversed the THC-induced increase in both PGE₂ and VEGF secretion. Alterations in granulosa cell function, such as the ones observed after THC exposure, may impact essential ovarian processes including folliculogenesis and ovulation, which could in turn affect female reproductive health and fertility. With the ongoing increase in cannabis use and potency, further study on the impact of cannabis and its constituents on female reproductive health is required.

Nanoparticles Accumulate in the Female Reproductive System during Ovulation Affecting Cancer Treatment and Fertility

Throughout the female menstrual cycle, physiological changes occur that affect the biodistribution of nanoparticles within the reproductive system. We demonstrate a 2-fold increase in nanoparticle accumulation in murine ovaries and uterus during ovulation, compared to the nonovulatory stage, following intravenous administration. This biodistribution pattern had positive or negative effects when drug-loaded nanoparticles, sized 100 nm or smaller, were used to treat different cancers. For example, treating ovarian cancer with nanomedicines during mouse ovulation resulted in higher drug accumulation in the ovaries, improving therapeutic efficacy. Conversely, treating breast cancer during ovulation, led to reduced therapeutic efficacy, due to enhanced nanoparticle accumulation in the reproductive system rather than at the tumor site. Moreover, chemotherapeutic nanoparticles administered during ovulation increased ovarian toxicity and decreased fertility compared to the free drug. The menstrual cycle should be accounted for when designing and implementing nanomedicines for females.

Promotion Effect of Angelica Sinensis Extract on Angiogenesis of Chicken Preovulatory Follicles in Vitro

Preovulatory follicles need a network of blood vessels to growth and maturation in hens (Gallus gallus). Angelica sinensis (Oliv.) (AS), a traditional Chinese herb, displays a novel pro-angiogenic activity. The molecular mechanisms underlying AS promoting preovulatory follicles angiogenesis are poorly understand. Several recent studies investigated the expression of vascular endothelial growth factor A (VEGF-A) in angiogenesis. In order to explore the promotion effect of AS extract on angiogenesis of chicken preovulatory follicles, we studied the effect of AS extract on follicle microvascular endothelial-like cells of chicken (FMEC) and granulosa cells (GC). The current study indicated that AS extract could promote the proliferation of FMECs and GCs. The assays of wounding healing, transwell invasion and tube formation showed that AS extract could enhance the invasion and migration ability of FMECs in vitro. The results of western blot and RT-PCR showed that AS extract promoted the phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2) in FMECs by activating the PI3K/AKT signaling pathway. The AS extract activated PI3K/AKT signaling pathway and up-regulated the expressions of hypoxia-inducible factor 1-α (HIF1-α) and VEGF-A in GCs. In addition, treatment of FMECs and GCs with LY294002 (a PI3K inhibitor) significantly down-regulated the phosphorylation of VEGFR2, VEGF-A, and HIF1-α. The mRNA expression levels of PI3K, AKT, VEGF-A, VEGFR2, and HIF1-α were consistent with protein expression levels. In conclusion, our research showed that AS extract can promote the follicle angiogenesis in hens in vitro, providing a basis for application of the traditional Chinese herb AS in poultry production.

Effects of Nerve Growth Factor-β From Bull Seminal Plasma on Steroidogenesis and Angiogenic Markers of the Bovine Pre-ovulatory Follicle Wall Cell Culture

Nerve growth factor-β (NGF) is critical for ovulation in the mammalian ovary and is luteotrophic when administered systemically to camelids and cattle. This study aimed to assess the direct effects of purified bovine NGF on steroidogenesis and angiogenic markers in the bovine pre-ovulatory follicle. Holstein heifers (n = 2) were synchronized with a standard protocol, and heifers with a preovulatory follicle (≥ 12 mm) had the ovary containing the dominant follicle removed via colpotomy. Pre-ovulatory follicles were dissected into 24 pieces containing theca and granulosa cells that were randomly allocated into culture media supplemented with either purified bovine NGF (100 ng/mL) or untreated (control) for 72 h. The supernatant media was harvested for quantification of progesterone, testosterone, and estradiol concentrations, whereas explants were subjected to mRNA analyses to assess expression of steroidogenic and angiogenic markers. Treatment of follicle wall pieces with NGF upregulated gene expression of steroidogenic enzyme HDS17B (P = 0.04) and increased testosterone production (P < 0.01). However, NGF treatment did not alter production of progesterone (P = 0.81) or estradiol (P = 0.14). Consistently, gene expression of steroidogenic enzymes responsible for producing these hormones (STAR, CYP11A1, HSD3B, CYP17A1, CYP19A1) were unaffected by NGF treatment (P ≥ 0.31). Treatment with NGF downregulated gene expression of the angiogenic enzyme FGF2 (P = 0.02) but did not alter PGES (P = 0.63), VEGFA (P = 0.44), and ESR1 (P = 0.77). Collectively, these results demonstrate that NGF from seminal plasma may interact directly on the theca and granulosa cells of the bovine pre-ovulatory follicle to stimulate testosterone production, which may be secondary to theca cell proliferation. Additionally, decreased FGF2 expression in NGF-treated follicle wall cells suggests hastened onset of follicle wall cellular remodeling that occurs during early luteal development.

An integrated in silico analysis highlighted angiogenesis regulating miRNA-mRNA network in PCOS pathophysiology

Background

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrinopathy and a leading cause of anovulatory infertility. Angiogenesis is vital for ovarian folliculogenesis. The expression of angiogenesis-associated genes/proteins is altered in the ovary of PCOS women. However, information on microRNAs (miRNAs) regulating their expression is limited. This study aims to identify dysregulated angiogenesis-related genes in the ovary of women with PCOS, to identify miRNAs regulating them, and to construct a miRNA-mRNA network associated with angiogenesis.

Methods

A comprehensive literature search and reanalysis of seven ovarian GEO microarray datasets were performed to identify differentially expressed angiogenesis-related genes in PCOS. These target genes were used to predict their regulating miRNAs by querying miRNA databases and their expression in the ovary was verified. Panther and STRING database were used for functional enrichment. Gene expression of shortlisted miRNAs was studied in granulosa cells using digital droplet PCR.

Results

The miRNAs expressed in the ovary and potentially targeting dysregulated angiogenesis-related genes in PCOS were identified and those enriched in angiogenesis-related pathways, like VEGF, FGF, PI3K/Akt, Notch signaling, and ECM interaction were shortlisted. Analysis showed PI3K/Akt signaling was the most enriched pathway. MiR-218-5p, miR-214-3p, miR-20a-5p, and miR-140-3p associated with the PI3K/Akt pathway were found to be up-regulated in granulosa cells of women with PCOS.

Conclusions

By in silico analysis, we identified crucial dysregulated angiogenesis-related genes, the miRNA-mRNA interactions, and signaling pathways involved in impaired follicular angiogenesis in PCOS. This work provides a novel insight into the mechanism of aberrant ovarian angiogenesis contributing to PCOS pathophysiology.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10815-022-02396-1.

