FSHR-mTOR-HIF1 signaling alleviates mouse follicles from AMPK-induced atresia

The majority of activated ovarian follicles undergo atresia during reproductive life in mammals, and only a small number of follicles are ovulated. Though hormone treatment has been widely used to promote folliculogenesis, the molecular mechanism behind follicle selection and atresia remains under debate due to inconsistency among investigation models. Using a high-throughput molecular pathology strategy, we depicted a transcriptional atlas of mouse follicular granulosa cells (GCs) under physiological condition and obtained molecular signatures in healthy and atresia GCs during development. Functional results revealed hypoxia-inducible factor 1 (HIF1) as a major effector downstream of follicle-stimulating hormone (FSH), and HIF1 activation is essential for follicle growth. Energy shortage leads to prevalent AMP-activated protein kinase (AMPK) activation and drives follicular atresia. FSHR-mTOR-HIF1 signaling helps follicles escape from the atresia fate, while energy stress persists. Our work provides a comprehensive understanding of the molecular network behind follicle selection and atresia under physiological condition.

Encapsulated Allografts Preclude Host Sensitization and Promote Ovarian Endocrine Function in Ovariectomized Young Rhesus Monkeys and Sensitized Mice

Transplantation of allogeneic donor ovarian tissue holds great potential for female cancer survivors who often experience premature ovarian insufficiency. To avoid complications associated with immune suppression and to protect transplanted ovarian allografts from immune-mediated injury, we have developed an immunoisolating hydrogel-based capsule that supports the function of ovarian allografts without triggering an immune response. Encapsulated ovarian allografts implanted in naïve ovariectomized BALB/c mice responded to the circulating gonadotropins and maintained function for 4 months, as evident by regular estrous cycles and the presence of antral follicles in the retrieved grafts. In contrast to non-encapsulated controls, repeated implantations of encapsulated mouse ovarian allografts did not sensitize naïve BALB/c mice, which was confirmed with undetectable levels of alloantibodies. Further, encapsulated allografts implanted in hosts previously sensitized by the implantation of non-encapsulated allografts restored estrous cycles similarly to our results in naïve recipients. Next, we tested the translational potential and efficiency of the immune-isolating capsule in a rhesus monkey model by implanting encapsulated ovarian auto- and allografts in young ovariectomized animals. The encapsulated ovarian grafts survived and restored basal levels of urinary estrone conjugate and pregnanediol 3-glucuronide during the 4- and 5-month observation periods. We demonstrate, for the first time, that encapsulated ovarian allografts functioned for months in young rhesus monkeys and sensitized mice, while the immunoisolating capsule prevented sensitization and protected the allograft from rejection.

cAMP signaling in ovarian physiology in teleosts: A review

Ovarian function in teleosts, like in other vertebrates, is regulated by two distinct gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Gonadotropin effects are mediated by membrane-bound G protein-coupled receptors localized on the surface of follicle cells. Gonadotropin receptor activation results in increased intracellular cAMP, the most important second cellular signaling molecule. FSH stimulation induces the production of 17β-estradiol in the cells of growing follicles to promote vitellogenesis in oocytes. In contrast, in response to LH, fully grown post-vitellogenic follicles gain the ability to synthesize maturation-inducing steroids, which induce meiotic resumption and ovulation. All these events were induced downstream of cAMP. In this review, we summarize studies addressing the role of the cAMP pathway in gonadotropin-induced processes in teleost ovarian follicles. Furthermore, we discuss future problems concerning cAMP signaling in relation to teleost ovarian function and the differences and similarities in the gonadotropin-induced cAMP signaling pathways between mammals and teleosts.

Checkpoint inhibitor immunotherapy diminishes oocyte number and quality in mice

Loss of fertility is a major concern for female reproductive-age cancer survivors, since a common side-effect of conventional cytotoxic cancer therapies is permanent damage to the ovary. While immunotherapies are increasingly becoming a standard of care for many cancers-including in the curative setting-their impacts on ovarian function and fertility are unknown. We evaluated the effect of immune checkpoint inhibitors blocking programmed cell death protein ligand 1 and cytotoxic T lymphocyte-associated antigen 4 on the ovary using tumor-bearing and tumor-free mouse models. We find that immune checkpoint inhibition increases immune cell infiltration and tumor necrosis factor-α expression within the ovary, diminishes the ovarian follicular reserve and impairs the ability of oocytes to mature and ovulate. These data demonstrate that immune checkpoint inhibitors have the potential to impair both immediate and future fertility, and studies in women should be prioritized. Additionally, fertility preservation should be strongly considered for women receiving these immunotherapies, and preventative strategies should be investigated in future studies.

Regulation of antral follicular growth by an interplay between gonadotropins and their receptors

Knowledge of the growth and maturation of human antral follicles is based mainly on concepts and deductions from clinical observations and animal models. To date, new experimental approaches and in vitro data contributed to a deep comprehension of gonadotropin receptors' functioning and may provide new insights into the mechanisms regulating still unclear physiological events. Among these, the production of androgen in the absence of proper LH levels, the programming of follicular atresia and dominance are some of the most intriguing. Starting from evolutionary issues at the basis of the gonadotropin receptor signal specificity, we draw a new hypothesis explaining the molecular mechanisms of the antral follicular growth, based on the modulation of endocrine signals by receptor-receptor interactions. The "heteromer hypothesis" explains how opposite death and life signals are delivered by gonadotropin receptors and other membrane partners, mediating steroidogenesis, apoptotic events, and the maturation of the dominant follicle.

Mouse Cre drivers: tools for studying disorders of the human female neuroendocrine-reproductive axis†

Benign disorders of the human female reproductive system, such primary ovarian insufficiency and polycystic ovary syndrome are associated with infertility and recurrent miscarriage, as well as increased risk of adverse health outcomes, including cardiovascular disease and type 2 diabetes. For many of these conditions, the contributing molecular and cellular processes are poorly understood. The overarching similarities between mice and humans have rendered mouse models irreplaceable in understanding normal physiology and elucidating pathological processes that underlie disorders of the female reproductive system. The utilization of Cre-LoxP recombination technology, which allows for spatial and temporal control of gene expression, has identified the role of numerous genes in development of the female reproductive system and in processes, such as ovulation and endometrial decidualization, that are required for the establishment and maintenance of pregnancy in mammals. In this comprehensive review, we provide a detailed overview of Cre drivers with activity in the neuroendocrine-reproductive axis that have been used to study disruptions in key intracellular signaling pathways. We first summarize normal development of the hypothalamus, pituitary, ovary, and uterus, highlighting similarities and differences between mice and humans. We then describe human conditions resulting from abnormal development and/or function of the organ. Finally, we describe loss-of-function models for each Cre driver that elegantly recapitulate some key features of the human condition and are associated with impaired fertility. The examples we provide illustrate use of each Cre driver as a tool for elucidating genetic and molecular underpinnings of reproductive dysfunction.

The Function of Cumulus Cells in Oocyte Growth and Maturation and in Subsequent Ovulation and Fertilization

Cumulus cells (CCs) originating from undifferentiated granulosa cells (GCs) differentiate in mural granulosa cells (MGCs) and CCs during antrum formation in the follicle by the distribution of location. CCs are supporting cells of the oocyte that protect the oocyte from the microenvironment, which helps oocyte growth and maturation in the follicles. Bi-directional communications between an oocyte and CCs are necessary for the oocyte for the acquisition of maturation and early embryonic developmental competence following fertilization. Follicle-stimulation hormone (FSH) and luteinizing hormone (LH) surges lead to the synthesis of an extracellular matrix in CCs, and CCs undergo expansion to assist meiotic resumption of the oocyte. The function of CCs is involved in the completion of oocyte meiotic maturation and ovulation, fertilization, and subsequent early embryo development. Therefore, understanding the function of CCs during follicular development may be helpful for predicting oocyte quality and subsequent embryonic development competence, as well as pregnancy outcomes in the field of reproductive medicine and assisted reproductive technology (ART) for infertility treatment.

