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Riaposova L, Kim SH, Hanyaloglu AC, Sykes L, MacIntyre DA, Bennett PR, Terzidou V. Prostaglandin F2α requires activation of calcium-dependent signalling to trigger inflammation in human myometrium. Front Endocrinol (Lausanne) 2023; 14:1150125. [PMID: 37547305 PMCID: PMC10400332 DOI: 10.3389/fendo.2023.1150125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 06/06/2023] [Indexed: 08/08/2023] Open
Abstract
Introduction Preterm birth is one of the major causes of neonatal morbidity and mortality across the world. Both term and preterm labour are preceded by inflammatory activation in uterine tissues. This includes increased leukocyte infiltration, and subsequent increase in chemokine and cytokine levels, activation of pro-inflammatory transcription factors as NF-κB and increased prostaglandin synthesis. Prostaglandin F2α (PGF2α) is one of the myometrial activators and stimulators. Methods Here we investigated the role of PGF2α in pro-inflammatory signalling pathways in human myometrial cells isolated from term non-labouring uterine tissue. Primary myometrial cells were treated with G protein inhibitors, calcium chelators and/or PGF2α. Nuclear extracts were analysed by TranSignal cAMP/Calcium Protein/DNA Array. Whole cell protein lysates were analysed by Western blotting. mRNA levels of target genes were analysed by RT-PCR. Results The results show that PGF2α increases inflammation in myometrial cells through increased activation of NF-κB and MAP kinases and increased expression of COX-2. PGF2α was found to activate several calcium/cAMP-dependent transcription factors, such as CREB and C/EBP-β. mRNA levels of NF-κB-regulated cytokines and chemokines were also elevated with PGF2α stimulation. We have shown that the increase in PGF2α-mediated COX-2 expression in myometrial cells requires coupling of the FP receptor to both Gαq and Gαi proteins. Additionally, PGF2α-induced calcium response was also mediated through Gαq and Gαi coupling. Discussion In summary, our findings suggest that PGF2α-induced inflammation in myometrial cells involves activation of several transcription factors - NF-κB, MAP kinases, CREB and C/EBP-β. Our results indicate that the FP receptor signals via Gαq and Gαi coupling in myometrium. This work provides insight into PGF2α pro-inflammatory signalling in term myometrium prior to the onset of labour and suggests that PGF2α signalling pathways could be a potential target for management of preterm labour.
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Affiliation(s)
- Lucia Riaposova
- Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
- The March of Dimes European Prematurity Research Centre at Imperial College London, London, United Kingdom
| | - Sung Hye Kim
- Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
- The March of Dimes European Prematurity Research Centre at Imperial College London, London, United Kingdom
| | - Aylin C. Hanyaloglu
- Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Lynne Sykes
- Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
- The March of Dimes European Prematurity Research Centre at Imperial College London, London, United Kingdom
- The Parasol Foundation Centre for Women’s Health and Cancer Research, St Mary’s Hospital, Imperial College Healthcare National Health Service (NHS) Trust, London, United Kingdom
| | - David A. MacIntyre
- Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
- The March of Dimes European Prematurity Research Centre at Imperial College London, London, United Kingdom
| | - Phillip R. Bennett
- Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
- The March of Dimes European Prematurity Research Centre at Imperial College London, London, United Kingdom
| | - Vasso Terzidou
- Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
- The March of Dimes European Prematurity Research Centre at Imperial College London, London, United Kingdom
- Department of Obstetrics & Gynaecology, Chelsea and Westminster Hospital National Health Service (NHS) Trust, London, United Kingdom
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Calcium signaling cascades differentially regulate PGF 2α-induced myometrial contractions in water buffaloes (Bubalus bubalis). Naunyn Schmiedebergs Arch Pharmacol 2021; 394:1651-1664. [PMID: 33884445 DOI: 10.1007/s00210-021-02084-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 03/30/2021] [Indexed: 10/21/2022]
Abstract
This study unravels the differential involvement of calcium signaling pathway(s) in PGF2α-induced contractions in myometrium of nonpregnant (NP) and pregnant buffaloes. Compared to the myometrium of pregnant animals, myometrium of NP buffaloes was more sensitive to PGF2α as manifested by changes in mean integral tension (MIT) and tonicity. In the presence of nifedipine, myometrial contraction to PGF2α was significantly attenuated in both NP and pregnant uteri; however, mibefradil and NNC 55-0396 produced inhibitory effects only in uterus of pregnant animals, thus suggesting the role of extracellular Ca2+ influx through nifedipine-sensitive L-type Ca2+-channels both in NP and pregnant, but T-type Ca2+ channels seem to play a role only during pregnancy. Entry of extracellular Ca2+ is triggered by enhanced functional involvement of Pyr3-sensitive TRPC3 channels and Rho-kinase pathways as evidenced by a significant rightward shift of the concentration-response curve of PGF2α in the presence of Pyr3 and Y-27632 in NP myometrium. But significant down-expressions of TRPC3 and Rho-A proteins during pregnancy apparently facilitate uterine quiescence. In the presence of Ca2+-free solution and cyclopiazonic acid (SERCA blocker), feeble contraction to PGF2α was observed in both NP and pregnant myometrium which suggests minor role of intracellular source of Ca2+ in mediating PGF2α-induced contractions in these tissues.
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Biringer RG. A Review of Prostanoid Receptors: Expression, Characterization, Regulation, and Mechanism of Action. J Cell Commun Signal 2020; 15:155-184. [PMID: 32970276 DOI: 10.1007/s12079-020-00585-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 09/15/2020] [Indexed: 12/22/2022] Open
Abstract
Prostaglandin signaling controls a wide range of biological processes from blood pressure homeostasis to inflammation and resolution thereof to the perception of pain to cell survival. Disruption of normal prostanoid signaling is implicated in numerous disease states. Prostaglandin signaling is facilitated by G-protein-coupled, prostanoid-specific receptors and the array of associated G-proteins. This review focuses on the expression, characterization, regulation, and mechanism of action of prostanoid receptors with particular emphasis on human isoforms.
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Affiliation(s)
- Roger G Biringer
- College of Osteopathic Medicine, Lake Erie College of Osteopathic Medicine, 5000 Lakewood Ranch Blvd, Bradenton, FL, 34211, USA.
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4
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Bafor EE, Rowan EG, Edrada-Ebel R. Metabolomics-Coupled Functional Pharmacology of Chlorophyll Compounds Isolated From the Leaves of Ficus Exasperata Vahl (Moraceae) Provides Novel Pathways on Myometrial Activity. Reprod Sci 2017; 25:923-937. [DOI: 10.1177/1933719117732159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Enitome E. Bafor
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, United Kingdom
- Department of Pharmacology and Toxicology, University of Benin, Benin City, Nigeria
| | - Edward G. Rowan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, United Kingdom
| | - RuAngelie Edrada-Ebel
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, United Kingdom
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5
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Sharma A, Nakade UP, Jaitley P, Sharma V, Choudhury S, Garg SK. WITHDRAWN: Differential involvement of L- and T-type Ca 2+ channels, store-operated calcium channel (TRPC) and Rho-kinase signaling pathway(s) in PGF 2α-induced contractions in myometrium of non-pregnant and pregnant buffaloes (Bubalus bubalis). Prostaglandins Other Lipid Mediat 2017:S1098-8823(17)30021-7. [PMID: 28916261 DOI: 10.1016/j.prostaglandins.2017.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 11/30/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.
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Affiliation(s)
- Abhishek Sharma
- Experimental Pharmacology Laboratory, Department of Pharmacology & Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya, Evam Go-Anusandhan Sansthan (DUVASU), Mathura 281001, India
| | - Udayraj P Nakade
- Experimental Pharmacology Laboratory, Department of Pharmacology & Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya, Evam Go-Anusandhan Sansthan (DUVASU), Mathura 281001, India
| | - Pooja Jaitley
- Experimental Pharmacology Laboratory, Department of Pharmacology & Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya, Evam Go-Anusandhan Sansthan (DUVASU), Mathura 281001, India
| | - Vipin Sharma
- Experimental Pharmacology Laboratory, Department of Pharmacology & Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya, Evam Go-Anusandhan Sansthan (DUVASU), Mathura 281001, India
| | - Soumen Choudhury
- Experimental Pharmacology Laboratory, Department of Pharmacology & Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya, Evam Go-Anusandhan Sansthan (DUVASU), Mathura 281001, India
| | - Satish Kumar Garg
- Experimental Pharmacology Laboratory, Department of Pharmacology & Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya, Evam Go-Anusandhan Sansthan (DUVASU), Mathura 281001, India.
