Follicle Online: an integrated database of follicle assembly, development and ovulation

Bovine models for human ovarian diseases

During early embryonic development, late fetal growth, puberty, adult reproductive years, and advanced aging, bovine and human ovaries closely share molecular pathways and hormonal signaling mechanisms. Other similarities between these species include the size of ovaries, length of gestation, ovarian follicular and luteal dynamics, and pathophysiology of ovarian diseases. As an economically important agriculture species, cattle are a foundational species in fertility research with decades of groundwork using physiologic, genetic, and therapeutic experimental techniques. Many technologies used in modern reproductive medicine, such as ovulation induction using hormonal therapy, were first used in cows before human trials. Human ovarian diseases with naturally occurring bovine correlates include premature ovary insufficiency (POI), polycystic ovarian syndrome (PCOS), and sex-cord stromal tumors (SCSTs). This article presents an overview of bovine ovary research related to causes of infertility, ovarian diseases, diagnostics, and therapeutics, emphasizing where the bovine model can offer advantages over other lab animals for translational applications.

Research Progress on the Treatment of Premature Ovarian Failure Using Mesenchymal Stem Cells: A Literature Review

Premature ovarian failure (POF) has become one of the main causes of infertility in women of childbearing age and the incidence of POF is increasing year by year, seriously affecting the physical and mental health of patients and increasing the economic burden on families and society as a whole. The etiology and pathogenesis of POF are complex and not very clear at present. Currently, hormone replacement therapy is mainly used to improve the symptoms of low estrogen, but cannot fundamentally solve the fertility problem. In recent years, stem cell (SC) transplantation has become one of the research hotspots in the treatment of POF. The results from animal experiments bring hope for the recovery of ovarian function and fertility in patients with POF. In this article, we searched the published literature between 2000 and 2020 from the PubMed database (https://pubmed.ncbi.nlm.nih.gov), and summarized the preclinical research data and possible therapeutic mechanism of mesenchymal stem cells (MSCs) in the treatment of POF. Our aim is to provide useful information for understanding POF and reference for follow-up research and treatment of POF.

The ReproGenomics Viewer: a multi-omics and cross-species resource compatible with single-cell studies for the reproductive science community

MOTIVATION

Recent advances in transcriptomics have enabled unprecedented insight into gene expression analysis at a single-cell resolution. While it is anticipated that the number of publications based on such technologies will increase in the next decade, there is currently no public resource to centralize and enable scientists to explore single-cell datasets published in the field of reproductive biology.

RESULTS

Here, we present a major update of the ReproGenomics Viewer, a cross-species and cross-technology web-based resource of manually-curated sequencing datasets related to reproduction. The redesign of the ReproGenomics Viewer's architecture is accompanied by significant growth of the database content including several landmark single-cell RNA-sequencing datasets. The implementation of additional tools enables users to visualize and browse the complex, high-dimensional data now being generated in the reproductive field.

AVAILABILITY AND IMPLEMENTATION

The ReproGenomics Viewer resource is freely accessible at http://rgv.genouest.org. The website is implemented in Python, JavaScript and MongoDB, and is compatible with all major browsers. Source codes can be downloaded from https://github.com/fchalmel/RGV.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Transcript abundance of stromal and thecal cell related genes during bovine ovarian development

Movement and expansion of mesonephric-derived stroma appears to be very important in the development of the ovary. Here, we examined the expression of 24 genes associated with stroma in fetal ovaries during gestation (n = 17; days 58-274) from Bos taurus cattle. RNA was isolated from ovaries for quantitative RT-PCR. Expression of the majority of genes in TGFβ signalling, stromal transcription factors (NR2F2, AR), and some stromal matrix genes (COL1A1, COL3A1 and FBN1, but not FBN3) showed a positive linear increase with gestational age. Expression of genes associated with follicles (INSL3, CYP17A1, CYP11A1 and HSD3B1), was low until mid-gestation and then increased with gestational age. LHCGR showed an unusual bimodal pattern; high levels in the first and last trimesters. RARRES1 and IGFBP3 also increased with gestational age. To relate changes in gene expression in stromal cells with that in non stromal cells during development of the ovary we combined the data on the stromal genes with another 20 genes from non stromal cells published previously and then performed hierarchical clustering analysis. Three major clusters were identified. Cluster 1 genes (GATA4, FBN3, LHCGR, CYP19A1, ESR2, OCT4, DSG2, TGFB1, CCND2, LGR5, NR5A1) were characterised by high expression only in the first trimester. Cluster 2 genes (FSHR, INSL3, HSD3B1, CYP11A1, CYP17A1, AMH, IGFBP3, INHBA) were highly expressed in the third trimester and largely associated with follicle function. Cluster 3 (COL1A1, COL3A1, FBN1, TGFB2 TGFB3, TGFBR2, TGFBR3, LTBP2, LTBP3, LTBP4, TGFB1I1, ALDH1A1, AR, ESR1, NR2F2) had much low expression in the first trimester rising in the second trimester and remaining at that level during the third trimester. Cluster 3 contained members of two pathways, androgen and TGFβ signalling, including a common member of both pathways namely the androgen receptor cofactor TGFβ1 induced transcript 1 protein (TGFB1I1; hic5). GATA4, FBN3 and LHCGR, were highly correlated with each other and were expressed highly in the first trimester during stromal expansion before follicle formation, suggesting that this could be a critical phase in the development of the ovarian stroma.

