scholarly journals CRH Activation of Different Signaling Pathways Results in Differential Calcium Signaling in Human Pregnant Myometrium before and during Labor

2012 ◽  
Vol 97 (10) ◽  
pp. E1851-E1861 ◽  
Author(s):  
Xingji You ◽  
Lu Gao ◽  
Jie Liu ◽  
Chen Xu ◽  
Chunmin Liu ◽  
...  
Keyword(s):  
Calcium Signaling ◽  
Signaling Pathways ◽  
Phospholipase C ◽  
Imaging System ◽  
Uterine Contractility ◽  
Acetoxymethyl Ester ◽  
Before And After ◽  
Gi Protein ◽  
Crh Receptor Type 1

Abstract Context: Our previous study has demonstrated that CRH has differential effects on human uterine contractility before and after onset of labor. Intracellular Ca2+ concentration ([Ca2+]i) mobilization plays an important role in the control of uterine contraction. Objective: Our objective was to investigate the effects of CRH on [Ca2+]i homeostasis in laboring and nonlaboring myometrial cells and determine subsequent signaling involved in [Ca2+]i regulation by CRH. Design: The myometrial tissues were obtained from pregnant women who were undergoing or not undergoing labor at term. [Ca2+]i was determined by Ca2+ imaging system using the fluorescent dye fura-2-acetoxymethyl ester. Western blot analysis, ELISA, and RIA were used to determine the signaling pathways induced by CRH. Results: CRH induced Ca2+ transient in laboring cells, which was blocked by CRH receptor type 1 (CRHR1) antagonist antalarmin. CRHR1 knockdown impaired this effect of CRH. CRH activated Gi protein, decreased cAMP production, and induced phosphorylated phospholipase C-β3 and inositol-1,4,5-triphosphate production. Phospholipase C and inositol-1,4,5-triphosphate receptor inhibitors blocked the CRH-induced Ca2+ transient in laboring cells. CRH did not induce whereas antalarmin induced the Ca2+ transient in nonlaboring cells. Knockdown of CRHR1 impaired the effect of antalarmin. CRH acted on CRHR1 to activate Gs in nonlaboring cells. Forskolin blocked antalarmin-induced Ca2+ transient. Conclusions: CRH acts on CRHR1 to activate different signaling pathways before and after onset of labor, thereby resulting in differential calcium signaling in response to CRH. The signaling pathways of CRHR1 might serve as a target for the development of new therapeutic strategies for preterm birth.

Urocortins exhibit differential effects on PGE2 and PGF2α output via CRHR2 in human myometrium

Reproduction ◽  
2021 ◽  
Author(s):  
Xingji You ◽  
Zixi Chen ◽  
Qianqian Sun ◽  
Ruojing Yao ◽  
Hang Gu ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Mapk Signaling ◽  
Human Myometrium ◽  
Dependent Manner ◽  
Camp Production ◽  
Inflammatory Stimuli ◽  
Crh Receptor Type 1 ◽  
Dose Dependent ◽  
Mapk Signaling Pathways

Urocortins (UCNs), belonging to corticotropin-releasing hormone (CRH) family, exert their function via CRH receptor type 1(CRHR1) and 2 (CRHR2). Our previous studies have demonstrated that CRH acts on CRHR1 to potentiate prostaglandin (PG) output induced by inflammatory stimuli in myometrial cells. In the present study, we sought to investigate the effects of UCNs on prostaglandin (PG) output via CRHR2 in cultured human uterine smooth muscle cells (HUSMCs) from human term myometrium. We found that UCN and UCN3 treatment promoted PGE2 and PGF2α secretion in a dose-dependent manner. In contrast, UCN2 dose-dependently inhibited PGE2 and PGF2α secretion. Their effects could be reversed by CRHR2 antagonist and CRHR2 siRNA. Mechanically, we showed that UCN and UCN3 suppressed cAMP production and led to Gi activation, while UCN2 promoted cAMP production and activated Gs signaling. Further, UCN and UCN3 could activate NF-κB and MAPK signaling pathways. These effects were dependent on Gi signaling. In contrast, UCN did not activate MAPK and NF-κB signaling. UCN and UCN3 stimulation of PG secretion was dependent on Gi/adenylyl cyclase (AC)/cAMP, NF-κB and MAPK signaling pathways, while UCN2 suppression of PG output was through Gs/AC/cAMP signaling pathways. Our data suggest that UCN, UCN2 and UCN3 can finely regulate the secretion of PGs via CRHR2, which facilities the functional status of uterus during pregnancy.

