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Almohanna AM, Noble K, Wray S. Extracellular acidification increases uterine contraction in pregnant mouse by increasing intracellular calcium. Acta Physiol (Oxf) 2024; 240:e14147. [PMID: 38650469 DOI: 10.1111/apha.14147] [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: 10/10/2023] [Revised: 03/07/2024] [Accepted: 04/05/2024] [Indexed: 04/25/2024]
Abstract
AIMS As uterine extracellular pH decreases during the ischemic conditions of labor, but its effects on myometrial contraction are largely unknown, there is a need to elucidate its physiological effects and mechanisms of action. Furthermore, it is not known if any of the effects of extracellular acidification are affected by pregnancy, thus we also determined how gestation affects the response to acidification. METHODS Nonpregnant, mid-, and term-pregnant myometrial strips were obtained from humanely killed mice. Contractions were recorded under spontaneous, depolarized, and oxytocin-stimulated conditions. The extracellular pH of the perfusate was changed from 7.4 to 6.9 or 7.9 in HEPES-buffered physiological saline. Intracellular pH was measured using SNARF, and intracellular calcium was measured using Indo-1. Statistical differences were tested using the appropriate t-test. RESULTS Extracellular acidification significantly increased the frequency and amplitude of spontaneous contractions in pregnant, but not nonpregnant, myometrium, whereas alkalinization decreased contractions. Intracellular acidification, via Na-butyrate, transiently increased force in pregnant tissue. Intracellular pH was gradually acidified when extracellular pH was acidified, but extracellular acidification increased contractility before any significant change in intracellular pH. If myometrial force was driven by oxytocin or high-K depolarization, then extracellular pH did not further increase force. Intracellular calcium changes mirrored those of force in the spontaneously contracting pregnant myometrium, and if calcium entry was prevented by nifedipine, extracellular acidification could not induce a rise in force. CONCLUSION Extracellular acidification increases excitability, calcium entry, and thus force in pregnant mouse myometrium, and this may contribute to increasing contractions during labor when ischemic conditions and acidemia occur.
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Affiliation(s)
- Asmaa M Almohanna
- Department of Basic Science, College of Medicine, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Karen Noble
- Department of Veterinary Anatomy, Physiology and Pathology Institute of Infection, Veterinary and Ecological Sciences University of Liverpool, Liverpool, UK
| | - Susan Wray
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
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2
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Voorsluijs V, Avanzini F, Falasco G, Esposito M, Skupin A. Calcium oscillations optimize the energetic efficiency of mitochondrial metabolism. iScience 2024; 27:109078. [PMID: 38375217 PMCID: PMC10875125 DOI: 10.1016/j.isci.2024.109078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 12/26/2023] [Accepted: 01/26/2024] [Indexed: 02/21/2024] Open
Abstract
Energy transduction is central to living organisms, but the impact of enzyme regulation and signaling on its thermodynamic efficiency is generally overlooked. Here, we analyze the efficiency of ATP production by the tricarboxylic acid cycle and oxidative phosphorylation, which generate most of the chemical energy in eukaryotes. Calcium signaling regulates this pathway and can affect its energetic output, but the concrete energetic impact of this cross-talk remains elusive. Calcium enhances ATP production by activating key enzymes of the tricarboxylic acid cycle while calcium homeostasis is ATP-dependent. We propose a detailed kinetic model describing the calcium-mitochondria cross-talk and analyze it using nonequilibrium thermodynamics: after identifying the effective reactions driving mitochondrial metabolism out of equilibrium, we quantify the mitochondrial thermodynamic efficiency for different conditions. Calcium oscillations, triggered by extracellular stimulation or energy deficiency, boost the thermodynamic efficiency of mitochondrial metabolism, suggesting a compensatory role of calcium signaling in mitochondrial bioenergetics.
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Affiliation(s)
- Valérie Voorsluijs
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 avenue du Swing, 4367 Belvaux, Luxembourg
- Complex Systems and Statistical Mechanics, Department of Physics and Materials Science, University of Luxembourg, 162 A avenue de la Faïencerie, 1511 Luxembourg, Luxembourg
| | - Francesco Avanzini
- Complex Systems and Statistical Mechanics, Department of Physics and Materials Science, University of Luxembourg, 162 A avenue de la Faïencerie, 1511 Luxembourg, Luxembourg
- Department of Chemical Sciences, University of Padova, 1 Via F. Marzolo, 35131 Padova, Italy
| | - Gianmaria Falasco
- Complex Systems and Statistical Mechanics, Department of Physics and Materials Science, University of Luxembourg, 162 A avenue de la Faïencerie, 1511 Luxembourg, Luxembourg
- Department of Physics and Astronomy, University of Padova, 8 Via F. Marzolo, 35131 Padova, Italy
| | - Massimiliano Esposito
- Complex Systems and Statistical Mechanics, Department of Physics and Materials Science, University of Luxembourg, 162 A avenue de la Faïencerie, 1511 Luxembourg, Luxembourg
| | - Alexander Skupin
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 avenue du Swing, 4367 Belvaux, Luxembourg
- Department of Physics and Materials Science, University of Luxembourg, 162 A avenue de la Faïencerie, 1511 Luxembourg, Luxembourg
- Department of Neuroscience, University of California, San Diego, 9500 Gilman Drive, San Diego, CA 92093, USA
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3
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Longden TA, Lederer WJ. Electro-metabolic signaling. J Gen Physiol 2024; 156:e202313451. [PMID: 38197953 PMCID: PMC10783436 DOI: 10.1085/jgp.202313451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/27/2023] [Accepted: 12/14/2023] [Indexed: 01/11/2024] Open
Abstract
Precise matching of energy substrate delivery to local metabolic needs is essential for the health and function of all tissues. Here, we outline a mechanistic framework for understanding this critical process, which we refer to as electro-metabolic signaling (EMS). All tissues exhibit changes in metabolism over varying spatiotemporal scales and have widely varying energetic needs and reserves. We propose that across tissues, common signatures of elevated metabolism or increases in energy substrate usage that exceed key local thresholds rapidly engage mechanisms that generate hyperpolarizing electrical signals in capillaries that then relax contractile elements throughout the vasculature to quickly adjust blood flow to meet changing needs. The attendant increase in energy substrate delivery serves to meet local metabolic requirements and thus avoids a mismatch in supply and demand and prevents metabolic stress. We discuss in detail key examples of EMS that our laboratories have discovered in the brain and the heart, and we outline potential further EMS mechanisms operating in tissues such as skeletal muscle, pancreas, and kidney. We suggest that the energy imbalance evoked by EMS uncoupling may be central to cellular dysfunction from which the hallmarks of aging and metabolic diseases emerge and may lead to generalized organ failure states-such as diverse flavors of heart failure and dementia. Understanding and manipulating EMS may be key to preventing or reversing these dysfunctions.
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Affiliation(s)
- Thomas A. Longden
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
- Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - W. Jonathan Lederer
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
- Laboratory of Molecular Cardiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA
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4
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Philip M, Snow RJ, Della Gatta PA, Callahan DL, Bellofiore N, Salamonsen LA, Palmer KR, Ellery SJ. Aspects of human uterine creatine metabolism during the menstrual cycle and at term pregnancy†. Biol Reprod 2023; 109:839-850. [PMID: 37602666 DOI: 10.1093/biolre/ioad099] [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: 06/11/2023] [Revised: 07/21/2023] [Accepted: 08/11/2023] [Indexed: 08/22/2023] Open
Abstract
Creatine metabolism likely contributes to energy homeostasis in the human uterus, but whether this organ synthesizes creatine and whether creatine metabolism is adjusted throughout the menstrual cycle and with pregnancy are largely unknown. This study determined endometrial protein expression of creatine-synthesizing enzymes arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT), creatine kinase (CKBB), and the creatine transporter (SLC6A8) throughout the menstrual cycle in fertile and primary infertile women. It also characterized creatine metabolism at term pregnancy, measuring aspects of creatine metabolism in myometrial and decidual tissue. In endometrial samples, AGAT, GAMT, SLC6A8, and CKBB were expressed in glandular and luminal epithelial cells. Except for SLC6A8, the other proteins were also located in stromal cells. Irrespective of fertility, AGAT, GAMT, and SLC6A8 high-intensity immunohistochemical staining was greatest in the early secretory phase of the menstrual cycle. During the proliferative phase, staining for SLC6A8 protein was greater (P = 0.01) in the primary infertile compared with the fertile group. Both layers of the term pregnant uterus contained creatine, phosphocreatine, guanidinoacetic acid, arginine, glycine, and methionine; detectable gene and protein expression of AGAT, GAMT, CKBB, and ubiquitous mitochondrial CK (uMt-CK); and gene expression of SLC6A8. The proteins AGAT, GAMT, CKBB, and SLC6A8 were uniformly distributed in the myometrium and localized to the decidual glands. In conclusion, endometrial tissue has the capacity to produce creatine and its capacity is highest around the time of fertilization and implantation. Both layers of the term pregnant uterus also contained all the enzymatic machinery and substrates of creatine metabolism.
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Affiliation(s)
- Mamatha Philip
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Rodney J Snow
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Paul A Della Gatta
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Damien L Callahan
- Centre for Molecular and Medical Research, School of Life and Environmental Sciences, Deakin University, Melbourne, VIC, Australia
| | - Nadia Bellofiore
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Lois A Salamonsen
- The Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Kirsten R Palmer
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Stacey J Ellery
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
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5
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Yu J, Im H, Lee G. Unwinding mechanism of SARS-CoV helicase (nsp13) in the presence of Ca 2+, elucidated by biochemical and single-molecular studies. Biochem Biophys Res Commun 2023; 668:35-41. [PMID: 37235917 PMCID: PMC10193821 DOI: 10.1016/j.bbrc.2023.05.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023]
Abstract
The recent outbreak of COVID-19 has created a serious health crisis with fatFal infectious viral diseases, such as Severe Acute Respiratory Syndrome (SARS). The nsp13, a helicase of coronaviruses is an essential element for viral replication that unwinds secondary structures of DNA and RNA, and is thus considered a major therapeutic target for treatment. The replication of coronaviruses and other retroviruses occurs in the cytoplasm of infected cells, in association with viral replication organelles, called virus-induced cytosolic double-membrane vesicles (DMVs). In addition, an increase in cytosolic Ca2+ concentration accelerates viral replication. However, the molecular mechanism of nsp13 in the presence of Ca2+ is not well understood. In this study, we applied biochemical methods and single-molecule techniques to demonstrate how nsp13 achieves its unwinding activity while performing ATP hydrolysis in the presence of Ca2+. Our study found that nsp13 could efficiently unwind double stranded (ds) DNA under physiological concentration of Ca2+ of cytosolic DMVs. These findings provide new insights into the properties of nsp13 in the range of calcium in cytosolic DMVs.
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Affiliation(s)
- Jeongmin Yu
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea
| | - Hyeryeon Im
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea
| | - Gwangrog Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea.
