Effect of supplementation of medium with Bauhinia forficata recombinant lectins on expression of oxidative stress genes during in vitro maturation of bovine oocytes

This study was conducted to explore the effect of energy substrates in the culture medium during in vitro maturation of bovine oocytes. A modified TCM199 medium (M-7528) was used to mature bovine oocytes in vitro. Oocytes were supplemented with different pyruvate (0.1, 0.2, 0.4 mM) and glucose (1.5, 5.6, 20.0 mM) concentrations for 48 hours at 38.5 °C under 5% CO2 atmosphere with 95% humidity. Their maturity was checked at 24 and 48 hours. After 48 hours, the denuded oocytes were stained with fluorescent dye JC-1 and avidin-FITC. Fluorescent dye JC-1 is a membrane permeable to the cell and would indicates membrane activity or its organization. Fluorescence intensity of avidin-FITC determination using corrected total cell fluorescence (CTCF) expressed oxidative stress level. There is a significant contribution of energy substrates towards oocyte maturation. Pyruvate at 0.2 mM produced mature oocytes with a diameter of ≥ 120 μm, promoted oocytes maturation to metaphase II (MII) stage faster and reduced cell’s oxidative stress levels. In comparison, 5.6 mM glucose is the optimum concentration for glucose to reduce cell stress level. Unfortunately, this concentration only produced mature oocytes with a small diameter of up to 116 μm. All changes were significant at the level of p < 0.05. As a conclusion, pyruvate at 0.2 mM is the optimum concentration for in vitro maturation after taking cell’s stress level into consideration.

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Effects of melatonin on production of reactive oxygen species and developmental competence of bovine oocytes exposed to heat shock and oxidative stress during in vitro maturation CORRIGENDUM

Zygote ◽

10.1017/s0967199419000479 ◽

2019 ◽

Vol 27 (4) ◽

pp. 262-262

Author(s):

Fernanda de Castro Cavallari ◽

Cláudia Lima Verde Leal ◽

Roth Zvi ◽

Peter J. Hansen

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Heat Shock ◽

In Vitro Maturation ◽

Reactive Oxygen ◽

Developmental Competence ◽

Oxygen Species ◽

Bovine Oocytes ◽

And Oxidative Stress

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254 EFFECTS OF OXYGEN TENSION AND OOCYTE DENSITY DURING IN VITRO MATURATION ON THE LEVELS OF REACTIVE OXYGEN SPECIES IN BOVINE OOCYTES AND MATURATION MEDIUM

Reproduction Fertility and Development ◽

10.1071/rdv25n1ab254 ◽

2013 ◽

Vol 25 (1) ◽

pp. 274

Author(s):

A. B. Giotto ◽

A. C. G. Guimarães ◽

C. G. M. Gonçalves ◽

N. P. Folchini ◽

C. I. I. U. F. Machado ◽

...

Keyword(s):

Oxidative Stress ◽

Oxygen Tension ◽

In Vitro Maturation ◽

Early Embryo ◽

Ros Production ◽

Oxygen Species ◽

Early Embryo Development ◽

Treatment Groups ◽

Bovine Oocytes

The reactive oxygen species (ROS) produced by animal cells and at physiological levels are responsible for several cellular functions. However, when there is an imbalance between ROS production and the antioxidant system in the cell, oxidative stress occurs and causes severe cell damage. In oocytes, ROS can affect the dynamics of maturation and early embryo development processes. Oxygen tension and the density of oocytes by medium volume during in vitro maturation (IVM) can influence ROS production. The aim of this study was to evaluate the influence of the association between oxygen tension (5 or 20%) and different oocyte densities during IVM (1 : 10 or 1 : 20 oocytes µL–1 of medium) on the ROS levels in oocytes and medium. Bovine oocytes (n = 420) were obtained from slaughterhouse ovaries by aspiration of 2- to 8-mm follicles. Quality I and II oocytes (De Loss et al. 1989 Gamete Res. 24, 197–204) were homogeneously distributed into groups of 15 oocytes per treatment: Treatment (T) 1 = 1 : 10 in 5% of O2; T2 = 1 : 10 in 20% of O2; T3 = 1 : 20 in 5% of O2; and T4 = 1 : 20 in 20% of O2. The oocytes were matured in TCM-199 supplemented with 10% oestrous mare serum, 100 µg mL–1 of epidermal growth factor, 50 µg mL–1 of LH, 5 µg mL–1 of FSH, and 22 µg mL–1 of pyruvate for 22 to 24 h at 39°C, in 5% CO2 and saturated humidity. To assay ROS production, denuded oocytes and 60-µL samples of IVM medium were evaluated by the spectrofluorometric method with 2′7′-dichlorofluorescein-diacetate, in which the fluorescence intensity emission was considered an indicator of ROS production and measured by a spectrofluorophotometer. The ROS production in oocytes and in IVM medium was expressed as units of fluorescence (UF); data were analysed by ANOVA and Duncan’s test with a 5% level of significance. Seven replications were performed. In treatment groups T1 and T3, the ROS production in oocytes was higher (P < 0.05) than in oocytes of treatment groups T2 and T4 (13.53 and 18.78 UF v. 7.92 and 6.15 UF, respectively). The ROS production in IVM medium was higher in the T1 (23.86 UF) and T2 (24.12 UF) treatment groups than in the T3 (18.78 UF) and T4 (18.57 UF) treatment groups. These results suggest an increase in ROS production in IVM oocytes under a 5% O2 atmosphere in relation to a 20% O2 atmosphere, irrespective of the oocyte density by volume of IVM medium. On the other hand, the accumulation of ROS in IVM medium seemed higher when the oocyte density was 1 oocyte to 10 µL of IVM medium, independent of the oxygen tension used. A higher level of ROS in 5% O2 tension may be caused by competition for O2 between oocyte and cumulus cells, causing a reduction in O2 levels and changing the availability of O2 to energy generation in oocytes and consequently increasing ROS generation. In this respect, 5% O2 during IVM may contribute to the onset of oxidative stress in oocytes, which may compromise fertilization and early embryo development. Further research is necessary to clarify esterase activity in oocytes and the addition of exogenous peroxidase to validate the assay. Financial support: FAPERGS (1011575) and CNPq (501763/2009).

