scholarly journals A link between Notch and progesterone maintains the functionality of the rat corpus luteum

Reproduction ◽  
2015 ◽  
Vol 149 (1) ◽  
pp. 1-10 ◽  
Author(s):  
P Accialini ◽  
S F Hernández ◽  
D Bas ◽  
M C Pazos ◽  
G Irusta ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Corpus Luteum ◽  
Butyl Ester ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Corpora Lutea ◽  
Protein Levels ◽  
Progesterone Production ◽  
Secretase Inhibitor

In this study, we investigated the interaction between the Notch pathway and progesterone to maintain the functionality of the corpus luteum (CL). When Notch signaling is activated, the γ-secretase complex releases the active intracellular domains (NICD) of their receptors, which exert survival effects. We designed studies to analyze whether thein vitroinhibition of Notch affects progesterone production, steroidogenic regulators, apoptotic parameters, and signaling transduction pathways in the cultures of CL isolated from pregnant and superovulated rats. We detected a decrease in progesterone production when corpora lutea (CL) were incubated withN-(N-(3,5-difluorophenacetyl-l-alanyl))-S-phenylglycine t-butyl ester (DAPT), a γ-secretase inhibitor. This effect could be in part due to the decrease detected in the CL protein levels of P450scc because STAR and 3β-hydroxysteroid dehydrogenase were not affected by Notch inhibition. Besides, the addition of aminoglutethimide to the CL culture medium decreased NICD of NOTCH1. We observed an increase in the expression of active CASPASE3 (CASP3) after inhibition by Notch, which was reversed by the presence of progesterone. The BAX:BCLXLratio was increased in CL treated with DAPT and the presence of progesterone reversed this effect. In addition, phosphorylation of AKT was inhibited in CL treated with DAPT, but had no effect on ERK activation. To demonstrate that the action of DAPT is specifically related with the inhibition of Notch, CLs were incubated with DLL4 antibody and a decrease in progesterone production was detected. These results suggest the existence of a novel link between progesterone and the Notch signaling pathway to maintain the functionality of the CL.

scholarly journals Suppression of Notch Signaling Stimulates Progesterone Synthesis by Enhancing the Expression of NR5A2 and NR2F2 in Porcine Granulosa Cells

Genes ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 120
Author(s):  
Rihong Guo ◽  
Fang Chen ◽  
Zhendan Shi
Keyword(s):  
Notch Signaling ◽  
Granulosa Cells ◽  
Butyl Ester ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Progesterone Secretion ◽  
Expression Of Genes ◽  
Porcine Granulosa Cells ◽  
Progesterone Synthesis ◽  
Progesterone Biosynthesis

The conserved Notch pathway is reported to be involved in progesterone synthesis and secretion; however, the exact effects remain controversial. To determine the role and potential mechanisms of the Notch signaling pathway in progesterone biosynthesis in porcine granulosa cells (pGCs), we first used a pharmacological γ-secretase inhibitor, N-(N-(3,5-difluorophenacetyl-l-alanyl))-S-phenylglycine t-butyl ester (DAPT), to block the Notch pathway in cultured pGCs and then evaluated the expression of genes in the progesterone biosynthesis pathway and key transcription factors (TFs) regulating steroidogenesis. We found that DAPT dose- and time-dependently increased progesterone secretion. The expression of steroidogenic proteins NPC1 and StAR and two TFs, NR5A2 and NR2F2, was significantly upregulated, while the expression of HSD3B was significantly downregulated. Furthermore, knockdown of both NR5A2 and NR2F2 with specific siRNAs blocked the upregulatory effects of DAPT on progesterone secretion and reversed the effects of DAPT on the expression of NPC1, StAR, and HSD3B. Moreover, knockdown of NR5A2 and NR2F2 stimulated the expression of Notch3. In conclusion, the inhibition of Notch signaling stimulated progesterone secretion by enhancing the expression of NPC1 and StAR, and the two TFs NR5A2 and NR2F2 acted as downstream TFs of Notch signaling in regulating progesterone synthesis.

