scholarly journals Use of the progesterone (P4) receptor antagonist aglepristone to characterize the role of P4 withdrawal for parturition and placental release in cows

Reproduction ◽  
2010 ◽  
Vol 140 (4) ◽  
pp. 623-632 ◽  
Author(s):  
Sima Shenavai ◽  
Bernd Hoffmann ◽  
Marc Dilly ◽  
Christiane Pfarrer ◽  
Gözde R Özalp ◽  
...  
Keyword(s):  
Cesarean Section ◽  
Receptor Antagonist ◽  
Tissue Remodeling ◽  
Giant Cells ◽  
Normal Term ◽  
Estrogen Synthesis ◽  
Placental Membranes ◽  
Limited Spectrum ◽  
Trophoblast Giant Cells

In late pregnant cows, progesterone (P4) is mainly of luteal origin. However, the trophoblast may provide high local P4concentrations in the uterus. To test for the importance of a complete P4withdrawal for parturition-related processes and placental release, the P4receptor (PGR) blocker aglepristone (Ap) was administered to three cows on days 270 and 271 of pregnancy. A complete opening of the cervix was observed 46.5±7.3 h after the start of treatment. However, expulsion of the calves was impaired obviously because of insufficient myometrial activity, and placental membranes were retained for at least 10 days. Measurement of P4concentrations indicated that PGR blockage induced luteolysis. To investigate the role of P4withdrawal for the prepartal tissue remodeling of the placentomes, the caruncular epithelium was evaluated by morphometry, and the percentage of trophoblast giant cells (TGCs) relative to the total number of trophoblast cells were assessed. Caruncular epithelium in Ap-treated cows (D272+Ap) was immature (30.5±3.3%) and not different from untreated controls (elected cesarean section (CS) on day 272; D272-CS; 31.5±1.4%), whereas it was significantly reduced at normal term (D280.5±1.3; 21.0±6.1%;P=0.011). Correspondingly, the percentage of TGCs were 20.1±1.4 in D272+Ap, 22.1±4.8 in D272-CS, and 9.8±3.9 at term (P=0.001). No effect was detected on placental estrogen synthesis. The results showed that in late pregnant cows, P4withdrawal only induces a limited spectrum of the processes related to normal parturition and is not a crucial factor for the prepartal tissue remodeling in placentomes and the timely release of the placenta.

Epigenetic regulation of placental endocrine lineages and complications of pregnancy

2013 ◽  
Vol 41 (3) ◽  
pp. 701-709 ◽  
Author(s):  
Rosalind M. John
Keyword(s):  
Genomic Imprinting ◽  
Giant Cells ◽  
In Utero ◽  
Imprinted Genes ◽  
Endocrine Organ ◽  
Fetal Physiology ◽  
Trophoblast Giant Cells ◽  
In Utero Development ◽  
Genetic Conflicts

A defining feature of mammals is the development in utero of the fetus supported by the constant flow of nutrients from the mother obtained via a specialized organ: the placenta. The placenta is also a major endocrine organ that synthesizes vast quantities of hormones and cytokines to instruct both maternal and fetal physiology. Nearly 20 years ago, David Haig and colleagues proposed that placental hormones were likely targets of the epigenetic process of genomic imprinting in response to the genetic conflicts imposed by in utero development [Haig (1993) Q. Rev. Biol. 68, 495–532]. There are two simple mechanisms through which genomic imprinting could regulate placental hormones. First, imprints could directly switch on or off alleles of specific genes. Secondly, imprinted genes could alter the expression of placental hormones by regulating the development of placental endocrine lineages. In mice, the placental hormones are synthesized in the trophoblast giant cells and spongiotrophoblast cells of the mature placenta. In the present article, I review the functional role of imprinted genes in regulating these endocrine lineages, which lends support to Haig's original hypothesis. I also discuss how imprinting defects in the placenta may adversely affect the health of the fetus and its mother during pregnancy and beyond.

scholarly journals Plac1 Expression Pattern at the Mouse Fetomaternal Interface and Involvement in Trophoblast Differentiation

2017 ◽  
Vol 43 (5) ◽  
pp. 2001-2009 ◽  
Author(s):  
Yanli Gu ◽  
Junhui Wan ◽  
Lv Yao ◽  
Nan-Ni Peng ◽  
Wen-Lin Chang
Keyword(s):  
Expression Pattern ◽  
Giant Cells ◽  
Specific Gene ◽  
Trophoblast Differentiation ◽  
Spatiotemporal Expression ◽  
Trophoblast Stem Cell ◽  
Trophoblast Giant Cells ◽  
Ectoplacental Cone

