scholarly journals Effect of enzymatic pro-oxidant and antioxidant systems on bovine oocyte in vitro maturation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sergio Morado ◽  
Stephania Madrid Gaviria ◽  
Gabriel Dalvit ◽  
Pablo Cetica

Abstract The role of reactive oxygen species (ROS) during oocyte in vitro maturation (IVM) is still controversial. Although an increase in ROS production may cause deleterious effects in cells, these reactive species may also act as signaling molecules influencing different cell functions. The aim of this study was to examine the effect of varying endogenous ROS levels during IVM on the process of bovine oocyte maturation. To do so, different enzymatic antioxidant (catalase, or superoxide dismutase + catalase, or diphenyl iodonium) or pro-oxidant systems (xanthine + xanthine oxidase, or xanthine + xanthine oxidase + catalase) were added to the culture medium. ROS levels were determined by 2′,7′-dichlorodihydrofluorescein diacetate stain, nuclear maturation was evaluated by the presence of the metaphase II chromosome configuration at 22h of IVM and cleavage rate was recorded 48hs post- in vitro fertilization. ROS levels were only significantly increased (P<0.05) by the O2 .- generating system (xanthine + xanthine oxidase + catalase), but meiotic maturation rates were significantly lower (P<0.05) in all the evaluated systems compared with the control, except for the diphenyl iodonium group. However, this last group presented a significantly lower (P<0.05) cleavage rate in comparison to the control group. These results indicate that ROS would play an essential role during oocyte maturation, since its increase or decrease beyond a physiological level significantly reduced nuclear or cytoplasmic maturation rates in bovine oocytes.

Zygote ◽  
2014 ◽  
Vol 23 (3) ◽  
pp. 416-425 ◽  
Author(s):  
Yan Yun ◽  
Peng An ◽  
Jing Ning ◽  
Gui-Ming Zhao ◽  
Wen-Lin Yang ◽  
...  

SummaryOocyte-specific linker histone, H1foo, is localized on the oocyte chromosomes during the process of meiotic maturation, and is essential for mouse oocyte maturation. Bovine H1foo has been identified, and its expression profile throughout oocyte maturation and early embryo development has been established. However, it has not been confirmed if H1foo is indispensable during bovine oocyte maturation. Effective siRNAs against H1foo were screened in HeLa cells, and then siRNA was microinjected into bovine oocytes to down-regulate H1foo expression. H1foo overexpression was achieved via mRNA injection. Reverse transcription polymerase chain reaction (RT-PCR) results indicated that H1foo was up-regulated by 200% and down-regulated by 70%. Based on the first polar body extrusion (PB1E) rate, H1foo overexpression apparently promoted meiotic progression. The knockdown of H1foo significantly impaired bovine oocyte maturation compared with H1foo overexpression and control groups (H1foo overexpression = 88.7%, H1foo siRNA = 41.2%, control = 71.2%; P < 0.05). This decrease can be rescued by co-injection of a modified H1foo mRNA that has escaped from the siRNA target. However, the H1e (somatic linker histone) overexpression had no effect on PB1E rate when compared with the control group. Therefore we concluded that H1foo is essential for bovine oocyte maturation and its overexpression stimulates the process.


2010 ◽  
Vol 22 (1) ◽  
pp. 328
Author(s):  
I. La Rosa ◽  
R. Fernandez y Martín ◽  
D. A. Paz ◽  
D. F. Salamone