Corpus luteum and endometrial function in ewes post partum: a study in vivo and in vitro

1992 ◽  
Vol 4 (1) ◽  
pp. 77 ◽  
Author(s):  
JM Wallace ◽  
CJ Ashworth ◽  
RP Aitken ◽  
MA Cheyne
Keyword(s):  
Corpus Luteum ◽  
Post Partum ◽  
Polyacrylamide Gel Electrophoresis ◽  
Uterine Horn ◽  
Corpora Lutea ◽  
Luteal Function ◽  
Progesterone Production ◽  
Release Device

Induction of ovulation post partum is associated with a high incidence of prematurely regressing corpora lutea. However, inadequate luteal function is not the sole reason for pregnancy failure, because ewes with normal corpus luteum function and successful fertilization also fail to establish pregnancies. The effects of suckling status and the interval from post partum to rebreeding on corpus luteum and endometrial function were examined in vivo and in vitro. Ewes were weaned early or allowed to lactate, induced to ovulate using a progesterone-impregnated controlled internal drug release device and an intramuscular injection of pregnant mare serum gonadotrophin, and inseminated (intrauterine) at either 21 or 35 days post partum (n = 10 per group). A further 10 standard ewes whose interval from parturition was in excess of 150 days were included for comparative purposes. On Day 10 after insemination the pregnancy rate was determined in four ewes from each of the post-partum groups and five standard ewes. These ewes were then ovariectomized and hysterectomized for studies in vitro. The incidence of premature luteal regression, as assessed by progesterone concentrations in peripheral blood was independent of the suckling stimulus but dependent on stage post partum (21 days post partum, 6 of 19 ewes; 35 days post partum, 0 of 19 ewes; P less than 0.05). Luteal function was normal in all standard ewes. Ovulation rate, corpus luteum weight, corpus luteum progesterone content and basal progesterone production in vitro were significantly less in 21-day than in 35-day post-partum ewes. Pregnancy rates as determined on Day 10 or at term were low in all post-partum groups (7 out of the 38 ewes inseminated) compared with standard ewes (8 of 10). Uterine function was assessed by culturing endometrial tissue from the tip and body of each uterine horn in the presence of [3H]leucine for 30 h at 37 degrees C. Incorporation of radiolabel into non-dialysable proteins synthesized and secreted by the endometrium in vitro was independent of uterine horn location and suckling status but was significantly lower (P less than 0.001) in media from 21-day than from 35-day post-partum ewes. Irrespective of treatment group, incorporation of radiolabel was positively correlated with mean plasma progesterone concentrations on Days 2-10 after insemination and with basal progesterone production in vitro. Secreted proteins were detected by two-dimensional-polyacrylamide-gel electrophoresis and fluorography.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Notch pathway activation targets AML-initiating cell homeostasis and differentiation

2013 ◽  
Vol 210 (2) ◽  
pp. 301-319 ◽  
Author(s):  
Camille Lobry ◽  
Panagiotis Ntziachristos ◽  
Delphine Ndiaye-Lobry ◽  
Philmo Oh ◽  
Luisa Cimmino ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Notch Signaling ◽  
Myeloproliferative Neoplasms ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Notch Receptor ◽  
Pathway Activation ◽  
Function Models

Notch signaling pathway activation is known to contribute to the pathogenesis of a spectrum of human malignancies, including T cell leukemia. However, recent studies have implicated the Notch pathway as a tumor suppressor in myeloproliferative neoplasms and several solid tumors. Here we report a novel tumor suppressor role for Notch signaling in acute myeloid leukemia (AML) and demonstrate that Notch pathway activation could represent a therapeutic strategy in this disease. We show that Notch signaling is silenced in human AML samples, as well as in AML-initiating cells in an animal model of the disease. In vivo activation of Notch signaling using genetic Notch gain of function models or in vitro using synthetic Notch ligand induces rapid cell cycle arrest, differentiation, and apoptosis of AML-initiating cells. Moreover, we demonstrate that Notch inactivation cooperates in vivo with loss of the myeloid tumor suppressor Tet2 to induce AML-like disease. These data demonstrate a novel tumor suppressor role for Notch signaling in AML and elucidate the potential therapeutic use of Notch receptor agonists in the treatment of this devastating leukemia.

