Article

Osmotic stress induced by sodium chloride, sucrose or trehalose improves cryotolerance and developmental competence of porcine oocytes

Population Genetics and Embryology, Department of Genetics, Faculty of Agricultural Sciences, University of Aarhus, DK-8830 Tjele, Denmark.
Reproduction Fertility and Development (Impact Factor: 2.4). 02/2009; 21(2):338-44. DOI: 10.1071/RD08145
Source: PubMed

ABSTRACT

Exposure of porcine oocytes to increased concentrations of NaCl prior to manipulation has been reported not only to increase cryotolerance after vitrification, but also to improve developmental competence after somatic cell nuclear transfer (SCNT). In the present study we compared the effects of NaCl with those of concentrated solutions of two non-permeable osmotic agents, namely sucrose and trehalose, on the cryotolerance and developmental competence of porcine oocytes. In Experiment 1, porcine in vitro-matured cumulus-oocyte complexes (COCs; n = 1200) were exposed to 588 mOsmol NaCl, sucrose or trehalose solutions for 1 h, allowed to recover for a further 1 h, vitrified, warmed and subjected to parthenogenetic activation. Both Day 2 (where Day 0 is the day of activation) cleavage and Day 7 blastocyst rates were significantly increased after NaCl, sucrose and trehalose osmotic treatments compared with untreated controls (cleavage: 46 +/- 5%, 44 +/- 7%, 45 +/- 4% and 26 +/- 6%, respectively; expanded blastocyst rate: 6 +/- 1%, 6 +/- 2%, 7 +/- 2% and 1 +/- 1%, respectively). In Experiment 2, COCs (n = 2000) were treated with 588 mOsmol NaCl, sucrose or trehalose, then used as recipients for SCNT (Day 0). Cleavage rates on Day 1 did not differ between the NaCl-, sucrose-, trehalose-treated and the untreated control groups (92 +/- 3%, 95 +/- 3%, 92 +/- 2% and 94 +/- 2%, respectively), but blastocyst rates on Day 6 were higher in all treated groups compared with control (64 +/- 2%, 69 +/- 5%, 65 +/- 3% and 47 +/- 4%, respectively). Cell numbers of Day 6 blastocysts were higher in the control and NaCl-treated groups compared with the sucrose- and trehalose-treated groups. In conclusion, treatment of porcine oocytes with osmotic stress improved developmental competence after vitrification combined with parthenogenetic activation, as well as after SCNT.

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    • "For instance it was observed that placing the cells in controlled stress conditions could enhance the consequent stress tolerance during future stresses like cryopreservation [46]. So far, several stressors have been applied to induce mild stress including hydrostatic pressure [28] [45], osmotic stress [30], mechanical stress [36], and ethanol challenge [49]. In all of these studies the purpose was to initiate a protective mechanism in cells. "

    Full-text · Article · Sep 2015 · Cryobiology
    • "For instance it was observed that placing the cells in controlled stress conditions could enhance the consequent stress tolerance during future stresses like cryopreservation [46]. So far, several stressors have been applied to induce mild stress including hydrostatic pressure [28] [45], osmotic stress [30], mechanical stress [36], and ethanol challenge [49]. In all of these studies the purpose was to initiate a protective mechanism in cells. "
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    ABSTRACT: This study was performed to investigate the effect of sub-lethal exposure of bull semen to ethanol on the post-thaw spermatozoa quality. Semen samples (n=24, 6 ejaculates/bull) from 4 Holstein bulls were collected and pooled. Pooled samples were divided into 4 equal parts and each part was frozen after being diluted with Optidyl(®) extender containing 0 (O-E0), 0.03 (O-E3), 0.09 (O-E9) and 0.15 (O-E15)% (v/v) absolute ethanol. Sperm motility and velocity, plasma membrane integrity and functionality, mitochondrial activity, malondialdehyde concentration, and apoptosis status were evaluated after thawing. A higher percentage of total motility was observed in the O-E9 group as compared to the O-E0, O-E3 and O-E15 groups (p<0.05). Also, plasma membrane integrity was higher (p<0.05) in the O-E9 group compared to the O-E3, and O-E15 groups. However, the difference between the O-E9 and O-E0 groups was not significant (p>0.05). In terms of the proportion of sperm abnormality and plasma membrane functionality no differences (p>0.05) were observed between the groups. Our results revealed that malondialdehyde level was lower in ethanol treated (O-E3, O-E9 O-E15) groups compared to the O-E0 group (p<0.05). Furthermore, the percentage of live spermatozoa with active mitochondria was higher in the O-E9 and O-E15 groups compared to the O-E0 and O-E3 groups (p<0.05). The O-E3 and O-E9 groups resulted in the highest and lowest percentage of apoptotic spermatozoa, respectively (p<0.05). The results of this study demonstrate that supplementation of semen extender with sub-lethal concentration of ethanol influences post-thawed bull sperm quality in a dose dependent manner. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Jun 2015 · Cryobiology
    • "However, although these results provide some insight into HP-influenced processes, the underlying molecular mechanism remains elusive. In addition to HP, optimised oxidative (Vandaele et al. 2010) and osmotic (Lin et al. 2009) stress treatments have been shown to enhance the stress tolerance of bovine and porcine oocytes during preimplantation development, suggesting that a generalised, sublethal stress-induced mechanism may be present in mammalian oocytes. Accordingly, the aim of the present study was to analyse the impact of HP treatment using gene expression microarrays during mouse early preimplantation development. "
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    ABSTRACT: The efficiency of various assisted reproductive techniques can be improved by preconditioning the gametes and embryos with sublethal hydrostatic pressure treatment. However, the underlying molecular mechanism responsible for this protective effect remains unknown and requires further investigation. Here, we studied the effect of optimised hydrostatic pressure treatment on the global gene expression of mouse oocytes after embryonic genome activation. Based on a gene expression microarray analysis, a significant effect of treatment was observed in 4-cell embryos derived from treated oocytes, revealing a transcriptional footprint of hydrostatic pressure-affected genes. Functional analysis identified numerous genes involved in protein synthesis that were downregulated in 4-cell embryos in response to hydrostatic pressure treatment, suggesting that regulation of translation has a major role in optimised hydrostatic pressure-induced stress tolerance. We present a comprehensive microarray analysis and further delineate a potential mechanism responsible for the protective effect of hydrostatic pressure treatment.
    No preview · Article · Dec 2014 · Reproduction Fertility and Development
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