scholarly journals Apelin (APLN) regulates progesterone secretion and oocyte maturation in bovine ovarian cells

Reproduction ◽  
2017 ◽  
Vol 153 (5) ◽  
pp. 589-603 ◽  
Author(s):  
J Roche ◽  
C Ramé ◽  
M Reverchon ◽  
N Mellouk ◽  
A Rak ◽  
...  

APLN and its G-protein coupled receptor APLNR are expressed in the bovine ovary. However their role in granulosa cells and oocytes is unknown. Here, we studied their expression in bovine ovarian cells and investigated their regulation in cultured luteinizing granulosa cells in response to IGF1 and FSH. We determined the effect and the molecular mechanism of APLN (isoforms 17 and 13) on bovine granulosa cell progesterone secretion and on oocyte maturation. By RT-qPCR and immunoblot, we showed that the expression of both APLN and APLNR in granulosa and oocytes significantly increased with ovarian follicles size whereas it was similar in theca interstitial cells.In vitro, in unstimulated luteinizing bovine granulosa cells and in response to IGF1 (10−8 M) but not to FSH (10−8 M), we observed that APLN (-17 and -13) (10−9 M) increased progesterone production; this was abolished in response to the APLNR antagonist ML221. These latter effects were dependent on the MAPK ERK1/2 kinase. Furthermore, we showed that APLN (-17 and -13) (10−9 M) increased cell proliferation through AKT signaling. Conversely, the addition of APLN-13 and APLN-17 toin vitromaturation medium containing IGF1 (10−8 M) but not FSH (10−8 M) arrested most oocytes at the germinal vesicle stage, which was associated with a decrease in progesterone secretion, an inhibition in MAPK ERK1/2 phosphorylation and an increase in PRKA phosphorylation in oocytes. Thus, APLN can increase progesterone secretion and cell proliferation in bovine luteinizing granulosa cellsin vitro, while it blocks meiotic progression at the germinal vesicle stage during bovine oocytein vitromaturation.

1994 ◽  
Vol 142 (3) ◽  
pp. 497-510 ◽  
Author(s):  
D Monniaux ◽  
C Pisselet ◽  
J Fontaine

Abstract Granulosa cells of ovarian follicles both proliferate and undergo differentiation. In vivo, an inverse relationship between proliferation and steroidogenesis is observed. However, both processes can be enhanced by insulin-like growth factor-I (IGF-I) in vitro. Studies were undertaken in the ewe to understand the mechanisms controlling the balance between proliferation and differentiation in cultured granulosa cells from antral follicles better. For this purpose, granulosa cells from ovine small follicles (1–3 mm in diameter) and large follicles (5–7 mm in diameter) were compared for progesterone secretion, cytochrome P450 side-chain cleavage (P450scc) expression and their proportions of non-proliferating (G0) cells, in response to IGF-I and FSH stimulation in vitro. IGF-I mainly enhanced the proliferation of granulosa cells from small follicles but it strongly increased progesterone secretion and P450scc expression in granulosa cells from large follicles, in synergy with FSH. Blocking granulosa cell proliferation by the administration of colcemid or aphidicolin had no effect or a weak stimulating effect on progesterone secretion. At the beginning of the culture period, the proportion of non-proliferating cells, estimated by continuous [3H]thymidine labelling experiments, was clearly higher in large than in small follicles (91% vs 30%, P<0·001). For both cell types, treatment with IGF-I in vitro reduced the proportion of non-proliferating cells at 72 h of culture (40% vs 70% respectively in IGF-I-stimulated and unstimulated cells from large follicles, P<0·001, and 17% vs 30% respectively in IGF-I-stimulated and unstimulated cells from small follicles, P<0·001). Treatment with FSH had no effect on the proportion of non-proliferating cells. As revealed by immunohistochemistry experiments, IGF-I, in synergy with FSH, clearly increased the percentage of cells expressing P450scc enzyme and the intensity of staining in granulosa cells from large follicles. Unexpectedly, heavily stained cells in mitosis were observed in IGF-I-stimulated cells from large follicles after 96 h of culture, suggesting that dividing cells might also produce progesterone. Overall, these results support the hypothesis that the growth-promoting and the cytodifferentiative effects of IGF-I are clearly distinct. Moreover, they suggest that uncoupling between proliferation and steroidogenesis may occur in cultured ovine granulosa cells. The loss of proliferative activity accompanying terminal follicular growth in vivo could be reversed in vitro. During terminal follicular growth in vivo, the existence of an active mechanism inhibiting granulosa cell proliferation, and unrelated to terminal differentiation, is therefore strongly suspected. Journal of Endocrinology (1994) 142, 497–510


Author(s):  
Letícia Ferrari Crocomo ◽  
Federica Ariu ◽  
Luisa Bogliolo ◽  
Daniela Bebbere ◽  
Sergio Ledda ◽  
...  

