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Perinatal Research Center, Department of Obstetrics and Gynecology, HMRC 220, University of Alberta, Edmonton, Alberta, Canada T6G 2S2
Address all correspondence and requests for reprints to: Dr. B. F. Mitchell, Perinatal Research Center, Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada T6G 252.
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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B. Our
findings suggest a role for IL-1ß and IL-6 in the transcriptional
regulation of the human OT receptor gene. |
Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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q subfamily to the phospholipase
Cß/Ca2+ signaling pathway
(3, 4).
The expression of uterine oxytocin receptors is highly regulated.
Binding sites for OT in human myometrium increase over 180-fold during
gestation, and this is accompanied by a significant increase in
specific messenger RNA (mRNA) for OTR (5, 6). The human
OTR gene exists as a single copy in the haploid genome and spans
approximately 17 kb, consisting of four exons and three introns
(7, 8). In its 5'-flanking region a variety of putative
nucleotide consensus sequences exist, including binding sites for
activator protein-1 (AP-1), Sp-1, nuclear factor-B (NF-B), acute
phase response element (APRF), NF-interleukin-6 (NF-IL6), and several
half-palindromic estrogen response elements (EREs; Fig. 1
). The proximal promoter region contains
a TATAA-like motif, an Inr element, a growth-associated binding
protein site, and a cAMP response element/AP-1 like motif
(7, 9).
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The transcription factor NF-IL6 was discovered as an IL-1-inducible
factor that interacts with an IL-1-responsive element in the IL-6 gene
(19). NF-IL6 exists in all tissues at very low levels, but
is induced by lipopolysaccharides (LPS), IL-1, IL-6, or tumor necrosis
factor- (20). NF-IL6 belongs to the CCAAT
box/enhancer-binding protein (C/EBP) family with the consensus binding
sequence T(T/G)NNGNNAA(T/G) (21). Several signaling
pathways activate NF-IL6. These include serine and threonine
phosphorylation by mitogen- activated protein kinase, protein
kinase A, and a calcium/calmodulin-dependent kinase (20).
NF-IL6 regulates a variety of genes, including the genes for acute
phase proteins (22), c-Fos (23),
pregnancy-specific glycoprotein (24), inducible nitric
oxide synthase (25), prostaglandin H2
synthase-2 (26), and placental lactogen
(27).
The 5'-flanking region of the OTR gene contain response elements for NF-IL6 that are commonly found in cytokine-induced genes. However, the role of inflammatory cytokines in the induction of the OTR gene at the molecular level has not been investigated to date. We hypothesized that IL-1ß and IL-6 induce OTR gene expression in human myometrial cells and that this is mediated by NF-IL6 and cognate response elements in the 5'-flanking region of the OTR gene. Our specific aims were to investigate the ability of IL-1ß and IL-6 to induce OT mRNA synthesis in immortalized human myometrial cells, to demonstrate the presence of NF-IL6 in nuclear extracts of these cells, and to functionally characterize the 5'-flanking region of the OTR gene promoter.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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RPA
To investigate the effect of cytokine stimulation on OTR mRNA,
ULTR cells were treated with 10 ng/ml IL-1ß and 10 ng/ml IL-6
(Upstate Biotechnology, Inc., Lake Placid, NY) for varying
time intervals (1.5, 3, and 6 h). Preliminary studies using
concentrations from 0.1–100 ng/ml demonstrated maximal effectiveness
at the 10 or 100 ng/ml concentrations for both cytokines. Total RNA was
extracted from cells using TRIzol reagent (Life Technologies, Inc.). The DNA template for synthesis of the OTR riboprobe was
