126. JAK/STAT SIGNALLING IN FOLLICULOGENESIS

2010 ◽  
Vol 22 (9) ◽  
pp. 44 ◽  
Author(s):  
J. M. Sutherland ◽  
R. Keightley ◽  
R. L. Robker ◽  
D. L. Russell ◽  
E. A. McLaughlin
Keyword(s):  
Target Genes ◽  
Ovarian Follicle ◽  
Current Model ◽  
Primordial Follicle ◽  
Neonatal Mouse ◽  
Signalling Pathway ◽  
Janus Kinase ◽  
Primordial Follicles ◽  
Primordial Follicle Activation ◽  
Follicle Activation

Primordial follicle activation marks the first stage of pre-pubertal ovarian folliculogenesis, and is therefore fundamental to female fertility. Entry into development is initiated by a group of pleiotropic cytokines and growth factors, originating in and acting upon both the oocyte and granulosa support cells of the ovarian follicle through the Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signalling pathway. Pivotal to this process is the transcriptional regulation of target genes via STAT complexes and negative regulation by the Suppressors of Cytokine Signalling (SOCS) family of proteins. Preliminary evidence indicates that STAT3 facilitates the activation of primordial follicles, while SOCS4 counterbalances the activity of STAT3, mediating the controlled release of primordial follicles into the growing pool throughout reproductive life. Leukemia Inhibitory Factor (LIF) has been previously demonstrated as a key granulosa cell derived cytokine involved in inducing primordial follicle activation. Through both quantitative gene expression (qPCR) and immunoblotting we have demonstrated that LIF can significantly upregulate STAT3 mRNA production (~2-fold) as well as increase STAT3 protein phosphorylation within neonatal mouse ovarian explants culture. Furthermore, through the generation of a recombinant SOCS4 protein construct, and its use in subsequent protein-protein pull-downs, we were able to multiple targets involved in oocyte maturation, STAT3 interactions, and JAK/STAT signaling. These targets were also found to be significantly upregulated via qPCR analysis in neonatal mouse ovaries treated with LIF. These results support our current model for the involvement of STAT3 and SOCS4 in a basic negative feedback loop within the JAK/STAT signalling pathway that results in the regulation of primordial follicle activation and development.

scholarly journals Peroxisome Proliferator-Activated Receptor Gamma Modulator Promotes Neonatal Mouse Primordial Follicle Activation In Vitro

2020 ◽  
Vol 21 (9) ◽  
pp. 3120
Author(s):  
Sook Young Yoon ◽  
Ran Kim ◽  
Hyunmee Jang ◽  
Dong Hyuk Shin ◽  
Jin Il Lee ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Primordial Follicle ◽  
Neonatal Mouse ◽  
Peroxisome Proliferator ◽  
Follicle Growth ◽  
Peroxisome Proliferator Activated Receptor ◽  
Primordial Follicles ◽  
Primordial Follicle Activation ◽  
Follicle Activation

Peroxisome proliferator-activated receptor gamma (PPARγ) is known as a regulator of cellular functions, including adipogenesis and immune cell activation. The objectives of this study were to investigate the expression of PPARγ and identify the mechanism of primordial follicle activation via PPARγ modulators in mouse ovaries. We first measured the gene expression of PPARγ and determined its relationship with phosphatase and tensin homolog (PTEN), protein kinase B (AKT1), and forkhead box O3a (FOXO3a) expression in neonatal mouse ovaries. We then incubated neonatal mouse ovaries with PPARγ modulators, including rosiglitazone (a synthetic agonist of PPARγ), GW9662 (a synthetic antagonist of PPARγ), and cyclic phosphatidic acid (cPA, a physiological inhibitor of PPARγ), followed by transplantation into adult ovariectomized mice. After the maturation of the transplanted ovaries, primordial follicle growth activation, follicle growth, and embryonic development were evaluated. Finally, the delivery of live pups after embryo transfer into recipient mice was assessed. While PPARγ was expressed in ovaries from mice of all ages, its levels were significantly increased in ovaries from 20-day-old mice. In GW9662-treated ovaries in vitro, PTEN levels were decreased, AKT was activated, and FOXO3a was excluded from the nuclei of primordial follicles. After 1 month, cPA-pretreated, transplanted ovaries produced the highest numbers of oocytes and polar bodies, exhibited the most advanced embryonic development, and had the greatest blastocyst formation rate compared to the rosiglitazone- and GW9662-pretreated groups. Additionally, the successful delivery of live pups after embryo transfer into the recipient mice transplanted with cPA-pretreated ovaries was confirmed. Our study demonstrates that PPARγ participates in primordial follicle activation and development, possibly mediated in part by the PI3K/AKT signaling pathway. Although more studies are required, adapting these findings for the activation of human primordial follicles may lead to treatments for infertility that originates from poor ovarian reserves.

