scholarly journals The presence of acylated ghrelin duringin vitromaturation of bovine oocytes induces cumulus cell DNA damage and apoptosis, and impairs early embryo development

Zygote ◽  
2017 ◽  
Vol 25 (5) ◽  
pp. 601-611 ◽  
Author(s):  
Matias A. Sirini ◽  
Juan Mateo Anchordoquy ◽  
Juan Patricio Anchordoquy ◽  
Ana M. Pascua ◽  
Noelia Nikoloff ◽  
...  

SummaryThe aim of this study was to investigate the effects of acylated ghrelin supplementation duringin vitromaturation (IVM) of bovine oocytes. IVM medium was supplemented with 20, 40 or 60 pM acylated ghrelin concentrations. Cumulus expansion area and oocyte nuclear maturation were studied as maturation parameters. Cumulus–oocyte complexes (COC) were assessed with the comet, apoptosis and viability assays. Thein vitroeffects of acylated ghrelin on embryo developmental capacity and embryo quality were also evaluated. Results demonstrated that acylated ghrelin did not affect oocyte nuclear maturation and cumulus expansion area. However, it induced cumulus cell (CC) death, apoptosis and DNA damage. The damage increased as a function of the concentration employed. Additionally, the percentages of blastocyst yield, hatching and embryo quality decreased with all acylated ghrelin concentrations tested. Our study highlights the importance of acylated ghrelin in bovine reproduction, suggesting that this metabolic hormone could function as a signal that prevents the progress to reproductive processes.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247518
Author(s):  
Thais Preisser Pontelo ◽  
Mauricio Machaim Franco ◽  
Taynan Stonoga Kawamoto ◽  
Felippe Manoel Costa Caixeta ◽  
Ligiane de Oliveira Leme ◽  
...  

This study aimed to evaluate the effect of scriptaid during pre-maturation (PIVM) and/or maturation (IVM) on developmental competence of bovine oocytes. Cumulus-oocyte complexes (COCs) were submitted to PIVM for 6 h in the presence or absence of scriptaid. COCs were distributed into five groups: T1-IVM for 22 h, T2-PIVM for 6 h and IVM for 22 h, T3-PIVM with scriptaid for 6 h and IVM for 22 h, T4-PIVM for 6 h and IVM with scriptaid for 22 h, and T5-PIVM with scriptaid for 6 h and IVM with scriptaid for 22 h. Nuclear maturation, gene expression, cumulus cells (CCs) expansion, and embryo development and quality were evaluated. At the end of maturation, all groups presented the majority of oocytes in MII (P>0.05). Only HAT1 gene was differentially expressed (P<0.01) in oocytes with different treatments. Regarding embryo development at D7, T4 (23%) and T5 (18%) had lower blastocyst rate (P<0.05) than the other treatments (T1 = 35%, T2 = 37% and T3 = 32%). No effect was observed when scriptaid in PIVM was used in less competent oocytes (P>0.05). In conclusion, presence of scriptaid in PIVM and/or IVM did not improve developmental competence or embryo quality.



Zygote ◽  
2016 ◽  
Vol 24 (6) ◽  
pp. 869-879 ◽  
Author(s):  
D.E. Rosa ◽  
J.M. Anchordoquy ◽  
J.P. Anchordoquy ◽  
M.A. Sirini ◽  
J.A. Testa ◽  
...  

SummaryThe aim of this study was to investigate the influence of copper (Cu) duringin vitromaturation (IVM) on apoptosis and DNA integrity of cumulus cells (CC); and oocyte viability. Also, the role of CC in the transport of Cu during IVM was evaluated on oocyte developmental capacity. Damage of DNA was higher in CC matured without Cu (0 µg/dl Cu,P< 0.01) with respect to cells treated with Cu for cumulus–oocyte complexes (COCs) exposed to 0, 20, 40, or 60 µg/dl Cu). The percentage of apoptotic cells was higher in CC matured without Cu than in CC matured with Cu. Cumulus expansion and viability of CC did not show differences in COC treated with 0, 20, 40, or 60 µg/dl Cu during IVM. Afterin vitrofertilization (IVF), cleavage rates were higher in COC and DO + CC (denuded oocytes + CC) with or without Cu than in DO. Independently of CC presence (COC, DO + CC or DO) the blastocyst rates were higher when 60 µg/dl Cu was added to IVM medium compared to medium alone. These results indicate that Cu supplementation to IVM medium: (i) decreased DNA damage and apoptosis in CC; (ii) did not modify oocyte viability and cumulus expansion; and (iii) improved subsequent embryo development up to blastocyst stage regardless of CC presence during IVM.



2006 ◽  
Vol 18 (2) ◽  
pp. 272
Author(s):  
K. Kananen-Anttila ◽  
M. Eronen ◽  
J. Matilainen ◽  
M. Kallio ◽  
J. Peippo ◽  
...  

