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Fang S, Shi L, Vink JSY, Feltovich H, Hall TJ, Myers KM. Equilibrium Mechanical Properties of the Nonhuman Primate Cervix. J Biomech Eng 2024; 146:081001. [PMID: 38270929 PMCID: PMC10983698 DOI: 10.1115/1.4064558] [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: 11/30/2022] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 01/26/2024]
Abstract
Cervical remodeling is critical for a healthy pregnancy. Premature tissue changes can lead to preterm birth (PTB), and the absence of remodeling can lead to post-term birth, causing significant morbidity. Comprehensive characterization of cervical material properties is necessary to uncover the mechanisms behind abnormal cervical softening. Quantifying cervical material properties during gestation is challenging in humans. Thus, a nonhuman primate (NHP) model is employed for this study. In this study, cervical tissue samples were collected from Rhesus macaques before pregnancy and at three gestational time points. Indentation and tension mechanical tests were conducted, coupled with digital image correlation (DIC), constitutive material modeling, and inverse finite element analysis (IFEA) to characterize the equilibrium material response of the macaque cervix during pregnancy. Results show, as gestation progresses: (1) the cervical fiber network becomes more extensible (nonpregnant versus pregnant locking stretch: 2.03 ± 1.09 versus 2.99 ± 1.39) and less stiff (nonpregnant versus pregnant initial stiffness: 272 ± 252 kPa versus 43 ± 43 kPa); (2) the ground substance compressibility does not change much (nonpregnant versus pregnant bulk modulus: 1.37 ± 0.82 kPa versus 2.81 ± 2.81 kPa); (3) fiber network dispersion increases, moving from aligned to randomly oriented (nonpregnant versus pregnant concentration coefficient: 1.03 ± 0.46 versus 0.50 ± 0.20); and (4) the largest change in fiber stiffness and dispersion happen during the second trimester. These results, for the first time, reveal the remodeling process of a nonhuman primate cervix and its distinct regimes throughout the entire pregnancy.
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Affiliation(s)
- Shuyang Fang
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Lei Shi
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Joy-Sarah Y. Vink
- Department of Obstetrics and Gynecology, Columbia University, New York, NY 10027
| | - Helen Feltovich
- Department of Maternal Fetal Medicine, Intermountain Healthcare, Park City, UT 84060
| | - Timothy J. Hall
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI 53706
| | - Kristin M. Myers
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
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Vedika R, Sharma P, Reddy A. Signature precursor and mature microRNAs in cervical ripening during gestational diabetes mellitus lead to pre-term labor and other impediments in future. J Diabetes Metab Disord 2023; 22:945-965. [PMID: 37975145 PMCID: PMC10638342 DOI: 10.1007/s40200-023-01232-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/29/2023] [Indexed: 11/19/2023]
Abstract
Gestational diabetes mellitus (GDM) is a pathological condition in which the placenta releases a hormone called human placental lactogen that prevents maternal insulin uptake. GDM is characterised by varying degrees of carbohydrate intolerance and is first identified during pregnancy. Around 5-17% of pregnancies are GDM pregnancies. Older or obese women have a higher risk of developing GDM during gestation. Hyperglycemia is a classic manifestation of GDM and leads to alterations in eNOS and iNOS expression and subsequently causes ROS and RNS overproduction. ROS and RNS play an important role in maintaining normal physiology, when present in low concentrations. Increased concentrations of ROS is harmful and can cause cellular and tissue damage. Oxidative stress is defined as an imbalance between pro-oxidant and antioxidant molecules that manifests due to hyperglycemia. miRNAs are short, non-coding RNAs that play a critical role in regulating gene expression. Studies have shown that the placenta expresses more than 500 miRNAs, which play a crucial role in trophoblast division, movement, and apoptosis. Latest research has revealed that hyperglycemic conditions and increased oxidative stress, characteristic of GDM, can lead to the dysregulation of miRNAs. The placenta also releases miRNAs into the