1
|
Wang B, Parobchak N, Rosen T. RelB/NF-κB2 regulates corticotropin-releasing hormone in the human placenta. Mol Endocrinol 2012; 26:1356-69. [PMID: 22734038 DOI: 10.1210/me.2012-1035] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Placental CRH may be part of a clock that governs the length of human gestation. The mechanism underlying differential regulation of CRH in the human placenta is poorly understood. We report here that constitutively activated RelB/nuclear factor-κB2 (NF-κB)-2 (p100/p52) acts as an endogenous stimulatory signal to regulate CRH by binding to an NF-κB enhancer of CRH gene promoter in the human placenta. Nuclear staining of NF-κB2 and RelB in villous syncytiotrophoblasts and cytotrophoblasts was coupled with cytoplasmic CRH in syncytial knots of cytotrophoblasts. Chromatin immunoprecipitation identified that CRH gene associated with both RelB and NF-κB2 (p52). Dexamethasone increased synthesis and nuclear translocation of RelB and NF-κB2 (p52) and their association with the CRH gene. In contrast, progesterone, a down-regulator of placental CRH, repressed NF-κB2 (p100) processing, nuclear translocation of RelB and NF-κB2 (p52), and their association with the CRH gene. Luciferase reporter assay determined that the NF-κB enhancer of CRH was sufficient to regulate transcriptional activity of a heterologous promoter in primary cytotrophoblasts. RNA interference-mediated repression of RelB or NF-κB2 resulted in significant inhibition of CRH at both transcriptional and translational levels and prevented the dexamethasone-mediated up-regulation of CRH transcription and translation. These results suggest that the noncanonical NF-κB pathway regulates CRH production in the human placenta and is responsible for the positive regulation of CRH by glucocorticoids.
Collapse
Affiliation(s)
- Bingbing Wang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Maternal-Fetal Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, New Jersey 08901, USA.
| | | | | |
Collapse
|
2
|
Takahashi K. Distribution of urocortins and corticotropin-releasing factor receptors in the cardiovascular system. Int J Endocrinol 2012; 2012:395284. [PMID: 22675352 PMCID: PMC3362921 DOI: 10.1155/2012/395284] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 03/10/2012] [Accepted: 03/15/2012] [Indexed: 12/27/2022] Open
Abstract
Urocortins are human homologues of urotensin I, a fish corticotropin-releasing-factor- (CRF-) like peptide secreted from the urophysis. There are three urocortins: urocortin 1, urocortin 2, and urocortin 3 in mammals. We have shown that urocortin 1 and urocortin 3 are endogenously synthesized in the myocardial cells of human heart and may act on CRF type 2 receptor (CRFR2) expressed in the heart. Expression levels of urocortin 1 in the heart and plasma urocortin 1 levels are elevated in patients with heart failure. Recent studies have shown that urocortins have various biological actions in the cardiovascular system, such as a vasodilator action, a positive inotropic action, a cardioprotective action against ischemia/reperfusion injury, and suppressive actions against the renin angiotensin system and the sympathetic nervous system. Urocortins and CRFR2 may therefore be a potential therapeutic target for cardiovascular diseases, such as congestive heart failure, hypertension, and myocardial infarction.
Collapse
Affiliation(s)
- Kazuhiro Takahashi
- Departments of Endocrinology and Applied Medical Science, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
| |
Collapse
|
3
|
Urocortin in second trimester amniotic fluid: its role as predictor of preterm labor. Mediators Inflamm 2009; 2009:947981. [PMID: 19893766 PMCID: PMC2773374 DOI: 10.1155/2009/947981] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2009] [Revised: 06/27/2009] [Accepted: 08/20/2009] [Indexed: 11/18/2022] Open
Abstract
Backgound. The existence of a “placental clock” which determines the duration of gestation has been previously proposed. It is related to placental CRH secretion and is
active from an early phase in human pregnancy. Urocortin is a specific ligand for the
corticotropin-releasing factor (CRF) receptor expressed by human trophoblast and
fetal membranes. The purpose of this study was to evaluate whether urocortin
concentrations in the early second trimester amniotic fluid might serve to predict
preterm delivery. Method. The urocortin concentrations in early second trimester amniotic fluid were
measured in 41 pregnancies with term delivery and in 41 pregnancies with preterm
delivery by using an immunoradiometric assay. Conditional logistic regression
analysis was used for statistical analysis. Results. Mean amniotic fluid urocortin concentrations in women with preterm labor were 1.55 ± 0.63 ng/mL while those in women with term labor were 1.6 ± 0.49 ng/mL
(p: NS). No statistical significant results were found when comparing amniotic fluid
urocortin concentrations in women with preterm premature rupture of membranes
leading to preterm labor (n = 19) to women with term delivery without premature
rupture of membranes. Conclusion. These results suggest that urocortin concentrations in the amniotic fluid
of genetic amniocentesis are not predictive of preterm labor and birth.
