Project description:Follicular somatic cells (mural granulosa cells and cumulus cells) and the oocyte communicate through paracrine interactions and through direct gap junctions between oocyte and cumulus cells. Considering that mural and cumulus cells arise through a common developmental pathway and that their differentiation is essential to reproductive success, understanding how these cells differ is a key aspect to understanding their critical functions. Changes in global gene expression before and after an ovulatory stimulus were compared between cumulus and mural granulosa cells to test the hypothesis that mural and cumulus cells are highly differentiated at the time of an ovulatory stimulus and further differentiate during the periovulatory interval. The transcriptomes of the two cell types were markedly different (>1500 genes) before an ovulatory hCG bolus but converged after ovulation to become completely overlapping. The predominant transition was for the cumulus cells to become more like mural cells after hCG. This indicates that the differentiated phenotype of the cumulus cell is not stable and irreversibly established but may rather be an ongoing physiological response to the oocyte. We compared transcriptomes of mural granulosa cells isolated from the follicles before (PM-GC) and after (VVM-GC) an ovulatory stimulus. These data were analyzed with previously published cumulus cells data to compare transitions in granulosa cell state before and after an ovulatory stimulus with transitions in cumulus cells.
Project description:The antral follicle stage plays a crucial role in mammalian oocyte maturation, signifying the final stages of oocyte development and ovulation. This complex process relies on synchronized interactions between oocyte maturation and the proliferation of neighboring granulosa cells. Previous studies have identified two subtypes of granulosa cells in antral follicles: cumulus granulosa cells, located in the inner region, which surround and support the oocyte, and mural granulosa cells, present in the outer layers, which provide mechanical support to the follicular wall and possess steroidogenic functions. Despite the wealth of molecular data generated by these studies, many fundamental questions regarding key developmental events, granulosa cell heterogeneity, functional annotation, and the intricate relationship between somatic cells and oocytes still lack detailed, single-cell resolution-level investigations. In this study, we isolated follicular cells from porcine antral follicles and conducted scRNA-seq to analyze the single-cell transcriptomes of these cells. By identifying and sub-clustering ovarian cells, such as mural granulosa cells and cumulus granulosa cells, we elucidated the heterogeneity of granulosa cells in pigs.
Project description:This group consist of human embryologists from the reproductive medical center for of the 1st affiliated hospital of Anhui Medical University. Our research is specifically focused on women ovarian reserve and the relevant female infertility. By deep sequencing, the current experiment determined the small non-coding RNA profile of cumulus cells from patients with or without diminished ovarian reserve undergoing controlled ovarian stimulation and in vitro fertilization treatment. Ovarian follicles, which are a densely-packed shell of granulosa cells that contains an immature or mature oocyte, are above all responsible for the development, maturation, and release of mature egg for fertilization. They are also responsible for synthesizing and secreting hormones that are essential for follicular development, menstrual and estrous cycle, maintenance of the reproductive tracts and their functions, development of female secondary sex characteristics, and metabolism. During folliculogenesis, ovarian granulosa cells surrounding the oocyte differentiate into mural granulosa cells, involved in gonadal steroidogenesis, and into cumulus cells, which are ovulated with the oocyte at ovulation. In the present study, we described the small non-coding RNA expression profile to characterize the ensemble of both known and novel ncRNAs expressed in cumulus cells from patients with or without Diminished ovarian reserve, by using high-throughput Solexa technology.
Project description:The granulosa cells in the mammalian ovarian follicle respond to gonadotropin signalling and are involved in the processes of folliculogenesis and oocyte maturation. Studies on gene expression and regulation in human granulosa cells are of interest due to their potential for estimating the oocyte viability and IVF success. The current study determined the mRNA profile by deep sequencing of the two intrafollicular somatic cell types: mural and cumulus granulosa cells isolated from women undergoing controlled ovarian stimulation and in vitro fertilization. Paired cumulus and mural granulosa samples were analysed from 3 women participating in IVF procedure. Differential gene expression study was performed. The identified gene expression profile was also used for predicting targets for miRNAs that were also identified from the same samples (GSE46489).