maternal circulation. The secreted miRNAs are encapsulated in exosomes or vesicles. These exosomes interact with tissues and organs at distant sites, releasing their cargo intracellularly. This crosstalk between hyperglycemia, ROS and miRNA expression in GDM has detrimental effects on both foetal and maternal health. One of the complications of GDM is preterm labour. GDM induced iNOS expression has been implicated in cervical ripening, which in turn causes preterm birth. This article focuses on the speculations of oxidative and nitrative stress markers that lead to detrimental effects in GDM. We have also envisaged the role of non-coding miRNA interactions in regulating gene expression for oxidative damage. Graphical Abstract Holistic view of miRNA in GDM. I)(A) Placenta as a metabolic organ that provides the foetus with nutrients, oxygen and hormones to maintain pregnancy. Human placental lactogen (hPL) is one such hormone that is released into maternal circulation. hPL is known to induce insulin resistance. (B) ß-cell dysfunction leads to reduced glucose sensing and insulin production. Insulin resistance, a characteristic of GDM, exacerbates insulin ß cell dysfunction leading to maternal hyperglycemia. Hyperglycemia leads to increased ROS and RNS production through several mechanisms. Consequently, GDM is characterised by increased oxidative and nitrative stress.II)Exposure to maternal hyperglycemia causes increased ROS and RNS production in trophoblast cells. Oxidative stress caused by hyperglycemia may lead to eNOS uncoupling, causing eNOS to behave as a superoxide producing enzyme. iNOS expression in trophoblast cells leads to increased NO production. iNOS-derived NO reacts with ROS to produce RNS, thereby increasing nitrosative stress. Expression of antioxidant defences are reduced. Hyperglycemia and oxidative stress may alter the expression of some miRNAs. Some miRNAs are upregulated while others are downregulated. Some miRNAs are secreted into maternal circulation in the form of exosomes. Oxidative stress markers, nitrative stress markers and circulating miRNAs are found to be increased in maternal circulation.
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Affiliation(s)
- R. Vedika
- Animal cell culture laboratory, Department of Biotechnology, SRMIST, Kattankulathur, Tamil Nadu India
| | - Priyanshy Sharma
- Animal cell culture laboratory, Department of Biotechnology, SRMIST, Kattankulathur, Tamil Nadu India
| | - Amala Reddy
- Animal cell culture laboratory, Department of Biotechnology, SRMIST, Kattankulathur, Tamil Nadu India
- Department of Biotechnology, SRMIST, Kattankulathur, Kancheepuram 603203 India
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Socha MW, Flis W, Wartęga M, Szambelan M, Pietrus M, Kazdepka-Ziemińska A. Raspberry Leaves and Extracts-Molecular Mechanism of Action and Its Effectiveness on Human Cervical Ripening and the Induction of Labor. Nutrients 2023; 15:3206. [PMID: 37513625 PMCID: PMC10383074 DOI: 10.3390/nu15143206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/13/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023] Open
Abstract
The gestational period is an incredibly stressful time for a pregnant woman. Pregnant patients constantly seek effective and reliable compounds in order to achieve a healthy labor. Nowadays, increasing numbers of women use herbal preparations and supplements during pregnancy. One of the most popular and most frequently chosen herbs during pregnancy is the raspberry leaf (Rubus idaeus). Raspberry extracts are allegedly associated with a positive effect on childbirth through the induction of uterine contractions, acceleration of the cervical ripening, and shortening of childbirth. The history of the consumption of raspberry leaves throughout pregnancy is vast. This review shows the current status of the use of raspberry leaves in pregnancy, emphasizing the effect on the cervix, and the safety profile of this herb. The majority of women apply raspberry leaves during pregnancy to induce and ease labor. However, it has not been possible to determine the exact effect of using raspberry extracts on the course of childbirth and the perinatal period. Additionally, it is unclear whether this herb has only positive effects. The currently available data indicate a weak effect of raspberry leaf extracts on labor induction and, at the same time, their possible negative impact on cervical ripening.
