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Varley A, Koschinski A, Johnson MR, Zaccolo M. cAMP Compartmentalisation in Human Myometrial Cells. Cells 2023; 12:718. [PMID: 36899855 PMCID: PMC10001376 DOI: 10.3390/cells12050718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/12/2023] Open
Abstract
Preterm birth is the leading cause of childhood mortality and morbidity. A better understanding of the processes that drive the onset of human labour is essential to reduce the adverse perinatal outcomes associated with dysfunctional labour. Beta-mimetics, which activate the myometrial cyclic adenosine monophosphate (cAMP) system, successfully delay preterm labour, suggesting a key role for cAMP in the control of myometrial contractility; however, the mechanisms underpinning this regulation are incompletely understood. Here we used genetically encoded cAMP reporters to investigate cAMP signalling in human myometrial smooth muscle cells at the subcellular level. We found significant differences in the dynamics of the cAMP response in the cytosol and at the plasmalemma upon stimulation with catecholamines or prostaglandins, indicating compartment-specific handling of cAMP signals. Our analysis uncovered significant disparities in the amplitude, kinetics, and regulation of cAMP signals in primary myometrial cells obtained from pregnant donors compared with a myometrial cell line and found marked response variability between donors. We also found that in vitro passaging of primary myometrial cells had a profound impact on cAMP signalling. Our findings highlight the importance of cell model choice and culture conditions when studying cAMP signalling in myometrial cells and we provide new insights into the spatial and temporal dynamics of cAMP in the human myometrium.
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Affiliation(s)
- Alice Varley
- Department of Metabolism, Digestion and Reproduction, Imperial College London, Academic Department of Obstetrics & Gynaecology, Level 3, Chelsea & Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK
| | - Andreas Koschinski
- Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Sherrington Road, Oxford OX1 3PT, UK
| | - Mark R. Johnson
- Department of Metabolism, Digestion and Reproduction, Imperial College London, Academic Department of Obstetrics & Gynaecology, Level 3, Chelsea & Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Sherrington Road, Oxford OX1 3PT, UK
- Oxford NIHR Biomedical Research Centre, Oxford OX4 2PG, UK
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Hromadnikova I, Kotlabova K, Krofta L. Novel First-Trimester Prediction Model for Any Type of Preterm Birth Occurring before 37 Gestational Weeks in the Absence of Other Pregnancy-Related Complications Based on Cardiovascular Disease-Associated MicroRNAs and Basic Maternal Clinical Characteristics. Biomedicines 2022; 10:biomedicines10102591. [PMID: 36289853 PMCID: PMC9599357 DOI: 10.3390/biomedicines10102591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/06/2022] [Accepted: 10/12/2022] [Indexed: 11/16/2022] Open
Abstract
The goal of the study was to establish an efficient first-trimester predictive model for any type of preterm birth before 37 gestational weeks (spontaneous preterm birth (PTB) or preterm prelabor rupture of membranes (PPROM)) in the absence of other pregnancy-related complications, such as gestational hypertension, preeclampsia, fetal growth restriction, or small for gestational age. The retrospective study was performed in the period from 11/2012 to 3/2020. Peripheral blood samples were collected from 6440 Caucasian individuals involving 41 PTB and 65 PPROM singleton pregnancies. A control group with 80 singleton term pregnancies was selected on the basis of equal sample-storage time. A combination of only six microRNAs (miR-16-5p, miR-21-5p, miR-24-3p, miR-133a-3p, miR-155-5p, and miR-210-3p; AUC 0.812, p < 0.001, 70.75% sensitivity, 78.75% specificity, cut-off > 0.652) could predict preterm delivery before 37 gestational weeks in early stages of gestation in 52.83% of pregnancies with a 10.0% FPR. This predictive model for preterm birth based on aberrant microRNA expression profile was further improved via implementation of maternal clinical characteristics (maternal age and BMI at early stages of gestation, infertility treatment with assisted reproductive technology, occurrence of preterm delivery before 37 gestational weeks in previous pregnancy(ies), and presence of any kind of autoimmune disease (rheumatoid arthritis, systemic lupus erythematosus, antiphospholipid syndrome, type 1 diabetes mellitus, or other autoimmune disease)). With this model, 69.81% of pregnancies destined to deliver before 37 gestational weeks were identified with a 10.0% FPR at early stages of gestation. When other clinical variables as well as those mentioned above—such as positive first-trimester screening for early preeclampsia with onset before 34 gestational weeks and/or fetal growth restriction with onset before 37 gestational weeks using the Fetal Medicine Foundation algorithm, as well as positive first-trimester screening for spontaneous preterm birth with onset before 34 gestational weeks using the Fetal Medicine Foundation algorithm—were added to the predictive model for preterm birth, the predictive power was even slightly increased to 71.70% with a 10.0% FPR. Nevertheless, we prefer to keep the first-trimester screening for any type of preterm birth occurring before 37 gestational weeks in the absence of other pregnancy-related complications as simple as possible.
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Affiliation(s)
- Ilona Hromadnikova
- Department of Molecular Biology and Cell Pathology, Third Faculty of Medicine, Charles University, 10000 Prague, Czech Republic
- Correspondence: ; Tel.: +420-296511336
| | - Katerina Kotlabova
- Department of Molecular Biology and Cell Pathology, Third Faculty of Medicine, Charles University, 10000 Prague, Czech Republic
| | - Ladislav Krofta
- Institute for the Care of the Mother and Child, Third Faculty of Medicine, Charles University, 14700 Prague, Czech Republic
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Histone Deacetylase Inhibitors: Providing New Insights and Therapeutic Avenues for Unlocking Human Birth. Reprod Sci 2021; 29:3134-3146. [PMID: 34713433 DOI: 10.1007/s43032-021-00778-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/19/2021] [Indexed: 02/07/2023]
Abstract
The pregnant uterus remains relaxed throughout fetal gestation before transforming to a contractile phenotype at term to facilitate birth. Despite ongoing progress, the precise mechanisms that regulate this phenotypic transformation are not yet understood. This knowledge gap limits our understanding of how dysregulation of uterine smooth muscle biology contributes to life-threatening obstetric complications, including preterm birth, and hampers our ability to develop effective therapeutic intervention strategies. Protein acetylation plays a vital role in regulating protein structure, function, and subcellular localization, as well as gene transcription availability through regulating chromatin condensation. Histone deacetylase inhibitors (HDACis) are a class of compounds that block the removal of acetyl functional groups from proteins and, as such, have profound effects on important cellular events, including phenotypic transformation. A large body of data now demonstrates that HDACis have profound effects on pregnant human myometrium. Studies to date show that HDACis operate through both genomic and non-genomic mechanisms to affect myometrial function and phenotype. Interestingly, the effects of HDACis on pregnant myometrium are largely "pro-relaxation," including the direct inhibition of contractile machinery as well as repression of pro-labor genes. The "dual action" effects of HDACis make them a powerful tool for unlocking the regulatory processes that underpin myometrial phenotypic transformation and raises prospects of their therapeutic applications. Here, we review the new insights into human myometrial biology that have garnered through the application of HDACis and explore their potential therapeutic application toward the development of novel preterm birth prevention strategies.
