Markers of stem cells in human ovarian granulosa cells: is there a clinical significance in ART?

AKT, p-AKT, ERK1/2 and p-ERK1/2 in Mural Granulosa Cells Are Not Correlated to Different Ovarian Stimulation Protocols in Patients Undergoing Assisted Reproductive Treatment

(1) Background: In this paper we aim to study the relationship between the expression levels of molecules involved in apoptotic/survival pathways, considered as molecular markers of oocyte competence (i.e., AKT, p-AKT, ERK1/2, and p-ERK1/2) in mural granulosa cells (MGCs) and the administration of r-FSH alone or combined with exogenous r-LH, in ovarian stimulation protocol. Moreover, we aim to evaluate oocyte competence by comparing normally cleaved embryos that were transferred in the uterus, with embryos that were arrested during in vitro culture. (2) Methods: The study included 34 normo-responder women undergoing ICSI procedures. All subjects were divided into two groups. Group A consisted of 18 women stimulated with r-FSH and used as a control group; Group B consisted of 14 women stimulated with r-FSH combined with r-LH. The MGCs were obtained from individual follicles. Immunoblot analyses were carried out to analyze the AKT, p-AKT, ERK1/2, and p-ERK1/2 levels in MGCs and to correlate them with the ovarian stimulation protocol. Furthermore, the oocyte competence was evaluated, for each follicle, according to the development of the embryo during in vitro culture and the pregnancy outcome. (3) Results: We found no significant difference in the levels of molecules in isolated MGCs between groups A and B. These results, in light of our previous research, suggest for the first time, to our knowledge, that cumulus cells and mural granulosa cells in the same follicle show different expression levels of molecules involved in the apoptotic mechanism. (4) Conclusions: Our results could clarify some controversial data in the literature where cumulative cell pools of cumulus and granulosa were analyzed, described as ovarian follicle cells, and used as markers of oocyte competence. In this paper, we found evidence that cumulus and granulosa cells need to be analyzed separately.

Combination of Estradiol with Leukemia Inhibitory Factor Stimulates Granulosa Cells Differentiation into Oocyte-Like Cells

Purpose: Previous studies have documented that cumulus granulosa cells (GCs) can trans-differentiation into different non-ovarian cells, showing their multipotentiality to repopulate the injured cells in ovarian tissue. The current experiment is aimed to assess the differentiation capacity of human cumulus GCs toward the oocyte-like phenotype in vitro.

Methods: GCs were isolated from healthy female volunteers subjected to in vitro fertilization or intra-cytoplasmic sperm injection (IVF-ICSI). The effect of different media supplemented with leukemia inhibitory factors (LIFs), 5 ng/mL estradiol, and 0.005 IU/mL follicle-stimulating hormone (FSH) were investigated to the differentiation of GCs toward oocyte-like phenotype via monitoring the expression of Oct3/4 and GATA-4 using flow cytometry analysis. The expression of genes such as FIGLA, NOBOX, and SYCP3 was measured by real-time polymerase chain reaction (PCR) assay. We also assess morphological adaptation by using bright-field microscopic imaging.

Results: Exposure of GCs to LIFs increased the number of cells expressing stemness factor Oct3/4 coincided with the suppression of GATA-4 after 7 days (P < 0.05). We found that the transcript level of all genes FIGLA, Nobox, and SYCP-3 decreased in cells after treatment with a FSH (P < 0.05). According to our data, the incubation of GCs with estradiol increased the expression of genes related to the oocyte-like phenotype.

Conclusion: Our finding revealed that the combination of LIFs and estradiol could induce the GCs’ oogenesis capacity and thereby is possibly suggested as a therapeutic strategy during the occurrence of gynecological disorders.

Mesenchymal Stem/Stromal Cells Derived from Human and Animal Perinatal Tissues-Origins, Characteristics, Signaling Pathways, and Clinical Trials

Mesenchymal stem/stromal cells (MSCs) are currently one of the most extensively researched fields due to their promising opportunity for use in regenerative medicine. There are many sources of MSCs, of which cells of perinatal origin appear to be an invaluable pool. Compared to embryonic stem cells, they are devoid of ethical conflicts because they are derived from tissues surrounding the fetus and can be safely recovered from medical waste after delivery. Additionally, perinatal MSCs exhibit better self-renewal and differentiation properties than those derived from adult tissues. It is important to consider the anatomy of perinatal tissues and the general description of MSCs, including their isolation, differentiation, and characterization of different types of perinatal MSCs from both animals and humans (placenta, umbilical cord, amniotic fluid). Ultimately, signaling pathways are essential to consider regarding the clinical applications of MSCs. It is important to consider the origin of these cells, referring to the anatomical structure of the organs of origin, when describing the general and specific characteristics of the different types of MSCs as well as the pathways involved in differentiation.

