Protection against reactive oxygen species during mouse preimplantation embryo development: Role of EDTA, oxygen tension, catalase, superoxide dismutase and pyruvate

Abstract

Oxidative damage due to the production of reactive oxygen species (ROS) is one of a number of culture-induced stresses which may compromise preimplantation embryo development in vitro. Ethylenediaminetetraacetic acid (EDTA), reduced oxygen tension, superoxide dismutase (SOD) and catalase (CAT) offer protection against oxidative stress, but few attempts have been made to determine which of these agents, or which combination, is the most effective. In particular, no systematic investigation of their actions and interactions has been made using a multifactorial experimental design. Murine zygotes were cultured in the presence or absence of 10 miccroM EDTA, SOD (100-7,000 U/ml) and CAT (50-100 U/ml) at atmospheric (20%) and reduced (5%) oxygen tensions. Blastocyst formation and hatching rates (at various time points), and cell numbers were recorded, whilst parallel groups of embryos had their consumption of pyruvate, a hydrogen peroxide scavenger, measured. All parameters interacted significantly and affected blastocyst formation, hatching rate and cell numbers but the effect of EDTA was the most pronounced. There were beneficial effects of 5% O2, CAT and SOD, while 20% O2 had a deleterious effect on development. EDTA improved blastocyst formation and hatching rates but paradoxically led to a reduction in cell number. 5% O2 was the next most significant parameter to enhance embryo development and also increased cell numbers. No differences in pyruvate uptake were apparent between the various treatment groups. The results suggest that embryo culture in EDTA-free medium under 5% O2 provides the most practical and physiological conditions for in vitro murine embryo culture.

Short-term exposure to hydrogen peroxide during oocyte maturation improves bovine embryo development

“…A very straightforward hypothesis is that incubation with H 2 O 2 might increase the level of antioxidants in the oocyte and/or cumulus cells with a positive effect on their future development. Increased levels of antioxidants may improve embryo development to the blastocyst stage as demonstrated for catalase (Li et al 1993, Orsi & Leese 2001, GSH (Luvoni et al 1996, Abeydeera et al 1999, de Matos & Furnus 2000, de Matos et al 2002, Ozawa et al 2006, and superoxide dismutase (Li et al 1993, Chun et al 1994 in different species. GSH content at the end of maturation has been identified as a reliable indicator of oocyte viability (Abeydeera et al 1999).…”

The effect of two distinct levels of oxygen concentration on embryo development in a sibling oocyte study

“…In a mice model, Orsi and Leese [21] showed that a 5 % O 2 concentration significantly contributed to enhancing embryo development and also increased cell numbers.…”

Identification of genes regulated by interleukin-1β in human endometrial stromal cells

“…AKR1B1, with superoxide dismutase-2 and metallothioneins, may act to protect cells from unstable reactive radicals and heavy metals implicated in the pathology of a number of organs including endometrium (Kagi 1991, Ishikawa et al 1993, Sies 1993. These toxic compounds and oxygen free radicals may be detrimental to the attachment, implantation and development of the embryo (Orsi & Leese 2001) and AKR1B1 may play a role around the time of implantation to protect the embryo and to create a safe environment for reception of a fertilised ovum. Similarly at menstruation, these proteins may serve to mop up free radicals generated by highly activated leukocytes during tissue necrosis.…”