scholarly journals Heparan Sulfate Proteoglycans Regulate Responses to Oocyte Paracrine Signals in Ovarian Follicle Morphogenesis

Endocrinology ◽  
2012 ◽  
Vol 153 (9) ◽  
pp. 4544-4555 ◽  
Author(s):  
Laura N. Watson ◽  
David G. Mottershead ◽  
Kylie R. Dunning ◽  
Rebecca L. Robker ◽  
Robert B. Gilchrist ◽  
...  

In the ovarian follicle, oocyte-secreted factors induce cumulus-specific genes and repress mural granulosa cell specific genes to establish these functionally distinct cell lineages. The mechanism establishing this precise morphogenic pattern of oocyte signaling within the follicle is unknown. The present study investigated a role for heparan sulphate proteoglycans (HSPG) as coreceptors mediating oocyte secreted factor signaling. In vitro maturation of cumulus oocyte complexes in the presence of exogenous heparin, which antagonizes HSPG signaling, prevented cumulus expansion and blocked the induction of cumulus-specific matrix genes, Has2 and Tnfaip6, whereas conversely, the mural granulosa-specific genes, Lhcgr and Cyp11a1, were strongly up-regulated. Heparin also blocked phosphorylation of SMAD2. Exogenous growth differentiation factor (GDF)-9 reversed these heparin effects; furthermore, GDF9 strongly bound to heparin sepharose. These observations indicate that heparin binds endogenous GDF9 and disrupts interaction with heparan sulphate proteoglycan coreceptor(s), important for GDF9 signaling. The expression of candidate HSPG coreceptors, Syndecan 1–4, Glypican 1–6, and Betaglycan, was examined. An ovulatory dose of human chorionic gonadotropin down-regulated Betaglycan in cumulus cells, and this regulation required GDF9 activity; conversely, Betaglycan was significantly increased in luteinizing mural granulosa cells. Human chorionic gonadotropin caused very strong induction of Syndecan 1 and Syndecan 4 in mural granulosa as well as cumulus cells. Glypican 1 was selectively induced in cumulus cells, and this expression appeared dependent on GDF9 action. These data suggest that HSPG play an essential role in GDF9 signaling and are involved in the patterning of oocyte signaling and cumulus cell function in the periovulatory follicle.

2015 ◽  
Vol 27 (2) ◽  
pp. 407 ◽  
Author(s):  
Karen L. Kind ◽  
Kimberley K. Y. Tam ◽  
Kelly M. Banwell ◽  
Ashley D. Gauld ◽  
Darryl L. Russell ◽  
...  

Oxygen is an important component of the environment of the cumulus–oocyte complex (COC), both in vivo within the ovarian follicle and during in vitro oocyte maturation (IVM). Cumulus cells have a key role in supporting oocyte development, and cumulus cell function and gene expression are known to be altered when the environment of the COC is perturbed. Oxygen-regulated gene expression is mediated through the actions of the transcription factors, the hypoxia-inducible factors (HIFs). In the present study, the effect of oxygen on cumulus cell gene expression was examined following in vitro maturation of the murine COC at 2%, 5% or 20% oxygen. Increased expression of HIF-responsive genes, including glucose transporter-1, lactate dehydrogenase A and BCL2/adenovirus E1B interacting protein 3, was observed in cumulus cells matured at 2% or 5%, compared with 20% oxygen. Stabilisation of HIF1α protein in cumulus cells exposed to low oxygen was confirmed by western blot and HIF-mediated transcriptional activity was demonstrated using a transgenic mouse expressing green fluorescent protein under the control of a promoter containing hypoxia response elements. These results indicate that oxygen concentration influences cumulus cell gene expression and support a role for HIF1α in mediating the cumulus cell response to varying oxygen.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam J. Ziecik ◽  
Jan Klos ◽  
Katarzyna Gromadzka-Hliwa ◽  
Mariola A. Dietrich ◽  
Mariola Slowinska ◽  
...  

