scholarly journals Molecular analysis of the cumulus matrix: insights from mice with O-glycan-deficient oocytes

Reproduction ◽  
2015 ◽  
Vol 149 (5) ◽  
pp. 533-543 ◽  
Author(s):  
Panayiota Ploutarchou ◽  
Pedro Melo ◽  
Anthony J Day ◽  
Caroline M Milner ◽  
Suzannah A Williams

During follicle development, oocytes secrete factors that influence the development of granulosa and cumulus cells (CCs). In response to oocyte and somatic cell signals, CCs produce extracellular matrix (ECM) molecules resulting in cumulus expansion, which is essential for ovulation, fertilisation, and is predictive of oocyte quality. The cumulus ECM is largely made up of hyaluronan (HA), TNF-stimulated gene-6 (TSG-6, also known as TNFAIP6), pentraxin-3 (PTX3), and the heavy chains (HCs) of serum-derived inter-α-inhibitor proteins. In contrast to other in vivo models where modified expansion impairs fertility, the cumulus mass of C1galt1 Mutants, which have oocyte-specific deletion of core 1-derived O-glycans, is modified without impairing fertility. In this report, we used C1galt1 Mutant (C1galt1FF:ZP3Cre) and Control (C1galt1FF) mice to investigate how cumulus expansion is affected by oocyte-specific deletion of core 1-derived O-glycans without adversely affecting oocyte quality. Mutant cumulus–oocyte complexes (COCs) are smaller than Controls, with fewer CCs. Interestingly, the CCs in Mutant mice are functionally normal as each cell produced normal levels of the ECM molecules HA, TSG-6, and PTX3. However, HC levels were elevated in Mutant COCs. These data reveal that oocyte glycoproteins carrying core 1-derived O-glycans have a regulatory role in COC development. In addition, our study of Controls indicates that a functional COC can form provided all essential components are present above a minimum threshold level, and thus some variation in ECM composition does not adversely affect oocyte development, ovulation or fertilisation. These data have important implications for IVF and the use of cumulus expansion as a criterion for oocyte assessment.

2019 ◽  
Vol 31 (3) ◽  
pp. 529 ◽  
Author(s):  
Belinda K. M. Lo ◽  
Agnes Archibong-Omon ◽  
Panayiota Ploutarchou ◽  
Anthony J. Day ◽  
Caroline M. Milner ◽  
...  

Cumulus–oocyte complex (COC) expansion is essential for ovulation and fertilisation and is linked to oocyte quality. Hyaluronan (HA), the major matrix constituent, is cross-linked via inter-α-inhibitor heavy chains (HCs), pentraxin 3 (PTX3) and tumour necrosis factor-stimulated gene 6 (TSG-6). All except HCs are secreted by cumulus cells in response to oocyte-secreted factors, which signal via SMAD pathways. The double mutant (DM) mouse generates oocytes lacking complex N- and O-glycans due to oocyte-specific deletion of core 1 β1,3-galactosyltransferase (C1galt1) and N-acetylglucosaminyltransferase I (Mgat1) and has modified cumulus expansion. We compared COCs before expansion (48 h-post-pregnant mare serum gonadotrophin (PMSG)) and at late-stage expansion (9 h-post-human chorionic gonadotrophin (hCG); control n=3 mice, DM n=3 per group). Using histochemistry the levels of HA, HCs, PTX3, TSG-6 and phosphorylated-SMAD1/5/8 and -SMAD2 (12–25 COCs per group) were assessed. DM COCs did not differ from Controls in cumulus size or cell density at 9 h-post-hCG; however, HA and HC levels and phosphorylated-SMAD1/5/8 were reduced. Furthermore, no correlations were found between the levels of matrix molecules and cumulus area in DM or Control samples. These data suggest that HA and HCs can support cumulus expansion provided that they are present above minimum threshold levels. We propose that oocyte-specific ablation of C1galt1 and Mgat1 may affect bone morphogenetic protein 15 synthesis or bioactivity, thereby reducing SMAD1/5/8 phosphorylation and HA production.


