FOXL2 is a Progesterone Target Gene in the Endometrium of Ruminants

Forkhead Box L2 (FOXL2) is a member of the FOXL class of transcription factors, which are essential for ovarian differentiation and function. In the endometrium, FOXL2 is also thought to be important in cattle; however, it is not clear how its expression is regulated. The maternal recognition of pregnancy signal in cattle, interferon-Tau, does not regulate FOXL2 expression. Therefore, in the present study, we examined whether the ovarian steroid hormones that orchestrate implantation regulate FOXL2 gene expression in ruminants. In sheep, we confirmed that FOXL2 mRNA and protein was expressed in the endometrium across the oestrous cycle (day 4 to day 15 post-oestrus). Similar to the bovine endometrium, ovine FOXL2 endometrial expression was low during the luteal phase of the oestrous cycle (4 to 12 days post-oestrus) and at implantation (15 days post-oestrus) while mRNA and protein expression significantly increased during the luteolytic phase (day 15 post-oestrus in cycle). In pregnant ewes, inhibition of progesterone production by trilostane during the day 5 to 16 period prevented the rise in progesterone concentrations and led to a significant increase of FOXL2 expression in caruncles compared with the control group (1.4-fold, p < 0.05). Ovariectomized ewes or cows that were supplemented with exogenous progesterone for 12 days or 6 days, respectively, had lower endometrial FOXL2 expression compared with control ovariectomized females (sheep, mRNA, 1.8-fold; protein, 2.4-fold; cattle; mRNA, 2.2-fold; p < 0.05). Exogenous oestradiol treatments for 12 days in sheep or 2 days in cattle did not affect FOXL2 endometrial expression compared with control ovariectomized females, except at the protein level in both endometrial areas in the sheep. Moreover, treating bovine endometrial explants with exogenous progesterone for 48h reduced FOXL2 expression. Using in vitro assays with COS7 cells we also demonstrated that progesterone regulates the FOXL2 promoter activity through the progesterone receptor. Collectively, our findings imply that endometrial FOXL2 is, as a direct target of progesterone, involved in early pregnancy and implantation

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

FOXL2 is a new progesterone-regulated gene in the endometrium

In mammals, mutual actions of estrogens and progesterone on their uterine receptors are essential for endometrium receptivity and conceptus implantation. In cattle we showed that FOXL2 -a key gene for ovarian differentiation and maintenance- is expressed and regulated in endometrium during oestrous cycle, a finding confirmed in murine and human endometrium. The present study aims to determine if FOXL2 is a progesterone-target gene in the bovine endometrium. Using various experimenta models in cattle, our results indicated (i) a negative correlation between FOXL2 gene expression and progesterone (P4) blood levels (ii) a significant reduction of FOXL2 transcript level in ovariectomized cows supplemented with P4 for 6 days (2.2-fold vs. control ovariectomized cows, P < 0.05) (iii) a significant decrease in FOXL2 mRNA level in bovine endometrial explants incubated with P4 (10-5 M) for 48h (2.4-fold vs. control explants, P < 0.05). No impact of oestradiol on FOXL2 gene expression was detected in these conditions. In order to confirm the regulation of FOXL2 promoter by P4, COS7 cells were transfected with a caprine FOXL2 reporter gene and progesterone receptor (PR) A or B expression vectors. In the presence of PRA and PRB, P4 (10-7 M) stimulated the activity of FOXL2 promoter (2.8-fold). Mutation of the P4 Response Element (PRE) in the caprine FOXL2 promoter abrogated the activity of this promoter in P4-treated COS7 cells overexpressing PRA/PRB. Collectively, our data show that reduced FOXL2 expression in the endometrium during the luteal phase results from the down-regulation of PRA/B known to occur in the presence of P4. Determining the biological actions of FOXL2 will be mandatory to define the contribution of this transcription factor in the regulation of sensor and driver properties of the endometrium

Implantation-related genes in the ovine endometrium are regulated by extracellular vesicles from earlypregnant uterine fluids

National audienc

Les vésicules extra-cellulaires (EVs) de fluide utérin stimulent l’expression de marqueurs de l’implantation dans l’endomètre ovin in vivo

National audienc

Analyses des conséquences du vieillissement sur la physiologie de l’endomètre à l’aide d’un modèle bovin de génome nucléaire fixé

National audienc

Maternal metabolism affects endometrial expression of oxidative stress and FOXL2 genes in cattle.

