Effect of kit ligand on natriuretic peptide precursor C and oocyte maturation in cattle

In vitro maturation (IVM) of oocytes in cattle is inefficient, and there is great interest in the development of approaches to improve maturation and fertilization rates. Intraovarian signalling molecules are being explored as potential additives to IVM media. One such factor is kit ligand (KITL), which stimulates the growth of oocytes. We determined if KITL enhances oocyte maturation in cattle. The two main isoforms of KITL (KITL1 and KITL2) were expressed in bovine cumulus–oocyte complexes (COC), and levels of mRNA increased during FSH-stimulated IVM. The addition of KITL to the culture medium increased the percentage of oocytes that reached meiosis II but did not affect cumulus expansion after 22 h of IVM. Addition of KITL reduced the levels of mRNA encoding natriuretic peptide precursor C (NPPC), a protein that holds oocytes in meiotic arrest, and increased the levels of mRNA encoding YBX2, an oocyte-specific factor involved in meiosis. Removal of the oocyte from the COC resulted in increased KITL mRNA levels and decreased NPPC mRNA levels in cumulus cells, and addition of denuded oocytes reversed these effects. Taken together, our results suggest that KITL enhances bovine oocyte nuclear maturation through a mechanism that involves NPPC, and that the oocyte regulates cumulus expression of KITL mRNA.

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172 DETERMINING THE REQUIREMENTS FOR LH AND FSH DURING SHEEP IN VITRO OOCYTE MATURATION

Reproduction Fertility and Development ◽

10.1071/rdv26n1ab172 ◽

2014 ◽

Vol 26 (1) ◽

pp. 200 ◽

Cited By ~ 5

Author(s):

C. de Frutos ◽

R. Vicente-Perez ◽

P. J. Ross

Keyword(s):

Oocyte Maturation ◽

In Vitro Maturation ◽

Mixed Logit ◽

Cumulus Cells ◽

Pituitary Hormones ◽

Developmental Competence ◽

Cumulus Expansion ◽

Nuclear Maturation ◽

Grade 3

In vitro maturation (IVM) of oocytes in domestic animals is a widespread practice of research and commercial relevance. Gonadotropic hormones are typically supplemented to the IVM medium to stimulate resumption of meiosis, progression to metaphase II (MII), and oocyte developmental competence. The common use of pituitary-derived products presents 2 problems: contamination from other pituitary hormones and inconsistences from batch-to-batch variation. Recombinant hormones can help circumvent these issues and identify specific gonadotropin requirements for in vitro maturation. The aim of the present study was to determine the effect of supplementing recombinant bovine LH and/or FSH (AspenBio) to the maturation of ovine oocytes in terms of cumulus expansion and progression to the MII stage. Abattoir-derived sheep cumulus–oocyte complexes (COC) were obtained from 1- to 5-mm-diameter antral follicles by ovary slicing. Oocytes with a homogeneous cytoplasm surrounded by at least 3 layers of cumulus cells were selected and cultured in serum-free IVM medium (Cotterill et al. 2012 Reproduction 144, 195–207) at 38.5°C and 5% CO2. The COC obtained from 8 replicates were allocated into 4 experimental groups: (1) no hormones; (2) 1.5 μg mL–1 recombinant bovine LH (rbLH); (3) 1.5 μg mL–1 recombinant bovine FSH (rbFSH); and (4) rbLH and rbFSH. The expansion of cumulus cells was recorded in each group after 24 h of IVM and COC classified as (1) very poor or no cumulus expansion (grade 1); (2) limited cumulus expansion (grade 2); and (3) full cumulus expansion (grade 3). Nuclear maturation in the 4 treatments was evaluated by assessing progression to the MII stage via DNA staining with Hoechst 33342 and fluorescence imaging. The effect of treatment on the observed proportion of MII oocytes was evaluated using a mixed logit model including treatment and replicate as fixed and random effects, respectively. Culture in IVM medium in the absence of gonadotropins or in the presence of rbLH resulted in poor cumulus expansion (grade 1). The supplementation of IVM medium with rbFSH (with or without rbLH) yielded a high degree of cumulus expansion (grades 2–3). Likewise, addition of rbFSH enhanced progression of oocytes to the MII stage, whereas use of rbLH, although it had an effect on progression to MII, did not augment the effect of rbFSH (Table 1). These results indicate that rbFSH is necessary and sufficient to induce sheep oocyte maturation in a high proportion of oocytes. Table 1.Cumulus expansion and oocyte nuclear stage after IVM