Expression profile of the Kisspeptin/Kiss1r system and angiogenic and immunological mediators in the ovary of cyclic and pregnant cats

The Kisspeptin/Kiss1r system has been studied in mammalian ovaries. However, there are still no studies on the modulation of this system and its relationship with angiogenic and immunological mediators in the ovary of domestic cats, especially during pregnancy. We evaluated the expression of Kisspeptin/Kiss1r and angiogenic and immunological mediators during folliculogenesis, luteogenesis and luteal regression of cyclic and pregnant cats. The ovary exhibited moderate to intense expression for Kiss1, VEGF, Flk-1, INFγ and MIF in oocytes and the follicular wall, while Kiss1r expression was low in granulosa cells. In these cells, there was also a greater expression of Kiss1, INFγ and MIF, mainly in secondary follicles, while tertiary and preovulatory follicles exhibited greater expression of VEGF and Flk-1 in this layer. In luteogenesis, Kiss1 immunostaining was higher in mature corpora lutea (MCL) of pregnant cats compared to vacuolated CL (VCL) and corpus albicans (CA). Pregnancy also increased the luteal gene expression of Kiss1 as well as Kiss1, Kiss1r, Flk-1, and MIF immunostaining in MCL, while reduced the area of VEGF expression in VCL and luteal mRNA expression of Mif when compared to non-pregnant animals. In addition, positive gene correlation between Kiss1r and Mif was observed in the CL. Kiss1, Kiss1r, Vegf and Mif expression were lower in the CA of cats in anestrus. These findings reveal that the expression of Kisspeptin/Kiss1r and angiogenic and immunological mediators, in the ovary of domestic cats, depend on the follicular and luteal stage, and the luteal expression of these mediators is influenced by pregnancy.

Targeted cancer treatment and fertility: effect of immunotherapy and small molecule inhibitors on female reproduction

Targeted cancer therapy is rapidly evolving the landscape of personalized health care. Novel approaches to selectively impeding tumour growth carry significant potential to improve survival outcomes, particularly for reproductive-aged patients harbouring treatment refractory disease. Current agents fall within two classes: immunotherapy and small molecule inhibitors. These are collectively divided into the following subclasses: monoclonal antibodies; immunomodulators; adoptive cell therapy; treatment vaccines; kinase inhibitors; proteasome inhibitors; metalloproteinase and heat shock protein inhibitors; and promoters of apoptosis. The short- and long-term effects of these treatments on the female reproductive system are not well understood. As a result, clinicians are rendered unable to appropriately counsel women on downstream effects to their fertility. Data-driven consensus recommendations are desperately needed. This review aims to characterize the effect of targeted cancer therapy on the female hypothalamic-pituitary-ovary axis, direct ovarian function and conception.

Human Granulosa Cells-Stemness Properties, Molecular Cross-Talk and Follicular Angiogenesis

The ovarian follicle is the basic functional unit of the ovary, comprising theca cells and granulosa cells (GCs). Two different types of GCs, mural GCs and cumulus cells (CCs), serve different functions during folliculogenesis. Mural GCs produce oestrogen during the follicular phase and progesterone after ovulation, while CCs surround the oocyte tightly and form the cumulus oophurus and corona radiata inner cell layer. CCs are also engaged in bi-directional metabolite exchange with the oocyte, as they form gap-junctions, which are crucial for both the oocyte’s proper maturation and GC proliferation. However, the function of both GCs and CCs is dependent on proper follicular angiogenesis. Aside from participating in complex molecular interplay with the oocyte, the ovarian follicular cells exhibit stem-like properties, characteristic of mesenchymal stem cells (MSCs). Both GCs and CCs remain under the influence of various miRNAs, and some of them may contribute to polycystic ovary syndrome (PCOS) or premature ovarian insufficiency (POI) occurrence. Considering increasing female fertility problems worldwide, it is of interest to develop new strategies enhancing assisted reproductive techniques. Therefore, it is important to carefully consider GCs as ovarian stem cells in terms of the cellular features and molecular pathways involved in their development and interactions as well as outline their possible application in translational medicine.

The Role of the Guanosine Nucleotide-Binding Protein in the Corpus Luteum

Simple Summary

This review aims to discuss the role of the guanosine nucleotide-binding protein (RAS) family in the biological events that occur during the formation and regression of the corpus luteum in the ovary. RAS proteins mediate extracellular signals, transduce through their receptors via multiple signaling pathways, and regulate a wide array of cellular processes. RAS exhibits a notable function in the regulation of vascular endothelial growth factor, fibroblast growth factor, insulin-like growth factor, angiopoietins (ANPT), and hypoxia-inducible factor (HIF). RAS proteins appear to be involved in several factors that are notably associated with the regulation of the corpus luteum. Further research is necessary to enhance our understanding of the role of the RAS family in the ovarian corpus luteum.

Abstract

The corpus luteum is a temporary endocrine gland in the ovary. In the ovarian cycle, repeated patterns of specific cellular proliferation, differentiation, and transformation occur that accompany the formation and regression of the corpus luteum. Molecular mechanism events in the ovarian microenvironment, such as angiogenesis and apoptosis, are complex. Recently, we focused on the role of RAS protein in the ovarian corpus luteum. RAS protein plays a vital role in the modulation of cell survival, proliferation, and differentiation by molecular pathway signaling. Additionally, reproductive hormones regulate RAS activity in the cellular physiological function of ovarian follicles during pre-ovulatory maturation and ovulation. Thus, we have reviewed the role of RAS protein related to the biological events of the corpus luteum in the ovary.

Significance of pro-angiogenic estrogen metabolites in normal follicular development and follicular growth arrest in polycystic ovary syndrome

STUDY QUESTION

Do alterations in pro- and anti-angiogenic estrogen metabolites in follicular fluid (FF) contribute to the follicular growth arrest and anovulation associated with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

FF of PCOS women with anovulation have reduced levels of pro-angiogenic estrogen metabolites (EMs) and vascular endothelial growth factor (VEGF) compared to that of fertile women with regular menstrual cycles, but exogenous gonadotropins increase the pro-angiogenic EMs and VEGF levels in PCOS women.

WHAT IS KNOWN ALREADY

PCOS is characterized by the arrest of follicular development that leads to chronic anovulation. Follicular arrest is generally associated with elevated plasma levels of luteinizing hormone (LH), androgens and anti-Mullerian hormone (AMH). There is also reduced angiogenesis in the follicles of PCOS women compared to those of normal cycling women. It is known that angiogenesis is a critical factor during follicular development. We and other investigators have explored the role of EMs in ovarian angiogenesis, particularly in human corpus luteum function, showing that 4-hydroxyestrone (4-OHE1) and 16-ketoestradiol (16-kE2) have pro-angiogenic effects while 2-methoxyestradiol (2-ME2) and 2-methoxyestrone (2-ME1) have anti-angiogenic effects. Additionally, 2-hydroxyestradiol (2-OHE2), which is produced in the ovary, has proliferative and pro-angiogenic properties. We hypothesized that EMs could be involved in angiogenesis necessary for ovarian follicular development in fertile women, and that dysregulation of these factors may contribute to follicular arrest in PCOS. The relationship between EMs, VEGF and AMH in the pathophysiology of follicular arrest in PCOS has not been previously studied at a follicular level in anovulatory women without ovulation induction.