prepared from human decidual RNA by RT-PCR (Invitrogen,
Carlsbad, CA). A 237-bp fragment corresponding to a region extending
from the third to the fifth transmembrane domain was amplified and
subcloned into pCR-Script (Stratagene, La Jolla, CA) The
primers used were 5'-CTA CCT GCT GCT GCT CAT GTC-3' and 5'-AGC GTG ATC
CAT GTG ATG TAG G-3' (29). Human cyclophilin
(Ambion, Inc., Austin, TX) served as the internal
standard. Human (h) OTR (333 bp) and cyclophilin antisense riboprobes
were generated in a 10-µl reaction containing 1 x transcription
buffer (40 mM Tris-Cl, 8 mM
MgCl2, 2 mM spermidine, and 50
mM NaCl); 1.2 U/µl RNasin (Promega Corp.,
Madison, WI); 6 mM dithiothreitol (Promega Corp.); 0.5 mM each of ATP, GTP, and UTP; 100 µCi
[-32P]CTP (Amersham Pharmacia Biotech, Aylesbury, UK); 1 µg DNA template; and 17 U/µl T3
RNA polymerase (Promega Corp.). After incubation at 37 C
for 1 h, 6 µl RNase-free deoxyribonuclease I (10–50 x
103 U/ml; Roche Molecular Biochemicals, Mannheim, Germany) were added, followed by an
incubation at 37 C for 20 min. Labeled complementary RNA probe was
extracted by adding 100 µl 1 x TE (10 mM Tris, pH
7.4, and 1 mM EDTA), 4 µl carrier transfer RNA (tRNA; 50
µg/ml), and 150 µl Tris-saturated phenol-chloroform containing
isoamyl alcohol. The reaction was vortexed, spun down, ethanol
precipitated, and incubated at -20 C overnight. The labeled
complementary RNA was pelleted, dried at room temperature, resuspended
in 3 µl 1 x TE and 16 µl loading buffer (80% vol/vol
formamide; 1 mM EDTA, pH 8; 0.1% bromophenol blue; and
0.1% xylene cyanol), and purified electrophoretically on a prewarmed
6% denaturing polyacrylamide gel at 350 V in 1 x TBE (89
mM Tris, 89 mM boric acid, and 2 mM
EDTA, pH 8.0). After elution in 400 µl prewarmed buffer (2
M ammonium acetate, 1% SDS, and 25 µg/ml tRNA) at 37 C
for 3 h, the labeled probe was ethanol precipitated, dried at room
temperature, redissolved in 3 µl TE, and taken up in 100 µl
hybridization buffer [40 mM PIPES, pH 6.4; 0.4
M NaCl; 1 mM EDTA; and 80% (vol/vol)
formamide]. Total RNA (3–5 µg) from samples was ethanol
precipitated in presence of 40 µg tRNA. In each experiment tRNA alone
served as the negative control. Vacuum-dried precipitates were
redissolved in 2 µl 1 x TE and hybridized with each 3 x
105 cpm OTR and cyclophilin riboprobes in
hybridization buffer in 30 µl for at least 14 h at 55 C. Seven
hundred and fifty nanograms of RNase A and 300 U RNase T1 were added in
buffer containing 10 mM Tris-Cl, pH 7.5; 300 mM
NaCl; and 5 mM EDTA and incubated for 30 min at 30 C.
Addition of 100 µg proteinase K in the presence of 0.6% SDS for 20
min at 37 C removed RNases. After a phenol-chloroform extraction,
hybridized 32P-labeled RNA fragments were dried
at room temperature, dissolved in loading buffer, and electrophoresed
on a prewarmed 6% denaturing polyacrylamide gel. RNA bands were
detected by autoradiography. Their intensities were quantified using
the SCION IMAGE program (NIH, 1998, Scion Corp., Frederick, MD)
and corrected for cyclophilin mRNA. OTR densitometric values were
divided by those of cyclophilin measured in the same RNA preparations.
Data were analyzed using ANOVA and Tukey-Kramer multiple comparisons
test.
Preparation of nuclear extracts
ULTR cells were grown to 80–90% confluence and treated with 10
ng/ml IL-1ß and 100 ng/ml IL-6 for 0.25 and 1 h, respectively.
Cells were harvested, and nuclear extracts were prepared
(30). Briefly, myocyte monolayers were rinsed three times
with ice-cold PBS and scraped in PBS in 1.5-ml microfuge tubes. Cells
were pelleted by centrifugation at 1500 x g for 3 min.
Pellets were resuspended in 400 µl buffer A (10
mM HEPES, pH 7.9; 10 mM
KCl; 0.1 mM EGTA; 1 mM
dithiothreitol; and 1 mM
phenylmethylsulfonylfluoride) and swelled for 15 min at 4 C.