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Effect of butafosfan supplementation during oocyte maturation on bovine embryo development

Zygote ◽

10.1017/s0967199419000327 ◽

2019 ◽

Vol 27 (05) ◽

pp. 321-328

Author(s):

Lucas Teixeira Hax ◽

Joao Alveiro Alvarado Rincón ◽

Augusto Schneider ◽

Lígia Margareth Cantarelli Pegoraro ◽

Letícia Franco Collares ◽

...

Keyword(s):

Gene Expression ◽

Embryo Development ◽

Oocyte Maturation ◽

Cumulus Cells ◽

Oocyte Quality ◽

Bovine Embryo ◽

Cleavage Rate ◽

Nuclear Maturation

SummaryAround 60–80% of oocytes maturated in vivo reached competence, while the proportion of maturation in vitro is rarely higher than 40%. In this sense, butafosfan has been used in vivo to improve metabolic condition of postpartum cows, and can represent an alternative to increase reproductive efficiency in cows. The aim of this study was to evaluate the addition of increasing doses of butafosfan during oocyte maturation in vitro on the initial embryo development in cattle. In total, 1400 cumulus–oocyte complexes (COCs) were distributed in four groups and maturated according to supplementation with increasing concentrations of butafosfan (0 mg/ml, 0.05 mg/ml, 0.1 mg/ml and 0.2 mg/ml). Then, 20 oocytes per group were collected to evaluate nuclear maturation and gene expression on cumulus cells and oocytes and the remaining oocytes were inseminated and cultured until day 7, when blastocysts were collected for gene expression analysis. A dose-dependent effect of butafosfan was observed, with decrease of cleavage rate and embryo development with higher doses. No difference between groups was observed in maturation rate and expression of genes related to oocyte quality. Our results suggest that butafosfan is prejudicial for oocytes, compromising cleavage and embryo development.

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Effects of ghrelin on activation of Akt1 and ERK1/2 pathways during in vitro maturation of bovine oocytes

Zygote ◽

10.1017/s096719941700003x ◽

2017 ◽

Vol 25 (2) ◽

pp. 183-189 ◽

Cited By ~ 11

Author(s):

Thomas-Markos Chouzouris ◽

Eleni Dovolou ◽

Fotini Krania ◽

Ioannis S. Pappas ◽

Konstantinos Dafopoulos ◽

...

Keyword(s):

Oocyte Maturation ◽

Cumulus Cells ◽

Treated Group ◽

Control Group ◽

Dependent Manner ◽

Nuclear Maturation ◽

Bovine Oocytes ◽

Phosphorylation Rate ◽

Matured Oocyte

SummaryThe purpose of this study was to investigate the possible molecular pathways through which ghrelin accelerates in vitro oocyte maturation. Bovine cumulus–oocyte complexes (COCs), after 18 or 24 h maturation in the absence or the presence of 800 pg ml–1 of acylated ghrelin were either assessed for nuclear maturation or underwent in vitro fertilization in standard media and putative zygotes were cultured in vitro for 8 days. In a subset of COCs the levels of phosphorylated Akt1 and ERK1/2 (MAPK1/3) were assessed at the 0th, 6th, 10th, 18th and 24th hours of in vitro maturation (IVM). At 18 and 24 h no difference existed in the proportion of matured oocytes in the ghrelin-treated group, while in the control group more (P < 0.05) matured oocyte were found at 24 h. Oocyte maturation for 24 h in the presence of ghrelin resulted in substantially reduced (P < 0.05) blastocyst yield(16.3%) in comparison with that obtained after 18 h (30.0%) or to both control groups (29.3% and 26.9%, for 18 and 24 h in maturation, respectively). Ghrelin-treated oocytes expressed lower Akt1 phosphorylation rate at the 10th hour of IVM, and higher ERK1/2 at the 6th and 10th hours of IVM compared with controls. In cumulus cells, at the 18th and 24th hours of IVM Akt1 phosphorylation rate was higher in ghrelin-treated oocytes. Our results imply that ghrelin acts in a different time-dependent manner on bovine oocytes and cumulus cells modulating Akt1 and ERK1/2 phosphorylation, which brings about acceleration of the oocyte maturation process.