Zygote ◽  
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 ◽  
...  

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.


2011 ◽  
Vol 23 (6) ◽  
pp. 788 ◽  
Author(s):  
D. R. Li ◽  
G. S. Qin ◽  
Y. M. Wei ◽  
F. H. Lu ◽  
Q. S. Huang ◽  
...  

This study was carried out to test the feasibility of enhancing embryo production in vivo and in vitro by immunoneutralisation against inhibin or follistatin. In Experiment 1, multi-parity buffaloes were assigned into three groups: High group (n = 8), which received one primary (2 mg) and two booster (1 mg) vaccinations (28-day intervals) with a recombinant inhibin α subunit in 1 mL of white oil adjuvant; Low group (n = 8), which received half that dose; and Control group (n = 7), which received only adjuvant. Immunisation against inhibin stimulated development of ovarian follicles. Following superovulation and artificial insemination, inhibin-immunised buffaloes had more developing follicles than the Control buffaloes. The average number of embryos and unfertilised ova (4.5 ± 0.6, n = 6) in the High group was higher (P < 0.05) than in the Control group (2.8 ± 0.6, n = 5) and was intermediate (4.1 ± 0.7, n = 7) in the Low group. The pooled number of transferable embryos of the High and Low groups (3.2 ± 0.5, n = 13) was also higher (P < 0.05) than that (1.6 ± 0.7, n = 5) of the controls. The immunised groups also had higher plasma concentrations of activin, oestradiol and progesterone. In Experiment 2, the addition of anti-inhibin or anti-follistatin antibodies into buffalo oocyte IVM maturation medium significantly improved oocyte maturation and cleavage rates following parthenogenic activation. Treatment with anti-follistatin antibody also doubled the blastocyst yield from activated embryos. These results demonstrated that immunisation against inhibin stimulated follicular development, enhanced oocyte quality and maturation competence, yielded more and better embryos both in vivo and in vitro.


2008 ◽  
Vol 20 (9) ◽  
pp. 108
Author(s):  
K. R. Dunning ◽  
L. K. Akison ◽  
D. L. Russell ◽  
R. J. Norman ◽  
R. L. Robker

In vivo, the oocyte matures in a niche environment surrounded by somatic cells, and later in ovarian follicular development, by follicular fluid. Maternal diet influences the environment in which an oocyte matures but the mechanisms by which an altered metabolic profile, such as hyperinsulinemia, affects oocyte quality are not known. We investigated the use of a three dimensional follicle culture system allowing direct manipulation of the follicular environment thus circumventing systemic hormonal and metabolic effects. Secondary follicles (113.4 ± 1.02µm, n = 54) were isolated from mice at d12, encapsulated individually in 2µl of alginate matrix, and cultured in aMEM/5%FCS/10 mIU/mL LH/100 mIU FSH at 37°C/5%CO2, with media sampling and replacement every second day. Following 12 days of culture there was a significant 3-fold increase in follicle diameter (320 ± 10.1µm, n = 51). Histological analysis showed normal follicular morphology and antrum formation. Analysis of oestradiol (15.0ng/mL), androstenedione (7.8ng/mL) and progesterone (23.7ng/mL) in the media at d12 confirmed normal steroidogenesis and differentiation. Treatment of follicles with an ovulatory stimulus (1.5IU/mL hCG/5ng/mL Egf), resulted in cumulus expansion and hyaluronan localising to the cumulus oocyte complex (COC) and follicular basement membrane. These analyses were consistent with follicle growth and induction of ovulation in vivo. Further, COCs isolated from follicles and matured in vitro (IVM) in the presence of Egf and FSH, underwent cumulus expansion (CEI 2.8 ± 0.2) and were capable of fertilisation and blastocyst development. LH did not induce IVM COC expansion (CEI 1.36 ± 0.2), reflecting the normal in vivo differentiation process. However, culturing follicles in high insulin (5ug/mL) led to a significant increase in the degree of IVM cumulus expansion in response to LH (CEI 2.1 ± 0.3) indicating inappropriate cumulus cell differentiation, which may lead to poorer oocyte quality. These results demonstrate that this technique recapitulates normal in vivo folliculogenesis and is useful for manipulation of the follicular environment and assessment of oocyte outcomes.