Expression of CCL2/CCR2 signaling proteins in breast carcinoma cells is associated with invasive progression

Ductal carcinoma in situ (DCIS) is the most common type of pre-invasive breast cancer diagnosed in women. Because the majority of DCIS cases are unlikely to progress to invasive breast cancer, many women are over-treated for DCIS. By understanding the molecular basis of early stage breast cancer progression, we may identify better prognostic factors and design treatments tailored specifically to the predicted outcome of DCIS. Chemokines are small soluble molecules with complex roles in inflammation and cancer progression. Previously, we demonstrated that CCL2/CCR2 chemokine signaling in breast cancer cell lines regulated growth and invasion through p42/44MAPK and SMAD3 dependent mechanisms. Here, we sought to determine the clinical and functional relevance of CCL2/CCR2 signaling proteins to DCIS progression. Through immunostaining analysis of DCIS and IDC tissues, we show that expression of CCL2, CCR2, phospho-SMAD3 and phospho-p42/44MAPK correlate with IDC. Using PDX models and an immortalized hDCIS.01 breast epithelial cell line, we show that breast epithelial cells with high CCR2 and high CCL2 levels form invasive breast lesions that express phospho-SMAD3 and phospho-p42/44MAPK. These studies demonstrate that increased CCL2/CCR2 signaling in breast tissues is associated with DCIS progression, and could be a signature to predict the likelihood of DCIS progression to IDC.

Histomorphology and gene expression profiles during early ovarian folliculogenesis in duck and goose

In contrast to the later stages of follicle development, little is known about the characteristics and mechanisms associated with early folliculogenesis in avian species. The objectives of the present study were to examine and compare the histomorphological and molecular changes of primordial, primary, and secondary follicles from duck and goose ovaries during the first 6 post-hatching week. Morphological analysis showed that the length and width of both duck and goose ovaries increased steadily during weeks 1 to 5 but increased acutely at week 6, whereas a greater increment was observed in the ovarian length of ducks than that of geese during weeks 4 to 5. Furthermore, smaller diameters of the 3 categories of follicles were observed in ducks than those in geese at the first appearance, but they reached a similar size at week 6. More importantly, secondary follicles were found in the ovaries of ducks 1 wk earlier than in those of geese. These results indicated a more rapid growth rate for ovarian follicles in ducks than in geese during early post-hatching development. At the molecular level, it was found that the mRNAs encoding follicle stimulating hormone receptor (FSHR), anti-Müllerian hormone (AMH), B-cell leukemia/lymphoma 2, and cysteine-dependent aspartate specific protease 3 (CASPASE3) were ubiquitously expressed in all ovarian follicles of ducks and geese with different expression profiles in each follicular category during the first 6 post-hatching week. Notably, transcript levels of FSHR, AMH, and CASPASE3 changed differently between ducks and geese during weeks 5 to 6, which was postulated to be one of the mechanisms inducing more rapid growth of ovarian follicles in ducks rather than in geese. In conclusion, our results revealed, for the first time, differences in early folliculogenesis, including the rate of growth of each follicular category and the timing of transition of primary to secondary follicles, between ducks and geese, and these differences could result from different expression profiles of FSHR, AMH, and CASPASE3 during early post-hatching development.

Nuclear receptors: Key regulators of somatic cell functions in the ovulatory process

The development of the ovarian follicle to its culmination by ovulation is an essential element of fertility. The final stages of ovarian follicular growth are characterized by granulosa cell proliferation and differentiation, and steroid synthesis under the influence of follicle-stimulating hormone (FSH). The result is a population of granulosa cells poised to respond to the ovulatory surge of luteinizing hormone (LH). Members of the nuclear receptor superfamily of transcription factors play indispensable roles in the regulation of these events. The key regulators of the final stages of follicular growth that precede ovulation from this family include the estrogen receptor beta (ESR2) and the androgen receptor (AR), with additional roles for others, including steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1). Following the LH surge, the mural and cumulus granulosa cells undergo rapid changes that result in expansion of the cumulus layer, and a shift in ovarian steroid hormone biosynthesis from estradiol to progesterone production. The nuclear receptor best associated with these events is LRH-1. Inadequate cumulus expansion is also observed in the absence of AR and ESR2, but not the progesterone receptor (PGR). The terminal stages of ovulation are regulated by PGR, which increases the abundance of the proteases that are directly responsible for rupture. It further regulates the prostaglandins and cytokines associated with the inflammatory-like characteristics of ovulation. LRH-1 regulates PGR, and is also a key regulator of steroidogenesis, cellular proliferation, and cellular migration, and cytoskeletal remodeling. In summary, nuclear receptors are among the panoply of transcriptional regulators with roles in ovulation, and several are necessary for normal ovarian function.

miR-458b-5p regulates ovarian granulosa cells proliferation through Wnt/β-catenin signaling pathway by targeting catenin beta-1

OBJECTIVE

Ovarian follicular development, which dependent on the proliferation and differentiation of granulosa cells (GCs), is a complex biological process in which miRNA plays an important role. Our previous study showed that miR-458b-5p is associated with ovarian follicular development in chicken. The detailed function and molecular mechanism of miR-458b-5p in GCs is unclear.

METHODS

The luciferase reporter assay was used to verify the targeting relationship between miR-458b-5p and catenin beta-1 (CTNNB1), which is an important transcriptional regulatory factor of the Wnt/β-catenin pathway. The cell counting kit-8 (CCK-8) assay, flow cytometry with propidium iodide (PI) and annexin V-fluorescein isothiocyanate (FITC) labeling were applied to explore the effect of miR-458b-5p on proliferation, cell cycle and apoptosis of chicken GCs. Quantitative real-time polymerase chain reaction and Western blot were used to detect the mRNA and protein expression levels.

RESULTS

We demonstrated that the expression of miR-458b-5p and CTNNB1 showed the opposite relationship in GCs and theca cells of hierarchical follicles. The luciferase reporter assay confirmed that CTNNB1 is the direct target of miR-458b-5p. Using CCK-8 assay and flow cytometry with PI and Annexin V-FITC labeling, we observed that transfection with the miR-458b-5p mimics significantly reduced proliferation and has no effects on apoptosis of chicken GCs. In addition, miR-458b-5p decreased the mRNA and protein expression of CD44 molecule and matrix metallopeptidase 7, which are the downstream effectors of CTNNB1 in Wnt/β-Catenin pathway and play functional roles in cell proliferation.

CONCLUSION

Taken together, the data indicate that miR-458b-5p regulates ovarian GCs proliferation through Wnt/β-catenin signaling pathway by targeting CTNNB1, suggesting that miR-458b-5p and its target gene CTNNB1 may potentially play a role in chicken ovarian follicular development.

