1
|
Lukowicz-Bedford RM, Eisen JS, Miller AC. Gap-junction-mediated bioelectric signaling required for slow muscle development and function in zebrafish. Curr Biol 2024; 34:3116-3132.e5. [PMID: 38936363 PMCID: PMC11265983 DOI: 10.1016/j.cub.2024.06.007] [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: 01/04/2024] [Revised: 04/11/2024] [Accepted: 06/04/2024] [Indexed: 06/29/2024]
Abstract
Bioelectric signaling, intercellular communication facilitated by membrane potential and electrochemical coupling, is emerging as a key regulator of animal development. Gap junction (GJ) channels can mediate bioelectric signaling by creating a fast, direct pathway between cells for the movement of ions and other small molecules. In vertebrates, GJ channels are formed by a highly conserved transmembrane protein family called the connexins. The connexin gene family is large and complex, creating challenges in identifying specific connexins that create channels within developing and mature tissues. Using the embryonic zebrafish neuromuscular system as a model, we identify a connexin conserved across vertebrate lineages, gjd4, which encodes the Cx46.8 protein, that mediates bioelectric signaling required for slow muscle development and function. Through mutant analysis and in vivo imaging, we show that gjd4/Cx46.8 creates GJ channels specifically in developing slow muscle cells. Using genetics, pharmacology, and calcium imaging, we find that spinal-cord-generated neural activity is transmitted to developing slow muscle cells, and synchronized activity spreads via gjd4/Cx46.8 GJ channels. Finally, we show that bioelectrical signal propagation within the developing neuromuscular system is required for appropriate myofiber organization and that disruption leads to defects in behavior. Our work reveals a molecular basis for GJ communication among developing muscle cells and reveals how perturbations to bioelectric signaling in the neuromuscular system may contribute to developmental myopathies. Moreover, this work underscores a critical motif of signal propagation between organ systems and highlights the pivotal role of GJ communication in coordinating bioelectric signaling during development.
Collapse
Affiliation(s)
| | - Judith S Eisen
- University of Oregon, Institute of Neuroscience, Eugene, OR 97405, USA
| | - Adam C Miller
- University of Oregon, Institute of Neuroscience, Eugene, OR 97405, USA.
| |
Collapse
|
2
|
Zhou C, Wang Y, He S, Lin S, Cheng J, Hu Q, Meng F, Gu T, Cai G, Li Z, Wu Z, Hong L. DIA-based quantitative proteomic analysis of porcine endometrium in the peri-implantation phase. J Proteomics 2024; 293:105065. [PMID: 38158016 DOI: 10.1016/j.jprot.2023.105065] [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: 07/18/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 01/03/2024]
Abstract
The 12th day of gestation is a critical period for embryo loss and the beginning of imminent implantation in sows. Data independent acquisition (DIA) technology is one of the high-throughput, high-resolution and reproducible proteomics technologies for large-scale digital qualitative and quantitative research. The aim of this study was to identify and characterize the protein abundance landscape of Yorkshire pig endometrium on the 12th day of pregnancy (P12) and estrous cycle (C12) using DIA proteomics. A total of 1251 differentially abundant proteins (DAPs) were identified, of which 882 were up-regulated and 369 were down-regulated at P12. Functional enrichment analysis showed that the identified proteins were related to metabolism, biosynthesis and signaling pathways. Three proteins were selected for Western blot (WB) validation and the results were consistent with the DIA data. Further combined with transcriptome data, fibrinogen like 2 (FGL2) and S100 calcium binding protein A8 (S100A8) were verified to be highly abundant in the P12 endometrial epithelium. In summary, there were significantly different abundance of proteome profiles in C12 and P12 endometrium, suggesting that DAPs are associated with changes in endometrial receptivity, which laid the foundation for further research on related regulatory mechanisms. SIGNIFICANCE: The 12th day of gestation is an important point in the peri-implantation period of pigs, when the endometrium presents a receptive state under the stimulation of estrogen. DIA proteomics technology is an emerging protein identification technology in recent years, which can obtain protein information through comprehensive and unbiased scanning. In this study, DIA technology was used to characterize endometrial proteins in pigs during the peri-implantation period. The results showed that higher protein abundance was detected using the DIA technique, and some of these DAPs may be involved in regulating embryo implantation. This study will help to better reveal the related proteins involved in embryo implantation, and lay a foundation for further research on the mechanism of endometrial regulation of embryo implantation. SIGNIFICANCE OF THE STUDY: The 12th day of gestation is an important point in the peri-implantation period of pigs, when the endometrium presents a receptive state under the stimulation of estrogen. DIA proteomics technology is an emerging protein identification technology in recent years, which can obtain protein information through comprehensive and unbiased scanning. In this study, DIA technology was used to characterize endometrial proteins in pigs during the peri-implantation period. The results showed that higher protein abundance was detected using the DIA technique, and some of these DAPs may be involved in regulating embryo implantation. This study will help to better reveal the related proteins involved in embryo implantation, and lay a foundation for further research on the mechanism of endometrial regulation of embryo implantation.
Collapse
Affiliation(s)
- Chen Zhou
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Yongzhong Wang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Simin He
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Shifei Lin
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Jie Cheng
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Qun Hu
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Fanming Meng
- Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Ting Gu
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Gengyuan Cai
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Zicong Li
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China
| | - Zhenfang Wu
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China; Yunfu Subcenter of Guangdong Laboratory for Lingnan Modern Agriculture, Yunfu, China; Key Laboratory of South China Modern Biological Seed Industry, Ministry of Agriculture and Rural Affairs, Guangzhou, China.
| | - Linjun Hong
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science, South China Agricultural University, Guangzhou, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou, China; Key Laboratory of South China Modern Biological Seed Industry, Ministry of Agriculture and Rural Affairs, Guangzhou, China.
| |
Collapse
|
3
|
Lukowicz-Bedford RM, Eisen JS, Miller AC. Gap junction mediated bioelectric coordination is required for slow muscle development, organization, and function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.20.572619. [PMID: 38187655 PMCID: PMC10769300 DOI: 10.1101/2023.12.20.572619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Bioelectrical signaling, intercellular communication facilitated by membrane potential and electrochemical coupling, is emerging as a key regulator of animal development. Gap junction (GJ) channels can mediate bioelectric signaling by creating a fast, direct pathway between cells for the movement of ions and other small molecules. In vertebrates, GJ channels are formed by a highly conserved transmembrane protein family called the Connexins. The connexin gene family is large and complex, presenting a challenge in identifying the specific Connexins that create channels within developing and mature tissues. Using the embryonic zebrafish neuromuscular system as a model, we identify a connexin conserved across vertebrate lineages, gjd4, which encodes the Cx46.8 protein, that mediates bioelectric signaling required for appropriate slow muscle development and function. Through a combination of mutant analysis and in vivo imaging we show that gjd4/Cx46.8 creates GJ channels specifically in developing slow muscle cells. Using genetics, pharmacology, and calcium imaging we find that spinal cord generated neural activity is transmitted to developing slow muscle cells and synchronized activity spreads via gjd4/Cx46.8 GJ channels. Finally, we show that bioelectrical signal propagation within the developing neuromuscular system is required for appropriate myofiber organization, and that disruption leads to defects in behavior. Our work reveals the molecular basis for GJ communication among developing muscle cells and reveals how perturbations to bioelectric signaling in the neuromuscular system_may contribute to developmental myopathies. Moreover, this work underscores a critical motif of signal propagation between organ systems and highlights the pivotal role played by GJ communication in coordinating bioelectric signaling during development.
Collapse
|
4
|
Koutras A, Fasoulakis Z, Syllaios A, Garmpis N, Diakosavvas M, Pagkalos A, Ntounis T, Kontomanolis EN. Physiology and Pathology of Contractility of the Myometrium. In Vivo 2021; 35:1401-1408. [PMID: 33910817 DOI: 10.21873/invivo.12392] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 02/16/2021] [Accepted: 02/19/2021] [Indexed: 11/10/2022]
Abstract
Uterine atony is a serious obstetrical complication since it is the leading cause of postpartum hemorrhage. Postpartum hemorrhage (PPH) is one of the 5 major causes of postpartum mortality; therefore, it requires immediate medical intervention, independent of whether delivery occurs normally or with a cesarean section. While in the past years most cases of postpartum hemorrhage were caused due to uterine atony following vaginal delivery, in recent years most PPH cases indicate a significant association with cesarean delivery. There are several methods used in order to avoid such a life-threatening complication, ranging from risk assessment to prevention, and finally medical intervention and management, if such an event occurs. In this scientific paper emphasis is given on the so-called "uterotonic" agents that are currently used, including oxytocin among others. It is, therefore, important to be familiar with these agents as well as understand the physiological mechanism by which they work, since they are used in everyday practice, not only for managing but also for preventing PPH. There are several potential questions that arise from the use of such "uterotonic" agents, and most specifically of oxytocin. Maybe one of the most important issues is the determination of optimal dosing of oxytocin in order to avoid PPH after a cesarean section.