Stratifying Cumulus Cell Samples Based on Molecular Profiling to Help Resolve Biomarker Discrepancies and to Predict Oocyte Developmental Competence

To increase the efficiency of assisted reproductive techniques (ART), molecular studies have been performed to identify the best predictive biomarkers for selecting the most suitable germ cells for fertilization and the best embryo for intra-uterine transfer. However, across different studies, no universal markers have been found. In this study, we addressed this issue by generating gene expression and CpG methylation profiles of outer cumulus cells obtained during intra-cytoplasmic sperm injection (ICSI). We also studied the association of the generated genomic data with the clinical parameters (spindle presence, zona pellucida birefringence, pronuclear pattern, estrogen level, endometrium size and lead follicle size) and the pregnancy result. Our data highlighted the presence of several parameters that affect analysis, such as inter-individual differences, inter-treatment differences, and, above all, specific treatment protocol differences. When comparing the pregnancy outcome following the long protocol (GnRH agonist) of ovarian stimulation, we identified the single gene markers (NME6 and ASAP1, FDR < 5%) which were also correlated with endometrium size, upstream regulators (e.g., EIF2AK3, FSH, ATF4, MKNK1, and TP53) and several bio-functions related to cell death (apoptosis) and cellular growth and proliferation. In conclusion, our study highlighted the need to stratify samples that are very heterogeneous and to use pathway analysis as a more reliable and universal method for identifying markers that can predict oocyte development potential.

Characterization of stem cells from human ovarian follicular fluid; a potential source of autologous stem cell for cell-based therapy

Human ovarian follicular fluid (HOFF) contains proteins, extracellular matrixes necessary for growth and maturation of oocytes as well as granulosa cells. Epithelial cells and stem cells can be isolated from HOFF. However, information regarding stem cells derived from HOFF is still lacking. The objectives of the present study were to isolate, characterize, and differentiate cells derived from HOFF. HOFF was collected during the routine aspiration of oocytes in an assisted fertilization program and subjected to cell isolation, characterization, and in vitro culture. After 24 h of culture, different cell morphologies including epithelial-like-, neural-like- and fibroblast-like cells were observed. Immunocytochemistry reveals the expression of pluripotent stem cell markers (OCT4, NANOG, SSEA4), epithelial marker (CK18), FSH- and LH-receptor. For in vitro culture, the isolated cells were continuously cultured in a growth medium; alpha MEM containing 10% FBS and epidermal growth factor (EGF). After 2 weeks of in vitro culture, cells with fibroblast-like morphology dominantly grow in the culture vessels and resemble mesenchymal stem cells (MSCs). HOFF-derived cells exhibited MSC expression of CD44, CD73, CD90, CD105, CD146, and STRO-1, and were capable of differentiation into osteoblasts, chondrocytes, and adipocytes. After induction of neural differentiation, HOFF-derived cells formed spheroidal structures and expressed neural stem cell markers including Nestin, β-tubulin III, and O4. Besides, the oocyte-like structure was observed after prolonged culture of HOFF. In conclusion, cells derived from follicular fluid exhibited stem cell characteristics, which could be useful for regenerative medicine applications and cell-based therapies.

Reprogramming of Ovarian Granulosa Cells by YAP1 Leads to Development of High-Grade Cancer with Mesenchymal Lineage and Serous Features

Understanding the cell-of-origin of ovarian high grade serous cancer (HGSC) is the prerequisite for efficient prevention and early diagnosis of this most lethal gynecological cancer. Recently, a mesenchymal type of ovarian HGSC with the poorest prognosis among ovarian cancers was identified by both TCGA and AOCS studies. The cell-of-origin of this subtype of ovarian cancer is unknown. While pursuing studies to understand the role of the Hippo pathway in ovarian granulosa cell physiology and pathology, we unexpectedly found that the Yes-associated protein 1 (YAP1), the major effector of the Hippo signaling pathway, induced dedifferentiation and reprogramming of the ovarian granulosa cells, a unique type of ovarian follicular cells with mesenchymal lineage and high plasticity, leading to the development of high grade ovarian cancer with serous features. Our research results unveil a potential cell-of-origin for a subtype of HGSC with mesenchymal features.