STUDY DESIGN, SIZE, DURATION

This is a comparative experimental study of serum and FF collected from different sized follicles (antral ˂10 mm and dominant ˃16 mm) of women with and without ovarian stimulation. The study included women with regular menstrual cycles who were proven to be fertile (n = 20) and PCOS women with follicular arrest who were candidates for ovarian drilling (n = 17), as well as other patients requiring ovarian stimulation, i.e. control women undergoing IVF for male factor infertility (n = 12) and PCOS women undergoing IVF (n = 17). In vitro studies were carried out on granulosa-lutein cells (GCs) obtained from subsets of women undergoing IVF for male factor infertility (n = 6) and PCOS women undergoing IVF (n = 6). GCs were maintained in culture for up to 6 days.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Intrafollicular estradiol, estrone and EMs concentrations were determined by high performance liquid chromatography-mass spectrometry. Testosterone in serum was measured by RIA, and LH, FSH and sex hormone-binding globulin in serum were measured with IRMA kits. AMH was determined in serum and FF by enzyme linked immunosorbant assay (ELISA). VEGF levels were measured in FF and conditioned medium by ELISA. Conditioned medium were obtained from cultured GCs. The angiogenic potential was assessed by in vitro angiogenic assays.

MAIN RESULTS AND THE ROLE OF CHANCE

Pro-angiogenic EMs (4-OHE1, 16-kE2 and 2-OHE2) and VEGF were lower in FF of antral follicles of PCOS women with follicular arrest compared those of fertile women with ovulatory cycles (P < 0.05). In contrast, higher concentrations of AMH were found in FF of antral follicles from PCOS women with follicular arrest compared to those of fertile women with ovulatory cycles (P < 0.05). Exogenous gonadotropins used in IVF increased pro-angiogenic EMs and VEGF production in PCOS women, reaching similar profiles compared to control women receiving gonadotropins in their IVF treatment for male factor infertility. The pro-angiogenic EM 2-OHE2 increased the angiogenic potential and VEGF levels of GCs from PCOS women compared to the basal condition (P < 0.05). These findings suggest that there is a role for pro-angiogenic EMs in the control of follicular VEGF production.

LIMITATIONS, REASONS FOR CAUTION

The limitations include the possibility that in vitro analysis of GCs might not reflect the in vivo mechanisms involved in the pro-angiogenic action of 2-OHE2 since GCs obtained at the time of oocyte retrieval belong to a very early stage of the luteal phase and might not be representative of GCs during follicular growth. Therefore, our findings do not conclusively rule out the possibility that other in vivo mechanisms also account for defective angiogenesis observed in PCOS.

WIDER IMPLICATIONS OF THE FINDINGS

The present study highlights the significance of EMs, angiogenic factors and AMH and their interaction in the pathophysiology of follicular development in PCOS. This study provides new insights into the role of pro-angiogenic factors in follicular arrest in PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by CONICYT/FONDECYT 1140693 and NIH grant R01HD083323. All authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Heterogeneity and Dynamics of Vasculature in the Endocrine System During Aging and Disease

The endocrine system consists of several highly vascularized glands that produce and secrete hormones to maintain body homeostasis and regulate a range of bodily functions and processes, including growth, metabolism and development. The dense and highly vascularized capillary network functions as the main transport system for hormones and regulatory factors to enable efficient endocrine function. The specialized capillary types provide the microenvironments to support stem and progenitor cells, by regulating their survival, maintenance and differentiation. Moreover, the vasculature interacts with endocrine cells supporting their endocrine function. However, the structure and niche function of vasculature in endocrine tissues remain poorly understood. Aging and endocrine disorders are associated with vascular perturbations. Understanding the cellular and molecular cues driving the disease, and age-related vascular perturbations hold potential to manage or even treat endocrine disorders and comorbidities associated with aging. This review aims to describe the structure and niche functions of the vasculature in various endocrine glands and define the vascular changes in aging and endocrine disorders.

Hypoxia up-regulates VEGF ligand and downregulates VEGF soluble receptor mRNA expression in bovine granulosa cells in vitro

Oxygen concentration (0₂) in antral ovarian follicles is below that found in most tissues, which is important for adequate granulosa cell function. The VEGF system is linked to angiogenesis and responds to changing 0₂ by stimulating neovascularization when levels are low. However, in the avascular granulosa cell layer of the follicle, VEGF action is directed to stimulating cell viability and steroidogenesis. The aim of this study was to examine the effect of 0₂ concentration on granulosa cell expression of the VEGF-system components. Bovine granulosa cells were isolated from medium-sized follicles (4-7 mm in diameter), placed in McCoy 5a medium supplemented with 10 ng/mL of insulin, 1 ng/mL of IGF-I, and 1 ng/mL of FSH, and cultured in four well plates (500 thousand cells per well), on three separate occasions. Culture plates were placed in gas-impermeable jars with a gas mixture containing either 2%, or 5% of O₂, or under atmospheric air condition inside an incubator (20% of 0₂). Media was replaced at 48 h of culture and cells from the plate in each oxygen concentration were pooled for RNA extraction after 96 h. The number of mRNA copies for the VEGF-system components - including ligands (VEGF120, VEGF120b, VEGF165 and VEGF165b), enzymes (cyclin-dependent like kinases-1, CLK1 and serine-arginine protein kinase 1, SRPK1), splicing factors (serine-arginine-rich splicing factors, SRSF1 and SRSF6), and the membrane-bound (VEGFR1, VEGFR2) and soluble forms of the receptors (sVEGFR1 and sVEGFR2) were quantified by qPCR. Granulosa cells cultured with low 0₂ (2%) had a higher expression of VEGF ligands (P < 0.05) when compared to cells cultured at 20% 0₂. VEGF164b mRNA was absent in granulosa cells from all culture conditions. The 2 and 5% 0₂ levels, which coincide with physiological concentrations, in the ovarian follicle, induced higher SRSF6 expression than atmospheric 0₂ concentrations (20%, P < 0.05). In contrast, mRNA copies for SRPK1, CLK1, SRSF1, VEGFR1 or VEGFR2 did not differ between 0₂ culture conditions. (P > 0.05). Nonetheless, mRNA copies for the soluble receptors, sVEGFR1 and sVEGFR2, linearly increased (P < 0.05) with 0₂ concentration. These results suggest that when cultured under hypoxic conditions, granulosa cells may develop an autocrine milieu that favors VEGF's biological effects on their survival and function.

Effect of Different Concentrations of Leukemia Inhibitory Factor on Gene Expression of Vascular Endothelial Growth Factor-A in Trophoblast Tumor Cell Line

Background

Several studies have shown that leukemia inhibitory factor (LIF) is one of the most important cytokines participating in the process of embryo implantation and pregnancy, while, the role of this factor on vascular endothelial factor-A (VEGF-A), as one of the most important angiogenic factor, has not been fully investigated yet. The aim of this study was to evaluate the effect of LIF on gene expression of VEGF in the choriocarcinoma cells (JEG-3).

Materials and Methods

In this experimental study, JEG-3 choriocarcinoma cells were treated with different concentrations of LIF (1, 10, and 50 ng) for 6, 12, 24, 48 and 72 hours. Expression of VEGF was analyzed by real-time PCR. Delta CTs were subjected to one-way analysis of variance (ANOVA) and a post hoc Tukey's test by SPSS version 25.0 software for data analyzing.