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Lai PF, Young RC, Tribe RM, Johnson MR. Evaluating aminophylline and progesterone combination treatment to modulate contractility and labor-related proteins in pregnant human myometrial tissues. Pharmacol Res Perspect 2021; 9:e00818. [PMID: 34223706 PMCID: PMC8256431 DOI: 10.1002/prp2.818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 05/19/2021] [Indexed: 12/26/2022] Open
Abstract
Progesterone (P4) and cyclic adenosine monophosphate (cAMP) are regarded as pro-quiescent factors that suppress uterine contractions during pregnancy. We previously used human primary cells in vitro and mice in vivo to demonstrate that simultaneously enhancing myometrial P4 and cAMP levels may reduce inflammation-associated preterm labor. Here, we assessed whether aminophylline (Ami; phosphodiesterase inhibitor) and P4 can reduce myometrial contractility and contraction-associated proteins (CAPs) better together than individually; both agents are clinically used drugs. Myometrial tissues from pregnant non-laboring women were treated ex vivo with Ami acutely (while spontaneous contracting) or throughout 24-h tissue culture (±P4); isometric tension measurements, PKA assays, and Western blotting were used to assess tissue contractility, cAMP action, and inflammation. Acute (1 h) treatment with 250 and 750 μM Ami reduced contractions by 50% and 84%, respectively, which was not associated with a directly proportional increase in whole tissue PKA activity. Sustained myometrial relaxation was observed during 24-h tissue culture with 750 μM Ami, which did not require P4 nor reduce CAPs. COX-2 protein can be reduced by 300 nM P4 but this did not equate to myometrial relaxation. Ami (250 μM) and P4 (100 and 300 nM) co-treatment did not prevent oxytocin-augmented contractions nor reduce CAPs during interleukin-1β stimulation. Overall, Ami and P4 co-treatment did not suppress myometrial contractions more than either agent alone, which may be attributed to low specificity and efficacy of Ami; cAMP and P4 action at in utero neighboring reproductive tissues during pregnancy should also be considered.
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Affiliation(s)
- Pei F. Lai
- Division of Reproductive and Developmental BiologyDepartment of Metabolism, Digestion and ReproductionImperial College LondonLondonUK
| | | | - Rachel M. Tribe
- Department of Women and Children's HealthSchool of Life Course SciencesKing's College LondonLondonUK
| | - Mark R. Johnson
- Division of Reproductive and Developmental BiologyDepartment of Metabolism, Digestion and ReproductionImperial College LondonLondonUK
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Yulia A, Singh N, Varley AJ, Lei K, Markovic D, Sooranna SR, Johnson MR. PKA and AKIP1 interact to mediate cAMP-driven COX-2 expression: A potentially pivotal interaction in preterm and term labour. PLoS One 2021; 16:e0252720. [PMID: 34166397 PMCID: PMC8224895 DOI: 10.1371/journal.pone.0252720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 05/21/2021] [Indexed: 11/21/2022] Open
Abstract
Previously, we showed that cAMP increased COX-2 expression in myometrial cells via MAPK. Here, we have extended these observations, using primary myometrial cell cultures to show that the cAMP agonist, forskolin, enhances IL-1β-driven COX-2 expression. We then explored the role of A-kinase interacting protein (AKIP1), which modulates the effect of PKA on p65 activation. AKIP1 knockdown reversed the effect of forskolin, such that its addition inhibited IL-1β-induced COX-2 mRNA expression and reduced the IL-1β-induced increase in nuclear levels of p65 and c-jun. Forskolin alone and with IL-1β increased IκBα mRNA expression suggesting that in the context of inflammation and in the presence of AKIP1, cAMP enhances p65 activation. AKIP1 knockdown reversed these changes. Interestingly, AKIP1 knockdown had minimal effect on the ability of forskolin to repress either basal OTR expression or IL-1β-stimulated OTR mRNA expression. AKIP1 was up-regulated by IL-1β, but not stretch and was repressed by cAMP. The mRNA expression of AKIP1 increased in early labour in tandem with an increase in COX-2 mRNA and protein. AKIP1 protein levels were also increased with inflammation and stretch-induced preterm labour. Our results identify a second important cAMP effector-switch occurring at term in human myometrium and suggest that a hitherto unrecognized interaction may exist between AKIP1, NFκB and AP-1. These data add to the proposition that cAMP acts as a key regulator of human myometrial contractility.
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Affiliation(s)
- Angela Yulia
- Chelsea and Westminster Hospital, London, United Kingdom
- Institute of Reproductive and Developmental Biology, London, United Kingdom
- * E-mail:
| | - Natasha Singh
- Chelsea and Westminster Hospital, London, United Kingdom
- Institute of Reproductive and Developmental Biology, London, United Kingdom
| | - Alice J. Varley
- Chelsea and Westminster Hospital, London, United Kingdom
- Institute of Reproductive and Developmental Biology, London, United Kingdom
| | - Kaiyu Lei
- Chelsea and Westminster Hospital, London, United Kingdom
- Institute of Reproductive and Developmental Biology, London, United Kingdom
| | | | - Suren R. Sooranna
- Chelsea and Westminster Hospital, London, United Kingdom
- Institute of Reproductive and Developmental Biology, London, United Kingdom
| | - Mark R. Johnson
- Chelsea and Westminster Hospital, London, United Kingdom
- Institute of Reproductive and Developmental Biology, London, United Kingdom
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Transcription factors regulated by cAMP in smooth muscle of the myometrium at human parturition. Biochem Soc Trans 2021; 49:997-1011. [PMID: 33860781 PMCID: PMC8106496 DOI: 10.1042/bst20201173] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 12/11/2022]
Abstract
Cyclic adenosine monophosphate (cAMP) contributes to maintenance of a quiescent (relaxed) state in the myometrium (i.e. uterine smooth muscle) during pregnancy, which most commonly has been attributed to activation of protein kinase A (PKA). PKA-mediated phosphorylation of cytosolic contractile apparatus components in myometrial smooth muscle cells (mSMCs) are known to promote relaxation. Additionally, PKA also regulates nuclear transcription factor (TF) activity to control expression of genes important to the labour process; these are mostly involved in actin-myosin interactions, cell-to-cell connectivity and inflammation, all of which influence mSMC transition from a quiescent to a contractile (pro-labour) phenotype. This review focuses on the evidence that cAMP modulates the activity of TFs linked to pro-labour gene expression, predominantly cAMP response element (CRE) binding TFs, nuclear factor κB (NF-κB), activator protein 1 (AP-1) family and progesterone receptors (PRs). This review also considers the more recently described exchange protein directly activated by cAMP (EPAC) that may oppose the pro-quiescent effects of PKA, as well as explores findings from other cell types that have the potential to be of novel relevance to cAMP action on TF function in the myometrium.
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Yulia A, Varley AJ, Singh N, Lei K, Tribe RM, Johnson MR. The interaction between protein kinase A and progesterone on basal and inflammation-induced myometrial oxytocin receptor expression. PLoS One 2020; 15:e0239937. [PMID: 33259490 PMCID: PMC7707466 DOI: 10.1371/journal.pone.0239937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 09/15/2020] [Indexed: 11/21/2022] Open
Abstract
Our previous work has shown myometrial PKA activity declines in term and twin-preterm labour in association with an increase in the expression of the oxytocin receptor (OTR). Here we investigate the action of cAMP/PKA in basal conditions, with the addition of progesterone (P4) and/or IL-1β to understand how cAMP/PKA acts to maintain pregnancy and whether the combination of cAMP and P4 would be a viable therapeutic combination for the prevention of preterm labour (PTL). Further, given that we have previously found that cAMP enhances P4 action we wanted to test the hypothesis that changes in the cAMP effector system are responsible for the functional withdrawal of myometrial P4 action. Myometrial cells were grown from biopsies obtained from women at the time of elective Caesarean section before the onset of labour. The addition of forskolin, an adenylyl cyclase activator, repressed basal OTR mRNA levels at all doses and P4 only enhanced this effect at its highest dose. Forskolin repressed the IL-1β-induced increase in OTR mRNA and protein levels in a PKA-dependent fashion and repressed IL-1β-activation and nuclear transfer of NFκB and AP-1. P4 had similar effects and the combination P4 and forskolin had greater effects on OTR and NFκB than forskolin alone. While PKA knockdown had no effect on the ability of P4 to repress IL-1β-induced OTR expression it reversed the repressive effect of the combination of P4 and forskolin and resulted in a greater increase than observed with IL-1β alone. These studies suggest that cAMP acts via PKA to repress inflammation-driven OTR expression, but that when PKA activity is reduced, the combination of cAMP and P4 actually enhances the OTR response to inflammation, promoting the onset of labour and suggesting that changes in the cAMP effector system can induce a functional P4 withdrawal.