Differentially Expressed lncRNAs After the Activation of Primordial Follicles in Mouse

2018 ◽  
Vol 26 (8) ◽  
pp. 1094-1104
Author(s):  
Liping Zheng ◽  
Ruichen Luo ◽  
Tie Su ◽  
Liaoliao Hu ◽  
Fengxin Gao ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Expression Profiles ◽  
Ovarian Follicle ◽  
Primordial Follicle ◽  
Differentially Expressed ◽  
Ovary Development ◽  
Primordial Follicles ◽  
Primordial Follicle Activation ◽  
Follicle Activation

The activation of primordial follicles is critical to ovarian follicle development, which directly influences female fertility and reproductive life span. Several studies have suggested a role for long noncoding RNAs (lncRNAs) in ovarian function. However, the precise involvement of lncRNAs in the initiation of primordial follicles is still unknown. Here, an in vitro culture model was used to investigate the roles of lncRNAs in primordial follicle activation. We found that primordial follicles in day 3 mouse ovaries were activated after culturing for 8 days in vitro, as indicated by ovarian morphology changes, increases in primary follicle number, and downregulation of mammalian Sterile 20-like kinase messenger RNA (mRNA) and upregulation of growth differentiation factor 9 mRNA. We next examined lncRNA expression profiles by RNA sequencing at the transcriptome level and found that among 60 078 lncRNAs, 6541 lncRNA were upregulated and 2135 lncRNA were downregulated in 3-day ovaries cultured for 8 days in vitro compared with ovaries from day 3 mice. We also found that 4171 mRNAs were upregulated and 1795 were downregulated in the cultured ovaries. Gene ontology and pathway analyses showed that the functions of differentially expressed lncRNA targets and mRNAs were closely linked with many processes and pathways related to ovary development, including cell proliferation and differentiation, developmental processes, and other signaling transduction pathways. Additionally, many novel identified lncRNAs showed inducible expression, suggesting that these lncRNAs may be good candidates for investigating mouse primordial follicle activation. This study provides a foundation for further exploring lncRNA-related mechanisms in the initiation of mouse primordial follicles.

scholarly journals Crosstalk between PTEN/PI3K/Akt Signalling and DNA Damage in the Oocyte: Implications for Primordial Follicle Activation, Oocyte Quality and Ageing

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 200 ◽  
Author(s):  
Mila Maidarti ◽  
Richard A. Anderson ◽  
Evelyn E. Telfer
Keyword(s):  
Dna Damage ◽  
Primordial Follicle ◽  
Oocyte Quality ◽  
Signalling Pathway ◽  
Phosphatase And Tensin Homolog ◽  
Primordial Follicles ◽  
Tensin Homolog ◽  
Primordial Follicle Activation ◽  
Growth Activation ◽  
Follicle Activation