2012 ◽  
Vol 302 (12) ◽  
pp. E1511-E1518 ◽  
Author(s):  
Qiang Wang ◽  
Maggie M. Chi ◽  
Tim Schedl ◽  
Kelle H. Moley

Glucose is an essential nutrient for mammalian cells. Emerging evidence suggests that glucose within the oocyte regulates meiotic maturation. However, it remains controversial as to whether, and if so how, glucose enters oocytes within cumulus-oocyte complexes (COCs). We used a fluorescent glucose derivative (6-NBDG) to trace glucose transport within live mouse COCs and employed inhibitors of glucose transporters (GLUTs) and gap junction proteins to examine their distinct roles in glucose uptake by cumulus cells and the oocyte. We showed that fluorescent glucose enters both cumulus-enclosed and denuded oocytes. Treating COCs with GLUT inhibitors leads to simultaneous decreases in glucose uptake in cumulus cells and the surrounded oocyte but no effect on denuded oocytes. Pharmacological blockade of of gap junctions between the oocyte and cumulus cells significantly inhibited fluorescent glucose transport to oocytes. Moreover, we find that both in vivo hyperglycemic environment and in vitro high-glucose culture increase free glucose levels in oocytes via gap junctional channels. These findings reveal an intercellular pathway for glucose transport into oocytes: glucose is taken up by cumulus cells via the GLUT system and then transferred into the oocyte through gap junctions. This intercellular pathway may partly mediate the effects of high-glucose condition on oocyte quality.


2017 ◽  
Vol 114 (29) ◽  
pp. E5796-E5804 ◽  
Author(s):  
Ye Yuan ◽  
Lee D. Spate ◽  
Bethany K. Redel ◽  
Yuchen Tian ◽  
Jie Zhou ◽  
...  

Assisted reproductive technologies in all mammals are critically dependent on the quality of the oocytes used to produce embryos. For reasons not fully clear, oocytes matured in vitro tend to be much less competent to become fertilized, advance to the blastocyst stage, and give rise to live young than their in vivo-produced counterparts, particularly if they are derived from immature females. Here we show that a chemically defined maturation medium supplemented with three cytokines (FGF2, LIF, and IGF1) in combination, so-called “FLI medium,” improves nuclear maturation of oocytes in cumulus–oocyte complexes derived from immature pig ovaries and provides a twofold increase in the efficiency of blastocyst production after in vitro fertilization. Transfer of such blastocysts to recipient females doubles mean litter size to about nine piglets per litter. Maturation of oocytes in FLI medium, therefore, effectively provides a fourfold increase in piglets born per oocyte collected. As they progress in culture, the FLI-matured cumulus–oocyte complexes display distinctly different kinetics of MAPK activation in the cumulus cells, much increased cumulus cell expansion, and an accelerated severance of cytoplasmic projections between the cumulus cells outside the zona pellucida and the oocyte within. These events likely underpin the improvement in oocyte quality achieved by using the FLI medium.


2009 ◽  
Vol 21 (1) ◽  
pp. 184
Author(s):  
E. A. M. Amorim ◽  
L. S. Amorim ◽  
C. A. A. Torres ◽  
J. D. Guimãres ◽  
J. F. Fonseca ◽  
...  