Collapse
|
4
|
Urocortin2 inhibits tumor growth via effects on vascularization and cell proliferation. Proc Natl Acad Sci U S A 2008; 105:3939-44. [PMID: 18308934 DOI: 10.1073/pnas.0712366105] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The corticotropin-releasing factor (CRF) receptor CRFR2 is expressed widely in peripheral tissues and in the vasculature, although its functional roles in those tissues have only recently begun to be elucidated. Previously we found that genetic deletion of CRFR2 resulted in profound postnatal hypervascularization in mice, characterized by both an increase in total vessel number and a dramatic increase in vessel diameter. These data strongly suggested that ligands for CRFR2 act to limit tissue vascularity, perhaps as a counterbalance to factors that promote neovascularization. Urocortin 2 (Ucn2) is a specific ligand for the CRFR2. We hypothesized that activation of CRFR2 by Ucn2 might thus suppress tumor vascularization and consequently limit tumor growth. Here, we show that viral-mediated expression of Ucn2 strikingly inhibits the growth and vascularization of Lewis Lung Carcinoma Cell (LLCC) tumors in vivo. Further, we found that this effect on tumor growth inhibition was independent of whether exposure to Ucn2 occurred before or after establishment of measurable tumors. In vitro, Ucn2 directly inhibited the proliferation of LLCC, suggesting that the tumor-suppressing effects of CRFR2 activation involve a dual mechanism of both a direct inhibition of tumor cell cycling and the suppression of tumor vascularization. These results establish that Ucn2 inhibits tumor growth, suggesting a potential therapeutic role for CRFR2 ligands in clinical malignancies.
Collapse
|
5
|
Sanz E, Monge L, Fernández N, Climent B, Diéguez G, Garcia-Villalón AL. Mechanisms of relaxation by urocortin in renal arteries from male and female rats. Br J Pharmacol 2003; 140:1003-7. [PMID: 14517183 PMCID: PMC1574106 DOI: 10.1038/sj.bjp.0705516] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Urocortin is a peptide recently identified, which is structurally related to the corticotropin-releasing factor (CRF). To analyze the mechanisms that could be involved in its effect on renal arteries from male and female rats, the response to urocortin was studied in isolated segments, 2 mm long, of renal arteries from male and female rats. In renal artery segments precontracted with endothelin-1 (1 nm), urocortin (1 pm-10 nm) produced concentration-dependent relaxation, which was similar in the arteries from male and female rats. This relaxation was reduced by the antagonists of urocortin receptors astressin (1 microM) and alpha-helical CRF(9-41) (1 microM) in arteries from both male and female rats. In renal arteries from female rats, the relaxation to urocortin was reduced by the inhibitor of adenyl cyclase SQ22536 (300 microM), by 8-bromo-cyclic-ADP-ribose (cADPR; 30 microM), an antagonist of the endogenous activator of sarcoplasmic Ca2+ channel cADPR and by ryanodine (1 microM), which produces depletion of sarcoplasmic Ca2+. In renal arteries from male rats, the relaxation to urocortin was increased by ryanodine, and was not modified by SQ22536 or 8-bromo-cADPR. These results suggest that the mechanisms involved in the relaxation to urocortin in renal arteries differ between female and male rats. In female rats, this relaxation may be mediated by the production of cyclic AMP (cAMP), synthesis of cADPR and release of sarcoplasmic Ca2+, whereas in male rats it is not mediated by cAMP.
Collapse
Affiliation(s)
- Elena Sanz
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid 28029, Spain
| | - Luis Monge
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid 28029, Spain
| | - Nuria Fernández
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid 28029, Spain
| | - Belén Climent
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid 28029, Spain
| | - Godofredo Diéguez
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid 28029, Spain
| | - Angel Luis Garcia-Villalón
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid 28029, Spain
- Author for correspondence:
| |
Collapse
|
6
|
Sanz E, Monge L, Fernández N, Martínez MA, Martínez-León JB, Diéguez G, García-Villalón AL. Relaxation by urocortin of human saphenous veins. Br J Pharmacol 2002; 136:90-4. [PMID: 11976272 PMCID: PMC1762105 DOI: 10.1038/sj.bjp.0704670] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Urocortin, an endogenous peptide structurally related to corticotropin-releasing factor (CRF), has potent cardiovascular effects, suggesting that it may be of significance in cardiovascular regulation. The objective of this study was to analyse the effects of urocortin and its action mechanisms on human blood vessels. To this, 3 mm long segments from human saphenous veins were prepared for isometric tension recording in an organ bath. In the segments at basal resting tone, urocortin did not produce any effect, but in the segments precontracted with endothelin-1 (1 - 10 nM), urocortin (1 pM - 10 nM) produced concentration-dependent relaxation. This relaxation was not modified by the inhibitor of nitric oxide synthase NG-nitro-L-arginine methyl ester (L-NAME, 100 microM), but it was potentiated by the cyclo-oxygenase inhibitor meclofenamate (10 microM) and it was reduced by the inhibitors of high-conductance Ca2+-dependent potassium channels tetraethylammonium (TEA, 10 mM) and charybdotoxin (100 nM). These results indicate that human saphenous veins are very sensitive to urocortin, which produces vascular relaxation by a mechanism independent of nitric oxide and dependent of high-conductance Ca2+-dependent potassium channels, and that it may be opposed by the release of vasoconstrictor prostanoids. Therefore, urocortin may be of significance for regulation of the venous circulation in humans.