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Affiliation(s)
- Maciej W Socha
- Department of Perinatology, Gynecology and Gynecologic Oncology, Faculty of Health Sciences, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Łukasiewicza 1, 85-821 Bydgoszcz, Poland
- Department of Obstetrics and Gynecology, St. Adalbert's Hospital in Gdańsk, Copernicus Healthcare Entity, Jana Pawła II 50, 80-462 Gdańsk, Poland
| | - Wojciech Flis
- Department of Perinatology, Gynecology and Gynecologic Oncology, Faculty of Health Sciences, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Łukasiewicza 1, 85-821 Bydgoszcz, Poland
- Department of Obstetrics and Gynecology, St. Adalbert's Hospital in Gdańsk, Copernicus Healthcare Entity, Jana Pawła II 50, 80-462 Gdańsk, Poland
| | - Mateusz Wartęga
- Department of Pathophysiology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, M. Curie-Skłodowskiej 9, 85-094 Bydgoszcz, Poland
| | - Monika Szambelan
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, M. Curie-Skłodowskiej 9, 85-094 Bydgoszcz, Poland
| | - Miłosz Pietrus
- Department of Gynecology and Oncology, Jagiellonian University Medical College, 31-501 Kraków, Poland
| | - Anita Kazdepka-Ziemińska
- Department of Perinatology, Gynecology and Gynecologic Oncology, Faculty of Health Sciences, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Łukasiewicza 1, 85-821 Bydgoszcz, Poland
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Signaling Pathways Regulating Human Cervical Ripening in Preterm and Term Delivery. Cells 2022; 11:cells11223690. [PMID: 36429118 PMCID: PMC9688647 DOI: 10.3390/cells11223690] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/13/2022] [Accepted: 11/18/2022] [Indexed: 11/22/2022] Open
Abstract
At the end of gestation, the cervical tissue changes profoundly. As a result of these changes, the uterine cervix becomes soft and vulnerable to dilation. The process occurring in the cervical tissue can be described as cervical ripening. The ripening is a process derivative of enzymatic breakdown and inflammatory response. Therefore, it is apparent that cervical remodeling is a derivative of the reactions mediated by multiple factors such as hormones, prostaglandins, nitric oxide, and inflammatory cytokines. However, despite the research carried out over the years, the cellular pathways responsible for regulating this process are still poorly understood. A comprehensive understanding of the entire process of cervical ripening seems crucial in the context of labor induction. Greater knowledge could provide us with the means to help women who suffer from dysfunctional labor. The overall objective of this review is to present the current understanding of cervical ripening in terms of molecular regulation and cell signaling.
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Impact of Oxidative Stress on Molecular Mechanisms of Cervical Ripening in Pregnant Women. Int J Mol Sci 2022; 23:ijms232112780. [PMID: 36361572 PMCID: PMC9657514 DOI: 10.3390/ijms232112780] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/13/2022] [Accepted: 10/21/2022] [Indexed: 11/29/2022] Open
Abstract
Uterine cervix is one of the essential factors in labor and maintaining the proper course of pregnancy. During the last days of gestation, the cervix undergoes extensive changes manifested by transformation from a tight and rigid to one that is soft and able to dilate. These changes can be summarized as “cervical ripening”. Changes in the cervical tissue can be referred to as remodeling of the extracellular matrix. The entire process is the result of a close relationship between biochemical and molecular pathways, which is strictly controlled by inflammatory and endocrine factors. When the production of reactive oxygen species exceeds the antioxidant capacity, oxidative stress occurs. A physiologic increase of reactive oxygen species (ROS) and reactive nitrogen species (RNS) is observed through pregnancy. ROS play important roles as second messengers in many intracellular signaling cascades contributing to the course of gestation. This review considers their involvement in the cervical ripening process, emphasizing the molecular and biochemical pathways and the clinical implications.
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Lee N, Shi L, Colon Caraballo M, Nallasamy S, Mahendroo M, Iozzo RV, Myers K. Mechanical Response of Mouse Cervices Lacking Decorin and Biglycan During Pregnancy. J Biomech Eng 2022; 144:061009. [PMID: 35348624 PMCID: PMC9125869 DOI: 10.1115/1.4054199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/23/2022] [Indexed: 11/08/2022]
Abstract
Cervical remodeling is critical for a healthy pregnancy. The proper regulation of extracellular matrix (ECM) turnover leads to remodeling throughout gestation, transforming the tissue from a stiff material to a compliant, extensible, viscoelastic tissue prepared for delivery. Small leucine-rich proteoglycans (SLRPs) regulate structural fiber assembly in the cervical ECM and overall tissue material properties. To quantify the SLRPs' mechanical role in the cervix, whole cervix specimens from nonpregnant and late pregnant knockout mice of SLRPs, decorin and biglycan, were subjected to cyclic load-unload, ramp-hold, and load-to-failure mechanical tests. Further, a fiber composite material model, accounting for collagen fiber bundle waviness, was developed to describe the cervix's three-dimensional large deformation equilibrium behavior. In nonpregnant tissue, SLRP knockout cervices have the same equilibrium material properties as wild-type tissue. In contrast, the load-to-failure and ramp-hold tests reveal SLRPs impact rupture and time-dependent relaxation behavior. Loss of decorin in nonpregnant (NP) cervices results in inferior rupture properties. After extensive remodeling, cervical strength is similar between all genotypes, but the SLRP-deficient tissue has a diminished ability to dissipate stress during a ramp-hold. In mice with a combined loss of decorin and biglycan, the pregnant cervix loses its extensibility, compliance, and viscoelasticity. These results suggest that decorin and biglycan are necessary for crucial extensibility and viscoelastic material properties of a healthy, remodeled pregnant cervix.