The preservation of genome integrity in the mammalian female germline from primordial follicle arrest to activation of growth to oocyte maturation is fundamental to ensure reproductive success. As oocytes are formed before birth and may remain dormant for many years, it is essential that defence mechanisms are monitored and well maintained. The phosphatase and tensin homolog of chromosome 10 (PTEN)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB, Akt) is a major signalling pathway governing primordial follicle recruitment and growth. This pathway also contributes to cell growth, survival and metabolism, and to the maintenance of genomic integrity. Accelerated primordial follicle activation through this pathway may result in a compromised DNA damage response (DDR). Additionally, the distinct DDR mechanisms in oocytes may become less efficient with ageing. This review considers DNA damage surveillance mechanisms and their links to the PTEN/PI3K/Akt signalling pathway, impacting on the DDR during growth activation of primordial follicles, and in ovarian ageing. Targeting DDR mechanisms within oocytes may be of value in developing techniques to protect ovaries against chemotherapy and in advancing clinical approaches to regulate primordial follicle activation.

scholarly journals In-vitro fragmentation of ovarian tissue activates primordial follicles through the Hippo pathway

2020 ◽  
Vol 2020 (4) ◽  
Author(s):  
C De Roo ◽  
S Lierman ◽  
K Tilleman ◽  
P De Sutter
Keyword(s):  
Tissue Culture ◽  
Ovarian Tissue ◽  
Hippo Pathway ◽  
Primordial Follicle ◽  
Akt Pathway ◽  
Primordial Follicles ◽  
Primordial Follicle Activation ◽  
The Hippo Pathway ◽  
Follicle Activation

Abstract STUDY QUESTION What is the role of the Hippo and PI3K/Akt pathway in follicles during ovarian tissue culture in tissue derived from oncological patients and transgender men? SUMMARY ANSWER Results highlight a Hippo pathway driven primordial follicle activation in vitro, predominantly from Day 0 to Day 4. WHAT IS KNOWN ALREADY In-vitro ovarian tissue culture aims at activating and maturing primordial follicles for fertility restoration in patients with a threatened ovarian reserve. Not all patients are eligible for ovarian cortex transplantation and therefore several groups are attempting to culture ovarian tissue in-vitro. Cortex fragmentation disrupts the Hippo pathway, leading to increased expression of downstream growth factors and follicle growth. The PI3K/Akt pathway is considered the intracellular pathway to where different extracellular factors involved in primordial follicle activation in-vivo converge. In order to optimise current ovarian tissue culture models, information on progression of these pathways during tissue culture is mandatory. STUDY DESIGN, SIZE, DURATION The first step of a multistep cortex culture system was performed using 144 ovarian cortex pieces from a total of six patients. Per patient, 24 cortical strips were cultured for 6 days and six pieces per patient were collected for downstream analysis of follicle development and Hippo and PI3K/Akt pathway targets every second day. PARTICIPANTS/MATERIALS, SETTING, METHODS Ovarian tissue was obtained from oncological (N = 3; 28.67 ± 4.51 years) and transgender (N = 3; 23.33 ± 1.53 years) patients. Follicles were analysed using haematoxylin-eosin staining and pathways were studied using immunohistochemistry and precise follicle excision by laser capture micro-dissection for RT-qPCR analysis. MIQE guidelines for RT-qPCR were pursued. Reference gene selection (GAPDH, RPL3A, 18s rRNA) was performed using GeNorm Reference Gene Selection Kit. Statistical analysis was conducted with IBM SPSS Statistics 23 (Poisson regression, negative binomial regression, ANOVA and paired t-test). MAIN RESULTS AND THE ROLE OF CHANCE Immunohistochemical analysis confirmed a Hippo pathway driven primordial follicle activation due to mechanical manipulation of the cortical strips. Ovarian tissue preparation and culture induced the inhibitory phosphorylated Yes-associated protein (pYAP) to disappear in granulosa cells of primordial follicles on Day 2. The stimulatory YAP on the contrary appeared in primordial granulosa cells over increasing culture days. Looking at the YAP target connective tissue growth factor (CTGF), a significantly up-regulated CTGF was noted in primordial follicles when comparing Day 2 and Day 4 (ratio Day 2/4 = 0.082; P < 0.05), clearly showing an effect on the Hippo pathway in primordial follicles during tissue culture. Follicle classification showed a significant drop in estimated primordial follicle counts in the oncological cohort (−78%; P = 0.021) on Day 2 and in the transgender cohort on Day 4 (−634%; P = 0.008). Intermediate follicle counts showed a non-significant increasing trend to during culture and this follicle recruitment and growth resulted in a significant rise in estimated primary follicle counts on Day 6 in oncological patients (170%; P = 0.025) and, although limited in absolute numbers, a significant increase in secondary follicles on Day 4 (367%; P = 0.021) in the transgender cohort. Subsequent antral follicle development could not be observed. LIMITATIONS, REASONS FOR CAUTION A limitation is the small sample size, inherent to this study subject, especially as a large amount of tissue was needed per patient to reduce inter-patient variation in different downstream analysis techniques. A particular and specific weakness of this study is the inability to include an age-matched control group. WIDER IMPLICATIONS OF THE FINDINGS These findings support an adapted tissue preparation for Hippo pathway disruption and a shorter first phase of tissue culture. This work may also have implications for transplantation of cryopreserved tissue as larger strips (and thus slower burnout due to less Hippo pathway disruption) could be a benefit. STUDY FUNDING/COMPETING INTEREST(S) This research was financially supported by the Foundation Against Cancer (Stichting tegen Kanker, TBMT001816N), the Flemish Foundation of Scientific Research (FWO Vlaanderen, FWO G0.065.11N10) and the Gender Identity Research and Education Society (GIRES) foundation. The authors declare no competing interests. TRIAL REGISTRATION NUMBER N/A.

