43 research outputs found
Development neurobiology of the stress response: multilevel regulation of corticotropin-releasing hormone function.
The ability to respond to adverse environmental cues is present in the neonatal and infant rat, although in an immature form: A number of laboratories have demonstrated stress-induced elevations of plasma glucocorticoids during the first two postnatal weeks. The limbic and hypothalamic mechanisms controlling the hormonal stress-response during this period are not fully understood and are, therefore, the focus of this report. Both hypothalamic corticotropin-releasing hormone (CRH) and vasopressin contribute to the release of ACTH from the pituitary in the adult. The relative roles of these two peptides during the neonatal (first week) and infant (second week) developmental period, are controversial. Evidence is presented that argues strongly for a major role for CRH. Up-regulation of hypothalamic CRH synthesis is a major component in the mature stress response. CRH-mRNA levels in the hypothalamic PVN are increased with cold stress by ninth postnatal day, but not during the first postnatal week. Further, down-regulation of CRH gene expression by glucocorticoids (GC) constitutes a critical "shut-down" mechanism for the hormonal stress response. In vivo and in vitro experiments supporting the "immaturity" of GC feedback on CRH synthesis during the first postnatal week are described. CRH-mediated neurotransmission, in both the endocrine and neuronal effector arms of the response to stress may be modulated via alteration of receptor number. The first member of the CRH receptor family, CRF1, probably mediates the neuroendocrine effects of CRH. The developmental profile of CRF1-mRNA reveals several distinctive spatial and temporal patterns. In the hippocampal CA1, CA2, and CA3a peak (300-600% adult values) CRF1-mRNA is found on postnatal day 6. In the amygdala, CRH receptor mRNA levels are maximal on the ninth postnatal day (at 180% of adult values). In cortex, a steady decline from high postnatal day 2 levels results in adult levels by 12. These findings demonstrate distinct, regional, age-specific control of the synthesis of CRF1. Receptor expression profile may provide important information regarding modulation of the age-specific roles of CRH in different regions. For example, a high ratio of hippocampus/amygdala receptors may preferentially activate negative hippocampal input to the hypothalamus during the neonatal period. Additionally, increased CRH receptor mRNA in the infant compared with the adult provides a mechanism for enhanced excitatory effect of the peptide at this age. In conclusion, increasing evidence exists for multiple control points of the early postnatal response and adaptation to stress. CRH synthesis in hypothalamus and amygdala, its sensitivity to GC feedback, and the abundance and distribution of at least two distinct CRH receptors in the limbic central nervous system and the pituitary are developmentally regulated. All serve as control points permitting an effective endocrine, autonomic, and behavioral response to stressful environmental cues
Regulation of Lipogenesis by Glucocorticoids and Insulin in Human Adipose Tissue
Patients with glucocorticoid (GC) excess, Cushing's syndrome, develop a classic phenotype characterized by central obesity and insulin resistance. GCs are known to increase the release of fatty acids from adipose, by stimulating lipolysis, however, the impact of GCs on the processes that regulate lipid accumulation has not been explored. Intracellular levels of active GC are dependent upon the activity of 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) and we have hypothesized that 11β-HSD1 activity can regulate lipid homeostasis in human adipose tissue (Chub-S7 cell line and primary cultures of human subcutaneous (sc) and omental (om) adipocytes. Across adipocyte differentiation, lipogenesis increased whilst β-oxidation decreased. GC treatment decreased lipogenesis but did not alter rates of β-oxidation in Chub-S7 cells, whilst insulin increased lipogenesis in all adipocyte cell models. Low dose Dexamethasone pre-treatment (5 nM) of Chub-S7 cells augmented the ability of insulin to stimulate lipogenesis and there was no evidence of adipose tissue insulin resistance in primary sc cells. Both cortisol and cortisone decreased lipogenesis; selective 11β-HSD1 inhibition completely abolished cortisone-mediated repression of lipogenesis. GCs have potent actions upon lipid homeostasis and these effects are dependent upon interactions with insulin. These in vitro data suggest that manipulation of GC availability through selective 11β-HSD1 inhibition modifies lipid homeostasis in human adipocytes
BVT.2733, a Selective 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitor, Attenuates Obesity and Inflammation in Diet-Induced Obese Mice
BACKGROUND: Inhibition of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is being pursued as a new therapeutic approach for the treatment of obesity and metabolic syndrome. Therefore, there is an urgent need to determine the effect of 11β-HSD1 inhibitor, which suppresses glucocorticoid action, on adipose tissue inflammation. The purpose of the present study was to examine the effect of BVT.2733, a selective 11β-HSD1 inhibitor, on expression of pro-inflammatory mediators and macrophage infiltration in adipose tissue in C57BL/6J mice. METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6J mice were fed with a normal chow diet (NC) or high fat diet (HFD). HFD treated mice were then administrated with BVT.2733 (HFD+BVT) or vehicle (HFD) for four weeks. Mice receiving BVT.2733 treatment exhibited decreased body weight and enhanced glucose tolerance and insulin sensitivity compared to control mice. BVT.2733 also down-regulated the expression of inflammation-related genes including monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α) and the number of infiltrated macrophages within the adipose tissue in vivo. Pharmacological inhibition of 11β-HSD1 and RNA interference against 11β-HSD1 reduced the mRNA levels of MCP-1 and interleukin-6 (IL-6) in cultured J774A.1 macrophages and 3T3-L1 preadipocyte in vitro. CONCLUSIONS/SIGNIFICANCE: These results suggest that BVT.2733 treatment could not only decrease body weight and improve metabolic homeostasis, but also suppress the inflammation of adipose tissue in diet-induced obese mice. 11β-HSD1 may be a very promising therapeutic target for obesity and associated disease
