Interleukin-1 (IL-1) system gene expression in granulosa cells: kinetics during terminal preovulatory follicle maturation in the mare

BACKGROUND: A growing body of evidences suggests that the ovary is a site of inflammatory reactions, and thus, ovarian cells could represent sources and targets of the interleukin-1 (IL-1) system. The purpose of this study was to examine the IL-1 system gene expressions in equine granulosa cells, and to study the IL-1β content in follicular fluid during the follicle maturation. For this purpose, granulosa cells and follicular fluids were collected from the largest follicle at the early dominance stage (diameter 24 ± 3 mm) or during the preovulatory maturation phase, at T0 h, T6 h, T12 h, T24 h and T34 h after induction of ovulation. Cells were analysed by RT-PCR and follicular fluids were studied by gel electrophoresis and immunoblotting. RESULTS: We demonstrated that interleukin-1β (IL-1β), interleukin-1 receptor 2 (IL-1R2) and interleukin-1 receptor antagonist (IL-1RA) genes are expressed in equine granulosa cells. We observed that the IL-1β and IL-1RA mRNA content changed in granulosa cells during the terminal follicular maturation whereas IL-1R2 mRNA did not vary. In follicular fluid, IL-1β content fluctuated few hours after induction of ovulation. CONCLUSIONS: The expression of IL-1β gene in granulosa cells and the follicular fluid IL-1β content seem to be regulated by gonadotropins suggesting that IL-1β could be an intermediate paracrine factor involved in ovulation

In vivo effect of interleukin-1beta and interleukin-1RA on oocyte cytoplasmic maturation, ovulation, and early embryonic development in the mare

A growing body of evidence suggests that the interleukin-1 system is involved in periovulatory events. Previous work from our lab demonstrated that in the mare, interleukin-1beta (IL-1beta) increases the ovulatory rate of metaphase II oocytes. The present study was conducted to analyze in vivo the effect of IL-1 on oocyte cytoplasmic maturation, ovulation and pregnancy rate. In the present work, IL-1beta (experiment 1, n = 13; experiment 2, n = 25) and interleukin-1RA (IL-1RA; experiment 1, n = 25) were injected intrafollicularly by using the transvaginal ultrasound-guided injection method. Injections were performed on cyclic mares when the diameter of the growing dominant follicle reached 30–34 mm. In experiment 1, mares were inseminated the day of the treatment and all the other day until ovulation. The time of ovulation was determined and a pregnancy diagnosis was performed 14 days after ovulation of the injected follicle. In experiment 2, the cumulus-oocyte complex from each injected follicle was collected by transvaginal ultrasound-guided aspiration 38 h after the intrafollicular injection. Oocyte nuclear stage and oocyte cytoplasmic maturation were assessed by analyzing chromatin configuration, cortical granules migration and mitochondria distribution under a confocal microscope. The results from experiment 1 confirm that an intrafollicular injection of 1 microgram IL-1beta induces ovulation in the mare whereas IL-1RA has no effect at the dose used in the present study. Furthemore, we demonstrated, that in our experimental conditions, IL-1beta and IL-1RA induced a decrease in embryo development. Experiment 2 leads us to observe that IL-1beta is unable to induce cortical granules migration and remodelling of mitochondria, that commonly occurs during oocyte maturation, whereas it acts on nuclear maturation. This result may explain the decrease in embryo development we observed after IL-1beta intrafollicular injection. In conclusion, the present study tends to demonstrate that IL-1beta plays a role in the ovulatory process and may acts on oocyte maturation in the mare, but additional factors are required to complete equine oocyte cytoplasmic maturation to allow embryo development

Production, by co-grinding in a media mill, of porous biodegradable polylactic acid-apatite composite materials for bone tissue engineering