Temporal patterns of gene regulation and upstream regulators contributing to major developmental transitions during Rhesus macaque preimplantation development

The preimplantation period of life in mammals encompasses a tremendous amount of restructuring and remodeling of the embryonic genome and reprogramming of gene expression. These vast changes support metabolic activation and cellular processes that drive early cleavage divisions and enable the creation of the earliest primitive cell lineages. A major question in mammalian embryology is how such vast, sweeping changes in gene expression are orchestrated, so that changes in gene expression are exactly appropriate to meet the developmental needs of the embryo over time. Using the rhesus macaque as an experimentally tractable model species closely related to the human, we combined high quality RNA-seq libraries, in-depth sequencing and advanced systems analysis to discover the underlying mechanisms that drive major changes in gene regulation during preimplantation development. We identified the major changes in mRNA population and the biological pathways and processes impacted by those changes. Most importantly, we identified 24 key upstream regulators that are themselves modulated during development and that are associated with the regulation of over 1000 downstream genes. Through their roles in extensive gene networks, these 24 upstream regulators are situated to either drive major changes in target gene expression or modify the cellular environment in which other genes function, thereby directing major developmental transitions in the preimplantation embryo. The data presented here highlight some of the specific molecular features that likely drive preimplantation development in a nonhuman primate species and provides an extensive database for novel hypothesis-driven studies.

Expression of SUMO associated proteins in the mouse endometrium is regulated by ovarian hormones throughout the estrous cycle

The modification of proteins by small ubiquitin-like modifier (SUMO), known as SUMOylation, regulates biological function by changing protein transcription and translation. During the estrous cycle the endometrium undergoes continual change to processes including cell proliferation, secretion and exfoliation and these changes are regulated by the levels of ovarian hormones. Increasing the expression of SUMO family members has previously been shown to promote proliferation and invasion of endometrial cancer cells. However, limited research has been carried out into the expression and function of SUMO in the mammalian endometrium. In the present study, the level and localization of SUMO-associated proteins throughout the natural estrous cycle in the mouse uterus was determined using immunohistochemical staining and western blot analysis. The association between the spatiotemporal expression of these SUMO modified proteins and SENPs in endometrium and the concentration of ovarian hormones during estrous cycle was revealed. The present study clarified the role of SUMOylation in maintenance of normal estrous cycling and may have important significance in the study of hormone-dependent endometrial diseases.

Naturally Occurring and Experimentally Induced Rhesus Macaque Models for Polycystic Ovary Syndrome: Translational Gateways to Clinical Application

Indian rhesus macaque nonhuman primate models for polycystic ovary syndrome (PCOS) implicate both female hyperandrogenism and developmental molecular origins as core components of PCOS etiopathogenesis. Establishing and exploiting macaque models for translational impact into the clinic, however, has required multi-year, integrated basic-clinical science collaborations. Paradigm shifting insight has accrued from such concerted investment, leading to novel mechanistic understanding of PCOS, including hyperandrogenic fetal and peripubertal origins, epigenetic programming, altered neural function, defective oocytes and embryos, adipogenic constraint enhancing progression to insulin resistance, pancreatic decompensation and type 2 diabetes, together with placental compromise, all contributing to transgenerational transmission of traits likely to manifest in adult PCOS phenotypes. Our recent demonstration of PCOS-related traits in naturally hyperandrogenic (High T) female macaques additionally creates opportunities to employ whole genome sequencing to enable exploration of gene variants within human PCOS candidate genes contributing to PCOS-related traits in macaque models. This review will therefore consider Indian macaque model contributions to various aspects of PCOS-related pathophysiology, as well as the benefits of using macaque models with compellingly close homologies to the human genome, phenotype, development and aging.

Inflammation and angiogenesis in the corpus luteum

Angiogenesis is a very important process that helps establish and maintain the normal structure and function of the corpus luteum (CL). Early luteal development can be considered a kind of physiological injury with an inflammatory response; therefore, the inflammatory response may play an important role in the luteal angiogenesis. The inflammatory response is companied by activated leukocytes and their mediators. For luteal tissue, numerous activated leukocytes such as macrophages, neutrophils and eosinophils are present in the early luteal phase and are widely involved in neovascularization. The objective of this review is to describe the role of the inflammatory factors in the angiogenesis and to discuss their mechanism. Knowledge of action and mechanism of these inflammatory factors on angiogenic activity will be beneficial for the understanding of luteal function.

Transcriptome analysis of rhesus monkey failed-to-mature oocytes: deficiencies in transcriptional regulation and cytoplasmic maturation of the oocyte mRNA population

STUDY QUESTION

Which different pathways and functions are altered in rhesus monkey oocytes that fail to mature after an ovulatory stimulus?

SUMMARY ANSWER

Failed to mature (FTM) oocytes complete a large portion of the transition in transcriptome composition associated with normal maturation, but also manifest numerous differences that indicate incomplete transcriptional repression and cytoplasmic maturation affecting multiple processes.

WHAT IS KNOWN ALREADY

Oocyte maturation defects contribute to unexplained female infertility. Failure of some oocytes to undergo germinal vesicle breakdown or progress to second meiotic metaphase in response to an ovulatory stimulus can limit the number of high quality oocytes available for ART.

STUDY DESIGN, SIZE, DURATION

The transcriptome of rhesus monkey oocytes that failed to mature (FTM; n = 11, 5 donors) in response to an ovulatory stimulus in vivo was compared to those of normal germinal vesicle stage (GV, n = 7, 2 donors) and metaphase II stage (MII, n = 7, 5 donors) oocytes by RNA-sequencing (RNAseq).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Female rhesus monkeys of normal breeding age (6-12 years old) and with regular menstrual cycles were used. Animals underwent a controlled ovarian stimulation protocol for the collection of oocytes by ultrasound-guided needle aspiration of follicles.

MAIN RESULTS AND THE ROLE OF CHANCE

We obtained a high quality RNAseq dataset consisting of n = 7, n = 7, and n = 11 libraries for normal GV, normal MII and FTM oocytes, respectively. Total reads acquired were an average of 34 million for each GV sample, 41 million for each FTM sample and 59 million for each MII oocyte sample. Approximately 44% of the total reads were exonic reads that successfully aligned to the rhesus monkey genome as unique non-rRNA gene transcript sequences, providing high depth of coverage. Approximately 44% of the mRNAs that undergo changes in abundance during normal maturation display partial modulations to intermediate abundances, and 9.2% fail to diverge significantly from GV stage oocytes. Additionally, a small group of mRNAs are grossly mis-regulated in the FTM oocyte. Differential expression was seen for mRNAs associated with mitochondrial functions, fatty acid beta oxidation, lipid accumulation, meiosis, zona pellucida formation, Hippo pathway signaling, and maternal mRNA regulation. A deficiency DNA methyltransferase one mRNA expression indicates a potential defect in transcriptional silencing.

LARGE SCALE DATA

All RNAseq data are published in the Gene Expression Omnibus Database (GSE112536).

LIMITATIONS, REASONS FOR CAUTION

These results do not establish cause of maturation failure but reveal novel correlates of incompetence to mature. Transcriptome studies likely do not capture all post-transcriptional or post-translational events that inhibit maturation, but do reveal mRNA expression changes that lie downstream of such events or that are related to effects on upstream regulators. The use of an animal model allows the study of oocyte maturation failure independent of covariates and confounders, such as pre-existing conditions of the female, which is a significant concern in human studies. Depending on the legislation, it may not be possible to collect and study oocytes from healthy women; and using surplus oocytes from patients undergoing ART may introduce confounders that vary from case to case. FTM oocytes were at various stages of meiotic progression, so correlates of specific times of arrest are not revealed. All the FTM oocytes failed to respond appropriately to an ovulatory stimulus in vivo. Therefore, this analysis informs us about common transcriptome features associated with meiotic incompetence.

WIDER IMPLICATIONS OF THE FINDINGS

These results reveal that some diagnostic markers of oocyte quality may not reflect developmental competence because even meiotically incompetent oocytes display many normal gene expression features. The results also reveal potential mechanisms by which maternal and environmental factors may impact transcriptional repression and cytoplasmic maturation, and prevent oocyte maturation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from the National Institutes of Health Office of Research Infrastructure Programs Division of Comparative Medicine Grants R24 [OD012221 to K.E.L., OD011107/RR00169 (California National Primate Research Center), and OD010967/RR025880 to C.A.V.]; the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health under the award number T32HD087166; MSU AgBioResearch, Michigan State University. Authors have nothing to disclose.