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6
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Jaciuk M, Scherf D, Kaszuba K, Gaik M, Rau A, Kościelniak A, Krutyhołowa R, Rawski M, Indyka P, Graziadei A, Chramiec-Głąbik A, Biela A, Dobosz D, Lin TY, Abbassi NEH, Hammermeister A, Rappsilber J, Kosinski J, Schaffrath R, Glatt S. Cryo-EM structure of the fully assembled Elongator complex. Nucleic Acids Res 2023; 51:2011-2032. [PMID: 36617428 PMCID: PMC10018365 DOI: 10.1093/nar/gkac1232] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/22/2022] [Accepted: 12/09/2022] [Indexed: 01/10/2023] Open
Abstract
Transfer RNA (tRNA) molecules are essential to decode messenger RNA codons during protein synthesis. All known tRNAs are heavily modified at multiple positions through post-transcriptional addition of chemical groups. Modifications in the tRNA anticodons are directly influencing ribosome decoding and dynamics during translation elongation and are crucial for maintaining proteome integrity. In eukaryotes, wobble uridines are modified by Elongator, a large and highly conserved macromolecular complex. Elongator consists of two subcomplexes, namely Elp123 containing the enzymatically active Elp3 subunit and the associated Elp456 hetero-hexamer. The structure of the fully assembled complex and the function of the Elp456 subcomplex have remained elusive. Here, we show the cryo-electron microscopy structure of yeast Elongator at an overall resolution of 4.3 Å. We validate the obtained structure by complementary mutational analyses in vitro and in vivo. In addition, we determined various structures of the murine Elongator complex, including the fully assembled mouse Elongator complex at 5.9 Å resolution. Our results confirm the structural conservation of Elongator and its intermediates among eukaryotes. Furthermore, we complement our analyses with the biochemical characterization of the assembled human Elongator. Our results provide the molecular basis for the assembly of Elongator and its tRNA modification activity in eukaryotes.
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Affiliation(s)
- Marcin Jaciuk
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - David Scherf
- Institute for Biology, Department for Microbiology, University of Kassel, Kassel 34132, Germany
| | - Karol Kaszuba
- European Molecular Biology Laboratory Hamburg, Hamburg 22607, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg 22607, Germany
| | - Monika Gaik
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Alexander Rau
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin 13355, Germany
| | - Anna Kościelniak
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Rościsław Krutyhołowa
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Michał Rawski
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Krakow 30-387, Poland
| | - Paulina Indyka
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Krakow 30-387, Poland
| | - Andrea Graziadei
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin 13355, Germany
| | | | - Anna Biela
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Dominika Dobosz
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Ting-Yu Lin
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
| | - Nour-el-Hana Abbassi
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
- Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw 02-091, Poland
| | - Alexander Hammermeister
- Malopolska Centre of Biotechnology (MCB), Jagiellonian University, Krakow 30-387, Poland
- Institute for Biology, Department for Microbiology, University of Kassel, Kassel 34132, Germany
| | - Juri Rappsilber
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin 13355, Germany
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Jan Kosinski
- European Molecular Biology Laboratory Hamburg, Hamburg 22607, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg 22607, Germany
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg 69117, Germany
| | - Raffael Schaffrath
- Institute for Biology, Department for Microbiology, University of Kassel, Kassel 34132, Germany
| | - Sebastian Glatt
- To whom correspondence should be addressed. Tel: +48 12 664 6321; Fax: +48 12 664 6902;
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7
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Abstract
Pericytes, attached to the surface of capillaries, play an important role in regulating local blood flow. Using optogenetic tools and genetically encoded reporters in conjunction with confocal and multiphoton imaging techniques, the 3D structure, anatomical organization, and physiology of pericytes have recently been the subject of detailed examination. This work has revealed novel functions of pericytes and morphological features such as tunneling nanotubes in brain and tunneling microtubes in heart. Here, we discuss the state of our current understanding of the roles of pericytes in blood flow control in brain and heart, where functions may differ due to the distinct spatiotemporal metabolic requirements of these tissues. We also outline the novel concept of electro-metabolic signaling, a universal mechanistic framework that links tissue metabolic state with blood flow regulation by pericytes and vascular smooth muscle cells, with capillary KATP and Kir2.1 channels as primary sensors. Finally, we present major unresolved questions and outline how they can be addressed.
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Affiliation(s)
- Thomas A Longden
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Guiling Zhao
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Molecular Cardiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ashwini Hariharan
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - W Jonathan Lederer
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Molecular Cardiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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8
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Wen B, Zheng Z, Wang L, Qian X, Wang X, Chen Y, Bao J, Jiang Y, Ji K, Liu H. HIF-1α is essential for the augmentation of myometrial contractility during labor†. Biol Reprod 2022; 107:1540-1550. [PMID: 36094838 PMCID: PMC9752684 DOI: 10.1093/biolre/ioac174] [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: 05/26/2022] [Revised: 07/29/2022] [Accepted: 09/09/2022] [Indexed: 12/24/2022] Open
Abstract
Uterine contraction is crucial for a successful labor and the prevention of postpartum hemorrhage. It is enhanced by hypoxia; however, its underlying mechanisms are yet to be elucidated. In this study, transcriptomes revealed that hypoxia-inducible factor-1alpha was upregulated in laboring myometrial biopsies, while blockade of hypoxia-inducible factor-1alpha decreased the contractility of the myometrium and myocytes in vitro via small interfering RNA and the inhibitor, 2-methoxyestradiol. Chromatin immunoprecipitation sequencing revealed that hypoxia-inducible factor-1alpha directly binds to the genome of contraction-associated proteins: the promoter of Gja1 and Ptgs2, and the intron of Oxtr. Silencing the hypoxia-inducible factor-1alpha reduced the expression of Ptgs2, Gja1, and Oxtr. Furthermore, blockade of Gja1 or Ptgs2 led to a significant decrease in myometrial contractions in the hypoxic tissue model, whereas atosiban did not remarkably influence contractility. Our study demonstrates that hypoxia-inducible factor-1alpha is essential for promoting myometrial contractility under hypoxia by directly targeting Gja1 and Ptgs2, but not Oxtr. These findings help us to better understand the regulation of myometrial contractions under hypoxia and provide a promising strategy for labor management and postpartum hemorrhage treatment.
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Affiliation(s)
| | | | - Lele Wang
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xueya Qian
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xiaodi Wang
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yunshan Chen
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Junjie Bao
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yanmin Jiang
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Kaiyuan Ji
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huishu Liu
- Correspondence: Guangzhou Key Laboratory of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, China. E-mail:
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9
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Chaker-Margot M, Werten S, Dunzendorfer-Matt T, Lechner S, Ruepp A, Scheffzek K, Maier T. Structural basis of activation of the tumor suppressor protein neurofibromin. Mol Cell 2022; 82:1288-1296.e5. [PMID: 35353986 DOI: 10.1016/j.molcel.2022.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/14/2022] [Accepted: 03/03/2022] [Indexed: 12/15/2022]
Abstract
Mutations in the NF1 gene cause the familial genetic disease neurofibromatosis type I, as well as predisposition to cancer. The NF1 gene product, neurofibromin, is a GTPase-activating protein and acts as a tumor suppressor by negatively regulating the small GTPase, Ras. However, structural insights into neurofibromin activation remain incompletely defined. Here, we provide cryoelectron microscopy (cryo-EM) structures that reveal an extended neurofibromin homodimer in two functional states: an auto-inhibited state with occluded Ras-binding site and an asymmetric open state with an exposed Ras-binding site. Mechanistically, the transition to the active conformation is stimulated by nucleotide binding, which releases a lock that tethers the catalytic domain to an extended helical repeat scaffold in the occluded state. Structure-guided mutational analysis supports functional relevance of allosteric control. Disease-causing mutations are mapped and primarily impact neurofibromin stability. Our findings suggest a role for nucleotides in neurofibromin regulation and may lead to therapeutic modulation of Ras signaling.
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Affiliation(s)
| | - Sebastiaan Werten
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria
| | | | - Stefan Lechner
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Angela Ruepp
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Klaus Scheffzek
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria.
| | - Timm Maier
- Biozentrum, University of Basel, 4056 Basel, Switzerland.
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10
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Wray S, Prendergast C, Arrowsmith S. Calcium-Activated Chloride Channels in Myometrial and Vascular Smooth Muscle. Front Physiol 2021; 12:751008. [PMID: 34867456 PMCID: PMC8637852 DOI: 10.3389/fphys.2021.751008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/24/2021] [Indexed: 11/24/2022] Open
Abstract
In smooth muscle tissues, calcium-activated chloride channels (CaCC) provide the major anionic channel. Opening of these channels leads to chloride efflux and depolarization of the myocyte membrane. In this way, activation of the channels by a rise of intracellular [Ca2+], from a variety of sources, produces increased excitability and can initiate action potentials and contraction or increased tone. We now have a good mechanistic understanding of how the channels are activated and regulated, due to identification of TMEM16A (ANO1) as the molecular entity of the channel, but key questions remain. In reviewing these channels and comparing two distinct smooth muscles, myometrial and vascular, we expose the differences that occur in their activation mechanisms, properties, and control. We find that the myometrium only expresses “classical,” Ca2+-activated, and voltage sensitive channels, whereas both tonic and phasic blood vessels express classical, and non-classical, cGMP-regulated CaCC, which are voltage insensitive. This translates to more complex activation and regulation in vascular smooth muscles, irrespective of whether they are tonic or phasic. We therefore tentatively conclude that although these channels are expressed and functionally important in all smooth muscles, they are probably not part of the mechanisms governing phasic activity. Recent knockdown studies have produced unexpected functional results, e.g. no effects on labour and delivery, and tone increasing in some but decreasing in other vascular beds, strongly suggesting that there is still much to be explored concerning CaCC in smooth muscle.
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Affiliation(s)
- Susan Wray
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Clodagh Prendergast
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Sarah Arrowsmith
- Department of Life Sciences, Manchester Metropolitan University, Manchester, United Kingdom
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11
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Chen L, Wang L, Luo Y, Huang Q, Ji K, Bao J, Liu H. Integrated Proteotranscriptomics of Human Myometrium in Labor Landscape Reveals the Increased Molecular Associated With Inflammation Under Hypoxia Stress. Front Immunol 2021; 12:722816. [PMID: 34671346 PMCID: PMC8521035 DOI: 10.3389/fimmu.2021.722816] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 09/01/2021] [Indexed: 01/16/2023] Open
Abstract
During labor, a variety of coordinated physiological and biochemical events cause the myometrium to transition from a quiescent to contractile state; the molecular mechanisms responsible for this transition, however, remain unclear. To better understand this transition at a molecular level, the global transcriptome and proteome of human myometrial samples in labor and those not in labor were investigated through RNA sequencing (RNA-seq) and quantitative liquid chromatography–tandem mass spectrometry (LC-MS/MS) via data-independent acquisition (DIA) and parallel reaction monitoring (PRM) methods. Furthermore, an integrated proteotranscriptomic analysis was performed to explore biological processes and pathway alterations during labor; this analysis identified 1,626 differentially expressed mRNAs (1,101 upregulated, 525 downregulated) and 135 differentially expressed proteins (97 upregulated, 38 downregulated) in myometrium between nonlabor and in labor groups. The comprehensive results of these analyses showed that the upregulated mRNAs and proteins increased inflammation under hypoxia stress in the myometrium under labor, and related proteins and cytokines were validated by PRM and Luminex assays. Our study confirmed the biological process of inflammation and hypoxia in laboring myometrium at the transcriptome and proteome levels and provided recourse to discover new molecular and biological changes during labor.