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146. MOLECULAR FILTRATION PROPERTIES OF THE EXPANDED CUMULUS MATRIX: CONTROLLED SUPPLY OF METABOLITES AND EXTRACELLULAR SIGNALS TO CUMULUS CELLS AND THE OOCYTE

Reproduction Fertility and Development ◽

10.1071/srb10abs146 ◽

2010 ◽

Vol 22 (9) ◽

pp. 64

Author(s):

K. R. Dunning ◽

L. N. Watson ◽

J. G. Thompson ◽

R. L. Robker ◽

D. L. Russell

Keyword(s):

Oocyte Maturation ◽

In Vitro Maturation ◽

Cumulus Cells ◽

Oocyte Quality ◽

Oocyte Competence ◽

Signalling Molecules ◽

The Matrix ◽

Filtration Properties

Cumulus matrix genes are positively correlated with oocyte competence [1]. Formation of the expanded cumulus matrix during oocyte maturation is well described; however its function remains elusive. We investigated whether cumulus matrix acts as a molecular filter, based on recognised filtration properties of analogous matrices. We found that cumulus matrix controls metabolite supply to the oocyte and retains prostaglandin E2 (PGE2), which is critical in oocyte maturation. The uptake of fluorescently labelled hydrophilic and hydrophobic metabolites showed that cumulus matrix formation significantly impeded diffusion to the oocyte. Expanded in vivo matured cumulus oocyte complexes (COCs, eCG+hCG16h) resisted uptake of glucose and cholesterol compared to unexpanded (eCG44h, P < 0.05), as assessed by confocal microscopy and spatial quantitation of fluorescence (P < 0.05). In vitro maturation (IVM) results in pronounced compositional deficiency of cumulus matrix proteins [2] and poor oocyte quality. Glucose and cholesterol were transported more readily into cumulus cells and the oocyte of IVM COCs (matured in αMEM/5% FCS/50 mIU/mL FSH, 16 h) compared to in vivo matured COCs (P < 0.05 and P = 0.08, respectively). Taking the inverse approach we found that PGE2 synthesised by cumulus cells is retained within the matrix compartment of in vivo matured COCs but IVM COCs did not retain PGE2 and secreted 4.3-fold more into the media. The relationship of retained to secreted PGE2 was significantly higher after in vivo maturation vs IVM COCs (P < 0.0001). This property of the COC matrix reveals a potential mechanism whereby the prostaglandin signal intensifies through a physicochemical mechanism rather than gene regulation. This is the first demonstration that cumulus matrix regulates diffusion toward and secretion from the COC, thus excluding glucose, known to negatively affect oocyte quality, and trapping factors, including PGE2, with critical roles in oocyte maturation and fertilisation. Thus, IVM may reduce oocyte quality due to poor trafficking of metabolites and signalling molecules. (1) McKenzie LJ, et al. Human cumulus granulosa cell gene expression: a predictor of fertilization and embryo selection in women undergoing IVF. Hum Reprod 2004; 19: 2869–2874.(2) Dunning KR, et al. Altered composition of the cumulus-oocyte complex matrix during in vitro maturation of oocytes. Hum Reprod 2007; 22: 2842–2850.