Three populations of adult Leydig cells in mouse testes revealed by a novel mouse HSD3B1-specific rat monoclonal antibody

Leydig cells play a pivotal function in the synthesis of a male sex steroid, testosterone. The ability of the steroid production is dependent on the expression of the steroidogenic genes, such as HSD3B (3β-hydroxysteroid dehydrogenase/Δ5- Δ4 isomerase). It has been established that two different types of Leydig cells, fetal Leydig cells (FLCs) and adult Leydig cells (ALCs), are developed in mammalian testes. FLCs and ALCs are characterized by different sets of marker gene expression. In the case of mouse Leydig cells, Hsd3b1 (Hsd3b type 1) is expressed both in FLCs and ALCs whereas Hsd3b6 (Hsd3b type 6) is expressed in ALCs but not in FLCs. However, because the antibodies established so far for HSD3B were unable to distinguish between the HSD3B1 and HSD3B6 isoforms, it remained unclear whether both of them are expressed in every ALC. Therefore, in the present study, we generated a rat monoclonal antibody specific for mouse HSD3B1. Intriguingly, this monoclonal antibody together with an antibody specific for HSD3B6 identified three populations of ALCs based on the expression levels of these HSD3Bs.

Panax ginseng Extract Improves Follicular Development after Mouse Preantral Follicle 3D Culture

Objective

Panax ginseng is a popular traditional herb that has been used in complementary and alternative medicine in eastern Asia, and it possesses pharmacologically active compounds like ginsenosides (GSs). This study aimed to investigate the impact of Panax ginseng extract (PGE) at different concentrations on in vitro follicular function and development in a three-dimensional (3D) culture system fabricated using sodium alginate after 12 days of culture.

Materials and Methods

In this experimental study, preantral follicles (n=661) were mechanically isolated from the ovaries of 14-day-old female NMRI mice using 29-gauge insulin syringes. Follicles were individually capsulated within sodium alginate, and divided into four groups including control and experimental groups 1, 2, and 3. Then, they were cultured for 12 days in the medium supplemented with different concentrations of PGE (0, 50, 100, and 500 µg/ mL, for control groups and groups 1, 2 and 3, respectively). At the end of the culture period, the mean diameter and maturation of follicles, follicular steroid production, mRNA expression level of proliferating cell nuclear antigen (PCNA) and follicle stimulating hormone receptor (FSH-R), and reactive oxygen species (ROS) levels in collected metaphase-II (MII) oocytes were determined.

Results

The mean diameter of follicles in group 2 was significantly increased as compared to other groups (P<0.001). The percentages of the survival and maturation rate and levels of secreted hormones were higher in group 2 than the other groups (P<0.05). Follicles cultured in the presence of PGE 100 µg/mL had higher levels of proliferation cell nuclear antigen (PCNA) and follicle stimulating hormone receptor (FSH-R) mRNA expression in comparison to other groups (P<0.05). Moreover, oocytes collected from groups 2 and 3 had lower levels of ROS as compared to other groups (P<0.05).

Conclusion

Our results suggest that PGE at the concentration of 100 µg/mL induces higher follicular function and development in the 3D culture system.

Spatio-temporal expression profile of matrix metalloproteinase (Mmp) modulators Reck and Sparc during the rat ovarian dynamics

BACKGROUND

Matrix metalloproteinases (Mmps) and their tissue inhibitors (Timps) are widely recognized as crucial factors for extracellular matrix remodeling in the ovary and are involved in follicular growth, ovulation, luteinization, and luteolysis during the estrous cycle. Recently, several genes have been associated to the modulation of Mmps activity, including Basigin (Bsg), which induces the expression of Mmps in rat ovaries; Sparc, a TGF-β modulator that is related to increased expression of Mmps in cancer; and Reck, which is associated with Mmps inhibition. However, the expression pattern of Mmp modulators in ovary dynamics is still largely uncharacterized.

METHODS

To characterize the expression pattern of Mmps network members in ovary dynamics, we analyzed the spatio-temporal expression pattern of Reck and Sparc, as well as of Mmp2, Mmp9 and Mmp14 proteins, by immunohistochemistry (IHC), in pre-pubertal rat ovaries obtained from an artificial cycle induced by eCG/hCG, in the different phases of the hormone-induced estrous cycle. We also determined the gene expression profiles of Mmps (2, 9, 13 14), Timps (1, 2, 3), Sparc, Bsg, and Reck to complement this panel.

RESULTS

IHC analysis revealed that Mmp protein expression peaks at the early stages of folliculogenesis and ovulation, decreases during ovulation-luteogenesis transition and luteogenesis, increasing again during corpus luteum maintenance and luteolysis. The protein expression patterns of these metalloproteinases and Sparc were inverse relative to the pattern displayed by Reck. We observed that the gene expression peaks of Mmps inhibitors Reck and Timp2 were closely paraleled by Mmp2 and Mmp9 suppression. The opposite was also true: increased Mmp2 and Mmp9 expression was concomitant to reduced Reck and Timp2 levels.

CONCLUSION

Therefore, our results generate a spatio-temporal expression profile panel of Mmps and their regulators, suggesting that Reck and Sparc seem to play a role during ovarian dynamics: Reck as a possible inhibitor and Sparc as an inducer of Mmps.

Effects of Matricaria chamomilla Extract on Growth and Maturation of Isolated Mouse Ovarian Follicles in a Three-dimensional Culture System

BACKGROUND

The aim of this study was to design and assess the effects of hydroalcoholic extract of Matricaria chamomilla (MC) on preantral follicle culture of mouse ovaries in a three-dimensional culture system.

METHODS

Isolated preantral follicles were randomly divided into three main groups: the control group containing 10% fetal bovine serum without MC extract (G1), the first experimental group supplemented with 25 μg/ml hydroalcoholic extract of chamomile (G2), and the second experimental group supplemented with 50 μg/ml hydroalcoholic extract of chamomile (G3).

RESULTS

After 12 days of culture, the survival rate (P < 0.05), antrum formation (P < 0.01), metaphase two oocytes (P < 0.01), and the expression of PCNA (P < 0.05) and FSHR (P < 0.05) genes significantly decreased in G3 as compared with G1. On the other hand, at the last day of culture (day 12), the mean diameter of follicles cultured in the medium which was supplemented with 50 μg/ml hydroalcoholic extract of chamomile significantly decreased as compared with the G1 (P < 0.05). In addition, the levels of progesterone and dehydroepiandrosterone hormones significantly increased in the medium of G3 relative to G1 (P < 0.01), while in the medium of G1, the level of 17β-estradiol was significantly higher than that of other groups (P < 0.01). Reactive oxygen species levels of metaphase II oocytes were significantly decreased in G2 as compared with G1 (P < 0.01).

CONCLUSION

Adding chamomile extract to culture media appeared to decrease follicular function and development.