scholarly journals A gatekeeping role of ESR2 to maintain the primordial follicle reserve

2020 ◽  
Author(s):  
V. Praveen Chakravarthi ◽  
Subhra Ghosh ◽  
Katherine F. Roby ◽  
Michael W. Wolfe ◽  
M. A. Karim Rumi
Keyword(s):  
Transcriptional Activation ◽  
Primordial Follicle ◽  
Activation Function ◽  
Fixed Number ◽  
Primordial Follicles ◽  
Selective Agonist ◽  
Primordial Follicle Activation ◽  
Excessive Activation ◽  
Follicle Activation

AbstractOver the entire reproductive lifespan in mammals, a fixed number of primordial follicles serve as the source of mature oocytes. Uncontrolled and excessive activation of primordial follicles can lead to depletion of the ovarian reserve. We observed that disruption of ESR2-signaling results in increased activation of primordial follicles in Esr2-null (Esr2-/-) rats. However, follicle assembly was unaffected, and the total number of follicles remained comparable between neonatal wildtype and Esr2-/- ovaries. While the activated follicle counts were increased in Esr2-/- ovary, the number of primordial follicles were markedly decreased. Excessive recruitment of primordial follicles led to premature ovarian senescence in Esr2-/- rats and was associated with reduced levels of serum AMH and estradiol. Disruption of ESR2-signaling through administration of a selective antagonist (PHTPP) increased the number of activated follicles in wildtype rats, whereas a selective agonist (DPN) decreased follicle activation. In contrast, primordial follicle activation was not increased in the absence of ESR1 indicating that the regulation of primordial follicle activation is ESR2-specific. Follicle activation was also increased in Esr2-mutants lacking the DNA-binding domain, suggesting a role for the canonical transcriptional activation function. Both primordial and activated follicles express ESR2 suggesting a direct regulatory role for ESR2 within these follicles. We also detected that loss of ESR2 augmented the activation of AKT, ERK and mTOR pathways. Our results indicate that the lack of ESR2 upregulated both granulosa and oocyte factors, which can facilitate AKT and mTOR activation in Esr2-/- ovaries leading to increased activation of primordial follicles.

scholarly journals Specificity of the requirement for Foxo3 in primordial follicle activation

Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 855-863 ◽  
Author(s):  
George B John ◽  
Lane J Shirley ◽  
Teresa D Gallardo ◽  
Diego H Castrillon
Keyword(s):  
Germ Line ◽  
Primordial Follicle ◽  
Forkhead Transcription Factor ◽  
Primordial Follicles ◽  
Mouse Mutants ◽  
Physiological Processes ◽  
Primordial Follicle Activation ◽  
Mammalian Female ◽  
Structure Assembly ◽  
Follicle Activation