Collapse
Affiliation(s)
- Antonios Koutras
- Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, General Hospital of Athens 'ALEXANDRA', Athens, Greece
| | - Zacharias Fasoulakis
- Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, General Hospital of Athens 'ALEXANDRA', Athens, Greece
| | - Athanasios Syllaios
- Department of Surgery, National and Kapodistrian University of Athens, Laikon General Hospital, Athens, Greece;
| | - Nikolaos Garmpis
- Department of Surgery, National and Kapodistrian University of Athens, Laikon General Hospital, Athens, Greece
| | - Michail Diakosavvas
- Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, General Hospital of Athens 'ALEXANDRA', Athens, Greece
| | - Athanasios Pagkalos
- Consultant on Department of Obstetrics and Gynecology, General Hospital of Xanthi, Xanthi, Greece
| | - Thomas Ntounis
- Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, General Hospital of Athens 'ALEXANDRA', Athens, Greece
| | - Emmanuel N Kontomanolis
- Department of Obstetrics and Gynecology, Democritus University of Thrace, Alexandroupolis, Greece
| |
Collapse
|
5
|
Malik M, Roh M, England SK. Uterine contractions in rodent models and humans. Acta Physiol (Oxf) 2021; 231:e13607. [PMID: 33337577 PMCID: PMC8047897 DOI: 10.1111/apha.13607] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 12/18/2022]
Abstract
Aberrant uterine contractions can lead to preterm birth and other labour complications and are a significant cause of maternal morbidity and mortality. To investigate the mechanisms underlying dysfunctional uterine contractions, researchers have used experimentally tractable small animal models. However, biological differences between humans and rodents change how researchers select their animal model and interpret their results. Here, we provide a general review of studies of uterine excitation and contractions in mice, rats, guinea pigs, and humans, in an effort to introduce new researchers to the field and help in the design and interpretation of experiments in rodent models.
Collapse
Affiliation(s)
- Manasi Malik
- Center for Reproductive Health SciencesDepartment of Obstetrics and GynecologyWashington University School of MedicineSt. LouisMOUSA
| | - Michelle Roh
- Center for Reproductive Health SciencesDepartment of Obstetrics and GynecologyWashington University School of MedicineSt. LouisMOUSA
| | - Sarah K. England
- Center for Reproductive Health SciencesDepartment of Obstetrics and GynecologyWashington University School of MedicineSt. LouisMOUSA
| |
Collapse
|
6
|
Garfield RE, Murphy L, Gray K, Towe B. Review and Study of Uterine Bioelectrical Waveforms and Vector Analysis to Identify Electrical and Mechanosensitive Transduction Control Mechanisms During Labor in Pregnant Patients. Reprod Sci 2020; 28:838-856. [PMID: 33090378 DOI: 10.1007/s43032-020-00358-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/11/2020] [Indexed: 12/15/2022]
Abstract
The bioelectrical signals that produce uterine contractions during parturition are not completely understood. The objectives are as follows: (1) to review the literature and information concerning uterine biopotential waveforms generated by the uterus, known to produce contractions, and evaluate mechanotransduction in pregnant patients using electromyographic (EMG) recording methods and (2) to study a new approach, uterine vector analysis, commonly used for the heart: vectorcardiography analysis. The patients used in this study were as follows: (1) patients at term not in labor (n = 3); (2) patients during the 1st stage of labor at cervical dilations from 2 to 10 cm (n = 30); and (3) patients in the 2nd stage of labor and during delivery (n = 3). We used DC-coupled electrodes and PowerLab hardware (model no. PL2604, ADInstruments, Castle Hill, Australia), with software (LabChart, ADInstruments) for storage and analysis of biopotentials. Uterine and abdominal EMG recordings were made from the surface of each patient using 3 electrode pairs with 1 pair (+ and -, with a 31-cm spacing distance) placed in the right/left position (X position) and with 1 pair placed in an up/down position (Y position, also 31 cm apart) and with the third pair at the front/back (Z position). Using signals from the three X, Y, and Z electrodes, slow (0.03 to 0.1 Hz, high amplitude) and fast wave (0.3 to 1 Hz, low amplitude) biopotentials were recorded. The amplitudes of the slow waves and fast waves were significantly higher during the 2nd stage of labor compared to the 1st stage (respectively, p = 9.54 × e-3 and p = 3.94 × e-7). When 2 channels were used, for example, the X vs. Y, for 2-D vector analysis or 3 channels, X vs. Y vs. Z, for 3-D analysis, are plotted against each other on their axes, this produces a vector electromyometriogram (EMMG) that shows no directionality for fast waves and a downward direction for slow waves. Similarly, during the 2nd stage of labor during abdominal contractions ("pushing"), the slow and fast waves were enlarged. Manual applied pressure was used to evoke bioelectrical activity to examine the mechanosensitivity of the uterus. Conclusions: (1) Phasic contractility of the uterus is a product of slow waves and groups of fast waves (bursts of spikes) to produce myometrial contractile responses. (2) 2-D and 3-D uterine vector analyses (uterine vector electromyometriogram) demonstrate no directionality of small fast waves while the larger slow waves represent the downward direction of biopotentials towards the cervical opening. (3) Myometrial cell action event excitability and subsequent contractility likely amplify slow wave activity input and uterine muscle contractility via mechanotransduction systems. (4) Models illustrate the possible relationships of slow to fast waves and the association of a mechanotransduction system and pacemaker activity as observed for slow waves and pacemakers in gastrointestinal muscle. (5) The interaction of these systems is thought to regulate uterine contractility. (6) This study suggests a potential indicator of delivery time. Such vector approaches might help us predict the progress of gestation and better estimate the timing of delivery, gestational pathologies reflected in bioelectric events, and perhaps the potential for premature delivery drug and mechanical interventions.
Collapse
Affiliation(s)
- R E Garfield
- Department of Obstetrics and Gynecology, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA.
| | - Lauren Murphy
- Department of Obstetrics and Gynecology, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Kendra Gray
- Department of Obstetrics and Gynecology, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Bruce Towe
- Department of Biomedical Engineering, Arizona State University, Tempe, AZ, USA
| |
Collapse
|
7
|
|
8
|
Garfield RE, Lucovnik M, Chambliss L, Qian X. Monitoring the onset and progress of labor with electromyography in pregnant women. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2019.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
9
|
Abstract
Pregnancy can be accompanied by serious health risks to mother and child, such as pre-eclampsia, premature birth and postpartum haemorrhage. Understanding of the normal physiology of uterine function is essential to an improved management of such risks. Here we focus on the physiology of the smooth muscle fibres which make up the bulk of the uterine wall and which generate the forceful contractions that accompany parturition. We survey computational methods that integrate mathematical modelling with data analysis and thereby aid the discovery of new therapeutic targets that, according to clinical needs, can be manipulated to either stop contractions or cause the uterine wall muscle to become active.
Collapse
Affiliation(s)
- Joseph R Dunford
- Cell and Developmental Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - E Josiah Lutton
- Department of Computer Science, University of Warwick, Coventry, UK
| | - Jolene Atia
- Health Informatics Research, Queen Elizabeth Hospital Birmingham, Birmingham, UK
| | - Andrew M Blanks
- Cell and Developmental Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | | |
Collapse
|
10
|
Mas-Cabo J, Ye-Lin Y, Garcia-Casado J, Alberola-Rubio J, Perales A, Prats-Boluda G. Uterine contractile efficiency indexes for labor prediction: A bivariate approach from multichannel electrohysterographic records. Biomed Signal Process Control 2018. [DOI: 10.1016/j.bspc.2018.07.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
11
|
Nader N, Hassan M, Falou W, Diab A, Al-Omar S, Khalil M, Marque C. Classification of pregnancy and labor contractions using a graph theory based analysis. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2015:2876-9. [PMID: 26736892 DOI: 10.1109/embc.2015.7318992] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this paper, we propose a new framework to characterize the electrohysterographic (EHG) signals recorded during pregnancy and labor. The approach is based on the analysis of the propagation of the uterine electrical activity. The processing pipeline includes i) the estimation of the statistical dependencies between the different recorded EHG signals, ii) the characterization of the obtained connectivity matrices using network measures and iii) the use of these measures in clinical application: the classification between pregnancy and labor. Due to its robustness to volume conductor, we used the imaginary part of coherence in order to produce the connectivity matrix which is then transformed into a graph. We evaluate the performance of several graph measures. We also compare the results with the parameter mostly used in the literature: the peak frequency combined with the propagation velocity (PV +PF). Our results show that the use of the network measures is a promising tool to classify labor and pregnancy contractions with a small superiority of the graph strength over PV+PF.
Collapse
|
12
|
Yochum M, Laforêt J, Marque C. Multi-scale and multi-physics model of the uterine smooth muscle with mechanotransduction. Comput Biol Med 2017; 93:17-30. [PMID: 29253628 DOI: 10.1016/j.compbiomed.2017.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 12/02/2017] [Accepted: 12/02/2017] [Indexed: 11/18/2022]
Abstract
Preterm labor is an important public health problem. However, the efficiency of the uterine muscle during labor is complex and still poorly understood. This work is a first step towards a model of the uterine muscle, including its electrical and mechanical components, to reach a better understanding of the uterus synchronization. This model is proposed to investigate, by simulation, the possible role of mechanotransduction for the global synchronization of the uterus. The electrical diffusion indeed explains the local propagation of contractile activity, while the tissue stretching may play a role in the synchronization of distant parts of the uterine muscle. This work proposes a multi-physics (electrical, mechanical) and multi-scales (cell, tissue, whole uterus) model, which is applied to a realistic uterus 3D mesh. This model includes electrical components at different scales: generation of action potentials at the cell level, electrical diffusion at the tissue level. It then links these electrical events to the mechanical behavior, at the cellular level (via the intracellular calcium concentration), by simulating the force generated by each active cell. It thus computes an estimation of the intra uterine pressure (IUP) by integrating the forces generated by each active cell at the whole uterine level, as well as the stretching of the tissue (by using a viscoelastic law for the behavior of the tissue). It finally includes at the cellular level stretch activated channels (SACs) that permit to create a loop between the mechanical and the electrical behavior (mechanotransduction). The simulation of different activated regions of the uterus, which in this first "proof of concept" case are electrically isolated, permits the activation of inactive regions through the stretching (induced by the electrically active regions) computed at the whole organ scale. This permits us to evidence the role of the mechanotransduction in the global synchronization of the uterus. The results also permit us to evidence the effect on IUP of this enhanced synchronization induced by the presence of SACs. This proposed simplified model will be further improved in order to permit a better understanding of the global uterine synchronization occurring during efficient labor contractions.