Transcriptomic analysis of expression of genes regulating cell cycle progression in porcine ovarian granulosa cells during short-term in vitro primary culture

The primary function of ovarian granulosa cells (GCs) is the support of oocytes during maturation and development. Molecular analyses of granulosa cell-associated processes, leading to improvement of understanding of the cell cycle events during the formation of ovarian follicles (folliculogenesis), may be key to improve the in vitro fertilization procedures. Primary in vitro culture of porcine GCs was employed to examine the changes in the transcriptomic profile of genes belonging to “cell cycle”, “cell division”, “cell cycle process”, “cell cycle phase transition”, “cell cycle G1/S phase transition”, “cell cycle G2/M phase transition” and “cell cycle checkpoint” ontology groups. During the analysis, microarrays were employed to study the transcriptome of GCs, analyzing the total RNA of cells from specific periods of in vitro cultures. This research was based on material obtained from 40 landrace gilts of similar weight, age and the same living conditions. RNA was isolated at specific timeframes: before the culture was established (0 h) and after 48 h, 96 h and 144 h in vitro. Out of 133 differentially expressed genes, we chose the 10 most up-regulated (SFRP2, PDPN, PDE3A, FGFR2, PLK2, THBS1, ETS1, LIF, ANXA1, TGFB1) and the 10 most downregulated (IGF1, NCAPD2, CABLES1, H1FOO, NEK2, PPAT, TXNIP, NUP210, RGS2 and CCNE2). Some of these genes known to play key roles in the regulation of correct cell cycle passage (up-regulated SFRP2, PDE3A, PLK2, LIF and down-regulated CCNE2, TXNIP, NEK2). The data obtained provide a potential reference for studies on the process of mammalian folliculogenesis, as well as suggests possible new genetic markers for cell cycle progress in in vitro cultured porcine granulosa cells.

Evaluation of stemness marker expression in bovine ovarian granulosa cells

The objective of this study was to assess the stemness marker expressions (Oct4, Nanog, and Sox2) of granulosa cells (GCs) collected from bovine ovarian follicles and in vitro expansion. The single bovine ovarian follicles were isolated and categorized into 4 groups according to their diameter including group A (<2 mm), group B (2-3 mm), group C (3-4 mm), and group D (>4 mm). Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and immunostaining were applied to evaluate the stemness marker expression of bovine GCs from ovarian follicles. We also estimated the stemness marker transcript expressions of GCs during in vitro expression by qRT-PCR. qRT-PCR analysis demonstrated that fresh GCs from bovine ovarian follicles expressed the stemness markers (Oct4, Nanog, Sox2). These markers were down-regulated during antral stage follicular development. We also estimated stemness marker transcript expressions of GCs which were isolated and in vitro expanded from ovarian follicles of group A. The qRT-PCR results showed that Oct4 and Sox2 transcript expressions were reduced during in vitro expansion while Nanog transcript was not expressed.

Lats1 and Lats2 are required for ovarian granulosa cell fate maintenance

Recent reports suggest that the Hippo signaling pathway influences ovarian follicle development; however, its exact roles remain unknown. Here, we examined the ovarian functions of the Hippo kinases large tumor suppressors (LATS)1 and 2, which serve to inactivate the transcriptional coactivators Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). Inactivation of Lats1/2 in murine granulosa cells either in vitro or in vivo resulted in a loss of granulosa cell morphology, function, and gene expression. Mutant cells further underwent changes in structure and gene expression suggestive of epithelial-to-mesenchymal transition and transdifferentiation into multiple lineages. In vivo, granulosa cell-specific loss of Lats1/2 caused the ovarian parenchyma to be mostly replaced by bone tissue and seminiferous tubule-like structures. Transdifferentiation into Sertoli-like cells and osteoblasts was attributed in part to the increased recruitment of YAP and TAZ to the promoters of sex-determining region Y box 9 and bone γ-carboxyglutamate protein, key mediators of male sex determination and osteogenesis, respectively. Together, these results demonstrate for the first time a critical role for Lats1/2 in the maintenance of the granulosa cell genetic program and further highlight the remarkable plasticity of granulosa cells.-Tsoi, M., Morin, M., Rico, C., Johnson, R. L., Paquet, M., Gévry, N., Boerboom, D. Lats1 and Lats2 are required for ovarian granulosa cell fate maintenance.

