Le Blanc-Mesnil, France
Le Blanc-Mesnil, France

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Frainais C.,Laboratoire dHistologie embryologie | Frainais C.,Laboratoire Clement | Vialard F.,Laboratoire Of Biologie Of La Reproduction Et Of Cytogene Tique Chi Poissy | Rougier N.,Laboratoire dHistologie embryologie | And 7 more authors.
Journal of Assisted Reproduction and Genetics | Year: 2010

Introduction: According french legislation, sperm freezing/thawing procedures are used to prevent ART contaminations in couple with HIV-1 infected men. We determined sperm nuclear fragmentation rate before and after selection and freezing/thawing in HIV-1 14 patients. Methods: Two groups of patients were studied: 20 control patients with normal sperm (group 1) and without viral infection and 20 fertile treated HIV-1 patients (group 2). DNA fragmentation was evaluated using terminal uridine nick end labeling, before and after gradient selection, and after cryopreservation and thawing procedures. Results: DNA fragmentation rates in fresh semen were increased in HIV patients (6.38% vs 3.39%) (p<0.05) compared with control patients. After sperm migration, fragmentation rates were significantly lower (p<0.0001) in the two groups compared with fresh sperm rates. After freezing/thawing, values were similar to those of fresh semen with an increased rate (p<0.01) for HIV-1 patients, with respectively 3.40% and 5.18% rates in control and infected patients. HIV-1-infected patients treated by antiretroviral therapy showed a significant increase in sperm DNA fragmentation in fresh sperm and also after freezing/thawing procedures, but these two fragmentation rates were not significantly different. Conclusion: So, freezing/thawing procedures do not seem to impair sperm DNA and preserve probability of conception for couples with HIV-1 infected men. © 2010 Springer Science+Business Media, LLC.


Gurgan T.,Hacettepe University | Montjean D.,Service de Medecine et Biologie de la Reproduction | Demirol A.,Gurgan Clinic | Menezo Y.J.R.,Laboratoire Clement
Journal of Assisted Reproduction and Genetics | Year: 2014

FSH is a key hormone in the regulation of follicular development. Together with the EGF network, these molecules mediate oocyte maturation and competence in preparation for the action of LH. FSH isoforms regulate distinct biological pathways and have specific effects on granulosa cell function and maturation of the ovarian follicle. Their dynamic interactions occur during the follicular cycle; short-living forms are predominant in the pre-ovulatory phase, whereas long-acting molecules characterize the luteal-follicular transition. Recombinant FSH (rFSH) molecules have a reduced number of isoforms and are less acidic, with a shorter half-life. We have investigated sequential stimulation, comparing hFSH + rFSH, vs. rFSH alone and hFSH alone for the entire stimulation phase. Sequential stimulation leads to an E2 per MII oocyte ratio that is much lower than is seen during treatment with the two drugs individually. Although there is a positive tendency in favor of the sequential treatment, there was no significant difference in pregnancy rates, even taking frozen embryos into consideration. The cumulus cell transcriptome varies considerably between the treatments, although with no clear significance. When comparing pregnant vs. non-pregnant patients, in general a decrease in mRNA expression can be observed in the pregnant patients, especially in expression of folic acid receptor 1 and ovostatin 2. This indicates that material has been transferred from CC to the oocyte. However, a common observation in the literature is that variations in the transcriptome of the cumulus cells are highly dependent upon the patient genotype; the potential for applying this strategy as a basis for selecting embryos is, at the very least, questionable. © 2014 Springer Science+Business Media.


PubMed | Beckman Coulter, Yves Menezo Laboratoire Clement, American Hopsital of Paris and Laboratoire Clement
Type: Clinical Study | Journal: Zygote (Cambridge, England) | Year: 2015

The impact of sperm DNA fragmentation on assisted reproductive technology (ART) successes, in terms of outcome, is now established. High levels of DNA strand breaks severely affect the probability of pregnancy. The importance of sperm nucleus condensation in early embryogenesis and, subsequently, on the quality of the conceptus is now emerging. In this article we have compared in situ analyses with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labelling (TUNEL) (for DNA fragmentation) with aniline blue (AB) (for nucleus decondensation), versus flow cytometry (FC) after acridine orange staining, in a double-blinded analysis. In our hands, TUNEL and acridine orange give perfectly comparable results. For decondensation the results are also comparable, but the double-stranded green fluorescence obtained with acridine orange seems to slightly underestimate the decondensation status obtained with AB.