Collapse
Affiliation(s)
- Maxime Yochum
- Sorbonne University, Université de Technologie de Compiègne, CNRS UMR 7338, Biomechanics and Bioengineering, Centre de Recherche Royallieu, CS 60319-60203 Compiègne cedex, France.
| | - Jérémy Laforêt
- Sorbonne University, Université de Technologie de Compiègne, CNRS UMR 7338, Biomechanics and Bioengineering, Centre de Recherche Royallieu, CS 60319-60203 Compiègne cedex, France.
| | - Catherine Marque
- Sorbonne University, Université de Technologie de Compiègne, CNRS UMR 7338, Biomechanics and Bioengineering, Centre de Recherche Royallieu, CS 60319-60203 Compiègne cedex, France
| |
Collapse
|
13
|
Fang D, Moreno M, Garfield RE, Kuon R, Xia H. Optimal routes of administration, vehicles and timing of progesterone treatment for inhibition of delivery during pregnancy. Eur J Obstet Gynecol Reprod Biol 2017; 216:164-168. [PMID: 28777967 DOI: 10.1016/j.ejogrb.2017.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 04/20/2017] [Accepted: 06/01/2017] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Progestins, notably progesterone (P4) and 17 alpha hydroxyprogesterone caproate, are presently used to treat pregnant women at risk of preterm birth. The aim of this study was to assess the optimal treatment options for progesterone (P4) to delay delivery using a sensitive bioassay for progesterone. STUDY DESIGN Pregnant rats, known to be highly sensitive to progestins, were treated with P4, including Prochieve® (also known as Crinone®), in various vehicles from day 13 of gestation and in late gestation, days 19 to 22, and delivery times noted. Various routes of administration of P4 and various treatment periods were studied. RESULTS Use of micronized P4 by rectal, subcutaneous injection (sc) and topical (transdermal) administration in various oils all significantly (P<0.05-<0.001) delay delivery, but vaginal Prochieve® did not. Administration of P4 in late gestation also prevented (P<0.001) delivery even when given 8h before delivery. CONCLUSIONS Prochieve® possesses little biological activity to suppress delivery in a sensitive bioassay system and suggests that this preparation may be of little value in prevention and inhibition of preterm birth. Further, this study shows: 1) Inhibition of delivery is increased with P4 treatments when given subcutaneously or topically. 2) P4 in fish oil provides the best vehicle for topical treatment and may be an effective treatment of preterm birth. 3) P4 in fish oil also delays delivery even when treatment begins just prior to normal delivery. 4) To prevent preterm birth in pregnant women, randomized controlled studies are needed with a potent progestin using better formulations and routes of administration.
Collapse
Affiliation(s)
- Dajun Fang
- Southern Medical University, Guangzhou, China; Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Mario Moreno
- Stanford University School of Medicine, Stanford, CA, USA
| | - Robert E Garfield
- Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China; Department of Obstetrics and Gynecology, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Ruben Kuon
- Universitätsfrauenklinik Heidelberg, Abteilung für Gynäkologische Endokrinologie und Fertilitätsstörungen, 69120 Heidelberg, Germany
| | - Huimin Xia
- Southern Medical University, Guangzhou, China; Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
| |
Collapse
|
14
|
Nader N, Hassan M, Falou W, Marque C, Khalil M. A node-wise analysis of the uterine muscle networks for pregnancy monitoring. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:712-715. [PMID: 28268427 DOI: 10.1109/embc.2016.7590801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The recent past years have seen a noticeable increase of interest in the correlation analysis of electrohysterographic (EHG) signals in the perspective of improving the pregnancy monitoring. Here we propose a new approach based on the functional connectivity between multichannel (4×4 matrix) EHG signals recorded from the women's abdomen. The proposed pipeline includes i) the computation of the statistical couplings between the multichannel EHG signals, ii) the characterization of the connectivity matrices, computed by using the imaginary part of the coherence, based on the graph-theory analysis and iii) the use of these measures for pregnancy monitoring. The method was evaluated on a dataset of EHGs, in order to track the correlation between EHGs collected by each electrode of the matrix (called `node-wise' analysis) and follow their evolution along weeks before labor. Results showed that the strength of each node significantly increases from pregnancy to labor. Electrodes located on the median vertical axis of the uterus seemed to be the more discriminant. We speculate that the network-based analysis can be a very promising tool to improve pregnancy monitoring.
Collapse
|
15
|
Sheldon RE, Mashayamombe C, Shi SQ, Garfield RE, Shmygol A, Blanks AM, van den Berg HA. Alterations in gap junction connexin43/connexin45 ratio mediate a transition from quiescence to excitation in a mathematical model of the myometrium. J R Soc Interface 2015; 11:20140726. [PMID: 25401181 DOI: 10.1098/rsif.2014.0726] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The smooth muscle cells of the uterus contract in unison during delivery. These cells achieve coordinated activity via electrical connections called gap junctions which consist of aggregated connexin proteins such as connexin43 and connexin45. The density of gap junctions governs the excitability of the myometrium (among other factors). An increase in gap junction density occurs immediately prior to parturition. We extend a mathematical model of the myometrium by incorporating the voltage-dependence of gap junctions that has been demonstrated in the experimental literature. Two functional subtypes exist, corresponding to systems with predominantly connexin43 and predominantly connexin45, respectively. Our simulation results indicate that the gap junction protein connexin45 acts as a negative modulator of uterine excitability, and hence, activity. A network with a higher proportion of connexin45 relative to connexin43 is unable to excite every cell. Connexin45 has much more rapid gating kinetics than connexin43 which we show limits the maximum duration of a local burst of activity. We propose that this effect regulates the degree of synchronous excitation attained during a contraction. Our results support the hypothesis that as labour approaches, connexin45 is downregulated to allow action potentials to spread more readily through the myometrium.
Collapse
|
16
|
Romero R, Miranda J, Chaiworapongsa T, Korzeniewski SJ, Chaemsaithong P, Gotsch F, Dong Z, Ahmed AI, Yoon BH, Hassan SS, Kim CJ, Yeo L. Prevalence and clinical significance of sterile intra-amniotic inflammation in patients with preterm labor and intact membranes. Am J Reprod Immunol 2014; 72:458-74. [PMID: 25078709 DOI: 10.1111/aji.12296] [Citation(s) in RCA: 338] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 07/02/2014] [Indexed: 12/12/2022] Open
Abstract
PROBLEM Inflammation and infection play a major role in preterm birth. The purpose of this study was to (i) determine the prevalence and clinical significance of sterile intra-amniotic inflammation and (ii) examine the relationship between amniotic fluid (AF) concentrations of high mobility group box-1 (HMGB1) and the interval from amniocentesis to delivery in patients with sterile intra-amniotic inflammation. METHOD OF STUDY AF samples obtained from 135 women with preterm labor and intact membranes were analyzed using cultivation techniques as well as broad-range PCR and mass spectrometry (PCR/ESI-MS). Sterile intra-amniotic inflammation was defined when patients with negative AF cultures and without evidence of microbial footprints had intra-amniotic inflammation (AF interleukin-6 ≥ 2.6 ng/mL). RESULTS (i) The frequency of sterile intra-amniotic inflammation was significantly greater than that of microbial-associated intra-amniotic inflammation [26% (35/135) versus 11% (15/135); (P = 0.005)], (ii) patients with sterile intra-amniotic inflammation delivered at comparable gestational ages had similar rates of acute placental inflammation and adverse neonatal outcomes as patients with microbial-associated intra-amniotic inflammation, and (iii) patients with sterile intra-amniotic inflammation and high AF concentrations of HMGB1 (≥8.55 ng/mL) delivered earlier than those with low AF concentrations of HMGB1 (P = 0.02). CONCLUSION (i) Sterile intra-amniotic inflammation is more frequent than microbial-associated intra-amniotic inflammation, and (ii) we propose that danger signals participate in sterile intra-amniotic inflammation in the setting of preterm labor.
Collapse
Affiliation(s)
- Roberto Romero
- Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA; Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Detroit, MI, USA; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA; Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
BACKGROUND Understanding the physiology of pregnancy enables effective management of pregnancy complications that could otherwise be life threatening for both mother and fetus. A functional uterus (i) retains the fetus in utero during pregnancy without initiating stretch-induced contractions and (ii) is able to dilate the cervix and contract the myometrium at term to deliver the fetus. The onset of labour is associated with successful cervical remodelling and contraction of myometrium, arising from concomitant activation of uterine immune and endocrine systems. A large body of evidence suggests that actions of local steroid hormones may drive changes occurring in the uterine microenvironment at term. Although there have been a number of studies considering the potential role(s) played by progesterone and estrogen at the time of parturition, the bio-availability and effects of androgens during pregnancy have received less scrutiny. The aim of this review is to highlight potential roles of androgens in the biology of pregnancy and parturition. METHODS A review of published literature was performed to address (i) androgen concentrations, including biosynthesis and clearance, in maternal and fetal compartments throughout gestation, (ii) associations of androgen concentrations with adverse pregnancy outcomes, (iii) the role of androgens in the physiology of cervical remodelling and finally (iv) the role of androgens in the physiology of myometrial function including any impact on contractility. RESULTS Some, but not all, androgens increase throughout gestation in maternal circulation. The effects of this increase are not fully understood; however, evidence suggests that increased androgens might regulate key processes during pregnancy and parturition. For example, androgens are believed to be critical for cervical remodelling at term, in particular cervical ripening, via regulation of cervical collagen fibril organization. Additionally, a number of studies highlight potential roles for androgens in myometrial relaxation via non-genomic, AR-independent pathways critical for the pregnancy reaching term. Understanding of the molecular events leading to myometrial relaxation is an important step towards development of novel targeted tocolytic drugs. CONCLUSIONS The increase in androgen levels throughout gestation is likely to be important for establishment and maintenance of pregnancy and initiation of parturition. Further investigation of the underlying mechanisms of androgen action on cervical remodelling and myometrial contractility is needed. The insights gained may facilitate the development of new therapeutic approaches to manage pregnancy complications such as preterm birth.