Histological and immunohistochemical investigations of ovarian interstitial glands during non-breeding season in camels (Camelus dromedarius)

The aim of this was to investigate the histology and immunohistochemistry of interstitial glands during non-breeding season in camel ovaries. A total of 21 mature, non-pregnant and apparently healthy camels aged between 8 and 12 years were slaughtered. The ovaries were removed within 15 min, cleaned from adipose tissue, weighted and examined grossly. The histological preparation was made, and then, the blocks were cut at 3-5 microns thickness and stained by H&E for histological examinations. Moreover, some sections were stained with Sudan Black for lipid detection. Immunohistochemical analysis of paraffin-embedded ovarian tissues was performed to detect the localization of S-100, vimentin, progesterone receptors (PR) and oestrogen receptors (ER). Immunoreactive signals were detected using UltraVision Detection System. The results revealed that the interstitial glands were located in the cortical region and they were arranged in various arrangements either single, in couple or in groups rich in lipid droplet. All interstitial gland arrangements were enclosed by connective tissue capsules containing fibroblasts and collagenous fibres separated them from the surrounding ovarian structures. Both interstitial glands and their surrounding CT were penetrated by several blood vessels. There was a strong immunoreactive signal for S-100 in the nuclei of interstitial cells, and no signals were detected either in cells of the interstitial glands or their connective tissue with PR. We could conclude that the interstitial gland is distinct in ovary of camel and further studies are needed to elucidate its rule in steroid synthesis.

A novel fibrin-based artificial ovary prototype resembling human ovarian tissue in terms of architecture and rigidity

PURPOSE

The aim of this study is to optimize fibrin matrix composition in order to mimic human ovarian tissue architecture for human ovarian follicle encapsulation and grafting.

METHODS

Ultrastructure of fresh human ovarian cortex in age-related women (n = 3) and different fibrin formulations (F12.5/T1, F30/T50, F50/T50, F75/T75), rheology of fibrin matrices and histology of isolated and encapsulated human ovarian follicles in these matrices.

RESULTS

Fresh human ovarian cortex showed a highly fibrous and structurally inhomogeneous architecture in three age-related patients, but the mean ± SD of fiber thickness (61.3 to 72.4 nm) was comparable between patients. When the fiber thickness of four different fibrin formulations was compared with human ovarian cortex, F50/T50 and F75/T75 showed similar fiber diameters to native tissue, while F12.5/T1 was significantly different (p value < 0.01). In addition, increased concentrations of fibrin exhibited enhanced storage modulus with F50/T50, resembling physiological ovarian rigidity. Excluding F12.5/T1 from further analysis, only three remaining fibrin matrices (F30/T50, F50/T50, F75/T75) were histologically investigated. For this, frozen-thawed fragments of human ovarian tissue collected from 22 patients were used to isolate ovarian follicles and encapsulate them in the three fibrin formulations. All three yielded similar follicle recovery and loss rates soon after encapsulation. Therefore, based on fiber thickness, porosity, and rigidity, we selected F50/T50 as the fibrin formulation that best mimics native tissue.

CONCLUSIONS

Of all the different fibrin matrix concentrations tested, F50/T50 emerged as the combination of choice in terms of ultrastructure and rigidity, most closely resembling human ovarian cortex.

Nonhuman Primates: A Vital Model for Basic and Applied Research on Female Reproduction, Prenatal Development, and Women's Health

The comparative biology of reproduction and development in mammalian species is remarkable. Hence, because of similarities in environmental and neuroendocrine control of the reproductive axis, the cyclic function of the ovary and reproductive tract, establishment and control of the maternal-fetal-placental unit during pregnancy, and reproductive aging from puberty through menopause, nonhuman primates (NHPs) are valuable models for research related to women's reproductive health and its disorders. This chapter provides examples of research over the past 10+ years using Old World monkeys (notably macaque species), baboons, and to a lesser extent New World monkeys (especially marmosets) that contributed to our understanding of the etiology and therapies or prevention of: (1) ovarian disorders, e.g., polycystic ovary syndrome, mitochondrial DNA-based diseases from the oocyte; (2) uterine disorders, for example, endometriosis and uterine transplantation; and (3) pregnancy disorders, for example, preterm labor and delivery, environmental factors. Also, emerging opportunities such as viral (e.g., Zika) induced fetal defects and germline genomic editing to generate valuable primate models of human diseases (e.g., Huntington and muscular dystrophy) are addressed. Although the high costs, specialized resources, and ethical debate challenge the use of primates in biomedical research, their inclusion in fertility and infertility research is vital for continued improvements in women's reproductive health.

The Sodium/Iodide Symporter (NIS): Molecular Physiology and Preclinical and Clinical Applications

Active iodide (I^-) transport in both the thyroid and some extrathyroidal tissues is mediated by the Na⁺/I^- symporter (NIS). In the thyroid, NIS-mediated I^- uptake plays a pivotal role in thyroid hormone (TH) biosynthesis. THs are key during embryonic and postembryonic development and critical for cell metabolism at all stages of life. The molecular characterization of NIS in 1996 and the use of radioactive I^- isotopes have led to significant advances in the diagnosis and treatment of thyroid cancer and provide the molecular basis for studies aimed at extending the use of radioiodide treatment in extrathyroidal malignancies. This review focuses on the most recent findings on I^- homeostasis and I^- transport deficiency-causing NIS mutations, as well as current knowledge of the structure/function properties of NIS and NIS regulatory mechanisms. We also discuss employing NIS as a reporter gene using viral vectors and stem cells in imaging, diagnostic, and therapeutic procedures.

Granulosa cell endothelin-2 expression is fundamental for ovulatory follicle rupture

Ovulation is dependent upon numerous factors mediating follicular growth, vascularization, and ultimately oocyte release via follicle rupture. Endothelin-2 (EDN2) is a potent vasoconstrictor that is transiently produced prior to follicle rupture by granulosa cells of periovulatory follicles and induces ovarian contraction. To determine the role of Edn2 expression, surgical transplant and novel conditional knockout mice were super-ovulated and analyzed. Conditional knockout mice utilized a new iCre driven by the Esr2 promoter to selectively remove Edn2. Follicle rupture and fertility were significantly impaired in the absence of ovarian Edn2 expression. When ovaries of Edn2KO mice were transplanted in wild type recipients, significantly more corpora lutea containing un-ovulated oocytes were present after hormonal stimulation (1.0 vs. 5.4, p = 0.010). Following selective ablation of Edn2 in granulosa cells, Esr2-Edn2KO dams had reduced oocytes ovulated (3.8 vs. 16.4 oocytes/ovary) and smaller litters (4.29 ± l.02 vs. 8.50 pups/dam). However, the number of pregnancies per pairing was not different and the reproductive axis remained intact. Esr2-Edn2KO ovaries had a higher percentage of antral follicles and fewer corpora lutea; follicles progressed to the antral stage but many were unable to rupture. Conditional loss of endothelin receptor A in granulosa cells also decreased ovulation but did not affect fecundity. These data demonstrate that EDN2-induced intraovarian contraction is a critical trigger of normal ovulation and subsequent fecundity.

Knockdown of Progesterone Receptor (PGR) in Macaque Granulosa Cells Disrupts Ovulation and Progesterone Production

Adenoviral vectors (vectors) expressing short-hairpin RNAs complementary to macaque nuclear progesterone (P) receptor PGR mRNA (shPGR) or a nontargeting scrambled control (shScram) were used to determine the role PGR plays in ovulation/luteinization in rhesus monkeys. Nonluteinized granulosa cells collected from monkeys (n = 4) undergoing controlled ovarian stimulation protocols were exposed to either shPGR, shScram, or no virus for 24 h; human chorionic gonadotropin (hCG) was then added to half of the wells to induce luteinization (luteinized granulosa cells [LGCs]; n = 4-6 wells/treatment/monkey). Cells/media were collected 48, 72, and 120 h postvector for evaluation of PGR mRNA and P levels. Addition of hCG increased (P < 0.05) PGR mRNA and medium P levels in controls. However, a time-dependent decline (P < 0.05) in PGR mRNA and P occurred in shPGR vector groups. Injection of shPGR, but not shScram, vector into the preovulatory follicle 20 h before hCG administration during controlled ovulation protocols prevented follicle rupture in five of six monkeys as determined by laparoscopic evaluation, with a trapped oocyte confirmed in three of four follicles of excised ovaries. Injection of shPGR also prevented the rise in serum P levels following the hCG bolus compared to shScram (P < 0.05). Nuclear PGR immunostaining was undetectable in granulosa cells from shPGR-injected follicles, compared to intense staining in shScram controls. Thus, the nuclear PGR appears to mediate P action in the dominant follicle promoting ovulation in primates. In vitro and in vivo effects of PGR knockdown in LGCs also support the hypothesis that P enhances its own synthesis in the primate corpus luteum by promoting luteinization.