AbstractDifferent strategies are used to meet optimal reproductive performance or manage reproductive health. Although exogenous human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH) agonists (A) are commonly used to trigger ovulation in estrous cycle synchronization, little is known about their effect on the ovarian follicle. Here, we explored whether hCG- and GnRH-A-induced native luteinizing hormone (LH) can affect the endocrine and molecular milieus of ovarian preovulatory follicles in pigs at different stages of sexual development. We collected ovaries 30 h after hCG/GnRH-A administration from altrenogest and pregnant mare serum gonadotropin (eCG)-primed prepubertal and sexually mature gilts. Several endocrine and molecular alternations were indicated, including broad hormonal trigger-induced changes in follicular fluid steroid hormones and prostaglandin levels. However, sexual maturity affected only estradiol levels. Trigger- and/or maturity-dependent changes in the abundance of hormone receptors (FSHR and LHCGR) and proteins associated with lipid metabolism and steroidogenesis (e.g., STAR, HSD3B1, and CYP11A1), prostaglandin synthesis (PTGS2 and PTGFS), extracellular matrix remodeling (MMP1 and TIMP1), protein folding (HSPs), molecular transport (TF), and cell function and survival (e.g., VIM) were observed. These data revealed different endocrine properties of exogenous and endogenous gonadotropins, with a potent progestational/androgenic role of hCG and estrogenic/pro-developmental function of LH.


2015 ◽  
Vol 27 (1) ◽  
pp. 133
Author(s):  
K. Uhde ◽  
L. T. A. van Tol ◽  
T. A. E. Stout ◽  
B. A. J. Roelen

A mammalian oocyte within an ovarian follicle is surrounded by cumulus cells, together this structure is known as the cumulus-oocyte complex (COC). Cumulus cells are important for the development of the oocyte, they support the maturation process of the oocyte within the ovary and aid in sperm recognition. Because it is known that a Dicer knockout leads to infertility, microRNAs (miRNA) are focused to have an important role in oocyte development. MiRNAs are small noncoding RNA sequences that act as transcriptional regulators. Little is known about the expression of miRNA in cumulus cells or how cumulus-derived miRNA may regulate or be used to indicate the developmental competence of the maturing oocyte. Our aim was to investigate miRNA expression in oocytes and to identify and establish how specific miRNA influence the acquisition of developmental competence by bovine oocytes. Normalization of qPCR data requires stable reference genes. To this end, we tested the expression of various miRNA with respect to their ability to be used as reference miRNA for bovine cumulus cells; these included miR-103, miR-93, miR-26, let-7a, miR-191, and the small noncoding nuclear RNA U6. Cumulus-oocyte complexes were recovered from the ovaries of slaughtered cows and matured in vitro. Small samples of cumulus cells were collected from these COC before and after maturation. From the cumulus cell groups recovered at different stages, small RNA were extracted and cDNA was synthesised, followed by qRT-PCR. To identify the optimal combination of reference genes, the geNorm algorithm was used. MiR-26a and let-7a were identified as the most stably expressed miRNAs, whereas U6 showed the most variable expression levels. Future investigations are planned to identify miRNA in cumulus cells that can be used as markers for oocyte developmental competence. Using a single oocyte-embryo culture system will enable us to retrospectively relate cumulus miRNA expression to the developmental capacity of the oocyte.This work was supported by EU FP7 EpiHealthNet (N°317146).


Author(s):  
Aslihan Turhan ◽  
Miguel Tavares Pereira ◽  
Gerhard Schuler ◽  
Ulrich Bleul ◽  
Mariusz P Kowalewski