scholarly journals Loss of PLK2 induces acquired resistance to temozolomide in GBM via activation of Notch signaling

2020 ◽  
Author(s):  
Wahafu Alafate ◽  
Dongze Xu ◽  
Wei Wu ◽  
Jianyang Xiang ◽  
Xudong Ma ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Acquired Resistance ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Gene Expression Omnibus ◽  
Primary Brain Tumor ◽  
Biological Behavior ◽  
Clinical Samples

Abstract BackgroundGlioblastoma (GBM) is a lethal type of primary brain tumor with a median survival less than 15 months. Despite the recent improvements of comprehensive strategies, the outcomes for GBM patients remain dismal. Accumulating evidence indicates that rapid acquired chemoresistance is the major cause of GBM recurrence thus leads to worse clinical outcomes. Therefore, developing novel biomarkers and therapeutic targets for chemoresistant GBM is crucial for long-term cures. MethodsTranscriptomic profiles of glioblastoma were downloaded from gene expression omnibus (GEO) and TCGA database. Differentially expressed genes were analyzed and candidate gene PLK2 was selected for subsequent validation. Clinical samples and corresponding data were collected from our center and measured using immunohistochemistry analysis. Lentiviral transduction and in vivo xenograft transplantation were used to validate the bioinformatic findings. GSEA analyses were conducted to identify potential signaling pathways related to PLK2 expression and further confirmed by in vitro mechanistic assays. ResultsIn this study, we identified PLK2 as an extremely suppressed kinase-encoding gene in GBM samples, particularly in therapy resistant GBM. Additionally, reduced PLK2 expression implied poor prognosis and TMZ resistance in GBM patients. Functionally, up-regulated PLK2 attenuated cell proliferation, migration, invasion, and tumorigenesis of GBM cells. Besides, exogenous overexpression of PLK2 reduced acquired TMZ resistance of GBM cells. Furthermore, bioinformatics analysis indicated that PLK2 was negatively correlated with Notch signaling pathway in GBM. Mechanically, loss of PLK2 activated Notch pathway through negative transcriptional regulation of HES1 and degradation of Notch1.ConclusionLoss of PLK2 enhances aggressive biological behavior of GBM through activation of Notch signaling, indicating that PLK2 could be a prognostic biomarker and potential therapeutic target for chemoresistant GBM.

scholarly journals Structural and functional analysis of the repressor complex in the Notch signaling pathway ofDrosophila melanogaster

2011 ◽  
Vol 22 (17) ◽  
pp. 3242-3252 ◽  
Author(s):  
Dieter Maier ◽  
Patricia Kurth ◽  
Adriana Schulz ◽  
Andrew Russell ◽  
Zhenyu Yuan ◽  
...  
Keyword(s):  
Cell Culture ◽  
Notch Signaling ◽  
Target Genes ◽  
Notch Pathway ◽  
Structural Similarity ◽  
Receptor Activation ◽  
Notch Signaling Pathway ◽  
Repressor Complex

In metazoans, the highly conserved Notch pathway drives cellular specification. On receptor activation, the intracellular domain of Notch assembles a transcriptional activator complex that includes the DNA-binding protein CSL, a composite of human C-promoter binding factor 1, Suppressor of Hairless of Drosophila melanogaster [Su(H)], and lin-12 and Glp-1 phenotype of Caenorhabditis elegans. In the absence of ligand, CSL represses Notch target genes. However, despite the structural similarity of CSL orthologues, repression appears largely diverse between organisms. Here we analyze the Notch repressor complex in Drosophila, consisting of the fly CSL protein, Su(H), and the corepressor Hairless, which recruits general repressor proteins. We show that the C-terminal domain of Su(H) is necessary and sufficient for forming a high-affinity complex with Hairless. Mutations in Su(H) that affect interactions with Notch and Mastermind have no effect on Hairless binding. Nonetheless, we demonstrate that Notch and Hairless compete for CSL in vitro and in cell culture. In addition, we identify a site in Hairless that is crucial for binding Su(H) and subsequently show that this Hairless mutant is strongly impaired, failing to properly assemble the repressor complex in vivo. Finally, we demonstrate Hairless-mediated inhibition of Notch signaling in a cell culture assay, which hints at a potentially similar repression mechanism in mammals that might be exploited for therapeutic purposes.