Collapse
Affiliation(s)
- Sofia Makieva
- Medical Research Council Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom and Tommy's Centre for Maternal and Fetal Health, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - Philippa T K Saunders
- Medical Research Council Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom and
| | - Jane E Norman
- Medical Research Council Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom and Tommy's Centre for Maternal and Fetal Health, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| |
Collapse
|
18
|
Nielsen MS, Axelsen LN, Sorgen PL, Verma V, Delmar M, Holstein-Rathlou NH. Gap junctions. Compr Physiol 2013; 2:1981-2035. [PMID: 23723031 DOI: 10.1002/cphy.c110051] [Citation(s) in RCA: 298] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease.
Collapse
Affiliation(s)
- Morten Schak Nielsen
- Department of Biomedical Sciences and The Danish National Research Foundation Centre for Cardiac Arrhythmia, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | | | | |
Collapse
|
19
|
Tan H, Yi L, Rote NS, Hurd WW, Mesiano S. Progesterone receptor-A and -B have opposite effects on proinflammatory gene expression in human myometrial cells: implications for progesterone actions in human pregnancy and parturition. J Clin Endocrinol Metab 2012; 97:E719-30. [PMID: 22419721 PMCID: PMC3339884 DOI: 10.1210/jc.2011-3251] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
CONTEXT Progesterone promotes uterine relaxation during pregnancy and its withdrawal induces labor. Progesterone withdrawal in human parturition is mediated in part by changes in the relative levels of the nuclear progesterone receptor isoforms, PR-A and PR-B, in myometrial cells. Parturition also involves myometrial inflammation; however, the functional link between nuclear PR-mediated progesterone actions and inflammation in human myometrial cells is unclear. OBJECTIVE Our objective was to determine how PR-A and PR-B regulate progesterone action in human myometrial cells and specifically the expression of genes encoding contraction-associated proteins and proinflammatory mediators. DESIGN Effects of PR-A and PR-B on the capacity for progesterone to modulate gene expression was determined using an immortalized human myometrial cell line stably transfected with inducible PR-A and PR-B expression transgenes and conditioned to express various PR-A and PR-B levels. Gene expression was assessed by genome wide transcriptome analysis, quantitative RT-PCR and immunoblotting. RESULTS PR-A and PR-B were each transcriptionally active in response to progesterone and affected the expression of distinct gene cohorts. The capacity for progesterone to affect gene expression was dependent on the PR-A to PR-B ratio. This was especially apparent for the expression of proinflammatory genes. Progesterone decreased proinflammatory gene expression when the PR-A to PR-B ratio favored PR-B and increased proinflammatory gene expression when the ratio favored PR-A. Progesterone via PR-B increased expression of inhibitor-κBα, a repressor of the nuclear factor-κB transcription factor, and inhibited basal and lipopolysaccharide-induced proinflammatory gene expression. Both of those PR-B-mediated effects were inhibited by PR-A. CONCLUSIONS Our data suggest that during most of human pregnancy, when myometrial cells are PR-B dominant, progesterone promotes myometrial quiescence through PR-B-mediated antiinflammatory actions. At parturition, the rise in PR-A expression promotes labor by inhibiting the antiinflammatory actions of PR-B and stimulating proinflammatory gene expression in response to progesterone.
Collapse
Affiliation(s)
- Huiqing Tan
- Department of Reproductive Biology, Case Western Reserve University, 11100 Euclid Avenue, Cleveland Ohio 44106-5034, USA
| | | | | | | | | |
Collapse
|
20
|
[Evolution of electrohysterogram signals synchronization according to term of pregnancy: interest for preterm labor diagnosis]. GYNECOLOGIE, OBSTETRIQUE & FERTILITE 2012; 40:344-9. [PMID: 22483715 DOI: 10.1016/j.gyobfe.2012.02.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 02/22/2012] [Indexed: 11/21/2022]
Abstract
OBJECTIVES Our study focuses on the analysis of the uterine electromyogram recorded on women during pregnancy. We were interested in evaluating the synchronization of this electrical signal at various terms in order to follow evolution of synchronization as labor approaches. This study attempts to deepen our understanding of the myometrial maturation close to labor and to provide reliable parameters for improving preterm labor diagnosis. PATIENTS AND METHODS We performed a prospective study by recording the electrical signals of physiological uterine contractions (causing no delivery) on 16 pregnant women. We then calculated the non-linear correlation coefficient h(2) to estimate synchronization between EMG signals collected for each contraction. We expressed the results by grouping synchronization values by class of term in order to study the evolution of this coefficient along gestation. This study has been approved by the ethical committee of our hospital. RESULTS Our results show a non-significant increase of the h(2) value along term. There is however a trend towards an increase of the synchronization of EMG signals as labor approaches but not enough to conclude definitively. DISCUSSION AND CONCLUSION With a confirmation of the increase of h(2) along term, the study of the synchronization of uterine electrical activity could be an important clue to support the notion of myometrial maturation close to labor. Synchronization analysis could also be a promising parameter for reliable diagnosis of preterm labor.
Collapse
|
21
|
Romero R, Chaiworapongsa T, Alpay Savasan Z, Xu Y, Hussein Y, Dong Z, Kusanovic JP, Kim CJ, Hassan SS. Damage-associated molecular patterns (DAMPs) in preterm labor with intact membranes and preterm PROM: a study of the alarmin HMGB1. J Matern Fetal Neonatal Med 2011; 24:1444-55. [PMID: 21958433 PMCID: PMC3419589 DOI: 10.3109/14767058.2011.591460] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Preterm parturition is a syndrome caused by multiple etiologies. Although intra-amniotic infection is causally linked with intrauterine inflammation and the onset of preterm labor, other patients have preterm labor in the absence of demonstrable infection. It is now clear that inflammation may be elicited by activation of the Damage-Associated Molecular Patterns (DAMPs), which include pathogen-associated molecular patterns (PAMPs) as well as "alarmins" (endogenous molecules that signal tissue and cellular damage). A prototypic alarmin is high-mobility group box 1 (HMGB1) protein, capable of inducing inflammation and tissue repair when it reaches the extracellular environment. HMGB1 is a late mediator of sepsis, and blockade of HMGB1 activity reduces mortality in an animal model of endotoxemia, even if administered late during the course of the disorder. The objectives of this study were to: (1) determine whether intra-amniotic infection/inflammation (IAI) is associated with changes in amniotic fluid concentrations of HMGB1; and (2) localize immunoreactivity of HMGB1 in the fetal membranes and umbilical cord of patients with chorioamnionitis. METHODS Amniotic fluid samples were collected from the following groups: (1) preterm labor with intact membranes (PTL) with (n=42) and without IAI (n=84); and (2) preterm prelabor rupture of membranes (PROM) with (n=38) and without IAI (n=35). IAI was defined as either a positive amniotic fluid culture or amniotic fluid concentration of interleukin-6 (IL-6) ≥ 2.6ng/mL. HMGB1 concentrations in amniotic fluid were determined by ELISA. Immunofluorescence staining for HMGB1 was performed in the fetal membranes and umbilical cord of pregnancies with acute chorioamnionitis. RESULTS (1) Amniotic fluid HMGB1 concentrations were higher in patients with IAI than in those without IAI in both the PTL and preterm PROM groups (PTL IAI: median 3.1 ng/mL vs. without IAI; median 0.98 ng/mL; p <0.001; and preterm PROM with IAI median 7.3 ng/mL vs. without IAI median 2.6 ng/mL; p=0.002); (2) patients with preterm PROM without IAI had a higher median amniotic fluid HMGB1 concentration than those with PTL and intact membranes without IAI (p <0.001); and (3) HMGB1 was immunolocalized to amnion epithelial cells and stromal cells in the Wharton's jelly (prominent in the nuclei and cytoplasm). Myofibroblasts and macrophages of the chorioamniotic connective tissue layer and infiltrating neutrophils showed diffuse cytoplasmic HMGB1 immunoreactivity. CONCLUSIONS (1) intra-amniotic infection/inflammation is associated with elevated amniotic fluid HMGB1 concentrations regardless of membrane status; (2) preterm PROM was associated with a higher amniotic fluid HMGB1 concentration than PTL with intact membranes, suggesting that rupture of membranes is associated with an elevation of alarmins; (3) immunoreactive HMGB1 was localized to amnion epithelial cells, Wharton's jelly and cells involved in the innate immune response; and (4) we propose that HMGB1 released from stress or injured cells into amniotic fluid may be responsible, in part, for intra-amniotic inflammation due to non-microbial insults.