scholarly journals CRH Acts on CRH-R1 and -R2 to Differentially Modulate the Expression of Large-Conductance Calcium-Activated Potassium Channels in Human Pregnant Myometrium

Endocrinology ◽  
2011 ◽  
Vol 152 (11) ◽  
pp. 4406-4417 ◽  
Author(s):  
Chen Xu ◽  
Lu Gao ◽  
Xingji You ◽  
Ling Dai ◽  
Yuan Li ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Receptor Type ◽  
Uterine Contractility ◽  
Myometrial Cells ◽  
Calcium Activated Potassium Channels ◽  
Spontaneous Contractions ◽  
Crh Receptor Type 1 ◽  
Interfering Rna

CRH has been implicated to play a key role in the control of human pregnancy and parturition. Large-conductance potassium channels (BKCa) play a pivotal role in the modulation of uterine contractility during pregnancy. The objectives of the present study were to investigate the effect of CRH on BKCa expression in human pregnant myometrial cells. Myometrial tissues were collected at cesarean section from pregnant women not-in-labor (TNL) or in-labor (TL) at term, and myocytes were isolated and cultured. CRH was identified in human pregnant myometrium and mainly expressed in myometrial myocytes. Cultured myometrial cells were able to secrete CRH. In TNL myometrial cells, CRH treatment increased the expression of BKCa α- and β-subunits. CRH receptor type 1 (CRH-R1) antagonist, antalarmin, decreased whereas CRH receptor type 2 (CRH-R2) antagonist, astressin2b, increased the expression of BKCa. CRH-R2 small interfering RNA (siRNA) caused an increase, but CRH-R1 siRNA resulted in a decrease, in BKCa expression. In contrast to TNL cells, CRH exhibited an opposite effect on BKCa expression in TL myometrial cells, i.e. decreased BKCa expression. Antalarmin enhanced but astressin2b reduced BKCa expression. CRH-R2 siRNA decreased whereas CRH-R1 siRNA increased BKCa expression. 1,3-Dihydro-1-[2-hydroxy-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-2H-benzimidazol-2-one significantly inhibited the frequency of spontaneous contractions of myometrial strips, and this effect was significantly decreased in TL strips compared with TNL ones. Our data suggest that CRH-R1 and CRH-R2 show differential regulation of BKCa expression. These effects mediated by CRH-R1 and CRH-R2 are changed after the onset of labor. This leads us to suggest that CRH may fine-tune myometrial contractility by modulating the expression of BKCa during pregnancy and labor.

scholarly journals Regulation of Estradiol and Progesterone Production by CRH-R1 and -R2 Is through Divergent Signaling Pathways in Cultured Human Placental Trophoblasts

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4918-4928 ◽  
Author(s):  
Lu Gao ◽  
Yi Tao ◽  
Tianxiao Hu ◽  
Weina Liu ◽  
Chen Xu ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Phospholipase C ◽  
Culture Media ◽  
Receptor Type ◽  
Kinase C ◽  
Protein Kinase C Inhibitor ◽  
Crh Receptor Type 1 ◽  
Gαi Protein

Abstract CRH and its related peptides urocortins (UCN) have been identified in placenta and implicated to play pivotal roles in the regulation of pregnancy and parturition in humans. The objectives of present study were to investigate the effects of endogenous CRH and its related peptides in the regulation of steroid production in placenta. Placental trophoblasts were isolated from term placenta tissues and cultured for 72 h. Estradiol (E2) and progesterone (P4) contents in culture media were determined by radioimmunoassay. Treatment of cultured trophoblasts with CRH or UCNI antibody showed decreased E2, whereas increased P4 production. Treatment of cells with CRH receptor type 1 antagonist antalarmin or CRH receptor type 2 (CRH-R2) antagonist astressin-2b also decreased E2 but increased P4 production. Knockdown of CRH receptor type 1 or CRH-R2 cells showed a decrease in E2 production and an increase in P4 production. In CRH-R2 knockdown cells, CRH stimulated GTP-bound Gαs protein and phosphorylated phospholipase C-β3. Adenylyl cyclase and protein kinase A inhibitors blocked CRH-induced increased E2 production but not decreased P4 production. PLC inhibitor U73122 and protein kinase C inhibitor chelerythrine blocked the effects of CRH on E2 and P4 production in CRH-R2 knockdown cells. UCNIII, the specific CRH-R2 agonist, stimulated GTP-bound Gαi protein and phosphorylated phospholipase C-β3 expression. Both U73122 and chelerythrine blocked UCNIII-induced increased E2 production and decreased P4 production. We suggest that CRH and its related peptides might be involved in changes in the progesterone to estrogen ratio during human pregnancy.