Prolactin stimulates steroidogenesis by human luteal tissue in vitro

1984 ◽  
Vol 103 (1) ◽  
pp. 107-110 ◽  
Author(s):  
M. G. Hunter
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Progesterone Production ◽  
Luteal Tissue ◽  
Oestradiol Production ◽  
Human Corpus Luteum

ABSTRACT Human luteal tissue recovered from varying stages of the luteal phase was minced and incubated for 3 h and the effect of human chorionic gonadotrophin (hCG), prolactin and hCG + prolactin on progesterone and oestradiol production measured. While hCG generally enhanced both progesterone and oestradiol synthesis, prolactin alone at either 20 or 200 μg/l had no significant effect on steroidogenesis. When prolactin was added along with hCG in four of six corpora lutea, however, progesterone production significantly increased and in three of six corpora lutea oestradiol production was increased above that induced by hCG alone. It is concluded that prolactin may play some role in the control of steroidogenesis by the human corpus luteum. J. Endocr. (1984) 103, 107–110

scholarly journals Loss of PLK2 induces acquired resistance to temozolomide in GBM via activation of notch signaling

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Wahafu Alafate ◽  
Dongze Xu ◽  
Wei Wu ◽  
Jianyang Xiang ◽  
Xudong Ma ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Acquired Resistance ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Gene Expression Omnibus ◽  
Primary Brain Tumor ◽  
Biological Behavior ◽  
Clinical Samples

Abstract Background Glioblastoma (GBM) is a lethal type of primary brain tumor with a median survival less than 15 months. Despite the recent improvements of comprehensive strategies, the outcomes for GBM patients remain dismal. Accumulating evidence indicates that rapid acquired chemoresistance is the major cause of GBM recurrence thus leads to worse clinical outcomes. Therefore, developing novel biomarkers and therapeutic targets for chemoresistant GBM is crucial for long-term cures. Methods Transcriptomic profiles of glioblastoma were downloaded from gene expression omnibus (GEO) and TCGA database. Differentially expressed genes were analyzed and candidate gene PLK2 was selected for subsequent validation. Clinical samples and corresponding data were collected from our center and measured using immunohistochemistry analysis. Lentiviral transduction and in vivo xenograft transplantation were used to validate the bioinformatic findings. GSEA analyses were conducted to identify potential signaling pathways related to PLK2 expression and further confirmed by in vitro mechanistic assays. Results In this study, we identified PLK2 as an extremely suppressed kinase-encoding gene in GBM samples, particularly in therapy resistant GBM. Additionally, reduced PLK2 expression implied poor prognosis and TMZ resistance in GBM patients. Functionally, up-regulated PLK2 attenuated cell proliferation, migration, invasion, and tumorigenesis of GBM cells. Besides, exogenous overexpression of PLK2 reduced acquired TMZ resistance of GBM cells. Furthermore, bioinformatics analysis indicated that PLK2 was negatively correlated with Notch signaling pathway in GBM. Mechanically, loss of PLK2 activated Notch pathway through negative transcriptional regulation of HES1 and degradation of Notch1. Conclusion Loss of PLK2 enhances aggressive biological behavior of GBM through activation of Notch signaling, indicating that PLK2 could be a prognostic biomarker and potential therapeutic target for chemoresistant GBM.