Twenty-five microliters of 10% Nonidet P-40 were added, and tubes were
vortexed. Homogenates were centrifuged 30 sec at 13,800 x
g in a microfuge. The nuclear pellets were resuspended in 50
µl ice-cold buffer C (20 mM HEPES, pH 7.9; 0.4
M NaCl; 1 mM EDTA; 1
mM EGTA; 1 mM
dithiothreitol; and 1 mM
phenylmethylsulfonylfluoride), and the extracts were vigorously rocked
at 4 C for 15 min. The nuclear extracts were then centrifuged for 5 min
at 13,800 x g in a microfuge at 4 C, and the
supernatant was used in the electrophoretic mobility shift assay
(EMSA).
EMSA
The EMSA was performed using a kit (Geneka, Montréal,
Canada) that was revalidated for our system. The DNA probe containing a
C/EBP consensus motif was 5'-end labeled with
[
-32P]ATP (NEN Life Science Products-DuPont, Boston, MA) and T4
polynucleotide kinase (Promega Corp.) and purified on a
Micro Spin G25 column. EMSA and supershift
assays were performed according to the manufacturer’s protocol
using 105 cpm DNA probe and 5 µg nuclear
extract. Nuclear extract from rat liver tissue served as a positive
control. The extract was electrophoresed on a precooled 5%
nondenaturing polyacrylamide gel in 1 x TGE buffer (6.06 g
Tris-base, 28.54 g glycine, and 0.78 g EDTA in 1l deionized water,
pH 8.5). Shifted and supershifted bands were detected by auto-
radiography.
Promoter constructs
The OTR promoter construct and its 5'-deletions were prepared by
PCR using selected sense/antisense primers. The complementary DNA
template (provided by Dr. T. Kimura, Osaka University, Medical School,
Osaka, Japan) ranged from approximately 3 kb upstream of the
transcription start site to the middle of the third intron. The first
transcriptional start site (7) was assigned +1. The
5'-end primers consisted of 20–22 nucleotides complementary to the
bottom strand of the template. Upstream of the matched sequence a
HindIII restriction site was attached flanked by 4
nucleotides. The sense primer sequences were ATC GAA GCT TGG CAG GCT
TGG TTC TAC AGG, ATC GAA GCT TCT GTA ATT TTC GAG CCG ATA G, ATC GAA GCT
TGG AAA CCC AGT CCT TGGCTA, and ATC GAA GCT TGC GCA GAC AAG CAG AAT
CAC. The 3'-end primer consisted of 20 nucleotides complementary to the
top strand, upstream of which was an XbaI restriction site
with 4 flanking nucleotides. Its sequence was ATC GTC TAG ACT GAG GCT
GCA CTA TCG CAC. All constructs had the same 3'-end, because the same
3'-end primer was used in each of the PCR reactions. DNA was amplified
in a 100-µl reaction consisting of 10 µl 10 x polymerase
buffer, 200 µM of each deoxy-NTP, 1.5
mM MgCl2, 0.2
µM of each of the primers, 2 ng complementary
DNA template, and 5 U platinum Taq DNA polymerase
(Life Technologies, Inc.). After denaturing the template
for 1 min at 94 C, DNA was amplified through 30 cycles for 1 min at 94
C, 1 min at 58 C, and 2 min at 72 C. A final extension step was
performed at 72 C for 6 min. PCR reactions were electrophoresed on a
1% agarose gel in TAE buffer (2 M Tris-HCl, 250
mM sodium acetate, and 1 M
EDTA) at 120 V and yielded the following products: a 1.31-kbp fragment
(-1203 bp/+108 bp), a 1.01-kbp fragment (-909 bp/+108 bp), an 830-bp
fragment (-722 bp/+108 bp), and a 511-bp fragment (-403 bp/+108 bp).
Bands of interest were excised with a scalpel, and DNA was eluted from
the gel using a kit (Promega Corp., Madison, WI).
The purified products were digested with
HindIII/XbaI and inserted into the
HindIII/XbaI polylinker restriction site upstream
of the chloramphenicol acetyltransferase (CAT) reporter gene in the
promoterless pCAT-Basic vector (Promega Corp.).