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Affiliation(s)
- Angela Yulia
- Institute of Reproductive and Developmental Biology, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, United Kingdom
| | - Alice J. Varley
- Institute of Reproductive and Developmental Biology, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, United Kingdom
| | - Natasha Singh
- Institute of Reproductive and Developmental Biology, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, United Kingdom
| | - Kaiyu Lei
- Institute of Reproductive and Developmental Biology, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, United Kingdom
| | - Rachel M. Tribe
- Department of Women and Children’s Health, School of Life Course Sciences, Kings College London, London, United Kingdom
| | - Mark R. Johnson
- Institute of Reproductive and Developmental Biology, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, United Kingdom
- * E-mail:
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Changes in cAMP effector predominance are associated with increased oxytocin receptor expression in twin but not infection-associated or idiopathic preterm labour. PLoS One 2020; 15:e0240325. [PMID: 33253216 PMCID: PMC7703985 DOI: 10.1371/journal.pone.0240325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 09/24/2020] [Indexed: 11/19/2022] Open
Abstract
We previously reported that at term pregnancy, a decline in myometrial protein kinase A (PKA) activity leads to an exchange protein activated by cyclic AMP (Epac1)-dependent increase in oxytocin receptor (OTR) expression, promoting the onset of labour. Here, we studied the changes in the cyclic adenosine monophosphate (cAMP) effector system present in different phenotypes of preterm labour (PTL). Myometrial biopsies obtained from women with phenotypically distinct forms of PTL and the levels of PKA and OTR were examined. Although we found similar changes in the cAMP effector pathway in all forms of PTL, only in the case of twin PTL (T-PTL) was myometrial OTR levels increased in association with these results. Although there were several changes in the mRNA levels of components of the cAMP synthetic pathway, the total myometrial cAMP levels did not change with the onset of any subtype of PTL. With regards to the expression of cAMP-responsive genes, we found that the mRNA levels of 4 of the 5 cAMP-down-regulated genes were increased in T-PTL, similar to our findings in term labour. These data signify that although changes in the cAMP effector system were common to all forms of PTL, only in T-PTL were OTR levels increased. Similarly, the mRNA levels of cAMP-repressed genes were only increased in T-PTL supporting the concept that the decline in PKA levels influences myometrial function driving the onset of T-PTL.
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Butler TA, Paul JW, Smith R. Non-conventional signalling in human myometrium by conventional pathways: looking back for a synergistic future. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2019.11.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Yulia A, Singh N, Lei K, Sooranna SR, Johnson MR. Cyclic AMP Effectors Regulate Myometrial Oxytocin Receptor Expression. Endocrinology 2016; 157:4411-4422. [PMID: 27673556 DOI: 10.1210/en.2016-1514] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The factors that initiate human labor are poorly understood. We have tested the hypothesis that a decline in cAMP/protein kinase A (PKA) function leads to the onset of labor. Initially, we identified myometrial cAMP/PKA-responsive genes (six up-regulated and five down-regulated genes) and assessed their expression in myometrial samples taken from different stages of pregnancy and labor. We found that the oxytocin receptor (OTR) was one of the cAMP-repressed genes, and, given the importance of OTR in the labor process, we studied the mechanisms involved in greater detail using small interfering RNA, chemical agonists, and antagonists of the cAMP effectors. We found that cAMP-repressed genes, including OTR, increased with the onset of labor. Our in vitro studies showed that cAMP acting via PKA reduced OTR expression but that in the absence of PKA, cAMP acts via exchange protein activated by cAMP (EPAC) to increase OTR expression. In early labor myometrial samples, PKA levels and activity declined and Epac1 levels increased, perhaps accounting for the increase in myometrial OTR mRNA and protein levels at this time. In vitro exposure of myometrial cells to stretch and IL-1β increased OTR levels and reduced basal and forskolin-stimulated cAMP and PKA activity, as judged by phospho-cAMP response element-binding protein levels, but neither stretch nor IL-1β had any effect on PKA or EPAC1 levels. In summary, there is a reduction in the activity of the cAMP/PKA pathway with the onset of human labor potentially playing a critical role in regulating OTR expression and the transition from myometrial quiescence to activation.
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Affiliation(s)
- Angela Yulia
- Chelsea and Westminster Hospital (A.Y., N.S., K.L., S.R.S., M.R.J.), London SW10 9NH, United Kingdom; and Institute of Reproductive and Developmental Biology (A.Y., N.S., K.L., S.R.S., M.R.J.), London W12 0NN, United Kingdom
| | - Natasha Singh
- Chelsea and Westminster Hospital (A.Y., N.S., K.L., S.R.S., M.R.J.), London SW10 9NH, United Kingdom; and Institute of Reproductive and Developmental Biology (A.Y., N.S., K.L., S.R.S., M.R.J.), London W12 0NN, United Kingdom
| | - Kaiyu Lei
- Chelsea and Westminster Hospital (A.Y., N.S., K.L., S.R.S., M.R.J.), London SW10 9NH, United Kingdom; and Institute of Reproductive and Developmental Biology (A.Y., N.S., K.L., S.R.S., M.R.J.), London W12 0NN, United Kingdom
| | - Suren R Sooranna
- Chelsea and Westminster Hospital (A.Y., N.S., K.L., S.R.S., M.R.J.), London SW10 9NH, United Kingdom; and Institute of Reproductive and Developmental Biology (A.Y., N.S., K.L., S.R.S., M.R.J.), London W12 0NN, United Kingdom
| | - Mark R Johnson
- Chelsea and Westminster Hospital (A.Y., N.S., K.L., S.R.S., M.R.J.), London SW10 9NH, United Kingdom; and Institute of Reproductive and Developmental Biology (A.Y., N.S., K.L., S.R.S., M.R.J.), London W12 0NN, United Kingdom
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Ku CY, Word RA, Sanborn BM. Differential Expression of Protein Kinase A, AKAP 79, and PP2B in Pregnant Human Myometrial Membranes Prior to and During Labor. ACTA ACUST UNITED AC 2016; 12:421-7. [PMID: 15914039 DOI: 10.1016/j.jsgi.2005.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We have previously shown that the association of protein kinase A (PKA) with purified myometrial plasma membrane declined at the end of pregnancy in the rat. This study was designed to determine if a similar decline in PKA occurred in pregnant human myometrium. METHODS Myometrial plasma membranes were isolated from lower uterine segment tissues from not-in-labor (NIL) and in-labor (IL) patients undergoing cesarean delivery. Membrane proteins were subjected to Western blot analysis to detect PKA-catalytic (PKA-cat) and PKA-regulatory (PKA-reg) subunits, the PKA binding protein A-kinase anchoring protein 79 (AKAP79), protein phosphatase 2B (PP2B), and Galphaq, a guanosine triphosphate (GTP)-binding protein. Protein levels were expressed relative to caveolin-1, which was invariant between the two groups. RESULTS The amount of PKA-cat, PKA-reg, AKAP79, and PP2B in plasma membranes from myometrium of women in early labor decreased significantly compared with that in tissues from women not in labor. In contrast, Galphaq did not change. All proteins were localized to myometrial smooth muscle cells by immunohistochemistry. CONCLUSIONS Expression of PKA, PP2B, and AKAP79 is consistent with the presence of a functional AKAP-mediated signaling complex in pregnant human myometrial membranes. A small but significant decrease in PKA, AKAP79, and PP2B in myometrial tissues from women in labor may contribute to a decrease in negative feedback on and enhancement of contractant signals at term.