Abstract: The objective of this work was to evaluate the efficiency of roscovitine on reversibly inhibiting oocytes from prepubertal sheep at the germinal vesicle (GV) stage, and to investigate the kinetics of meiosis progression after inhibitor removal. Cumulus-oocyte complexes, recovered from Sarda breed lambs aged 30-40 days, were cultured for 6 hours in a maturation medium (control) containing 75 μmol L-1 roscovitine (Rosco) at 38.5°C and 5% CO2. Then, the complexes were subjected to in vitro maturation (IVM) for 18 or 23 hours, in an inhibitor-free medium supplemented with gonadotropins. The evaluation of nuclear configuration by Hoescht staining, under a fluorescence-inverted microscope, showed that 88.7% of the lamb oocytes treated with roscovitine remained at the GV stage, as observed for the immature ones (97.3%) stained after collection. The inhibitory action was reversible; however, the proportion of oocytes (83.3%) at the metaphase-II stage, after 23 hours of IVM, was significantly higher than that observed after 18 hours (29.5%), in which meiosis was still in progression with 34.2% oocytes at metaphase-I, 11.6% oocytes at anaphase-I, and 18.5% oocytes at telophase-I. Roscovitine is efficient to arrest the nuclear maturation in oocytes from prepubertal sheep; however, despite the reversibility, meiosis progression is delayed, requiring more time to be completed.


Author(s):  
Er-Meng Gao ◽  
Bongkoch Turathum ◽  
Ling Wang ◽  
Di Zhang ◽  
Yu-Bing Liu ◽  
...  

AbstractThis study evaluated the differences in metabolites between cumulus cells (CCs) and mural granulosa cells (MGCs) from human preovulatory follicles to understand the mechanism of oocyte maturation involving CCs and MGCs. CCs and MGCs were collected from women who were undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. The differences in morphology were determined by immunofluorescence. The metabolomics of CCs and MGCs was measured by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) followed by quantitative polymerase chain reaction (qPCR) and western blot analysis to further confirm the genes and proteins involved in oocyte maturation. CCs and MGCs were cultured for 48 h in vitro, and the medium was collected for detection of hormone levels. There were minor morphological differences between CCs and MGCs. LC-MS/MS analysis showed that there were differences in 101 metabolites between CCs and MGCs: 7 metabolites were upregulated in CCs, and 94 metabolites were upregulated in MGCs. The metabolites related to cholesterol transport and estradiol production were enriched in CCs, while metabolites related to antiapoptosis were enriched in MGCs. The expression of genes and proteins involved in cholesterol transport (ABCA1, LDLR, and SCARB1) and estradiol production (SULT2B1 and CYP19A1) was significantly higher in CCs, and the expression of genes and proteins involved in antiapoptosis (CRLS1, LPCAT3, and PLA2G4A) was significantly higher in MGCs. The level of estrogen in CCs was significantly higher than that in MGCs, while the progesterone level showed no significant differences. There are differences between the metabolomes of CCs and MGCs. These differences may be involved in the regulation of oocyte maturation.


Author(s):  
Christina I. Messini ◽  
Anna Vasilaki ◽  
Evangelia Korona ◽  
George Anifandis ◽  
Eleni Katsiani ◽  
...  

Author(s):  
Sarah Beschta ◽  
Katja Eubler ◽  
Nancy Bohne ◽  
Ignasi Forne ◽  
Dieter Berg ◽  
...  

AbstractHuman primary granulosa cells (GCs) derived from women undergoing oocyte retrieval can be cultured and used as a cellular model for the study of human ovarian function. In vitro, they change rapidly, initially resembling cells of the preovulatory follicle and then cells of the corpus luteum. They are derived from individual patients, whose different medical history, lifestyle and age lead to heterogeneity. Thus, cells can rarely be ideally matched for cellular experiments or, if available, only in small quantities. We reasoned that cryopreservation of human GCs may be helpful to improve this situation. Previous studies indicated the feasibility of such an approach, but low survival of human GCs was reported, and effects on human GC functionality were only partially evaluated. We tested a slow freezing protocol (employing FCS and DMSO) for human GCs upon isolation from follicular fluid. We compared cryopreserved and subsequently thawed cells with fresh, non-cryopreserved cells from the same patients. About 80% of human GCs survived freezing/thawing. No differences were found in cell morphology, survival rate in culture, or transcript levels of mitochondrial (COX4, OPA1, TOMM20), steroidogenic (CYP11A1, CYP19A1) or cell–cell contact genes (GJA1) between the two groups in cells cultured for 1–5 days. A proteomic analysis revealed no statistically significant change in the abundance of a total of 5962 proteins. The two groups produced comparable basal levels of progesterone and responded similarly to hCG with elevation of progesterone. Taken together, our results show this to be a rapid and readily available method for the cryopreservation of human GCs. We anticipate that it will allow future large-scale experiments and may thereby improve cellular studies with human ovarian cells.