Collapse
Affiliation(s)
- Roberto Romero
- Perinatology Research Branch, NICHD/NIH/DHHS, Wayne State University/Hutzel Women’s Hospital, 3990 John R, Detroit, MI 48201, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Vrachnis N, Malamas FM, Sifakis S, Tsikouras P, Iliodromiti Z. Immune aspects and myometrial actions of progesterone and CRH in labor. Clin Dev Immunol 2011; 2012:937618. [PMID: 22028729 PMCID: PMC3199111 DOI: 10.1155/2012/937618] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 08/17/2011] [Indexed: 01/12/2023]
Abstract
Progesterone and corticotropin-releasing hormone (CRH) have a critical role in pregnancy and labor, as changes related to these hormones are crucial for the transition from myometrial quiescence to contractility. The mechanisms related to their effect differ between humans and other species, thus, despite extensive research, many questions remain to be answered regarding their mediation in human labor. Immune responses to progesterone and CRH are important for labor. Progesterone acts as an immunomodulator which controls many immune actions during pregnancy, and its withdrawal releases the inhibitory action on inflammatory pathways. In humans, a "functional" progesterone withdrawal occurs with onset of labor through changes in progesterone metabolism, progesterone receptors, and other molecules that either facilitate or antagonize progesterone function. Placental CRH acts on the fetal pituitary-adrenal axis to stimulate adrenal production of androgens and cortisol and also acts directly on myometrial cells via its receptors. CRH also affects inflammatory signals and vice versa. Interactions between progesterone and CRH additionally occur during labor. We describe the role of these two hormones in human myometrium and their interactions with the immune system during labor.
Collapse
Affiliation(s)
- Nikolaos Vrachnis
- 2nd Department of Obstetrics and Gynecology, University of Athens Medical School, Aretaieio Hospital, 11528 Athens, Greece.
| | | | | | | | | |
Collapse
|
23
|
Vrachnis N, Malamas FM, Sifakis S, Deligeoroglou E, Iliodromiti Z. The oxytocin-oxytocin receptor system and its antagonists as tocolytic agents. Int J Endocrinol 2011; 2011:350546. [PMID: 22190926 PMCID: PMC3235456 DOI: 10.1155/2011/350546] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Accepted: 09/25/2011] [Indexed: 12/29/2022] Open
Abstract
Oxytocin, a hormone involved in numerous physiologic processes, plays a central role in the mechanisms of parturition and lactation. It acts through its receptor, which belongs to the G-protein-coupled receptor superfamily, while Gq/phospholipase C (PLC)/inositol 1,4,5-triphosphate (InsP3) is the main pathway via which it exerts its action in the myometrium. Changes in receptor levels, receptor desensitization, and locally produced oxytocin are factors that influence the effect of oxytocin on uterine contractility in labor. Activation of oxytocin receptor causes myometrial contractions by increasing intracellular Ca(+2) and production of prostaglandins. Since oxytocin induces contractions, the inhibition of its action has been a target in the management of preterm labor. Atosiban is today the only oxytocin receptor antagonist that is available as a tocolytic. However, the quest for oxytocin receptor antagonists with a better pharmacological profile has led to the synthesis of peptide and nonpeptide molecules such as barusiban, retosiban, L-368,899, and SSR-126768A. Many of these oxytocin receptor antagonists are used only as pharmacological tools, while others have tocolytic action. In this paper, we summarize the action of oxytocin and its receptor and we present an overview of the clinical and experimental data of oxytocin antagonists and their tocolytic action.
Collapse
Affiliation(s)
- Nikolaos Vrachnis
- 2nd Department of Obstetrics and Gynecology, Aretaieio Hospital, University of Athens Medical School, 11526 Athens, Greece
- *Nikolaos Vrachnis:
| | - Fotodotis M. Malamas
- 1st Department of Obstetrics and Gynecology, Alexandra Hospital, University of Athens Medical School, 11526 Athens, Greece
| | - Stavros Sifakis
- Department of Obstetrics and Gynaecology, University Hospital of Heraklion, 71110 Heraklion, Crete, Greece
| | - Efthymios Deligeoroglou
- 2nd Department of Obstetrics and Gynecology, Aretaieio Hospital, University of Athens Medical School, 11526 Athens, Greece
| | - Zoe Iliodromiti
- 2nd Department of Obstetrics and Gynecology, Aretaieio Hospital, University of Athens Medical School, 11526 Athens, Greece
| |
Collapse
|
24
|
Affiliation(s)
- Sam Mesiano
- Departments of Reproductive Biology and Obstetrics & Gynecology, University Hospitals Case Medical Center, Cleveland, OH, USA
| | - Yuguang Wang
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Errol R. Norwitz
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| |
Collapse
|
25
|
Abstract
Almost 80 years ago George Corner and colleagues provided the first evidence that progesterone maintains pregnancy and that it does so, at least in part, by promoting myometrial relaxation. In the 1950s, Arpad Csapo proposed the “progesterone block hypothesis”, which posits that progesterone maintains pregnancy by promoting myometrial relaxation and that its withdrawal initiates a cascade of hormonal interactions that transforms the myometrium to a highly contractile state leading to the onset of labour. Csapo later proposed that contractility of the pregnant myometrium is determined by the balance between relaxation induced by progesterone and contraction induced by a cohort of signals including oestrogens, uterine distention and stimulatory uterotonins such as prostaglandins (PGs) and oxytocin (OT). According to this “seesaw” hypothesis, progesterone promotes myometrial relaxation by directly inducing relaxation and/or by inhibiting the production of, or myometrial responsiveness to, stimulatory uterotonins. These landmark concepts, though derived from studies of experimental animals, form the foundation for current understanding of progesterone's role in the physiology of human pregnancy. Remarkable progress has been made over the last 20–30 years in understanding the signal transduction pathways through which steroid hormones affect target cells. This knowledge has broadened the scope of Csapo's original paradigms and we are now beginning to unravel the specific signaling pathways and molecular interactions by which progesterone affects human myometrium and how its actions are controlled at the functional level. This is important for the development of progestin-based therapeutics for the prevention or suppression of preterm labour and preterm birth. Here we review recent progress in understanding the mechanisms by which progesterone sustains pregnancy and in particular how it promotes myometrial relaxation, how its relaxatory actions are nullified at parturition, and the hormonal interactions that induce progesterone withdrawal to determine the timing of human birth.
Collapse
|
26
|
Physiology of myometrial function: intercellular coupling and its role in uterine contractility. ACTA ACUST UNITED AC 2008. [DOI: 10.1017/s096553950000053x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The mammalian uterus is composed of a preponderance of small smooth muscle cells usually aligned in two layers. The number of muscle cells in the human uterus at term is estimated at 200 billion, each minute fusiform cell measuring about 5–10μm in diameter and about 200μm in length. The main function of the uterus is to harbour the developing fetus during pregnancy and then to contract vigorously during labour to expel the products of conception. In order for the uterus to contract rhythmically and forcefully, a mechanism must exist to allow interaction between muscle cells in order to achieve synchronous activity. Phasic or cyclical patterns of contractile activity of the uterus cannot be accounted for by stimulation or inhibition from the nervous or endocrine systems. Since myometrial cells are dependent upon action potentials for their contractile processes, some system must be present between the muscle cells for the propagation of action potentials between them. The observation that gap junctions occur in large numbers between myometrial cells during parturition is thought to be significant in this regard and they are considered to play an essential role in parturition and in the control and co-ordination of uterine contractility. In this brief review, we will discuss the role of gap junctions in the modulation of myometrial contractility and the mechanisms that regulate their synthesis and permeability.
Collapse
|
27
|
Suri R, Hellemann G, Cohen L, Aquino A, Altshuler L. Saliva estriol levels in women with and without prenatal antidepressant treatment. Biol Psychiatry 2008; 64:533-7. [PMID: 18495086 PMCID: PMC2562039 DOI: 10.1016/j.biopsych.2008.04.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 01/31/2008] [Accepted: 04/09/2008] [Indexed: 10/22/2022]
Abstract
BACKGROUND Prenatal antidepressant use has been associated with shorter pregnancy duration and an increased risk for preterm birth. This study measured saliva levels of estriol, a hormone that increases exponentially in the few weeks before spontaneous labor, in pregnant women with and without antidepressant treatment. METHODS Saliva estriol levels were obtained across the day at three time points during pregnancy in 77 subjects with a history of DSM-IV major depressive disorder (MDD) who were treated with antidepressants in pregnancy (Group 1), a history of DSM-IV MDD who were not treated or had limited exposure to antidepressants during pregnancy (Group 2), and a normal control group (Group 3). RESULTS Mean estriol levels in the second half of pregnancy were significantly higher for Group 1 (history of MDD, on meds) than Group 2 (history of MDD, off meds) or Group 3 (control). CONCLUSIONS Prenatal antidepressant use was associated with significantly higher saliva estriol levels in the second half of pregnancy. Whether estriol reflects a causal mechanism by which women on antidepressants have shorter pregnancy duration remains to be further studied.
Collapse
Affiliation(s)
- Rita Suri
- Mood Disorders Research Program, Department of Psychiatry, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA.
| | | | | | | | | |
Collapse
|
28
|
Abstract
One of the most important stages of pregnancy is the activation of uterine contractions that result in the expulsion of the fetus. The timely onset of labour is clearly important for a healthy start to life but incomplete understanding of the precise mechanisms regulating labour onset have prohibited the development of effective and safe treatments for preterm labour. This review explores the activation of the myometrium at labour onset, focussing on mechanisms of uterine contractility, including those proteins that play an important role in smooth muscle contractility. The review primarily focuses on human work but in the absence of human data describes animal studies. A broad overview of myometrial contraction mechanisms is provided before discussing more detailed aspects and identifying areas where uncertainty remains. Also discussed is the recent application of ‘omics’ based approaches to parturition research, which has facilitated an increase in the understanding of myometrial activation.
Collapse
|
29
|
Abstract
Preterm birth remains a major cause of perinatal mortality and long term handicap in surviving infants. This is one of the most important clinical problems in Europe and across the world. While some preterm births are iatrogenic, associated with severe complications of pregnancy (e.g. hypertensive disorders, antepartum haemorrhage, infection), or the result of multiple pregnancies following assisted reproduction, a high proportion of preterm births occur following spontaneous preterm labour of unknown cause. Early intervention in this group of women would have a significant impact on neonatal mortality and morbidity figures. However, the endocrine changes preceding parturition in women remain elusive and this makes it difficult to predict spontaneous labour at term, let alone preterm labour. Moreover our understanding of myometrial physiology remains rudimentary, limiting our options to devise improved pharmacological strategies to control uterine contractility when this is indicated. There is a need for concerted European and international research efforts to improve our knowledge of the mechanism of labour in women, to identify diagnostic markers to predict preterm labour and to develop uterine selective drugs to inhibit uterine contractions in a safe and efficient manner. This aim will be achieved by multidisciplinary research efforts from academics and industry, using traditional laboratory and clinical research methods, as well as novel technologies.