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Affiliation(s)
- Chun-Ying Ku
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
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Lai PF, Tribe RM, Johnson MR. Differential impact of acute and prolonged cAMP agonist exposure on protein kinase A activation and human myometrium contractile activity. J Physiol 2016; 594:6369-6393. [PMID: 27328735 DOI: 10.1113/jp272320] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/30/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Over 15 million babies are born prematurely each year with approximately 1 million of these babies dying as a direct result of preterm delivery. β2 -Adrenoreceptor agonists that act via cAMP can reduce uterine contractions to delay preterm labour, but their ability to repress uterine contractions lasts ≤ 48 h and their use does not improve neonatal outcomes. Previous research has suggested that cAMP inhibits myometrial contractions via protein kinase A (PKA) activation, but this has yet to be demonstrated with PKA-specific agonists. We investigated the role of PKA in mediating cAMP-induced human myometrial relaxation, and the impact of prolonged cAMP elevation on myometrial contractility. Our findings suggest that PKA is not the sole mediator of cAMP-induced myometrial relaxation and that prolonged prophylactic elevation of cAMP alone is unlikely to prevent preterm labour (PTL). ABSTRACT Acute cAMP elevation inhibits myometrial contractility, but the mechanisms responsible are not fully elucidated and the long-term effects are uncertain. Both need to be defined in pregnant human myometrium before the therapeutic potential of cAMP-elevating agents in the prevention of preterm labour can be realised. In the present study, we tested the hypotheses that PKA activity is necessary for cAMP-induced myometrial relaxation, and that prolonged cAMP elevation can prevent myometrial contractions. Myometrial tissues obtained from term, pre-labour elective Caesarean sections were exposed to receptor-independent cAMP agonists to determine the relationship between myometrial contractility (spontaneous and oxytocin-induced), PKA activity, HSP20 phosphorylation and expression of contraction-associated and cAMP signalling proteins. Acute (1 h) application of cAMP agonists promoted myometrial relaxation, but this was weakly related to PKA activation. A PKA-specific activator, 6-Bnz-cAMP, increased PKA activity (6.8 ± 2.0 mean fold versus vehicle; P = 0.0313) without inducing myometrial relaxation. Spontaneous myometrial contractility declined after 24 h but was less marked when tissues were constantly exposed to cAMP agonists, especially for 8-bromo-cAMP (4.3 ± 1.2 mean fold versus vehicle; P = 0.0043); this was associated with changes to calponin, cofilin and HSP20 phosphorylated/total protein levels. Oxytocin-induced contractions were unaffected by pre-incubation with cAMP agonists despite treatments being able to enhance PKA activity and HSP20 phosphorylation. These data suggest that cAMP-induced myometrial relaxation is not solely dependent on PKA activity and the ability of cAMP agonists to repress myometrial contractility is lost with prolonged exposure. We conclude that cAMP agonist treatment alone may not prevent preterm labour.
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Affiliation(s)
- Pei F Lai
- Academic Department of Obstetrics & Gynaecology, Imperial College London, London, SW10 9NH, UK
| | - Rachel M Tribe
- Division of Women's Health, Kings College London and Women's Health Academic Centre, Kings Health Partners, London, SE1 7EH, UK
| | - Mark R Johnson
- Academic Department of Obstetrics & Gynaecology, Imperial College London, London, SW10 9NH, UK.
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Genetic association of AKAP10 gene polymorphism with reduced risk of preterm birth. J Perinatol 2015; 35:700-4. [PMID: 26110499 DOI: 10.1038/jp.2015.68] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 03/19/2015] [Accepted: 04/14/2015] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Preterm birth (PTB) is a multifactorial complication in which genetic and environmental factors contribute to the phenotype. The AKAP10 protein encoded by AKAP10 gene has a vital role in the maintenance of myometrial quiescence and pregnancy. This study aimed to investigate whether polymorphisms in the AKAP10 gene are associated with the risk of PTB. STUDY DESIGN A total of 664 women (132 preterm and 532 term) with spontaneous singleton deliveries were genotyped for AKAP10 polymorphisms (rs119672, rs203462 and rs169412) using Sequenom MassARRAY platform. RESULT A significant association was observed between the CC and AC genotypes of AKAP10 rs169412 with reduced risk of PTB (CC: adjusted odds ratio (OR) 2.95, 95% confidence interval (CI): 1.23-7.09, P=0.016. AC: adjusted OR 3.46, 95% CI: 1.38-8.68, P=0.008), respectively. Following stratification by ethnicity, a significant association was observed between the AC and CC genotypes of rs169412 and term birth in the Malay ethnic subgroup. (CC: OR 2.9, 95% CI: 1.01-8.59, P=0.041. AC: OR 3.14, 95% CI: 1.04-9.54, P=0.043). A significant association was also observed between the CT genotypes of AKAP10 rs119672 with reduced risk of PTB deliveries (CT: OR 3.2, 95% CI: 1.06-9.76 P=0.007, TT: OR 2.8, 0.98-8.34, P =.0.015) Alternatively, there was no association between AKAP10 rs169412 and rs119672 polymorphisms with PTB in the Indians and Chinese ethnic groups. CONCLUSION This study indicates a significant association between the AKAP10 polymorphisms and reduced risk of PTB in the Malays. This demonstrates the potential role of AKAP10 polymorphisms in preterm complications.
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Smith R, Imtiaz M, Banney D, Paul JW, Young RC. Why the heart is like an orchestra and the uterus is like a soccer crowd. Am J Obstet Gynecol 2015; 213:181-5. [PMID: 26116101 DOI: 10.1016/j.ajog.2015.06.040] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/01/2015] [Accepted: 06/16/2015] [Indexed: 12/22/2022]
Abstract
The human uterus has no pacemaker or motor innervation, yet develops rhythmic, powerful contractions that increase intrauterine pressure to dilate the cervix and force the fetus through the pelvis. To achieve the synchronous contractions required for labor, the muscle cells of the uterus act as independent oscillators that become increasingly coupled by gap junctions toward the end of pregnancy. The oscillations are facilitated by changes in resting membrane potential that occur as pregnancy progresses. Reductions of potassium channels in the myocyte membranes in late pregnancy prolong myocyte action potentials, further facilitating transmission of signals and recruitment of neighboring myocytes. Late in pregnancy prostaglandin production increases leading to increased myocyte excitability. Also late in pregnancy myocyte actin polymerizes allowing actin-myosin interactions that generate force, following myocyte depolarization, calcium entry, and activation of myosin kinase. Labor occurs as a consequence of the combination of increased myocyte to myocyte connectivity, increased depolarizations that last longer, and activated intracellular contractile machinery. During labor the synchronous contractions of muscle cells raise intrauterine pressure to dilate the cervix in a process distinct from peristalsis. The synchronous contractions occur in a progressively larger region of the uterine wall. As the size of the region increases with increasing connectivity, the contraction of that larger area leads to an increase in intrauterine pressure. The resulting increased wall tension causes myocyte depolarization in other parts of the uterus, generating widespread synchronous activity and increased force as more linked regions are recruited into the contraction. The emergent behavior of the uterus has parallels in the behavior of crowds at soccer matches that sing together without a conductor. This contrasts with the behavior of the heart where sequential contractions are regulated by a pacemaker in a similar way to the actions of a conductor and an orchestra.