Transient transfections
The day before transfection, HeLa cells were plated into
six-well tissue culture plates and transfected at approximately 80%
confluence with 1 µg/well reporter construct using FuGENE6 reagent as
recommended by the supplier (FuGENE6, Roche Molecular Biochemicals). In all experiments 1 µg/well
pSV-ß-galactosidase vector (Promega Corp.) was
cotransfected and used as an internal standard. At 5 h
posttransfection, cells were treated with IL-1ß (10 ng/ml) or IL-6
(10 ng/ml), respectively, until lysis. At 48 h posttransfection,
cell lysates for CAT and ß-galactosidase (ß-gal) assays were
prepared with buffers supplied by the manufacturer according to the
protocol provided (Promega Corp.). Lysates were
microcentrifuged for 2 min at 4 C. CAT and ß-gal activities were
measured in supernatants according to the supplier’s protocol
(Promega Corp.). Briefly, CAT activity was determined by
liquid scintillation counting (LS5000TD, Beckman Coulter, Inc., Fullerton, CA) after 100 µl cell lysate were
incubated with 0.15 µCi [14C]chloramphenicol
(Amersham Pharmacia Biotech) and 25 µg
n-butyryl coenzyme A for 20 h at 37 C. ß-Gal activity
was determined by adding 50 µl cell lysate to 50 µl substrate
containing 2 x assay buffer (Promega Corp.),
incubating at 37 C until a faint yellow color developed, and measuring
absorbance at 405 nm in an enzyme-linked immunosorbent assay reader
(Molecular Devices, Menlo Park, CA) after the addition of
150 µl 1 M sodium carbonate.
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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. Using the RPA, we
detected a protected band for OTR at 237 bp as expected. In response to
both IL-1ß and IL-6, there was a significant decrease in OTR mRNA
within 3 h. After 6-h exposure to either IL-1ß or IL-6, OTR mRNA
levels decreased to approximately 25–30% of those at time zero.
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). The addition of anti-NF-IL6 antibody
created a supershift, confirming the identity of NF-IL6 in nuclear
extracts of both IL-1ß- and IL-6-stimulated and unstimulated ULTR
cells. This semiquantitative assay suggested an increase in NF-IL-6 in
the nuclear extracts of IL-1ß- or IL-6-treated ULTR cells compared
with control cells. There were no changes in NF-IL6 in the untreated
controls over the time of the incubation (data not shown).
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. The level of CAT
expression decreased significantly (P < 0.05) when the
sequence between -1203 and -909 was deleted. A further significant
decrease was observed when the sequence between -909 and -722 was
deleted (P < 0.05). The deletion of the sequence from
-722 to -403 had no further effect.
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). In response
to both IL-1ß and IL-6, CAT activity was similarly and significantly
(P < 0.05) decreased by IL-1ß and IL-6 treatment of
transfected HeLa cells transfected with promoter constructs containing
the -1203/+108 and -909/+108 fragments compared with that in
untreated cells. In cells transfected with constructs lacking the
-1203 to -722 sequence, neither IL-1ß nor IL-6 treatment showed a
significant effect on CAT activity.
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Down-regulation of OTR mRNA has further been reported by two
other groups. Maggi et al. (35) have shown that
interferon- decreases OTR mRNA in cultured human myometrial cells in
a time- and dose-dependent way. They found that OT mRNA levels are
maximally inhibited after 2–3 days treatment. Although all three
cytokines, IL-1ß, IL-6, and interferon-, have been reported to
decrease mRNA for OTRs in myometrial cells, the time frame is
different. This may suggest that the mechanisms leading to this
suppression are different or, again, the cell context is critical.
Phaneuf et al. (36) reported down-regulation of
OTR mRNA in human primary myometrial cells incubated with OT for
24 h. Such an agonist-induced decrease in receptor concentrations
is common for many receptor mRNAs, but occurs within different time
intervals depending on the cell type.