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Flucrypyrim, a novel uterine relaxant, has antinociceptive and anti-inflammatory effects in vivo. Sci Rep 2017; 7:42040. [PMID: 28220794 PMCID: PMC5318994 DOI: 10.1038/srep42040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 01/05/2017] [Indexed: 11/09/2022] Open
Abstract
Consequences of primary dsysmenorrhea (PD) can be severe. Increased prostaglandin production leads to uterine contraction and insufficient blood flow to the endometrium causing ischemia and pain symptoms. Protein tyrosine kinase/phosphatase activities contribute to the modulation of uterine contraction. In our previous study, we found the synthetic β-methoxyacrylates compound Fluacrypyrim (FAPM), significantly increased protein tyrosine phosphatases (PTPs) activity, resulting in dephosphorylation of tyrosine kinases. In the present study, we found that FAPM near completely inhibited prostaglandin F2α (PGF2α)-, oxytocin-, acetylcholine-, and high K+-induced uterine contractions in rats in vitro, and decreased rat myometrial myosin light chain (MLC20) phosphorylation induced by PGF2α. A structure–activity relationship assay indicated that the β-methoxyacrylates structure of FAPM is crucial for the inhibition of PGF2α-induced uterine contractions. FAPM caused a concentration-dependent parallel rightward shift of the concentration–response curve induced by oxytocin, dose-dependently reduced the number of abdominal constrictions and increased the latency time in PGF2α- and acetic acid-induced writhing test in mice in vivo. Furthermore, FAPM considerably inhibited the development of Carr-induced rat paw edemas and thexylene-induced mouse ear edemas. Taken together, our results indicate that FAPM exerts antinociceptive and anti-inflammatory effects in vivo with considerable potential as a novel uterine relaxant.
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Refuerzo JS, Leonard F, Bulayeva N, Gorenstein D, Chiossi G, Ontiveros A, Longo M, Godin B. Uterus-targeted liposomes for preterm labor management: studies in pregnant mice. Sci Rep 2016; 6:34710. [PMID: 27725717 PMCID: PMC5057095 DOI: 10.1038/srep34710] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 09/19/2016] [Indexed: 12/21/2022] Open
Abstract
Preterm labor caused by uterine contractions is a major contributor to neonatal morbidity and mortality. Treatment intended to reduce uterine contractions include tocolytic agents, such as indomethacin. Unfortunately, clinically used tocolytics are frequently inefficient and cross the placenta causing fetal side effects. Here we show for the first time in obstetrics the use of a targeted nanoparticle directed to the pregnant uterus and loaded with a tocolytic for reducing its placental passage and sustaining its efficacy. Nanoliposomes encapsulating indomethacin and decorated with clinically used oxytocin receptor antagonist were designed and evaluated in-vitro, ex-vivo and in-vivo. The proposed approach resulted in targeting uterine cells in-vitro, inhibiting uterine contractions ex-vivo, while doubling uterine drug concentration, decreasing fetal levels, and maintaining the preterm birth rate in vivo in a pregnant mouse model. This promising approach opens new horizons for drug development in obstetrics that could greatly impact preterm birth, which currently has no successful treatments.
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Affiliation(s)
- Jerrie S Refuerzo
- Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Fransisca Leonard
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, Texas, USA
| | - Nataliya Bulayeva
- Department of NanoMedicine and Biomedical Engineering, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - David Gorenstein
- Department of NanoMedicine and Biomedical Engineering, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Giuseppe Chiossi
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology at University of Texas Medical Branch at Galveston, Galveston, Texas, USA
| | - Alejandra Ontiveros
- Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Monica Longo
- Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Biana Godin
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, Texas, USA
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8
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Nadeau-Vallée M, Boudreault A, Leimert K, Hou X, Obari D, Madaan A, Rouget R, Zhu T, Belarbi L, Brien MÈ, Beaudry-Richard A, Olson DM, Girard S, Chemtob S. Uterotonic Neuromedin U Receptor 2 and Its Ligands Are Upregulated by Inflammation in Mice and Humans, and Elicit Preterm Birth. Biol Reprod 2016; 95:72. [PMID: 27512149 PMCID: PMC5394981 DOI: 10.1095/biolreprod.116.140905] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/04/2016] [Indexed: 11/18/2022] Open
Abstract
Uterine labor requires the conversion of a quiescent (propregnancy) uterus into an activated (prolabor) uterus, with increased sensitivity to endogenous uterotonic molecules. This activation is induced by stressors, particularly inflammation in term and preterm labor. Neuromedin U (NmU) is a neuropeptide known for its uterocontractile effects in rodents. The objective of the study was to assess the expression and function of neuromedin U receptor 2 (NmU-R2) and its ligands NmU and the more potent neuromedin S (NmS) in gestational tissues, and the possible implication of inflammatory stressors in triggering this system. Our data show that NmU and NmS are uterotonic ex vivo in murine tissue, and they dose-dependently trigger labor by acting specifically via NmU-R2. Expression of NmU-R2, NmU, and NmS is detected in murine and human gestational tissues by immunoblot, and the expression of NmS in placenta and of NmU-R2 in uterus increases considerably with gestation age and labor, which is associated with amplified NmU-induced uterocontractile response in mice. NmU- and NmS-induced contraction is associated with increased NmU-R2-coupled Ca++ transients, and Akt and Erk activation in murine primary myometrial smooth muscle cells (mSMCs), which are potentiated with gestational age. NmU-R2 is upregulated in vitro in mSMCs and in vivo in uterus in response to proinflammatory interleukin 1beta (IL1beta), which is associated with increased NmU-induced uterocontractile response and Ca++ transients in murine and human mSMCs; additionally, placental NmS is markedly upregulated in vivo in response to IL1beta. In human placenta at term, immunohistological analysis revealed NmS expression primarily in cytotrophoblasts; furthermore, stimulation with lipopolysaccharide (LPS; Gram-negative endotoxin) markedly upregulates NmS expression in primary human cytotrophoblasts isolated from term placentas. Correspondingly, decidua of women with clinical signs of infection who delivered preterm display significantly higher expression of NmS compared with those without infection. Importantly, in vivo knockdown of NmU-R2 prevents LPS-triggered preterm birth in mice and the associated neonatal mortality. Altogether, our data suggest a critical role for NmU-R2 and its ligands NmU and NmS in preterm labor triggered by infection. We hereby identify NmU-R2 as a relevant target for preterm birth.
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Affiliation(s)
- Mathieu Nadeau-Vallée
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada Department of Pharmacology, Université de Montréal, Montreal, Quebec, Canada
| | - Amarilys Boudreault
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada
| | - Kelycia Leimert
- Departments of Obstetrics and Gynecology, Pediatrics, and Physiology, University of Alberta, Edmonton, Alberta, Canada
| | - Xin Hou
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada
| | - Dima Obari
- Department of Pharmacology, Université de Montréal, Montreal, Quebec, Canada
| | - Ankush Madaan
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Raphaël Rouget
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada
| | - Tang Zhu
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada
| | - Lydia Belarbi
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada
| | - Marie-Ève Brien
- Departments of Obstetrics and Gynecology, CHU Sainte-Justine Research Center, Montreal, Quebec, Canada
| | - Alexandra Beaudry-Richard
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada
| | - David M Olson
- Departments of Obstetrics and Gynecology, Pediatrics, and Physiology, University of Alberta, Edmonton, Alberta, Canada
| | - Sylvie Girard
- Departments of Obstetrics and Gynecology, CHU Sainte-Justine Research Center, Montreal, Quebec, Canada
| | - Sylvain Chemtob
- Departments of Pediatrics, Ophthalmology, and Pharmacology, CHU Sainte-Justine Research Centre, Montreal, Quebec, Canada Department of Pharmacology, Université de Montréal, Montreal, Quebec, Canada Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada
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9
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Voltolini C, Petraglia F. Neuroendocrinology of pregnancy and parturition. HANDBOOK OF CLINICAL NEUROLOGY 2014; 124:17-36. [PMID: 25248577 DOI: 10.1016/b978-0-444-59602-4.00002-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
During pregnancy, the maternal brain drives a series of adaptive mechanisms that are fundamental for allowing fetal growth and development, protecting both mother and fetus from adverse programming and timing of parturition. This neuroendocrine concept is even more complex as fetal brain and placenta also participate as regulators of maternal-placental-fetal physiology. The placenta is now seen as a neuroendocrine organ, acting as a source of several neuroactive factors that may exert their biologic effects either locally or by entering maternal and fetal circulation, thus acting in an autocrine, paracrine, and endocrine manner. A variety of hypothalamic neurohormones (GnRH, GHRH, somatostatin, CRH, oxytocin) are expressed in the placenta. When stress occurs during pregnancy, the maternal, fetal, and placental hypothalamic-pituitary-adrenal (HPA) axes are activated to stimulate a series of responses contributing to maintain physiologic conditions while at the same time avoiding the adverse effects of stress on the mother and offspring. However, when stress is excessive, a number of obstetric complications may occur, such as preterm birth, pre-eclampsia and intrauterine growth restriction, related to an impairment of the placental adaptive response.