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15
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Diminished hERG K+ channel activity facilitates strong human labour contractions but is dysregulated in obese women. Nat Commun 2014; 5:4108. [PMID: 24937480 DOI: 10.1038/ncomms5108] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/13/2014] [Indexed: 01/01/2023] Open
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16
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Markovic D, Bari MF, Lu B, Vatish M, Grammatopoulos DK. Corticotropin-releasing hormone interacts with interleukin-1β to regulate prostaglandin H synthase-2 expression in human myometrium during pregnancy and labor. J Clin Endocrinol Metab 2013; 98:2864-75. [PMID: 23666959 PMCID: PMC3877764 DOI: 10.1210/jc.2013-1094] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
CONTEXT The onset of labor appears to involve the activation of myometrial inflammatory pathways, and transcription factors such as nuclear factor-κB (NF-κB) control expression of the contraction-associated proteins required to induce a procontractile phenotype. These responses might involve CRH, which integrates immune and neuroendocrine systems. OBJECTIVES In human myometrium we investigated cyclooxygenase 2 (PGHS2) expression and regulation by CRH and the proinflammatory cytokine IL-1β before and after labor. DESIGN Myometrial tissues obtained from pregnant women at term before (n = 12) or during labor (n = 10) and pathological cases of choriamnionitis-associated term labor (n = 5) were used to isolate primary myocytes and investigate in vitro, CRH effects on basal and IL-1β regulated p65 activation and PGHS2 expression. RESULTS In nonlaboring myometrial cells, CRH was unable to induce NF-κB nuclear translocation; however, it altered the temporal dynamics of IL-1β-driven NF-κB nuclear entry by initially delaying entry and subsequently prolonging retention. These CRH-R1-driven effects were associated with a modest inhibitory action in the early phase (within 2 hours) of IL-1β stimulated PGHS2 mRNA expression, whereas prolonged stimulation for 6-18 hours augmented the IL-1β effects. The early-phase effect required intact protein kinase A activity and was diminished after the onset of labor. The presence of chorioamnionitis led to exaggerated PGHS2 mRNA responses to IL-1β but diminished effects of CRH. CONCLUSIONS CRH is involved in the inflammatory regulation of PGHS2 expression before and during labor; these actions might be important in priming and preparing the myometrium for labor and cellular adaptive responses to inflammatory mediators.
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Affiliation(s)
- Danijela Markovic
- Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom
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17
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Voltolini C, Torricelli M, Conti N, Vellucci FL, Severi FM, Petraglia F. Understanding Spontaneous Preterm Birth. Reprod Sci 2013; 20:1274-92. [DOI: 10.1177/1933719113477496] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Chiara Voltolini
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Michela Torricelli
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Nathalie Conti
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Francesca L. Vellucci
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Filiberto M. Severi
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Felice Petraglia
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
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Smith R, Paul J, Maiti K, Tolosa J, Madsen G. Recent advances in understanding the endocrinology of human birth. Trends Endocrinol Metab 2012; 23:516-23. [PMID: 22682480 DOI: 10.1016/j.tem.2012.05.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 04/23/2012] [Accepted: 05/01/2012] [Indexed: 02/06/2023]
Abstract
The timing of human birth has a crucial impact upon the survival of the fetus. New knowledge on the regulation of human birth includes the role of endogenous retroviruses in the formation of the syncytiotrophoblast cells and consequently the secretion of corticotrophin releasing hormone, a hormone linked to gestational length determination. miRNAs have been identified that mediate progesterone withdrawal at labor by suppressing progesterone-induced transcription factors. Progress has also been made in understanding how the contractile machinery of the uterine myocytes is activated at labor and the role of small heat-shock proteins in this process. From this work, new therapeutic targets have been identified that may be used to regulate the onset of labor and improve neonatal mortality.
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Affiliation(s)
- Roger Smith
- Mothers and Babies Research Centre, Faculty of Health, University of Newcastle, Callaghan, NSW 2308, Australia.
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19
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Karolczak-Bayatti M, Sweeney M, Cheng J, Edey L, Robson SC, Ulrich SM, Treumann A, Taggart MJ, Europe-Finner GN. Acetylation of heat shock protein 20 (Hsp20) regulates human myometrial activity. J Biol Chem 2011; 286:34346-55. [PMID: 21803775 DOI: 10.1074/jbc.m111.278549] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphorylation of heat shock protein 20 (Hsp20) by protein kinase A (PKA) is now recognized as an important regulatory mechanism modulating contractile activity in the human myometrium. Thus agonists that stimulate cyclic AMP production may cause relaxation with resultant beneficial effects on pathologies that affect this tissue such as the onset of premature contractions prior to term. Here we describe for the first time that acetylation of Hsp20 is also a potent post-translational modification that can affect human myometrial activity. We show that histone deacetylase 8 (HDAC8) is a non-nuclear lysine deacetylase (KDAC) that can interact with Hsp20 to affect its acetylation. Importantly, use of a selective linkerless hydroxamic acid HDAC8 inhibitor increases Hsp20 acetylation with no elevation of nuclear-resident histone acetylation nor marked global gene expression changes. These effects are associated with significant inhibition of spontaneous and oxytocin-augmented contractions of ex vivo human myometrial tissue strips. A potential molecular mechanism by which Hsp20 acetylation can affect myometrial activity by liberating cofilin is described and further high-lights the use of specific effectors of KDACs as therapeutic agents in regulating contractility in this smooth muscle.
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Affiliation(s)
- Magdalena Karolczak-Bayatti
- Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom.
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20
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Karolczak-Bayatti M, Loughney AD, Robson SC, Europe-Finner GN. Epigenetic modulation of the protein kinase A RIIα (PRKAR2A) gene by histone deacetylases 1 and 2 in human smooth muscle cells. J Cell Mol Med 2011; 15:94-108. [PMID: 19818097 PMCID: PMC3822497 DOI: 10.1111/j.1582-4934.2009.00927.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Recently we reported that the expression of the protein kinase A (PKA) regulatory subunit RIIα is dynamically regulated in human smooth muscle cells of the uterus. We showed that expression levels of mRNA/protein were substantially increased during pregnancy and decreased upon labour, changes that were mirrored by particulate type II PKA activity. This implied an important role for RIIα in maintaining uterine quiescence during pregnancy. Consequently the purpose of the present study was to identify potential mechanisms by which expression of the RIIα gene was regulated in this tissue. We indicate here that the three SpI-III (GC) binding domains within the proximal promoter region of the human RIIα gene may play important roles in modulating expression of the gene in human myometrial cells. We show that all three GC binding domains are involved in binding Sp1, Sp3, histone deacetylase (HDACs) 1/2 and RbAp48 transcriptional complexes. The functional significance of these binding domains was further analysed employing in vitro luciferase reporter assays with full-length/truncated RIIα promoter constructs. Importantly we show that treatment of primary human myometrial cell cultures with the general class I/II HDAC inhibitor trichostatin A results in an increase in mRNA/protein levels. Moreover the increase in mRNA levels appeared to be preceded by an increase in aH3, PolIIa, Sp3 and HDAC 2 binding to the three SpI-III (GC) binding sites within the RIIα promoter. These results enable us to provide a model whereby RIIα expression is epigenetically regulated in human myometrial smooth muscle cells by histone deacetylase(s) activity within the GC-rich proximal promoter region of the gene.
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Affiliation(s)
- Magdalena Karolczak-Bayatti
- Institute of Cellular Medicine, Newcastle University, Faculty of Medical Sciences, Framlington Place, Newcastle upon Tyne, UK.
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21
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Ku CY, Murtazina DA, Kim YS, Garfield RE, Sanborn BM. Changes in rat myometrial plasma membrane protein kinase A are confined to parturition. Reprod Sci 2010; 17:696-704. [PMID: 20457802 DOI: 10.1177/1933719110368869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We have previously shown that pregnant rat myometrial plasma membrane-associated cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) decreases prior to delivery, coincident with a decline in the inhibitory effect of cAMP on contractant-stimulated parameters. We now find that rat myometrial membrane-associated PKA concentrations in early to mid-pregnancy are equivalent to those in cycling rats. Following the decline associated with parturition, membrane PKA recovers within 1 to 2 days postpartum. Treatment with the antiprogestin onapristone caused a decrease in myometrial membrane PKA catalytic and regulatory subunits compared to untreated controls by 12 hours. This coincided temporally with recently reported increases in electrical and contractile activity. In unilaterally pregnant rats, the decline in plasma membrane PKA was observed in both nonpregnant and pregnant horns but was more rapid in the pregnant horns. These data indicate that the myometrial plasma membrane PKA pattern before and during most of pregnancy is not consistent with progesterone exerting a primary influence on PKA membrane localization. Rather, the fall in membrane PKA associated with parturition may contribute to or be influenced by the increased contractile and electrical activity of labor that is a consequence of the loss of progesterone influence and is not absolutely dependent on the presence of fetuses.