Results

In the stimulated cells, different concentrations of LIF caused significant decrease of VEGF gene expression (P<0.05) at 12, 24 and 48 hours. In contrast, it was increased after 72 hours (P<0.001). Analysis of data after 6 hours also showed that level of VEGF gene expression was significantly decreased by increasing LIF concentration (P<0.001).

Conclusion

Expression level of VEGF gene was decreased in trophoblast cells (except after 72 hours) under the effect of different concentrations of LIF in a time-dependent manner. So, this study showed that further studies are needed to determine the effect of LIF on other angiogenic factors in trophoblast cells.

Low oxygen concentrations improve yak oocyte maturation and enhance the developmental competence of preimplantation embryos

Mammalian oocyte maturation and early embryo development are highly sensitive to the in vitro culture environment, and oxygen concentration is one of the important factors. In the present study, we aimed to explore the effects of different oxygen concentrations (20%, 10%, 5% or 1% O₂) on yak oocyte maturation, in vitro fertilization (IVF), and embryo development competence, as well as its effects on the oxidative response, metabolism, and apoptosis in cumulus-oocyte complexes (COCs) and the embryo. The results revealed that the maturation rate of oocytes, blastocysts rate and hatched blastocysts rate in the group with 5% oxygen concentration were significantly higher (P < 0.05) than other groups, but the cleavage rate with 5% oxygen concentration was significantly lower (P < 0.05) than the 20% and 10% oxygen concentrations. The maturation rate of oocytes, the cleavage rate, blastocysts rate and hatched blastocysts rate with the 1% oxygen concentration were the lowest. The blastocyst cultured with 5% oxygen concentration had significantly greater (P < 0.05) numbers of total cells, inner cell mass (ICM) cells and trophectoderm (TE) cells compared to the other groups. Analysis of the apoptosis index of oocytes and blastocyst cells by transferase dUTP nick end labeling (TUNEL) showed that the number of apoptotic cells significantly reduced (P < 0.05) with 5% oxygen concentration, but increased significantly (P < 0.05) in the 1% oxygen concentration group. Also, the qRT-PCR and western immunoblotting analysis confirmed that the transcription levels of the metabolism genes, antioxidant response genes, apoptosis genes, oocyte competence genes and embryonic developmental markers showed significant differences (P < 0.05) in the COCs or blastocysts matured in 5% oxygen concentration group compared to the other groups. In summary, our findings demonstrate that 5% oxygen concentration improves oocyte maturation and blastocyst development in the yak, increases blastocyst cell numbers, reduces apoptosis rate in the oocyte and blastocyst as well as reduces embryo cleavage rate.

Ruptured hemorrhagic corpus luteum as a presenting symptom of systemic lupus erythematous

A young female presented to the emergency room with ruptured hemorrhagic corpus luteum (RHCL). Her workup revealed a new diagnosis of SLE with nephritis and positive lupus anticoagulant (LAC) test without thrombocytopenia. We reviewed the literature and found one similar case of a 23-year-old subject who presented with a RHCL that was found to be the presenting symptom of SLE; unlike the current case, the patient presented with severe anemia (Hg 6.7 g/dl) and thrombocytopenia (10,000/ml). Possible mechanisms are discussed.

Involvement of JNK/FOXO1 pathway in apoptosis induced by severe hypoxia in porcine granulosa cells

In ovaries, follicles undergo a periodic process of degeneration, namely atresia, during each stage of development. Granulosa cell (GC) apoptosis is believed as the hallmark of follicular atresia. The avascular environment within the granulosa compartment is supposed to cause hypoxic conditions. The effects of hypoxia on organs, tissues, cells can be either positive or negative, depending on the severity and context. The present study aimed to explore whether and how severe hypoxia under in vitro conditions functions in apoptosis of porcine GCs. The current results showed that the apoptosis in porcine GCs exposed to severe hypoxia (1% O₂) was correlated with enhanced activation of c-Jun N-terminal kinase (JNK), nuclear accumulation of FOXO1, as well as elevated level of cleaved caspase-3 and decreased ratio of BCL-2/BAX. Further investigations revealed that severe hypoxia-mediated JNK activation was required for the apoptotic death of porcine GCs and the nuclear transport of FOXO1. Moreover, inhibition of FOXO1 reduced GCs apoptosis upon severe hypoxia exposure. Together, these findings suggested that severe hypoxia might act through JNK/FOXO1 axis to induce apoptosis in porcine GCs.

Adrenomedullin expression in aortic artery wall of diabetic rats given alpha lipoic acid

BACKGROUND

Diabetes mellitus (DM) is a major health problem predisposing to cardiovascular diseases. The aim of this study was to investigate the effects of alpha lipoic acid (ALA) on both the arterial wall of diabetic rats and the adrenomedullin (ADM) gene expression.

METHODS

Twenty-four Wistar Albino rats were divided into three groups as Control, DM + S, and DM + ALA. For DM model, a single dose of 40 mg/kg streptozotocin, for DM + ALA group, 100 mg/kg/day/4 weeks was administered. Hematoxylin & Eosin (H&E) staining was done and vascular endothelial growth factor (VEGF) was detected by immunohistochemical analysis in the artery wall. Total damage score of vessel wall (endothelial cell damage, media layer smooth muscle cell damage, and internal elastic lamina damage) and H score (immunoreactivity intensity) were calculated. Expression of ADM gene was measured by qRT-PCR.

RESULTS

In DM + S group, Total damage score of vessel wall were detected by light microscopy. There were statistically significant differences between the groups Control/DM + S and DM + S/DM + ALA in terms of the vessel total damage score and H score (p < 0.005). ADM expression was increased threefold in both DM + S and DM + ALA groups compared to the control group (p < 0.05).

CONCLUSIONS

ALA may have positive effect on the vessel damage in diabetic rats. However, no significant decrease in ADM expression levels was observed in diabetic rats after ALA administration and we considered that the protective effect of ALA is independent of adrenomedullin. Further studies with different doses and durations of ALA administrations are required to investigate the changes in ADM expression.

Deficiency in proliferative, angiogenic, and LH receptors in the follicle wall: implications of season toward the anovulatory condition

This study aimed to gain insight on the effect of different seasons of the year on the expression pattern of growth factor and hormone receptors involved in follicle development. A novel follicle wall biopsy technique was used to collect in vivo follicle wall layers (ie, granulosa, theca interna, and theca externa) and follicular fluid samples from growing dominant follicles, simultaneously and repeatedly, using the same mares during the spring anovulatory (SAN), spring ovulatory (SOV), summer (SU), and fall ovulatory (FOV) seasons. The immunofluorescent expression patterns of epidermal growth factor receptor (EGFR), Ki-67, vascular endothelial growth factor receptor (VEGFR), and LH receptor (LHR) were evaluated in each follicle wall layer, in addition to intrafollicular estradiol and nitric oxide (NO). Proliferative proteins (EGFR and Ki-67) were highly (P < 0.05-P < 0.001) expressed during the SOV season compared with the SAN and FOV seasons. Lower (P < 0.05-P < 0.001) expression of both proteins was observed during SU compared with the SOV season. The expression of VEGFR was greater (P < 0.05-P < 0.01) in the theca interna of dominant follicles during the SOV season compared with the SAN and SU seasons. Similarly, in the overall quantification, the VEGFR expression was greater (P < 0.001) during the SOV season compared with the SU and FOV seasons. A higher (P < 0.05) LHR expression was detected in the theca interna during the SOV season than the SAN season. Furthermore, a higher (P < 0.05-P < 0.001) expression of LHR was observed in the granulosa, theca interna, and in the overall quantification during the SOV season compared with the SU and FOV seasons. Intrafollicular NO concentration did not differ (P > 0.05) among different seasons of the year. The intrafollicular estradiol concentration was higher (P < 0.05) during the SU compared with the SAN season and higher (P < 0.05) during the FOV season compared with the SAN and SOV seasons. In conclusion, the synergistic effect of lower expression of proliferative protein, angiogenic, and LH receptors in at least some of the layers of the follicle wall seems to trigger dominant follicles toward the anovulation process during the spring and fall transitional seasons.