Maternal High-Fat Diet-Induced Loss of Fetal Oocytes Is Associated with Compromised Follicle Growth in Adult Rat Offspring

Maternal obesity predisposes offspring to metabolic and reproductive dysfunction. We have shown previously that female rat offspring born to mothers fed a high-fat (HF) diet throughout pregnancy and lactation enter puberty early and display aberrant reproductive cyclicity. The mechanisms driving this reproductive phenotype are currently unknown thus we investigated whether changes in ovarian function were involved. Wistar rats were mated and randomized to: dams fed a control diet (CON) or dams fed a HF diet from conception until the end of lactation (HF). Ovaries were collected from fetuses at Embryonic Day (E) 20, and neonatal ovaries at Day 4 (P4), prepubertal ovaries at P27 and adult ovaries at P120. In a subset of offspring, the effects of a HF diet fed postweaning were evaluated. The present study shows that fetuses of mothers fed a HF diet had significantly fewer oocytes at E20, and in neonates, have reduced AMH signaling that may facilitate an increased number of assembled primordial follicles. Both prepubertally and in adulthood, ovaries show increased follicular atresia. As adults, offspring have reduced FSH responsiveness, low expression levels of estrogen receptor alpha (Eralpha), the oocyte-secreted factor, Gdf9, oocyte-specific RNA binding protein, Dazl, and high expression levels of the granulosa-cell derived factor, AMH, in antral follicles. Together, these data suggest that ovarian compromise in offspring born to HF-fed mothers may arise from changes already observable in the fetus and neonate and in the long term, associated with increased follicular atresia through adulthood.

Molecular characterization and quantification of the follicle-stimulating hormone receptor in turbot (Scophthalmus maximus)

Molecular cloning, characterization, and functional analysis of follicle-stimulating hormone receptor (FSHR) in female turbot (Scophthalmus maximus) were evaluated. Results showed that the full-length FSHR cDNA was 3824 bp long and contained a 2202 bp open reading frame that encoded a mature protein of 733 amino acids (aa) and a signal peptide of 18 aa. Multiple sequence analyses showed that turbot FSHR has high homology with the corresponding genes of other teleosts and significant homology with that of Hippoglossus hippoglossus. Turbot FSHR has the typical structural architecture of glycoprotein hormone receptors consisting of a large N-terminal extracellular domain, seven transmembrane domains and short C-terminal intracellular domain. FSHR mRNA was found to be abundant in the ovaries, but deficient in eyes, intestine, brain, muscle, gills, spleen, stomach, heart and kidney. Furthermore, FSHR mRNA was found to increase gradually from pre-vitellogenesis to migratory nucleus stages, with the highest values observed during the late vitellogenesis stage of the reproductive cycle. However, FSHR mRNA was found to decrease dramatically during the atresia stage. Meanwhile, functional analysis with HEK293T cells continual expressing FSHR demonstrated that FSHR was specifically stimulated by ovine FSH, but not ovine LH. These results indicate that turbot FSHR is mainly involved in the stimulation of vitellogenesis, regulation of oocyte maturation as well as promotion of ovarian development via specific ligand binding. These findings open doors to further investigation of physiological functions of FSHR, which will be valuable for fish reproduction and broodstock management.

Genistein exposure inhibits growth and alters steroidogenesis in adult mouse antral follicles

Genistein is a naturally occurring isoflavone phytoestrogen commonly found in plant products such as soybeans, lentils, and chickpeas. Genistein, like other phytoestrogens, has the potential to mimic, enhance, or impair the estradiol biosynthesis pathway, thereby potentially altering ovarian follicle growth. Previous studies have inconsistently indicated that genistein exposure may alter granulosa cell proliferation and hormone production, but no studies have examined the effects of genistein on intact antral follicles. Thus, this study was designed to test the hypothesis that genistein exposure inhibits follicle growth and steroidogenesis in intact antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice were cultured with vehicle (dimethyl sulfoxide; DMSO) or genistein (6.0 and 36μM) for 18-96h. Every 24h, follicle diameters were measured to assess growth. At the end of each culture period, the media were pooled to measure hormone levels, and the cultured follicles were collected to measure expression of cell cycle regulators and steroidogenic enzymes. The results indicate that genistein (36μM) inhibits growth of mouse antral follicles. Additionally, genistein (6.0 and 36μM) increases progesterone, testosterone, and dehydroepiandrosterone (DHEA) levels, but decreases estrone and estradiol levels. The results also indicate that genistein alters the expression of steroidogenic enzymes at 24, 72 and 96h, and the expression of cell cycle regulators at 18h. These data indicate that genistein exposure inhibits antral follicle growth by inhibiting the cell cycle, alters sex steroid hormone levels, and dysregulates steroidogenic enzymes in cultured mouse antral follicles.

Dynamics of Immune Cell Types Within the Macaque Corpus Luteum During the Menstrual Cycle: Role of Progesterone

The goal of the current study was to characterize the immune cell types within the primate corpus luteum (CL). Luteal tissue was collected from rhesus females at discrete intervals during the luteal phase of the natural menstrual cycle. Dispersed cells were incubated with fluorescently labeled antibodies specific for the immune cell surface proteins CD11b (neutrophils and monocytes/macrophages), CD14 (monocytes/macrophages), CD16 (natural killer [NK] cells), CD20 (B-lymphocytes), and CD3epsilon (T-lymphocytes) for analysis by flow cytometry. Numbers of CD11b-positive (CD11b(+)) and CD14(+) cells increased significantly 3 to 4 days after serum progesterone (P4) concentrations declined below 0.3 ng/ml. CD16(+) cells were the most abundant immune cell type in CL during the mid and mid-late luteal phases and were 3-fold increased 3 to 4 days after serum P4 decreased to baseline levels. CD3epsilon(+) cells tended to increase 3 to 4 days after P4 decline. To determine whether immune cells were upregulated by the loss of luteotropic (LH) support or through loss of LH-dependent steroid milieu, monkeys were assigned to 4 groups: control (no treatment), the GnRH antagonist Antide, Antide plus synthetic progestin (R5020), or Antide plus the estrogen receptor agonists diarylpropionitrile (DPN)/propyl-pyrazole-triol (PPT) during the mid-late luteal phase. Antide treatment increased the numbers of CD11b(+) and CD14(+) cells, whereas progestin, but not estrogen, replacement suppressed the numbers of CD11b(+), CD14(+), and CD16(+) cells. Neither Antide nor steroid replacement altered numbers of CD3epsilon(+) cells. These data suggest that increased numbers of innate immune cells in primate CL after P4 synthesis declines play a role in onset of structural regression of primate CL.