Collapse
Affiliation(s)
- Andrés López Bernal
- University of Bristol, Clinical Science at South Bristol (Obstetrics and Gynaecology), St Michael's Hospital and Dorothy Hodgkin Building, Bristol, UK.
| |
Collapse
|
30
|
Mesiano S, Welsh TN. Steroid hormone control of myometrial contractility and parturition. Semin Cell Dev Biol 2007; 18:321-31. [PMID: 17613262 DOI: 10.1016/j.semcdb.2007.05.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 05/03/2007] [Indexed: 01/04/2023]
Abstract
The precise temporal control of uterine contractility is essential for the success of pregnancy. For most of pregnancy, progesterone acting through genomic and non-genomic mechanisms promotes myometrial relaxation. At parturition the relaxatory actions of progesterone are nullified and the combined stimulatory actions of estrogens and other factors such as myometrial distention and immune/inflammatory cytokines, transform the myometrium to a highly contractile and excitable state leading to labor and delivery. This review addresses current understanding of how progesterone and estrogens affect the contractility of the pregnancy myometrium and how their actions are coordinated and controlled as part of the parturition cascade.
Collapse
Affiliation(s)
- Sam Mesiano
- Department of Reproductive Biology, Case Western Reserve University, 11100 Euclid Avenue, Cleveland, OH 44106-5034, United States.
| | | |
Collapse
|
31
|
Cella M, Aisemberg J, Sordelli MS, Billi S, Farina M, Franchi AM, Ribeiro ML. Prostaglandins modulate nitric oxide synthase activity early in time in the uterus of estrogenized rat challenged with lipopolysaccharide. Eur J Pharmacol 2006; 534:218-26. [PMID: 16490189 DOI: 10.1016/j.ejphar.2006.01.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 01/03/2006] [Accepted: 01/11/2006] [Indexed: 01/22/2023]
Abstract
The aim of our study was to investigate if the lipopolysaccharide (LPS) differentially modulates throughout time the nitric oxide synthase (NOS) and cyclooxygenase (COX) enzymes in the estrogenized rat uterus. To study the effect of LPS throughout time on nitric oxide and prostaglandins production and on NOS and COX expression in the estrogenized rat uterus, females received 5 mg/kg intraperitoneally (i.p.) of LPS and were sacrificed 0.5, 1, 2, 3, 4 and 5 h post-administration. NO production was measured by arginine-citrulline conversion assay and prostaglandin E2/prostaglandin F2alpha by radioconversion. Enzyme expression was evaluated by Western blot analysis. The present work shows that LPS augmented NOS activity 3 h post-treatment and iNOS expression earlier, 2 h post-administration. On the other hand, the administration of LPS stimulated the production of prostaglandin E2/prostaglandin F2alpha and augmented the expression of COX-I 1 h after the treatment and of COX-II 2 h post-treatment. Meloxicam, a COX-II inhibitor, stimulated NO production in a group of rats injected i.p. with both LPS and the inhibitor and sacrificed 2 h after the treatment. These results indicate that, in the estrogenized rat uterus challenged with LPS, the early stimulation in the production of prostaglandins inhibited NOS activity, until the expression of the NOS isoforms is sufficient to overpass the inhibitory effect of the prostaglandins. The above findings suggest that the interaction between NOS and COX might be important in the regulation of physiopathologic events during pregnancy.
Collapse
Affiliation(s)
- Maximiliano Cella
- Laboratory of Physiopathology of Pregnancy and Labor, Center for Pharmacological and Botanical Studies, CONICET, School of Medicine, University of Buenos Aires, Paraguay 2155, 16th floor, ZIP code C1121ABG, Buenos Aires, Argentina
| | | | | | | | | | | | | |
Collapse
|
32
|
Caruso RL, Upham BL, Harris C, Trosko JE. Biphasic lindane-induced oxidation of glutathione and inhibition of gap junctions in myometrial cells. Toxicol Sci 2005; 86:417-26. [PMID: 15901910 DOI: 10.1093/toxsci/kfi208] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The insecticide lindane (gamma-hexachlorocyclohexane) inhibits gap junction intercellular communication in rat myometrial cells by a mechanism involving oxidative stress. We hypothesized that oxidation of reduced glutathione (GSH) to glutathione disulfide (GSSG) and subsequent S-glutathionylation provide a mechanistic link between lindane-induced oxidative stress and lindane's inhibition of myometrial gap junction communication. Gap junction communication between cultured rat myometrial myocytes was assessed by Lucifer yellow dye transfer after microinjection. A biphasic pattern was confirmed, with dye transfer nearly abolished after 1 h of exposure to 100 microM lindane followed initially by recovery after lindane removal, and then the development 4 h after termination of lindane exposure of a delayed-onset, sustained inhibition that continued for 96 h. As measured by HPLC, cellular GSH varied over a 24-h period in a biphasic fashion that paralleled lindane-induced inhibition of dye transfer, whereas GSSG levels increased in a manner inversely related to GSH. In accordance, GSH/GSSG ratios were depressed at times when GSH and dye transfer were low. Lindane substantially increased S-glutathionylation in a concentration-dependent manner, measured biochemically by GSSG reductase-stimulated release of GSH from precipitated proteins. Furthermore, treatments that promoted accumulation of GSSG (50 microM diamide and 25 microM 1,3-bis(2-chloroethyl)-1-nitrosourea [BCNU]) inhibited Lucifer yellow dye transfer between myometrial cells. Findings that lindane induced GSH oxidation to GSSG with increased S-glutathionylation, together with the diamide and BCNU results, suggest that oxidation of GSH to GSSG is a component of the mechanism by which lindane inhibits myometrial gap junctions.
Collapse
Affiliation(s)
- Rita Loch Caruso
- Toxicology Program, Department of Environmental Health, University of Michigan, 1420 Washington Heights, Ann Arbor, Michigan 48109-2029, USA.
| | | | | | | |
Collapse
|
33
|
Nagarajan R, Eswaran H, Wilson JD, Murphy P, Lowery C, Preissl H. Analysis of uterine contractions: a dynamical approach. J Matern Fetal Neonatal Med 2003; 14:8-21. [PMID: 14563086 DOI: 10.1080/jmf.14.1.8.21] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The development of suitable techniques for quantifying mechanical and electrophysiological aspects of uterine contractions has been an active area of research. The uterus is a physiological system consisting of a large number of interacting muscle cells. The activity of these cells evolves with time, a trait characteristic of a dynamical system. While such complex physiological systems are non-linear by their very nature, whether this non-linearity is exhibited in the external recording is far from trivial. Traditional techniques such as spectral analysis have been used in the past, but these techniques implicitly assume that the process generating the contractions is linear and hence may be biased. In this tutorial review, a systematic approach using a hierarchy of surrogate algorithms is used to determine the nature of the process generating the contractions produced during labor. The results reveal that uterine contractions are probably generated by non-linear processes. The contraction segments were obtained through simultaneous recordings of the electrical and magnetic signals corresponding to the electrophysiological activity of the uterus and then analyzed. The electrical activity was recorded by placement of non-invasive electrodes onto the maternal abdomen and magnetic activity was recorded non-invasively using a superconducting quantum interference device (SQUID).
Collapse
Affiliation(s)
- R Nagarajan
- Center on Aging, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | | | | | | | | | | |
Collapse
|
34
|
Sakuma E, Herbert DC, Soji T. The effects of sex steroids on the formation of gap junctions between folliculo-stellate cells; a study in castrated male rats and ovariectomized female rats. ACTA ACUST UNITED AC 2003; 66:229-38. [PMID: 14527164 DOI: 10.1679/aohc.66.229] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We investigated the relationship between gap junction formation and the sex steroids testosterone, progesterone and 17beta-estradiol in the anterior pituitary glands of castrated male rats and ovariectomized female rats. Male and female 30-day-old Wistar-Imamichi strain rats were castrated or ovariectomized, and 30 days later they were subcutaneously injected with the above sex steroids. They were divided into six groups according to the injected materials: sesame oil (control), testosterone, progesterone, 17beta-estradiol, testosterone with 17beta-estradiol, and progesterone with 17beta-estradiol. Five rats from each group were sacrificed 1, 2, 3, 4 and 5 days after the injections, and the anterior pituitary glands were prepared for observation by transmission electron microscopy. We quantified the number of follicles and gap junctions and calculated the rate of occurrence of gap junctions as the ratio of the number of gap junctions existing between folliculo-stellate cells per intersected follicle profile in electron photomicrographs. The administration of testosterone to castrated male rats increased the rate of gap junctions between folliculo-stellate cells; however, progesterone and 17beta-estradiol did not affect the formation of gap junctions. The administration of progesterone to ovariectomized female rats increased the rate of gap junctions between folliculo-stellate cells; this progesterone effect was prevented by the simultaneous administration of 17beta-estradiol, which by itself did not affect the rate of gap junctions between folliculo-stellate cells. These observations indicate that the formation of gap junctions within the anterior pituitary gland is regulated differently by sex steroids in castrated male and ovariectomized female rats.