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Octylphenol, an environmental oestrogen, affects oocyte maturation in cattle

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200004464 ◽

2001 ◽

Vol 2001 ◽

pp. 64-64 ◽

Cited By ~ 1

Author(s):

P Pocar ◽

R Augustin ◽

F Gandolfi ◽

B Fischer

Keyword(s):

Oocyte Maturation ◽

Nonionic Surfactants ◽

Cumulus Cells ◽

Model System ◽

Animal Cells ◽

Nuclear Maturation ◽

Maturation In Vitro ◽

Bovine Oocytes

4-tert-octylphenol (OP) is an alkylphenolic compound formed as metabolite of some nonionic surfactants that are widely used in industrial detergents, as plastic additives, dispersant for insecticides, etc. (Naylor et al., 1992). OP accumulates in adipose tissue. Micromolar concentrations of these compounds may constitute health hazards to animal cells. Furthermore, it has previously been shown to exert oestrogenic activity in vivo and in vitro (White et al., 1994). A growing concern about “endocrine disruptors” and their impact on oestrogen-dependent phenomena led us investigate the effects of OP on oocyte maturation. For variuos reasons bovine oocytes were chosen as the model system. We examined the effects of OP exposure on oocyte nuclear maturation in vitro and on the expression of oestrogen receptors in cumulus cells.

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Contribution of cumulus cells and serum to the maturation of oocyte cytoplasm as revealed by intracytoplasmic sperm injection (ICSI)

Zygote ◽

10.1017/s0967199401001307 ◽

2001 ◽

Vol 9 (4) ◽

pp. 277-282 ◽

Cited By ~ 23

Author(s):

Yukiko Yamazaki ◽

Teruhiko Wakayama ◽

Ryuzo Yanagimachi

Keyword(s):

Oocyte Maturation ◽

Intracytoplasmic Sperm Injection ◽

Germinal Vesicle ◽

Cumulus Cells ◽

Serum Free ◽

Nuclear Maturation ◽

Normal Term ◽

Developmental Capacity ◽

Oocyte Cytoplasm

The fertilisability and developmental capacity of mouse oocytes matured in vitro were examined by in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI). While more than 50% of cumulus-enclosed oocytes were fertilised by IVF after maturation in serum-supplemented medium, none were fertilised when the oocytes matured without serum. By ICSI, the majority (78-94%) of the oocytes were fertilised regardless of the presence or absence of serum in oocyte maturation media. Although the majority (88-92%) of cumulus-free germinal vesicle oocytes underwent nuclear maturation in both serum-free and serum-containing media, those matured in the presence of serum were more readily fertilised by ICSI (43%) than those matured without it (3-5%). The cumulus-free oocytes co-cultured with cumulus cells but without serum were fertilised at 36%, suggesting some secreted factor promotes the oocyte's cytoplasmic maturation. The oocytes fertilised by ICSI developed into normal-term fetuses regardless of the presence or absence of serum or cumulus cells in oocyte maturation medium. These results lead us to conclude that (a) the cytoplasm of the oocytes can mature in serum-free medium and (b) the presence of both the serum and the cumulus cells in the medium surrounding maturing oocytes is beneficial for the development of the fertilisation- and development-competence of oocyte cytoplasm.

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283 EFFECTS OF CUMULUS CELL REMOVAL ON IN VITRO OOCYTE MATURATION, FERTILIZATION, AND EMBRYONIC DEVELOPMENT IN PIGS

Reproduction Fertility and Development ◽

10.1071/rdv18n2ab283 ◽

2006 ◽

Vol 18 (2) ◽

pp. 249 ◽

Cited By ~ 1

Author(s):

N. Maedomari ◽

N. Kashiwazaki ◽

M. Ozawa ◽

A. Takizawa ◽

J. Noguchi ◽

...