Increased Formation of Follicular Antrum in Aquaporin-8-Deficient Mice Is Due to Defective Proliferation and Migration, and Not Steroidogenesis of Granulosa Cells

Aquaporin-8 (AQP8) is a water channel protein expressed exclusively in granulosa cells (GCs) in mouse ovary. Our previous studies of AQP8-deficient (AQP8^-/-) mice demonstrated that AQP8 participates in folliculogenesis, including in the formation of follicles, ovulation, and atresia. However, its physiological function in formation of the antral follicle is still largely unknown. In the present study, we observed significantly increased numbers of antral follicles in AQP8^-/- ovaries as well as significantly increased follicular antrum formation in in vitro 3D culture of AQP8^-/- follicles. Functional detection of AQP8^-/- GCs indicated that cell proliferation is impaired with FSH treatment, and wound healing and Transwell migration are also impaired with or without FSH treatment, compared with that in WT. However, the biosynthesis of estradiol and progesterone as well as the mRNA levels of key steroidogenic enzyme genes (CYP19A1 and StAR) in AQP8^-/- GCs did not change, even with addition of FSH and/or testosterone. In order to estimate the influence of the impaired proliferation and migration on the density of GC mass, preantral follicles were injected with FITC-dextran, which distributes only in the intercellular space, and analyzed by confocal microscopy. The micrographs showed significantly higher transmission of fluorescence in AQP8^-/- follicles, suggesting increased intercellular space of GCs. Based on this evidence, we concluded that AQP8 deficiency leads to increased formation of follicular antra in vivo and in vitro, and the mechanism may be associated with increased intercellular space of GCs, which may be caused by defective proliferation and migration of GCs. This study may offer new insight into the molecular mechanisms of the formation of follicular antrum.

Dynamic and modular gene regulatory networks drive the development of gametogenesis

Gametogenesis is a complex process, which includes mitosis and meiosis and results in the production of ovum and sperm. The development of gametogenesis is dynamic and needs many different genes to work synergistically, but it is lack of global perspective research about this process. In this study, we detected the dynamic process of gametogenesis from the perspective of systems biology based on protein-protein interaction networks (PPINs) and functional analysis. Results showed that gametogenesis genes have strong synergistic effects in PPINs within and between different phases during the development. Addition to the synergistic effects on molecular networks, gametogenesis genes showed functional consistency within and between different phases, which provides the further evidence about the dynamic process during the development of gametogenesis. At last, we detected and provided the core molecular modules of different phases about gametogenesis. The gametogenesis genes and related modules can be obtained from our Web site Gametogenesis Molecule Online (GMO, http://gametsonline.nwsuaflmz.com/index.php), which is freely accessible. GMO may be helpful for the reference and application of these genes and modules in the future identification of key genes about gametogenesis. Summary, this work provided a computational perspective and frame to the analysis of the gametogenesis dynamics and modularity in both human and mouse.

[Ovarian failure: New treatments in perspective?]

The premature loss of ovarian function may have physical and psychological consequences. A better understanding of its mechanism is therefore needed. Because they are affecting the oocyte quality, the decline of the ovarian reserve and high maternal age are implicated in many defects leading to chromosomal defects, modifications of gene expression or alterations of the mitochondrial pattern of the oocyte. However, cellular therapies such as ovarian follicle activation or isolation of ovarian stem cells are promising treatments of ovarian failure.