Role of Cumulus Cells in Oocyte Maturation

1982 ◽  
pp. 175-188 ◽  
Author(s):  
Torbjörn Hillensjö ◽  
Claes Magnusson ◽  
Carl Ekholm ◽  
Håkan Billig ◽  
Lars Hedin
Keyword(s):  
Oocyte Maturation ◽  
Cumulus Cells

scholarly journals Hypoxia-inducible factor (HIF1alpha) inhibition modulates cumulus cell function and affects bovine oocyte maturation in vitro†

2020 ◽  
Author(s):  
Aslihan Turhan ◽  
Miguel Tavares Pereira ◽  
Gerhard Schuler ◽  
Ulrich Bleul ◽  
Mariusz P Kowalewski
Keyword(s):  
Oocyte Maturation ◽  
Cell Function ◽  
Hypoxia Inducible Factor ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Negative Effects ◽  
Protein Levels ◽  
Maturation In Vitro

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.

176 REGULATORY ROLE OF miR-20a DURING BOVINE OOCYTE MATURATION

2017 ◽  
Vol 29 (1) ◽  
pp. 196 ◽  
Author(s):  
E. Andreas ◽  
D. Salilew-Wondim ◽  
F. Rings ◽  
E. Held ◽  
M. Hoelker ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Expression Analysis ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Fine Tuning ◽  
Bovine Oocyte ◽  
Total Rna ◽  
Progesterone Synthesis ◽  
Spent Media

The role of microRNA in oocyte maturation is mostly associated with optimal turnover of the accumulated maternal transcripts during their growth to allow maturation. MiR-20a is a member of the miR-17–92 cluster, which has been found to be differentially expressed in bovine granulosa cells derived from preovulatory dominant and subordinate follicles. Our recent study showed that miR-20a is involved in the regulation of granulosa cell proliferation, differentiation, and progesterone synthesis by targeting PTEN and BMPR2 genes. Here, we aimed to investigate the role of miR-20a in the bovine oocyte maturation processes. For this, cumulus-oocyte complexes (COC) were aspirated from small antral follicles (2–8 mm in diameter) and cultured in groups of 50 in 400 µL of maturation media (TCM-199 media supplemented with 12% oestrus cow serum and 10 µg/ml Follitropin®) at 39°C in a humidified atmosphere with 5% (vol/vol) CO2 in the air for 22 h. The cumulus cells and oocytes before (germinal vesicle) and after maturation (metaphase II) were mechanically separated in 0.1% hyaluronidase (in TCM-199 media). To study whether the presence of cumulus cells or oocyte has an impact on the miR-20a expression, we cultured oocytectomized cumulus cells and oocytes with and without their companion cells. Moreover, COC were co-cultured with miR-20a mimic, inhibitor, or corresponding controls to investigate the role of this miRNA in oocyte maturation. The total RNA from cumulus cells and oocytes was extracted using miRNeasy® mini kit (Qiagen GmbH, Hilden, Germany). Total RNA from respective samples was reverse transcribed for mRNA and microRNA expression analysis. Quantitative expression analysis was performed using StepOnePlus™ System (Applied Biosystems, Foster City, CA, USA) and subsequent data were analysed using a comparative cycle threshold method. The progesterone released in the spent media was measured using progesterone enzyme-linked immunosorbent assay kit (ENZO Life Sciences GmbH, Loerrach, Germany). Here, we found that miR-20a expression in cumulus cells increased (P < 0.05) during oocyte maturation. Conversely, miR-20a expression in metaphase II stage oocytes was significantly lower (P < 0.001) compared with the germinal vesicle stage. The absence of oocyte cytoplasm resulted in reduced miR-20a expression in cumulus cells. On the other hand, the absent of cumulus cells increased miR-20a expression in oocytes. The miR-20a expression revealed that the microRNA transduction is restricted in the cumulus cells. The overexpression of miR-20a increased oocyte maturation rate (P < 0.05) by 4.8% (as determined by extrusion of the polar body) and the expression of oocyte maturation-related genes (INHBA, MAPK1, PTGS2, PTX3, and EGFR). The progesterone released in spent media of COC co-cultured with miR-20a mimic and inhibitor showed increasing (P = 0.0936) and decreasing (P = 0.0993) trends, respectively. In this study, we also found that miR-20a modulation altered the expression of PTEN and BMPR2 in cumulus cells. In conclusion, the modulation of miR-20a expression in cumulus cells regulates the oocyte maturation and partially involved in the progesterone synthesis by fine-tuning the expression of PTEN and BMPR2 genes.