We have studied the effect of suppressed IVM on the developmental competence of bovine oocytes, aiming at elucidating the importance of cytoplasmic maturation in fertilization and embryo development. Six replicates of abattoir-derived oocytes were randomly divided into three IVM groups. Control (n = 950): TCM-199 with glutamax-I (Gibco, Grand Island, NY, USA), 0.25 mM Na-pyruvate, 100 IU mL−1 penicillin and 100 μg mL−1 streptomycin, 50 ng mL−1 FSH, and 10% fetal bovine serum (FBS) (Gibco); Serum+FSH-free (n = 944): same as control but without FSH and FBS; α-amanitin (n = 977): same as control but with 10 μg mL−1 α-amanitin. Nuclear maturation of oocytes was studied 24 h after the onset of IVM, the formation of sperm aster structure 10 hours post-insemination (hpi) and the formation of pronuclei 20 hpi. Sperm aster was visualized with β-tubulin antibody (modified from Navara et al. 1999 Dev. Biol. 162, 29–40). Presumptive zygotes were cultured until Day 7 in modified SOFaaci + 4 mg mL−1 fatty acid-free BSA in 5% O2. Cumulus cell expansion was seen only in the control group. The results of nuclear maturation, fertilization, and embryo development are summarized in Table 1. Serum and FSH deprivation did not have a statistically significant effect on the parameters studied (vs. control). α-amanitin exposure during IVM reduced nuclear maturation, fertilization, and Day 3 embryo cleavage vs. control, and resulted in total blockage of Day 7 blastocyst development. The treatment groups had significantly smaller mean diameters of male pronuclei (control: 14 ± 0.6 μ­m; serum+FSH-free: 12 ± 0.5 μ­m, P < 0.05; α-amanitin: 10 ± 0.6 μ­m, P < 0.001) and sperm asters (control: 86 ± 4 μ­m; serum+FSH-free: 82 ± 4 μ­m, P < 0.01; α-amanitin: 49 ± 7 μm, P < 0.001) (nonparametric Kruskall Wallis and Mann-Whitney U tests) vs. control group. Despite reduction in pronucleus and sperm aster diameter, serum and FSH deprivation during IVM did not affect in vitro developmental competence of bovine oocytes, suggesting a need for re-evaluation of the components of IVM. α-Amanitin exposure in IVM disturbed nuclear maturation, fertilization, and embryo development, indicating the essence of early transcription. Table 1. Average percentages ± (n) for nuclear maturation, fertilization (min two pronuclei), embryo cleavage, and blastocyst development



2016 ◽  
Vol 28 (2) ◽  
pp. 222
Author(s):  
M. S. Araujo ◽  
M. D. Guastali ◽  
A. C. S. Castilho ◽  
F. Landim-Alvarenga

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.



Zygote ◽  
2010 ◽  
Vol 19 (2) ◽  
pp. 107-116 ◽  
Author(s):  
Letícia Siqueira Sá Barretto ◽  
Viviane Sgobbi Dias Caiado Castro ◽  
Joaquim Mansano Garcia ◽  
Gisele Zoccal Mingoti

SummaryAiming to improve the developmental competence of bovine oocytes during meiotic block, this study evaluated the effects of a serum replacer (Knockout SR®) and hormones (gonadotropins and estradiol) supplementation of prematuration medium (TCM119 with 0.5 mM IBMX [IBMX group] or 25 μM roscovitine [ROSC group]) on the kinetics of oocyte nuclear maturation and embryo development. Most IBMX and ROSC oocytes prematured for 8 h culture remained in the GV stage (70.3% and 73.1%, respectively; p > 0.05) similar to Control 8 h (63.5%) and to control immature oocytes (Control 0 h, 92.5%). After prematuration for 16 h, no oocytes remained in the GV stage at similar rates to those recently aspirated (p < 0.05); GV rates in ROSC (32.4%) were higher (p < 0.05) than in the Control 16 h group (8.6%), but similar (p > 0.05) to IBMX (9.7%). After in vitro maturation (IMV) for 24 h, metaphase II (MII) rates for oocytes prematured during 8 h were similar (p > 0.05) between control and treatments (65.0–71.7%). Similarly, MII rates oocytes prematured during 16 h were similar (p > 0.05) between all groups (45.9–60.4%). Cleavage rates (67.8–78.2%), embryonic development in day-7 (25.0–35.6%) and hatching rates in day-8 (2.5–11.3%) oocytes blocked during 8 h were similar for all groups (p > 0.05). Results indicate that addition of Knockout SR® and hormones to meiotic block culture with IBMX and roscovitine negatively affected meiotic arrest, but did not impair oocyte nuclear maturation and acquisition of developmental competence.