Characterization and identification of human immortalized granulosa cells derived from ovarian follicular fluid

Follicular fluid serves a crucial role in follicular development and oocyte maturation. Increasing evidence indicates that follicular fluid is rich in proteins and functional cells. In addition to oocyte cells, follicular fluid contains granulosa, thecal and ovarian surface epithelial cells. Granulosa cells (GCs) represent the predominant somatic cell type of the ovarian follicle and are involved in steroidogenesis and folliculogenesis. However, the long-term culture of GCs in vitro remains challenging. The present study aimed to extend the culture of GCs in vitro. Human GCs were collected from the follicular fluid of patients included in an in vitro fertilization program and cultured in the presence of conditioned medium obtained from mouse embryonic fibroblasts. GCs were cultured for over a year and 130 passages, and the population doubling time was ~22 h. Cells presented epithelial-like morphology and a cobblestone-like appearance when they reached confluence. Flow cytometric analysis demonstrated that cells expressed CD29, CD166 and CD49f but not CD31, CD34, CD45, CD90, CD105 or CD13. Immunofluorescence staining revealed that cells expressed follicle stimulating hormone receptor, luteinizing hormone receptor and cytochrome P450 aromatase, which was confirmed by reverse transcription-quantitative polymerase chain reaction. In the presence of androstenedione, cells secreted estradiol. In addition, estradiol level was further stimulated by dibutyryl cAMP treatment. In addition, intracellular cAMP and progesterone expression levels were upregulated by follicle stimulating hormone and/or human chorionic gonadotropin. Furthermore, cells survived in severe combined immunodeficiency mice following intra-ovarian injection. Histological analysis revealed that certain cells formed follicle-like structures. The results from the present study suggested that immortalized GCs may be a useful tool for further research on GC and improve the clinical application of drugs such as follicle-stimulating hormone or human chorionic gonadotropin.

Female Age Affects the Mesenchymal Stem Cell Characteristics of Aspirated Follicular Cells in the In Vitro Fertilization Programme

Aspirated follicular cells (AFCs) from the in vitro fertilization program can express various stem cell markers and are even able to differentiate into different types of cells in vitro. The female reproductive potential decreases with increasing age due to lowered ovarian reserve and oocyte quality, but data on the effect of female age on stem cell characteristics of AFCs are scarce. Therefore, the aim of this study was to elucidate whether female age affects the mesenchymal stem cell (MSC) characteristics of AFCs. Follicular aspirates were collected from 12 patients included in the in vitro fertilization programme with a normal ovarian reserve. Patients were divided into four age groups: Group A ≤ 30 years, Group B 31-35 years, Group C 36-39 years and Group D ≥ 40 years. After removal of the oocytes, AFCs were collected from follicular aspirates using hypo-osmotic technique and cultured in vitro, and their stemness was compared according to female age. The cultured AFCs were analysed for gene expression using the Human Mesenchymal Stem Cell RT² Profiler™ PCR Array, for their potential for differentiation into adipogenic and osteogenic lineage, and for their expression of MSC-related markers using immunocytochemistry. We found that female age can significantly influence their stemness: expression of pluripotency and MSC-related genes, and their differentiation potential. Despite the relatively high expression of MSC-related genes, the AFCs of the oldest patients had the lowest potential to differentiate into osteogenic and adipogenic lineages in vitro, which may be related to their age and the changed ovarian function.