Abstract Various metabolic and hormonal factors expressed in cumulus cells are positively correlated with the in vitro maturation (IVM) of oocytes. However, the role of hypoxia sensing both during maturation of cumulus–oocyte complexes (COCs) as well as during the resumption of meiosis remains uncertain. HIF1alpha plays major roles in cellular responses to hypoxia, and here we investigated its role during bovine COC maturation by assessing the expression of related genes in cumulus cells. COCs were divided into the following groups: immature (control), in vitro matured (IVM/control), or matured in the presence of a blocker of HIF1alpha activity (echinomycin, IVM/E). We found an inhibition of cumulus cell expansion in IVM/E, compared with the IVM/control. Transcript levels of several factors (n = 13) were assessed in cumulus cells. Decreased expression of HAS2, TNFAIP6, TMSB4, TMSB10, GATM, GLUT1, CX43, COX2, PTGES, and STAR was found in IVM/E (P < 0.05). Additionally, decreased protein levels were detected for STAR, HAS2, and PCNA (P < 0.05), while activated-Caspase 3 remained unaffected in IVM/E. Progesterone output decreased in IVM/E. The application of PX-478, another blocker of HIF1alpha expression, yielded identical results. Negative effects of HIF1alpha suppression were further observed in the significantly decreased oocyte maturation and blastocyst rates from COCs matured with echinomycin (P < 0.05) or PX-478 (P < 0.05). These results support the importance of HIF1alpha for COC maturation and subsequent embryo development. HIF1alpha is a multidirectional factor controlling intercellular communication within COCs, steroidogenic activity, and oocyte development rates, and exerting effects on blastocyst rates.


Endocrinology ◽  
2012 ◽  
Vol 153 (8) ◽  
pp. 3949-3959 ◽  
Author(s):  
Ikko Kawashima ◽  
Zhilin Liu ◽  
Lisa K. Mullany ◽  
Toshihiro Mihara ◽  
Joanne S. Richards ◽  
...  

Cumulus cell-oocyte complex (COC) expansion is obligatory for LH-induced ovulation and is initiated by LH induction of the epidermal growth factor (EGF)-like factors that mediate the synthesis of the hyaluronan-rich matrix and hyaluronan-stabilizing factors. COC expansion also involves the movement of cumulus cells within the matrix by mechanisms that have not been characterized. We document herein that two proteases, calpain 2 and to a lesser extent calpain 1, are expressed in cumulus cells and that the proteolytic activity of these enzymes is rapidly and significantly increased in COC isolated from human chorionic gonadotropin-induced ovulatory follicles in vivo. Stimulation of calpain activity was associated with proteolytic degradation of paxillin and talin (two components of focal adhesion complexes), cell detachment, and the formation of cell surface bleb-like protrusions. Injection of a calpain inhibitor in vivo reduced 1) human chorionic gonadotropin-stimulated calpain enzyme activity, 2) cell detachment, 3) membrane protrusion formation, and 4) COC expansion by mechanisms that did not alter Has2 expression. During EGF-like factor induction of COC expansion in culture, calpain activity was increased by ERK1/2 and intracellular Ca2+ signaling pathways. Inhibition of calpain activity in cultured COC blocked cumulus cell detachment, protrusion formation, and the vigorous movement of cumulus cells. As a consequence, COC expansion was impaired. Collectively, these results show that two highly coordinated processes control COC expansion. One process involves the synthesis of the hyaluronan matrix, and the other mediates cumulus cell detachment and movement. The latter are controlled by calpain activation downstream of the EGF receptor activation of the Ca2+ pathway and ERK1/2 pathways.


Endocrinology ◽  
2009 ◽  
Vol 150 (7) ◽  
pp. 3360-3368 ◽  
Author(s):  
Zhilin Liu ◽  
Daniel G. de Matos ◽  
Heng-Yu Fan ◽  
Masayuki Shimada ◽  
Stephen Palmer ◽  
...  

Ovulation has long been regarded as a process resembling an inflammatory response. Recent studies indicate that genes associated with innate immune responses were also expressed during the ovulation process. Because the innate immune genes are induced in cumulus cell oocyte complexes (COCs) later than the inflammation-associated genes, we hypothesize that COC expansion is dependent on specific sequential changes in cumulus cells. Because IL-6 is a potent mediator of immune responses, we sought to determine what factors regulate the induction of Il6 mRNA in COCs and what impact IL-6 alone would have on COC expansion. We found that the levels of Il6 mRNA increased dramatically during COC expansion, both in vivo and in vitro. Moreover, IL-6, together with its soluble receptor (IL-6SR), could bypass the need for either amphiregulin and/or prostaglandin E2 to induce the expansion of COCs. This ability of IL-6/IL-6SR to induce COC expansion was blocked by the inhibitors to p38MAPK, MAPK kinase 1/2, and Janus kinase. More importantly, when COCs were in vitro maturated in the presence of IL-6, they had a significantly higher embryo transfer rate than the ones without IL-6 and comparable with in vivo matured oocytes. IL-6/IL-6SR activated multiple signaling pathways (Janus kinase/signal transducer and activator of transcription, ERK1/2, p38MAPK, and AKT) and progressively induced genes known to impact COC expansion, genes related to inflammation and immune responses, and some transcription factors. Collectively, these data indicate that IL-6 alone can act as a potent autocrine regulator of ovarian cumulus cell function, COC expansion, and oocyte competence.


