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Cherbourg-Octeville, France

Menezo Y.,Laboratoire Dynabio | Menezo Y.,Laboratoire dEylau | Menezo Y.,College de France | Entezami F.,Laboratoire Dynabio | And 5 more authors.
Zygote | Year: 2014

One of the most important concerns in assisted reproduction (ART), and in particular ICSI, is the quality of sperm DNA. Oxidative stress is one of the major causes of damage to DNA and attempting to reduce generation of DNA damage related to reactive oxygen species (ROS) through consumption of antioxidants is often tempting. However, current antioxidant treatments, given irrespectively of clinically quantified deficiencies, are poorly efficient, potentially detrimental and over-exposure is risky. Here we discuss new treatments in relation to present day concepts on oxidative stress. This discussion includes stimulation of endogenous anti-ROS defense i.e. glutathione synthesis and recycling of homocysteine, the epicentre of multiple ROS-linked pathologies. © 2012 Cambridge University Press. Source


Menezo Y.,Laboratoire dEylau | Menezo Y.,Laboratoire Dynabio | Pluntz L.,Laboratoire dEylau | Chouteau J.,Oriade | And 5 more authors.
Reproductive BioMedicine Online | Year: 2011

Serum and follicular fluid zinc concentrations were investigated in patients undergoing assisted reproductive treatment. No correlation was found between zinc and oestradiol concentrations in serum. At the time of oocyte retrieval, zinc concentrations in follicular fluid were significantly lower than serum concentrations (P < 0.0001). The expression of the two families of zinc transporters, ZnT and ZiP, as well as the metal regulatory transcription factors, MTF1 and 2, and metallothioneins, which are both involved in regulatory aspects of zinc transport, was assayed in cumulus cells and in germinal-vesicle oocytes. Most of the zinc transporters, metallothioneins and metal regulatory transcription factor are expressed in oocytes and not in cumulus cells. This may indicate an important role for zinc, in particular with potential linking to genome stability during early embryonic development. In contrast, cumulus cells seem to be at the end of their life's journey, with weak expression of transcriptional activity linked to cellular housekeeping. © 2011 ALPHA Scientists in Reproductive Medicine and the European Society of Human Reproduction and Embryology. Published by Elsevier Ltd. All rights reserved. Source


Montjean D.,Unilabs | Entezami F.,Laboratoire Dynabio | Lichtblau I.,Unilabs | Belloc S.,Unilabs | And 2 more authors.
Journal of Assisted Reproduction and Genetics | Year: 2012

Purpose: The purpose of this study is to study lipid metabolism in oocytes and embryos that is a neglected parameter in human IVF. Methods: We have tested the total carnitine content (TC) in the follicular fluid of 278 patients (217 non pregnant, 61 pregnant) undergoing IVF. Results: The follicular fluid TC is neither correlated with the circulating estradiol content in serum nor with the outcome the IVF attempt. Carnitine, through the carnitine shuttle, is a major partner in lipid beta oxidation, metabolic pathway involved in the acquisition of oocyte competence. The expression of carnitine synthesis enzymes and lipid beta oxidation was studied in cumulus cells collected at the time of ovum retrieval and in oocyte. Surprisingly the expression for carnitine synthesis is not detectable in oocytes whereas the enzymes involved in lipid beta oxidation are rather strongly expressed. Conclusions: The addition of carnitine in oocyte maturation and embryo culture media should not be overlooked. © 2012 Springer Science+Business Media, LLC. Source


Haouzi D.,Montpellier University Hospital Center | Haouzi D.,French Institute of Health and Medical Research | Haouzi D.,Montpellier University | Bissonnette L.,Montpellier University Hospital Center | And 15 more authors.
BioMed Research International | Year: 2014

The impact of a premature elevation of serum progesterone level, the day of hCG administration in patients under controlled ovarian stimulation during IVF procedure, on human endometrial receptivity is still debated. In the present study, we investigated the endometrial gene expression profile shifts during the prereceptive and receptive secretory stage in patients with normal and elevated serum progesterone level on the day of hCG administration in fifteen patients under stimulated cycles. Then, specific biomarkers of endometrial receptivity in these two groups of patients were tested. Endometrial biopsies were performed on oocyte retrieval day and on day 3 of embryo transfer, respectively, for each patient. Samples were analysed using DNA microarrays and qRT-PCR. The endometrial gene expression shift from the prereceptive to the receptive stage was altered in patients with high serum progesterone level (>1.5 ng/mL) on hCG day, suggesting accelerated endometrial maturation during the periovulation period. This was confirmed by the functional annotation of the differentially expressed genes as it showed downregulation of cell cycle-related genes. Conversely, the profile of endometrial receptivity was comparable in both groups. Premature progesterone rise alters the endometrial gene expression shift between the prereceptive and the receptive stage but does not affect endometrial receptivity. © 2014 Delphine Haouzi et al. Source

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