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Affiliation(s)
- Chun-Ying Ku
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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22
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Taggart MJ, Europe-Finner GN, Mitchell BF. Possible dual roles for prostacyclin in human pregnancy and labor. J Clin Invest 2008; 118:3829-32. [PMID: 19033650 DOI: 10.1172/jci37785] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
During pregnancy, the muscular layer of the uterine wall known as the myometrium, which is composed mainly of smooth muscle cells, is maintained in a state of relative quiescence. A switch from myometrial quiescence to myometrial activation is required to establish uterine contractions during labor. Researchers have long been perplexed by the fact that the major prostaglandin produced by the uterus just prior to labor, prostacyclin, is a smooth muscle relaxant. In this issue of the JCI, Fetalvero et al. provide data that they propose explains this paradox, at least in part (see the related article beginning on page 3966). The authors examined uterine tissue from pregnant women near term and found that prostacyclin stimulation, which raises cAMP levels that were previously thought to affect only myometrial quiescence, can promote myometrial activation over time by increasing the expression of a select group of proteins thought to be indicative of a uterine contractile state.
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Affiliation(s)
- Michael J Taggart
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.
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23
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Moynihan AT, Hehir MP, Sharkey AM, Robson SC, Europe-Finner GN, Morrison JJ. Histone deacetylase inhibitors and a functional potent inhibitory effect on human uterine contractility. Am J Obstet Gynecol 2008; 199:167.e1-7. [PMID: 18455134 DOI: 10.1016/j.ajog.2008.01.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 10/18/2007] [Accepted: 01/08/2008] [Indexed: 11/17/2022]
Abstract
OBJECTIVE This study was undertaken to investigate the effects of 3 histone deacetylase inhibitors on human uterine contractility. STUDY DESIGN Biopsy specimens of human myometrium were obtained at elective cesarean section (n = 18). Dissected myometrial strips suspended under isometric conditions, undergoing spontaneous, and oxytocin-induced contractions, were subjected to cumulative additions of 3 histone deacetylase inhibitors: trichostatin A, suberic bishydroxamate (1 nmol/L-10 micromol/L) and valproic acid (100 nmol/L--1 mmol/L). Control experiments were run simultaneously. Integrals of contractile activity were measured by using the PowerLab hardware unit and Chart v3.6 software. Data were analyzed by using 1-way analysis of variance, followed by post hoc analysis. RESULTS All 3 histone deacetylase inhibitor compounds exerted a potent and cumulative inhibitory effect on spontaneous (n = 18) and oxytocin-induced (n =18) contractility. The mean maximal inhibition values for the 3 compounds were as follows: trichostatin A, 46-54% (P < .05); valproic acid, 35-36% (P < .05); and suberic bishydroxamate, 53-65% (P < .05). CONCLUSION The histone deacetylase inhibitors trichostatin A, valproic acid, and suberic bishydroxamate exerted a potent inhibitory effect on human uterine contractions. This raises the possibility that this new class of compounds may have tocolytic potential, in addition to their current clinical indications. We speculate that this inhibitory effect may be linked, at least in part, to the ability of histone deacetylase inhibitors to induce the expression of genes involved in maintaining myometrial quiescence via epigenetic mechanisms but may also potentially involve nonepigenetic pathways.
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Affiliation(s)
- Audrey T Moynihan
- Department of Obstetrics and Gynaecology, Clinical Science Institute, University College Hospital Galway, Galway, Ireland
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24
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Everts RE, Chavatte-Palmer P, Razzak A, Hue I, Green CA, Oliveira R, Vignon X, Rodriguez-Zas SL, Tian XC, Yang X, Renard JP, Lewin HA. Aberrant gene expression patterns in placentomes are associated with phenotypically normal and abnormal cattle cloned by somatic cell nuclear transfer. Physiol Genomics 2008; 33:65-77. [DOI: 10.1152/physiolgenomics.00223.2007] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transcription profiling of placentomes derived from somatic cell nuclear transfer (SCNT, n = 20), in vitro fertilization (IVF, n = 9), and artificial insemination (AI, n = 9) at or near term development was performed to better understand why SCNT and IVF often result in placental defects, hydrops, and large offspring syndrome (LOS). Multivariate analysis of variance was used to distinguish the effects of SCNT, IVF, and AI on gene expression, taking into account the effects of parturition (term or preterm), sex of fetus, breed of dam, breed of fetus, and pathological finding in the offspring (hydrops, normal, or other abnormalities). Differential expression of 20 physiologically important genes was confirmed with quantitative PCR. The largest effect on placentome gene expression was attributable to whether placentas were collected at term or preterm (i.e., whether the collection was because of disease or to obtain stage-matched controls) followed by placentome source (AI, IVF, or SCNT). Gene expression in SCNT placentomes was dramatically different from AI ( n = 336 genes; 276 >2-fold) and from IVF ( n = 733 genes; 162 >2-fold) placentomes. Functional analysis of differentially expressed genes (DEG) showed that IVF has significant effects on genes associated with cellular metabolism. In contrast, DEG associated with SCNT are involved in multiple pathways, including cell cycle, cell death, and gene expression. Many DEG were shared between the gene lists for IVF and SCNT comparisons, suggesting that common pathways are affected by the embryo culture methods used for IVF and SCNT. However, the many unique gene functions and pathways affected by SCNT suggest that cloned fetuses may be starved and accumulating toxic wastes due to placental insufficiency caused by reprogramming errors. Many of these genes are candidates for hydrops and LOS.
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Affiliation(s)
- Robin E. Everts
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Pascale Chavatte-Palmer
- UMR Biologie du Développement et Reproduction, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Anthony Razzak
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Isabelle Hue
- UMR Biologie du Développement et Reproduction, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Cheryl A. Green
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Rosane Oliveira
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Xavier Vignon
- UMR Biologie du Développement et Reproduction, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | | | - X. Cindy Tian
- Center for Regenerative Biology/Department of Animal Sciences, University of Connecticut, Storrs, Connecticut
| | - Xiangzhong Yang
- Center for Regenerative Biology/Department of Animal Sciences, University of Connecticut, Storrs, Connecticut
| | - Jean-Paul Renard
- UMR Biologie du Développement et Reproduction, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Harris A. Lewin
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois
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Abstract
One of the most important stages of pregnancy is the activation of uterine contractions that result in the expulsion of the fetus. The timely onset of labour is clearly important for a healthy start to life but incomplete understanding of the precise mechanisms regulating labour onset have prohibited the development of effective and safe treatments for preterm labour. This review explores the activation of the myometrium at labour onset, focussing on mechanisms of uterine contractility, including those proteins that play an important role in smooth muscle contractility. The review primarily focuses on human work but in the absence of human data describes animal studies. A broad overview of myometrial contraction mechanisms is provided before discussing more detailed aspects and identifying areas where uncertainty remains. Also discussed is the recent application of ‘omics’ based approaches to parturition research, which has facilitated an increase in the understanding of myometrial activation.