Protein and urea concentrations impair oocyte and embryo development in vivo and in vitro through an unclear mechanism. A possible way to understand this process is to determine the concentration of hormones and metabolites in follicular fluid associated with normal development. The objective of this study was to determine the effect of dietary urea levels on follicular fluid concentration of hormones and metabolites and oocyte quality. A trial was conducted with 9 nonpregnant and nonlactating Saanen goats, which had been distributed in a randomized design and fed with diets with 0 (n = 4) and 2.4% of urea in the total dry matter (DM) of the diet (n = 5). Before follicle aspiration by laparotomy, the goats were synchronized by inserting intravaginal sponges containing 60 mg of acetate medroxyprogesterone (Progespon®, Sintex) for 10 days followed by 125 μg of cloprostenol (Ciosin® Coopers) 48 h before the removal of the sponge. The sponge was removed immediately before the follicular aspiration. The follicular development was stimulated with 70 mg of NIH-FSH-P1 (Folltropin V® Vetrepharm) i.m., and 300 IU of eCG i.m., (Novormon® Sintex) given 36 h before the follicular aspiration. Fluid from the 2 lartest follicles of each ovary were analyzed to determine the concentration of estradiol, progesterone, and testosterone by quimioluminesence, and glucose and urea concentrations were measured by enzymatic kit. The other follicles in each ovary were aspired with new needles and syringes and the oocyte quality was recorded. Oocytes were classified according to cytoplasma aspect and number of granulosa cells: Class A (dark cytoplasm and uniform aspect) with 3 (AMG) and <3 layers of cumulus cells (AmG); class B (cytoplasm with color alterations, desuniform aspect and vacuoles) with 3 (BMG) and <3 layers of cumulus cells (BmG); number of partially denuded oocytes (PD) and number of denuded oocytes (DO). Data were analyzed by ANOVA and treatment difference separated by SNK test. Follicular fluid estradiol concentration was lower in goats fed with urea (4.02 ± 0.16; 4.97 ± 0.18 ng mL–1; P < 0.05), progesterone concentration did not differ between treatments (2.48 ± 0.58; 3.37 ± 0.52 ng mL–1; P > 0.05), testosterone concentration was lower in the control animals (1.17 ± 0.48; 3.20 ± 0.43 ng mL–1; P < 0.05). The glucose (91.44 ± 3.60; 84.78 ± 5.58 mg dL–1) and urea concentration (23.04 ± 1.06; 18.00 ± 2.35) were greater in the animals treated with 2.4% compared with 0% of urea (P < 0.05), respectively. The number of oocytes in the different categories was not affected by treatment (P > 0.05): AMG 1.20 ± 1.09 v. 0.50 ± 0.57, AmG 4.20 ± 2.16 v. 3.50 ± 3.10, BMG 0.40 ± 0.54 v. 0.25 ± 0.50, BmG 1.40 ± 0.54 v. 1.75 ± 1.25, DO 10.20 ± 3.76 v. 11.50 ± 5.44, in the 0 and 2.4% of urea groups respectively. Only the number of PD (1.60 ± 0.54 v. 3.50 ± 1.91) recovered from animals treated with 2.4% was greater than in controls (P < 0.05). The hormone and metabolites concentration in follicular fluid as well as the oocyte quality was affected by the urea concentration of the diet. Supported by grant from: CNPq, FAPEMIG, Shering Plough®, Tecnopec®, Carbogel®.


2010 ◽  
Vol 22 (9) ◽  
pp. 64
Author(s):  
K. R. Dunning ◽  
L. N. Watson ◽  
J. G. Thompson ◽  
R. L. Robker ◽  
D. L. Russell

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.


2010 ◽  
Vol 22 (1) ◽  
pp. 325
Author(s):  
A. Furugaichi ◽  
M. Hoshina ◽  
J. Ito ◽  
N. Kashiwazaki