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Affiliation(s)
- Chiara Voltolini
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Felice Petraglia
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
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Abstract
The complex mechanisms controlling human parturition involves mother, fetus, and placenta, and stress is a key element activating a series of physiological adaptive responses. Preterm birth is a clinical syndrome that shares several characteristics with term birth. A major role for the neuroendocrine mechanisms has been proposed, and placenta/membranes are sources for neurohormones and peptides. Oxytocin (OT) is the neurohormone whose major target is uterine contractility and placenta represents a novel source that contributes to the mechanisms of parturition. The CRH/urocortin (Ucn) family is another important neuroendocrine pathway involved in term and preterm birth. The CRH/Ucn family consists of four ligands: CRH, Ucn, Ucn2, and Ucn3. These peptides have a pleyotropic function and are expressed by human placenta and fetal membranes. Uterine contractility, blood vessel tone, and immune function are influenced by CRH/Ucns during pregnancy and undergo major changes at parturition. Among the others, neurohormones, relaxin, parathyroid hormone-related protein, opioids, neurosteroids, and monoamines are expressed and secreted from placental tissues at parturition. Preterm birth is the consequence of a premature and sustained activation of endocrine and immune responses. A preterm birth evidence for a premature activation of OT secretion as well as increased maternal plasma CRH levels suggests a pathogenic role of these neurohormones. A decrease of maternal serum CRH-binding protein is a concurrent event. At midgestation, placental hypersecretion of CRH or Ucn has been proposed as a predictive marker of subsequent preterm delivery. While placenta represents the major source for CRH, fetus abundantly secretes Ucn and adrenal dehydroepiandrosterone in women with preterm birth. The relevant role of neuroendocrine mechanisms in preterm birth is sustained by basic and clinic implications.
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Affiliation(s)
- Felice Petraglia
- University of Siena, Policlinico, Division of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics, and Reproductive Medicine, Viale Bracci, 53100 Siena, Italy.
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11
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Goupil E, Tassy D, Bourguet C, Quiniou C, Wisehart V, Pétrin D, Le Gouill C, Devost D, Zingg HH, Bouvier M, Saragovi HU, Chemtob S, Lubell WD, Claing A, Hébert TE, Laporte SA. A novel biased allosteric compound inhibitor of parturition selectively impedes the prostaglandin F2alpha-mediated Rho/ROCK signaling pathway. J Biol Chem 2010; 285:25624-36. [PMID: 20551320 DOI: 10.1074/jbc.m110.115196] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The prostaglandin F2alpha (PGF2alpha) receptor (FP) is a key regulator of parturition and a target for pharmacological management of preterm labor. However, an incomplete understanding of signaling pathways regulating myometrial contraction hinders the development of improved therapeutics. Here we used a peptidomimetic inhibitor of parturition in mice, PDC113.824, whose structure was based on the NH(2)-terminal region of the second extracellular loop of FP receptor, to gain mechanistic insight underlying FP receptor-mediated cell responses in the context of parturition. We show that PDC113.824 not only delayed normal parturition in mice but also that it inhibited both PGF2alpha- and lipopolysaccharide-induced preterm labor. PDC113.824 inhibited PGF2alpha-mediated, G(alpha)(12)-dependent activation of the Rho/ROCK signaling pathways, actin remodeling, and contraction of human myometrial cells likely by acting as a non-competitive, allosteric modulator of PGF2alpha binding. In contrast to its negative allosteric modulating effects on Rho/ROCK signaling, PDC113.824 acted as a positive allosteric modulator on PGF2alpha-mediated protein kinase C and ERK1/2 signaling. This bias in receptor-dependent signaling was explained by an increase in FP receptor coupling to G(alpha)(q), at the expense of coupling to G(alpha)(12). Our findings regarding the allosteric and biased nature of PDC113.824 offer new mechanistic insights into FP receptor signaling relevant to parturition and suggest novel therapeutic opportunities for the development of new tocolytic drugs.
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Affiliation(s)
- Eugénie Goupil
- Department of Medicine, McGill University Health Center Research Institute, Montréal H3A 1A1, Canada
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12
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Youssef RE, Ledingham MA, Bollapragada SS, O'Gorman N, Jordan F, Young A, Norman JE. The Role of Toll-Like Receptors (TLR-2 and -4) and Triggering Receptor Expressed on Myeloid Cells 1 (TREM-1) in Human Term and Preterm Labor. Reprod Sci 2009; 16:843-56. [PMID: 19564644 DOI: 10.1177/1933719109336621] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
| | | | - Shrikant S. Bollapragada
- Reproductive & Maternal Medicine, University of Glasgow, Third Floor, Queen Elizabeth Building, Glasgow Royal Infirmary, United Kingdom
| | - Neil O'Gorman
- Reproductive & Maternal Medicine, University of Glasgow, Third Floor, Queen Elizabeth Building, Glasgow Royal Infirmary, United Kingdom
| | - Fiona Jordan
- Reproductive & Maternal Medicine, University of Glasgow, Third Floor, Queen Elizabeth Building, Glasgow Royal Infirmary, United Kingdom
| | - Anne Young
- Reproductive & Maternal Medicine, University of Glasgow, Third Floor, Queen Elizabeth Building, Glasgow Royal Infirmary, United Kingdom
| | - Jane E. Norman
- University of Edinburgh Centre for Reproductive Biology, The Queen's Medical Research Institute, Edinburgh, United Kingdom
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Garcia-Verdugo I, Tanfin Z, Dallot E, Leroy MJ, Breuiller-Fouché M. Surfactant protein A signaling pathways in human uterine smooth muscle cells. Biol Reprod 2008; 79:348-55. [PMID: 18463356 DOI: 10.1095/biolreprod.108.068338] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The present study investigated the ability of surfactant associated protein A1 (SFTPA1), a major component of lung surfactant, to bind and serve as a signal in human cultured myometrial cells. By using ligand blot analysis with 125I-SFTPA1, we consistently identified two myometrial SFTPA1 interacting proteins (55 and 200 kDa). We found that the SFTPA1 immunoreactive protein was present in myometrial cells. We also showed by indirect immunofluorescence the nuclear translocation of RELA (also known as NFkappaB p65 subunit) after activation of myometrial cells by SFTPA1. Neutralization of TLR4 did not reverse this effect. Moreover, SFTPA1 rapidly activated mitogen-activated protein kinase 1/3 (MAPK1/3) and protein kinase C zeta (PRKCZ). The prolonged treatment of myometrial cells with SFTPA1 upregulated PTGS2 (COX2) protein levels. We next evaluated whether SFTPA1 affected the actin dynamic. Stimulation of myometrial cells with SFTPA1 markedly enhanced the intensity of the filamentous-actin pool stained with fluorescein isothiocyanate-phalloidin. Inhibition of PRKC or Rho-associated, coiled-coil containing protein kinase 1 (ROCK) reduced the SFTPA1-mediated stress fiber formation. Our data support the hypothesis that human myometrial cells express functional SFTPA1 binding sites and respond to SFTPA1 to initiate activation of signaling events related to human parturition.
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Affiliation(s)
- Ignacio Garcia-Verdugo
- Equipe Signalisation et Régulations Cellulaires, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, CNRS, UMR-8619, Université Paris-Sud, 91400 Orsay, France
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Sanborn BM. Hormonal signaling and signal pathway crosstalk in the control of myometrial calcium dynamics. Semin Cell Dev Biol 2007; 18:305-14. [PMID: 17627855 PMCID: PMC2000447 DOI: 10.1016/j.semcdb.2007.05.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Accepted: 05/03/2007] [Indexed: 10/23/2022]
Abstract
Understanding the basis for the control of myometrial contractant and relaxant signaling pathways is important to understanding how to manage myometrial contractions. Signaling pathways are influenced by the level of expression of the signals and signal pathway components, the location of these components in the appropriate subcellular environment, and covalent modification. Crosstalk between these pathways regulates the effectiveness of signal transduction and represents an important way by which hormones can regulate phenotype. This review deals primarily with signaling pathways that control Ca2+ entry and intracellular release, as well as the interplay between these pathways.