Keyword(s):

Embryonic Development ◽

Oocyte Maturation ◽

Polar Body ◽

Cumulus Cell ◽

Cumulus Cells ◽

Blastocyst Stage ◽

Control Group ◽

Nuclear Maturation ◽

First Polar Body

It is generally accepted that cumulus cells (CCs) support the nuclear maturation of immature oocytes in mammals. However, the precise mechanism of interaction between cumulus cells and oocytes has not been clarified. Furthermore, the role of cumulus cells in embryonic development has not been reported. In the present study, the effect of denuding cumulus cells from porcine oocytes on oocyte maturation, ertilization, and their subsequent development to the blastocyst stage was examined in vitro. In vitro maturation, fertilization, and culture were carried out as previously reported (Kikuchi et al. 2002 Biol. Reprod. 66, 1033-1041). Porcine cumulus-oocyte complexes (COCs) were collected; some of them were completely denuded of cumulus cells immediately after the collection (DO-0 group). The remaining intact COCs and the DO-0 oocytes were cultured for 24 h in the presence of dbcAMP and hormones. After the initial culture, some of the intact COCs were denuded either completely (DO-24 group) or partially (H-DO-24 group). Additionally, some of DO-24 oocytes were co-cultured with the cumulus cells removed at 0 h and pre-cultured for 24 h (DO-24 + CCs group). The denuded oocytes in each experimental group and intact COCs (control) were further cultured for total 46 h. The remaining oocytes with a first polar body were either examined for the levels of intracellular glutathione (GSH) or fertilized in vitro with frozen-thawed boar spermatozoa. The inseminated oocytes were cultured and examined for their fertilization status after 10 h and for their developmental competence after 6 days. Data were analyzed by ANOVA, followed by the Duncan's multiple range tests. The maturation rates of all denuded groups were significantly lower (P < 0.05; 34.3 to 45.0%) than that of the control group (64.5%). Intracellular GSH concentrations of all denuded groups were also significantly lower (P < 0.05; 4.03 to 7.00 pmol/oocyte) than that of the control group (9.60 pmol/oocyte); however, the GSH level of H-DO-24 oocytes was significantly higher (P < 0.05) than the GSH levels in the other denuded groups. Male pronuclear formation rates of completely denuded oocytes (DO-0, DO-24, and DO-24 + CCs groups) were significantly lower (P < 0.05; 41.4 to 59.3%) than those of the control (89.4%) and the H-DO-24 (80.0%) groups. The blastocyst rate of the control group was significantly higher (P < 0.05; 19.9%) than that of H-DO-24 group (11.6%), and these rates were significantly higher (P < 0.05) than those of the completely denuded groups (3.0 to 4.5%). The results suggest that the presence of cumulus cells during maturation culture improves nuclear maturation of oocytes and plays an important role in embryonic development to the blastocyst stage in vitro.

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182 EFFECTS OF IGF-1 OR IGF-1-LongR3 ON CELLULAR AND MOLECULAR ASPECTS OF CUMULUS-OOCYTE COMPLEXES DURING IN VITRO OOCYTE MATURATION IN CATTLE

Reproduction Fertility and Development ◽

10.1071/rdv28n2ab182 ◽

2016 ◽

Vol 28 (2) ◽

pp. 222

Author(s):

M. S. Araujo ◽

M. D. Guastali ◽

A. C. S. Castilho ◽

F. Landim-Alvarenga

Keyword(s):