Background/Aims: It is well known that Plac1 is a placenta-specific gene; however, its spatiotemporal expression pattern and exact role at t h e mouse fetomaternal interface r e m a i n s unclear. Methods: In situ hybridization (ISH) was used to localize the Plac1 mRNA at the mouse fetomaternal interface. A trophoblast stem cell (TS) differentiation model with Plac1 shRNA-overexpressing lentivirus was employed to investigate the possible role of Plac1 in placentation. Real-time RT-PCR was used to detect changes in gene expression. Results: Plac1 was exclusively expressed in the ectoplacental cone (EPC) as well as in 8.5 and 9.5 days post-coitum (dpc) embryos. Subsequently, Plac1 expression was abundant in the spongiotrophoblast layer and moderately in the labyrinth layer until 13.5 dpc, and declined thereafter. Interestingly, Plac1 was also expressed by secondary trophoblast giant cells and glycogen trophoblast cells, but not in primary trophoblast giant cells. Plac1 transcription was increased during the TS differentiation (P < 0.01), and knockdown of Plac1 significantly impaired TS differentiation. Conclusion: Plac1 is abundantly expressed at the fetomaternal interface and in all trophoblast subtypes except in primary trophoblast giant cells. Plac1 knockdown retarded the progress of TS differentiation, indicating that Plac1 is necessary for normal trophoblast differentiation into various trophoblast subpopulations.

scholarly journals A Potential Role and Contribution of Androgens in Placental Development and Pregnancy

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 644
Author(s):  
Agata M. Parsons ◽  
Gerrit J. Bouma
Keyword(s):  
Fetal Development ◽  
Fetal Loss ◽  
Membrane Receptors ◽  
Placental Development ◽  
Placental Function ◽  
Fetal Physiology ◽  
Estrogen Synthesis ◽  
And Function ◽  
Pregnancy Disorders

Successful pregnancy requires the establishment of a highly regulated maternal–fetal environment. This is achieved through the harmonious regulation of steroid hormones, which modulate both maternal and fetal physiology, and are critical for pregnancy maintenance. Defects in steroidogenesis and steroid signaling can lead to pregnancy disorders or even fetal loss. The placenta is a multifunctional, transitory organ which develops at the maternal–fetal interface, and supports fetal development through endocrine signaling, the transport of nutrients and gas exchange. The placenta has the ability to adapt to adverse environments, including hormonal variations, trying to support fetal development. However, if placental function is impaired, or its capacity to adapt is exceeded, fetal development will be compromised. The goal of this review is to explore the relevance of androgens and androgen signaling during pregnancy, specifically in placental development and function. Often considered a mere precursor to placental estrogen synthesis, the placenta in fact secretes androgens throughout pregnancy, and not only contains the androgen steroid nuclear receptor, but also non-genomic membrane receptors for androgens, suggesting a role of androgen signaling in placental function. Moreover, a number of pregnancy disorders, including pre-eclampsia, gestational diabetes, intrauterine growth restriction, and polycystic ovarian syndrome, are associated with abnormal androgen levels and androgen signaling. Understanding the role of androgens in the placenta will provide a greater understanding of the pathophysiology of pregnancy disorders associated with androgen elevation and its consequences.

Metabotropic glutamate receptor dependent EPSP and EPSP-spike potentiation in area CA1 of the submerged rat hippocampal slice

1996 ◽  
Vol 76 (5) ◽  
pp. 3126-3135 ◽  
Author(s):  
N. A. Breakwell ◽  
M. J. Rowan ◽  
R. Anwyl
Keyword(s):  
Nmda Receptor ◽  
Receptor Antagonist ◽  
Cell Body ◽  
Metabotropic Glutamate Receptor ◽  
Long Term Potentiation ◽  
High Frequency Stimulation ◽  
Excitatory Postsynaptic Potential ◽  
Area Ca1 ◽  
Gabaa Receptor Antagonist