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Effect of melatonin in culture medium on in vitro maturation and DNA integrity of bovine oocytes

Journal of Veterinary Medical Research ◽

10.21608/jvmr.2011.77662 ◽

2011 ◽

Vol 21 (1) ◽

pp. 44-50

Author(s):

Saadia A. Ali ◽

Nermeen A. Helmy ◽

B. R. Abdel-Halim

Keyword(s):

In Vitro Maturation ◽

Culture Medium ◽

Dna Integrity ◽

Bovine Oocytes

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Effect of oxygen and glucose availability during in vitro maturation of bovine oocytes on development and gene expression

Journal of Assisted Reproduction and Genetics ◽

10.1007/s10815-021-02218-w ◽

2021 ◽

Author(s):

Annie Whitty ◽

Karen L. Kind ◽

Kylie R. Dunning ◽

Jeremy G. Thompson

Keyword(s):

Gene Expression ◽

In Vitro Maturation ◽

Effect Of Oxygen ◽

Bovine Oocytes ◽

Glucose Availability

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Melatonin Promotes In Vitro Maturation of Vitrified-Warmed Mouse Germinal Vesicle Oocytes, Potentially by Reducing Oxidative Stress through the Nrf2 Pathway

Animals ◽

10.3390/ani11082324 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2324

Author(s):

Shichao Guo ◽

Jinyu Yang ◽

Jianpeng Qin ◽

Izhar Hyder Qazi ◽

Bo Pan ◽

...

Keyword(s):

Oxidative Stress ◽

Signaling Pathway ◽

In Vitro Maturation ◽

Germinal Vesicle ◽

Melatonin Receptors ◽

Development Rates ◽

Nrf2 Signaling Pathway ◽

Mouse Gv Oocytes ◽

Intracellular Oxidative Stress

Previously it was reported that melatonin could mitigate oxidative stress caused by oocyte cryopreservation; however, the underlying molecular mechanisms which cause this remain unclear. The objective was to explore whether melatonin could reduce oxidative stress during in vitro maturation of vitrified-warmed mouse germinal vesicle (GV) oocytes through the Nrf2 signaling pathway or its receptors. During in vitro maturation of vitrified-warmed mouse GV oocytes, there were decreases (p < 0.05) in the development rates of metaphase I (MI) oocytes and metaphase II (MII) and spindle morphology grades; increases (p < 0.05) in the reactive oxygen species (ROS) levels; and decreases (p < 0.05) in expressions of Nrf2 signaling pathway-related genes (Nrf2, SOD1) and proteins (Nrf2, HO-1). However, adding 10−7 mol/L melatonin to both the warming solution and maturation solutions improved (p < 0.05) these indicators. When the Nrf2 protein was specifically inhibited by Brusatol, melatonin did not increase development rates, spindle morphology grades, genes, or protein expressions, nor did it reduce vitrification-induced intracellular oxidative stress in GV oocytes during in vitro maturation. In addition, when melatonin receptors were inhibited by luzindole, the ability of melatonin to scavenge intracellular ROS was decreased, and the expressions of genes (Nrf2, SOD1) and proteins (Nrf2, HO-1) were not restored to control levels. Therefore, we concluded that 10−7 mol/L melatonin acted on the Nrf2 signaling pathway through its receptors to regulate the expression of genes (Nrf2, SOD1) and proteins (Nrf2, HO-1), and mitigate intracellular oxidative stress, thereby enhancing in vitro development of vitrified-warmed mouse GV oocytes.

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