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Affiliation(s)
- Barbara M Sanborn
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1680, USA.
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Li Y, Gallant C, Malek S, Morgan KG. Focal adhesion signaling is required for myometrial ERK activation and contractile phenotype switch before labor. J Cell Biochem 2007; 100:129-40. [PMID: 16888778 DOI: 10.1002/jcb.21033] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In late pregnancy rapidly increasing fetal growth dramatically increases uterine wall tension. This process has been implicated in the activation of the myometrium for labor, but the mechanisms involved are unclear. Here, we tested, using a rat model, the hypothesis that gestation-dependent stretch, via activation of focal adhesion signaling, contributes to the published activation of myometrial ERK at the end of pregnancy. Consistent with this hypothesis, we show here that ERK is targeted to adhesion plaques during late pregnancy. Furthermore, myometrial stretch triggers a dramatic increase in myometrial contractility and ERK and caldesmon phosphorylation, confirming the presence of stretch sensitive myometrial signaling element. Screening by anti-phosphotyrosine immunoblotting for focal adhesion signaling in response to stretch reveals a significant increase in the tyrosine phosphorylated bands identified as focal adhesion kinase (FAK), A-Raf, paxillin, and Src. Pretreatment with PP2, a Src inhibitor, significantly suppresses the stretch-induced increases in FAK, paxillin, Src, ERK and caldesmon phosphorylation and myometrial contractility. Thus, focal adhesion-Src signaling contributes to ERK activation and promotes contraction in late pregnancy. These results point to focal adhesion signaling molecules as potential targets in the modulation of the myometrial contractility and the onset of labor.
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Affiliation(s)
- Yunping Li
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
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16
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Garcia-Verdugo I, Leiber D, Robin P, Billon-Denis E, Chaby R, Tanfin Z. Direct interaction of surfactant protein A with myometrial binding sites: signaling and modulation by bacterial lipopolysaccharide. Biol Reprod 2007; 76:681-91. [PMID: 17202387 DOI: 10.1095/biolreprod.106.058131] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Surfactant protein A (SFTPA1), a member of the collagenous lectin (collectin) family, was first described as a major constituent of lung surfactant, but has recently also been found in the female genital tract. Various microorganisms colonize this area and may cause intrauterine infection or trigger preterm labor. We found that SFTPA1 was not produced in the uterus. Instead, it was immunodetected transiently in rat myometrium at the end (Days 19 and 21) of gestation, but not postpartum, and in cultured myometrial cells. Fluorescence microscopy showed that Texas Red-labeled SFTPA1 bound to myometrial cells. This result was confirmed by biochemical approaches. [(125)I]-SFTPA1 bound to two myometrial cell proteins (55 and 210 kDa). This interaction was dependent on the integrity of the collagenlike domain of SFTPA1. SFTPA1 rapidly activated mitogen-activated protein kinase 1/3 (MAPK1/3) in myometrial cells. Bacterial lipopolysaccharide (LPS), an agent known to trigger uterine contractions and preterm birth, also activated MAPK1/3. The prolonged treatment of myometrial cells with LPS or SFTPA1 upregulated PTGS2 (COX2) protein levels. The addition of rough-type LPS to SFTPA1 blocked the interaction of SFTPA1 with its binding sites and the activation of MAPK1/3 and PTGS2 by SFTPA1. Our data provide the first demonstration of a direct effect of SFTPA1 on rat myometrial cells and inhibitory cross talk between SFTPA1 and LPS signals, providing new insight into the mechanisms of normal and preterm parturition.
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Affiliation(s)
- Ignacio Garcia-Verdugo
- Equipe Endotoxines, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR-8619, Université Paris-Sud, 91400 Orsay, France
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Mewe M, Bauer CK, Schwarz JR, Middendorff R. Mechanisms Regulating Spontaneous Contractions in the Bovine Epididymal Duct1. Biol Reprod 2006; 75:651-9. [PMID: 16855213 DOI: 10.1095/biolreprod.106.054577] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Muscular autorhythmicity provides propulsion of spermatozoa through the epididymal duct, thereby ensuring sperm maturation. In the present study, the mechanisms underlying the bovine epididymal spontaneous phasic contractions (SCs) were analyzed by using muscle-tension recording and patch-clamp techniques. SCs were recorded from the caput, the corpus, and the proximal cauda region and found to be predominantly myogenic in origin. Removal of the luminal fluid induced a burstlike contraction pattern, and removal of the epithelium, a complete loss of SCs. Application of nifedipine, but not heparin and cyclopiazonic acid, suppressed SCs, indicating that influx of Ca2+ through L-type Ca2+ channels, but not Ca2+ release from intracellular stores, was crucial for maintaining SCs. The prostaglandin-endoperoxide synthase 2 (PTGS2) inhibitor NS-398 caused a region-dependent decrease in SCs and tone. These effects were mimicked by the mitogen-activated protein kinase (MAPK) kinase inhibitor PD-98059. Similarly, the prostaglandin F(2alpha) (PGF(2alpha))-receptor antagonist AL-8810 reduced SC generation, whereas PGF(2alpha) induced SC-like activity in epithelium-denuded segments. Cell-isolation experiments revealed the existence of three morphologically different types of contractile cells, which also showed distinct biophysical properties: typical smooth muscle cells in the cauda, myofibroblast-like cells all along the duct, and atypical muscle cells (ATMs) with filament-like spurs in all regions with SCs. These data suggest that the bovine epididymal autorhythmicity is based on an epithelial PTGS2-dependent release of (an) excitatory prostaglandin(s) and a MAPK-dependent activation of L-type Ca2+ channels in the contractile cells. ATM cells may provide electrical coupling between myofibroblasts, which is essential for the generation of regular myogenic activity.
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Affiliation(s)
- Marco Mewe
- Institut für Anatomie II: Experimentelle Morphologie, Zentrum für Experimentelle Medizin, Universitätsklinikum Hamburg-Eppendorf, Universität Hamburg, D-20246 Hamburg, Germany.
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Hillhouse EW, Grammatopoulos DK. The molecular mechanisms underlying the regulation of the biological activity of corticotropin-releasing hormone receptors: implications for physiology and pathophysiology. Endocr Rev 2006; 27:260-86. [PMID: 16484629 DOI: 10.1210/er.2005-0034] [Citation(s) in RCA: 265] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The CRH receptor (CRH-R) is a member of the secretin family of G protein-coupled receptors. Wide expression of CRH-Rs in the central nervous system and periphery ensures that their cognate agonists, the family of CRH-like peptides, are capable of exerting a wide spectrum of actions that underpin their critical role in integrating the stress response and coordinating the activity of fundamental physiological functions, such as the regulation of the cardiovascular system, energy balance, and homeostasis. Two types of mammal CRH-R exist, CRH-R1 and CRH-R2, each with unique splicing patterns and remarkably distinct pharmacological properties, but similar signaling properties, probably reflecting their distinct and sometimes contrasting biological functions. The regulation of CRH-R expression and activity is not fully elucidated, and we only now begin to fully understand the impact on mammalian pathophysiology. The focus of this review is the current and evolving understanding of the molecular mechanisms controlling CRH-R biological activity and functional flexibility. This shows notable tissue-specific characteristics, highlighted by their ability to couple to distinct G proteins and activate tissue-specific signaling cascades. The type of activating agonist, receptor, and target cell appears to play a major role in determining the overall signaling and biological responses in health and disease.
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Affiliation(s)
- Edward W Hillhouse
- The Leeds Institute of Genetics, Health and Therapeutics, The University of Leeds, Leeds LS2 9NL, UK.