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Affiliation(s)
- Nicole Lee
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Lei Shi
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Mariano Colon Caraballo
- Department of Obstetrics and Gynecology, Cecil H. and Ida Green Center for Reproductive Biological Science, The University of Texas, Southwestern Medical Center, Dallas, TX 75390
| | - Shanmugasundaram Nallasamy
- Department of Obstetrics and Gynecology, Cecil H. and Ida Green Center for Reproductive Biological Science, The University of Texas, Southwestern Medical Center, Dallas, TX 75390
| | - Mala Mahendroo
- Department of Obstetrics and Gynecology, Cecil H. and Ida Green Center for Reproductive Biological Science, The University of Texas, Southwestern Medical Center, Dallas, TX 75390
| | - Renato V. Iozzo
- Department of Pathology, Anatomy and Cell Biology and the Translational Cellular Oncology Program, Sidney Kimmel Cancer Center, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107
| | - Kristin Myers
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
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Barnum CE, Fey JL, Weiss SN, Barila G, Brown AG, Connizzo BK, Shetye SS, Elovitz MA, Soslowsky LJ. Tensile Mechanical Properties and Dynamic Collagen Fiber Re-Alignment of the Murine Cervix are Dramatically Altered Throughout Pregnancy. J Biomech Eng 2017; 139:2621587. [PMID: 28418563 DOI: 10.1115/1.4036473] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Indexed: 12/26/2022]
Abstract
The cervix is a unique organ able to dramatically change its shape and function by serving as a physical barrier for the growing fetus and then undergoing dramatic dilation allowing for delivery of a term infant. As a result, the cervix endures changing mechanical forces from the growing fetus. There is an emerging concept that the cervix may change or remodel "early" in many cases of spontaneous preterm birth (sPTB). However, the mechanical role of the cervix in both normal and preterm birth remains unclear. Therefore, the primary objective of this study was to determine the mechanical and structural responses of murine cervical tissue throughout a normal gestational time course. In this study, both tissue structural and material properties were determined via a quasi-static tensile load-to-failure test, while simultaneously obtaining dynamic collagen fiber re-alignment via cross-polarization imaging. This study demonstrated that the majority of the mechanical properties evaluated decreased at midgestation and not just at term, while collagen fiber re-alignment occurred earlier in the loading curve for cervices at term. This suggests that although structural changes in the cervix occur throughout gestation, the differences in material properties function in combination with collagen fiber re-alignment as mechanical precursors to regulate term gestation. This work lays a foundation for investigating cervical biomechanics and the role of the cervix in preterm birth.
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Affiliation(s)
- Carrie E Barnum
- McKay Orthopedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Jennifer L Fey
- McKay Orthopedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Stephanie N Weiss
- McKay Orthopedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Guillermo Barila
- Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Amy G Brown
- Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Brianne K Connizzo
- McKay Orthopedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104;Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Snehal S Shetye
- McKay Orthopedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Michal A Elovitz
- Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Louis J Soslowsky
- McKay Orthopedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104 e-mail:
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Thorne JT, Segal TR, Chang S, Jorge S, Segars JH, Leppert PC. Dynamic reciprocity between cells and their microenvironment in reproduction. Biol Reprod 2014; 92:25. [PMID: 25411389 DOI: 10.1095/biolreprod.114.121368] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Dynamic reciprocity (DR) refers to the ongoing, bidirectional interaction between cells and their microenvironment, specifically the extracellular matrix (ECM). The continuous remodeling of the ECM exerts mechanical force on cells and modifies biochemical mediators near the cell membrane, thereby initiating cell-signaling cascades that produce changes in gene expression and cell behavior. Cellular changes, in turn, affect the composition and organization of ECM components. These continuous interactions are the fundamental principle behind DR, and its critical role throughout development and adult tissue homeostasis has been extensively investigated. While DR in the mammary gland has been well described, we provide direct evidence that similar dynamic interactions occur in other areas of reproductive biology as well. In order to establish the importance of DR in the adaptive functioning of the female reproductive tract, we present our most current understanding of DR in reproductive tissues, exploring the mammary gland, ovary, and uterus. In addition to explaining normal physiological function, investigating DR may shed new light into pathologic processes that occur in these tissues and provide an exciting opportunity for novel therapeutic intervention.