PubMed | Hopital Bichat, Poissy Saint Germain Hospital, University of Versailles and Laboratoire Clement
Type: | Journal: Basic and clinical andrology | Year: 2015

Genes involved in testicular differentiation, spermatogenesis, proliferation and apoptosis of germ cells have been shown to evolve rapidly and display rapid DNA changes. These genes are therefore good candidates for explaining impairments in spermatogenesis. Initial studies of some of these genes appear to confirm this hypothesis. The RHOXF2 candidate gene belongs to the RHOX family clustered in Xq24 and is specifically expressed in the testis. It contains four exons and codes for a 288 amino acid (aa) transcription factor. It has a high degree of homology (>99.9%) with its paralogue RHOXF2B, which is also preferentially expressed in the testis.To sequence RHOXF2 and RHOXF2B in intracytoplasmic sperm injection (ICSI) patients and identify any single-nucleotide polymorphisms (SNPs) associated with impaired spermatogenesis.A cohort of 327 patients in ICSI programmes at Poissy and Bichat hospitals. All patients gave their written, informed consent to participation. One hundred patients had unaffected spermatogenesis and 227 displayed impaired spermatogenesis.The four exons in each of RHOXF2 and RHOXF2B were sequenced in 47 patients with oligospermia or non-obstructive azoospermia. Given that exons 2 and 3 were found to harbour most of the SNPs, only these two exons were sequenced in the remaining 280 subjects.Due to the extremely high degree of sequence identity between RHOXF2 and RHOXF2B, we were not able to distinguish between the sequences of these two genes. Although 9 SNPs were identified, there were no significant frequency differences between ICSI patients with normal vs. impaired spermatogenesis. Two insertions were identified: a 21-nucleotide insertion was retrieved in both groups and a guanine insertion (inducing a premature stop codon) only found in two patients with impaired spermatogenesis.RHOXF2 is a good candidate for rapid evolution by positive selection. Analysis of the polymorphism frequency in exons 2 and 3 did not allow us to correlate the identified SNPs with male infertility. However, a single nucleotide insertion was identified only in men with impaired spermatogenesis. Further work will be needed to establish whether genetic changes in RHOXF2 can give rise to defects in spermatogenesis.


Ferfouri F.,Poissy Medical Center | Ferfouri F.,University of Versailles | Boitrelle F.,Poissy Medical Center | Boitrelle F.,University of Versailles | And 7 more authors.
Molecular Human Reproduction | Year: 2013

Individuals with two independent chromosome rearrangements are rare and meiotic segregation studies are few. Two brothers (P1 and P2) and a cousin (P3) were karyotyped and found to have the same familial reciprocal translocation between the long arm of chromosome 8 and the short arm of chromosome 9: 46,XY,t(8;9)(q24.3;p24). In addition, one brother also had a different de novo reciprocal translocation between the long arm of chromosome 1 and the short arm of chromosome 16: 46,XY,t(1;16)(q21;p11.2)dn,t(8;9)(q24.3;p24)mat. Using locus-specific probes for segments involved in the translocations and for other chromosomes, sperm-FISH analysis was used to investigate the products of meiotic segregation of the translocations and the possibility of an interchromosomal effect (ICE). Sperm nucleus fragmentation was also evaluated. For the t(8;9) translocation, the proportion of unbalanced products was higher for P1 (66.3%, P < 0.0001) than P2 (51.9%) and P3 (50.4%), and the proportion consistent with each meiosis I segregation mode was also different for P1. In addition, for P1, 61.6% of the products of the t(1;16) were unbalanced, and 85.6% of spermatozoa overall included both translocations. No evidence of an ICE was found and sperm nucleus fragmentation rates were similar. Our study suggests that co-segregation of the t(8;9) and the t(1;16) resulted in modifying the proportions of t(8;9) meiotic segregation products found in spermatozoa. This could be due to selection associated with meiotic checkpoints and germ cell death. © The Author 2012. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.


Menezo Y.,London Fertility Associates | Menezo Y.,Laboratoire CLEMENT | Evenson D.,South Dakota State University | Cohen M.,Procrelys | And 2 more authors.
Advances in Experimental Medicine and Biology | Year: 2014

According to worldwide statistics, between one in four and one in five couples have fertility problems. These problems are equally distributed between males and females. Modern lifestyle has obviously increased these problems: endocrine-disrupting chemicals, such as plastic polymer catalysts, alkylphenols, phthalates and so on, and cosmetic additives seem to be strongly involved in this fertility problem. Many of these compounds increase oxidative stress (OS) and thus impair spermatogenesis. The oocyte has only a finite capacity, decreasing with maternal age, to repair sperm-borne decays. To decrease this DNA repair burden, reducing the sperm DNA damages linked to OS is tempting. Antioxidant vitamins are often given haphazardly; they are not very efficient and potentially detrimental. A detailed analysis of the sperm nucleus is mandatory (DNA fragmentation or lack of nuclear condensation) prior to any treatment. Here we discuss new concepts in OS and the corresponding therapeutic approaches. © 2014 Springer Science+Business Media New York.