BMP4 regulates different events during development in all vertebrates and Noggin is one of its powerful inhibitors that blocks BMP4 interaction with its receptors (Groppe et al. 2002). In this work, the effect of these factors on bovine oocyte maturation and subsequent embryo development has been investigated. COCs were aspirated from abattoir ovaries and in vitro-matured for 22 h or 24 h in a 5% CO2 humidified atmosphere at 39°C in TCM containing 0.6% BSA, 2 mM FSH, 10 mM cysteamine, 1% antibiotic and 1% pyruvate, control group (C), plus 100 ng mL-1 of BMP4 (B), or 100 ngmL-1 of Noggin (NOG). Oocytes were stained with Hoechst 33342 and classified by their nuclear stage. Effects on embryo development were investigated for embryos produced by parthenogenic activation (PA) and IVF For PA, denuded oocytes were chemically activated in 5 μM ionomycine for 4 min, and immediately incubated in 1.9 mM of 6-dimethilaminopurine for 3 h. For IVF, frozen-thawed semen was centrifuged and resuspended in Bracket and Oliphant (BO) solution and incubated with 22 h matured COCs for 5 h. Embryos were cultured in CR2 medium free of serum and co-culture. Cleavage and blastocyst formation were registered at Day 2 and 9 respectively. Fischer’s exact test was used and P ≤ 0.05 was considered significant. Nuclear progression was not affected by maturation treatments [% of MII: 79.4(C, n = 102), 72.4 (B, n = 98), 80.9 (NOG, n = 89)]. For PA, both factors significantly increased cleavage rates [%: 51.7 (C, n = 284), 65 (B, n = 186), 62.1 (NOG, n = 198)] while blastocyst rates were not affected [%: 8.8 (C), 7.5 (B), and 8.6 (NOG)]. On the other hand, for IVF, cleavage rate was statistically lower for Noggin group [%: 70.7 (C, n = 140), 71.3 (B, n = 157), 64 (NOG, n = 159)] while blastocyst rates were similar between groups [%: 15.7 (C), 13.4 (B), 14.5 (NOG)]. Any of the added factors affected cell number of the embryos at Day 2. Blastocysts did not differ in the number of cells at Day 9 (Student’s t-test was used) neither for PA [mean ± SD: 100 ± 33 (C, n = 9), 88 ± 14 (B, n = 3) and 68 ± 8,(NOG, n = 3)] nor for IVF [mean ± SD: 90 ± 24 (C, n = 9), 132 ± 18 (B, n =4) and 99 ± 8 (NOG, n = 3)]. It is noticeable that addition of these factors during in vitro maturation showed different effects on subsequent embryo development depending on whether the embryos were PA or IVF. Probably, these responses represent differences in the BMP signaling system between these embryos which could be associated with different imprinting pattern. Further experiments are needed to elucidate clearly the mechanisms implicated. To our knowledge, this is the first work to study BMP4 inhibition during bovine in vitro maturation. To “Merlo” and “Nueva Escocia” Slaughterhouses


2010 ◽  
Vol 22 (1) ◽  
pp. 336 ◽  
Author(s):  
K. S. Viana ◽  
M. C. C. Bussiere ◽  
C. S. Paes de Carvalho ◽  
B. L. Dias ◽  
M. R. Faes ◽  
...  