Distinct effect of fetal bovine serum versus follicular fluid on multipotentiality of human granulosa cells in in vitro condition

This study aimed to develop an appropriate medium for preservation of multipotentiality in human granulosa cells. To compare the possible effect of different media supplemented with follicular fluid or fetal bovine serum, granulosa cells were cultured in vitro over a period of 14 days. Stemness feature and any alteration in the cell phenotype were monitored using colony count assay and flow cytometry analysis by monitoring the expression of Oct3/4 and GATA-4 factors. Transcript expression level of Sox-2, Klf-4, and Nanog were investigated using quantitative real-time PCR analysis. Cells were cultured in the medium supplement with follicular fluid showed normal cell morphology and epithelial-like appearance, however, cells treated with fetal bovine serum, exhibited the clonogenic potential of granulosa cells which was increased after exposure to follicular fluid after 14 days (p < 0.05). Flow cytometry analysis revealed a significant reduction in the protein level of GATA-4 in cells cultured in presence of follicular fluid compared with cells received fetal bovine serum (p < 0.001). Quantitative real-time PCR analysis disclosed reduction of Sox-2, Klf-4 and Nanog levels in cells exposed to fetal bovine serum. Our experiment showed the exposure of human granulosa cells to follicular fluid efficiently preserves the stemness characteristics of the cells.

Ovarian regeneration: The potential for stem cell contribution in the postnatal ovary to sustained endocrine function

The endocrine function of the ovary is dependent upon the ovarian follicle, which on a cellular basis consists of an oocyte surrounded by adjacent somatic cells responsible for generating sex steroid hormones and maintenance of hormonal stasis with the hypothalamic-pituitary axis. As females age, both fertility and the endocrine function of the ovary decline due to waning follicle numbers as well as aging-related cellular dysfunction. Although there is currently no cure for ovarian failure and endocrine disruption, recent advances in ovarian biology centered on ovarian stem cell and progenitor cell populations have brought the prospects of cell- or tissue-based therapeutic strategies closer to fruition. Herein, we review the relative contributions of ovarian stem cells to ovarian function during the reproductive lifespan, and postulate steps toward the development of ovarian stem cell-based approaches to advance fertility treatments, and also importantly to provide a physiological long-term means of endocrine support.

Changes in the expression of OCT4 in mouse ovary during estrous cycle

The transcriptional factor OCT4 regulates pluripotency of stem cells and has an important role during oocyte growth. Whereas, its role has remained ambiguous in ovarian tissue during reproductive cycle. Therefore, this study was aimed to investigate the expression patterns of OCT4 in mouse ovaries during the normal estrous cycle. Adult National Medical Research Institute mice were classified as proestrous, estrous, metestrous and diestrous on the basis of vaginal smear cytology. Their ovaries were removed and the protein and gene expression levels of OCT4 were assessed using immunohistochemical staining and real-time quantitative reverse-transcription PCR, respectively. Immunohistochemical staining revealed the expression of OCT4 in the cytoplasm of corpus luteum cells. In the follicles, OCT4 was expressed in the cytoplasm of granulosa cells. Furthermore, the gene expression levels of OCT4 was significantly higher in the proestrous phase than in the other phases of the estrous cycle (p < 0.05). The results indicated that OCT4 gene expression levels are affected by the cyclic pattern of the estrous cycle.

Self-Organizing Feature Maps Identify Proteins Critical to Learning in a Mouse Model of Down Syndrome

Down syndrome (DS) is a chromosomal abnormality (trisomy of human chromosome 21) associated with intellectual disability and affecting approximately one in 1000 live births worldwide. The overexpression of genes encoded by the extra copy of a normal chromosome in DS is believed to be sufficient to perturb normal pathways and normal responses to stimulation, causing learning and memory deficits. In this work, we have designed a strategy based on the unsupervised clustering method, Self Organizing Maps (SOM), to identify biologically important differences in protein levels in mice exposed to context fear conditioning (CFC). We analyzed expression levels of 77 proteins obtained from normal genotype control mice and from their trisomic littermates (Ts65Dn) both with and without treatment with the drug memantine. Control mice learn successfully while the trisomic mice fail, unless they are first treated with the drug, which rescues their learning ability. The SOM approach identified reduced subsets of proteins predicted to make the most critical contributions to normal learning, to failed learning and rescued learning, and provides a visual representation of the data that allows the user to extract patterns that may underlie novel biological responses to the different kinds of learning and the response to memantine. Results suggest that the application of SOM to new experimental data sets of complex protein profiles can be used to identify common critical protein responses, which in turn may aid in identifying potentially more effective drug targets.