Primordial follicles are long-lived structures assembled early in life. The mechanisms that control the balance between the conservation and the activation of primordial follicles are critically important for fertility and dictate the onset of menopause. The forkhead transcription factor Foxo3 serves an essential role in these processes by suppressing the growth of primordial follicles, thereby preserving them until later in life. While other factors regulating primordial follicle growth have been described, most serve multiple functions at several stages of female germ cell or follicle development, and corresponding mouse mutants exhibit pleiotropic phenotypes with disruption of multiple stages of follicle assembly, development, or survival. To investigate the possibility that Foxo3 also functions in other aspects of ovarian development beyond its known role in primordial follicle activation (PFA), we performed detailed analyses of mouse ovaries including electron microscopy to study primordial follicle structure, assembly, and early growth. These analyses revealed that the timing of primordial follicle assembly, early oocyte survival, and the expression of early germ line markers were unaffected in early Foxo3 ovaries. Taken together, these studies demonstrate that the phenotype associated with Foxo3 deficiency is remarkably specific for PFA and further support the placement of Foxo3 in a unique phenotypic class among mammalian female sterile mutants. Lastly, we discuss the implications of the specificity of this mutant phenotype with regard to the hypothesis that oocyte regeneration may occur in adults and serves as a means to replenish oocytes lost via natural physiological processes.

Effects of jacalin and follicle-stimulating hormone on in vitro goat primordial follicle activation, survival and gene expression

Zygote ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 537-549 ◽  
Author(s):  
Regislane P. Ribeiro ◽  
Antonia M.L.R. Portela ◽  
Anderson W.B. Silva ◽  
José J.N. Costa ◽  
José R.S. Passos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ovarian Tissue ◽  
Follicle Stimulating Hormone ◽  
Primordial Follicle ◽  
Nuclear Antigen ◽  
Primordial Follicles ◽  
Primordial Follicle Activation ◽  
Follicle Activation ◽  
Stimulating Hormone

SummaryThis study aims to investigate the effects of jacalin and follicle-stimulating hormone (FSH) on activation and survival of goat primordial follicles, as well as on gene expression in cultured ovarian tissue. Ovarian fragments were cultured for 6 days in minimum essential medium (MEM) supplemented with jacalin (10, 25, 50 or 100 μg/ml – Experiment 1) or in MEM supplemented with jacalin (50 μg/ml), FSH (50 ng/ml) or both (Experiment 2). Non-cultured and cultured tissues were processed for histological and ultrastructural analysis. Cultured tissues from Experiment 2 were also stored to evaluate the expression of BMP-15, KL (Kit ligand), c-kit, GDF-9 and proliferating cell nuclear antigen (PCNA) by real-time polymerase chain reaction (PCR). The results of Experiment 1 showed that, compared with tissue that was cultured in control medium, the presence of 50 μg/ml of jacalin increased both the percentages of developing follicles and viability. In Experiment 2, after 6 days, higher percentages of normal follicles were observed in tissue cultured in presence of FSH, jacalin or both, but no synergistic interaction between FSH and jacalin was observed. These substances had no significant effect on the levels of mRNA for BMP-15 and KL, but FSH increased significantly the levels of mRNA for PCNA and c-kit. On the other hand, jacalin reduced the levels of mRNA for GDF-9. In conclusion, jacalin and FSH are able to improve primordial follicle activation and survival after 6 days of culture. Furthermore, presence of FSH increases the expression of mRNA for PCNA and c-kit, but jacalin resulted in lower GDF-9 mRNA expression.

scholarly journals Phosphodiesterases in the rat ovary: effect of cAMP in primordial follicles