The aim of this study was to evaluate morphologic and biochemistry alterations caused by the addition of sodium nitroprusside (SNP), a NO donor, on bovine oocyte maturation in vitro. Bovine ovaries were collected at a local abattoir. COC were cultured in TCM-199 with 10% FCS, 0.5 μg mL-1 FSH, 5.0 μg mL-1 LH, and antibiotics. Analysis of variance was conducted and the means were compared by t-test at a level of 5%. Experimental design: (1) evaluation of the oocyte plasma membrane viability and integrity using Annexin V/propidium iodide (PI) and Hoechst 33342/PI staining, respectively; (2) microtubule and microfilament organization, and migration of cortical granules by immunofluorescence; (3) oocyte glutathione content and concentration of NO3-/NO2-using the method of Griess (Ricart-Jane D et al. 2002 Nitric Oxide 6, 178-185) and (4) embryo development. In Experiment 1, the addition of 1 mM SNP caused cellular death in the majority of the oocytes [100%, AnnexinV/PI (+) and 80.7% Hoescht/IP (+)] differing from the control group and the 0.01 mM SNP (P < 0.05). In Experiment 2, the microtubule staining was observed in the cytoplasm in both control group and 0.01 mM SNP; however, the group treated with 1 mM of SNP exhibited clear defects in spindle and chromatin arrangements (P < 0.05). No alterations in microfilaments disposition was observed in the control group and 0.01 mM SNP. However, after the addition of 1 mM, the microfilaments arranged into clusters, and not below of the cortex. Oocytes treated with 1 mM SNP (68.2%) showed total cortical granule migration to the periphery of the ooplasm and were similar to the control group (72.2%) (P > 0.05). Nevertheless, in the group treated with 0.01 mM SNP the total cortical granule migration was greater (86.8%, P < 0.05). In Experiment 3, the glutathione content of oocytes cultured in the presence of 1 mM SNP was lower (4.4p mol) when compared to the control group (5.4p mol) and 0.01 mM SNP (5.5 pmol) (P > 0.05). The concentration of NO in the medium were similar to both control group (6.0 ± 3.0 μM) and treated with 0.01 mM SNP (15.8 ± 1.9 μM), however, the treatment with 1 mM SNP increased 10 times (59.9 ± 12.0 μM; P < 0.05) this concentration. In Experiment 4, cleavage rates and embryo development were similar for groups control and 0.01 mM SNP (P > 0.05). Even so, in the group treated with 0.01 mM there was a greater blastocyst cell number when compared to the control group (256.8 ± 52.5 and 196.9 ± 54.0, respectively-P < 0.05). These results indicate that: (1) the addition of 0.01 mM SNP increased the quality of the oocyte maturation, leading to a higher percentage of cortical granules migration and blastocyst cell numbers, in a different pathway from that of glutathione; (2) the addition of 1 mM of SNP caused a cytotoxic effect, leading to cellular death with loss of viability and integrity of plasma membrane, absence of nuclear maturation/organization of cytoskeleton and reduction of the glutathione content, although with no intervention in the migration of cortical granules.


Author(s):  
Dhesy Kartikasari ◽  
Sri Mulyati ◽  
Suzanita Utama ◽  
Pudji Srianto ◽  
Widjiati Widjiati ◽  
...  

This study aims to evaluate the expression of BAX, BCL-2, and BAX/BCL-2 ratio in maturation media of cow oocytes which supplemented with Urea in vitro because BAX and BCL-2 are the main regulators of apoptosis. A total of 263 oocytes from follicle aspirations originating from ovaries taken from slaughterhouses and were saturated with 3 addition of urea which was divided into three groups. The control group (P0) was control group without the addition of urea, P1 group was added with urea 20 mg/dL, while P2 group was added with urea 40 mg/dL. The results of in vitro oocyte maturation were continued with identification using immunocytochemical staining with the addition of BAX and BCL-2 antibodies. Positive results showed a brownish color on the oocyte and its cumulus. The results of this study indicated that there were significant differences (P0.05) in BAX and BCL-2 expression, although both curves were equally increase. The increase in BCL-2 was more significant than BAX, while the BAX BCL-2 ratio did not show a significant difference (P0.05) in whichthe curve of BAX/BCL-2 ratio was decreased. It can be concluded that the addition of urea does not affect the level of apoptosis.


2010 ◽  
Vol 22 (1) ◽  
pp. 214
Author(s):  
G. L. Rios ◽  
G. G. Kaiser ◽  
N. C. Mucci ◽  
R. H. Alberio