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Brant K, Caruso RL. Late-Gestation Rat Myometrial Cells Express Multiple Isoforms of Phospholipase A2 That Mediate PCB 50-Induced Release of Arachidonic Acid with Coincident Prostaglandin Production. Toxicol Sci 2005; 88:222-30. [PMID: 16120751 DOI: 10.1093/toxsci/kfi296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Previous reports have shown that ortho-substituted polychlorinated biphenyls (PCBs) are uterotonic and activate phospholipase A2 to release arachidonic acid (AA) from membrane phospholipids. AA serves as the precursor to various eicosanoids, which, in addition to AA itself, are capable of modulating uterine function. To examine whether PCBs stimulate phospholipase A2 (PLA2) to mobilize arachidonic acid from late-gestation rat uterus, primary cultures of gestation day 20 (gd20) rat myometrial cells (RMC) were labeled with 0.5 microCi 3H-AA prior to a 10-, 20-, or 30-min exposure to 2,2',4,6-tetrachlorobiphenyl (PCB 50) (1-50 microM) or 0.1% DMSO (solvent control). PCB 50 stimulated the release of 3H-AA from gd20 RMC in concentration- and time-dependent manners (p < 0.05). PCB 50 stimulation of RMC was attenuated with ethylene glycol bis(2-aminoethyl ether)-N,N,N'N'-tetraacetic acid (EGTA) and nifedipine, suggesting that AA release was dependent on the influx of extracellular calcium through L-type voltage-operated calcium channels. PCB 50-induced release of AA from RMC was also attenuated with the PLA2-specific inhibitors methyl arachidonyl fluorophosphonate (MAFP), bromoenol lactone (BEL), and manoalide (p < 0.05). Stimulation of PLA2 enzymes in response to PCB exposure occurred via p38 mitogen activated protein kinase (MAPK) activation as indicated by the significant attenuation of PCB 50-induced AA release from RMC in the presence of SB 202190. In addition to stimulating AA release, PCB 50 induced a significant production of prostaglandins from gd20 RMC compared with controls (p < 0.05). These results suggest that myometrial cells express multiple PLA2 isoforms that may serve as a target and effector for ortho-substituted PCB-mediated stimulation of uterine function through arachidonic acid and prostaglandin release.
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Affiliation(s)
- Kelly Brant
- Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan 48109-2029, 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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Li Y, Je HD, Malek S, Morgan KG. Role of ERK1/2 in uterine contractility and preterm labor in rats. Am J Physiol Regul Integr Comp Physiol 2004; 287:R328-35. [PMID: 15072963 DOI: 10.1152/ajpregu.00042.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The present study tested the hypothesis that ERK activation is an essential step in the onset of labor in a rat model of preterm labor. The administration of RU-486, an antiprogesterone agent, to rats induced preterm delivery 22.2 +/- 0.24 h after treatment. Changes in basal signaling events were studied in myometrial tissue from CO(2)-euthanized rats. Rats treated with RU-486 displayed a dramatically increased in vitro uterine contractility compared with gestational stage-matched, sham-treated rats. In vitro contractility was not significantly different from that during spontaneous labor. During RU-486-induced preterm labor, as previously described for spontaneous labor, ERK phosphorylation levels increased, as did phosphorylation of caldesmon at Ser(789), an ERK phosphorylation site. Also, a small but significant increase in 20-kDa myosin light chain phosphorylation was seen at a constant intracellular pCa of 7. When rats were chronically treated with an agent that prevents ERK activation, U-0126, the onset of RU-486-induced preterm labor was delayed in a statistically significant manner. Chronic in vivo treatment with U-0126 also significantly inhibited the RU-486-induced increase in in vitro contractility and ERK and caldesmon phosphorylation but did not alter the RU-486-induced increase in 20-kDa myosin light chain phosphorylation. These data indicate that ERK activation is a component of the multiple events leading to the development of labor in this rat model. We suggest that the ERK pathway could possibly be used to identify targets for the development of a novel class of tocolytic agents.
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Affiliation(s)
- Yunping Li
- Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston 02215, USA.
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Mabuchi S, Ohmichi M, Kimura A, Ikebuchi Y, Hisamoto K, Arimoto-Ishida E, Nishio Y, Takahashi K, Tasaka K, Murata Y. Tamoxifen inhibits cell proliferation via mitogen-activated protein kinase cascades in human ovarian cancer cell lines in a manner not dependent on the expression of estrogen receptor or the sensitivity to cisplatin. Endocrinology 2004; 145:1302-13. [PMID: 14645110 DOI: 10.1210/en.2003-0709] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although tamoxifen (TAM), which is widely used in the treatment of breast cancer, also has a beneficial effect on cisplatin-refractory ovarian cancer, the biological mechanism of this effect has remained obscure. TAM, besides its action as an antiestrogen, also inhibits cell proliferation of estrogen receptor (ER)-negative cells by an unknown mechanism. Therefore, we examined the roles of the MAPK family in the antiproliferative effect of TAM on cisplatin-resistant Caov-3, which expresses ER and cisplatin-sensitive A2780, which does not express ER. The number of viable cells was reduced by TAM dose-dependently. TAM induced the activation of ERK, c-Jun N-terminal protein kinase (JNK), and p38 with different time courses. PD98059 canceled the reduction of the number of viable cells by 1 microM TAM and inhibited the TAM-induced cell-cycle arrest at the G(1) phase and dephosphorylation of the retinoblastoma protein. Either expression of dominant-negative JNK or pretreatment with SB203580 canceled the reduction of the number of viable cells by 5 microM TAM and inhibited the apoptotic nuclear changes and the cleavage of poly (ADP-ribose) polymerase induced by TAM. These results provide evidence that whereas the ERK cascade is involved in the induction of cell-cycle arrest at the G(1) phase by lower concentrations of TAM, the JNK or p38 cascade is involved in the induction of apoptosis by higher concentrations of TAM in both types of cells.
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Affiliation(s)
- Seiji Mabuchi
- Departmentof Obstetrics and Gynecology, Osaka University Medical School, Suita, Osaka 565-0871, Japan
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Robin P, Boulven I, Desmyter C, Harbon S, Leiber D. ET-1 stimulates ERK signaling pathway through sequential activation of PKC and Src in rat myometrial cells. Am J Physiol Cell Physiol 2002; 283:C251-60. [PMID: 12055094 DOI: 10.1152/ajpcell.00601.2001] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this study, we analyzed in rat myometrial cells the signaling pathways involved in the endothelin (ET)-1-induced extracellular signal-regulated kinase (ERK) activation required for the induction of DNA synthesis. We found that inhibition of protein kinase C (PKC) by Ro-31-8220 abolished ERK activation. Inhibition of phospholipase C (PLC) by U-73122 or of phosphoinositide (PI) 3-kinase by wortmannin partially reduced ERK activation. A similar partial inhibition was observed after treatment with pertussis toxin or PKC downregulation by phorbol ester treatment. The effect of wortmannin was additive with that produced by PKC downregulation but not with that due to pertussis toxin. These results suggest that both diacylglycerol-sensitive PKC, activated by PLC products, and diacylglycerol-insensitive PKC, possibly activated by a G(i)-PI 3-kinase-dependent process, are involved in ET-1-induced ERK activation. These two pathways were found to be activated mainly through the ET(A) receptor subtype. ET-1 and phorbol ester stimulated Src activity in a PKC-dependent manner, both responses being abolished in the presence of Ro-31-8220. Inhibition of Src kinases by PP1 abrogated phorbol ester- and ET-1-induced ERK activation. Finally, ET-1 activated Ras in a PP1- and Ro-31-8220-sensitive manner. Altogether, our results indicate that ET-1 induces ERK activation in rat myometrial cells through the sequential stimulation of PKC, Src, and Ras.
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Affiliation(s)
- Philippe Robin
- Laboratoire de Signalisation et Régulations Cellulaires, Centre National de la Recherche Scientifique Unité Mixte de Recherche 8619, Université de Paris-Sud, 91405 Orsay cedex, France
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Hillhouse EW, Grammatopoulos DK. Characterising the corticotropin-releasing hormone (CRH) receptors mediating CRH and urocortin actions during human pregnancy and labour. Stress 2001; 4:235-46. [PMID: 22432144 DOI: 10.3109/10253890109014748] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mechanism of human labour remains unresolved. One of the most important regulatory signals, however, appears to be corticotropin-releasing hormone (CRH), a hypothalamic peptide that controls the body's response to stress, which is also produced by the placenta and intrauterine tissues during pregnancy. CRH belongs to a family of peptides that includes urocortin, which shares sequence homology with CRH and is also expressed by the placenta and intrauterine tissues. During human pregnancy circulating CRH appears to have five main target tissues: the myometrium, the placenta, the fetal membranes, the fetal adrenal cortex and the vasculature. In these tissues CRH plays a role in the control of myometrial contractility,placenta vasodilation, peptide and prostaglandin production and adrenal steroidogenesis and probably many more, yet unidentified processes. The actions of CRH in these tissues are mediated via specific G-protein coupled membrane-bound receptors. These receptors have different functional characteristics, depending on where they are expressed and on the stage of pregnancy. In addition, their function depends upon other intracellular signals via communication between signalling cascades. These findings led us to propose a hypothesis for a dual role of CRH and other CRH-like peptides during pregnancy and labour.
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Affiliation(s)
- E W Hillhouse
- The Sir Quinron Hazel1 Molecular Medicine Research Centre, Department of Biological Sciences, The University of Warwick, Coventry, UK.