Intensive selection for milk production has led to reduced reproductive efficiency in high-producing dairy cattle. The impact of intensive milk production on oocyte quality as well as early embryo development has been established but few analyses have addressed this question at the initiation of implantation, a critical milestone ensuring a successful pregnancy and normal post-natal development. Our study aimed to determine if contrasted maternal metabolism affects the previously described sensory properties of the endometrium to the conceptus in cattle. Following embryo transfer at Day 7 post-oestrus, endometrial caruncular (CAR) and intercaruncular (ICAR) areas were collected at Day 19 from primiparous postpartum Holstein-Friesian cows that were dried-off immediately after parturition (i.e., never milked; DRY) or milked twice daily (LACT). Gene quantification indicated no significant impact of lactation on endometrial expression of transcripts previously reported as conceptus-regulated (PLET1, PTGS2, SOCS6) and interferon-tau stimulated (RSAD2, SOCS1, SOCS3, STAT1) factors or known as female hormone-regulated genes (FOXL2, SCARA5, PTGS2). Compared with LACT cows, DRY cows exhibited mRNA levels with increased expression for FOXL2 transcription factor and decreased expression for oxidative stress-related genes (CAT, SOD1, SOD2). In vivo and in vitro experiments highlighted that neither interferon-tau nor FOXL2 were involved in transcriptional regulation of CAT, SOD1 and SOD2. In addition, our data showed that variations in maternal metabolism had a higher impact on gene expression in ICAR areas. Collectively, our findings prompt the need to fully understand the extent to which modifications in endometrial physiology drive the trajectory of conceptus development from implantation onwards when maternal metabolism is altered

Aged endometrium displays perturbations of inflammation-related molecular pathways compared with fertile endometrium in the bovine species

International audienc

Maternal metabolism affects endometrial expression of oxidative stress and <i>FOXL2</i> genes in cattle

<div><p>Intensive selection for milk production has led to reduced reproductive efficiency in high-producing dairy cattle. The impact of intensive milk production on oocyte quality as well as early embryo development has been established but few analyses have addressed this question at the initiation of implantation, a critical milestone ensuring a successful pregnancy and normal post-natal development. Our study aimed to determine if contrasted maternal metabolism affects the previously described sensory properties of the endometrium to the conceptus in cattle. Following embryo transfer at Day 7 post-oestrus, endometrial caruncular (CAR) and intercaruncular (ICAR) areas were collected at Day 19 from primiparous postpartum Holstein-Friesian cows that were dried-off immediately after parturition (i.e., never milked; DRY) or milked twice daily (LACT). Gene quantification indicated no significant impact of lactation on endometrial expression of transcripts previously reported as conceptus-regulated (<i>PLET1</i>, <i>PTGS2</i>, <i>SOCS6</i>) and interferon-tau stimulated (<i>RSAD2</i>, <i>SOCS1</i>, <i>SOCS3</i>, <i>STAT1</i>) factors or known as female hormone-regulated genes (<i>FOXL2</i>, <i>SCARA5</i>, <i>PTGS2</i>). Compared with LACT cows, DRY cows exhibited mRNA levels with increased expression for <i>FOXL2</i> transcription factor and decreased expression for oxidative stress-related genes (<i>CAT</i>, <i>SOD1</i>, <i>SOD2</i>). <i>In vivo</i> and <i>in vitro</i> experiments highlighted that neither interferon-tau nor FOXL2 were involved in transcriptional regulation of <i>CAT</i>, <i>SOD1</i> and <i>SOD2</i>. In addition, our data showed that variations in maternal metabolism had a higher impact on gene expression in ICAR areas. Collectively, our findings prompt the need to fully understand the extent to which modifications in endometrial physiology drive the trajectory of conceptus development from implantation onwards when maternal metabolism is altered.</p></div