scholarly journals Lipids and oocyte developmental competence: the role of fatty acids and β-oxidation

Reproduction ◽  
2014 ◽  
Vol 148 (1) ◽  
pp. R15-R27 ◽  
Author(s):  
Kylie R Dunning ◽  
Darryl L Russell ◽  
Rebecca L Robker
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Embryo Development ◽  
Oocyte Maturation ◽  
Unsaturated Fatty Acids ◽  
Cumulus Cells ◽  
Developmental Competence ◽  
Oocyte Developmental Competence

Metabolism and ATP levels within the oocyte and adjacent cumulus cells are associated with quality of oocyte and optimal development of a healthy embryo. Lipid metabolism provides a potent source of energy and its importance during oocyte maturation is being increasingly recognised. The triglyceride and fatty acid composition of ovarian follicular fluid has been characterised for many species and is influenced by nutritional status (i.e. dietary fat, fasting, obesity and season) as well as lactation in cows. Lipid in oocytes is a primarily triglyceride of specific fatty acids which differ by species, stored in distinct droplet organelles that re-localise during oocyte maturation. The presence of lipids, particularly saturated vs unsaturated fatty acids, in in vitro maturation systems affects oocyte lipid content as well as developmental competence. Triglycerides are metabolised by lipases that have been localised to cumulus cells as well as oocytes. Fatty acids generated by lipolysis are further metabolised by β-oxidation in mitochondria for the production of ATP. β-oxidation is induced in cumulus–oocyte complexes (COCs) by the LH surge, and pharmacological inhibition of β-oxidation impairs oocyte maturation and embryo development. Promoting β-oxidation with l-carnitine improves embryo development in many species. Thus, fatty acid metabolism in the mammalian COC is regulated by maternal physiological and in vitro environmental conditions; and is important for oocyte developmental competence.

The regulatory role of miR-20a in bovine cumulus cells and its contribution to oocyte maturation

Zygote ◽  
2021 ◽  
pp. 1-10
Author(s):  
Eryk Andreas ◽  
Hari Om Pandey ◽  
Michael Hoelker ◽  
Dessie Salilew-Wondim ◽  
Samuel Gebremedhn ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Maturation Process ◽  
Progesterone Synthesis ◽  
Before And After ◽  
Maturation Rate ◽  
Transcriptional Gene Regulation

Summary Dynamic changes in microRNAs in oocyte and cumulus cells before and after maturation may explain the spatiotemporal post-transcriptional gene regulation within bovine follicular cells during the oocyte maturation process. miR-20a has been previously shown to regulate proliferation and differentiation as well as progesterone levels in cultured bovine granulosa cells. In the present study, we aimed to demonstrate the function of miR-20a during the bovine oocyte maturation process. Maturation of cumulus–oocyte complexes (COCs) was performed at 39°C in an humidified atmosphere with 5% CO2 in air. The expression of miR-20a was investigated in the cumulus cells and oocytes at 22 h post culture. The functional role of miR-20a was examined by modulating the expression of miR-20a in COCs during in vitro maturation (IVM). We found that the miR-20a expression was increased in cumulus cells but decreased in oocytes after IVM. Overexpression of miR-20a increased the oocyte maturation rate. Even though not statistically significant, miR-20a overexpression during IVM increased progesterone levels in the spent medium. This was further supported by the expression of STAR and CYP11A1 genes in cumulus cells. The phenotypes observed due to overexpression of miR-20a were validated by BMP15 supplementation during IVM and subsequent transfection of BMP15-treated COCs using miR-20a mimic or BMPR2 siRNA. We found that miR-20a mimic or BMPR2 siRNA transfection rescued BMP15-reduced oocyte maturation and progesterone levels. We concluded that miR-20a regulates oocyte maturation by increasing cumulus cell progesterone synthesis by simultaneous suppression of BMPR2 expression.

scholarly journals The Differential Metabolomes in Cumulus and Mural Granulosa Cells from Human Preovulatory Follicles

