In Vitro Fertilization and Embryo Culture Strongly Impact the Placental Transcriptome in the Mouse Model

BACKGROUND: Assisted Reproductive Technologies (ART) are increasingly used in humans; however, their impact is now questioned. At blastocyst stage, the trophectoderm is directly in contact with an artificial medium environment, which can impact placental development. This study was designed to carry out an in-depth analysis of the placental transcriptome after ART in mice. METHODOLOGY/PRINCIPAL FINDINGS: Blastocysts were transferred either (1) after in vivo fertilization and development (control group) or (2) after in vitro fertilization and embryo culture. Placentas were then analyzed at E10.5. Six percent of transcripts were altered at the two-fold threshold in placentas of manipulated embryos, 2/3 of transcripts being down-regulated. Strikingly, the X-chromosome harbors 11% of altered genes, 2/3 being induced. Imprinted genes were modified similarly to the X. Promoter composition analysis indicates that FOXA transcription factors may be involved in the transcriptional deregulations. CONCLUSIONS: For the first time, our study shows that in vitro fertilization associated with embryo culture strongly modify the placental expression profile, long after embryo manipulations, meaning that the stress of artificial environment is memorized after implantation. Expression of X and imprinted genes is also greatly modulated probably to adapt to adverse conditions. Our results highlight the importance of studying human placentas from ART

H19 Antisense RNA Can Up-Regulate Igf2 Transcription by Activation of a Novel Promoter in Mouse Myoblasts

It was recently shown that a long non-coding RNA (lncRNA), that we named the 91H RNA (i.e. antisense H19 transcript), is overexpressed in human breast tumours and contributes in trans to the expression of the Insulin-like Growth Factor 2 (IGF2) gene on the paternal chromosome. Our preliminary experiments suggested that an H19 antisense transcript having a similar function may also be conserved in the mouse. In the present work, we further characterise the mouse 91H RNA and, using a genetic complementation approach in H19 KO myoblast cells, we show that ectopic expression of the mouse 91H RNA can up-regulate Igf2 expression in trans despite almost complete unmethylation of the Imprinting-Control Region (ICR). We then demonstrate that this activation occurs at the transcriptional level by activation of a previously unknown Igf2 promoter which displays, in mouse tissues, a preferential mesodermic expression (Pm promoter). Finally, our experiments indicate that a large excess of the H19 transcript can counteract 91H-mediated Igf2 activation. Our work contributes, in conjunction with other recent findings, to open new horizons to our understanding of Igf2 gene regulation and functions of the 91H/H19 RNAs in normal and pathological conditions

Immunological studies of mouse decidual cells. I. Membrane markers of decidual cells in the days after implantation

The mechanisms by which the mammalian embryo is protected from allograft rejection by the mother remain unclear at present although several hypotheses have been brought forward (1-3). Recent advances seem to favor the lack of detectable transplantation antigens on the postimplantation trophoblast (4, 5) and of blocking antibodies (6). On the other hand, the decidua in the pregnant uterus may provide a locally privileged environment to the embryo (7, 8). For example, extracts from artificially induced decidua have been shown recently to possess immunosuppressive properties (9). Little is known of the exact role or origin of the decidua that develops and surrounds the postimplantation embryo in the pregnant uterus (10). Most decidual cells seem to be derived from uterine stroma cells that resemble embryonic fibroblasts (11, 12), but morphological data have suggested that some of the cells present in mouse and rat decidua may be lymphocytes or derived from lymphocytes (13, 14). Moreover, recent data show that immunoglobulincontaining cells are present in the mouse decidua shortly aider implantation (15) as well as in the rat metrial gland at a later stage (16). We report here the results of an attempt to define immunologically the cells of the mouse decidua in the days after implantation. It is shown that, in addition to H-2 antigens, Thy-1 antigen can be detected on a sizable fraction of decidual cells and that an apparently increasing number of cells bearing receptors for the Fc portion of immunoglobulin G can be detected in the decidua as pregnancy proceeds from day 6 to day 8

Gender-specific associations between lipids and cognitive decline in the elderly.

International audienceThe aim of this study was to examine the associations between serum lipid levels and cognitive function in a community-based sample of non-demented subjects aged 65 years and over. Participants were 2737 men and 4118 women from a population-based cohort recruited from three French cities. Visual memory, verbal fluency, psychomotor speed, and executive abilities were evaluated at baseline, and after 2, 4, and 7 years of follow-up. Lipid levels were evaluated at baseline. Multiadjusted Cox models stratified by gender were adjusted for sociodemographic and lifestyle characteristics, mental and physical health, and genetic vulnerability to dyslipidemia (apolipoprotein E and A, and cholesteryl ester transfer protein) and taking into account baseline vascular pathologies. In men, a hypercholesterolemic pattern in late-life (high total cholesterol (T-C), low HDL-C, high LDL-C levels) was associated with a 25 to 50% increased risk of decline over 7 years in psychomotor speed, executive abilities, and verbal fluency. Specific associations with low T-C and low LDL-C levels were also observed which may depend on genetic vulnerability to dyslipidemia (related to apolipoprotein A5 and cholesteryl exchange transfer protein). In contrast, in women, a 30% higher rate of decline was found in psychomotor speed with high HDL-C levels and in executive abilities with low levels of LDL-C and triglycerides, in interaction with hormonal treatment. For men and women, vascular pathologies only slightly outweighed the risk related to lipids. This suggests a complex gender-specific pattern of cognitive decline involving genetic vulnerability in men and hormonal status in women