Transition to the ovulatory season in mares: An investigation of antral follicle receptor gene expression in vivo

The inability to obtain in vivo samples of antral follicle wall layers without removing the ovaries or sacrificing the animals has limited more in-depth studies on folliculogenesis. In this study, a novel ultrasound-guided follicle wall biopsy (FWB) technique was used to obtain in vivo follicle wall layers and follicular fluid samples of growing antral follicles. The expression of proliferative, hormonal, angiogenic, and pro-/antiapoptotic receptors and proteins in the follicular wall among three follicle classes were compared during the spring transitional anovulatory (SAN) and spring ovulatory (SOV) seasons in mares. The main findings observed in the granulosa, theca interna, and/or all follicle layers during the SOV season compared with the SAN season were (a) small-sized follicles (10-14 mm) had greater epidermal growth factor receptor (EGFR) and Bcl-2 expression; (b) medium-sized follicles during the expected deviation/selection diameter (20-24 mm) had greater expression of EGFR, Ki-67, luteinizing hormone receptor (LHR), and Bcl-2; and (c) dominant follicles (30-34 mm) had greater EGFR, Ki-67, vascular endothelial growth factor, LHR, and Bcl-2 expression. Estradiol related receptor alpha expression and intrafollicular estradiol concentration increased, along with an increase in follicle diameter in both seasons. In this study, the application of the FWB technique allowed a direct comparison of different receptors' expression among follicles in different stages of development and between two seasons using the same individuals, without jeopardizing their ovarian function. The successful utilization of the FWB technique and the mare as an experimental animal offer a great combination for future folliculogenesis studies on mechanisms of follicle selection, development, and ovulation in different species, including women.

Ethiopathogenic mechanisms of endometriosis-related infertility

Endometriosis is a highly prevalent disease among women of reproductive age and is frequently associated to infertility. However, the mechanisms underlying endometriosis-related infertility are still not completely known. Several studies have been conducted in order to elucidate this question. Besides anatomical changes that may impair gametes and embryo transport along the tubes; a smaller ovarian reserve due to advanced endometriosis and endometriomas; and a dysregulated hypothalamic-pituitary-ovarian axis, there are pieces of evidence suggesting that the peritoneal ectopic endometrial foci may induce a local inflammatory response, with the recruitment of macrophages, cytokine release, and reactive oxygen species generation, leading to a pro-oxidant peritoneal microenvironment. These alterations may be systemically reflected and also affect the follicular microenvironment. A harmful follicular fluid may disrupt cumulus cells functions and, consequently, compromise oocyte competence. There is also evidence suggesting that the peritoneal fluid of women with endometriosis may alter sperm function. Reduced endometrial receptivity is also pointed as a possible mechanism involved in endometriosis-related infertility, which needs further investigation.

The Role of Blood Flow in Corpus Luteum Measured by Transvaginal Two-Dimensional and Three-Dimensional Ultrasound in the Prediction of Early Intrauterine Pregnancy Outcomes

Objective: The purpose of this study was to explore the application of transvaginal two-dimensional and three-dimensional power Doppler ultrasound in pregnancy corpus luteum to predict the final outcome of early intrauterine pregnancy.

Methods: This is a prospective observational cohort study. Six hundred early intrauterine pregnant women in Shanghai Changning Maternity and Infant Health Hospital were selected as the research objects from January 2015 to December 2015. According to the follow-up of 12 weeks, these pregnant women were divided into the normal pregnancy group (group A, n = 512) and the terminational pregnancy group (group B, n = 88). They all underwent both transvaginal two-dimensional ultrasound and three-dimensional power Doppler ultrasound to obtain relevant parameters of corpus luteum, namely, the average diameter of the corpus luteum (D), resistance index (RI), pulsatility index (PI), corpus luteum volume (V), vascularization index (VI), blood flow index (FI), and vascularized blood flow index (VFI). Among them, V, VI, FI, and VFI were calculated with the virtual organ computer-aided analysis method. Receiver operator characteristic (ROC) curves were drawn. The corresponding diagnostic cut-off, sensitivity, and specificity were calculated and compared.

Results: Compared with group A, the D, V, VI, FI, and VFI of corpus luteum in group B were statistically significant lower while RI and PI were statistically significant higher (P < 0.05). The diagnostic cut-off values in the prediction of early intrauterine pregnancy outcomes were D: 14.48, RI: 0.56, PI: 0.81, V: 3.89, VI: 21.48, FI: 38.99, and VFI: 10.21 respectively, and the sensitivity and specificity were D (99.2%, 67.0%), RI (98.9%, 65.0%), PI (78.4%, 89.1%), V (95.1%, 78.4%), VI (74.%, 90.9%), FI (91.8%, 90.9%), and VFI (93.9%, 87.5%) respectively. The area under the ROC curve of the combined index (RI + FI) was 0.963, which was not significantly higher compared with any single index, and both the sensitivity and specificity were 94.3%.

Conclusion: Both transvaginal two-dimensional and three-dimensional ultrasonography are of high diagnostic value in predicting the early intrauterine pregnancy outcomes.

Ovulation induction in anovulatory southern white rhinoceros (Ceratotherium simum simum) without altrenogest

All species in the extant Rhinocerotidae family are experiencing increased threats in the wild, making captive populations essential genetic reservoirs for species survival. However, managed species face distinct challenges in captivity, resulting in populations that are not self-sustaining. Captive southern white rhinoceros (Ceratotherium simum simum) have low reproductive rates and presumed acyclicity is common among females. Although many females fail to ovulate, follicle growth may occur and ovulation can be hormonally induced. Female southern white rhino (n = 6), housed as a bachelorette group, were determined to be ovulatory (n = 1) or anovulatory (n = 5) by serial ultrasound and fecal progestagen analysis. When follicles reached pre-ovulatory size (~35 mm), females (n = 4) were induced to ovulate in 11 trials with a GnRH analog (4.5 mg, SucroMate™) via single intramuscular injection. Nine trials resulted in ovulation (81.8%), all between 36 and 48 hours post-treatment. Ovulations were confirmed by progestagen elevation above baseline coincident with visualization of a corpus luteum (CL). Luteal phases were characterized as short (<50 days) or long (≥50 days). Between short and long cycles, only the number of days of progestagen above baseline was significantly different (P < 0.05), while days with visible luteal structures was not significant (P = 0.11). Both cycle types were observed following both spontaneous and induced ovulations. Furthermore, we showed that longer cycle lengths do not necessarily indicate early pregnancy loss as none of the females were bred or inseminated during the study. While anovulation is common in the southern white rhino captive population, ovulation induction can be achieved efficiently and predictably for use in conjunction with artificial insemination or to facilitate natural breeding. This information will lead to more efficient use of assisted reproductive technologies to overcome reproductive challenges in this species and to generate genetically healthy captive populations as a hedge against extinction.