Project description:WNT4 is required for normal ovarian follicle development and female fertility in mice, but how its signal is transduced remains unknown. Fzd1 encodes a WNT receptor whose expression is markedly induced in both mural granulosa cells and cumulus cells during the preovulatory period, in a manner similar to Wnt4. To study the physiological roles of FZD1 in ovarian physiology and to determine if it serves as receptor for WNT4, Fzd1-null mice were created by gene targeting. Whereas rare Fzd1-/- females were sterile due to uterine fibrosis and ovarian tubulostromal hyperplasia, the majority were subfertile, producing M-bM-^IM-^H1 less pup per litter on average relative to controls. Unlike WNT4-deficient mice, ovaries from Fzd1-/- mice had normal weights, numbers of follicles, steroid hormone production and WNT4 target gene expression levels. Microarray analyses of granulosa cells from periovulatory follicles revealed few genes whose expression was altered in Fzd1-/- mice. However, gene expression analyses of cumulus-oocyte complexes (COCs) revealed a blunted response of both oocyte (Zp3, Dppa3, Nlrp5, Bmp15) and cumulus (Btc, Ptgs2, Sema3a, Ptx3, Il6, Nts, Alcam, Cspg2) genes to the ovulatory signal, whereas the expression of these genes was not altered in WNT4-deficient COCs from Wnt4tm1.1Boer/tm1.1Boer;Tg(CYP19A1-cre)1Jri mice. Despite altered gene expression, cumulus expansion appeared normal in Fzd1-/- COCs both in vitro and in vivo. Together, these results indicate that Fzd1 is required for normal female fertility and may act in part to regulate oocyte maturation and cumulus cell function, but is unlikely to function as the sole ovarian WNT4 receptor. Triplicate RNA samples from granulosa cells of Fzd1 KO mice are compared to triplicate RNA samples from granulosa cells of control Fzd1 WT mice
Project description:The granulosa cells in the mammalian ovarian follicle respond to gonadotropin signalling and are involved in the processes of folliculogenesis and oocyte maturation. Studies on gene expression and regulation in human granulosa cells are of interest due to their potential for estimating the oocyte viability and IVF success. However, the post-transcriptional gene expression studies on miRNA level in the human ovary have been scarce. The current study determined the miRNA profile by deep sequencing of the two intrafollicular somatic cell types: mural and cumulus granulosa cells isolated from women undergoing controlled ovarian stimulation and in vitro fertilization. Paired cumulus and mural granulosa samples were analysed from 3 women participating in IVF procedure. Libraries of all 6 samples were sequenced twice, generating 2 technical replicates for each sample. Differential gene expression study was performed on the pooled results of technical replicates.
Project description:Female fertility is determined in part by the size and development of the primordial follicle pool. The current study investigates the role of glial cell-line derived neurotrophic factor (GDNF) in the regulation of primordial follicle development in the ovary. Ovaries from four-day old female rat pups were maintained in organ culture for ten days in the absence (control) or presence of GDNF or kit ligand/stem cell factor (KL). Ovaries treated with GDNF contained a significant increase in developing follicles, similar to that observed with KL treatment previously shown to promote follicle development. The actions of GDNF on the ovarian transcriptome were investigated with a microarray analysis. Immunohistochemical studies demonstrated that GDNF is localized to oocyte cytoplasm in follicles of all developmental stages, as well as to cumulus granulosa cells and theca cells in antral follicles. GDNF receptor alpha 1 (GFRalpha1) staining was localized to oocyte cytoplasm of primordial and primary follicles, and at reduced levels in oocytes of antral follicles. GFRalpha1 was present in mural granulosa cells of antral follicles, theca cells, and the ovarian surface epithelium. The localization studies were confirmed with molecular analysis. Microarray analysis was used to identify changes in the ovarian transcriptome and further elucidate the signaling network regulating early follicle development. Observations indicate that GDNF promotes primordial follicle development and mediates autocrine and paracrine cell-cell interactions required during folliculogenesis. In contrast to the testis, ovarian GDNF is predominantly produced by germ cells (oocytes) rather than somatic cells. Experiment Overall Design: RNA samples from two control groups (pooled untreated cultured ovaries) are compared to two treated groups (pooled cultured ovaries treated with GDNF)
Project description:Cumulus cells and mural granulosa cells (MGCs) are spatially and functionally distinct cell types in antral follicles: cumulus cells contact the oocyte and most MGCs contact the basal lamina. For transcriptomic analyses, both cell types were collected from small and large antral follicles, before and after stimulation of immature mice with eCG, respectively. Both cell types underwent dramatic transcriptomic changes and the differences between them became greater with follicular growth. Although cumulus cells of both stages of follicular development are competent to undergo expansion in vitro, they were otherwise remarkably dissimilar with transcriptomic changes quantitatively equivalent to those of MGCs. Gene Ontology (GO) analysis showed that cumulus cells of small follicles were enriched in transcripts generally associated with catalytic components of metabolic processes while those from large follicles were involved in regulation of metabolism, cell differentiation, and adhesion. Upon contrasting cumulus cells versus MGCs, cumulus cells were enriched in transcripts associated with metabolism and cell proliferation while MGCs were enriched for transcripts involved in cell signaling and differentiation.
Project description:We are human embryologists from center for reproductive medicinel of Anhui Provincial Hospital Affiliated to Anhui Medical University, and we have the expertise to do all that properly in humans. By deep sequencing, the current experiment determined the miRNA profile of two intrafollicular somatic cell types: CRCs and COCs, isolated from women undergoing controlled ovarian stimulation and in vitro fertilization treatment. Ovarian follicles, which are a densely-packed shell of granulosa cells that contains an immature or mature oocyte, are above all responsible for the development, maturation, and release of mature egg for fertilization. They are also responsible for synthesizing and secreting hormones that are essential for follicular development, menstrual and estrous cycle, maintenance of the reproductive tracts and their functions, development of female secondary sex characteristics, and metabolism. During folliculogenesis, ovarian granulosa cells surrounding the oocyte differentiate into mural granulosa cells, involved in gonadal steroidogenesis, and into cumulus cells, which are ovulated with the oocyte at ovulation. These cumulus cells derive from the same population of early follicles, but differentiate into two distinct groups of cells: 1) Those directly lie on the zona pellucida are composed of the so called corona radiata cells.(CRCs) 2) The other group surrounds the CRCs and consists of more numerous cells, forming the so called cumulus oophorus cells (COCs). In the present study, we described the miRNA expression profile to characterize the ensemble of both known and novel miRNAs expressed in CRCs, as well as in COCs, by using high-throughput Solexa technology.