Contrary to experimental animals, it is well known that pig oocytes show low developmental competence after IVM, fertilization and culture despite of the attempts to improve the IVM technology. One of the reasons causing such low developmental ability of porcine oocytes seems to be the culture condition, especially the gas phase for IVM because there is a large differences in oxygen tension between in vitro and in vivo conditions. Indeed, our preliminary study revealed that oocytes matured in vivo had larger perivitelline space than oocytes matured in vitro, which could be affected by in vitro culture condition. The present study was conducted to evaluate the effect of oxygen tensions on nuclear maturation, cumulus expansion and glutathione synthesis of porcine oocytes during IVM. COCs at the germinal vesicle stage were collected from ovaries of prepubertal gilts and cultured in modified NCSU37 either under 2, 5, or 20% O2 for 44 h (Group 2%, Group 5%, and Group 20%, respectively). Five percent CO2 was used for all groups. After culture, the cumulus expansion was morphologically evaluated by classification to three grades (Grade 1: excellent [the length of expanded cumulus cells was longer than the diameter of the oocyte], Grade 2: good [the length of expanded cumulus cells was less than the diameter of oocyte], Grade 3: poor [oocyte having partial or single layer of expanded cumulus cells]). All experiments in this study were replicated more than 5 times. Data were analyzed by ANOVA and then shown as mean ± SD%. The rate of Grade 1 in Group 2% (16.8 ± 8.3%, 32/189) was significantly lower than those in Group 5% (68.2 ± 11.2%, 149/228) and Group 20% (78.6 ± 6.9%, 162/201) (P < 0.05). As for rates of Grade 2 and Grade 3, there were no significant differences between the groups. After evaluation of cumulus expansion, cumulus cells were removed and oocytes were stained by aceto-orcein for evaluation of nuclear maturation. The rates of metaphase II-stage oocytes were 41.0 ± 12.4% (86/210), 47.6 ± 20.5% (119/263) and 47.7 ± 12.9% (100/199) in Group 2%, Group 5%, and Group 20%, respectively. There were no significant differences among the groups. In order to clarify the effect of oxygen concentration on cytoplasmic maturation, COCs were cultured for 44 h and glutathione level of the oocytes was measured by 5,5′-dithio-bis-2-nitro-benzonic acid-glutathione disulfide reductase recycling method. Regardless the oxygen concentration, glutathione level was increased from the start of culture (6.2 ± 3.9 pmol/oocyte). But there were no significant differences in the glutathione level among groups. These results suggest that oxygen concentration during IVM could affect cumulus expansion but not nuclear maturation and cytoplasmic glutathione level in pig oocytes. This work was supported in part by the Promotion and Mutual Aid Corporation for Private Schools of Japan, Grant-in-Aid for Matching Fund Subsidy for Private Universities to J.I. and N.K.


2014 ◽  
Vol 1 (3) ◽  
pp. 3-7
Author(s):  
O. Zhukorskyy ◽  
O. Hulay

Aim. To estimate the impact of in vivo secretions of water plantain (Alisma plantago-aquatica) on the popula- tions of pathogenic bacteria Erysipelothrix rhusiopathiae. Methods. The plants were isolated from their natural conditions, the roots were washed from the substrate residues and cultivated in laboratory conditions for 10 days to heal the damage. Then the water was changed; seven days later the selected samples were sterilized using fi lters with 0.2 μm pore diameter. The dilution of water plantain root diffusates in the experimental samples was 1:10–1:10,000. The initial density of E. rhusiopathiae bacteria populations was the same for both experimental and control samples. The estimation of the results was conducted 48 hours later. Results. When the dilution of root diffusates was 1:10, the density of erysipelothrixes in the experimental samples was 11.26 times higher than that of the control, on average, the dilution of 1:100 − 6.16 times higher, 1:1000 – 3.22 times higher, 1:10,000 – 1.81 times higher, respectively. Conclusions. The plants of A. plantago-aquatica species are capable of affecting the populations of E. rhusiopathiae pathogenic bacteria via the secretion of biologically active substances into the environment. The consequences of this interaction are positive for the abovementioned bacteria, which is demon- strated by the increase in the density of their populations in the experiment compared to the control. The intensity of the stimulating effect on the populations of E. rhusiopathiae in the root diffusates of A. plantago-aquatica is re- ciprocally dependent on the degree of their dilution. The investigated impact of water plantain on erysipelothrixes should be related to the topical type of biocenotic connections, the formation of which between the test species in the ecosystems might promote maintaining the potential of natural focus of rabies. Keywords: Alisma plantago-aquatica, in vivo secretions, Erysipelothrix rhusiopathiae, population density, topical type of connections.


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