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Takanami-Ohnishi Y, Asada S, Tsunoda H, Fukamizu A, Goto K, Yoshikawa H, Kubo T, Sudo T, Kimura S, Kasuya Y. Possible involvement of p38 mitogen-activated protein kinase in decidual function in parturition. Biochem Biophys Res Commun 2001; 288:1155-61. [PMID: 11700032 DOI: 10.1006/bbrc.2001.5895] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We designed the present study to elucidate the molecular mechanism for parturition, focusing on p38 mitogen-activated protein kinase (p38). The kinase activity of p38 in mouse uterus was gestation stage-dependent, and was markedly increased on day 19 of gestation and during labor. Immunohistochemical examination with anti-phospho p38 antibody revealed that activated p38 was predominantly localized in decidual stromal cells stained with anti-prolactin antibody. In human primary cultured decidual cells, a p38 inhibitor, SB202190, significantly inhibited both prostaglandin F(2alpha) production and COX-2 expression induced by stimulation with IL-1beta. These results suggest that the p38 signaling pathway is involved in decidual function at the late stage of gestation and may contribute to parturition.
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Affiliation(s)
- Y Takanami-Ohnishi
- Department of Biochemistry and Molecular Pharmacology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
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Abdel-Latif AA. Cross talk between cyclic nucleotides and polyphosphoinositide hydrolysis, protein kinases, and contraction in smooth muscle. Exp Biol Med (Maywood) 2001; 226:153-63. [PMID: 11361033 DOI: 10.1177/153537020122600302] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This article provides an update of a minireview published in 1996 (Abdel-Latif AA. Proc Soc Exp Biol Med 211:163-177, 1996), the purpose of which was to examine in nonvascular smooth muscle the biochemical and functional cross talk between the sympathetic nervous system, which governs the formation of cAMP and muscle relaxation, and the parasympathetic nervous system, which governs the generation of IP3 and diacylglycerol, from the polyphosphoinositides, Ca2+ mobilization, and contraction. This review examines further evidence, both from nonvascular and vascular smooth muscle, for cross talk between the cyclic nucleotides, cAMP and cGMP via their respective protein kinases, and the Ca2+-dependent- and Ca2+-independent-signaling pathways involved in agonist-induced contraction. These include the IP3-Ca2+-CaM- myosin light chain kinase (MLCK) pathway and the Ca2+-independent pathways, including protein kinase C-, MAP kinase-, and Rho-kinase. In addition, MLC phosphorylation and contraction can also be increased by a decrease in myosin phosphatase activity. A summary of the cross talk between the cyclic nucleotides and these signaling pathways was presented. In smooth muscle, there are several targets for cyclic nucleotide inhibition and consequent relaxation, including the receptor, G proteins, phospholipase C-beta1-4 isoforms, IP3 receptor, Ca2+ mobilization, MLCK, MAP kinase, Rho-kinase, and myosin phosphatase. While significant progress has been made in the past four years on this cross talk, the precise mechanisms underlying the biochemical basis for the cyclic nucleotide inhibition of Ca2+ mobilization and consequently muscle contraction remain to be established. Although it is well established that second-messenger cross talk plays an important role in smooth muscle relaxation, the many sources which exist in smooth muscle for Ca2+ mobilization, coupled with the multiple signaling pathways involved in agonist-induced contraction, contribute appreciably to the difficulties found by many investigators in identifying the targets for cyclic nucleotide inhibition and consequent relaxation. Better methodology and more novel interdisciplinary approaches are required for elucidating the mechanism(s) of cAMP- and cGMP-inhibition of smooth muscle contraction.
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Affiliation(s)
- A A Abdel-Latif
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta 30912, USA.
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Chen D, Fong HW, Davis JS. Induction of c-fos and c-jun messenger ribonucleic acid expression by prostaglandin F2alpha is mediated by a protein kinase C-dependent extracellular signal-regulated kinase mitogen-activated protein kinase pathway in bovine luteal cells. Endocrinology 2001; 142:887-95. [PMID: 11159862 DOI: 10.1210/endo.142.2.7938] [Citation(s) in RCA: 48] [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
PGF2alpha triggers the demise of the corpus luteum whereby progesterone synthesis is inhibited, the luteal structure regresses, and the estrus cycle resumes. Upon binding to its heterotrimeric G-protein-coupled receptors, PGF2alpha initiates the phospholipase C/diacylglycerol and inositol-1,4,5-trisphosphate/Ca(2+)-protein kinase C (PKC) signaling pathway. More recently, we have demonstrated that PGF2alpha activates extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase signaling through a Raf-dependent mechanism in bovine luteal cells. However, the relationship between PKC and ERK activation in PGF2alpha signaling has not been clearly defined. Moreover, the signaling pathway that PGF2alpha uses to regulate gene expression is unknown. In this report, primary cultures of bovine luteal cells were used to address the role of PKC in ERK activation and the signaling pathway for induction of c-fos and c-jun messenger RNA (mRNA) expression in response to PGF2alpha. By using a PKC inhibitor and a PKC-deficient luteal cell model, we observed that phorbol ester-responsive isoforms of PKC were required for ERK phosphorylation and activation by PGF2alpha (1 microM) or phorbol 12-myristate 13-acetate (PMA) (20 nM). In PGF2alpha- and PMA-treated cells, active ERK MAP kinase was localized in the nucleus. PGF2alpha-induced ERK phosphorylation was dose-dependently inhibited by the MEK1 inhibitor PD098059 (1-50 microM). The expression of c-fos and c-jun mRNA in luteal cells was markedly increased by treatment with PGF2alpha (1 microM) or PMA (20 nM) for 30 min. We also observed that activation of ERK MAP kinase was required for the expression of c-fos and c-jun mRNA in response to PGF2alpha and PMA because it was abrogated by blocking the ERK pathway with PD098059. In addition, PGF2alpha and PMA-induced c-fos and c-jun mRNA expression was abolished in the PKC-deficient cells. Taken together, our data demonstrate that a PKC-dependent ERK MAP kinase pathway mediates the expression of c-fos and c-jun mRNA in PGF2alpha-treated bovine luteal cells.
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Affiliation(s)
- D Chen
- The Women's Research Institute, Department of Obstetrics and Gynecology, University of Kansas School of Medicine-Wichita, Kansas 67214, USA
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Yang ZW, Wang J, Zheng T, Altura BT, Altura BM. Ethanol-induced contractions in cerebral arteries: role of tyrosine and mitogen-activated protein kinases. Stroke 2001; 32:249-57. [PMID: 11136944 DOI: 10.1161/01.str.32.1.249] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The relationship between alcohol consumption and stroke appears complex; moderate ingestion is associated with reduced stroke risk, while heavy intake is associated with increased stroke risk. Ethanol has been shown both experimentally and epidemiologically to induce hemorrhagic and ischemic strokes, which are associated with cerebral vasoconstriction. Ethanol is known to induce contraction in isolated cerebral arteries and intact microvessels from diverse mammalian animals. The relationships between ethanol-induced contractions in cerebral arteries, intracellular free Ca(2+) ([Ca(2+)](i)), tyrosine kinases (including the src family), and mitogen-activated protein kinases (MAPK) were investigated in the present study. METHODS Cerebral arterial muscle tension and [Ca(2+)](i) were quantified by an isometric contraction technique and direct visualization of Ca(2+) in single cells. RESULTS Ethanol induces concentration-dependent contractions in intact canine basilar arteries, which are attenuated significantly by pretreatment of the arteries with low concentrations of an antagonist of protein tyrosine kinases (genistein); an src homology 2 (SH2) domain inhibitor peptide; a highly specific antagonist of p38 MAPK (SB-203580); a potent, selective antagonist of MEK1/MEK2 (U0126); and a selective antagonist of mitogen-activated protein kinase kinase (MAPKK) (PD-98059). IC(50) levels obtained for these 5 antagonists are consistent with reported K:(i) values for these tyrosine kinase, MAPK, and MAPKK antagonists. Ethanol induces transient and sustained increases in [Ca(2+)](i) in primary single smooth muscle cells from canine basilar arteries, which are markedly attenuated in the presence of genistein, an SH2 domain inhibitor peptide, SB-203580, U0126, and PD-98059. Several specific antagonists of known endogenously formed vasoconstrictors do not inhibit or attenuate either the ethanol-induced contractions or the elevation of [Ca(2+)](i). CONCLUSIONS The present study suggests that activation of protein tyrosine kinases (including the src family) and MAPK appear to play important roles in the ethanol-induced contractions and the elevation of [Ca(2+)](i) in smooth muscle cells from canine basilar arteries. The results could be used to suggest that selective antagonists of protein tyrosine kinases and MAPK may be useful both prophylactically and therapeutically in alcohol-induced strokes.