Collapse
Affiliation(s)
- Elena Sanz
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, 28029 Madrid, Spain
| | - Luis Monge
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, 28029 Madrid, Spain
| | - Nuria Fernández
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, 28029 Madrid, Spain
| | - María Angeles Martínez
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, 28029 Madrid, Spain
| | | | - Godofredo Diéguez
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, 28029 Madrid, Spain
| | - Angel Luis García-Villalón
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, 28029 Madrid, Spain
- Author for correspondence:
| |
Collapse
|
7
|
Huang Y, Chan FL, Lau CW, Tsang SY, He GW, Chen ZY, Yao X. Urocortin-induced endothelium-dependent relaxation of rat coronary artery: role of nitric oxide and K+ channels. Br J Pharmacol 2002; 135:1467-76. [PMID: 11906960 PMCID: PMC1573252 DOI: 10.1038/sj.bjp.0704587] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The mechanisms underlying the vasodilator response to urocortin are incompletely understood. The present study was designed to examine the role of endothelial nitric oxide and Ba(2+)-sensitive K(+) channels in the endothelium-dependent component of urocortin-induced relaxation in the rat left anterior descending coronary artery. 2. Urocortin induced both endothelium-dependent and -independent relaxation with respective pD(2) of 8.64+/-0.03 and 7.90+/-0.10. Removal of endothelium reduced the relaxing potency of urocortin. In rings pretreated with 10(-4) M N(G)-nitro-L-arginine methyl ester, 10(-5) M methylene blue or 10(-5) M ODQ, the urocortin-induced relaxation was similar to that observed in endothelium-denuded rings. L-Arginine (5x10(-4) M) antagonized the effect of N(G)-nitro-L-arginine methyl ester. 3. The relaxant response to urocortin was reduced in endothelium-intact rings preconstricted by 3.5x10(-2) M K(+) and abolished when extracellular K(+) was raised to 5x10(-2) M. Pretreatment with 10(-4) M BaCl(2) significantly inhibited urocortin-induced relaxation. Combined treatment with 10(-4) M BaCl(2) plus 10(-4) M N(G)-nitro-L-arginine methyl ester did not cause further inhibition. In urocortin (10(-8) M)-relaxed rings, BaCl(2) induced concentration-dependent reversal in vessel tone. Tertiapin-Q (10(-6) M) also attenuated urocortin-induced relaxation. In contrast, BaCl(2) did not alter urocortin-induced relaxation in endothelium-denuded rings. 4. In endothelium-denuded rings, hydroxylamine- and nitroprusside-induced relaxation was inhibited by 10(-4) M BaCl(2), but not by 10(-6) M tertiapin-Q. 5. The endothelium of the coronary artery was moderately stained with the antiserum against urocortin. 6. Taken together, the present results indicate that the urocortin-induced endothelium-dependent relaxation of rat coronary arteries is likely attributable to endothelial nitric oxide and subsequent activation of Ba(2+)- or tertiapin-Q-sensitive K(+) channels. The urocortin-induced endothelium-dependent relaxation appears to be mediated by cyclic GMP-dependent mechanisms.
Collapse
Affiliation(s)
- Yu Huang
- Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
| | | | | | | | | | | | | |
Collapse
|
8
|
Petkova-Kirova PS, Gagov HS, Duridanova DB. Urocortin hyperpolarizes stomach smooth muscle via activation of Ca2+-sensitive K+ currents. J Muscle Res Cell Motil 2001; 21:639-45. [PMID: 11227790 DOI: 10.1023/a:1005653218639] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The effect of urocortin (Uro), a recently discovered neuropeptide with selectivity towards corticotropin-releasing hormone type 2 receptor, was tested on whole cell currents expressed by guinea-pig gastric antrum smooth muscle cells. Uro (1 pmol/l-1 nmol/l) caused a concentration-dependent increase of Ca2+-sensitive K currents (I(K)) up to 500% as compared to control currents and did not affect the kinetics and voltage-dependence of inward Ca2+ currents. The I(K)-increasing effect of Uro was fully antagonized by preliminary emptying of intracellular Ca2+ stores with ryanodine and cyclopiazonic acid, as well as by bath application of selective blockers of adenylyl cyclase and cAMP-dependent protein kinase (PKA), but not by inhibitors of guanylyl cyclase, cGMP-dependent protein kinase, and protein kinase C. Comparable I(K) increase was obtained by forskolin (activator of adenylyl cyclase), Sp-cAMPS (activator of PKA), or by intracellular application of the catalytic subunit of PKA. It was concluded that Uro binds to a selective receptor in antral smooth muscle cells where it stimulates I(K) via PKA-dependent increase of Ca2+ concentration near the plasma membrane due to enhanced release from intracellular calcium stores.
Collapse
|