Early pregnancy diagnosis by semiquantitative evaluation of luteal vascularity using power Doppler ultrasonography in sheep

The aim of the study was to measure the area of coloured pixels captured in power Doppler examination of corpus luteum (CL) by a computer-assisted image analysis software and to evaluate the efficiency of the semiquantitative assessment of CL in early pregnancy diagnosis in sheep. Assessment of luteal vascularity was carried out on 30 Kivircik ewes with power Doppler ultrasonography daily from Day 12 to Day 19 post breeding. The mean area of coloured pixels of CL with pregnancy was found significantly higher than the area of coloured pixels of CL undergoing luteolysis (0.38 ± 0.012 mm2 and 0.31 ± 0.017 mm2, respectively, P < 0.001). Assessment of day-based examination showed a significant difference between the area of coloured pixels of CL with continuing pregnancy and luteolysis on Day 17 (P < 0.05), which was followed by Days 18 and 19 (P < 0.001). It is concluded that pregnancy diagnosis can be done accurately by semiquantitative assessment of luteal vascularization as early as 17 days post breeding in ewes. According to the authors’ knowledge, this is the first report on the efficacy of semiquantitative assessment of ovine CL in early pregnancy diagnosis.

Intra-ovarian dynamic blood flow in pseudopregnant rabbits during prostaglandin F2α-induced luteolysis

In the present study, we evaluated the dynamic changes of intra-ovarian blood flow, by real-time colour-coded and pulsed Doppler ultrasonography, as well as the immunopresence of prostaglandin F2α (PGF2α) receptor (FP) and peripheral plasma progesterone concentrations in pseudopregnant rabbit after PGF2α treatments at either early- (4 days) and mid-luteal (9 days) stages. During the pre-treatment observation interval of one hour, the ovarian blood flows showed a fluctuating pattern. Independently of luteal stage, PGF2α administration caused a fourfold decline in the blood flow within 40 min that was followed 50 min later by a reactive hyperaemia that lasted several hours, while the resistive index showed an opposite trend. Twenty-four hour later, the blood flow was one half that measured before PGF2α injection. At day 4 of pseudopregnancy, PGF2α did not affect peripheral plasma progesterone concentrations, but at day 9, it caused functional luteolysis as progesterone levels declined 6 hr later to reach basal values after 24 hr. The changes in the ovarian blood flows of pseudopregnant rabbits receiving PGF2α were accompanied by simultaneous changes in the resistance index. This biphasic response in the blood flow and vascular resistances likely reflects reactive hyperaemia following vasoconstriction. By immunohistochemistry, strong positive immune reaction for FP was detected in the cytoplasm of endothelial cells of ovarian arteries, veins and capillaries. In conclusion, these results suggest that PGF2α could acutely regulate the ovarian blood flow of pseudopregnant rabbits, even if there is no evidence of a blood flow reduction anticipating luteolysis.

Synergy of Paracrine Signaling During Early-Stage Mouse Ovarian Follicle Development In Vitro

Introduction

Paracrine signals, such as soluble cytokines and extracellular matrix cues, are essential for the survival and development of multicellular ovarian follicles. While it is well established that hydrogel-based culture systems successfully support the growth of late-stage follicles for fertility preservation, growing small, early-stage ovarian follicles still proves to be challenging. We hypothesized that paracrine factors secreted from neighboring follicles may be crucial for improving the survival of early-stage follicles in vitro.

Methods

To test our hypothesis, we investigated the bi-directional crosstalk of the paracrine signals, such as cell-secreted cytokines, sex hormones and transcription factors (TFs), in follicles encapsulated and cultured for 12 days in alginate in groups of five (5×) and ten (10×).

Results

The differential profiles of TF activity and secretome during folliculogenesis were analyzed using TRanscriptional Activity CEllular aRray (TRACER) and data-driven multivariate modeling approach. The mechano- and oxygen-responsive TFs, NF-κB and HIF1, exhibited a unique upregulation signature in 10× follicles. Consistently, levels of proangiogenic factors, such as VEGF-A and angiopoietin-2, were significantly higher in 10× follicles than those in 5× follicles, reaching 269.77 and 242.82 pg/mL on the last day of culture. The analysis of TRACER and secreted cytokines also revealed critical early interactions between cytokines and TFs, correlating with the observed phenotypical and functional differences between conditions.

Conclusions

We identified unique signatures of synergism during successful early-stage ovarian follicle development. These findings bring us closer to understanding of mechanisms underlying the downstream effects of interactions between the extracellular microenvironment and early-stage folliculogenesis in vitro.

Influence of follicular fluid and cumulus cells on oocyte quality: clinical implications

An equilibrium needs to be established by the cellular and acellular components of the ovarian follicle if developmental competence is to be acquired by the oocyte. Both cumulus cells (CCs) and follicular fluid (FF) are critical determinants for oocyte quality. Understanding how CCs and FF influence oocyte quality in the presence of deleterious systemic or pelvic conditions may impact clinical decisions in the course of managing infertility. Given that the functional integrities of FF and CCs are susceptible to concurrent pathological conditions, it is important to understand how pathophysiological factors influence natural fertility and the outcomes of pregnancy arising from the use of assisted reproduction technologies (ARTs). Accordingly, this review discusses the roles of CCs and FF in ensuring oocyte competence and present new insights on pathological conditions that may interfere with oocyte quality by altering the intrafollicular environment.

Fertility rescue and ovarian follicle growth promotion by bone marrow stem cell infusion

OBJECTIVE

To assess if infusion of human bone marrow-derived stem cells (BMDSCs) could promote follicle development in patients with impaired ovarian functions.

DESIGN

Experimental design.

SETTING

University research laboratories.

ANIMAL(S)

Immunodeficient NOD/SCID female mice.

INTERVENTION(S)

Human BMDSCs were injected into mice with chemotherapy-induced ovarian damage and into immunodeficient mice xenografted with human cortex from poor-responder patients (PRs).

MAIN OUTCOME MEASURE(S)

Follicle development, ovulation, and offspring. Apoptosis, proliferation, and vascularization were evaluated in mouse and human ovarian stroma.

RESULT(S)

Fertility rescue and spontaneous pregnancies were achieved in mice ovaries mimicking PRs and ovarian insufficiency, induced by chemotherapy, after BMDSC infusion. Furthermore, BMDSC treatment resulted in production of higher numbers of preovulatory follicles, metaphase II oocytes, 2-cell embryos, and healthy pups. Stem cells promoted ovarian vascularization and cell proliferation, along with reduced apoptosis. In xenografted human ovarian tissues from PRs, infusion of BMDSCs and their CD133+ fraction led to their engraftment close to follicles, resulting in promotion of follicular growth, increases in E₂ secretion, and enhanced local vascularization.

CONCLUSION(S)

Our results raised the possibility that promoting ovarian angiogenesis by BMDSC infusion could be an alternative approach to improve follicular development in women with impaired ovarian function.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02240342.