The autonomy of the rabbit corpus luteum

1994 ◽  
Vol 143 (3) ◽  
pp. 423-431 ◽  
Author(s):  
P L Keyes ◽  
J L Kostyo ◽  
R Towns
Keyword(s):  
Cyclic Amp ◽  
Adenylyl Cyclase ◽  
Corpus Luteum ◽  
High Rate ◽  
Cyclase Activity ◽  
Corpora Lutea ◽  
Adenylyl Cyclase Activity ◽  
Luteal Cells ◽  
Progesterone Production

Abstract The rabbit corpus luteum possesses LH receptors that are coupled to adenylyl cyclase, but paradoxically it does not require LH as a luteotrophic factor for the maintenance of progesterone secretion. This suggests that rabbit luteal cells may not respond physiologically to LH. Therefore, the present study was undertaken to investigate the responsiveness of the rabbit corpus luteum of pseudopregnancy to human chorionic gonadotrophin (hCG) which acts on the same receptor as LH. Pseudopregnancy was induced by injection of 40 IU pregnant mare serum gonadotrophin followed 50 h later by an injection of 40 IU hCG (day 0). On days 7 and 11 of pseudopregnancy, corpora lutea were obtained and incubated for 2 or 5 h in the presence of either 0·1 or 1 μg/ml hCG or 1 mm monobutyryl cyclic AMP (bcAMP). Neither hCG nor bcAMP stimulated progesterone production by the isolated corpus luteum, despite a sustained high rate of progesterone production by the tissue throughout the incubation period. By contrast, Graafian follicles removed from the same ovaries and incubated under the same conditions responded both to hCG and bcAMP with large increases in progesterone production. To determine whether the cyclic AMP content of the corpus luteum was altered by in vitro exposure to hCG, day 7 and day 11 corpora lutea were incubated for 5 or 15 min with various concentrations of hCG, and cyclic AMP in the tissue was then measured. Even at the highest concentration of hCG tested (10 μg/ml), the cyclic AMP content of the corpus luteum was unaltered. Given this result, the acute effects of various concentrations of hCG on the adenylyl cyclase activity of homogenates of day 11 corpora lutea were examined. Consistent with previous reports of others, adenylyl cyclase activity was stimulated, but only at a high concentration of hCG (1 μg/ml), and the degree of stimulation of the enzyme (∼75%) was quite modest. By contrast, the adenylyl cyclase activity of homogenates of rabbit Graafian follicles was stimulated by even the lowest concentration of hCG tested (0·01 μg/ml). Thus, the adenylyl cyclase of the rabbit follicle is much more sensitive to hCG stimulation than the luteal form of the enzyme. Given the poor responsiveness of luteal adenylyl cyclase to hCG, the possibility was considered that cyclic AMP production in response to hCG might be obscured by luteal cell phosphodiesterase. When day 11 corpora lutea were incubated with hCG in the presence of the phosphodiesterase inhibitor, isobutyl methylxanthine (5 mm), there was a marked increase in the cyclic AMP content of the tissue. Despite this large increase in endogenous cyclic AMP, progesterone production by the corpora lutea was again unaffected. Thus, the rabbit corpus luteum is insensitive to stimulation in at least two major respects. The adenylyl cyclase coupled to the LH receptor is resistant to stimulation by LH (hCG), and steroidogenesis, as reflected by progesterone production in vitro, is not stimulated acutely by cyclic AMP. These results suggest that progesterone biosynthesis in the rabbit corpus luteum is not a regulated process, but rather a process that becomes autonomous as a result of the differentiation of granulosa cells into luteal cells. Therefore, the role of a luteotrophin, such as oestrogen in the rabbit, is to maintain the health and viability of the luteal cells, which have, as an intrinsic property, the capacity to produce progesterone at a high rate. Journal of Endocrinology (1994) 143, 423–431

Abstract 307: Apoa-1 Binding Protein Regulates Retinal Angiogenesis via Control of Notch Signaling

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Renfang Mao ◽  
Yury Miller ◽  
Longhou Fang
Keyword(s):  
Notch Signaling ◽  
Cholesterol Metabolism ◽  
Binding Protein ◽  
Notch Pathway ◽  
Notch Signaling Pathway ◽  
Vital Role ◽  
Wild Type ◽  
Protein Levels ◽  
Secretase Activity