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Affiliation(s)
- Lina Chen
- School of Medicine, South China University of Technology, Guangzhou, China.,Guangzhou Key Laboratory of Maternal-Fetal Medicine, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Lele Wang
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yihong Luo
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Qian Huang
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Kaiyuan Ji
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Junjie Bao
- Guangzhou Key Laboratory of Maternal-Fetal Medicine, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huishu Liu
- School of Medicine, South China University of Technology, Guangzhou, China.,Guangzhou Key Laboratory of Maternal-Fetal Medicine, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
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12
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Liu NN, Song ZY, Guo HL, Yin H, Chen WF, Dai YX, Xin BG, Ai X, Ji L, Wang QM, Hou XM, Dou SX, Rety S, Xi XG. Endogenous Bos taurus RECQL is predominantly monomeric and more active than oligomers. Cell Rep 2021; 36:109688. [PMID: 34496242 DOI: 10.1016/j.celrep.2021.109688] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 07/11/2021] [Accepted: 08/19/2021] [Indexed: 02/07/2023] Open
Abstract
There is broad consensus that RecQ family helicase is a high-order oligomer that dissociates into a dimer upon ATP binding. This conclusion is based mainly on studies of highly purified recombinant proteins, and the oligomeric states of RecQ helicases in living cells remain unknown. We show here that, in contrast to current models, monomeric RECQL helicase is more abundant than oligomer/dimer forms in living cells. Further characterization of endogenous BtRECQL and isolated monomeric BtRECQL using various approaches demonstrates that both endogenous and recombinant monomeric BtRECQL effectively function as monomers, displaying higher helicase and ATPase activities than dimers and oligomers. Furthermore, monomeric BtRECQL unfolds intramolecular G-quadruplex DNA as efficiently as human RECQL and BLM helicases. These discoveries have implications for understanding endogenous RECQL oligomeric structures and their regulation. It is worth revisiting oligomeric states of the other members of the RecQ family helicases in living cells.
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Affiliation(s)
- Na-Nv Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Ze-Yu Song
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Hai-Lei Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Hu Yin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wei-Fei Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yang-Xue Dai
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Ben-Ge Xin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xia Ai
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Lei Ji
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Qing-Man Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xi-Miao Hou
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Shuo-Xing Dou
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Stephane Rety
- Univ. Lyon, ENS de Lyon, Univ. Claude Bernard, CNRS UMR 5239, INSERM U1210, LBMC, 46 allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Xu-Guang Xi
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; LBPA, Ecole Normale Supérieure Paris-Saclay, CNRS, Université Paris Saclay, Gif-sur-Yvette, France.
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13
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Tao L, Zhang H, Wang H, Li L, Huang L, Su F, Yuan X, Luo M, Ge L. Characteristics of lipid droplets and the expression of proteins involved in lipolysis in the murine cervix during mid-pregnancy. Reprod Fertil Dev 2021; 32:967-975. [PMID: 32693909 DOI: 10.1071/rd19425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 05/30/2020] [Indexed: 12/16/2022] Open
Abstract
Lipid droplets (LDs) are reservoirs of arachidonoyl lipids for prostaglandin (PG) E2 synthesis, and progesterone can stimulate PGE2 synthesis; however, the relationship between progesterone and LD metabolism in the murine cervix remains unclear. In the present study we examined LD distribution and changes in the expression of proteins involved in lipolysis and autophagy in the murine cervix during pregnancy, and compared the findings with those in dioestrous mice. During mid-pregnancy, LDs were predominantly distributed in the cervical epithelium. Electron microscopy revealed the transfer of numerous LDs from the basal to apical region in the luminal epithelium, marked catabolism of LDs, an elevated number of LDs and autophagosomes and a higher LD:mitochondrion size ratio in murine cervical epithelial cells (P<0.05). In addition, immunohistochemical and western blotting analyses showed significantly higher cAMP-dependent protein kinase, adipose triglyceride lipase and hormone-sensitive lipase expression, and a higher light chain 3 (LC3) II:LC3I ratio in the stroma and smooth muscles and, particularly, in murine cervical epithelial cells, during mid-pregnancy than late dioestrus. In conclusion, these results suggest that the enhanced lipolysis of LDs and autophagy in murine cervical tissues were closely related to pregnancy and were possibly controlled by progesterone because LD catabolism may be necessary for energy provision and PGE2 synthesis to maintain a closed pregnant cervix.
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Affiliation(s)
- Longlong Tao
- College of Animal Science and Technology, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China
| | - Hongyan Zhang
- College of Animal Science and Technology, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China
| | - Hongmei Wang
- College of Animal Science and Technology, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China
| | - Liuhui Li
- College of Animal Science and Technology, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China
| | - Libo Huang
- College of Animal Science and Technology, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China
| | - Feng Su
- College of Animal Science and Technology, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China
| | - Xuejun Yuan
- College of Life Science, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China
| | - Mingjiu Luo
- College of Animal Science and Technology, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China; and Corresponding author. ;
| | - Lijiang Ge
- College of Animal Science and Technology, Shandong Agricultural University, N0.61, Daizong Street, Taian, Shandong Province, 271018, P.R. China; and Corresponding author. ;
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14
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Kim S, Yoon I, Son J, Park J, Kim K, Lee JH, Park SY, Kang BS, Han JM, Hwang KY, Kim S. Leucine-sensing mechanism of leucyl-tRNA synthetase 1 for mTORC1 activation. Cell Rep 2021; 35:109031. [PMID: 33910001 DOI: 10.1016/j.celrep.2021.109031] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 12/18/2020] [Accepted: 04/02/2021] [Indexed: 01/07/2023] Open
Abstract
Leucyl-tRNA synthetase 1 (LARS1) mediates activation of leucine-dependent mechanistic target of rapamycin complex 1 (mTORC1) as well as ligation of leucine to its cognate tRNAs, yet its mechanism of leucine sensing is poorly understood. Here we describe leucine binding-induced conformational changes of LARS1. We determine different crystal structures of LARS1 complexed with leucine, ATP, and a reaction intermediate analog, leucyl-sulfamoyl-adenylate (Leu-AMS), and find two distinct functional states of LARS1 for mTORC1 activation. Upon leucine binding to the synthetic site, H251 and R517 in the connective polypeptide and 50FPYPY54 in the catalytic domain change the hydrogen bond network, leading to conformational change in the C-terminal domain, correlating with RagD association. Leucine binding to LARS1 is increased in the presence of ATP, further augmenting leucine-dependent interaction of LARS1 and RagD. Thus, this work unveils the structural basis for leucine-dependent long-range communication between the catalytic and RagD-binding domains of LARS1 for mTORC1 activation.
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Affiliation(s)
- Sulhee Kim
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Ina Yoon
- Medicinal Bioconvergence Research Center, Institute for Artificial Intelligence and Biomedical Research, College of Pharmacy & College of Medicine, Gangnam Severance Hospital, Yonsei University, Incheon 21983, Republic of Korea
| | - Jonghyeon Son
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Junga Park
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Kibum Kim
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Republic of Korea; Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Republic of Korea
| | - Ji-Ho Lee
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Sam-Yong Park
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Beom Sik Kang
- School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jung Min Han
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Republic of Korea; Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Republic of Korea
| | - Kwang Yeon Hwang
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea.
| | - Sunghoon Kim
- Medicinal Bioconvergence Research Center, Institute for Artificial Intelligence and Biomedical Research, College of Pharmacy & College of Medicine, Gangnam Severance Hospital, Yonsei University, Incheon 21983, Republic of Korea.
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15
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Wang L, Hu H, Morse AN, Han X, Bao J, Yang J, Chen Y, Liu H. Activation of Autophagy in Human Uterine Myometrium During Labor. Reprod Sci 2020; 27:1665-1672. [PMID: 32430716 DOI: 10.1007/s43032-020-00198-3] [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] [Indexed: 01/21/2023]
Abstract
OBJECTIVE The purpose of this study was to analyze the autophagy of the human uterine myometrium during the labor. METHODS We collected uterine myometrium strips from term, singleton, nulliparous healthy women undergoing cesarean delivery before labor (nonlabor group, n = 10) or during normal labor (in-labor group, n = 10) without rupturing of membrane. The indications for cesarean delivery were breech presentation or maternal request. Transmission electron microscopy was used to observe autophagosomes. Reverse transcriptase polymerase chain reaction, immunofluorescence, and Western blot were used to quantify the messenger RNA (mRNA) and protein level of the autophagy markers LC3B, P62, and Beclin-1 in the uterine muscle strips. RESULTS There were no differences between both groups in maternal age, body mass index, gestational week, neonatal weight, operative bleeding, and postpartum bleeding. Transmission electron micrographs showed that autophagosomes existed in myometrial tissue in both groups. There were more autophagosomes in the in-labor group than in the nonlabor group, and the difference had significance. The in-labor group had significantly greater LC3B mRNA expression but significantly lower P62 mRNA expression compared with the nonlabor group. Semiquantitative immunofluorescence in uterine myometrial cells in the in-labor group showed increased LC3B puncta formation and greater Beclin-1 expression but reduced P62 puncta formation compared with the nonlabor group. The ratio of LC3BII/I proteins was significantly higher, but P62 protein was significantly lower in the in-labor group compared with the nonlabor group. The Beclin-1 mRNA and protein expressions were not significantly different between the 2 groups. CONCLUSION Autophagy was activated in human uterine myometrium during labor and might play an important role in maintaining uterine contraction function.
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Affiliation(s)
- Lele Wang
- Department of Obstetrics, First Affiliated Hospital of Jinan University, Guangzhou, China.,Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, China
| | - Huiping Hu
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, China
| | - Abraham Nick Morse
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, China
| | - Xinjia Han
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, China
| | - Junjie Bao
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, China
| | - Jingying Yang
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, China
| | - Yunshan Chen
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, China
| | - Huishu Liu
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, China.
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16
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Wray S, Arrowsmith S. Uterine Excitability and Ion Channels and Their Changes with Gestation and Hormonal Environment. Annu Rev Physiol 2020; 83:331-357. [PMID: 33158376 DOI: 10.1146/annurev-physiol-032420-035509] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We address advances in the understanding of myometrial physiology, focusing on excitation and the effects of gestation on ion channels and their relevance to labor. This review moves through pioneering studies to exciting new findings. We begin with the myometrium and its myocytes and describe how excitation might initiate and spread in this myogenic smooth muscle. We then review each of the ion channels in the myometrium: L- and T-type Ca2+ channels, KATP (Kir6) channels, voltage-dependent K channels (Kv4, Kv7, and Kv11), twin-pore domain K channels (TASK, TREK), inward rectifier Kir7.1, Ca2+-activated K+ channels with large (KCNMA1, Slo1), small (KCNN1-3), and intermediate (KCNN4) conductance, Na-activated K channels (Slo2), voltage-gated (SCN) Na+ and Na+ leak channels, nonselective (NALCN) channels, the Na K-ATPase, and hyperpolarization-activated cation channels. We finish by assessing how three key hormones- oxytocin, estrogen, and progesterone-modulate and integrate excitability throughout gestation.