Corpus luteum dynamics after ovulation induction with or without previous exposure to progesterone in prepubertal Nellore heifers

The objectives of this study were 1) to monitor corpus luteum (CL) dynamics after two different protocols of ovulation induction in prepubertal Nellore heifers, and 2) to determine differences in luteal function. Fifty-seven heifers (weight 289.61 ± 32.28 kg, BCS 5.66 ± 0.65, age 17.47 ± 0.81 months) were divided into two groups: GP4+GnRH received a progesterone (P4) device of 3rd use for 10 days, followed by the administration of 0.02 mg buserelin acetate (GnRH) 48 h after removal of the device, and GGnRH received only GnRH. The CLs formed were monitored by ultrasonography every 2 days until their functional regression (decrease in the color Doppler signal and serum P4 concentration < 1 ng/mL), determining their diameter and area, numerical pixel value (NPV), pixel heterogeneity, and vascularization percentage. The peak systolic velocity, end diastolic velocity, resistivity index and pulsatility index (PI) of the ovarian artery and serum P4 concentration were also measured. A lifespan of the CL of more than 16 days was classified as normal-function and of less than 16 days as premature regression. The variables were compared between treatments, CL categories (normal-functional, prematurely regressed or non-functional), days of evaluation, and their interactions using the MIXED procedure of the SAS program (p ≤ 0.05). Three animals of each group (6/57 = 11%) did not respond to treatment, corresponding to an ovulation rate of 89%. There was a higher percentage of normal-function CLs in GP4+GnRH (81%) and a higher percentage of non-functional CLs in GGnRH (52%; P4 concentration < 1 ng/mL in all assessments). Normal-function CLs exhibited a greater area, vascularization percentage and P4 concentration than prematurely regressed and non-functional CLs. Lower diameter, area, NPV and P4 concentration were observed for non-functional CLs, but there was no difference in vascularization percentage compared to prematurely regressed CLs. Progesterone concentration was efficient in diagnosing CL function and was positively correlated with CL area (r = 0.62; p < 0.001) and vascularization percentage (r = 0.38; p < 0.001). Diameter and PI were important for the early diagnosis of non-functional and prematurely regressed CLs, respectively. In conclusion, luteal function differed for the first CL that develops after ovulation induction in prepubertal heifers. Ultrasonographic parameters (diameter, area, NPV, vascularization percentage, and PI) can be used to predict CL function.

Diabetes Induces Abnormal Ovarian Function via Triggering Apoptosis of Granulosa Cells and Suppressing Ovarian Angiogenesis

Diabetes triggers abnormal ovarian follicular development and consequently leads to infertility. Here, we established a type 2 diabetes mouse model by feeding with high fat diet (HFD) for 15/20 weeks and assessed the effect of diabetes on follicular development and ovarian angiogenesis. After fed with HFD for 15 weeks, mice had the characteristics of type 2 diabetes, which was much more serious after 20 weeks on HFD. After 20 weeks on HFD, the mice had shown abnormal ovarian morphology with hyaline appearance, much less blood vessel, follicular development arrest and less of granulosa cells (GCs) in mature follicles, but not in ovaries from 15 weeks on HFD. Elevated makers of DNA damage, ER stress and apoptosis of GCs were observed in ovaries from HFD for 20 weeks. Additionally, diabetes significantly suppressed ovarian angiogenesis with the evidence of down-regulation of CD31 via inhibiting HIF1α-VEGF signaling pathway in time-dependent. We concluded that diabetes triggers abnormal ovarian function via inducing GCs apoptosis and suppressing ovarian angiogenesis.

The presence of VEGF and Notch2 during preantral-antral follicular transition in infantile rats: Anatomical evidence and its implications

Folliculogenesis is a process that depends on angiogenesis, in which VEGF and Notch signaling pathway members are involved. Although this pathway is present in preantral and antral follicular structures during the second stage of folliculogenesis, this association has not been described. Therefore, this study aimed to identify VEGF and Notch2 in ovary structures of infantile rats after induction of follicular development with a gonadotropin stimulus. In order to explore this possibility we analyzed rat ovary morphology from days 10-25 after birth; subsequently, the transition from preantral follicle to an antral stage was analyzed by the induction of follicular development with equine chorionic gonadotropin (eCG) and VEGF and Notch were identified in the rat ovary by fluorescence. The histological analysis revealed that the ovary of a 10-day-old rat has the highest percentage of preantral follicles and based on this a 10IU eCG dose promoted an increase in the number of antral follicles, as well as a decrease in the number of preantral follicles, related to which there was an increase in ovary weight and size. In addition, a higher concentration of circulating estradiol was observed, proliferation of granulosa cells in both follicle groups was stimulated, and the accumulation of VEGF in granulosa and theca cells and in the antral follicle oocyte was increased (p<0.05), whereas the presence of Notch2 was limited to mural granulosa cells, in granulosa cells that formed the cumulus oophorus and in the oocyte of both groups of follicles. The multiple correspondence analysis allowed us to support an association between VEGF and Notch2 during the transition from preantral to antral follicles in the ovary of an infantile rat.

Tankyrase inhibition regulates corpus luteum development and luteal function in gonadotropin-treated rats

Tankyrases are physiological regulators of Axin, a protein involved in several cellular processes, including Wnt signaling. Here, we investigated the effect of a specific Tankyrase inhibitor (XAV939) in follicular-luteal dynamics, and its possible relationship with ovarian vascular development. Studies were designed to analyze the effect of intrabursa administration of XAV939 in gonadotropin-treated prepubertal rats. In particular, we examined follicle and corpus luteum development, steroidogenesis, angiogenic markers, and apoptotic parameters. We found that in vivo inhibition of Wnt signaling impaired corpus luteum development, with a decrease in the number of corpora lutea balanced by a high number of cysts; decreased circulating progesterone levels, likely due to a decrease in Steroidogenic acute regulatory protein content in the corpus luteum; and increased pro-apoptotic parameters. In addition, Extracellular signal-regulated kinase phosphorylation, Vascular endothelium growth factor 120 content, and endothelial cell area were diminished in corpora lutea of inhibitor-treated ovaries. Thus, Wnt/β-catenin signaling appears to participate in the regulation of corpus luteum development and luteal cell function.

Ovarian function following targeted anti-angiogenic therapy with bevacizumab

Improvements in cancer therapy have enabled further insight into the long-term effects of treatment, including the highly prevalent gonadal failure. The focus of treatment has been shifted to the preservation of fertility, which may be achieved by preventing ovarian toxicity. To this end, new molecular-targeted agents, including monoclonal antibodies, have been developed and used in a standard procedure for managing different cancers. However, the prolonged antitumor activity of these drugs may cause the emergence of new toxic effects. The aim of the present review was to discuss the leading toxic effect of the anti-angiogenic agent bevacizumab on ovarian function in female patients of reproductive age, which may be observed and expected during in clinical practice. The majority of bevacizumab-induced side effects are expected to be transient and eliminated within the anticipated drug clearance time frame; however, fundamental investigations on these effects are required for generating more evidence-based practice guidelines.