ApoA-1 binding protein (AIBP), a mediator of cholesterol efflux from endothelia cells to HDL, plays a vital role in zebrafish angiogenesis. Although it is evolutionary conserved from Drosophila to human, its role of angiogenesis in higher vertebrate has not been studied. Thus, we propose that the role of AIBP in angiogenesis is also conserved from zebrafish to mice to humans. Mouse models display tremendous power in the study of human cardiovascular disease as the murine and human vasculatures are highly similar. We therefore generated Aibp -/- mice, which are viable and fertile. We then compared retinal vasculature development in Aibp -/- mice and wild-type control mice by whole mount immunostaining. Our data show that AIBP deficiency in mice results in significantly enhanced angiogenesis, including an increase in the radial extension of vascular plexus, the development of a denser upper capillary layer, and more tip cells as well as filopodia in the retinas. Notch signaling pathway plays an essential role for proper angiogenesis. However, the role of cholesterol metabolism in the Notch pathway is poorly understood. We found the expressions of the Notch downstream targets Hes1, Hey1 and Hey2 were upregulated in Aibp -/- retinas compared to controls. Furthermore, the protein level of Notch intracellular domain (NICD) was decreased in Aibp -/- retinas. These results suggest that the activity of Notch signaling is decreased in retinas from Aibp -/- mice. Mechanistically, we found AIBP positively regulates Notch signaling by affect on γ-secretase activity. Moreover, we performed Matrigel plug assay. Comparing that of wild-type, Matrigel plugs from Aibp -/- mice has more VE-cadherin staining and higher VE-cadherin mRNA expression level; and shows lower Hey1 expression as well as decreased NICD protein levels. It indicates that Matrigel plugs from Aibp -/- mice expresses more blood vessels and show lower Notch signaling activity. Our study demonstrated that AIBP inhibits angiogenesis by activating the Notch pathway and are the first to connect AIBP, a cholesterol metabolism regulator, to Notch signaling.

scholarly journals The Adequate Corpus Luteum: miR-96 Promotes Luteal Cell Survival and Progesterone Production

2017 ◽  
Vol 102 (7) ◽  
pp. 2188-2198 ◽  
Author(s):  
Bushra T. Mohammed ◽  
Sadanand D. Sontakke ◽  
Jason Ioannidis ◽  
W. Colin Duncan ◽  
F. Xavier Donadeu
Keyword(s):  
Cell Survival ◽  
Corpus Luteum ◽  
Cultured Cells ◽  
Ovarian Follicle ◽  
Luteal Cell ◽  
Steroid Production ◽  
Protein Levels ◽  
Candidate Mirnas ◽  
Progesterone Production

Abstract Context: Inadequate progesterone production from the corpus luteum is associated with pregnancy loss. Data available in model species suggest important roles of microRNAs (miRNAs) in luteal development and maintenance. Objective: To comprehensively investigate the involvement of miRNAs during the ovarian follicle-luteal transition. Design: The effects of specific miRNAs on survival and steroid production by human luteinized granulosa cells (hLGCs) were tested using specific miRNA inhibitors. Candidate miRNAs were identified through microarray analyses of follicular and luteal tissues in a bovine model. Setting: An academic institution in the United Kingdom associated with a teaching hospital. hLGCs were obtained by standard transvaginal follicular-fluid aspiration from 35 women undergoing assisted conception. Intervention(s): Inhibition of candidate miRNAs in vitro. Main outcome measure(s): Levels of miRNAs, mRNAs, FOXO1 protein, apoptosis, and steroids were measured in tissues and/or cultured cells. Results: Two specific miRNA clusters, miR-183-96-182 and miR-212-132, were dramatically increased in luteal relative to follicular tissues. miR-96 and miR-132 were the most upregulated miRNAs within each cluster. Database analyses identified FOXO1 as a putative target of both these miRNAs. In cultured hLGCs, inhibition of miR-96 increased apoptosis and FOXO1 protein levels, and decreased progesterone production. These effects were prevented by small interfering RNA-mediated downregulation of FOXO1. In bovine luteal cells, miR-96 inhibition also led to increases in apoptosis and FOXO1 protein levels. Conclusions: miR-96 targets FOXO1 to regulate luteal development through effects on cell survival and steroid production. The miR-183-96-182 cluster could provide a novel target for the manipulation of luteal function.

Sign in / Sign up

Export Citation Format

Share Document