There are at least two potential mechanisms through which IL-1ß or IL-6 could decrease OTR mRNA levels in ULTR cells. The cytokines could induce a signaling cascade, leading to the transcriptional suppression of the OTR gene. This mechanism could involve NF-IL6 as a mediator. Alternatively, IL-1ß or IL-6 treatment of ULTR cells could activate factors in the cell that are responsible for mRNA destabilization. In this regard, the third intron of the OTR gene contains an element that may mediate transcriptional suppression of the hOTR gene (37). This region is hypomethylated in term myometrium, which highly expresses the OTR gene. In tissues not expressing OTRs, this region is hypermeth-ylated and binds nuclear proteins associated with suppression of OTR promoter activity. It is known that AU-rich sequences in the 3'-untranslated region mediate mRNA degradation by RNases (38, 39). Such AU-rich elements can be found in the 3'-untranslated region of the hOTR gene (40), and it is possible that the cytokines may influence this region to alter mRNA stability.
Using EMSA, we have shown that NF-IL6 is present in nuclear extracts from ULTR cells with or without cytokine treatment. This transcription factor is found in most tissues at very low levels, but can rapidly be induced by exposure to lipopolysaccharide or proinflammatory cytokines, including IL-1ß and IL-6 (20). Although there appeared to be an increase in NF-IL6 levels after cytokine treatment, we have not demonstrated that this was causally related to the changes in OTR mRNA concentrations. Further, we do not know whether the apparent increase in nuclear NF-IL6 was due to increased synthesis of NF-IL6 or to posttranslational modifications, such as phosphorylation of NF-IL6, that could increase its DNA-binding activity. The early onset of the apparent increase (by 15 min) may support the latter possibility. Finally, NF-IL6 may not directly bind to the OTR promoter, but may form complexes with other transcription factors. This possibility is supported by a recent study that provided a detailed analysis of approximately 3000 nucleotides of the 5'-flanking region of the OTR gene. Using EMSA, nuclear extracts of term human myometrium were compared with nuclear extracts from nonpregnant myometrium. In term myometrium, only two fragments were found to form specific DNA-protein complexes, and the involved cis elements did not include binding sites for NF-IL6 (41).
With respect to the effects of IL-1ß and IL-6, we functionally characterized the proximal 1.3 kb (-1203/+108) fragment of the hOTR gene promoter using 5'-deletion mutants transfected into HeLa cells that do not naturally express OTR mRNA. We demonstrated that the full length of this promoter fragment exhibits basal transcriptional activity in these cells. This is in agreement with other studies using OTR promoters from rat or human in different cell lines (9, 41, 42, 43). This basal transcriptional activity of the human OTR promoter occurs independently of whether cells naturally express OTR mRNA (43).
Deletion of the promoter fragment from -1203 to -909 caused a
significant reduction in transcription from the OTR promoter,
suggesting that this sequence had a net positive effect on
transcription. A similar conclusion was reached concerning the -909 to
-722 fragment. These findings are in keeping with the report by Hoare
et al. (9), who studied OTR regulation in the
mammary tumor cell line Hs578T. Our studies found no further decrease
in CAT activity with deletion of the -722 to -403 fragment. However,
Hoare et al. found an ets gene family-binding
site between -85 and -65 that was essential for basal and
serum-induced expression of the OTR gene (9). Using
supershift assays, they identified the transcription factor as
GABP/ß. Our studies would not have detected this regulatory
element, but do demonstrate that the -1203 to -722 fragment is
required for maximal promoter activity.
Contrary to our hypothesis, in response to treatment with
IL-1ß or IL-6, elements within the -1203/-722 region of the OTR
promoter mediate suppression of OTR gene promoter activity. The
apparent increase in NF-IL6 suggests that this may be the mediator that
negatively regulates transcription from the OTR promoter. However, the
signaling pathways of IL-1ß and IL-6 may involve synthesis or
activation of several transcription factors. The presence of B and
APRE binding sites in this region suggest NFB and APRF (also
known as STAT-3) as candidates mediating the actions of IL-1ß and
IL-6, as noted in the transcriptional regulation of acute phase
response genes (9, 44, 45). As there is an overall
positive effect of this promoter region on basal transcription, the
negative effects of cytokine treatment must involve important
interactions between positive and negative regulators. These
interactions could involve competition for DNA-binding sites, protein-
protein interactions, or indirect effects mediated through other
genes. Future studies will need to analyze the effects of specific
transcription factors in the context of the wide variety of potential
regulatory elements present in this promoter.