2021 ◽  
Author(s):  
Er-Meng Gao ◽  
Bongkoch Turathum ◽  
Ling Wang ◽  
Di Zhang ◽  
Yu-Bing Liu ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Granulosa Cells ◽  
Quantitative Polymerase Chain Reaction ◽  
Cumulus Cells ◽  
Cholesterol Transport ◽  
Vitro Fertilization ◽  
Expression Of Genes ◽  
Preovulatory Follicles ◽  
Morphological Differences

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.

scholarly journals Interactions between the WEE-1.3 kinase and the PAM-1 aminopeptidase in oocyte maturation and the early C. elegans embryo

2021 ◽  
Author(s):  
Dorothy Benton ◽  
Eva C Jaeger ◽  
Arielle Kilner ◽  
Ashley Kimble ◽  
Josh Lowry ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Oocyte Maturation ◽  
Protective Role ◽  
C Elegans ◽  
Direct Target ◽  
The One ◽  
Actomyosin Cytoskeleton ◽  
Embryonic Viability ◽  
Anterior Posterior

Abstract Puromycin-sensitive aminopeptidases are found across phyla and are known to regulate the cell-cycle and play a protective role in neurodegenerative disease. PAM-1 is a puromycin-sensitive aminopeptidase important for meiotic exit and polarity establishment in the one-cell Caenorhabditis elegans embryo. Despite conservation of this aminopeptidase, little is known about its targets during development. In order to identify novel interactors, we conducted a suppressor screen and isolated four suppressing mutations in three genes that partially rescued the maternal-effect lethality of pam-1 mutants. Suppressed strains show improved embryonic viability and polarization of the anterior-posterior axis. We identified a missense mutation in wee-1.3 in one of these suppressed strains. WEE-1.3 is an inhibitory kinase that regulates maturation promoting factor. While the missense mutation suppressed polarity phenotypes in pam-1, it does so without restoring centrosome-cortical contact or altering the cortical actomyosin cytoskeleton. To see if PAM-1 and WEE-1.3 interact in other processes, we examined oocyte maturation. While depletion of wee-1.3 causes sterility due to precocious oocyte maturation, this effect was lessened in pam-1 worms, suggesting that PAM-1 and WEE-1.3 interact in this process. Levels of WEE-1.3 were comparable between wild-type and pam-1 strains, suggesting that WEE-1.3 is not a direct target of the aminopeptidase. Thus, we have established an interaction between PAM-1 and WEE-1.3 in multiple developmental processes and have identified suppressors that are likely to further our understanding of the role of puromycin-sensitive aminopeptidases during development.

scholarly journals PACAP-mediated sperm–cumulus cell interaction promotes fertilization

Reproduction ◽  
2011 ◽  
Vol 141 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Ichiro Tanii ◽  
Tadashi Aradate ◽  
Kouhei Matsuda ◽  
Akira Komiya ◽  
Hideki Fuse
Keyword(s):  
Sperm Motility ◽  
Acrosome Reaction ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Cell Interaction ◽  
Fertilization Rate ◽  
Type I ◽  
Dependent Manner ◽  
Sperm Penetration

The developing acrosome in spermatids contains pituitary adenylate cyclase-activating polypeptide (PACAP). However, the role of the acrosomal PACAP remains unclear because it has not been detected in mature spermatids and sperm. We reinvestigated whether the sperm acrosome contains PACAP. An antiserum produced against PACAP reacted to the anterior acrosome in epididymal sperm fixed under mild conditions, suggesting that PACAP acts on oocytes and/or cumulus cells at the site of fertilization. Immunolabeling and RT-PCR demonstrated the presence of PACAP type I receptor, a PACAP-specific receptor, in postovulatory cumulus cells. To investigate the role of PACAP in fertilization, we pretreated cumulus–oocyte complexes with the polypeptide. At a low concentration of sperm, the fertilization rate was significantly enhanced by PACAP in a dose-dependent manner. Sperm penetration through the oocyte investment, cumulus layer, and zona pellucida was also enhanced by PACAP. The enhancement was probably due to an enhancement in sperm motility and the zona-induced acrosome reaction, which were stimulated by a cumulus cell-releasing factor. Indeed, PACAP treatment increased the secretion of progesterone from the cumulus–oocyte complexes. These results strongly suggest that in response to PACAP, cumulus cells release a soluble factor that probably stimulates sperm motility and the acrosome reaction, thereby promoting fertilization.

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