In this study the effect of increasing ethylene glycol (EG) concentrations in the vitrification media (VM) and its relation with oocyte activation and in vitro embryo production were evaluated. Cumulus-oocytes complexes (COC) were matured in vitro for 22 h and then partially denuded by gently pipetting with hyaluronidase, and randomly assigned to 4 treatments: T1 = control group; T2 = COC exposed to 10% EG + 10% DMSO (VM1), 20% EG + 20% DMSO (VM2); T3 = 15% EG + 5% DMSO (VM1), 30% EG + 10% DMSO (VM2); T4 = 20% EG + 0% DMSO (VM1), 40% EG + 0% DMSO (VM2). Exposition to VM1 and VM2 lasted 3 min and 30 s, respectively. After treatment COC were incubated in maturation medium up to 24 h. In Experiment 1 COC were cultured for 24 h in fertilization TALP supplemented with 50 μg mL-1 of heparin, then completely denuded and cultured 24 h in CR1-aa. After this, oocytes were stained with bisbenzimide (Hoechst 33342) and the number of nuclei and cells were recorded. Structures presenting 2 cells or 2 nuclei were considered as activated oocytes. In Experiment 2 matured COC exposed to cryoprotectants as in Experiment 1 were fertilized and cultured for 6 days as previously described (Mucci et al. 2006). Variables analyzed included oocyte activation, cleavage rate at 48 h, and percentage of viable embryos at Day 7. Data were analyzed by PROC GENMOD (SAS Institute Inc., Cary, NC, USA). Activated oocytes percentage did not differ between EG concentrations in VM and were higher (T2, 24.7%, n = 101; T3, 25.0%, n = 96; T4, 30.2%, n = 119) compared with controls (T1, 9.8%, n = 61). In Experiment 2 no differences were found in cleavage rates (T1, 81.9%, n = 68; T2, 87%, n = 67; T3, 85.9%, n = 61; T4, 84.2%, n = 64) and Day 7 percentage of viable embryos (T1, 34.9%, n = 29; T2, 28.6%, n = 22; T3, 26.8%, n = 19; T4, 27.6%, n = 21) in treated COC. The exposition of COC to cryoprotectants per se could trigger oocyte activation in the range of 10 to 40%. Thanks toAdriana Cano (Instituto Nacional de Tecnología Agropecuaria) for contributions in statistical analysis.


Reproduction ◽  
2001 ◽  
pp. 737-744 ◽  
Author(s):  
Z Roth ◽  
A Arav ◽  
A Bor ◽  
Y Zeron ◽  
R Braw-Tal ◽  
...  

The fertility of dairy cows decreases during the summer and remains low during the cooler autumn although the animals are no longer under heat stress. The aim of this study was to characterize a delayed effect of summer heat stress on oocyte quality in the autumn and to improve oocyte quality by enhanced removal of follicles damaged during the previous summer. Lactating cows (n = 16) were subjected to heat stress during the summer. In autumn, ovarian follicles (3-7 mm in diameter) were aspirated by an ultrasound-guided procedure during four consecutive oestrous cycles. Follicles were aspirated from control cows on day 4 and from treated cows on days 4, 7, 11 and 15 of each oestrous cycle. All cows received PGF(2alpha) and GnRH injections on days 19 and 21, respectively, and maintained cyclicity, as indicated by plasma progesterone concentrations. On day 4 of each cycle, the oocytes recovered were examined morphologically, matured and activated in vitro, and cultured for 8 days. In cycle 1 (early October) both groups showed low percentages of grade 1 oocytes, cleavage, four- and eight-cell embryos, morulae and parthenogenetic blastocysts. Subsequently, the number of grade 1 oocytes increased earlier (cycle 2) in treated than in control cows (cycle 3; P < 0.05). The cleavage rate in the control group remained relatively low throughout (32-58%), whereas in the treated group it increased from 40% (cycle 1) to 75% (cycles 3 and 4; P < 0.05). The number at each stage of embryo development increased slightly but remained low throughout in the control group, whereas in the treated group significant (P < 0.05) increases of all stages were observed in cycles 3 and 4. The results show a delayed effect of summer heat stress on oocyte quality and embryo development in the autumn. Enhanced removal of the impaired cohort of follicles led to earlier emergence of healthy follicles and high quality oocytes in the autumn.


Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1272 ◽  
Author(s):  
Muhammad Idrees ◽  
Lianguang Xu ◽  
Seok-Hwan Song ◽  
Myeong-Don Joo ◽  
Kyeong-Lim Lee ◽  
...  