Author(s):  
Mohamed Omar Taqi ◽  
Mohammed Saeed-Zidane ◽  
Samuel Gebremedhn ◽  
Dessie Salilew-Wondim ◽  
Ernst Tholen ◽  
...  

AbstractTranscription factors (TFs) are known to be involved in regulating the expression of several classes of genes during folliculogenesis. However, the regulatory role of TFs during oxidative stress (OS) is not fully understood. The current study was aimed to investigate the regulation of the TFs in bovine granulosa cells (bGCs) during exposure to OS induced by H2O2 in vitro. For this, bGCs derived from ovarian follicles were cultured in vitro till their confluency and then treated with H2O2 for 40 min. Twenty-four hours later, cells were subjected to various phenotypic and gene expression analyses for genes related to TFs, endoplasmic reticulum stress, apoptosis, cell proliferation, and differentiation markers. The bGCs exhibited higher reactive oxygen species accumulation, DNA fragmentation, and endoplasmic reticulum stress accompanied by reduction of mitochondrial activity after exposure to OS. In addition, higher lipid accumulation and lower cell proliferation were noticed in H2O2-challenged cells. The mRNA level of TFs including NRF2, E2F1, KLF6, KLF9, FOS, SREBF1, SREBF2, and NOTCH1 was increased in H2O2-treated cells compared with non-treated controls. However, the expression level of KLF4 and its downstream gene, CCNB1, were downregulated in the H2O2-challenged group. Moreover, targeted inhibition of NRF2 using small interference RNA resulted in reduced expression of KLF9, FOS, SREBF2, and NOTCH1 genes, while the expression of KLF4 was upregulated. Taken together, bovine granulosa cells exposed to OS exhibited differential expression of various transcription factors, which are mediated by the NRF2 signaling pathway.


1992 ◽  
Vol 12 (7) ◽  
pp. 3192-3203 ◽  
Author(s):  
K M Pickham ◽  
A N Meyer ◽  
J Li ◽  
D J Donoghue

The p34cdc2 protein kinase is a component of maturation-promoting factor, the master regulator of the cell cycle in all eukaryotes. The activity of p34cdc2 is itself tightly regulated by phosphorylation and dephosphorylation. Predicted regulatory phosphorylation sites of Xenopus p34cdc2 were mutated in vitro, and in vitro-transcribed RNAs were injected into Xenopus oocytes. The cdc2 single mutants Thr-14----Ala and Tyr-15----Phe did not induce germinal vesicle breakdown (BVBD) upon microinjection into oocytes. In contrast, the cdc2 double mutant Ala-14/Phe-15 did induce GVBD. Both the Ala-14 and Ala-14/Phe-15p34cdc2 mutants were shown to coimmunoprecipitate cyclin B1 and to phosphorylate histone H1 in immune complex kinase assays. Microinjection of antisense oligonucleotides to c-mosXe was used to demonstrate the role of mos protein synthesis in the induction of GVBD by the Ala-14/Phe-15 cdc2 mutant. Thr-161 was also mutated. p34cdc2 single mutants Ala-161 and Glu-161 and triple mutants Ala-14/Phe-15/Ala-161 and Ala-14/Phe-15/Glu-161 failed to induce GVBD in oocytes and showed a decreased binding to cyclin B1 in coimmunoprecipitations. Each of the cdc2 mutants was also assayed by coinjection with cyclin B1 or c-mosXe RNA into oocytes. Several of the cdc2 mutants were found to affect the kinetics of cyclin B1 and/or mos-induced GVBD upon coinjection, although none affected the rate of progesterone-induced maturation. We demonstrate here the significance of Thr-14, Tyr-15, and Thr-161 of p34cdc2 in Xenopus oocyte maturation. In addition, these results suggest a regulatory role for mosXe in induction of oocyte maturation by the cdc2 mutant Ala-14/Phe-15.