2005 ◽  
Vol 17 (4) ◽  
pp. 407 ◽  
Author(s):  
Melanie L. Sutton-McDowall ◽  
Robert B. Gilchrist ◽  
Jeremy G. Thompson

In vitro oocyte maturation (IVM) culture conditions have been relatively unchanged over the past few decades and remain suboptimal. In contrast, studies of the in vivo environment have led to significant improvements to in vitro embryo culture technologies. The aim of the present study was to determine the effect of maturing bovine cumulus–oocyte complexes (COCs) in medium based on the composition of bovine follicular fluid (Bovine VitroMat; Cook Australia, Eight Mile Plain, Qld, Australia). In particular, the effect of different glucose concentrations and glucosamine supplementation on meiotic maturation was determined. Culturing COCs in the presence of gonadotrophins in Bovine VitroMat, containing either physiological glucose concentrations (2.3 mm) or 5.6 mm (equivalent to levels in Tissue Culture Medium 199 (TCM199)) supplemented with glucosamine resulted in comparable cumulus expansion to COCs cultured in TCM199 plus gonadotrophins. However, nuclear maturation was 1.3-fold lower in Bovine VitroMat cultures containing 2.3 mm glucose compared with 5.6 mm glucose and this effect was independent of glucosamine supplementation. Investigations into the effects of different glucose concentrations and gonadotrophin supplementation during the initial 6 h of maturation demonstrated that COCs cultured in Bovine VitroMat with 5.6 mm glucose without gonadotrophins had a twofold acceleration of the rate of meiotic resumption, yet the rate of polar body formation was decreased by approximately 20% compared with cultures in 2.3 mm glucose and TCM199. However, this effect was not seen when COCs were cultured for the initial 16 h in Bovine VitroMat + 5.6 mm minus gonadotrophins or in Bovine VitroMat + 2.3 mm glucose ± gonadotrophins. These data demonstrate that glucose concentrations and the timing of the introduction of gonadotrophin during IVM have variable effects on nuclear maturation. Manipulation of glucose concentrations may be a mechanism to influence oocyte meiotic progression and may lead to the development of improved IVM systems, allowing for an increased developmental capacity of bovine oocytes.



2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Á Martíne. Moro ◽  
I Lamas-Toranzo ◽  
L González-Brusi ◽  
A Pérez-Gómez ◽  
P Bermejo-Álvarez

Abstract Study question Does cumulus cell mtDNA content correlate with oocyte developmental potential in the bovine model? Summary answer The relative amount of mtDNA content did not vary significantly in oocytes showing different developmental outcomes following IVF What is known already Cumulus cells are closely connected to the oocyte through transzonal projections, serving essential metabolic functions during folliculogenesis. These oocyte-supporting cells are removed and discarded prior to ICSI, thereby constituting an interesting biological material on which to perform molecular analysis aimed to predict oocyte developmental competence. Previous studies have positively associated oocytés mtDNA content with developmental potential in both animal models and women. However, it remains debatable whether mtDNA content in cumulus cells could be used as a proxy to infer oocyte developmental potential. Study design, size, duration Bovine cumulus cells were allocated into three groups according to the developmental potential of the oocyte: 1) oocytes developing to blastocysts following IVF (Bl+Cl+), 2) oocytes cleaving following IVF but arresting their development prior to the blastocyst stage (Bl-Cl+), and 3) oocytes not cleaving following IVF (Bl-Cl-). Relative mtDNA content was analysed in 40 samples/group, each composed by the cumulus cells from one cumulus-oocyte complex (COC). Participants/materials, setting, methods Bovine cumulus-oocyte complexes were obtained from slaughtered cattle and individually matured in vitro (IVM). Following IVM, cumulus cells were removed by hyaluronidase treatment, pelleted, snap frozen in liquid nitrogen and stored at –80 ºC until analysis. Cumulus-free oocytes were fertilized and cultured in vitro individually and development was recorded for each oocyte. Relative mtDNA abundance was determined by qPCR, amplifying a mtDNA sequence (COX1) and a chromosomal sequence (PPIA). Statistical differences were tested by ANOVA. Main results and the role of chance Relative mtDNA abundance did not differ significantly (ANOVA p &gt; 0.05) between the three groups exhibiting different developmental potential (1±0.06 vs. 1.19±0.05 vs. 1.11±0.05, for Bl+Cl+ vs. Bl-Cl+ vs. Bl-Cl-, mean±s.e.m.). Limitations, reasons for caution Experiments were conducted in the bovine model. Although bovine folliculogenesis, monoovulatory ovulation and early embryo development exhibit considerable similarities with that of humans, caution should be taken when extrapolating these data to humans. Wider implications of the findings: The use of molecular markers for oocyte developmental potential in cumulus cells could be used to enhance success rates following single-embryo transfer. Unfortunately, mtDNA in cumulus cells was not found to be a good proxy for oocyte quality. Trial registration number Not applicable