This paper presents the results of a study of the production of porous biodegradable composite materials by co-grinding, followed by scaffolding. Dry powders of polylactic acid and nanocrystalline carbonated apatite, analogous to bone mineral were co-ground in a tumbling ball mill in order to disperse the mineral filler within the polymer. Porous scaffolds were then made by hot moulding the mixture of the two components along with a pore-forming agent which was subsequently eliminated by washing. The mechanical resistance of the scaffolds was evaluated in order to determine the best operating conditions to produce implants offering optimised properties for use as bone substitutes. It was shown that 30 wt.% of filler and 70 wt.% of pore-forming agent produce scaffolds which are sufficiently porous and resistan

Vers une Carte d'Identité Spectrale

National audienceThis paper studies a new spectral analysis strategy for detecting, characterizing and classifying the different “spectral structures” of an unknown stationary process. A “spectral structure” is defined as a sinusoidal wave, a narrow band signal or a noise peak. The spectral analysis strategy is based on the use of several successive and complementary spectral analyses. Then, the proposed methodology provides a way to calculate a “spectral identity card” of each spectral structure, similarly to a real I.D. card. This I.D. card including all information related to this structure results from the fusion of intermediate cards, which are obtained from different spectral analysis algorithms. The I.D. card permits the classification of the detected spectral structure into one of the following four classes: Pure Frequency, Narrow Band, Alarm and Reject

A Spectral Identiy Card

International audienceThis paper studies a new spectral analysis strategy for detecting, characterizing and classifying spectral structures of an unknown stationary process. The spectral structures we consider are defined as sinusoidal waves, narrow band signals or noise peaks. A sum of an unknown number of these structures is embedded in an unknown colored noise. The proposed methodology provides a way to calculate a spectral identity card, which features each of these spectral structures, similarly to a real I.D. The processing is based on a local Bayesian hypothesis testing, which is defined in frequency and which takes account of the noise spectrum estimator. Thanks to a matching with the corresponding spectral window, each I.D. card permits the classification of the associated spectral structure into one of the following four classes: Pure Frequency, Narrow Band, Alarm and Noise. Each I.D. card is actually the result of the fusion of intermediate cards, obtained from complementary spectral analysis methods

Steroid hormones content and proteomic analysis of canine follicular fluid during the preovulatory period

<p>Abstract</p> <p>Background</p> <p>Follicular fluid contains substances involved in follicle activity, cell differentiation and oocyte maturation. Studies of its components may contribute to better understanding of the mechanisms underlying follicular development and oocyte quality. The canine species is characterized by several ovarian activity features that are not extensively described such as preovulatory luteinization, oocyte ovulated at the GV stage (prophase 1) and poly-oocytic follicles. In this study, we examined the hypothesis that the preovulatory LH surge is associated with changes in steroid and protein content of canine follicular fluid prior to ovulation.</p> <p>Methods</p> <p>Follicular fluid samples were collected from canine ovaries during the preovulatory phase, before (pre-LH; n = 16 bitches) and after (post-LH; n = 16) the LH surge. Blood was simultaneously collected. Steroids were assayed by radioimmunoassay and proteomic analyses were carried out by 2D-PAGE and mass spectrometry.</p> <p>Results</p> <p>The concentrations of 17beta-estradiol and progesterone at the pre-LH stage were 737.2 +/- 43.5 ng/ml and 2630.1 +/- 287.2 ng/ml in follicular fluid vs. 53 +/- 4.1 pg/ml and 3.9 +/- 0.3 ng/ml in plasma, respectively. At that stage, significant positive correlations between follicular size and intra-follicular steroid concentrations were recorded. After the LH peak, the intrafollicular concentration of 17beta-estradiol decreased significantly (48.3 +/- 4.4 ng/ml; p < 0.001), whereas that of progesterone increased (11690.2 +/- 693.6 ng/ml; p < 0.001). Plasmatic concentration of 17beta-estradiol was not modified (49 +/- 9.6 pg/ml) after the LH peak, but that of progesterone significantly increased (9.8 +/- 0.63 ng/ml).</p> <p>Proteomic analysis of canine follicular fluid identified 38 protein spots, corresponding to 21 proteins, some of which are known to play roles in the ovarian physiology. The comparison of 2D-PAGE patterns of follicular fluids from the pre- and post-LH stages demonstrated 3 differentially stained single spot or groups of spots. One of them was identified as complement factor B. A comparison of follicular fluid and plasma protein patterns demonstrated a group of 4 spots that were more concentrated in plasma than in follicular fluid, and a single spot specific to follicular fluid. These proteins were identified as gelsolin and clusterin, respectively.</p> <p>Conclusion</p> <p>Our results provide the first demonstration of size-related changes in the steroid concentrations in canine follicular fluid associated with the LH surge. 2D protein mapping allowed identification of several proteins that may play a role in follicle physiology and ovarian activity at the preovulatory stage. This may help in the future to explain and to better understand the species specificities that are described in dogs.</p