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26
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Taggart MJ, Morgan KG. Regulation of the uterine contractile apparatus and cytoskeleton. Semin Cell Dev Biol 2007; 18:296-304. [PMID: 17582796 PMCID: PMC2001260 DOI: 10.1016/j.semcdb.2007.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Accepted: 05/03/2007] [Indexed: 01/16/2023]
Abstract
Parturition at term, the end stage of a successful pregnancy, occurs as a result of powerful, co-ordinated and periodic contractions of uterine smooth muscle (myometrium). To occur in a propitious manner, a high degree of control over the activation of a myometrial cell is required. We review the molecular mechanisms and structural composition of myometrial cells that may contribute to their increased contractile capacity at term. We focus attention on pathways that lead to the activation of filamentous networks traditionally labeled 'contractile' or 'cytoskeletal' yet draw attention to the fact that functional discrimination between these systems is not absolute.
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Affiliation(s)
- Michael J Taggart
- Maternal & Fetal Health Research Centre & Cardiovascular Research Group, University of Manchester, St Mary’s Hospital, Hathersage Road, Manchester, M130JH, UK, Tel: +44 161 276 5469, Fax: +44 161 276 6134, E mail:
| | - Kathleen G Morgan
- Health Sciences Department, Sargent College, Boston University, 635 Commonwealth Avenue, Boston MA 02215, USA, Tel: 617-353-7464, Fax: 617-353-7567, E-mail:
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27
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López Bernal A. The regulation of uterine relaxation. Semin Cell Dev Biol 2007; 18:340-7. [PMID: 17582797 DOI: 10.1016/j.semcdb.2007.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Accepted: 05/03/2007] [Indexed: 10/23/2022]
Abstract
The regulation of uterine relaxation is poorly understood but research in myometrial tissue and other types of smooth muscle has defined a number of receptors, ion channels and regulatory proteins that are likely to be involved. Some of these proteins are substrates for protein kinases, especially cyclic nucleotide dependent kinases. More research is necessary to identify the key molecules involved in the maintenance of uterine quiescence in pregnancy. The use of tocolytics in preterm labour remains controversial; there is a need to identify better pharmacological targets to provoke safe and selective uterine relaxation and improve neonatal outcome.
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Affiliation(s)
- A López Bernal
- University of Bristol, Department of Clinical Science at South Bristol (Obstetrics & Gynaecology), Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Whitson Street, Bristol BS1 3NY, UK.
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28
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Affiliation(s)
- Roger Smith
- Mothers and Babies Research Centre, Hunter Medical Research Institute, John Hunter Hospital, Newcastle, NSW, Australia.
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Tyson-Capper AJ, Cork DMW, Wesley E, Shiells EA, Loughney AD. Characterization of cellular retinoid-binding proteins in human myometrium during pregnancy. ACTA ACUST UNITED AC 2006; 12:695-701. [PMID: 16959971 DOI: 10.1093/molehr/gal070] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Many complementary or competing signalling pathways bear an influence on the myometrium at any one time, and because the retinoic acid signalling pathway influences differentiation of a wide array of human tissues, this may be one of the determinants of myometrial differentiation during pregnancy. We have explored the novel hypothesis that the retinoids may act as important regulators in controlling the differentiated state of the human myometrium during pregnancy by characterizing the expression profiles for cellular retinoid-binding proteins CRBPI, CRABPI and CRABPII in non-pregnant, pregnant (non-labouring) and labouring human myometrium taken from the functionally distinct upper and lower uterine segments. In addition, we have investigated the effect of all-trans retinoic acid (ATRA) on the expression of several retinoic acid response genes including cyclooxygenase-2 (COX-2) and connexin-43 (Cx-43). Different spatial and temporal patterns of expression were observed for CRBPI, CRABPI and CRABPII within the upper and lower uterine segments through the three trimesters of pregnancy and in labour. Furthermore, the expression of COX-2, Cx-43, CRABPI, the transcription factor c-Jun and the retinoic acid receptor RARbeta altered in response to different concentrations of ATRA, suggesting that the differential expression of cellular retinoid-binding proteins may lead to different levels of retinoic acid being delivered to its nuclear targets, leading to the differential expression of specific target genes within the myometrium during pregnancy.
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Affiliation(s)
- Alison J Tyson-Capper
- School of Surgical and Reproductive Sciences, The Medical School, University of Newcastle upon Tyne, UK.
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30
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Sanborn BM, Ku CY, Shlykov S, Babich L. Molecular signaling through G-protein-coupled receptors and the control of intracellular calcium in myometrium. ACTA ACUST UNITED AC 2006; 12:479-87. [PMID: 16202924 DOI: 10.1016/j.jsgi.2005.07.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Indexed: 11/30/2022]
Abstract
Cellular mechanisms regulating myometrial intracellular free calcium (Ca2+(i)) are addressed in this review, with emphasis on G-protein-coupled receptor pathways. An increase in myometrial Ca2+(i) results in phosphorylation of myosin light chain, an increase in myosin adenosine monophosphatase (ATPase) activity and contraction. Dephosphorylation of myosin light chain and a decline in Ca2+(i) are associated with relaxation. Increases in Ca2+(i) are controlled by multiple signaling pathways, including receptor-mediated activation of phospholipase Cbeta (PLCbeta), leading to release of Ca2+ from intracellular stores. Ca2+ also enters myometrial cells through plasma membrane Ca2+ channels. Conversely, adenosine triphosphate (ATP)-dependent Ca2+ pumps lower Ca2+(i) concentrations and potassium channels promote hyperpolarization that can decrease Ca2+ entry. Receptor-coupled pathways that promote uterine relaxation primarily involve activation of cyclic adenosine monophosphate (cAMP)- or cyclic guanosine monophosphate (cGMP)-stimulated protein kinases that phosphorylate proteins regulating Ca2+ homeostasis. cAMP has inhibitory effects on myometrial contractile activity, agonist-stimulated phosphatidylinositide turnover and increases in Ca2+(i). Some of these effects require association of protein kinase A (PKA) with a plasma membrane-associated A-kinase-anchoring-protein (AKAP). Near term in the rat, there is a decline in the plasma membrane localization of PKA associated with this anchoring protein. This correlates with changes in the regulation of signaling pathways controlling Ca2+(i). L-type voltage-operated Ca2+ entry is an important regulator of myometrial contraction. In addition, putative signal-regulated or capacitative Ca2+ channel proteins, TrpCs, are expressed in myometrium, and signal-regulated Ca2+ entry is observed in human myometrial cells. This Ca2+ entry mechanism may play a significant role in the control of myometrial Ca2+(i) dynamics and myometrial contraction. The regulation of myometrial Ca2+(i) is complex. Understanding the mechanisms involved may lead to design of tocolytics that target multiple pathways and achieve improved suppression of premature labor.
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Affiliation(s)
- Barbara M Sanborn
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
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Abstract
Relaxin exhibits pleiotropic effects on reproductive and nonreproductive tissues; the signaling mechanisms underlying these functions are still not well understood. Activation of protein kinase A and several other signal-regulated protein kinases results in the phosphorylation of phospholipase C (PLC)-beta3 and inhibit Galpha(q)-stimulated PLC activity. Therefore, PLCbeta3 may be targeted by both contractant and relaxant signaling pathways in myometrium and play a critical role in the balance between them. PHM1 cells express mRNA for relaxin receptor LGR7, and relaxin inhibits oxytocin-stimulated PLC activity in these cells. Thus, this model system may be useful in delineating signaling pathways used by relaxin. Here, we present evidence that relaxin stimulates phosphorylation of PLCbeta3 in PHM1 cells.