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Affiliation(s)
- Z W Yang
- Department of Physiology and Pharmacology, State University of New York, Health Science Center at Brooklyn, Brooklyn, NY 11203, USA
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Cheng KW, Leung PCK. The expression, regulation and signal transduction pathways of the mammalian gonadotropin-releasing hormone receptor. Can J Physiol Pharmacol 2000. [DOI: 10.1139/y00-096] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Normal mammalian sexual maturation and reproductive functions require the integration and precise coordination of hormones at the hypothalamic, pituitary, and gonadal levels. Hypothalamic gonadotropin-releasing hormone (GnRH) is a key regulator in this system; after binding to its receptor (GnRHR), it stimulates de novo synthesis and release of gonadotropins in anterior pituitary gonadotropes. Since the isolation of the GnRHR cDNA, the expression of GnRHR mRNA has been detected not only in the pituitary, but also in extrapituitary tissues, including the ovary and placenta. It has been shown that change in GnRHR mRNA is one of the mechanisms for regulating the expression of the GnRHR. To help understand the molecular mechanism(s) involved in transcriptional regulation of the GnRHR gene, the 5' flanking region of the GnRHR gene has recently been isolated. Initial characterization studies have identified several DNA regions in the GnRHR 5' flanking region which are responsible for both basal expression and GnRH-mediated homologous regulation of this gene in pituitary cells. The mammalian GnRHR lacks a C-terminus and possesses a relatively short third intracellular loop; both features are important in desensitization of many others G-protein coupled receptors (GPCRs), Homologous desensitization of GnRHR has been shown to be regulated by various serine-threonine protein kinases including protein kinase A (PKA) and protein kinase C (PKC), as well as by G-protein coupled receptor kinases (GRKs). Furthermore, GnRHR was demonstrated to couple with multiple G proteins (Gq/11, Gs, and Gi), and to activate cascades that involved the PKC, PKA, and mitogen-activator protein kinases. These results suggest the diversity of GnRHR-G protein coupling and signal transduction systems. The identification of second form of GnRH (GnRH-II) in mammals adds to the complexity of the GnRH-GnRHR system. This review summaries our recent progress in understanding the regulation of GnRHR gene expression and the GnRHR signal transduction pathways.Key words: gonadotropin-releasing hormone receptor, transcriptional regulation, desensitization, signal transduction.
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Yokoi T, Ohmichi M, Tasaka K, Kimura A, Kanda Y, Hayakawa J, Tahara M, Hisamoto K, Kurachi H, Murata Y. Activation of the luteinizing hormone beta promoter by gonadotropin-releasing hormone requires c-Jun NH2-terminal protein kinase. J Biol Chem 2000; 275:21639-47. [PMID: 10787426 DOI: 10.1074/jbc.m910252199] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Regulation of the mitogen-activated protein kinase (MAPK) family by gonadotropin-releasing hormone (GnRH) in the gonadotrope cell line LbetaT2 was investigated. Treatment with gonadotropin-releasing hormone agonist (GnRHa) activates extracellular signal-regulated kinase (ERK) and c-Jun NH(2)-terminal kinase (JNK). Activation of ERK by GnRHa occurred within 5 min, and declined thereafter, whereas activation of JNK by GnRHa occurred with a different time frame, i.e. it was detectable at 5 min, reached a plateau at 30 min, and declined thereafter. GnRHa-induced ERK activation was dependent on protein kinase C or extracellular and intracellular Ca(2+), whereas GnRHa-induced JNK activation was not dependent on protein kinase C or on extracellular or intracellular Ca(2+). To determine whether a mitogen-activated protein kinase family cascade regulates rat luteinizing hormone beta (LHbeta) promoter activity, we transfected the rat LHbeta (-156 to +7)-luciferase construct into LbetaT2 cells. GnRH activated the rat LHbeta promoter activity in a time-dependent manner. Neither treatment with a mitogen-activated protein kinase/ERK kinase (MEK) inhibitor, PD98059, nor cotransfection with a catalytically inactive form of a mitogen-activated protein kinase construct inhibited the induction of the rat LHbeta promoter by GnRH. Furthermore, cotransfection with a dominant negative Ets had no effect on the response of the rat LHbeta promoter to GnRH. On the other hand, cotransfection with either dominant negative JNK or dominant negative c-Jun significantly inhibited the induction of the rat LHbeta promoter by GnRH. In addition, GnRH did not induce either the rat LHbeta promoter activity in LbetaT2 cells transfected stably with dominant negative c-Jun. These results suggest that GnRHa differentially activates ERK and JNK, and a JNK cascade is necessary to elicit the rat LHbeta promoter activity in a c-Jun-dependent mechanism in LbetaT2 cells.
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Affiliation(s)
- T Yokoi
- Department of Obstetrics and Gynecology, Osaka University Medical School, 2-2, Yamadaoka, Suita, Osaka 565-0871, Japan
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Kimura A, Ohmichi M, Tasaka K, Kanda Y, Ikegami H, Hayakawa J, Hisamoto K, Morishige K, Hinuma S, Kurachi H, Murata Y. Prolactin-releasing peptide activation of the prolactin promoter is differentially mediated by extracellular signal-regulated protein kinase and c-Jun N-terminal protein kinase. J Biol Chem 2000; 275:3667-74. [PMID: 10652364 DOI: 10.1074/jbc.275.5.3667] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Regulation of the mitogen-activated protein kinase (MAPK) family by prolactin-releasing peptide (PrRP) in both GH3 rat pituitary tumor cells and primary cultures of rat anterior pituitary cells was investigated. PrRP rapidly and transiently activated extracellular signal-regulated protein kinase (ERK) in both types of cells. Both pertussis toxin, which inactivates G(i)/G(o) proteins, and exogenous expression of a peptide derived from the carboxyl terminus of the beta-adrenergic receptor kinase I, which specifically blocks signaling mediated by the betagamma subunits of G proteins, completely blocked the PrRP-induced ERK activation, suggesting the involvement of G(i)/G(o) proteins in the PrRP-induced ERK activation. Down-regulation of cellular protein kinase C did not significantly inhibit the PrRP-induced ERK activation, suggesting that a protein kinase C-independent pathway is mainly involved. PrRP-induced ERK activation was not dependent on either extracellular Ca(2+) or intracellular Ca(2+). However, the ERK cascade was not the only route by which PrRP communicated with the nucleus. JNK was also shown to be significantly activated in response to PrRP. JNK activation in response to PrRP was slower than ERK activation. Moreover, to determine whether a MAPK family cascade regulates rat prolactin (rPRL) promoter activity, we transfected the intact rPRL promoter ligated to the firefly luciferase reporter gene into GH3 cells. PrRP activated the rPRL promoter activity in a time-dependent manner. Co-transfection with a catalytically inactive form of a MAPK construct or a dominant negative JNK, partially but significantly inhibited the induction of the rPRL promoter by PrRP. Furthermore, co-transfection with a dominant negative Ets completely abolished the response of the rPRL promoter to PrRP. These results suggest that PrRP differentially activates ERK and JNK, and both cascades are necessary to elicit rPRL promoter activity in an Ets-dependent mechanism.
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Affiliation(s)
- A Kimura
- Department of Obstetrics, Osaka University Medical School, 2-2, Yamadaoka, Suita, Osaka 565-0871, Japan
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Masuhara K, Ohmichi M, Kurachi H, Tasaka K, Kanzaki T, Kimura A, Hayakawa J, Hisamoto K, Koike K, Murata Y. Involvement of extracellular signal-regulated protein kinase in gliosis induced during recovery from metabolic inhibition. Biochem Biophys Res Commun 2000; 267:892-6. [PMID: 10673387 DOI: 10.1006/bbrc.1999.2053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Brain reperfusion may be of particular importance in the etiology of periventricular leukomalacia, of which the common findings are gliosis and ventricular dilatation. To investigate the mechanism of this pathogenesis, we used a metabolic inhibition (MI) model using cyanide plus deoxyglucose treatment of cultured glia isolated from fetal rat brain and examined the activity of extracellular signal-regulated protein kinase (ERK) during MI and also during the recovery from MI of 30 min. ERK activation was stimulated during MI and the recovery from MI. The time course and extent of activation of ERK during MI and the recovery from MI, however, were distinctly different. Activation of ERK was stimulated within 5 min of MI and declined thereafter. Activation of ERK was sustained during the recovery phase from MI and the extent of the activation was much greater than that during MI. Pretreatment with EGTA to eliminate extracellular Ca(2+), or with APV, an NMDA receptor antagonist, to inhibit Ca(2+) influx through the NMDA receptor, attenuated the activation of ERK. Moreover, pretreatment with PMA to downregulate PKC abolished the activation of ERK. PD98059, an inhibitor of ERK kinase, attenuated the cell proliferation induced by MI followed by recovery from MI. These results suggest that ERK is involved in gliosis during the recovery phase from MI and may play a role in the etiology of periventricular leukomalacia.