These experiments were undertaken to demonstrate that the increase in OTR was caused by the associated increases in the tissue and circulating concentrations of proinflammatory cytokines that occur in preterm or term labor in the presence and absence of infection (10, 11, 12, 13, 14). Our findings fail to support such a cause-effect relationship. If the increased cytokine concentrations play a role in stimulating parturition, it is probably through mechanisms other than direct stimulation of myometrial OTR. A potential mechanism would be the well described cytokine-induced stimulation of PGH2 synthase, the rate- limiting enzyme in PG synthesis (26, 32, 46).
In summary, we have demonstrated that IL-1ß and IL-6 treatment of immortalized human myometrial cells results in a significant decrease in OTR mRNA within a few hours of treatment. We have also shown that the ubiquitous transcription factor NF-IL6 is present at low levels in these cells and appears to be increased by IL-1ß and IL-6 treatment. Furthermore, we have demonstrated that the 5'-flanking region of the OTR gene is functional when transfected into HeLa cells. The presence of the -1203 to -722 fragment of this promoter is essential for full activity. Treatment of transfected HeLa cells with either IL-1ß or IL-6 decreased promoter activity of the promoter-reporter constructs, an effect dependent on the presence of the -1203 to -722 fragment. Taking these findings together, we conclude that IL-1ß and IL-6 may be involved in transcriptional regulation of the OTR gene. The promoter region from -1203 to -722 contains both positive and negative elements. The net effect is dependent on the transcription factors present and the milieu of the cell. A more detailed characterization of the -1203/-722 region of the OTR promoter and identification of trans-acting factors may provide valuable information regarding the regulation of human myometrial activation.
Received October 3, 2000.
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References |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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q/11. Endocrinology 136:1509–1515[Abstract]
/ß binding site
involved in the induction of oxytocin receptor gene expression in human
breast cancer cells. Potentiation by c-Fos/c-Jun. Endocrinology 140:2268–2279B
in cytokine gene regulation. Adv Immunol 65:1–47[Medline]
downregulates expression of the
oxytocin receptor in cultured human myometrial cells. Am J Physiol
271:E840–E846
B
mediates interleukin-1ß-induced expression of cyclooxygenase-2 in
human myometrial cells. Am J Obstet Gynecol 181:359–366[CrossRef][Medline]
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Y. Ikoma, S. Nomura, T. Ito, Y. Katsumata, M. Nakata, K. Iwanaga, M. Okada, F. Kikkawa, K. Tamakoshi, T. Nagasaka, et al. Interleukin-1{beta} stimulates placental leucine aminopeptidase/oxytocinase expression in BeWo choriocarcinoma cells Mol. Hum. Reprod., February 1, 2003; 9(2): 103 - 110. [Abstract] [Full Text] [PDF]
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Y.-J. Jeng, S. L. Soloff, G. D. Anderson, and M. S. Soloff Regulation of Oxytocin Receptor Expression in Cultured Human Myometrial Cells by Fetal Bovine Serum and Lysophospholipids Endocrinology, January 1, 2003; 144(1): 61 - 68. [Abstract] [Full Text] [PDF]
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 P. Cassoni, A. Sapino, S. Deaglio, B. Bussolati, M. Volante, L. Munaron, A. Albini, A. Torrisi, and G. Bussolati Oxytocin Is a Growth Factor for Kaposi's Sarcoma Cells: Evidence of Endocrine-Immunological Cross-Talk Cancer Res., April 1, 2002; 62(8): 2406 - 2413. [Abstract] [Full Text] [PDF]
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H. Helmer, U. Tretzmuller, M. Brunbauer, A. Kaider, P. Husslein, and M. Knofler Production of Oxytocin Receptor and Cytokines in Primary Uterine Smooth Muscle Cells Cultivated Under Inflammatory Conditions Reproductive Sciences, January 1, 2002; 9(1): 15 - 21. [Abstract] [PDF]
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B. F. Mitchell and B. Schmid Oxytocin and its Receptor in the Process of Parturition Reproductive Sciences, May 1, 2001; 8(3): 122 - 133. [Abstract] [PDF]
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G. Bussolati and P. Cassoni Editorial: The Oxytocin/Oxytocin Receptor System--Expect the Unexpected Endocrinology, April 1, 2001; 142(4): 1377 - 1379. [Full Text]
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