2013 ◽  
Vol 25 (2) ◽  
pp. 426 ◽  
Author(s):  
Karen L. Kind ◽  
Kelly M. Banwell ◽  
Kathryn M. Gebhardt ◽  
Anne Macpherson ◽  
Ashley Gauld ◽  
...  

The IVM of mammalian cumulus–oocyte complexes (COCs) yields reduced oocyte developmental competence compared with oocytes matured in vivo. Altered cumulus cell function during IVM is implicated as one cause for this difference. We have conducted a microarray analysis of cumulus cell mRNA following IVM or in vivo maturation (IVV). Mouse COCs were sourced from ovaries of 21-day-old CBAB6F1 mice 46 h after equine chorionic gonadotrophin (5 IU, i.p.) or from oviducts following treatment with 5 IU eCG (61 h) and 5 IU human chorionic gonadotrophin (13 h). IVM was performed in α-Minimal Essential Medium with 50 mIU FSH for 17 h. Three independent RNA samples were assessed using the Affymetrix Gene Chip Mouse Genome 430 2.0 array (Affymetrix, Santa Clara, CA, USA). In total, 1593 genes were differentially expressed, with 811 genes upregulated and 782 genes downregulated in IVM compared with IVV cumulus cells; selected genes were validated by real-time reverse transcription–polymerase chain reaction (RT-PCR). Surprisingly, haemoglobin α (Hba-a1) was highly expressed in IVV relative to IVM cumulus cells, which was verified by both RT-PCR and western blot analysis. Because haemoglobin regulates O2 and/or nitric oxide availability, we postulate that it may contribute to regulation of these gases during the ovulatory period in vivo. These data will provide a useful resource to determine differences in cumulus cell function that are possibly linked to oocyte competence.


Endocrinology ◽  
2005 ◽  
Vol 146 (6) ◽  
pp. 2817-2826 ◽  
Author(s):  
Judith M. A. Emmen ◽  
John F. Couse ◽  
Susan A. Elmore ◽  
Mariana M. Yates ◽  
Grace E. Kissling ◽  
...  

Abstract Both estrogen receptor (ER) α and β are expressed within the ovary and lack of either of these receptors affects ovarian function. In this study, the role of ERα and ERβ in folliculogenesis and ovulation was further analyzed. Evaluation of ovarian follicle populations in wild-type and ERβ knockout (βERKO) ovaries revealed reduced late antral growth and ovulatory capacity of βERKO follicles, indicated by reduced numbers of large antral follicles and corpora lutea and increased atresia of large antral follicles. An in vitro culture system was used to study growth, rupture, and luteinization of wild-type, ERα knockout (αERKO) and βERKO ovarian follicles. αERKO follicles exhibited wild-type-like growth and ovulation rates but an increased capacity to synthesize estradiol. In contrast, βERKO follicles showed a significant lack of progression from early antral to large antral stage, decreased estradiol production, and reduced ovulation. Expression patterns of several genes involved in follicle maturation and ovulation were analyzed in follicles grown in vitro. Ar, Pgr, and Has2 mRNA expression levels were the same among the three genotypes. However, βERKO follicles showed reduced expression of Cyp19 mRNA during follicle maturation and reduced Lhcgr and Ptgs2 mRNA expression after human chorionic gonadotropin stimulus. Luteinization occurs normally in αERKO and βERKO follicles, shown by increased progesterone secretion and increased cdkn1b mRNA expression after human chorionic gonadotropin. Collectively, these data indicate that ERβ, but not ERα, plays a direct role in folliculogenesis. ERβ appears to facilitate follicle maturation from the early antral to the preovulatory stage.


Sign in / Sign up

Export Citation Format

Share Document