Granulosa cell-derived induced pluripotent stem cells exhibit pro-trophoblastic differentiation potential

Introduction

Human induced pluripotent stem cells (hiPSCs) have been derived from various somatic cell types. Granulosa cells, a group of cells which surround oocytes and are obtained from the (normally discarded) retrieved egg follicles of women undergoing infertility treatment, are a possible cell source for induced pluripotent stem cell (iPSC) generation. Here, we explored the possibility of using human granulosa cells as a donor cell type for iPSC reprogramming, and compared granulosa cell-derived iPSCs (iGRAs) with those derived from other cell sources, to determine the potential ability of iGRA differentiation.

Methods

Granulosa cells were collected from egg follicles retrieved from women undergoing infertility treatment. After short-term culture, the granulosa cells derived from different patients were mixed in culture, and infected with retroviruses encoding reprogramming factors. The resulting iPSC clones were selected and subjected to microsatellite DNA analysis to determine their parental origin. IGRAs were subjected to RT-PCR, immunofluorescence staining, and in vitro and in vivo differentiation assays to further establish their pluripotent characteristics.

Results

Microsatellite DNA analysis was used to demonstrate that hiPSCs with different parental origins can be simultaneously reprogrammed by retroviral transfection of a mixed human granulosa cell population obtained from multiple individuals. The iGRAs resemble human embryonic stem cells (hESCs) in many respects, including morphological traits, growth requirements, gene and marker expression profiles, and in vitro and in vivo developmental propensities. We also demonstrate that the iGRAs express low levels of NLRP2, and differentiating iGRAs possess a biased differentiation potential toward the trophoblastic lineage. Although NLRP2 knockdown in hESCs promotes trophoblastic differentiation of differentiating hESCs, it does not result in exit from pluripotency. These results imply that NLRP2 may play a role in regulating the trophoblastic differentiation of human pluripotent stem cells.

Conclusions

These findings provide a means of generating iPSCs from multiple granulosa cell populations with different parental origins. The ability to generate iPSCs from granulosa cells not only enables modeling of infertility-associated disease, but also provides a means of identifying potential clinical interventions through iPSC-based drug screening.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0005-5) contains supplementary material, which is available to authorized users.

Identification and characterization of epithelial cells derived from human ovarian follicular fluid

Introduction

Follicular fluid is important for follicular development and oocyte maturation. Evidence suggests that follicular fluid is not only rich in proteins but cells. Besides oocytes, the follicular fluid contains granulosa, thecal, and ovarian surface epithelial cells, and both granulosa and thecal cells are well-characterized. However, epithelial cells in follicular fluid are poorly studied. This study aims to isolate and characterize in vitro epithelial cells that originate from human ovarian follicular fluid retrieved in the assisted fertilization program.

Methods

Follicular fluid samples were collected from 20 women in the assisted reproduction program. Epithelial cells were characterized by flow cytometry assay, immunofluorescence staining, real-time PCR, and time lapse photography.

Results

Epithelial cell cultures were established from 18 samples. A small population of epithelial cells expresses germ-line stem cell markers, such as octamer-binding transcription factor 4 (OCT4), NANOG, and DEAD box polypeptide 4 (DDX4). In the epithelial cell culture system, oocyte-like cells formed spontaneously in vitro and expressed the following transcription markers: deleted in azoospermia-like (DAZL), developmental pluripotency associated protein 3 stella-related protein (STELLA), zona pellucida gene family C (ZPC), Syntaptonemal complex protein (SCP), and growth and differentiation factor 9 (GDF9). Some of the oocyte-like cells developed a zona pellucida-like structure. Both the symmetric and asymmetric division split of epithelial cells and early developing oocytes were observed using time lapse photography. Cell colonies were formed during epithelial culturing, which maintained and proliferated in an undifferentiated way on the feeder layer and expressed some pluripotency markers. These colonies differentiated in vitro into various somatic cell types in all three germ layers, but did not form teratoma when injected into immunodeficient mice. Furthermore, these epithelial cells could be differentiated directly to functional hepatocyte-like cells, which do not exist in ovarian tissues.

Conclusions

The epithelial cells derived from follicular fluid are a potential stem cell source with a pluripotent/multipotent character for safe application in oogenesis and regenerative medicine.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0004-6) contains supplementary material, which is available to authorized users.