This study was aimed to investigate the role of SHP2 (Src-homology-2-containing phosphotyrosine phosphatase) in intricate signaling networks invoked by bovine oocyte to achieve maturation and blastocyst development. PTPN11 (Protein Tyrosine Phosphatase, non-receptor type 11) encoding protein SHP2, a positive transducer of RTKs (Receptor Tyrosine Kinases) and cytokine receptors, can play a significant role in bovine oocyte maturation and embryo development, but this phenomenon has not yet been explored. Here, we used different growth factors, cytokines, selective activator, and a specific inhibitor of SHP2 to ascertain its role in bovine oocyte developmental stages in vitro. We found that SHP2 became activated by growth factors and cytokines treatment and was highly involved in the activation of oocyte maturation and embryo development pathways. Activation of SHP2 triggered MAPK (mitogen-activated protein kinases) and PI3K/AKT (Phosphoinositide 3-kinase/Protein kinase B) signaling cascades, which is not only important for GVBD (germinal vesical breakdown) induction but also for maternal mRNA translation. Inhibition of phosphatase activity of SHP2 with PHPS1 (Phenylhydrazonopyrazolone sulfonate 1) reduced oocytes maturation as well as bovine blastocyst ICM (inner cell mass) volume. Supplementation of LIF (Leukemia Inhibitory Factor) to embryos showed an unconventional direct relation between p-SHP2 and p-STAT3 (Signal transducer and activator of transcription 3) for blastocyst ICM development. Other than growth factors and cytokines, cisplatin was used to activate SHP2. Cisplatin activated SHP2 modulate growth factors effect and combine treatment significantly enhanced quality and rate of developed blastocysts.


2005 ◽  
Vol 17 (2) ◽  
pp. 190
Author(s):  
W.C. Chang ◽  
J. Xu ◽  
S. Jiang ◽  
X.C. Tian ◽  
X. Yang ◽  
...  

The aim of this experiment was to determine the effect of the sucrose concentration (0 to 0.33 M) in the dilution medium on the viability, fertilizability, and development of vitrified bovine oocytes. Bovine oocyte-cumulus complexes were collected from slaughterhouse ovaries and in vitro-matured as reported previously. After 24-h maturation in TCM199-based medium under 5% CO2 humidified air at 39°C, these were exposed to hyaluronidase and carefully pipetted to remove all except the 3–5 innermost layers of cumulus. Oocytes were put into the pre-equilibration medium for 3 min and then into vitrification solution containing HEPES-buffered TCM199 supplemented with 20% FBS, ethylene glycol, and dimethylsulphoxide for 25–30 s; they were then vitrified by modified solid surface vitrification (Dinnyes et al. 2000 Biol. Reprod. 63, 513–518).The oocytes were warmed at 39°C by placing them in holding medium with 0, 0.08, 0.17, 0.25, or 0.33 M sucrose. Non-vitrified oocytes were used as controls. Oocytes were inseminated 30 min after warming, and the presumptive zygotes were cultured in CR1-aa medium supplemented with 6 mg/mL BSA at 39°C in a humidified atmosphere of 5% CO2, 5% O2, and 90% N2 for eight days. Data were analyzed by one-way ANOVA. As shown in Table 1, there was no significant difference in survival rate (P > 0.05) of the vitrified oocytes that were placed in dilution solution containing 0.17, 0.25, or 0.33 M sucrose and the non-treated controls. On Day 2 (fertilized on Day 0), cleavage to the 8-cell stage was similar for the 0.17, 0.25, and 0.33 M dilution groups, but the rates for all three were significantly lower (P < 0.05) than for the control group. The blastocyst rate on Day 8 was significantly higher for the 0.25 M group than for any other experimental group but still significantly lower than for the control. In conclusion, this study suggests that with this vitrification/warming procedure the optimum concentration of sucrose in the dilution solution is 0.25 M. Table 1. Oocyte survival after vitrification/warming and subsequent embryo development The authors would like to thank Ms Colleen Shaffer for the preparation of bovine oocytes.


1989 ◽  
Vol 27 ◽  
pp. 39 ◽  
Author(s):  
P.M.M. Kastrop ◽  
M.M. Bevers ◽  
O.H.J. Destrée ◽  
Th.A.M. Kruip

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