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Affiliation(s)
- Susan Wray
- Department of Women's and Children's Health, University of Liverpool, Liverpool L69 3BX, United Kingdom;
| | - Sarah Arrowsmith
- Department of Women's and Children's Health, University of Liverpool, Liverpool L69 3BX, United Kingdom;
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17
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Prendergast C, Wray S. Human myometrial artery function and endothelial cell calcium signalling are reduced by obesity: Can this contribute to poor labour outcomes? Acta Physiol (Oxf) 2019; 227:e13341. [PMID: 31299139 DOI: 10.1111/apha.13341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 06/17/2019] [Accepted: 07/07/2019] [Indexed: 12/15/2022]
Abstract
AIMS Determining how obesity affects function in human myometrial arteries, to help understand why childbirth has poor outcomes in obese women. METHODS Myometrial arteries were studied from 84 biopsies. Contraction (vasopressin and U-46619) and relaxation (carbachol, bradykinin, SNAP) was assessed using wire myography. eNOS activity was assessed using L-NAME. Cholesterol was reduced using methyl-β-cyclodextrin to determine whether it altered responses. Differences in endothelial cell intracellular Ca2+ signalling were assessed using confocal microscopy. RESULTS The effects of BMI on relaxation were agonist specific and very marked; all vessels, irrespective of BMI, relaxed to bradykinin but 0% of vessels (0/13) from obese women relaxed to carbachol, compared to 59% (10/17) from normal weight women. Cholesterol-lowering drugs did not restore carbachol responses (n = 6). All vessels, irrespective of BMI, relaxed when NO was directly released by SNAP (n = 19). Inhibition of eNOS with L-NAME had a significant effect in normal but not overweight/obese vessels. Compared to bradykinin, a lower proportion of endothelial cells responded to carbachol and the amplitude of the calcium response was significantly less, in all vessels. Furthermore, a significantly lower proportion of endothelial cells responded to carbachol in the overweight/obese group compared to control. In contrast to relaxation, the effect of contractile agonists was unchanged with increasing BMI. CONCLUSIONS The ability of human myometrial arteries to relax is significantly impaired with obesity, and our data suggest this is due to a deficit in endothelial calcium signalling. This inability to recover following compression during contractions, might contribute to poor labours in obese women.
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Affiliation(s)
- Clodagh Prendergast
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine University of Liverpool Liverpool UK
| | - Susan Wray
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine University of Liverpool Liverpool UK
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18
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Wang L, Hu H, Morse AN, Han X, Bao J, Yang J, Chen Y, Liu H. Activation of Autophagy in Human Uterine Myometrium During Labor. Reprod Sci 2019:1933719119834351. [PMID: 30845895 DOI: 10.1177/1933719119834351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE: The purpose of this study was to analyze the autophagy of the human uterine myometrium during the labor. METHODS: We collected uterine myometrium strips from term, singleton, nulliparous healthy women undergoing cesarean delivery before labor (nonlabor group, n = 10) or during normal labor (in-labor group, n = 10) without rupturing of membrane. The indications for cesarean delivery were breech presentation or maternal request. Transmission electron microscopy was used to observe autophagosomes. Reverse transcriptase polymerase chain reaction, immunofluorescence, and Western blot were used to quantify the messenger RNA (mRNA) and protein level of the autophagy markers LC3B, P62, and Beclin-1 in the uterine muscle strips. RESULTS: There were no differences between both groups in maternal age, body mass index, gestational week, neonatal weight, operative bleeding, and postpartum bleeding. Transmission electron micrographs showed that autophagosomes existed in myometrial tissue in both groups. There were more autophagosomes in the in-labor group than in the nonlabor group, and the difference had significance. The in-labor group had significantly greater LC3B mRNA expression but significantly lower P62 mRNA expression compared with the nonlabor group. Semiquantitative immunofluorescence in uterine myometrial cells in the in-labor group showed increased LC3B puncta formation and greater Beclin-1 expression but reduced P62 puncta formation compared with the nonlabor group. The ratio of LC3BII/I proteins was significantly higher, but P62 protein was significantly lower in the in-labor group compared with the nonlabor group. The Beclin-1 mRNA and protein expressions were not significantly different between the 2 groups. CONCLUSION: Autophagy was activated in human uterine myometrium during labor and might play an important role in maintaining uterine contraction function.
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Affiliation(s)
- Lele Wang
- 1 Department of Obstetrics, First Affiliated Hospital of Jinan University, Guangzhou, China
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huiping Hu
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Abraham Nick Morse
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xinjia Han
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Junjie Bao
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jingying Yang
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yunshan Chen
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huishu Liu
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
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19
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The Myometrium: From Excitation to Contractions and Labour. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1124:233-263. [PMID: 31183830 DOI: 10.1007/978-981-13-5895-1_10] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
We start by describing the functions of the uterus, its structure, both gross and fine, innervation and blood supply. It is interesting to note the diversity of the female's reproductive tract between species and to remember it when working with different animal models. Myocytes are the overwhelming cell type of the uterus (>95%) and our focus. Their function is to contract, and they have an intrinsic pacemaker and rhythmicity, which is modified by hormones, stretch, paracrine factors and the extracellular environment. We discuss evidence or not for pacemaker cells in the uterus. We also describe the sarcoplasmic reticulum (SR) in some detail, as it is relevant to calcium signalling and excitability. Ion channels, including store-operated ones, their contributions to excitability and action potentials, are covered. The main pathway to excitation is from depolarisation opening voltage-gated Ca2+ channels. Much of what happens downstream of excitability is common to other smooth muscles, with force depending upon the balance of myosin light kinase and phosphatase. Mechanisms of maintaining Ca2+ balance within the myocytes are discussed. Metabolism, and how it is intertwined with activity, blood flow and pH, is covered. Growth of the myometrium and changes in contractile proteins with pregnancy and parturition are also detailed. We finish with a description of uterine activity and why it is important, covering progression to labour as well as preterm and dysfunctional labours. We conclude by highlighting progress made and where further efforts are required.
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Li X, Qian X, Jiang H, Xia Y, Zheng Y, Li J, Huang BJ, Fang J, Qian CN, Jiang T, Zeng YX, Lu Z. Nuclear PGK1 Alleviates ADP-Dependent Inhibition of CDC7 to Promote DNA Replication. Mol Cell 2018; 72:650-660.e8. [PMID: 30392930 DOI: 10.1016/j.molcel.2018.09.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 07/30/2018] [Accepted: 09/06/2018] [Indexed: 01/11/2023]
Abstract
DNA replication is initiated by assembly of the kinase cell division cycle 7 (CDC7) with its regulatory activation subunit, activator of S-phase kinase (ASK), to activate DNA helicase. However, the mechanism underlying regulation of CDC7-ASK complex is unclear. Here, we show that ADP generated from CDC7-mediated MCM phosphorylation binds to an allosteric region of CDC7, disrupts CDC7-ASK interaction, and inhibits CDC7-ASK activity in a feedback way. EGFR- and ERK-activated casein kinase 2α (CK2α) phosphorylates nuclear phosphoglycerate kinase (PGK) 1 at S256, resulting in interaction of PGK1 with CDC7. CDC7-bound PGK1 converts ADP to ATP, thereby abrogating the inhibitory effect of ADP on CDC7-ASK activity, promoting the recruitment of DNA helicase to replication origins, DNA replication, cell proliferation, and brain tumorigenesis. These findings reveal an instrumental self-regulatory mechanism of CDC7-ASK activity by its kinase reaction product ADP and a nonglycolytic role for PGK1 in abrogating this negative feedback in promoting tumor development.
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Affiliation(s)
- Xinjian Li
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xu Qian
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Hongfei Jiang
- Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs of Minister of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yan Xia
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Yanhua Zheng
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jing Li
- Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs of Minister of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Bi-Jun Huang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Jing Fang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266061, China; Qingdao Cancer Institute, Qingdao, Shandong 266061, China
| | - Chao-Nan Qian
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Tao Jiang
- Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Marine Drugs of Minister of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Yi-Xin Zeng
- CAS Key Laboratory of Infection and Immunity, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Zhimin Lu
- Brain Tumor Center, Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Cancer Biology Program, MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, The University of TX, Houston, Texas 77030, USA.
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Ghesquière L, Hanssens S, Leroy A, Petit C, Deruelle P, Azaïs H. [Sport: A key element for myometrial contractility and regulation of adipokines in obese pregnant women?]. ACTA ACUST UNITED AC 2018; 46:587-592. [PMID: 29937109 DOI: 10.1016/j.gofs.2018.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Indexed: 01/09/2023]
Abstract
Obesity is a major public health problem. Pregnant women are also affected by this epidemic. In pregnant women, obesity increases obstetric and neonatal complications, and is associated with alterations in the quality of labor that could be explained by reduced myometrial contractility. This leads to an increase in the rate of caesarean sections and postpartum haemorrhages in this population at risk. Adipokines, hormones secreted by adipose tissue, may have a role in altering the myometrial contractility. Weight loss in these patients is based on dietary management and on physical activity, which could be a way to improve adipokines action and uterine contractility. The objective of this literature review was to review current knowledge about the role of adipokines on uterine contractility in obese pregnant women and to assess the interest of sport in improving contractility and in reducing obstetric complications in these women.
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Affiliation(s)
- L Ghesquière
- Département d'obstétrique, hôpital Jeanne-de-Flandre, CHU de Lille, 59000 Lille, France.
| | - S Hanssens
- Département d'obstétrique, hôpital Jeanne-de-Flandre, CHU de Lille, 59000 Lille, France
| | - A Leroy
- Département d'obstétrique, hôpital Jeanne-de-Flandre, CHU de Lille, 59000 Lille, France
| | - C Petit
- Département d'obstétrique, hôpital Jeanne-de-Flandre, CHU de Lille, 59000 Lille, France
| | - P Deruelle
- Département d'obstétrique, hôpital Jeanne-de-Flandre, CHU de Lille, 59000 Lille, France; EA4489-Environnement périnatal et croissance, université de Lille, 59000 Lille, France
| | - H Azaïs
- Département d'obstétrique, hôpital Jeanne-de-Flandre, CHU de Lille, 59000 Lille, France
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Hellman KM, Kuhn CS, Tu FF, Dillane KE, Shlobin NA, Senapati S, Zhou X, Li W, Prasad PV. Cine MRI during spontaneous cramps in women with menstrual pain. Am J Obstet Gynecol 2018; 218:506.e1-506.e8. [PMID: 29409786 DOI: 10.1016/j.ajog.2018.01.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/16/2018] [Accepted: 01/23/2018] [Indexed: 10/18/2022]
Abstract
BACKGROUND The lack of noninvasive methods to study dysmenorrhea has resulted in poor understanding of the mechanisms underlying pain, insufficient diagnostic tests, and limited treatment options. To address this knowledge gap, we have developed a magnetic resonance imaging-based strategy for continuously monitoring the uterus in relationship to participants' spontaneous pain perception. OBJECTIVE The study objective was to evaluate whether magnetic resonance imaging can detect real-time changes in myometrial activity during cramping episodes in women with dysmenorrhea, with a handheld squeeze bulb for pain reporting. STUDY DESIGN Sixteen women with dysmenorrhea and 10 healthy control women both on and off their menses were evaluated with magnetic resonance imaging while not taking analgesic medication. Continuous magnetic resonance imaging was acquired using half-Fourier acquisition single-shot turbo spin echo sequence along with simultaneous reporting of pain severity with a squeeze bulb. Pearson's coefficient was used to compare results between reviewers. Proportional differences between women with dysmenorrhea and controls on/off menses were evaluated with a Fisher exact test. The temporal relationships between signal changes were evaluated with Monte Carlo simulations. RESULTS Spontaneous progressive decreases in myometrial signal intensity were more frequently observed in women on their menses than in the absence of pain in the same women off their menses or participants without dysmenorrhea (P < .01). Women without reductions in myometrial signal intensity on their menses either had a history of endometriosis or were not in pain. Observations of myometrial events were consistently reported between 2 raters blinded to menstrual pain or day status (r = 0.97, P < .001). Episodes of cramping occurred either immediately before or 32-70 seconds after myometrial signal change onset (P < .05). CONCLUSION Transient decreases in myometrial uterine T2-weighted signal intensity can be reliably measured in women with menstrual pain. The directionality of signal change and temporal relationship to pain onset suggest that cramping pain may be caused by a combination of uterine pressure and hemodynamic dysfunction.