Expression of mesenchymal stem cells-related genes and plasticity of aspirated follicular cells obtained from infertile women

After removal of oocytes for in vitro fertilization, follicular aspirates which are rich in somatic follicular cells are discarded in daily medical practice. However, there is some evidence that less differentiated cells with stem cell characteristics are present among aspirated follicular cells (AFCs). The aim of this study was to culture AFCs in vitro and to analyze their gene expression profile. Using the RT² Profiler PCR array, we investigated the expression profile of 84 genes related to stemness, mesenchymal stem cells (MCSs), and cell differentiation in AFCs enriched by hypoosmotic protocol from follicular aspirates of infertile women involved in assisted reproduction programme in comparison with bone marrow-derived mesenchymal stem cells (BM-MSCs) and fibroblasts. Altogether the expression of 57 genes was detected in AFCs: 16 genes (OCT4, CD49f, CD106, CD146, CD45, CD54, IL10, IL1B, TNF, VEGF, VWF, HDAC1, MITF, RUNX2, PPARG, and PCAF) were upregulated and 20 genes (FGF2, CASP3, CD105, CD13, CD340, CD73, CD90, KDR, PDGFRB, BDNF, COL1A1, IL6, MMP2, NES, NUDT6, BMP6, SMURF2, BMP4, GDF5, and JAG1) were downregulated in AFCs when compared with BM-MSCs. The genes which were upregulated in AFCs were mostly related to MSCs and connected with ovarian function, and differed from those in fibroblasts. The cultured AFCs with predominating granulosa cells were successfully in vitro differentiated into adipogenic-, osteogenic-, and pancreatic-like cells. The upregulation of some MSC-specific genes and in vitro differentiation into other types of cells indicated a subpopulation of AFCs with specific stemness, which was not similar to those of BM-MSCs or fibroblasts.

A comparison of the multiple oocyte maturation gene expression patterns between the newborn and adult mouse ovary

BACKGROUND

The interaction between follicular cells and oocyte leads to a change in gene expression involved in oocyte maturation processes.

OBJECTIVE

The purpose of this study was to quantify the expression of more common genes involved in follicular growth and oocyte developmental competence.

MATERIALS AND METHODS

In this experimental study, the expression of genes was evaluated with qRT-PCR assay in female BALB/c mice pups at 3-day of pre-pubertal and 8 week old virgin adult ovaries. The tissue was prepared by H&E staining for normal morphological appearance. The data were calculated with the 2-∆Ct formula and assessed using non-parametric two-tailed Mann-Whitney test. The p<0.05 was considered as significant.

RESULTS

The data showed a significant increase in the level of Stra8 and GDF9 in adult compared with newborn mice ovaries (p=0.049). In contrast, a significant decrease in the level of Mvh, REC8, SCP1, SCP3, and ZP2 was observed in adult mice ovaries compared to those in the newborn mice ovaries (all p=0.049 except SCP1: p=0.046). There was no significant difference in the level of OCT4 and Cx37 expression between adult and newborn mice ovaries.

CONCLUSION

The modifications in gene expression patterns coordinate the follicular developmental processes. Furthermore, the findings showed higher expression level of premeiotic gene (Stra8) and lower level of meiotic entry markers (SCP1, SCP3, and REC8) in juvenile than newborn mouse ovaries. This article extracted from Ph.D. thesis. (Nehleh Zarei fard).

Plasticity of granulosa cells: on the crossroad of stemness and transdifferentiation potential

The ovarian follicle represents the basic functional unit of the ovary and consists of an oocyte, which is surrounded by granulosa cells (GCs). GCs play an important role in the growth and development of the follicle. They are subject to increased attention since it has recently been shown that the subpopulation of GCs within the growing follicle possesses exceptionally plasticity showing stem cell characteristics. In assisted reproduction programs, oocytes are retrieved from patients together with GCs, which are currently discarded daily, but could be an interesting subject to be researched and potentially used in regenerative medicine in the future. Isolated GCs expressed stem cell markers such as OCT-4, NANOG and SOX-2, showed high telomerase activity, and were in vitro differentiated into other cell types, otherwise not present within ovarian follicles. Recently another phenomenon demonstrated in GCs is transdifferentiation, which could explain many ovarian pathological conditions. Possible applications in regenerative medicine are also given.