Assisted Reproductive Technology affects developmental kinetics, <it>H19 </it>Imprinting Control Region methylation and <it>H19 </it>gene expression in individual mouse embryos

<p>Abstract</p> <p>Background</p> <p>In the last few years, an increase in imprinting anomalies has been reported in children born from Assisted Reproductive Technology (ART). Various clinical and experimental studies also suggest alterations of embryo development after ART. Therefore, there is a need for studying early epigenetic anomalies which could result from ART manipulations, especially on single embryos. In this study, we evaluated the impact of superovulation, <it>in vitro </it>fertilization (IVF) and embryo culture conditions on proper genomic imprinting and blastocyst development in single mouse embryos.</p> <p>In this study, different experimental groups were established to obtain embryos from superovulated and non-superovulated females, either from <it>in vivo </it>or <it>in vitro </it>fertilized oocytes, themselves grown <it>in vitro </it>or not. The embryos were cultured either in M16 medium or in G1.2/G2.2 sequential medium. The methylation status of <it>H19 </it>Imprinting Control Region (ICR) and <it>H19 </it>promoter was assessed, as well as the gene expression level of <it>H19</it>, in individual blastocysts. In parallel, we have evaluated embryo cleavage kinetics and recorded morphological data.</p> <p>Results</p> <p>We show that:</p> <p>1. The culture medium influences early embryo development with faster cleavage kinetics for culture in G1.2/G2.2 medium compared to M16 medium.</p> <p>2. Epigenetic alterations of the <it>H19 </it>ICR and <it>H19 </it>PP are influenced by the fertilization method since methylation anomalies were observed only in the <it>in vitro </it>fertilized subgroup, however to different degrees according to the culture medium.</p> <p>3. Superovulation clearly disrupted <it>H19 </it>gene expression in individual blastocysts. Moreover, when embryos were cultured <it>in vitro </it>after either <it>in vivo </it>or <it>in vitro </it>fertilization, the percentage of blastocysts which expressed <it>H19 </it>was higher in G1.2/G2.2 medium compared to M16.</p> <p>Conclusion</p> <p>Compared to previous reports utilizing pools of embryos, our study enables us to emphasize a high individual variability of blastocysts in the <it>H19 </it>ICR and <it>H19 </it>promoter methylation and <it>H19 </it>gene expression, with a striking effect of each manipulation associated to ART practices. Our results suggest that <it>H19 </it>could be used as a sensor of the epigenetic disturbance of the utilized techniques.</p

: Lipids and incident dementia in men and women

International audienceCholesterol is a risk factor for developing vascular pathologies, which is in turn an important risk factor for dementia. Previous studies linking lipids and dementia have yielded inconsistent results, which may be attributable to sex differences in the etiology of both vascular disease and dementia. The aim of this study was to evaluate the associations between lipids and incident dementia in 7053 community-dwelling elderly. Dementia was diagnosed at baseline, and 2, 4, and 7-year follow-up. Multivariate Cox models stratified by sex and history of vascular pathologies at baseline were adjusted for sociodemographic, mental and physical health variables, and genetic vulnerability. In men without vascular pathologies, an increased incidence of all-cause dementia but not Alzheimer's disease (AD) was associated with high triglyceride (TG) (HR = 1.55, 95% CI = 1.04-2.32, p = 0.03) and low HDL-cholesterol levels (HR = 1.49, 95% CI = 0.99-2.23, p = 0.05). In women without vascular pathologies, low TG levels were associated with a decreased risk of AD (HR = 0.65, 95% CI = 0.43-0.97, p = 0.03). A decreased risk was also found with high TG levels which may depend on genetic vulnerability to dyslipidemia related to APOA5. For both sexes, no significant associations were found between total- or LDL-cholesterol and dementia or AD. Low HDL-cholesterol and high TG levels may be risk factors of dementia in elderly men whereas low TG is associated with decreased incident AD in women. This data suggests a complex sex-specific etiology of vascular dementia and AD

Modulation of an imprinted gene network in placenta as a compensatory mechanism for normal development of in vitro manipulated mouse embryos

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L’enseignement des sciences infirmières en France : contenus et stratégies

International audienceLa formation en soins infirmiers dans des contextes académiques renforce la nécessité pour les étudiants de s’approprier et de maîtriser la discipline « sciences infirmières ». Dans certains pays, l’enseignement des sciences infirmières est solidement établi et trouve place au même titre que l’enseignement d’autres disciplines scientifiques avec son épistémologie, ses auteurs, ses méthodes, etc. Dans d’autres pays, il est émergent et les manières de faire ne sont pas stabilisées. Le séminaire consacré à « L’enseignement des sciences infirmières » permet d’identifier les éléments fondamentaux épistémologiques, cliniques et scientifiques, de la discipline afin de soutenir son développement en France. Il a pour but d’identifier les contenus fondamentaux relatifs aux sciences infirmières devant être acquis en formation initiale et maîtrisés par l’ensemble des infirmières. Les réponses aux questions posées, relatives à l’épistémologie et aux paradigmes en soins infirmiers, à l’apprentissage de la clinique, à la culture scientifique et à la recherche, à l’enseignement des sciences infirmières, sont fondées sur l’examen des modèles d’autres pays, des partages d’expériences, des discussions dans une vision prospective. Les préconisations tiennent compte des évolutions nécessaires et conformes aux ambitions de santé publique et de service rendu à la société. Elles sont complétées des stratégies permettant leur appropriation par les infirmières elles-mêmes et par les autres professions et les autres champs