scholarly journals Corticotropin-Releasing Hormone (CRH) Depresses N-Methyl-d-Aspartate Receptor-Mediated Current in Cultured Rat Hippocampal Neurons via CRH Receptor Type 1

Endocrinology ◽  
2007 ◽  
Vol 149 (3) ◽  
pp. 1389-1398 ◽  
Author(s):  
Hui Sheng ◽  
Yanmin Zhang ◽  
Jihu Sun ◽  
Lu Gao ◽  
Bei Ma ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Protein Kinase ◽  
Signaling Pathways ◽  
Hippocampal Neurons ◽  
Receptor Type ◽  
Dependent Manner ◽  
Camp Content ◽  
Nmda Current ◽  
Crh Receptor Type 1

CRH, the primary regulator of the neuroendocrine responses to stress, has been shown to modulate synaptic efficacy and the process of learning and memory in hippocampus. However, effects of CRH on N-methyl-d-aspartate (NMDA) receptor, the key receptor for synaptic plasticity, remain unclear. In primary cultured hippocampal neurons, using the technique of whole-cell patch-clamp recordings, we found that CRH (1 pmol/liter to 10 nmol/liter) inhibited NMDA-induced currents in a dose-dependent manner. This effect was reversed by the CRH receptor type 1 (CRHR1) antagonist antalarmin but not by the CRHR2 antagonist astressin-2B, suggesting that CRHR1 mediated the inhibitory effect of CRH. Investigations on the signaling pathways of CRH showed that CRH dose-dependently induced phosphorylated phospholipase C (PLC)-β3 expression and increased intracellular cAMP content in these cells. Blocking PLC activity with U73122 prevented CRH-induced depression of NMDA current, whereas blocking protein kinase A (H89) and adenylate cyclase (SQ22536) failed to affect the CRH-induced depression of NMDA current. Application of inositol-1,4,5-triphosphate receptor (IP3R) antagonist, Ca2+ chelators or protein kinase C (PKC) inhibitors also mainly blocked CRH-induced depression of NMDA currents, suggesting involvement of PLC/IP3R/Ca2+and PLC/PKC signaling pathways in CRH down-regulation of NMDA receptors. Our results suggest that CRH may exert neuromodulatory actions on hippocampus through regulating NMDA receptor function.

DETERMINATION OF BLOOD CORTICOIDS USING THE IN VITRO RESIN UPTAKE OF 3H-PREDNISOLONE

1968 ◽  
Vol 57 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Hironori Nakajima ◽  
Mitsunori Murala ◽  
Masumitsu Nakata ◽  
Takeshi Naruse ◽  
Seiji Kubo
Keyword(s):  
Thyroid Function Test ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Function Test ◽  
Before And After ◽  
Adrenal Response ◽  
Suppression Test

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.

scholarly journals Regulation des Angstverhaltens — zur Rolle neuronaler Netzwerke

BIOspektrum ◽  
2019 ◽  
Vol 25 (7) ◽  
pp. 711-714
Author(s):  
Nina Dedic ◽  
Jan M. Deussing
Keyword(s):  
Stress Response ◽  
Ventral Tegmental Area ◽  
Long Range ◽  
Dopamine Release ◽  
Receptor Type ◽  
Projection Neurons ◽  
Neuronal Circuit ◽  
Brain Reward ◽  
Crh Receptor Type 1

AbstractThe corticotropin-releasing hormone (CRH) system orchestrates the organism’s stress response including the regulation of adaptive be haviours. Here we describe a novel neuronal circuit, which acts anxiety suppressing and positively modulates dopamine release. This anxiolytic circuit comprises inhibitory CRH-expressing, long-range projection neurons within the extended amygdala. These neurons innervate the ventral tegmental area, a prominent brain reward center that expresses high levels of CRH receptor type 1.

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