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Affiliation(s)
- Jeffrey T Thorne
- Department of Obstetrics & Gynecology, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Thalia R Segal
- Department of Obstetrics & Gynecology, North Shore - Long Island Jewish Hospital, Manhasset, New York
| | - Sydney Chang
- Unit of Reproductive Endocrinology and Infertility, Eunice Kennedy Shriver National Institute of Child Health & Human Development, National Institutes of Health, Bethesda, Maryland Department of Obstetrics & Gynecology, Duke University School of Medicine, Durham, North Carolina
| | - Soledad Jorge
- Unit of Reproductive Endocrinology and Infertility, Eunice Kennedy Shriver National Institute of Child Health & Human Development, National Institutes of Health, Bethesda, Maryland Yale University School of Medicine, New Haven, Connecticut
| | - James H Segars
- Unit of Reproductive Endocrinology and Infertility, Eunice Kennedy Shriver National Institute of Child Health & Human Development, National Institutes of Health, Bethesda, Maryland
| | - Phyllis C Leppert
- Department of Obstetrics & Gynecology, Duke University School of Medicine, Durham, North Carolina
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Leppert PC. Tissue remodeling in the female reproductive tract--a complex process becomes more complex: the role of Hox genes. Biol Reprod 2012; 86:98. [PMID: 22302691 DOI: 10.1095/biolreprod.112.099283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Phyllis C Leppert
- Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, North Carolina 27710, USA.
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Hassan SS, Romero R, Tarca AL, Nhan-Chang CL, Vaisbuch E, Erez O, Mittal P, Kusanovic JP, Mazaki-Tovi S, Yeo L, Draghici S, Kim JS, Uldbjerg N, Kim CJ. The transcriptome of cervical ripening in human pregnancy before the onset of labor at term: identification of novel molecular functions involved in this process. J Matern Fetal Neonatal Med 2010; 22:1183-93. [PMID: 19883264 DOI: 10.3109/14767050903353216] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The aim of this study was to identify changes in the cervical transcriptome in the human uterine cervix as a function of ripening before the onset of labor. STUDY DESIGN Human cervical tissue was obtained from women at term not in labor with ripe (n = 11) and unripe (n = 11) cervices and profiled using Affymetrix GeneChip HGU133Plus2.0 arrays. Gene expression was analyzed using a moderated t-test (False Discovery Rate 5%). Gene ontology and pathway analysis were performed. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used for confirmation of selected differentially expressed genes. RESULTS (1) Ninety-one genes were differentially expressed between ripe and unripe groups. (2) Cervical ripening was associated with enrichment of specific biological processes (e.g. cell adhesion, regulation of anatomical structure), pathways and 11 molecular functions (e.g. extracelluar matrix (ECM)-structural constituent, protein binding, glycosaminoglycan binding). (3) qRT-PCR confirmed that 9 of 11 tested differentially expressed genes (determined by microarray) were upregulated in a ripe cervix (e.g. MYOCD, VCAN, THBS1, COL5A1). (4) Twenty-three additional genes related to ECM metabolism and adhesion molecules were differentially regulated (by qRT-PCR) in ripe cervices. CONCLUSION (1) This is the first description of the changes in the human cervical transcriptome with ripening before the onset of labor. (2) Biological processes, pathways and molecular functions were identified with the use of this unbiased approach. (3) In contrast to cervical dilation after term labor, inflammation-related genes did not emerge as differentially regulated with cervical ripening. (4) Myocardin was identified as a novel gene upregulated in human cervical ripening.
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Affiliation(s)
- Sonia S Hassan
- Department of Obstetrics and Gynecology, Wayne State University/Hutzel Women's Hospital, Detroit, MI 48201, USA.