Collapse
Affiliation(s)
- Eisuke Sakuma
- Department of Functional Morphology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
| | | | | |
Collapse
|
35
|
Pierce BT, Calhoun BC, Adolphson KR, Lau AF, Pierce LM. Connexin 43 expression in normal versus dysfunctional labor. Am J Obstet Gynecol 2002; 186:504-11. [PMID: 11904615 DOI: 10.1067/mob.2002.121108] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE We sought to determine whether connexin 43 (Cx43), the major myometrial gap junction protein, is differentially expressed in normal versus dysfunctional labor. STUDY DESIGN Myometrial biopsies were obtained from 28 patients undergoing cesarean section and grouped into the following categories: (1) no labor, (2) dysfunctional labor, and (3) normal labor. Northern and Western analyses were performed to determine Cx43 messenger RNA (mRNA) and protein expression, respectively. Localization of Cx43 protein was determined by immunohistochemistry. RESULTS Labor was associated with increased Cx43 mRNA expression (P <.05). This association was not true for protein. There was no difference in mRNA or protein expression between patients with normal labor versus those with dysfunctional labor. The extent of Cx43 immunohistochemical staining was not significantly different among the groups (P >.05). CONCLUSION Dysfunctional labor is not associated with aberrant Cx43 mRNA or protein expression or with a reduction in immunodetectable Cx43 gap junctions.
Collapse
Affiliation(s)
- Brian T Pierce
- Division of Maternal-Fetal Medicine, the Department of Pathology, Madigan Army Medical Center, Fort Lewis, Wash, USA
| | | | | | | | | |
Collapse
|
36
|
Eswaran H, Wilson JD, Murphy P, Preissl H, Lowery CL. Application of wavelet transform to uterine electromyographic signals recorded using abdominal surface electrodes. J Matern Fetal Neonatal Med 2002; 11:158-66. [PMID: 12380670 DOI: 10.1080/jmf.11.3.158.166] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE The aim of this study was to explore the use of the wavelet transform technique to extract and display simultaneously the time, frequency and amplitude information corresponding to electromyographic (EMG) activity of the uterus during labor recorded using abdominal electrodes. METHODS Uterine EMG signals were recorded from patients in labor using three pairs of electrodes placed across the maternal abdomen. In all the patients uterine activity was also recorded either from an intrauterine pressure catheter (IUPC) or a tocodynamometer. The EMG signals were analyzed using spectral analysis and wavelet analysis. RESULTS Uterine EMG bursts corresponded with uterine activity measured with either the IUPC or the tocodynamometer. Using wavelet analysis a time-frequency-amplitude plot was obtained to separate out the frequency components relating to uterine EMG activity. CONCLUSION This study showed that the wavelet transform could be a useful tool to study the uterine EMG activity. Continued studies on frequency content, amplitude and origin of uterine EMG activity could be helpful in understanding uterine contraction.
Collapse
Affiliation(s)
- H Eswaran
- Graduate Institute of Technology, University of Arkansas at Little Rock, 72205, USA
| | | | | | | | | |
Collapse
|
37
|
Hjelm AM, Barchan K, Malmström A, Ekman-Ordeberg GE. Changes of the uterine proteoglycan distribution at term pregnancy and during labour. Eur J Obstet Gynecol Reprod Biol 2002; 100:146-51. [PMID: 11750954 DOI: 10.1016/s0301-2115(01)00476-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To characterise uterine proteoglycans and changes therein during pregnancy and labour. STUDY DESIGN Uterine samples were collected from 6 non-pregnant, 10 term-pregnant and from 10 women in active labour. The proteoglycans were extracted by 4M guanidine hydrochloride and precipitated with Alcian Blue. They were separated by electrophoresis and identified by Western blotting. RESULTS Decorin was the dominating proteoglycan and smaller amounts of biglycan was found. A considerable amount of heparan sulphate proteoglycans was also detected. Decorin and biglycan decreased by 40% until term. The amount of heparan sulphate proteoglycans increased by 46% during active labour. CONCLUSION Our data indicate that a considerable remodelling of the uterine connective tissue occurs during pregnancy and labour. The decrease of decorin and biglycan and the increase of heparan sulphate proteoglycans may be important for normal myometrial contractions during labour.
Collapse
Affiliation(s)
- Ann M Hjelm
- Department of Woman and Child Health/Division for Obstetrics and Gynecology, Karolinska Institute/Karolinska Hospital, P.O. Box 140, S-171 76, Stockholm, Sweden.
| | | | | | | |
Collapse
|
38
|
Hjelm A, Ekman-Ordeberg G, Barchan K, Malmström A. Identification of the major proteoglycans from human myometrium. Acta Obstet Gynecol Scand 2001; 80:1084-90. [PMID: 11846703 DOI: 10.1034/j.1600-0412.2001.801202.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND During pregnancy and parturition a remodeling within the extracellular matrix of the cervix and the corpus uteri occurs, which is of fundamental importance to a normal labor. The aim of this study is to identify the major proteoglycans in corpus uteri of non-pregnant subjects. METHODS From human uterine tissue proteoglycans were extracted and purified using CsCl-density gradient centrifugation, gel and ion-exchange chromatography. The proteoglycans were quantified and identified by Alcian Blue before and after ABC-digestion and by Western blotting. RESULTS The results showed that the corpus uteri contains a substantial amount of proteoglycans, 1.825 microg/mg wet weight. Decorin is dominating, constituting 63% of the total amount of proteoglycans. Heparan sulphate proteoglycans accounted for 20% and biglycan for 16%. Less than 1% consisted of the large proteoglycan versican. CONCLUSIONS Further investigations must be performed to provide more information of the biological role of the proteoglycans in the uterus, especially during labor, by the presence of heparan sulphate proteoglycans and the minute presence of versican which indicate that the proteoglycan composition and organization is different to that of the cervix.
Collapse
Affiliation(s)
- A Hjelm
- Department of Woman and Child Health, Division for Obstetrics and Gynecology, Karolinska Institute/Karolinska Hospital, Stockholm, Sweden
| | | | | | | |
Collapse
|
39
|
|
40
|
Meda P, Spray DC. Gap junction function. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1569-2558(00)30008-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
|
41
|
McKillen K, Thornton S, Taylor CW. Oxytocin increases the [Ca2+]i sensitivity of human myometrium during the falling phase of phasic contractions. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:E345-51. [PMID: 9950795 DOI: 10.1152/ajpendo.1999.276.2.e345] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxytocin is commonly used to induce or augment labor, but its mode of action is uncertain. To address the issue, isometric tension and the intracellular free Ca2+ concentration ([Ca2+]i) were simultaneously recorded from isolated strips of pregnant human myometrium loaded with fura 2. The changes in [Ca2+]i and tension during phasic contractions were indistinguishable in myometrium taken before or after the onset of labor, enabling samples to be pooled. Oxytocin (10 nM) had no effect on basal [Ca2+]i or tension, but it increased both the [Ca2+]i and the tension recorded during phasic contractions. Analysis of the [Ca2+]i-tension relationship revealed that during the falling (relaxation) phase of the contractile response, oxytocin increased the tension recorded at each [Ca2+]i. By manipulating extracellular Ca2+ during phasic contractions, it was possible to ensure that the [Ca2+]i signals were similar in the presence and absence of oxytocin, yet oxytocin still improved the [Ca2+]i-tension relationship. We conclude that 10 nM oxytocin increases the [Ca2+]i sensitivity of the contractile proteins only after a contraction has begun, possibly by causing inhibition of myosin light chain phosphatase.
Collapse
Affiliation(s)
- K McKillen
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1QJ, United Kingdom
| | | | | |
Collapse
|
42
|
Yapar EG, Senöz S, Urkütür M, Batioglu S, Gökmen O. Second trimester pregnancy termination including fetal death: comparison of five different methods. Eur J Obstet Gynecol Reprod Biol 1996; 69:97-102. [PMID: 8902440 DOI: 10.1016/0301-2115(95)02548-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To compare the efficacy of methods for second trimester pregnancy termination. METHODS A prospective randomized study of women undergoing pregnancy termination between 14 and 28 weeks gestation. Three hundred and forty patients with poor cervical condition (Bishop score < or = 4) in whom one of five termination methods were used were assessed: (i) extraamniotic administration of ethacridine lactate (82 patients); (ii) intracervical prostaglandin (PG) E2 gel (100 patients); (iii) intravenous infusion of concentrated oxytocin (36 patients); (iv) vaginal misoprostol (49 patients); and (v) balloon insertion (73 patients). Oxytocin infusion was used in all but concentrated oxytocin group to augment labor, when necessary. Patients in whom effective uterine contractions and cervical dilatation was not obtained within 48 h with the primary termination method were registered as failures. RESULTS The efficacy of each method were evaluated in terms of abortion within time. Abortion within 48 h were achieved in 98.8% (81/82) of the patients in ethacridine group; 97.3% (35/36) of the patients in concentrated oxytocin group; 90.0% (90/100) of the patients in PGE2 group; 97.2% (71/73) of the patients in balloon group; 77.5% (38/49) of the patients in misoprostol group (P = 0.000, P < 0.01, Wilcoxon (Gehan) statistic). The overall median induction-abortion interval +/- S.D. (in h) in each group were as follows: ethacridine lactate: 15.7 +/- 9.6, PGE2 gel: 20.0 +/- 14.5, concentrated oxytocin: 12.2 +/- 14.4, misoprostol: 24.0 +/- 22.2, balloon: 16.0 +/- 15.4 (one way ANOVA, P = 0.003, P < 0.01). CONCLUSION In comparison with the five methods, the use of extraamniotic ethacridine, intravenous concentrated oxytocin, and balloon was found to provide more effective treatment than intracervical PGE2 and misoprostol in terms of achievement of abortion within 24 and 48 h.