No specific adverse pregnancy outcome in singleton pregnancies after assisted reproductive technology (ART) for unexplained infertility
International audienc
Facteurs pronostiques des chances de naissance vivante enfécondation in vitro pour infertilité inexpliquée : étude de cohorte
International audienceObjectivesFor 15 to 30% of infertile couples, no etiology can be found, leading to the diagnosis of “unexplained infertility”.The aim of our study was to identify prognostic factors for live birth following in vitro fertilization(IVF) for these couples.MethodsA retrospective, monocentric study on a cohort of couples undergoing IVF for unexplained infertility withthe woman aged ≤ 40 years old. Primary analysis compared couples with a live birth following IVF versuschildless couples following IVF.ResultsBetween January 2014 and December 2018, 104 couples were included, 196 ovarian punctures were performed,followed by 234 embryo transfers (fresh or cryopreserved) which resulted in 43 deliveries. The cumulativelive birth rate was 40.4% per couple. Before IVF attempts, no clinical or paraclinical prognosticfactors between the two groups was observed. However, multivariate analysis showed several biological factors of good prognosis in course of treatment, such as a higher number of mature oocytes and better qualityembryos in “live birth” group.ConclusionsFor a couple, the chances of having a child following IVF unexplained infertility are 40.4%. However,no clinical characteristic enabled us to identify favourable or unfavourable prognosis factors before startingART. The prognostic factors identified during the attempt are interesting to advise the pursue of the IVF ornot
Elective single embryo transfer policy at 48/72 h: Which results after fresh transfers and frozen/thawed transfers?
International audienceObjectives. - To evaluate our elective single embryo transfer policy performed at 48/72 h and define predictive factors of pregnancy after frozen/thawed embryo transfer. Methods. - Analysis of 289 elective single embryo transfers (eSET) performed in a selected population in the ART center of Marseille University Hospital from January 2005 to December 2011, as well as the 325 following frozen/thawed embryo transfers performed in this population between May 2005 and December 2012. Results. - Cumulative pregnancy rate/oocyte retrieval was of 62.6%; 45% of the couples obtained the birth of at least one child. During this studied period, cumulative pregnancy and delivery rates in the whole population remained stable while multiple delivery rate/delivery clearly decreased. Elective single embryo after frozen/thawed transfer gave satisfying results (24.6% pregnancy/transfer) only in the lack of lysis or in case of mild lysis (1-25%) of the transferred embryo. Conclusion. - The implementation of an eSET policy gives satisfying results, depending largely on embryo quality. By proposing eSET to a well-targeted population, chosen both on clinical and biological criteria, a clear reduction of cumulative multiple delivery rate/delivery was obtained in our center over this period, without any global decrease of cumulative pregnancy rate/attempt. Embryo quality is a major factor of success, especially in frozen/thawed cycles. The elective single embryo frozen/thawed transfer should be carried out only if embryo lysis after thawing does not exceed 25%. (C) 2015 Elsevier Masson SAS. All rights reserved
Soluble CD146, an innovative and non-invasive biomarker of embryo selection for in-vitro fertilization
International audienceAlthough progress was made in in vitro fertilization (IVF) techniques, the majority of embryos transferred fail to implant. Morphology embryo scoring is the standard procedure for most of IVF centres for choosing the best embryo, but remains limited since even the embryos classified as ÂŞtop qualityÂş may not implant. As it has been shown that i) CD146 is involved in embryo implantation and ii) membrane form is shed to generate soluble CD146 (sCD146), we propose that sCD146 in embryo supernatants may constitute a new biomarker of embryo selection. Immunocytochemical staining showed expression of CD146 in early embryo stages and sCD146 was detected by ELISA and Western-blot in embryo supernatants from D2. We retrospectively studied 126 couples who underwent IVF attempt. The embryo culture medium from each transferred embryo (n = 222) was collected for measurement of sCD146 by ELISA. Significantly higher sCD146 concentrations were present in embryo supernatants that did not implant (n = 185) as compared to those that successfully implanted (n = 37) (1310 +/- 1152 pg.mL-1 vs. 845+/- 1173 pg.mL-1, p = 0.024). Sensitivity analysis performed on single embryo transfers (n = 71) confirmed this association (p = 0.0054). The computed ROC curve established that the optimal sCD146 concentration for embryo implantation is under 1164 pg.mL-1 (sensitivity: 76%, specificity: 48%, PPV: 25% and NPV: 92%). Over this sCD146 threshold, the implantation rate was significantly lower (9% with sCD146 levels >1164 pg.ml-1 vs. 22% with sCD146 levels 1164 pg.mL-1, p = 0.01). Among the embryos preselected by morphologic scoring, sCD146 determination could allow a better selection of the embryo(s), thus improving the success of elective single embryo transfer. This study establishes the proof of concept for the use of sCD146 as a biomarker for IVF by excluding the embryo with the highest sCD146 level. A multicentre prospective study will now be necessary to further establish its use in clinical practice