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Almohanna AM, Wray S. Hypoxic conditioning in blood vessels and smooth muscle tissues: effects on function, mechanisms, and unknowns. Am J Physiol Heart Circ Physiol 2018; 315:H756-H770. [PMID: 29702009 DOI: 10.1152/ajpheart.00725.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hypoxic preconditioning, the protective effect of brief, intermittent hypoxic or ischemic episodes on subsequent more severe hypoxic episodes, has been known for 30 yr from studies on cardiac muscle. The concept of hypoxic preconditioning has expanded; excitingly, organs beyond the heart, including the brain, liver, and kidney, also benefit. Preconditioning of vascular and visceral smooth muscles has received less attention despite their obvious importance to health. In addition, there has been no attempt to synthesize the literature in this field. Therefore, in addition to overviewing the current understanding of hypoxic conditioning, in the present review, we consider the role of blood vessels in conditioning and explore evidence for conditioning in other smooth muscles. Where possible, we have distinguished effects on myocytes from other cell types in the visceral organs. We found evidence of a pivotal role for blood vessels in conditioning and for conditioning in other smooth muscle, including the bladder, vascular myocytes, and gastrointestinal tract, and a novel response in the uterus of a hypoxic-induced force increase, which helps maintain contractions during labor. To date, however, there are insufficient data to provide a comprehensive or unifying mechanism for smooth muscles or visceral organs and the effects of conditioning on their function. This also means that no firm conclusions can be drawn as to how differences between smooth muscles in metabolic and contractile activity may contribute to conditioning. Therefore, we have suggested what may be general mechanisms of conditioning occurring in all smooth muscles and tabulated tissue-specific mechanistic findings and suggested ideas for further progress.
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Affiliation(s)
- Asmaa M Almohanna
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine University of Liverpool , Liverpool , United Kingdom.,Princess Nourah bint Abdulrahman University , Riyadh , Saudi Arabia
| | - Susan Wray
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine University of Liverpool , Liverpool , United Kingdom
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Edwards Y. An Msh3 ATPase domain mutation has no effect on MMR function. BMC Res Notes 2017; 10:616. [PMID: 29178930 PMCID: PMC5702223 DOI: 10.1186/s13104-017-2939-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 11/15/2017] [Indexed: 11/10/2022] Open
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Wiberg-Itzel E, Wray S, Åkerud H. A randomized controlled trial of a new treatment for labor dystocia. J Matern Fetal Neonatal Med 2017; 31:2237-2244. [PMID: 28587493 DOI: 10.1080/14767058.2017.1339268] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Labor dystocia is an intransigent, high-profile issue in obstetric care. Amniotic fluid lactate (AFL) reflects the uterine metabolic status. High levels associate with subsequent need for operative intervention due to dystocia. In sports medicine, it is known that lactic acid can affect muscular performance and can be decreased by bicarbonate given orally before physical activity. MATERIAL AND METHODS Two hundred dystocic deliveries were included. At the confirmation of dystocia, the AFL-level was analyzed. Deliveries were randomized to an intake of bicarbonate or not. In the "non-bicarbonate-group", stimulation with oxytocin was started immediately. In the "bicarbonate-group", bicarbonate was given; and oxytocin was started 1 hour after the intake. New sampling of AF was performed after 1 hour in both groups. OUTCOME MEASURED if an oral intake of bicarbonate changes the AFL levels and enhances delivery outcome in dystocic deliveries. RESULTS Bicarbonate decreases the AFL levels (p < .001). The spontaneous vaginal delivery rate after treatment with bicarbonate was increased (p = .007), without affecting the fetal outcome. CONCLUSIONS An increase of spontaneous vaginal deliveries resulted from bicarbonate ingestion by dystocic women. A decreased level of AFL-level was shown. This simple, low cost treatment has the potential to improve maternal morbidity and satisfaction worldwide.
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Affiliation(s)
- Eva Wiberg-Itzel
- a Department of Obstetrics and Gynecology , Sodersjukhuset , Stockholm , Sweden.,b Department of Clinical Science and Education, Section of Obstetrics and Gynaecology , Karolinska Institutet , Sodersjukhuset , Sweden
| | - Susan Wray
- c Department of Molecular and Cellular Physiology , Institute of Translational Medicine, University of Liverpool , Liverpool , UK
| | - Helena Åkerud
- d Department of Immunology, Genetics and Pathology , Uppsala University , Uppsala , Sweden
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Hellman KM, Yu PY, Oladosu FA, Segel C, Han A, Prasad PV, Jilling T, Tu FF. The Effects of Platelet-Activating Factor on Uterine Contractility, Perfusion, Hypoxia, and Pain in Mice. Reprod Sci 2017. [PMID: 28631554 DOI: 10.1177/1933719117715122] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
It is widely hypothesized that menstrual pain is triggered by prostaglandin synthesis that evokes high-pressure uterine contractions and ischemia. However, the effects of molecules implicated in menstrual pain on uterine contractility, perfusion, and oxygenation in vivo have been rarely demonstrated. Studies in women that do not respond to nonsteroidal anti-inflammatory drugs (NSAIDs) have reported elevated levels of platelet-activating factor (PAF). To establish in vivo evidence of PAF's capability to impair uterine homeostasis and to elicit visceral pain, we examined the effects of the PAF receptor agonist (carbamyl PAF [CPAF]) in comparison to other molecules hypothesized to play a role in uterine pain in mice. Uterine pressure was increased by oxytocin, prostaglandin F2α (PGF2α), and CPAF. Even in the absence of inflammatory molecules, uterine contractions reduced uterine oxygenation by 38%. CPAF reduced uterine perfusion by 40% ± 8% and elicited further oxygen desaturation approaching hypoxia (9.4 ± 3.4 mm Hg Pao2). Intraperitoneal injections of CPAF and PGF2α evoked visceral pain and pelvic hyperalgesia in awake wild-type mice. However, pain was not observed in identically injected PAF-receptor knockout mice. Thus, our model provides a demonstration that a molecule implicated in NSAID-resistant dysmenorrhea has a detrimental effect on uterine homeostasis and is capable of causing visceral pain. Our results support the general hypothesis that menstrual cramps are caused by uterine contractions, impaired perfusion, and reduced oxygenation. Since this study was limited to mice, confirmation of these results in humans would be valuable for development of novel therapeutics targeted at inflammatory precursors, contractility, perfusion, and tissue oxygenation.
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Affiliation(s)
- Kevin M Hellman
- 1 Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Evanston, IL, USA
- 2 Deptartment of Obstetrics and Gynecology, University of Chicago Pritzker School of Medicine, Chicago, IL, USA
| | - Peter Y Yu
- 1 Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Evanston, IL, USA
| | - Folabomi A Oladosu
- 1 Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Evanston, IL, USA
- 2 Deptartment of Obstetrics and Gynecology, University of Chicago Pritzker School of Medicine, Chicago, IL, USA
| | - Chaya Segel
- 1 Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Evanston, IL, USA
| | - Alice Han
- 1 Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Evanston, IL, USA
| | - Pottumarthi V Prasad
- 3 Department of Radiology, NorthShore University HealthSystem, Evanston, IL, USA
| | - Tamas Jilling
- 4 Department of Pediatrics, NorthShore University HealthSystem, Evanston, IL, USA
| | - Frank F Tu
- 1 Department of Obstetrics and Gynecology, NorthShore University HealthSystem, Evanston, IL, USA
- 2 Deptartment of Obstetrics and Gynecology, University of Chicago Pritzker School of Medicine, Chicago, IL, USA
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Functional involvement of protein kinase C, Rho-kinase and TRPC3 decreases while PLC increases with advancement of pregnancy in mediating oxytocin-induced myometrial contractions in water buffaloes ( Bubalus bubalis ). Theriogenology 2017; 92:176-189. [DOI: 10.1016/j.theriogenology.2016.12.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 12/06/2016] [Accepted: 12/06/2016] [Indexed: 11/20/2022]
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Effects of adipokines and obesity on uterine contractility. Cytokine Growth Factor Rev 2017; 34:59-66. [DOI: 10.1016/j.cytogfr.2017.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/23/2016] [Accepted: 01/09/2017] [Indexed: 01/09/2023]
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Menshanov PN, Bannova AV, Dygalo NN. Anoxia ameliorates the dexamethasone-induced neurobehavioral alterations in the neonatal male rat pups. Horm Behav 2017; 87:122-128. [PMID: 27865789 DOI: 10.1016/j.yhbeh.2016.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 01/03/2023]
Abstract
Glucocorticoids and hypoxia are two essential factors affecting the brain development during labor and delivery. In addition to the neurobehavioral alterations induced separately by these factors, glucocorticoids can attenuate the deleterious consequences of severe hypoxia-ischemia on the brain development, acting as a neuroprotective agent in combination with hypoxia. The role of hypoxia in the combined action with corticosteroids is less clear. Severe hypoxia-ischemia results in the massive activation of caspase-3, masking any other effects of hypoxia on the neonatal brain exposed to glucocorticoids. As a result, the effects of mild hypoxia on the developing brain pretreated with glucocorticoids remain unclear. To analyze this problem, 2-day-old male rats were treated with dexamethasone (DEX) before the subsequent exposure to mild 10-min anoxia or normoxia. The treatment with only DEX resulted in the delay in the development of the negative geotaxis reaction and in the decrease in locomotor activity of the neonatal male pups. The mild anoxic event attenuated these DEX-induced neurobehavioral alterations. The treatment with DEX, but not the mild anoxic exposure alone, resulted in the delayed upregulation of active caspase-3 in the prefrontal cortex and in the brainstem of the male pups. This glucocorticoid-induced upregulation of active caspase-3 was prevented by the anoxic event. The present findings evidence that mild anoxia is capable of ameliorating the glucocorticoid-induced neurodevelopmental alterations in the neonatal rats if the artificial or the naturally occurring increase in the levels of glucocorticoids occurred just before the episode of hypoxia.
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Affiliation(s)
- Petr N Menshanov
- Functional Neurogenomics Laboratory, Institute of Cytology and Genetics, Russian Academy of Science, Novosibirsk, Russian Federation; Department of Natural Sciences, Novosibirsk State University, Novosibirsk, Russian Federation.
| | - Anita V Bannova
- Functional Neurogenomics Laboratory, Institute of Cytology and Genetics, Russian Academy of Science, Novosibirsk, Russian Federation
| | - Nikolay N Dygalo
- Functional Neurogenomics Laboratory, Institute of Cytology and Genetics, Russian Academy of Science, Novosibirsk, Russian Federation; Department of Natural Sciences, Novosibirsk State University, Novosibirsk, Russian Federation
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Nijemeisland M, Abdelmohsen LKEA, Huck WTS, Wilson DA, van Hest JCM. A Compartmentalized Out-of-Equilibrium Enzymatic Reaction Network for Sustained Autonomous Movement. ACS CENTRAL SCIENCE 2016; 2:843-849. [PMID: 27924313 PMCID: PMC5126709 DOI: 10.1021/acscentsci.6b00254] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Indexed: 05/04/2023]
Abstract
Every living cell is a compartmentalized out-of-equilibrium system exquisitely able to convert chemical energy into function. In order to maintain homeostasis, the flux of metabolites is tightly controlled by regulatory enzymatic networks. A crucial prerequisite for the development of lifelike materials is the construction of synthetic systems with compartmentalized reaction networks that maintain out-of-equilibrium function. Here, we aim for autonomous movement as an example of the conversion of feedstock molecules into function. The flux of the conversion is regulated by a rationally designed enzymatic reaction network with multiple feedforward loops. By compartmentalizing the network into bowl-shaped nanocapsules the output of the network is harvested as kinetic energy. The entire system shows sustained and tunable microscopic motion resulting from the conversion of multiple external substrates. The successful compartmentalization of an out-of-equilibrium reaction network is a major first step in harnessing the design principles of life for construction of adaptive and internally regulated lifelike systems.