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Affiliation(s)
- K Masuhara
- Department of Obstetrics, Osaka University Medical School, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan.
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Hayakawa J, Ohmichi M, Kurachi H, Ikegami H, Kimura A, Matsuoka T, Jikihara H, Mercola D, Murata Y. Inhibition of extracellular signal-regulated protein kinase or c-Jun N-terminal protein kinase cascade, differentially activated by cisplatin, sensitizes human ovarian cancer cell line. J Biol Chem 1999; 274:31648-54. [PMID: 10531373 DOI: 10.1074/jbc.274.44.31648] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have studied the roles of c-Jun N-terminal protein kinase (JNK) and extracellular signal-regulated protein kinase (ERK) cascade in both the cisplatin-resistant Caov-3 and the cisplatin-sensitive A2780 human ovarian cancer cell lines. Treatment of both cells with cisplatin but not transplatin isomer activates JNK and ERK. Activation of JNK by cisplatin occurred at 30 min, reached a plateau at 3 h, and declined thereafter, whereas activation of ERK by cisplatin showed a biphasic pattern, indicating the different time frame. Activation of JNK by cisplatin was maximal at 1000 microM, whereas activation of ERK was maximal at 100 microM and was less at higher concentrations, indicating the different dose dependence. Cisplatin-induced JNK activation was neither extracellular and intracellular Ca(2+)- nor protein kinase C-dependent, whereas cisplatin-induced ERK activation was extracellular and intracellular Ca(2+)- dependent and protein kinase C-dependent. A mitogen-activated protein kinase/extracellular signal-regulated kinase kinase inhibitor, PD98059, had no effect on the cisplatin-induced JNK activity, suggesting an absence of cross-talk between the ERK and JNK cascades. We further examined the effect of each cascade on the viability following cisplatin treatment. Either exogenous expression of dominant negative c-Jun or the treatment by PD98059 induced sensitivity to cisplatin in both cells. Our findings suggest that cisplatin-induced DNA damage differentially activates JNK and ERK cascades and that inhibition of either of these cascades sensitizes ovarian cancer cells to cisplatin.
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Affiliation(s)
- J Hayakawa
- Department of Obstetrics, Osaka University Medical School, 2-2, Yamadaoka, Suita, Osaka 565-0871, Japan
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Kimura A, Ohmichi M, Takeda T, Kurachi H, Ikegami H, Koike K, Masuhara K, Hayakawa J, Kanzaki T, Kobayashi M, Akabane M, Inoue M, Miyake A, Murata Y. Mitogen-activated protein kinase cascade is involved in endothelin-1-induced rat puerperal uterine contraction. Endocrinology 1999; 140:722-31. [PMID: 9927299 DOI: 10.1210/endo.140.2.6477] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The regulation of mitogen-activated protein (MAP) kinase by endothelin-1 (ET-1) in cultured rat puerperal uterine myometrial cells was investigated. ET-1 caused the rapid stimulation of MAP kinase activity. ET-1-induced MAP kinase activation is neither extracellular Ca2+- nor intracellular Ca2+-dependent. ET-1 stimulation also led to an increase in phosphorylation of son-of-sevenless (SOS), and transfection of dominant negative SOS attenuated the ET-1-induced MAP kinase activity. Phorbol-12-myristate 13-acetate (PMA) also induced the MAP kinase activity, but pretreatment of the cultured cells with PMA, to down-regulate protein kinase C (PKC), did not abolish the activation of MAP kinase by ET-1. In addition, down-regulation of PKC had no effect on ET-1-induced SOS phosphorylation. Pertussis toxin, which inactivates Gi/Go proteins, blocked the ET-1-induced MAP kinase activation but not the PMA-induced MAP kinase activation. The results suggested that MAP kinase is acutely activated by ET-1 through a pertussis toxin-sensitive G protein and SOS, not through the PMA-sensitive PKC. In addition, although reverse-transcriptase PCR assays detected messenger RNA for both ET- 1 receptor subtypes in cultured rat puerperal uterine myometrial cells, ET-1-induced MAP kinase activity and uterine contraction were blocked by treatment with BQ485, an antagonist selective for an ET type A receptor (but not by BQ788, an ET type B receptor antagonist). Ritodrine, which is known to relax uterine muscle contraction, attenuated ET-1-induced MAP kinase activity. We further examined the role of MAP kinase pathway in uterine contraction using an inhibitor of MEK activity, PD098059. This inhibitor completely inhibited the ET-1-induced MAP kinase activation and partially, but significantly, inhibited the ET-1-induced uterine contraction. These results indicate that ET-1-induced MAP kinase signaling cascade may play an important role in the ET-1-induced uterine contraction.
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Affiliation(s)
- A Kimura
- Department of Obstetrics and Gynecology, Osaka University Medical School, Suita, Japan
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Yuryev A, Wennogle LP. The RAF family: an expanding network of post-translational controls and protein-protein interactions. Cell Res 1998; 8:81-98. [PMID: 9669024 DOI: 10.1038/cr.1998.9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Protein kinase RAF is strategically located in the "Ras-MAP-kinase signal transduction pathway", a principle system which transmits signals from growth factor receptors to the nucleus, resulting in cell proliferation. Growth factor responses are mediated in part by activation of Ras, which in turn activates RAF to phosphorylate MEK, its downstream substrate. MEK activates MAP-kinase to influence nuclear events. It is clear, however, that a network of signals other than those carried by Ras plays a role in RAF regulation. These orthogonal influences are mediated by: serine/threonine kinases, tyrosine kinases, and protein-protein interactions. As a further complication to the RAF network, three isoforms of RAF have been established which have divergent N-terminal regulatory domains. Whereas these divergent regulatory domains implicate isoform-specific functions, no clear evidence or hypothesis for distinct functions for individual isoforms has been presented. Recently, "isoform-specific protein interactions" have been identified among numerous proteins interacting with RAF. These studies may serve to delineate independent functions for RAF isoforms.
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Affiliation(s)
- A Yuryev
- Novartis Pharmaceuticals Corporation, Summit, NJ 07901, USA.
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Sawada T, Ohmichi M, Koike K, Kanda Y, Kimura A, Masuhara K, Ikegami H, Inoue M, Miyake A, Murata Y. Norepinephrine stimulates mitogen-activated protein kinase activity in GT1-1 gonadotropin-releasing hormone neuronal cell lines. Endocrinology 1997; 138:5275-81. [PMID: 9389511 DOI: 10.1210/endo.138.12.5610] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The GT1-1 GnRH neuronal cell lines exhibit highly differentiated properties of GnRH neurons. We have used GT1-1 cells to study the roles of norepinephrine (NE), membrane depolarization, calcium influx, and phorbol esters in the regulation of mitogen-activated protein (MAP) kinase. NE, which is known to stimulate the release of GnRH, induced MAP kinase activity, the tyrosine phosphorylation of MAP kinase, and MAP kinase kinase activity. Forskolin led to activation of MAP kinase comparable with that induced by NE, and a selective inhibitor of cAMP-dependent protein kinase, H8, attenuated the NE-induced activation of MAP kinase. On the other hand, elimination of extracellular calcium by EGTA completely blocked NE-induced tyrosine phosphorylation of MAP kinase, and a selective inhibitor of calcium/calmodulin-dependent protein kinase, KN-62, attenuated the NE-induced activation of MAP kinase. Furthermore, depolarization of GT1-1 cells with 75 mM KCl, 10 microM BayK 8644, or 1 microM calcium ionophore (A23187) induced rapid tyrosine phosphorylation of MAP kinase. The omission of calcium from the extracellular medium completely abolished these effects of tyrosine phosphorylation of MAP kinase. Phorbol 12-myristate 13-acetate (PMA) also induced MAP kinase activity, but pretreatment of the cultured cells with PMA to down-regulate protein kinase C did not abolish the activation of MAP kinase by NE. In addition, although phosphorylation of Raf-1 kinase was stimulated by PMA, this phosphorylation was not induced by either NE or A23187. These results demonstrate that NE activates MAP kinase directly in GT1-1 cells, and that the effect of NE is mediated by increase in the cAMP level and by calcium influx, but not by PMA-sensitive protein kinase C or Raf-1 kinase.
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Affiliation(s)
- T Sawada
- Department of Obstetrics and Gynecology, Osaka University Medical School, Suita, Japan
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