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

STUDY QUESTION

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

SUMMARY ANSWER

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

WHAT IS KNOWN ALREADY

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

STUDY DESIGN, SIZE, DURATION

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

PARTICIPANTS/MATERIALS, SETTING, METHODS

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

MAIN RESULTS AND THE ROLE OF CHANCE

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

LIMITATIONS, REASONS FOR CAUTION

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

WIDER IMPLICATIONS OF THE FINDINGS

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

STUDY FUNDING/COMPETING INTERESTS

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

Heterogeneity of ovarian theca and interstitial gland cells in mice

It has been established that two developmentally and functionally distinct cell types emerge within the mammalian testis and adrenal gland throughout life. Fetal and adult types of steroidogenic cells (i.e., testicular Leydig cells and adrenocortical cells) develop in the prenatal and postnatal period, respectively. Although the ovary synthesizes steroids postnatally, the presence of fetal-type steroidogenic cells has not been described. We had previously established transgenic mouse lines in which fetal Leydig cells were labeled with an EGFP reporter gene by the FLE (fetal Leydig enhancer) of the Ad4BP/SF-1 (Nr5a1) gene. In the present study, we examined the reporter gene expression in females and found that the reporter gene is turned on in postnatal ovaries. A comparison of the expressions of the EGFP and marker genes revealed that EGFP is expressed in not all but rather a proportion of steroidogenic theca and in interstitial gland cells in the ovary. This finding was further supported by experiments using BAC transgenic mice in which reporter gene expression recapitulated endogenous Ad4BP/SF-1 gene expression. In conclusion, our observations from this study strongly suggest that ovarian theca and interstitial gland cells in mice consist of at least two cell types.

Of mice and women: a comparative tissue biology perspective of breast stem cells and differentiation

Tissue based research requires a background in human and veterinary pathology, developmental biology, anatomy, as well as molecular and cellular biology. This type of comparative tissue biology (CTB) expertise is necessary to tackle some of the conceptual challenges in human breast stem cell research. It is our opinion that the scarcity of CTB expertise contributed to some erroneous interpretations in tissue based research, some of which are reviewed here in the context of breast stem cells. In this article we examine the dissimilarities between mouse and human mammary tissue and suggest how these may impact stem cell studies. In addition, we consider the differences between breast ducts vs. lobules and clarify how these affect the interpretation of results in stem cell research. Lastly, we introduce a new elaboration of normal epithelial cell types in human breast and discuss how this provides a clinically useful basis for breast cancer classification.

C/EBPβ Isoforms Expression in the Rat Brain during the Estrous Cycle

The CCAAT/enhancer-binding protein beta (C/EBPβ) is a transcription factor expressed in different areas of the brain that regulates the expression of several genes involved in cell differentiation and proliferation. This protein has three isoforms (LAP1, LAP2, and LIP) with different transcription activation potential. The role of female sex hormones in the expression pattern of C/EBPβ isoforms in the rat brain has not yet been described. In this study we demonstrate by western blot that the expression of the three C/EBPβ isoforms changes in different brain areas during the estrous cycle. In the cerebellum, LAP2 content diminished on diestrus and proestrus and LIP content diminished on proestrus and estrus days. In the prefrontal cortex, LIP content was higher on proestrus and estrus days. In the hippocampus, LAP isoforms presented a switch on diestrus day, since LAP1 content was the highest while that of LAP2 was the lowest. The LAP2 isoform was the most abundant one in all the three brain areas. The LAP/LIP ratio changed throughout the cycle and was tissue specific. These results suggest that C/EBPβ isoforms expression changes in a tissue-specific manner in the rat brain due to the changes in sex steroid hormone levels presented during the estrous cycle.

Matrix metalloproteinase 2 is required for ovulation and corpus luteum formation in Drosophila

Ovulation is critical for successful reproduction and correlates with ovarian cancer risk, yet genetic studies of ovulation have been limited. It has long been thought that the mechanism controlling ovulation is highly divergent due to speciation and fast evolution. Using genetic tools available in Drosophila, we now report that ovulation in Drosophila strongly resembles mammalian ovulation at both the cellular and molecular levels. Just one of up to 32 mature follicles per ovary pair loses posterior follicle cells (“trimming”) and protrudes into the oviduct, showing that a selection process prefigures ovulation. Follicle cells that remain after egg release form a “corpus luteum (CL)” at the end of the ovariole, develop yellowish pigmentation, and express genes encoding steroid hormone biosynthetic enzymes that are required for full fertility. Finally, matrix metalloproteinase 2 (Mmp2), a type of protease thought to facilitate mammalian ovulation, is expressed in mature follicle and CL cells. Mmp2 activity is genetically required for trimming, ovulation and CL formation. Our studies provide new insights into the regulation of Drosophila ovulation and establish Drosophila as a model for genetically investigating ovulation in diverse organisms, including mammals.

Sexual reproduction is thought to be a highly divergent process due to fast evolution and speciation. For example, sperm from one species can seldom fertilize eggs from another species, indicating that different molecular machinery for fertilization is applied in different species. In contrast to this divergent view, ovulation, the process of liberating mature eggs from the ovary, is a general phenomenon throughout the Metazoa. We provide evidence that basic mechanisms of ovulation are conserved. Like mammalian follicles, Drosophila follicles consist of single oocytes surrounded by a layer of follicle cells. Drosophila follicles degrade their posterior follicle cells to allow the oocyte to rupture into the oviduct during ovulation. The residual postovulatory follicles reside in the ovary, accumulate yellowish pigmentation, and produce the steroid hormone ecdysone, features which resemble the mammalian corpus luteum. We also showed that matrix metalloproteinase, a type of proteinase proposed to degrade the mammalian follicle wall during ovulation, is required in Drosophila for posterior follicle cell degradation and ovulation. These findings are particularly important because this simple genetic model system will speed up the identification of many conserved regulators required for regulating matrix metalloproteinase activity and ovulation in human, processes that influence ovarian cancer formation and cancer metastasis.

Progesterone receptor expression in granulosa cells is suppressed by microRNA-378-3p

In developing ovarian follicles, the progesterone receptor (PGR) is essential for mediating transcription of key factors that coordinate cellular functions including follicular remodeling. With recent investigations examining the role of microRNA (miRNA) in regulating ovarian function we used a lentiviral approach to over express miR-378 in cultured primary porcine granulosa cells to study the role this miRNA may play in granulosa cell development. We revealed that miR-378-3p decreased protein levels and mRNA levels of PGR via targeting its 3'UTR. We observed that this regulation of PGR by miR-378-3p resulted in a corresponding decrease in gene transcripts of ADAMTS1, CTSL1, and PPARG, all known to be regulated by PGR and important for follicular maturation and remodeling. Our study provides the first evidence for post-transcriptional regulation of PGR and further elucidates the role of miR-378-3p in the ovary.

Molecular cloning, characterization, and expression analysis of luteinizing hormone receptor gene in turbot (Scophthalmus maximus)

The luteinizing hormone receptor (LHR) plays a crucial role in female reproduction. In the present study, full-length sequence coding for the LHR was obtained from female turbot (Scophthalmus maximus) by homology cloning and a strategy based on rapid amplification of cDNA end-polymerase chain reaction. The full-length LHR cDNA was 3,184 bp long and contained a 2,058-bp open reading frame which encoded a protein of 685 amino acids. Multiple sequence alignments of the turbot LHR manifested high homologies with the corresponding sequences of available teleosts and representative vertebrates, and significant homology with that of Hippoglossus hippoglossus. In addition, the turbot LHR showed typical characteristics of glycoprotein receptors, including a long N-terminal extracellular domain, seven transmembrane domains, and a short C-terminal intracellular domain. LHR mRNA was abundant in the ovary, but was deficient in extra-ovarian tissues. Furthermore, LHR mRNA gradually developed from previtellogenesis to migratory nucleus stage, with the highest values observed in migratory nucleus stage during reproductive cycle. However, LHR mRNA sharply decreased in atresia stage. These results suggested that LHR is a typical G protein-coupled receptor that is involved in the promotion of turbot ovarian development and may be related to the final maturation and ovulation of oocyte. These findings contribute to the understanding of the potential roles of LHR in controlling the fish reproductive cycle.