Quelle place l’enseignement a-t-il parmi les motivations et projets professionnels des étudiants en Education physique?

peer reviewedIl est commun de considérer que les études en éducation physique conduisent exclusivement à une carrière dans l’enseignement. Toutefois, les recherches portant sur les aspirations professionnelles des étudiants entrant dans ce type de formation sont relativement rares et il n’est pas possible actuellement de déterminer si tous les étudiants possèdent réellement cette vocation «pédagogique». En Communauté française de Belgique, la présence et le succès de 12 établissements de formation en éducation physique a incité le Ministère de l’Enseignement supérieur et de la Recherche scientifique à commander une étude portant sur les motivations des jeunes qui s’engagent dans cette orientation de formation

Production par co-broyage de matériaux composites poreux biodégradables à usage orthopédique

L’article présente les résultats d’une étude sur la production de matériaux composites poreux biodégradables par co-broyage suivi d’une mise en forme. De l’acide polylactique et une apatite nanocristalline carbonatée analogue au minéral osseux, sous forme de poudres, ont été cobroyés dans un broyeur à boulets afin de disperser la charge minérale dans le polymère. Des implants poreux ont ensuite été réalisés en moulant à chaud le mélange des deux constituants et un agent porogène qui a ensuite été éliminé par lessivage. La résistance mécanique des implants a enfin été caractérisée. Il a été montré que des pourcentages de 30 % de charge et 70 % d’agent porogène permettent de produire des implants suffisamment poreux et résistants

Cumulus expansion, nuclear maturation and connexin 43, cyclooxygenase-2 and FSH receptor mRNA expression in equine cumulus-oocyte complexes cultured in vitro in the presence of FSH and precursors for hyaluronic acid synthesis

The aim of this study was to investigate cumulus expansion, nuclear maturation and expression of connexin 43, cyclooxygenase-2 and FSH receptor transcripts in equine cumuli oophori during in vivo and in vitro maturation in the presence of equine FSH (eFSH) and precursors for hyaluronic acid synthesis. Equine cumulus-oocyte complexes (COC) were cultured in a control defined medium supplemented with eFSH (0 to 5 micrograms/ml), Fetal Calf Serum (FCS), precursors for hyaluronic acid synthesis or glutamine according to the experiments. After in vitro maturation, the cumulus expansion rate was increased with 1 microgram/ml eFSH, and was the highest with 20% FCS. It was not influenced by precursors for hyaluronic acid synthesis or glutamine. The expression of transcripts related to cumulus expansion was analyzed in equine cumulus cells before maturation, and after in vivo and in vitro maturation, by using reverse transcription-polymerase chain reaction (RT-PCR) with specific primers. Connexin 43, cyclooxygenase-2 (COX-2) and FSH receptor (FSHr) mRNA were detected in equine cumulus cells before and after maturation. Their level did not vary during in vivo or in vitro maturation and was influenced neither by FSH nor by precursors for hyaluronic acid synthesis. Results indicate that previously reported regulation of connexin 43 and COX-2 proteins during equine COC maturation may involve post-transcriptional mechanisms