Effects of excess metabolizable protein on ovarian function and circulating amino acids of beef cows: 2. Excessive supply in varying concentrations from corn gluten meal

In the dairy industry, excess dietary CP is consistently correlated with decreased conception rates. However, amount of excess CP effects on reproductive function in beef cattle is largely undefined. The objective of this experiment was to determine the effects of excess metabolizable protein (MP) supplementation from a moderately abundant rumen undegradable protein (RUP) source (corn gluten meal: 62% RUP) on ovarian function and circulating amino acid (AA) concentrations in beef cows consuming low quality forage. Non-pregnant, non-lactating beef cows (n=16) were allocated by age, BW and body condition score (BCS) to 1 of 2 isocaloric supplements designed to maintain BW for 60 days. Cows had ad libitum access to corn stalks and were individually offered a corn gluten meal-based supplement daily at 125% (MP125) or 150% (MP150) of National Research Council (NRC) MP requirements. After a 20-day supplement adaptation period, cows were synchronized for ovulation. After 10 days of synchronization, follicular growth was reset with gonadotropin releasing hormone. Daily thereafter, transrectal ultrasonography was performed to diagram ovarian follicular waves, and blood samples were collected for hormone, metabolite and AA analyses. After 7 days of observation of estrus, corpus luteum (CL) size was determined via ultrasound. Data were analyzed using the MIXED procedures of SAS. No differences (P⩾0.21) in BW and BCS existed throughout the study; however, plasma urea N at ovulation was greater (P=0.04) in MP150. Preovulatory ovarian follicle size at dominance, duration of dominance, size at spontaneous luteolysis, length of proestrus and wavelength were not different (P⩾0.11) between treatments. However, ovulatory follicles were larger (P=0.04) and average antral follicle count was greater (P=0.01) in MP150 than MP125. Estradiol concentration and ratio of estradiol to ovulatory follicle volume were not different due to treatment (P⩾0.25). While CL volume 7 days post-estrus was greater (P<0.01) in MP150 than MP125, circulating progesterone 7 days post-estrus and ratio of progesterone to CL volume were not different (P⩾0.21). Total AA were not different (P⩾0.76) at study initiation or completion; however, as a percent of total AA, branched-chain AA at ovulation were greater (P=0.02) in MP150. In conclusion, supplementation of CP at 150% of NRC MP requirements from a moderately undegradable protein source may enhance growth of the ovulatory follicle and subsequent CL compared with MP supplementation at 125% of NRC MP requirements.

The Paracrine Effect of Transplanted Human Amniotic Epithelial Cells on Ovarian Function Improvement in a Mouse Model of Chemotherapy-Induced Primary Ovarian Insufficiency

Human amnion epithelial cells (hAECs) transplantation via tail vein has been reported to rescue ovarian function in mice with chemotherapy-induced primary ovarian insufficiency (POI). To test whether intraperitoneally transplanted hAECs could induce therapeutic effect and to characterize the paracrine effect of transplanted hAECs, we utilized a chemotherapy induced mice model of POI and investigated the ability of hAECs and conditioned medium collected from cultured hAECs (hAECs-CM) to restore ovarian function. We found that transplantation of hAECs or hAECs-CM either 24 hours or 7 days after chemotherapy could increase follicle numbers and partly restore fertility. By PCR analysis of recipient mice ovaries, the presence of SRY gene was only detected in mice transplanted with male hAECs 24 hours following chemotherapy. Further, the gene expression level of VEGFR1 and VEGFR2 in the ovaries decreased, although VEGFA increased 2 weeks after chemotherapy. After treatment with hAECs or hAEC-CM, the expression of both VEGFR1 and VEGFR2 increased, consistent with the immunohistochemical analysis. In addition, both hAECs and hAECs-CM treatment enhanced angiogenesis in the ovaries. The results suggested that hAECs-CM, like hAECs, could partly restore ovarian function, and the therapeutic function of intraperitoneally transplanted hAECs was mainly induced by paracrine-mediated ovarian protection and angiogenesis.

Expression of angiogenic factors and luteinizing hormone receptors in the corpus luteum of mares induced to ovulate with deslorelin acetate

The effects of deslorelin acetate use in inducing ovulation need to be clarified to improve the results of equine embryo transfer. The mRNA abundance for angiogenic factors and LH receptor (LHR) in corpus luteum (CL) was studied in mares with natural (control group [CG]) and induced ovulation with deslorelin acetate (treatment group [TG]; follicles: ≥ 35 mm). Transrectal ultrasonography was used to verify the ovulation day, and on Days 4, 8, and 12 after ovulation (Day 0), CL samples were obtained through ultrasound-guided biopsy. The messenger RNA expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and LHR genes were analyzed by real-time polymerase chain reaction. A positive correlation was observed between VEGF and LHR (P < 0.00001, r = 0.78), and it was possible to detect higher LHR expression in the TG than in the CG on Day 4 (P < 0.05). Moreover, this expression was higher on Days 4 and 8 than on Day 12 in the TG. Basic fibroblast growth factor was also expressed in luteal tissue on all days for both groups; however, these differences were not significant. In conclusion, deslorelin acetate was effective for the induction of ovulation in mares, resulting in higher expression of LHR, especially on the fourth day after ovulation. In addition, VEGF expression was influenced by induced ovulation, with a lower level on Day 12, which is expected in nonpregnant mares.

Inhibition of platelet-derived growth factor (PDGF) receptor affects follicular development and ovarian proliferation, apoptosis and angiogenesis in prepubertal eCG-treated rats

The platelet-derived growth factor (PDGF) system is crucial for blood vessel stability. In the present study, we evaluated whether PDGFs play a critical intraovarian survival role in gonadotropin-dependent folliculogenesis. We examined the effect of intrabursal administration of a selective platelet-derived growth factor receptor (PDGFR) inhibitor (AG1295) on follicular development, proliferation, apoptosis and blood vessel formation and stability in ovaries from rats treated with equine chorionic gonadotropin (eCG). The percentages of preantral follicles (PAFs) and early antral follicles (EAFs) were lower in AG1295-treated ovaries than in control ovaries (p < 0.01-0.05). The percentage of atretic follicles (AtrFs) increased in AG1295-treated ovaries compared to control (p < 0.05). The ovarian weight and estradiol concentrations were lower in AG1295-treated ovaries than in the control group (p < 0.01 and p < 0.05, respectively), whereas progesterone concentrations did not change. AG1295 decreased the proliferation index in EAFs (p < 0.05) and increased the percentage of nuclei positive for cleaved caspase-3 and apoptotic DNA fragmentation (p < 0.01-0.05). AG1295 increased the expression of Bax (p < 0.05) without changes in the expression of Bcl-2 protein. AG1295-treated ovaries increased the cleavage of caspase-8 (p < 0.05) and decreased AKT and BAD phosphorylation compared with control ovaries (p < 0.05). AG1295 caused a decrease not only in the endothelial cell area but also in the area of pericytes and vascular smooth muscle cells (VSMCs) in the ovary (p < 0.05). Our findings suggest that the local inhibition of PDGFs causes an increase in ovarian apoptosis through an imbalance in the ratio of antiapoptotic to proapoptotic proteins, thus leading a larger number of follicles to atresia. PDGFs could exert their mechanism of action through an autocrine/paracrine effect on granulosa and theca cells mediated by PDGFRs. In conclusion, these data clearly indicate that the PDGF system is necessary for follicular development induced by gonadotropins.