Zygote ◽  
2002 ◽  
Vol 10 (4) ◽  
pp. 349-354 ◽  
Author(s):  
Yong-Hai Li ◽  
Rui-Hua Liu ◽  
Li-Hong Jiao ◽  
Wei-Hua Wang

This study was conducted to examine the effect of epidermal growth factor (EGF) and 17β-estradiol (E2) on nuclear and cytoplasmic (male pronuclear formation and early embryo development) maturation of porcine oocytes. Oocytes were aspirated from antral follicles and cultured in modified TCM-199 medium supplemented with 0.57 mM cysteine, 10 IU/ml eCG, 10 IU/ml hCG, with or without EGF and/or E2. In vitro fertilisation of matured oocytes was performed in a modified Tris-buffered medium (mTBM) with frozen-thawed ejaculated spermatozoa. Oocytes were transferred to NCSU-23 supplemented with 0.4% bovine serum albumin at 6 h after in vitro fertilisation. Significantly higher (p < 0.05) rates of nuclear maturation, pronuclear formation and cleavage (91.7%, 65.2% and 37.3%, respectively) were observed when oocytes were cultured in the medium containing both EGF (10 ng/ml) and E2 (1 μg/ml) than in the medium supplemented with either EGF or E2 or without both. Intracellular glutathione concentration in the oocytes cultured in the medium containing both E2 and EGF was also significantly higher (12.1 pmol per oocyte) than that of oocytes cultured in the medium with E2 or EGF alone or without both. These findings suggested that EGF and E2 have a synergestic effect on both nuclear and cytoplasmic maturation of porcine oocytes.



Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 24-31 ◽  
Author(s):  
Rosiara Rosária Dias Maziero ◽  
Carlos Renato de Freitas Guaitolini ◽  
Daniela Martins Paschoal ◽  
André Maciel Crespilho ◽  
Bianca Andriolo Monteiro ◽  
...  

SummaryThis study evaluated the effects of oocyte meiosis inhibitors roscovitine (ROS) and butyrolactone I (BL-I) on in vitro production of bovine embryos. Bovine oocytes were maintained in pre in vitro maturation (pre-IVM) with 25 µM ROS or 100 µM BL-I for 24 h to delay meiosis and for 24 h in in vitro maturation (IVM). Following this treatment, the nuclear maturation index was evaluated. All embryos degenerated following this procedure. In the second set of experiments, oocytes were maintained for 6 or 12 h in pre-IVM with the following three treatments: ROS (25 µM or 12.5 µM), BL-I (100 µM or 50 µM) or a combination of both drugs (6.25 µM ROS and 12.5 µM BL-I). Oocytes were cultivated for 18 or 12 h in IVM. When a meiosis-inducing agent was used during pre-IVM for 24 h, more degenerated oocytes were observed at the end of the IVM period. This effect decreased when the meiotic blocking period was reduced to 6 or 12 h. No significant differences were observed in the blastocyst production rate of oocytes in pre-IVM for 6 h with ROS, BL-I, or ROS + BL-I compared with that of the control group (P > 0.05). However, inhibition of oocytes for 12 h resulted in decreased embryo production compared with that in the controls (P < 0.05). There was no difference in the post-vitrification embryo re-expansion rate between the study groups, showing that the meiotic inhibition for 6 or 12 h did not alter the embryo cryopreservation process.



Author(s):  
Ales Sobek ◽  
Emil Tkadlec ◽  
Eva Klaskova ◽  
Martin Prochazka

Abstract The aim of this study was to evaluate if cytoplasmic transfer can improve fertilization and embryo quality of women with oocytes of low quality. During ICSI, 10–15% of the cytoplasm from a fresh or frozen young donor oocyte was added to the recipient oocyte. According to the embryo quality, we defined group A as patients in which the best embryo was evident after cytoplasmic transfer and group B as patients in which the best embryo was evident after a simple ICSI. We investigated in the period of 2002–2018, 125 in vitro fertilization cycles involving 1011 fertilized oocytes. Five hundred fifty-seven sibling oocytes were fertilized using ICSI only and 454 oocytes with cytoplasmic transfer. Fertilization rates of oocytes were 67.2% in the cytoplasmic transfer and 53.5% in the ICSI groups (P < 0.001). A reduction in fertilization rate was observed with increased women age in the ICSI but not in the cytoplasmic transfer groups. The best embryo quality was found after cytoplasmic transfer in 78 cycles (62.4%) and without cytoplasmic transfer in 40 cycles (32%, P < 0.001). No significant differences were detected between the age, hormonal levels, dose of stimulation drugs, number of transferred embryos, pregnancy rate and abortion rate between A and B groups. Cytoplasmic transfer improves fertilization rates and early embryo development in humans with low oocyte quality. All 28 children resulting from cytoplasmic transfer are healthy.



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