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Affiliation(s)
- Marlies Nijemeisland
- Institute
for Molecules and Materials, Radboud University
Nijmegen, Heyendaalseweg
135, 6525 AJ Nijmegen, The Netherlands
| | - Loai K. E. A. Abdelmohsen
- Institute
for Molecules and Materials, Radboud University
Nijmegen, Heyendaalseweg
135, 6525 AJ Nijmegen, The Netherlands
| | - Wilhelm T. S. Huck
- Institute
for Molecules and Materials, Radboud University
Nijmegen, Heyendaalseweg
135, 6525 AJ Nijmegen, The Netherlands
- E-mail:
| | - Daniela A. Wilson
- Institute
for Molecules and Materials, Radboud University
Nijmegen, Heyendaalseweg
135, 6525 AJ Nijmegen, The Netherlands
- E-mail:
| | - Jan C. M. van Hest
- Institute
for Molecules and Materials, Radboud University
Nijmegen, Heyendaalseweg
135, 6525 AJ Nijmegen, The Netherlands
- Department
of Biomedical Engineering and Chemical Engineering & Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands
- E-mail: ,
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Wiberg-Itzel E, Pembe AB, Järnbert-Pettersson H, Norman M, Wihlbäck AC, Hoesli I, Todesco Bernasconi M, Azria E, Åkerud H, Darj E. Lactate in Amniotic Fluid: Predictor of Labor Outcome in Oxytocin-Augmented Primiparas' Deliveries. PLoS One 2016; 11:e0161546. [PMID: 27783611 PMCID: PMC5082650 DOI: 10.1371/journal.pone.0161546] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 08/08/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND One of the major complications related to delivery is labor dystocia, or an arrested labor progress. Many dystocic deliveries end vaginally after administration of oxytocin, but a large numbers of women with labor dystocia will undergo a long and unsafe parturition. As a result of the exertion required in labor, the uterus produces lactate. The uterine production of lactate is mirrored by the level of lactate in amniotic fluid (AFL). OBJECTIVES To evaluate whether the level of AFL, analysed in a sample of amniotic fluid collected vaginally at arrested labor when oxytocin was needed, could predict labor outcome in nulliparous deliveries. METHODS A prospective multicentre study including 3000 healthy primiparous women all with a singleton pregnancy, gestational age 37 to 42 weeks and no maternal /fetal chronic and/or pregnancy-related conditions. A spontaneous onset of labor, regular contractions and cervical dilation ≥ 3 cm were required before the women were invited to take part in the study. RESULTS AFL, analysed within 30 minutes before augmentation, provides information about delivery outcome. Sensitivity for an acute cesarean section according to high (≥10.1mmol/l) or low (< 10.1mmol/l) AFL values was 39.0% (95% CI; 27-50), specificity 90.3% (95% CI; 87-93) PPV 37.3% (95% CI; 27-48) and NPV was 91.0% (95% CI; 88-93). The overall percentage of correct predictions of delivery outcome when the AFL level was used was 83.7%. Deliveries with a high AFL-level correlated with delivery time >12h (p = 0.04), post-partum fever (>38°C, p = 0.01) and post-partum haemorrhage >1.5L (p = 0.04). CONCLUSION The AFL is a good predictor of delivery outcome in arrested nulliparous deliveries. Low levels of AFL may support the decision to continue a prolonged vaginal labor by augmentation with oxytocin. A high level of AFL correlates with operative interventions and post-partum complications.
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Affiliation(s)
- Eva Wiberg-Itzel
- Department of Clinical Science and Education, Karolinska Institute, Soder Hospital, Stockholm, Sweden
| | - Andrea B. Pembe
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Hans Järnbert-Pettersson
- Department of Clinical Science and Education, Karolinska Institute, Soder Hospital, Stockholm, Sweden
| | | | | | | | | | - Elie Azria
- Hospital Bichat Claude Bernard, Paris, France
| | | | - Elisabet Darj
- KBH, Uppsala University, Uppsala, Sweden
- Norwegian University of Sciences and Technology, Trondheim, Norway
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Próchnicki T, Mangan MS, Latz E. Recent insights into the molecular mechanisms of the NLRP3 inflammasome activation. F1000Res 2016; 5. [PMID: 27508077 PMCID: PMC4963208 DOI: 10.12688/f1000research.8614.1] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/17/2016] [Indexed: 12/26/2022] Open
Abstract
Inflammasomes are high-molecular-weight protein complexes that are formed in the cytosolic compartment in response to danger- or pathogen-associated molecular patterns. These complexes enable activation of an inflammatory protease caspase-1, leading to a cell death process called pyroptosis and to proteolytic cleavage and release of pro-inflammatory cytokines interleukin (IL)-1β and IL-18. Along with caspase-1, inflammasome components include an adaptor protein, ASC, and a sensor protein, which triggers the inflammasome assembly in response to a danger signal. The inflammasome sensor proteins are pattern recognition receptors belonging either to the NOD-like receptor (NLR) or to the AIM2-like receptor family. While the molecular agonists that induce inflammasome formation by AIM2 and by several other NLRs have been identified, it is not well understood how the NLR family member NLRP3 is activated. Given that NLRP3 activation is relevant to a range of human pathological conditions, significant attempts are being made to elucidate the molecular mechanism of this process. In this review, we summarize the current knowledge on the molecular events that lead to activation of the NLRP3 inflammasome in response to a range of K (+) efflux-inducing danger signals. We also comment on the reported involvement of cytosolic Ca (2+) fluxes on NLRP3 activation. We outline the recent advances in research on the physiological and pharmacological mechanisms of regulation of NLRP3 responses, and we point to several open questions regarding the current model of NLRP3 activation.
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Affiliation(s)
- Tomasz Próchnicki
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany
| | - Matthew S Mangan
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany; German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Eicke Latz
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany; Department of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA, USA; German Center for Neurodegenerative Diseases, Bonn, Germany; Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
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Hanley JA, Weeks A, Wray S. Physiological increases in lactate inhibit intracellular calcium transients, acidify myocytes and decrease force in term pregnant rat myometrium. J Physiol 2015. [PMID: 26223765 PMCID: PMC4606541 DOI: 10.1113/jp270631] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Key points Lactate is increased in myometrial capillary blood from women in slow or non‐progressive labour (dystocia), suggesting that it is detrimental to uterine contractions. There are no studies of the effect of lactate on the myometrium. In the present study, we have investigated its effects and mechanism of action on myometrial strips from term pregnant rats. We show that lactate significantly decreased spontaneous contractility. Lactatedecreased pHi and inhibited Ca2+ transients. Nulling the decrease in pHi abolished the effects of lactate effects. If Ca2+ entry was enhanced, the effects of lactate were abolished. The present study suggests that the accumulation of extracellular lactate could contribute to labour dystocia.
Abstract Lactate is increased in myometrial capillary blood from women in slow or non‐progressive labour (dystocia), suggesting that it is detrimental to uterine contractions. There are, however, no studies of the effect of lactate on the myometrium. We therefore investigated its effects and mechanism of action on myometrial strips from term pregnant rats. The effects on spontaneous and oxytocin‐induced contractility in response to sodium lactate and other weak acids (1–20 mM) were studied. In some experiments, simultaneous force and intracellular Ca2+ or pH (pHi) were measured with Indo‐1 or Carboxy‐SNARF, respectively. Statistical differences were tested using non‐parametric tests. Lactate significantly decreased spontaneous contractility with an EC50 of 3.9 mM. Propionate, butyrate and pyruvate also reduced contractions with similar potency. The effects of lactate were reduced in the presence of oxytocin but remained significant. Lactate decreased pHi and nulling the decrease in pHi abolished its effects. We also show that lactate inhibited Ca2+ transients, with these changes mirroring those produced on force. If Ca2+ entry was enhanced by depolarization (high KCl) or applying the Ca2+ channel agonist, Bay K 4644, the effects of lactate were abolished. Taken together, these data show that lactate in the physiological range potently decreases myometrial contractility as a result of its inhibition of Ca2+ transients, which can be attributed to the induced acidification. The present study suggests that the accumulation of extracellular lactate will reduce myometrial contractions and could therefore contribute to labour dystocia.
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Affiliation(s)
| | - Andrew Weeks
- Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Susan Wray
- Departments of Cellular and Molecular Physiology
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Hypoxia-induced force increase (HIFI) is a novel mechanism underlying the strengthening of labor contractions, produced by hypoxic stresses. Proc Natl Acad Sci U S A 2015. [PMID: 26195731 DOI: 10.1073/pnas.1503497112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
For successful birth, contractions need to become progressively stronger. The underlying mechanisms are unknown, however. We have found that a novel mechanism, hypoxia-induced force increase (HIFI), is switched on selectively, at term, and is essential to strengthening contractions. HIFI is initiated as contractions cyclically reduce blood flow and produce repeated hypoxic stresses, with associated metabolic and transcriptomic changes. The increases in contractility are a long-lasting, oxytocin-independent, intrinsic mechanism present only in the full-term pregnant uterus. HIFI is inhibited by adenosine receptor antagonism and blockade of cyclooxygenase-2 signaling, and partially reproduced by brief episodes of acidic (but not alkalotic) pH. HIFI explains how labor can progress despite paradoxical metabolic challenge, and provides a new mechanistic target for the 1 in 10 women suffering dysfunctional labor because of poor contractions.
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Mumtaz S, AlSaif S, Wray S, Noble K. Inhibitory effect of visfatin and leptin on human and rat myometrial contractility. Life Sci 2015; 125:57-62. [DOI: 10.1016/j.lfs.2015.01.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 01/20/2015] [Accepted: 01/23/2015] [Indexed: 12/01/2022]
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Snášel J, Nauš P, Dostál J, Hnízda A, Fanfrlík J, Brynda J, Bourderioux A, Dušek M, Dvořáková H, Stolaříková J, Zábranská H, Pohl R, Konečný P, Džubák P, Votruba I, Hajdúch M, Rezáčová P, Veverka V, Hocek M, Pichová I. Structural basis for inhibition of mycobacterial and human adenosine kinase by 7-substituted 7-(Het)aryl-7-deazaadenine ribonucleosides. J Med Chem 2014; 57:8268-79. [PMID: 25259627 DOI: 10.1021/jm500497v] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Adenosine kinase (ADK) from Mycobacterium tuberculosis (Mtb) was selected as a target for design of antimycobacterial nucleosides. Screening of 7-(het)aryl-7-deazaadenine ribonucleosides with Mtb and human (h) ADKs and testing with wild-type and drug-resistant Mtb strains identified specific inhibitors of Mtb ADK with micromolar antimycobacterial activity and low cytotoxicity. X-ray structures of complexes of Mtb and hADKs with 7-ethynyl-7-deazaadenosine showed differences in inhibitor interactions in the adenosine binding sites. 1D (1)H STD NMR experiments revealed that these inhibitors are readily accommodated into the ATP and adenosine binding sites of Mtb ADK, whereas they bind preferentially into the adenosine site of hADK. Occupation of the Mtb ADK ATP site with inhibitors and formation of catalytically less competent semiopen conformation of MtbADK after inhibitor binding in the adenosine site explain the lack of phosphorylation of 7-substituted-7-deazaadenosines. Semiempirical quantum mechanical analysis confirmed different affinity of nucleosides for the Mtb ADK adenosine and ATP sites.