2013 ◽  
Vol 61 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Anna Nynca ◽  
Dominika Słonina ◽  
Olga Jablońska ◽  
Barbara Kamińska ◽  
Renata Ciereszko

Daidzein, a phytoestrogen present in soybean products used in swine feed, has been demonstrated to affect both reproductive and endocrine functions. The aims of this study were to examine the in vitro effects of daidzein on (1) progesterone (P4) and oestradiol (E2) secretion by porcine luteinised granulosa cells harvested from medium follicles, and (2) the mRNA and protein expression of oestrogen receptors α and β (ERα and ERβ) in these cells. The influence of E2 on P4 secretion and ERα and ERβ expression in the granulosa cells of pigs was also investigated. It was found that daidzein inhibited progesterone secretion by luteinised granulosa cells isolated from medium follicles. In contrast, E2 did not affect progesterone production by these cells. Moreover, daidzein did not alter the granulosal secretion of E2. Both daidzein and E2 decreased mRNA expression of ERα in the cells examined. The expression of ERβ mRNA was not affected by daidzein but was inhibited by E2. ERα protein was not detected while ERβ protein was found in the nuclei of the cells. Daidzein and E2 upregulated the expression of ERβ protein in the cells. In summary, the phytoestrogen daidzein directly affected the porcine ovary by inhibiting progesterone production and increasing ERβ protein expression. Daidzein-induced changes in follicular steroidogenesis and granulosal sensitivity to oestrogens may disturb reproductive processes in pigs.


2021 ◽  
Author(s):  
◽  
Zaramasina Clark

<p>The number of cycles of assisted reproductive technologies (ART) performed increased by ~9.5 % globally between 2008 and 2010. In spite of this, the success rate in terms of delivery was only ~19.0 % (Dyer et al., 2016). This discrepancy between the demand for, and success of, these technologies necessitates the development of tools to improve ART efficiency. To facilitate this, a better understanding of how the microenvironment changes within the developing follicle to culminate in a mature, developmentally-competent oocyte is required. This study employed an in vivo and in vitro ovine model to investigate the relationship between the surrounding microenvironment and oocyte maturation, and in particular, the attainment of oocyte developmental competency and high-quality embryos.  The first objective of this PhD study was to comprehensively investigate the changing microenvironment of in vivo matured, presumptive preovulatory (PPOV) follicles from wild-type (++) and high ovulation rate (OR; I+B+) ewes. The high OR ewes were heterozygous carriers of mutations in BMP15 (I+) and BMPRIB (B+). Functional differences in follicular somatic (granulosa and cumulus) cells between these genotypes, including differential gonadotropin responsiveness of granulosa cells, composition of follicular fluid and gene expression profiles in cumulus cells were evident. These differences emerged as part of a compensatory mechanism by which oocytes from smaller follicles, containing fewer granulosa cells, achieved developmental competency in I+B+ ewes.  The second objective of this PhD study was to develop new approaches for improving current in vitro maturation (IVM) strategies. The first approach utilised in this study focused on developing biomarkers that could be used to improve prediction of developmental competency in oocytes and in vitro produced embryos. This involved interrogating the hypothesis that a combination of molecular and morphokinetic biomarkers would better predict the developmental competency of oocytes and embryos compared to using these biomarkers alone. The second approach utilised in this PhD study tested the effects of modulating IVM conditions to better mimic the follicular microenvironment of a high, compared to a low, OR species on oocyte developmental competency and embryo quality. This involved supplementing IVM media with different ratios of two oocyte-secreted growth factors, i.e. GDF9:BMP15, that were representative of low or high OR species. These approaches demonstrated significant potential and warrant further investigation.  The most significant finding of this study was that despite variances in the surrounding microenvironment during in vivo and in vitro oocyte maturation that culminated in differential gene expression patterns in cumulus cells, and divergent gonadotropin-responsiveness of granulosa cells, the gene expression signatures of developmentally-competent oocytes and the morphokinetics of high-quality embryos were unaltered. This confirms the value of developing such biomarkers for oocyte development competency and embryo quality that remain unaltered despite a changing surrounding environment. Interestingly, simulating the ratio of GDF9:BMP15 that oocytes from high OR species are exposed to during maturation improved developmental competency in oocytes as demonstrated by increased blastocyst rates. Furthermore, this study has demonstrated that combinations of molecular (cumulus cell gene expression) and morphokinetic biomarkers improved the ability to predict developmental competency in oocytes and embryos. Overall, this study revealed novel information regarding the follicular microenvironment during final maturation and identified several novel approaches to improving the efficiency of ART.</p>


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