PubMed | Center for Assisted Fertilization, Clinique Natecia, Bourn Hall Clinic and Laboratoire Clement
Type: Review | Journal: Reproductive biomedicine online | Year: 2016

The negative effect of oxidative stress on the human reproductive process is no longer a matter for debate. Oxidative stress affects female and male gametes and the developmental capacity of embryos. Its effect can continue through late stages of pregnancy. Metabolic disorders and psychiatric problems can also be caued by DNA methylation and epigenetic errors. Age has a negative effect on oxidative stress and DNA methylation, and recent observations suggest that older men are at risk of transmitting epigenetic disorders to their offspring. Environmental endocrine disruptors can also increase oxidative stress and methylation errors. Oxidative stress and DNA methylation feature a common denominator: the one carbon cycle. This important metabolic pathway stimulates glutathione synthesis and recycles homocysteine, a molecule that interferes with the process of methylation. Glutathione plays a pivotal role during oocyte activation, protecting against reactive oxygen species. Assisted reproductive techniques may exacerbate defects in methylation and epigenesis. Antioxidant supplements are proposed to reduce the risk of potentially harmful effects, but their use has failed to prevent problems and may sometimes be detrimental. New concepts reveal a significant correlation between oxidative stress, methylation processes and epigenesis, and have led to changes in media composition with positive preliminary clinical consequences.


Menezo Y.,Laboratoire CLEMENT | Lichtblau I.,Clinique de la Muette | Elder K.,Bourn Hall Clinic
Journal of Assisted Reproduction and Genetics | Year: 2013

The metabolism of pre-implantation embryos is far from being understood. In human embryos, the two major obstacles are the scarcity of material, for obvious ethical reasons, and complete absence of a relevant in vivo control model. Over-extrapolation from animal species to human systems adds to the complexity of the problem. Removal of some metabolites from media has been proposed, such as glucose and essential amino acids, on the basis of their pseudo "toxicity". In contrast, addition of some compounds such as growth factors has been proposed in order to decrease apoptosis, which is a natural physiologic process. These suggestions reflect the absence of global knowledge, and in consequence mask reality. Some aspects of metabolism have been ignored, such as lipid metabolism. Others are seriously underestimated, such as oxidative stress and its relationship to imprinting/methylation, of paramount importance for genetic regulation and chromosomal stability. It has become increasingly obvious that more studies are essential, especially in view of the major extension of ART activities worldwide. © 2013 Springer Science+Business Media New York.


Menezo Y.,Laboratoire CLEMENT | Guerin P.,VetAgro Sup | Elder K.,Bourn Hall Clinic
Reproductive BioMedicine Online | Year: 2015

The oviduct has long been considered a 'pipeline', a tube allowing transit of spermatozoa and embryos; this perspective has been reinforced by the success of human IVF. Evidence accumulated over several decades, however, indicates that embryos can modulate the metabolism of tubal cells in their environment. Human IVF culture media is based on formulations that pass mouse embryo assays as quality control: the requirements of mouse embryos differ from those of human embryos, and therefore conditions for human IVF are far removed from the natural environment of the oviduct. The preimplantation environment, both in vitro and in vivo, is known to affect the health of offspring through mechanisms that influence imprinting. Recent studies also show that male accessory glands act in synergy with the oviduct in providing an optimal environment, and this represents a further perspective on the oviduct's contribution to harmonious embryo development and subsequent long-term health. The metabolism of the human embryo is far from being understood, and a 'return' to in-vivo conditions for preimplantation development is worthy of consideration. Although results obtained in rodents must be interpreted with caution, lessons learned from animal embryo culture must not be neglected. © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.


PubMed | Laboratoire CLEMENT
Type: Journal Article | Journal: Journal of assisted reproduction and genetics | Year: 2013

The metabolism of pre-implantation embryos is far from being understood. In human embryos, the two major obstacles are the scarcity of material, for obvious ethical reasons, and complete absence of a relevant in vivo control model. Over-extrapolation from animal species to human systems adds to the complexity of the problem. Removal of some metabolites from media has been proposed, such as glucose and essential amino acids, on the basis of their pseudo toxicity. In contrast, addition of some compounds such as growth factors has been proposed in order to decrease apoptosis, which is a natural physiologic process. These suggestions reflect the absence of global knowledge, and in consequence mask reality. Some aspects of metabolism have been ignored, such as lipid metabolism. Others are seriously underestimated, such as oxidative stress and its relationship to imprinting/methylation, of paramount importance for genetic regulation and chromosomal stability. It has become increasingly obvious that more studies are essential, especially in view of the major extension of ART activities worldwide.

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