1H-NMR metabolomic biomarkers of poor outcome after hemorrhagic shock are absent in hibernators

Background

Hemorrhagic shock (HS) following trauma is a leading cause of death among persons under the age of 40. During HS the body undergoes systemic warm ischemia followed by reperfusion during medical intervention. Ischemia/reperfusion (I/R) results in a disruption of cellular metabolic processes that ultimately lead to tissue and organ dysfunction or failure. Resistance to I/R injury is a characteristic of hibernating mammals. The present study sought to identify circulating metabolites in the rat as biomarkers for metabolic alterations associated with poor outcome after HS. Arctic ground squirrels (AGS), a hibernating species that resists I/R injury independent of decreased body temperature (warm I/R), was used as a negative control.

Methodology/principal findings

Male Sprague-Dawley rats and AGS were subject to HS by withdrawing blood to a mean arterial pressure (MAP) of 35 mmHg and maintaining the low MAP for 20 min before reperfusing with Ringers. The animals’ temperature was maintained at 37±0.5°C for the duration of the experiment. Plasma samples were taken immediately before hemorrhage and three hours after reperfusion. Hydrophilic and lipid metabolites from plasma were then analyzed via ¹H–NMR from unprocessed plasma and lipid extracts, respectively. Rats, susceptible to I/R injury, had a qualitative shift in their hydrophilic metabolic fingerprint including differential activation of glucose and anaerobic metabolism and had alterations in several metabolites during I/R indicative of metabolic adjustments and organ damage. In contrast, I/R injury resistant AGS, regardless of season or body temperature, maintained a stable metabolic homeostasis revealed by a qualitative ¹H–NMR metabolic profile with few changes in quantified metabolites during HS-induced global I/R.

Conclusions/significance

An increase in circulating metabolites indicative of anaerobic metabolism and activation of glycolytic pathways is associated with poor prognosis after HS in rats. These same biomarkers are absent in AGS after HS with warm I/R.

IGF1R signaling is necessary for FSH-induced activation of AKT and differentiation of human Cumulus granulosa cells

CONTEXT

FSH is routinely administered to in vitro fertilization patients to induce follicle maturation. During this process, granulosa cells differentiate and acquire specific functional characteristics that are required to coordinate ovulation and oocyte maturation.

OBJECTIVE

The objective of the study was to gain insight into the molecular mechanisms regulating human granulosa cell differentiation. Design, Setting, Patients, and Interventions: Cumulus and mural granulosa cells were isolated from the follicular aspirates of in vitro fertilization patients and analyzed immediately or cultured in serum-free media in the presence of FSH, IGFs, or an inhibitor of type I IGF receptor (IGF1R) activity.

MAIN OUTCOME

We quantified the mRNA and protein levels of steroidogenic enzymes, components of the IGF system, and gonadotropin receptors; measured 17β-estradiol levels; and examined the activation of intracellular signaling pathways to assess the granulosa cell differentiation as well as the FSH and IGF actions in both cumulus and mural cells.

RESULTS

In freshly isolated cells, LH receptor (Lhr) and steroidogenic acute regulator (Star) were expressed at lower levels in cumulus than mural cells, whereas FSH receptor (Fshr) and anti-Müllerian hormone (Amh) were expressed at higher levels in cumulus than mural cells. In vitro, the expression of Igf2, the differentiation markers Lhr, Star, and Cyp19a1 (aromatase) as well as 17β-estradiol production remained low in untreated cumulus cells but increased significantly after FSH treatment. Strikingly, this stimulatory effect of FSH was abolished by the inhibition of IGF1R activity. FSH-induced activation of v-akt murine thymoma viral oncogene homolog 3 (AKT) required IGF1R activity, and overexpression of constitutively active AKT rescued the induction of differentiation markers and 17β-estradiol production by FSH in the presence of the IGF1R inhibitor.

CONCLUSIONS

The cumulus cell response to FSH resembles the differentiation of preantral to preovulatory granulosa cells. This differentiation program requires IGF1R activity and subsequent AKT activation.

Ovarian membrane-type matrix metalloproteinases: induction of MMP14 and MMP16 during the periovulatory period in the rat, macaque, and human

An intrafollicular increase in proteolytic activity drives ovulatory events. Surprisingly, the periovulatory expression profile of the membrane-type matrix metalloproteinases (MT-MMPs), unique proteases anchored to the cell surface, has not been extensively examined. Expression profiles of the MT-MMPs were investigated in ovarian tissue from well-characterized rat and macaque periovulatory models and naturally cycling women across the periovulatory period. Among the six known MT-MMPs, mRNA expression of Mmp14, Mmp16, and Mmp25 was increased after human chorionic gonadotropin (hCG) administration in rats. In human granulosa cells, mRNA expression of MMP14 and MMP16 increased following hCG treatment. In contrast, mRNA levels of MMP16 and MMP25 in human theca cells were unchanged before ovulation but declined by the postovulatory stage. In macaque granulosa cells, hCG increased mRNA for MMP16 but not MMP14. Immunoblotting showed that protein levels of MMP14 and MMP16 in rats increased, similar to their mRNA expression. In macaque granulosa cells, only the active form of the MMP14 protein increased after hCG, unlike its mRNA or the proprotein. By immunohistochemistry, both MMP14 and MMP16 localized to the different ovarian cell types in rats and humans. Treatment with hCG resulted in intense immunoreactivity of MMP14 and MMP16 proteins in the granulosa and theca cells. The present study shows that MMP14 and MMP16 are increased by hCG administration in the ovulating follicle, demonstrating that these MMPs are conserved among rats, macaques, and humans. These findings suggest that MT-MMPs could have an important role in promoting ovulation and remodeling of the ovulated follicle into the corpus luteum.

Ovarian surface epithelium receptors during pregnancy and estrus cycle of rats with emphasis on steroids and gonadotropin fluctuation

The present study is designed to demonstrate the ovarian surface epithelial cells' (OSE) estrogen receptor α (ERα) and progesterone receptor (PR) during pregnancy and estrous cycle in rat. Moreover, determination of the levels of plasma progesterone, estradiol, FSH and LH was also made. The levels of plasma progesterone, estradiol, FSH and LH concentrations were determined on days 7 (n = 5), 14 (n = 5), and 21 (n = 5) of pregnancy in three groups of rats and during the estrous cycle (n = 5) using an ELISA kit. Immunohistochemical method for PR and ERα expressions was also made on the ovary. During pregnancy, FSH and LH remained low except at term when LH levels began to increase from 16 ng/ml to 47 ng/ml. Progesterone levels significantly exceeded estradiol values in all pregnant rats with a peak value of 202 ng/ml on day 14. Elevated progesterone levels were associated negatively with LH and estradiol levels during pregnancy. The levels of estradiol surged significantly on day 21. Immunohistochemistry of the ovary showed low levels of OSE cells staining positive for ERα expression. ERα positive cells were absent on day 7 and 14 of pregnancy, only day 21 recorded a very low percentage of immunostaining (0.5%) within the nuclei of OSE cells. On the contrary, immunostaining of PR was not observed within the nuclei of OSE cells in all groups of study. In conclusion, these results may suggest that the progesterone effect during pregnancy seems to be overriding the positive effect of estrogens on OSE cells. High progesterone levels may have a direct negative effect on gonadotropin production and thereby it might inhibit events leading to both follicular development and OSE proliferation. Understanding the factors affecting OSE proliferation may help elucidating the mechanism(s) of assisted diseases such as ovarian cancer.