Reproduction ◽  
2015 ◽  
Vol 150 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Tonny Studsgaard Petersen ◽  
Martin Stahlhut ◽  
Claus Yding Andersen
Keyword(s):  
Primordial Follicle ◽  
Neonatal Rat ◽  
Intracellular Camp ◽  
Corpora Lutea ◽  
Dependent Manner ◽  
Primordial Follicles ◽  
Primordial Follicle Activation ◽  
Rat Ovary ◽  
Follicle Differentiation ◽  
Follicle Activation

Phosphodiesterases (PDEs) are important regulators of the intracellular cAMP concentration, which is a central second messenger that affects a multitude of intracellular functions. In the ovaries, cAMP exerts diverse functions, including regulation of ovulation and it has been suggested that augmented cAMP levels stimulate primordial follicle growth. The present study examined the gene expression, enzyme activity and immunolocalization of the different cAMP hydrolysing PDEs families in the rat ovary. Further, the effect of PDE4 inhibition on primordial follicle activation in cultured neonatal rat ovaries was also evaluated. We found varied expression of all eight families in the ovary with Pde7b and Pde8a having the highest expression each accounting for more than 20% of the total PDE mRNA. PDE4 accounted for 15–26% of the total PDE activity. Immunoreactive PDE11A was found in the oocytes and PDE2A in the corpora lutea. Incubating neonatal rat ovaries with PDE4 inhibitors did not increase primordial follicle activation or change the expression of the developing follicle markers Gdf9, Amh, Inha, the proliferation marker Mki67 or the primordial follicle marker Tmeff2. In addition, the cAMP analogue 8-bromo-cAMP did not increase AKT1 or FOXO3A phosphorylation associated with follicle activation or increase the expression of Kitlg known to be associated with follicle differentiation but did increase the Tmeff2, Mki67 and Inha expression in a dose-dependent manner. In conclusion, this study shows that both Pde7b and Pde8a are highly expressed in the rodent ovary and that PDE4 inhibition does not cause an increase in primordial follicle activation.

scholarly journals Transcriptomic profiling of neonatal mouse granulosa cells reveals new insights into primordial follicle activation

2021 ◽  
Author(s):  
Emmalee A Ford ◽  
Emily R Frost ◽  
Emma L Beckett ◽  
Shaun D Roman ◽  
Eileen A McLaughlin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Granulosa Cells ◽  
Expression Profiles ◽  
Primordial Follicle ◽  
Differentially Expressed ◽  
Primary Follicle ◽  
Primordial Follicles ◽  
Time Points ◽  
Primordial Follicle Activation ◽  
Follicle Activation

Abstract The dormant population of ovarian primordial follicles is determined at birth and serves as the reservoir for future female fertility. Yet our understanding of the molecular, biochemical, and cellular processes underpinning primordial follicle activation remains limited. The survival of primordial follicles relies on the correct complement and morphology of granulosa cells, which provide signalling factors essential for oocyte and follicular survival. To investigate the contribution of granulosa cells in the primordial-to-primary follicle transition, gene expression profiles of granulosa cells undergoing early differentiation were assessed in a murine model. Ovaries from C57Bl/6 mice were enzymatically dissociated at time-points spanning the initial wave of primordial follicle activation. Post-natal day (PND) 1 ovaries yielded primordial granulosa cells, and PND4 ovaries yielded a mixed population of primordial and primary granulosa cells. The comparative transcriptome of granulosa cells at these time-points was generated via Illumina NextSeq 500 system which identified 131 significantly differentially expressed transcripts. The differential expression of eight of the transcripts was confirmed by RT-qPCR Following biological network mapping via Ingenuity Pathway Analysis, the functional expression of the protein products of three of the differentially expressed genes, namely FRZB, POD1 and ZFX, was investigated with in-situ immunolocalisation in PND4 mouse ovaries was investigated. Finally, evidence was provided that Wnt pathway antagonist, secreted frizzled-related protein 3 (FRZB), interacts with a suppressor of primordial follicle activation WNT3A and may be involved in promoting primordial follicle activation. This study highlights the dynamic changes in gene expression of granulosa cells during primordial follicle activation and provides evidence for a renewed focus into the Wnt signalling pathway’s role in primordial follicle activation.

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