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Affiliation(s)
- Jan Snášel
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nam. 2, 16610 Prague 6, Czech Republic
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Wiberg-Itzel E, Pembe AB, Wray S, Wihlbäck AC, Darj E, Hoesli I, Åkerud H. Level of lactate in amniotic fluid and its relation to the use of oxytocin and adverse neonatal outcome. Acta Obstet Gynecol Scand 2014; 93:80-5. [PMID: 24102442 DOI: 10.1111/aogs.12261] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 09/06/2013] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To assess whether the frequency of adverse neonatal outcome at delivery is related to the level of lactate in amniotic fluid and to the use of oxytocin. DESIGN Prospective observational study. SETTING Soder Hospital, Stockholm, Sweden. POPULATION Seventy-four women in active labor with a gestational age ≥36 weeks and mixed parity. METHODS Levels of lactate in amniotic fluid were analyzed bedside from an intrauterine catheter every 30 min during labor. Deliveries were divided into groups with and without oxytocin. MAIN OUTCOME MEASURES The frequency of adverse neonatal outcome at delivery. RESULT Of the deliveries 13.5% (10/74) concluded with an adverse neonatal outcome. The levels of lactate in amniotic fluid increased during labor, more so in deliveries where oxytocin was used. In the group with an adverse neonatal outcome, the level of lactate in amniotic fluid was significantly higher in the final sample before delivery (p = 0.04). In 18 deliveries, stimulation with oxytocin was temporarily halted for at least 30 min due to overly stimulated labor contractions. A decreasing level of lactate in amniotic fluid was shown within a median 5%/30 min. In the group where the administration of oxytocin was halted, there was no adverse neonatal outcome. CONCLUSION The frequency of adverse neonatal outcome was associated with the level of lactate in amniotic fluid and with the use of oxytocin. The level of lactate in amniotic fluid may be an additional valuable tool when oxytocin is administered during labor.
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Affiliation(s)
- Eva Wiberg-Itzel
- Department of Clinical Science and Education, Section of Obstetrics and Gynecology, Karolinska Institute, Söder Hospital, Stockholm, Sweden
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Heyman NS, Cowles CL, Barnett SD, Wu YY, Cullison C, Singer CA, Leblanc N, Buxton ILO. TREK-1 currents in smooth muscle cells from pregnant human myometrium. Am J Physiol Cell Physiol 2013; 305:C632-42. [PMID: 23804201 PMCID: PMC3761174 DOI: 10.1152/ajpcell.00324.2012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 06/24/2013] [Indexed: 01/05/2023]
Abstract
The mechanisms governing maintenance of quiescence during pregnancy remain largely unknown. The current study characterizes a stretch-activated, tetraethylammonium-insensitive K(+) current in smooth muscle cells isolated from pregnant human myometrium. This study hypothesizes that these K(+) currents can be attributed to TREK-1 and that upregulation of this channel during pregnancy assists with the maintenance of a negative cell membrane potential, conceivably contributing to uterine quiescence until full term. The results of this study demonstrate that, in pregnant human myometrial cells, outward currents at 80 mV increased from 4.8 ± 1.5 to 19.4 ± 7.5 pA/pF and from 3.0 ± 0.8 to 11.8 ± 2.7 pA/pF with application of arachidonic acid (AA) and NaHCO3, respectively, causing intracellular acidification. Similarly, outward currents were inhibited following application of 10 μM fluphenazine by 51.2 ± 9.8% after activation by AA and by 73.9 ± 4.2% after activation by NaHCO3. In human embryonic kidney (HEK-293) cells stably expressing TREK-1, outward currents at 80 mV increased from 91.0 ± 23.8 to 247.5 ± 73.3 pA/pF and from 34.8 ± 8.9 to 218.6 ± 45.0 pA/pF with application of AA and NaHCO3, respectively. Correspondingly, outward currents were inhibited 89.5 ± 2.3% by 10 μM fluphenazine following activation by AA and by 91.6 ± 3.4% following activation by NaHCO3. Moreover, currents in human myometrial cells were activated by stretch and were reduced by transfection with small interfering RNA or extracellular acidification. Understanding gestational regulation of expression and gating of TREK-1 channels could be important in determining appropriate maintenance of uterine quiescence during pregnancy.
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Affiliation(s)
- Nathanael S Heyman
- Department of Pharmacology, Center for Molecular Medicine, University of Nevada School of Medicine, Reno, Nevada
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Lohman AW, Billaud M, Isakson BE. Mechanisms of ATP release and signalling in the blood vessel wall. Cardiovasc Res 2012; 95:269-80. [PMID: 22678409 DOI: 10.1093/cvr/cvs187] [Citation(s) in RCA: 236] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The nucleotide adenosine 5'-triphosphate (ATP) has classically been considered the cell's primary energy currency. Importantly, a novel role for ATP as an extracellular autocrine and/or paracrine signalling molecule has evolved over the past century and extensive work has been conducted to characterize the ATP-sensitive purinergic receptors expressed on almost all cell types in the body. Extracellular ATP elicits potent effects on vascular cells to regulate blood vessel tone but can also be involved in vascular pathologies such as atherosclerosis. While the effects of purinergic signalling in the vasculature have been well documented, the mechanism(s) mediating the regulated release of ATP from cells in the blood vessel wall and circulation are now a key target of investigation. The aim of this review is to examine the current proposed mechanisms of ATP release from vascular cells, with a special emphasis on the transporters and channels involved in ATP release from vascular smooth muscle cells, endothelial cells, circulating red blood cells, and perivascular sympathetic nerves, including vesicular exocytosis, plasma membrane F(1)/F(0)-ATP synthase, ATP-binding cassette (ABC) transporters, connexin hemichannels, and pannexin channels.
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Affiliation(s)
- Alexander W Lohman
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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Rizzo A, Angioni S, Spedicato M, Minoia G, Mutinati M, Trisolini C, Sciorsci RL. Uterine contractility is strongly influenced by steroids and glucose metabolism: an in vitro study on bovine myometrium. Gynecol Endocrinol 2011; 27:636-40. [PMID: 20695760 DOI: 10.3109/09513590.2010.507293] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Energetic substrates and hormonal phase are important for uterine contractions. Etomoxir a muscle carnitine palmitoyltransferase-1 inhibitor, able to diverge uterine metabolic pathways towards glycolysis, facilitates glucose utilisation. The aim of this study was to evaluate its effect on uterine contractility in different hormonal situations. METHODS Uterine samples were collected from 60 cows during follicular phase, luteal phase and pregnancy. The cows were slaughtered at a local abattoir. Longitudinal strips were mounted vertically in a 30-ml organ bath connected to an isometric force transducer. Contractions were recorded with an ink-writing polygraph. After the equilibration period, etomoxir was added to the organ bath at different concentrations. The amplitude and frequency of contractions were registered before and after addition of etomoxir. RESULTS In 17 strips from pregnant cows, etomoxir increased the amplitude (p < 0.05) of contractions but not the frequency in comparison with basal conditions. In 15 strips from cows in the luteal phase, etomoxir increased the amplitude (p < 0.05) and frequency of contractions (p < 0.05 at 5 μM and p < 0.01 at 8 and 10 μM). In 18 strips from cows in the follicular phase, etomoxir increased the frequency of contractions but not the amplitude (p < 0.01 at 5 μM and p < 0.05 at 8 and 10 μM). CONCLUSIONS This study confirms the importance of glucose for uterine contractility and, moreover, it underlines different patterns of contraction with regard to the hormonal status.
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Affiliation(s)
- Annalisa Rizzo
- Department of Animal Production, Faculty of Veterinary Medicine, University of Bari, Bari, Italy
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A role of stretch-activated potassium currents in the regulation of uterine smooth muscle contraction. Acta Pharmacol Sin 2011; 32:758-64. [PMID: 21642947 DOI: 10.1038/aps.2011.62] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Rates of premature birth are alarming and threaten societies and healthcare systems worldwide. Premature labor results in premature birth in over 50% of cases. Preterm birth accounts for three-quarters of infant morbidity and mortality. Children that survive birth before 34 weeks gestation often face life-long disability. Current treatments for preterm labor are wanting. No treatment has been found to be generally effective and none are systematically evaluated beyond 48 h. New approaches to the treatment of preterm labor are desperately needed. Recent studies from our laboratory suggest that the uterine muscle is a unique compartment with regulation of uterine relaxation unlike that of other smooth muscles. Here we discuss recent evidence that the mechanically activated 2-pore potassium channel, TREK-1, may contribute to contraction-relaxation signaling in uterine smooth muscle and that TREK-1 gene variants associated with human labor and preterm labor may lead to a better understanding of preterm labor and its possible prevention.
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Huang H, Zhang X, Li S, Liu N, Lian W, McDowell E, Zhou P, Zhao C, Guo H, Zhang C, Yang C, Wen G, Dong X, Lu L, Ma N, Dong W, Dou QP, Wang X, Liu J. Physiological levels of ATP negatively regulate proteasome function. Cell Res 2010; 20:1372-85. [PMID: 20805844 DOI: 10.1038/cr.2010.123] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Intracellular protein degradation by the ubiquitin-proteasome system is ATP dependent, and the optimal ATP concentration to activate proteasome function in vitro is ∼100 μM. Intracellular ATP levels are generally in the low millimolar range, but ATP at a level within this range was shown to inhibit proteasome peptidase activities in vitro. Here, we report new evidence that supports a hypothesis that intracellular ATP at the physiological levels bidirectionally regulates 26S proteasome proteolytic function in the cell. First, we confirmed that ATP exerted bidirectional regulation on the 26S proteasome in vitro, with the optimal ATP concentration (between 50 and 100 μM) stimulating proteasome chymotrypsin-like activities. Second, we found that manipulating intracellular ATP levels also led to bidirectional changes in the levels of proteasome-specific protein substrates in cultured cells. Finally, measures to increase intracellular ATP enhanced, while decreasing intracellular ATP attenuated the ability of proteasome inhibition to induce cell death. These data strongly suggest that endogenous ATP within the physiological concentration range can exert a negative impact on proteasome activities, allowing the cell to rapidly upregulate proteasome activity on ATP reduction under stress conditions.