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Affiliation(s)
- Miao Zhong
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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Otun HA, MacDougall MWJ, Bailey J, Europe-Finner GN, Robson SC. Spatial and temporal expression of the myometrial mitogen-activated protein kinases p38 and ERK1/2 in the human uterus during pregnancy and labor. ACTA ACUST UNITED AC 2005; 12:185-90. [PMID: 15784503 DOI: 10.1016/j.jsgi.2004.11.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
OBJECTIVE We have recently identified a novel putative spliced variant of the activating transcription factor 2 (ATF2) in the human myometrium during pregnancy and labor. This protein, termed ATF2-sm like full-length ATF2, acts as a potent transactivator of cyclic adenosine monophosphate response element (CRE)-containing promoter reporter genes. Similarly, employing microarray gene profiling in myometrial cells, we have shown ATF2-sm to affect the expression of several specific myometrial genes associated with regulating uterine activity during pregnancy and labor. At some point after conception this transcription factor becomes spatially expressed within the body of the uterus, with significantly higher levels detected in the upper (corpus) compared to the lower uterine segment. Because ATF2 species are the primary substrate for phosphorylation by the mitogen-activated protein kinases (MAPKs) p38 and ERK1/2, the purpose of the current investigation was to define the expression levels of these kinases in upper and lower segment myometrium during pregnancy and labor to see if they also correlated with expression of ATF2-sm. METHODS Paired myometrial samples were collected from the upper (corpus) and lower uterine segments from term nonlaboring and spontaneously laboring women undergoing elective and emergency cesarean deliveries, respectively. Non-pregnant myometrial samples were collected from premenopausal women having hysterectomies for benign gynecologic disorders. The MAPKs p38 and ERK1/2 present in individual myometrial homogenates were resolved using sodium dodecyl sulfate polacrylamide gel electropheresis (SDS-PAGE) with subsequent Western blotting with specific antibodies and scanning densitometry. Expression of the individual MAPKs in myometrial tissues was confirmed in situ using immunohistochemistry. RESULTS In non-pregnant tissues, p38 and ERK1/2 expression was uniform throughout the uterus. In term pregnant nonlaboring and spontaneously laboring samples expression of p38 and ERK1 was significantly elevated in the upper uterine segment compared to the lower segment, respectively. In contrast, there was no difference in ERK2 expression. CONCLUSION The data from this study indicate that both p38 and ERK1 are spatially regulated in different uterine regions during pregnancy/labor and suggest that they may be involved in regulating the activity of ATF2 isoforms and their subsequent effects on myometrial function.
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Affiliation(s)
- Harry A Otun
- School of Surgical and Reproductive Sciences, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne, United Kingdom.
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Long AA, Chapman NR, Innes B, Europe-Finner GN, Robson SC. Expression and interaction of the transcriptional coregulators, CBP/p300, in the human myometrium during pregnancy and labor. ACTA ACUST UNITED AC 2005; 12:92-7. [PMID: 15695103 DOI: 10.1016/j.jsgi.2004.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE In humans, the factors that govern the switch from myometrial quiescence to coordinated contractions at the initiation of labor are not well defined. Recent studies have highlighted a role for the coactivator, CREB binding protein (CBP), in the human myometrium during pregnancy and labor through its ability to acetylate histones. In the present study, the expression of CBP and its related coactivator, p300, were examined. METHODS Levels and interactions of CBP and its paralogue p300 were determined by Western blotting, immunohistochemistry, and coimmunoprecipitation experiments using myometrial biopsy samples from nonpregnant (NP), pregnant nonlaboring (P), and spontaneously laboring (SL) women. RESULTS Levels of CBP were seen to increase in term P myometrial samples but were then greatly reduced in SL myometrium. In contrast, levels of p300 remained uniform between NP, P, and SL tissues. These observations were confirmed by immunhistochemical analyses. Immunoprecipitation experiments highlighted that CBP was able to interact with CREB, CREM, ATF-2, and p300 in P lower segment myometrium. CONCLUSION Recent evidence suggests that competition for CBP plays an important role in regulating gene expression during cell growth. Consequently our data suggest that the increase in myometrial CBP levels during pregnancy may occur to meet this increase in CBP demand. Moreover, from coimmunoprecipitation experiments, this increase in CBP expression would be expected to facilitate the transactivation potential of the cyclic adenosine monophosphate (cAMP)-dependent transcription factors CREB, CREM, and ATF-2.
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Affiliation(s)
- Audrey A Long
- School of Surgical and Reproductive Sciences (Obstetrics and Gynaecology), University of Newcastle-upon-Tyne, Newcastle-upon-Tyne, United Kingdom
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Riley M, Baker PN, Tribe RM, Taggart MJ. Expression of scaffolding, signalling and contractile-filament proteins in human myometria: effects of pregnancy and labour. J Cell Mol Med 2005; 9:122-34. [PMID: 15784170 PMCID: PMC1351332 DOI: 10.1111/j.1582-4934.2005.tb00342.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Successful parturition requires the co-ordination of numerous myometrial signalling events to allow for timely and efficient uterine contractions. Late pregnancy and labour onset in humans may be associated with changes in the expression of myometrial proteins implicated in such uterine contractile signal integration. Accordingly, in myometria from non-pregnant women and pregnant women, not in labour or in labour, we examined the content of putative plasmalemmal scaffolding proteins (caveolin-1 and -2) and compared these to the proportions of signal transducing rho-associated kinases (ROKalpha and beta) and contractile filament-associated proteins alpha-actin, myosin regulatory light chain (MLC(20)) and h-caldesmon. There was no effect of pregnancy or labour on the proportion of caveolin, ROK betaor alpha-actin. However, pregnancy was associated with a decrease in ROKalpha and MLC(20) such that ROK alpha: alpha-actin and MLC(20): alpha-actin ratios were reduced compared to myometria of non-pregnant women. In contrast, h-caldesmon was up-regulated in pregnancy resulting in an elevated h-caldesmon: alpha-actin ratio. There were, however, no further significant changes in ROK alpha, MLC(20) or h-caldesmon expression with spontaneous or oxytocin-induced labour. These data suggest that the mechanism(s) integrating myometrial signalling events with the onset of human labour does not involve differential alterations of the cellular expressions of caveolins, ROK, alpha-actin, MLC(20) or h-caldesmon.
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Affiliation(s)
- M Riley
- Maternal and Fetal Health Research Centre, St Mary's Hospital, Manchester, Great Britain
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Chapman NR, Europe-Finner GN, Robson SC. Expression and deoxyribonucleic acid-binding activity of the nuclear factor kappaB family in the human myometrium during pregnancy and labor. J Clin Endocrinol Metab 2004; 89:5683-93. [PMID: 15531529 DOI: 10.1210/jc.2004-0873] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In humans, the factors that govern the switch from myometrial quiescence to coordinated contractions at the initiation of labor are not well defined. The onset of parturition is itself associated with increases in a number of proinflammatory factors, many of which are regulated by the nuclear factor kappaB (NF-kappaB) family of transcription factors. The expression and DNA-binding activity of NF-kappaB in the myometrium during gestation and parturition were examined. Levels of c-Rel, p50, and p105 NF-kappaB species were dramatically reduced in pregnant myometrium compared with nonpregnant (NP) controls, whereas expression of the RelA subunit remained uniform. Importantly, during labor, expression of all subunits was observed to be significantly reduced in all myometrial samples studied relative to NP levels. Moreover, for RelA, c-Rel, and p50 subunits, there was a gradient of expression between laboring upper (corpus) and lower uterine segment myometrium. No RelB or p52 subunits could be detected. EMSAs identified changes in NF-kappaB subunit composition in the myometrium during pregnancy and labor, with p50 homodimers predominant in NP tissues being replaced with RelA:p50 heterodimers in pregnant and laboring samples. Significantly, RelA was observed to be phosphorylated at serine-536, implicating the involvement of the phosphatidylinositol-3-kinase/AKT pathway in NF-kappaB function in the myometrium.
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Affiliation(s)
- Neil R Chapman
- School of Surgical and Reproductive Sciences (Obstetrics and Gynaecology), Third Floor, Faculty of Medical Sciences, University of Newcastle-upon-Tyne, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom.
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