1. We reexamined the important areas of conflict in (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid [(1S,3R)-ACPD]-induced potentiation of the field excitatory postsynaptic potential (EPSP) and, for the first time, investigated the role of mGluRs in EPSP-spike (E-S) coupling. 2. (1S,3R)-ACPD (10 microM) bath applied for 20 min consistently induced a long-lasting potentiation of the dendritic EPSP in area CA1 of submerged rat hippocampal slices, which was considerably faster in onset than described previously. 3. This effect was not associated with any change in presynaptic fiber volley but was dependent on both an intact CA3 connection, because removal of area CA3 blocked (1S,3R)-ACPD-induced potentiation, and also on functional N-methyl-D-aspartate (NMDA) receptors, because (1S,3R)-ACPD-induced potentiation was blocked by inclusion of the NMDA receptor antagonist D(-)-2-amino-5-phosphonopentanoic acid (AP5; 50 microM). 4. (1S,3R)-ACPD induced a long-lasting potentiation of the population spike (PS) amplitude that was consistently larger than that of the EPSP measured in the cell body area. This EPSP-PS (E-S) potentiation was blocked by inclusion of the gamma-aminobuturic acid-A (GABAA) receptor antagonist, picrotoxin (50 microM). 5. E-S potentiation induced by high-frequency stimulation (HFS), which was of the same magnitude as that induced by (1S,3R)-ACPD, was blocked by the mGluR-selective antagonist (+)-alpha-methyl-4-carboxyphenylglycine (+MCPG; 250 microM). +MCPG also blocked HFS-induced long-term potentiation (LTP) of the EPSP measured in the cell body. 6. These results suggest that (1S,3R)-ACPD-induced potentiation is NMDA receptor dependent, contrary to some previous findings, and provide further evidence that both synaptic and E-S potentiation induced by (1S,3R)-ACPD share common mechanisms of expression with HFS-induced LTP. The data emphasize the important role of mGluRs in induction of EPSP LTP and E-S potentiation.

scholarly journals Role of interleukin-25 in development of spontaneous arthritis in interleukin-1 receptor antagonist-deficient mice

2017 ◽  
Vol 12 ◽  
pp. 62-65
Author(s):  
Yasuharu Abe ◽  
Aya Nambu ◽  
Sachiko Yamaguchi ◽  
Ayako Takamori ◽  
Hajime Suto ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Interleukin 1 ◽  
Interleukin 1 Receptor Antagonist ◽  
Interleukin 25 ◽  
Deficient Mice

scholarly journals Evidence for the Regulatory Role of Lipocalin 2 in High-Fat Diet-Induced Adipose Tissue Remodeling in Male Mice

Endocrinology ◽  
2013 ◽  
Vol 154 (10) ◽  
pp. 3525-3538 ◽  
Author(s):  
Hong Guo ◽  
Merlijn Bazuine ◽  
Daozhong Jin ◽  
Merry M. Huang ◽  
Samuel W. Cushman ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
High Fat Diet ◽  
Adipocyte Differentiation ◽  
Tissue Remodeling ◽  
Peroxisome Proliferator ◽  
Lipocalin 2 ◽  
Peroxisome Proliferator Activated Receptor ◽  
Adipose Tissue Remodeling ◽  
Fat Depot

Lipocalin 2 (Lcn2) has previously been characterized as an adipokine/cytokine playing a role in glucose and lipid homeostasis. In this study, we investigate the role of Lcn2 in adipose tissue remodeling during high-fat diet (HFD)-induced obesity. We find that Lcn2 protein is highly abundant selectively in inguinal adipose tissue. During 16 weeks of HFD feeding, the inguinal fat depot expanded continuously, whereas the expansion of the epididymal fat depot was reduced in both wild-type (WT) and Lcn2−/− mice. Interestingly, the depot-specific effect of HFD on fat mass was exacerbated and appeared more pronounced and faster in Lcn2−/− mice than in WT mice. In Lcn2−/− mice, adipocyte hypertrophy in both inguinal and epididymal adipose tissue was more profoundly induced by age and HFD when compared with WT mice. The expression of peroxisome proliferator-activated receptor-γ protein was significantly down-regulated, whereas the gene expression of extracellular matrix proteins was up-regulated selectively in epididymal adipocytes of Lcn2−/− mice. Consistent with these observations, collagen deposition was selectively higher in the epididymal, but not in the inguinal adipose depot of Lcn2−/− mice. Administration of the peroxisome proliferator-activated receptor-γ agonist rosiglitazone (Rosi) restored adipogenic gene expression. However, Lcn2 deficiency did not alter the responsiveness of adipose tissue to Rosi effects on the extracellular matrix expression. Rosi treatment led to the further enlargement of adipocytes with improved metabolic activity in Lcn2−/− mice, which may be associated with a more pronounced effect of Rosi treatment in reducing TGF-β in Lcn2−/− adipose tissue. Consistent with these in vivo observations, Lcn2 deficiency reduces the adipocyte differentiation capacity of stromal-vascular cells isolated from HFD-fed mice in these cells. Herein Rosi treatment was again able to stimulate adipocyte differentiation to a similar extent in WT and Lcn2−/− inguinal and epididymal stromal-vascular cells. Thus, combined, our data indicate that Lcn2 has a depot-specific role in HFD-induced adipose tissue remodeling.

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