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Affiliation(s)
- Hongbiao Huang
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical College, Guangzhou, Guangdong 510182, China
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Abstract
The sarcoplasmic reticulum (SR) of smooth muscles presents many intriguing facets and questions concerning its roles, especially as these change with development, disease, and modulation of physiological activity. The SR's function was originally perceived to be synthetic and then that of a Ca store for the contractile proteins, acting as a Ca amplification mechanism as it does in striated muscles. Gradually, as investigators have struggled to find a convincing role for Ca-induced Ca release in many smooth muscles, a role in controlling excitability has emerged. This is the Ca spark/spontaneous transient outward current coupling mechanism which reduces excitability and limits contraction. Release of SR Ca occurs in response to inositol 1,4,5-trisphosphate, Ca, and nicotinic acid adenine dinucleotide phosphate, and depletion of SR Ca can initiate Ca entry, the mechanism of which is being investigated but seems to involve Stim and Orai as found in nonexcitable cells. The contribution of the elemental Ca signals from the SR, sparks and puffs, to global Ca signals, i.e., Ca waves and oscillations, is becoming clearer but is far from established. The dynamics of SR Ca release and uptake mechanisms are reviewed along with the control of luminal Ca. We review the growing list of the SR's functions that still includes Ca storage, contraction, and relaxation but has been expanded to encompass Ca homeostasis, generating local and global Ca signals, and contributing to cellular microdomains and signaling in other organelles, including mitochondria, lysosomes, and the nucleus. For an integrated approach, a review of aspects of the SR in health and disease and during development and aging are also included. While the sheer versatility of smooth muscle makes it foolish to have a "one model fits all" approach to this subject, we have tried to synthesize conclusions wherever possible.
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Affiliation(s)
- Susan Wray
- Department of Physiology, School of Biomedical Sciences, University of Liverpool, Liverpool, Merseyside L69 3BX, United Kingdom.
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Abstract
A better understanding of the mechanisms that generate and modulate uterine contractility is needed if progress is to be made in the prevention or treatment of problems in labour. Dysfunctional labour describes the condition when uterine contractility is too poor to dilate the cervix, and it is the leading cause of emergency Caesarean sections. Recently, insight has been gained into a possible causal mechanism for dysfunctional labour. Study of the physiological mechanisms that produce excitation in the uterus, the subsequent Ca(2)(+) signals and biochemical pathway leading to contraction has underpinned this progress. In this review, I give an account of excitation-contraction signalling in the myometrium and explore the implications of recent findings concerning lipid rafts for these processes. I also discuss how changes of pH are fundamentally enmeshed in uterine activity and biochemistry and explore the effect that pH changes will have on human myometrium. Finally, I present the evidence that acidification of the myometrium is correlated with dysfunctional labour and suggest the processes by which it is occurring. It is only by gaining a better understanding of uterine physiology and pathophysiology that progress will be made and research findings translated into clinical benefit for women and their families.
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Affiliation(s)
- Susan Wray
- Department of Physiology, University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
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Kawamata M, Tonomura Y, Kimura T, Sugimoto Y, Yanagisawa T, Nishimori K. Oxytocin-induced phasic and tonic contractions are modulated by the contractile machinery rather than the quantity of oxytocin receptor. Am J Physiol Endocrinol Metab 2007; 292:E992-9. [PMID: 17148756 DOI: 10.1152/ajpendo.00492.2006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To investigate the relationship between the oxytocin (OT) receptor (OTR) quantity and the contractile features systematically, we measured the mRNA expression levels of OTR and L-type Ca(2+) channel alpha(1C)-subunit (alpha(1C)) and examined the regulatory mechanisms of OT-induced phasic or tonic contractions of the longitudinal smooth muscles in mouse uteri. The mRNA expression of OTR in 19.0 G (19.0 days of gestation) was greater than those in nonpregnant phases, and that of alpha(1C) in estrus and 19.0 G was higher than in diestrus. OT-induced contractions sparsely occurred in diestrus. The OT-induced all-or-none-type phasic contractions at low concentrations were abolished by verapamil in both estrus and 19.0 G. OT-induced tonic contractions had similar pD(2) values in both estrus and 19.0 G. However, the magnitude in 19.0 G was much greater than that in estrus. The large tonic contractions also occurred in PGF(2alpha) receptor (FP) knockout mice in 19.0 G despite a small amount of OTR. Verapamil and Y-27632 partially inhibited the tonic contractions in 19.0 G. Cyclopiazonic acid-induced tonic contractions were reciprocally decreased with the increase in the OT-induced ones in 19.0 G. These results indicate that the phasic contractions are dependent on alpha(1C). The tonic contractions in 19.0 G are dependent on both Ca(2+) influxes via L-type Ca(2+) channels and store-operated Ca(2+) channels, and the force is augmented by the Rho signal pathway, which increases the Ca(2+) sensitivity. Thus the uterine contractions are mainly controlled by the modification of contractile signal machinery rather than simply by the OTR quantity.
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Affiliation(s)
- Masaki Kawamata
- Department of Molecular Biology, Graduate School of Agriculture, Tohoku University, Sendai 981-8555, Japan
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Bugg GJ, Riley MJ, Johnston TA, Baker PN, Taggart MJ. Hypoxic inhibition of human myometrial contractions in vitro: implications for the regulation of parturition. Eur J Clin Invest 2006; 36:133-40. [PMID: 16436096 DOI: 10.1111/j.1365-2362.2006.01600.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Insufficient tissue oxygenation is a likely contribution to weak, inco-ordinate human uterine contractile activity characteristic of prolonged, dysfunctional labour. However, the direct effects of hypoxia on human myometrial contractility has, surprisingly, not yet been detailed. Therefore, we report the influence of hypoxia on spontaneous and agonist-induced carbachol, prostaglandin (PGF2alpha), and oxytocin contractions of myometria from nonpregnant and pregnant women. MATERIALS AND METHODS Uterine biopsies were obtained from pregnant women at term undergoing elective Caesarean section and nonpregnant women undergoing hysterectomy. Myometrial strips were equilibrated at 37 degrees C in normoxic physiological salt solution (95% air/5% CO(2)) and the influence of hypoxia (95% N(2)/5% CO(2)) on contractility was investigated. RESULTS Hypoxia resulted in a significant reduction in spontaneous contractile function; nonpregnant tissue was less resistant to the deleterious effects of hypoxia. Agonist-induced contractions, while being more resistant to hypoxia than spontaneous contractions, were also significantly inhibited. In myometria of pregnant women the PGF2alpha- or oxytocin-induced contractility was more resistant to hypoxia than carbachol. Finally, the inhibitory actions of hypoxia were exacerbated with repeated oxytocin administration with a more severe effect on contractile integral than on initial phasic contraction amplitude. CONCLUSIONS We detail, for the first time, the effects of hypoxia on contractility of human myometria from nonpregnant and pregnant women. Physiologically important uterotonic agents are more resistant to the effects of hypoxia than spontaneous contractions although repeated stimulation with oxytocin during hypoxia results in progressively less force. The results indicate that if significant hypoxia occurs in vivo then it is a likely contributory factor to the pathways underlying prolonged dysfunctional labour.
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Affiliation(s)
- G J Bugg
- Maternal & Fetal Health Research Centre, St Mary's Hospital, University of Manchester, Manchester, UK.
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Andersson KE, Arner A. Urinary bladder contraction and relaxation: physiology and pathophysiology. Physiol Rev 2004; 84:935-86. [PMID: 15269341 DOI: 10.1152/physrev.00038.2003] [Citation(s) in RCA: 607] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The detrusor smooth muscle is the main muscle component of the urinary bladder wall. Its ability to contract over a large length interval and to relax determines the bladder function during filling and micturition. These processes are regulated by several external nervous and hormonal control systems, and the detrusor contains multiple receptors and signaling pathways. Functional changes of the detrusor can be found in several clinically important conditions, e.g., lower urinary tract symptoms (LUTS) and bladder outlet obstruction. The aim of this review is to summarize and synthesize basic information and recent advances in the understanding of the properties of the detrusor smooth muscle, its contractile system, cellular signaling, membrane properties, and cellular receptors. Alterations in these systems in pathological conditions of the bladder wall are described, and some areas for future research are suggested.
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Affiliation(s)
- Karl-Erik Andersson
- Dept. of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
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48
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Abstract
OBJECTIVE Inefficient uterine contractions are the most common cause of poor progress in labor. The global increase in cesarean delivery rate is a cause of considerable concern, and the greatest reason for increase is the result of failure to progress in labor. Following in vitro studies that showed acidification could depress uterine contraction, we hypothesized that it could contribute to dysfunctional labors. METHODS A blood sample was taken from the lower segment of the uterus from women having a cesarean delivery, either electively or as a result of dysfunctional labor, and from those having a normal labor. This blood sample was analyzed for pH, O(2) saturation, and lactate levels. Contraction was recorded in myometrial strips, taken from women having elective cesarean delivery, at the pH of normally and dysfunctionally contracting uteri. RESULTS The pH of myometrial capillary blood from women having a dysfunctional labor was significantly lower (7.35) than that from women having elective cesarean delivery (7.49) or cesarean delivery with normal contractions, with (7.47) or without (7.48) oxytocin (P <.001). The women in dysfunctional labor had higher capillary lactate and lower capillary O(2) saturation. Furthermore, in vitro, reducing the pH value from 7.5 to 7.3 changes regular uterine contractions to irregular ones of reduced amplitude. CONCLUSIONS Myometrial lactic acidosis and a small decrease in O(2) saturation may be contributing factors to dysfunctional labor. Our data may also account for the ineffectiveness in management of dysfunctional labor with oxytocin. Oxytocin with a background of lactate acidosis may not be successful. LEVEL OF EVIDENCE II-2
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Affiliation(s)
- Siobhan Quenby
- Department of Obstetrics and Gynaecology, University of Liverpool, Liverpool, United Kingdom.
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Weirich J, Dumont L, Fleckenstein-Grün G. Contribution of store-operated Ca2+ entry to pHo-dependent changes in vascular tone of porcine coronary smooth muscle. Cell Calcium 2004; 35:9-20. [PMID: 14670367 DOI: 10.1016/s0143-4160(03)00156-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vascular smooth muscle contracts on increases of extracellular pH (pH(o)) and relaxes on pH(o) decreases possibly resulting from changes in transsarcolemmal Ca(2+) influx. Therefore, we studied store-operated Ca(2+) entry (SOCE; i.e. capacitative Ca(2+) entry (CCE)) during acidification (pH(o)=6.5) and alkalinization (pH(o)=8.0) in isolated porcine coronary smooth muscle cells (SMCs) by monitoring cytoplasmic Ca(2+) ([Ca(2+)](i)) and divalent cation entry (Mn(2+) quench) with fura-2/AM-fluorometry. Additionally, we evaluated the contribution of SOCE to pH(o)-dependent changes in isometric tension of porcine coronary smooth muscle strips. SOCE elicited in SMCs by the SERCA inhibitor BHQ was strongly modulated by pH(o) showing a decrease upon acidification and vice versa an increase upon alkalinization. BHQ-mediated tension of smooth muscle strips also revealed strong pH(o) dependence. In contrast, L-VOC-dependent tension ([K(+)](o)=20 and 40 mmol l(-1)) was remarkably less affected by pH(o) changes. Moreover, refilling of depleted Ca(2+) stores after repeated M(3)-cholinergic receptor stimulation could be almost completely inhibited by SKF 96365 and was markedly reduced by acidification and considerably enhanced by alkalinization pointing to a major role of SOCE in refilling. We conclude that vascular tone particularly responds to alterations in pH(o) whenever SOCE substantially contributes to the amount of activator Ca(2+) for contraction.
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Affiliation(s)
- Jörg Weirich
- Department of Physiology, University of Freiburg i. Br., Hermann-Herder-Strasse 7, D-79104 Freiburg, Germany
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50
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Monir-Bishty E, Pierce S, Kupittayanant S, Shmygol A, Wray S. The effects of metabolic inhibition on intracellular calcium and contractility of human myometrium. BJOG 2003. [DOI: 10.1111/j.1471-0528.2003.03103.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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