Collapse
Affiliation(s)
- E G Yapar
- Doctor Zekai Tahir Burak Women's Hospital, Department of Obstetrics and Gynecology, Ankara, Turkey
| | | | | | | | | |
Collapse
|
43
|
McGregor JA, Jackson GM, Lachelin GC, Goodwin TM, Artal R, Hastings C, Dullien V. Salivary estriol as risk assessment for preterm labor: a prospective trial. Am J Obstet Gynecol 1995; 173:1337-42. [PMID: 7485350 DOI: 10.1016/0002-9378(95)91383-1] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE Increased understanding of human parturition allows for novel approaches to (1) identification of women at increased risk for preterm birth and (2) development and controlled testing of etiology-based strategies to prevent preterm birth. STUDY DESIGN Five hundred forty-two women were enrolled at five study sites in a prospective evaluation of salivary estriol in samples obtained weekly beginning at 22 weeks' gestation (Salest, Biex, Inc., Boulder, Colo.). Estriol concentrations were determined with a well-characterized enzyme-linked immunoassay. Women adjudged at either high risk or low risk for prematurity were evaluated through to delivery. RESULTS A total of 267 women submitted serial samples that were analyzed; 241 women with singleton pregnancies submitted sufficient samples. Twenty-three women with singleton fetuses went into idiopathic preterm labor (without prior rupture of membranes) and were delivered preterm (mean 35 weeks' gestation); 182 were delivered at term (> or = 37 weeks' gestation). Mean (geometric) estriol concentrations were higher from 24 to 34 weeks in women with singleton pregnancies delivering preterm (p < 0.05). A surge in estriol concentrations occurred approximately 3 weeks before the onset of labor in both women delivering at term and those delivering preterm. This increase occurred approximately 4 weeks earlier in women delivered preterm versus term. Receiver-operator curve analyses showed that exceeding a 2.3 ng/ml saliva estriol level was associated with occurrence of preterm labor (71% sensitivity, 77% specificity, 23% false-positive rate). CONCLUSION Detection of an early estriol surge or increased level (> or = 2.3 ng/ml) may be clinically helpful in identifying women at elevated risk for preterm labor and birth, allowing for evaluation of biologically based interventions in controlled trials.
Collapse
Affiliation(s)
- J A McGregor
- Department of Obstretics and Gynecology, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | | | | | |
Collapse
|
44
|
Magann EF, Perry KG, Dockery JR, Bass JD, Chauhan SP, Morrison JC. Cervical ripening before medical induction of labor: a comparison of prostaglandin E2, estradiol, and oxytocin. Am J Obstet Gynecol 1995; 172:1702-6; discussion 1704-8. [PMID: 7778622 DOI: 10.1016/0002-9378(95)91401-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Our purpose was to evaluate the effectiveness of oxytocin, prostaglandin E2 intracervical gel, and estradiol cream for ripening the very unfavorable cervix in patients requiring induction of labor at term. STUDY DESIGN This prospective, randomized study was conducted in a population of women with a very unfavorable cervix (Bishop score < 4) requiring induction of labor. The patients received prostaglandin E2 gel (0.5 mg) intracervically (three doses 6 hours apart), 4 mg estradiol cream in the anterior fornix of the vagina (three doses 6 hours apart), or oxytocin at induction per protocol with an infusion pump. RESULTS Ninety-nine women were recruited into this trial and evenly distributed among the three groups. The demographics of maternal age, race, parity, gestational age, initial Bishop score, and indication for induction were similar among the groups. The incidence of cesarean deliveries was similar in the three groups with approximately 59% of pregnancies delivered abdominally. For patients undergoing abdominal delivery the maximum cervical dilatation among the oxytocin, estradiol, and prostaglandin E2 groups was similar (3.90 +/- 3.02 cm, 3.63 +/- 2.79 cm, and 4.65 +/- 2.78 cm, respectively; p > 0.05). For all patients birth weight and Apgar scores at 1 and 5 minutes were comparable across all regimens (p > 0.05). In the subset of patients delivered vaginally patients receiving oxytocin for cervical ripening had the greatest improvement in Bishop score over baseline (p = 0.023) with an improvement of 7.08 +/- 2.42. CONCLUSION No differences were detected among prostaglandin E2 gel, estrogen, and oxytocin in relation to cervical ripening in patients with an unfavorable cervix at term who require an induction of labor. Patients with a very unfavorable cervix at term who require delivery may benefit from serial ripening and inductions.
Collapse
Affiliation(s)
- E F Magann
- Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson 39216-4505, USA
| | | | | | | | | | | |
Collapse
|
45
|
Garfield RE, Ali M, Yallampalli C, Izumi H. Role of gap junctions and nitric oxide in control of myometrial contractility. Semin Perinatol 1995; 19:41-51. [PMID: 7754410 DOI: 10.1016/s0146-0005(95)80046-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- R E Garfield
- Department of Obstetrics and Gynecology, University of Texas Medical Branch Galveston 77555-1062, USA
| | | | | | | |
Collapse
|
46
|
Cunze T, Rath W, Osmers R, Martin M, Warneke G, Kuhn W. Magnesium and calcium concentration in the pregnant and non-pregnant myometrium. Int J Gynaecol Obstet 1995; 48:9-13. [PMID: 7698390 DOI: 10.1016/0020-7292(94)02217-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVES To investigate the effect of labor on the magnesium and calcium concentrations in the human myometrium and to compare them with the concentrations in the non-pregnant uterus. METHOD Samples of the isthmic part of the uterus were taken from 42 patients not in labor, 31 patients in regular labor during a cesarean section, and 37 premenopausal patients on whom a hysterectomy was performed. RESULTS (i) The magnesium concentration dropped significantly during labor; (ii) the calcium concentration in the tissue showed no significant changes during labor; (iii) the magnesium and calcium concentrations were significantly higher during pregnancy; (iv) the distribution of electrolytes in the myometrium differed significantly in the corpus, isthmus and cervix uteri. CONCLUSIONS The electrolyte concentration in the myometrium depends on the place of removal. A low magnesium concentration in the pregnant human myometrium could be a cause of premature labor.
Collapse
Affiliation(s)
- T Cunze
- Department of Gynecology and Obstetrics, University of Göttingen, Germany
| | | | | | | | | | | |
Collapse
|
47
|
Affiliation(s)
- R Romero
- Department of Obstetrics and Gynecology, Wayne State University, Hutzel Hospital, Detroit, Michigan 48201
| | | | | | | | | | | |
Collapse
|
48
|
Chow L, Lye SJ. Expression of the gap junction protein connexin-43 is increased in the human myometrium toward term and with the onset of labor. Am J Obstet Gynecol 1994; 170:788-95. [PMID: 8141203 DOI: 10.1016/s0002-9378(94)70284-5] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES Our aim was to determine the temporal pattern of expression of transcripts encoding the myometrial gap junction protein connexin-43 in the human myometrium during late pregnancy and with the onset of labor. We also correlated these data with levels of total connexin-43 protein and the appearance of gap junctions within the myometrial cell membrane. STUDY DESIGN Myometrial tissue was collected during cesarean section from 27 women between 37 and 41 weeks of gestation not in labor and from 7 women between 39 and 41 weeks during active labor. The levels of connexin-43 messenger ribonucleic acid and protein were estimated by Northern and Western analysis, respectively. The appearance of gap junctions between myometrial cells was assessed by immunofluorescence of histologic sections of myometrium from these women. RESULTS Levels of connexin-43 messenger ribonucleic acid in myometrial tissue collected from women not in labor increased (p < 0.01) between 37 and 40 weeks' gestation with a further significant increase occurring during labor (p < 0.05). The level of connexin-43 protein decreased (p < 0.05) during late pregnancy and was not increased during labor although gap junctions (which were not present during pregnancy) did appear in the myometrial cell membrane during labor. CONCLUSIONS These data suggest that the mechanisms responsible for the increased myometrial cell-cell communication necessary for the development of effective labor contractions likely involves regulation at the level of both messenger ribonucleic acid and gap junction formation in the cell membrane.
Collapse
Affiliation(s)
- L Chow
- Division of Perinatology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | | |
Collapse
|
49
|
Devedeux D, Marque C, Mansour S, Germain G, Duchêne J. Uterine electromyography: a critical review. Am J Obstet Gynecol 1993; 169:1636-53. [PMID: 8267082 DOI: 10.1016/0002-9378(93)90456-s] [Citation(s) in RCA: 243] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
On the basis of a literature review, this work summarizes uterine animal and human electromyographic information obtained at cellular, myometrial, and abdominal levels during gestation and parturition. We show that both internal and external electromyograms occur in phase with intrauterine pressure increase and exhibit similar spectra, including a slow wave (0.01 < frequency < 0.03 Hz) probably because of mechanical artifacts and a fast wave whose frequency content can be subdivided into a low-frequency band always present in every contraction and a high-frequency band related to efficient parturition contractions. Application of classic spectral techniques to electromyogram envelopes has identified group propagation but not pacemaker areas. However, no time delay or classic propagation has been demonstrated by applying the same spectral techniques to the electromyogram itself, probably because of the nonlinearity and three-dimensional nature of the propagating process.
Collapse
Affiliation(s)
- D Devedeux
- Unité de Recherche Associée, Centre National de Recherche Scientifique 858, Université de Technologie de Compiègne, France
| | | | | | | | | |
Collapse
|
50
|
Pettibone DJ, Clineschmidt BV, Guidotti MT, Lis EV, Reiss DR, Woyden CJ, Bock MG, Evans BE, Freidinger RM, Hobbs DW, Veber DF, Williams PD, Chiu SHL, Thompson KL, Schorn TW, Siegl PKS, Kaufman MJ, Cukierski MA, Haluska GJ, Cook MJ, Novy MJ. L-368,899, a potent orally active oxytocin antagonist for potential use in preterm labor. Drug Dev Res 1993. [DOI: 10.1002/ddr.430300305] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|