Gene Expression ◽

Oocyte Maturation ◽

Cumulus Cell ◽

Cumulus Cells ◽

Synthetic Analogue ◽

Nuclear Maturation ◽

Meiotic Progression ◽

Metaphase Stage ◽

Bovine Oocytes

The insulin-like growth factor-1 recombinant -3 (IGF-1-LongR3), a synthetic analogue of IGF-1 with increased bioavailability has not yet been used in vitro maturation (IVM) medium of bovine oocytes. Therefore, the aim of this study was to evaluate and compare the addition effects of IGF-1-LongR3 or IGF-1 in IVM bovine oocytes on meiotic progression, apoptosis, and profile of oocytes genes (GDF9, BMP15, BAX, BCL2, OOSP1, IGFBP2, IGFBP4 and IGFBP5) and genes in cumulus cells (AREG, EGFR, FSHR, COX2, BAX, BCL2, IGFBP2, IGFBP4 and IGFBP5). Bovine ovaries were collected in slaughterhouses, and 739 oocytes with grades 1 or 2 were selected after aspiration of 2- to 8-mm follicles. IVM was carried out in TCM199 with FSH, LH, and antibiotics (BM) supplemented with 100 ng mL–1 IGF-1 or 100 ng mL–1 LongR3-IGF-1. Control oocytes were matured in BM supplemented with 0.1% polyvinyl alcohol (PVA) or 10% FCS. For all groups, maturation was performed during 22–24 h in an incubator at 38.5°C and 5% CO2 in air. Subsequently oocytes were denuded and analysed for apoptosis, nuclear maturation, and gene expression by TUNEL assay, staining Hoechst 33342, and RT-qPCR, respectively. Statistical analysis was performed using a linear mixed effects model, which correlated the change in metaphase stage 1 to 2 and the absence of apoptosis among the experimental groups. ANOVA and Tukey tests were used to analyse the results obtained by RT-qPCR. After 10 replicates of IVM, 339 oocytes were evaluated for meiotic progression and apoptosis and 400 oocytes for gene expression. There was no statistical difference between the experimental groups with respect to meiotic progression and apoptosis. BCL2 and IGFBP4 gene were less expressed in oocytes matured with IGF-1 and LongR3-IGF-1 compared with control groups. GFBP4 was also less expressed in cumulus cell of oocytes from the experimental groups. Moreover COX2 expression was statistically elevated in cumulus cells matured in the presence of IGF-1 and LongR3-IGF-1 It was possible to perform IVM of bovine oocytes in the presence of LongR3-IGF-1, allowing its use in replacement of IGF-1 and FCS. The results of this study will provide more information on the interaction of IGF with the IGFBP and its importance for oocyte maturation.

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Steroid hormones interact with natriuretic peptide C to delay nuclear maturation, to maintain oocyte–cumulus communication and to improve the quality of in vitro-produced embryos in cattle

Reproduction Fertility and Development ◽

10.1071/rd16320 ◽

2017 ◽

Vol 29 (11) ◽

pp. 2217 ◽

Cited By ~ 10

Author(s):

Ana Caroline S. Soares ◽

Valentina Lodde ◽

Rodrigo G. Barros ◽

Christopher A. Price ◽

Alberto M. Luciano ◽

...

Keyword(s):

Steroid Hormones ◽

Natriuretic Peptide ◽

Lucifer Yellow ◽

Cumulus Cells ◽

Cell Number ◽

Developmental Competence ◽

Germinal Vesicle Breakdown ◽

Nuclear Maturation

In vivo, oocyte maturation is triggered by the ovulatory LH surge, whereas in vitro it is precociously induced when the cumulus–oocyte complex is removed from the follicle. Natriuretic peptide C (NPPC) delays germinal vesicle breakdown (GVBD) while increasing oocyte–cumulus communication during in vitro maturation (IVM) in cattle. In the present study we first tested the hypothesis that steroids secreted by the follicle (17β-oestradiol, progesterone and androstenedione) interact with NPPC to delay GVBD and to maintain oocyte–cumulus communication as assessed by transfer of a dye (Lucifer Yellow) from the oocyte to cumulus cells. Then, we assessed the effects of steroid hormones and NPPC, alone and in combination in a pre-IVM culture, on embryo production. The combination of NPPC with steroids delayed GVDB, increased natriuretic peptide receptor 2 (NPR2) mRNA abundance in cumulus cells during culture, and maintained oocyte–cumulus communication at levels not different from non-cultured controls. The addition of steroids and/or NPPC to a pre-IVM culture did not alter blastocyst rates after IVF, but supplementation with steroids increased blastocyst total cell number. The present study provides evidence, for the first time in cattle, that steroids interact with NPPC to regulate oocyte nuclear maturation and oocyte–cumulus communication, and improve oocyte developmental competence.

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

Reproductive Sciences ◽

10.1007/s43032-021-00691-3 ◽

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.

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