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Mackay LB, Shi L, Maul H, Maner WL, Garfield RE. The effect of bilateral pelvic neurectomy on cervical ripening in pregnant rats. J Perinat Med 2010; 37:263-9. [PMID: 19196210 DOI: 10.1515/jpm.2009.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AIMS To determine the effect of bilateral pelvic neurectomy (BPN) on cervical ripening in pregnant rats by measuring cervical extensibility and changes in collagen cross-linkages. METHODS Timed-pregnant rats were randomly laparotomized on days 9 or 10 of gestation and the pelvic nerves were exposed and either bilaterally transected, or left intact in sham control animals. The rats were sacrificed on day 18 and the uterine cervices obtained. Cervical ripening was assessed by cervical resistance-to-stretch, light-induced autofluorescence (LIF) of cross-linked collagen, and collagen changes analyzed by picrosirius polarization microscopy. RESULTS Measurements of extensibility and collagen cross-linkages indicated that after BPN the cervix was significantly more ripened than the cervix from sham control animals. CONCLUSION BPN stimulates cervical ripening instead of inhibiting this event as previously proposed. Further studies in this area could be critical for developing treatments for dystocia, preterm labor, and cervical insufficiency.
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Affiliation(s)
- Lynette B Mackay
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas, USA
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Mowa CN, Li T, Jesmin S, Folkesson HG, Usip SE, Papka RE, Hou G. Delineation of VEGF-regulated genes and functions in the cervix of pregnant rodents by DNA microarray analysis. Reprod Biol Endocrinol 2008; 6:64. [PMID: 19087268 PMCID: PMC2628666 DOI: 10.1186/1477-7827-6-64] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Accepted: 12/16/2008] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND VEGF-regulated genes in the cervices of pregnant and non-pregnant rodents (rats and mice) were delineated by DNA microarray and Real Time PCR, after locally altering levels of or action of VEGF using VEGF agents, namely siRNA, VEGF receptor antagonist and mouse VEGF recombinant protein. METHODS Tissues were analyzed by genome-wide DNA microarray analysis, Real-time and gel-based PCR, and SEM, to decipher VEGF function during cervical remodeling. Data were analyzed by EASE score (microarray) and ANOVA (Real Time PCR) followed by Scheffe's F-test for multiple comparisons. RESULTS Of the 30,000 genes analyzed, about 4,200 genes were altered in expression by VEGF, i.e., expression of about 2,400 and 1,700 genes were down- and up-regulated, respectively. Based on EASE score, i.e., grouping of genes according to their biological process, cell component and molecular functions, a number of vascular- and non-vascular-related processes were found to be regulated by VEGF in the cervix, including immune response (including inflammatory), cell proliferation, protein kinase activity, and cell adhesion molecule activity. Of interest, mRNA levels of a select group of genes, known to or with potential to influence cervical remodeling were altered. For example, real time PCR analysis showed that levels of VCAM-1, a key molecule in leukocyte recruitment, endothelial adhesion, and subsequent trans-endothelial migration, were elevated about 10 folds by VEGF. Further, VEGF agents also altered mRNA levels of decorin, which is involved in cervical collagen fibrillogenesis, and expression of eNO, PLC and PKC mRNA, critical downstream mediators of VEGF. Of note, we show that VEGF may regulate cervical epithelial proliferation, as revealed by SEM. CONCLUSION These data are important in that they shed new insights in VEGF's possible roles and mechanisms in cervical events near-term, including cervical remodeling.
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Affiliation(s)
- Chishimba N Mowa
- Appalachian State University, Department of Biology, Rankin Science North Building N219, 572 River Street, Boone, NC 28608, USA
| | - Tianbo Li
- Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Departments of Integrative Medical Sciences, 4209 St. Rt. 44, PO Box 95, Rootstown, Ohio 44272, USA
| | - Subrina Jesmin
- Department of Gene Diagnostics and Therapeutics, Research Institute, International Medical Center of Japan, Tokyo, 1-21-1 Toyama, Shinjuku-ku, 162-8655, Tokyo, Japan
| | - Hans G Folkesson
- Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Departments of Integrative Medical Sciences, 4209 St. Rt. 44, PO Box 95, Rootstown, Ohio 44272, USA
| | - Sharon E Usip
- Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Departments of Neurobiology and Anatomy, 4209 St. Rt. 44, PO Box 95, Rootstown, Ohio 44272, USA
| | - Raymond E Papka
- Northeastern Ohio Universities Colleges of Medicine and Pharmacy, Departments of Neurobiology and Anatomy, 4209 St. Rt. 44, PO Box 95, Rootstown, Ohio 44272, USA
| | - Guichuan Hou
- Appalachian State University, Department of Biology, Rankin Science North Building N219, 572 River Street, Boone, NC 28608, USA
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Baños A, Wolf M, Grawe C, Stahel M, Haensse D, Fink D, Hornung R. Frequency domain near-infrared spectroscopy of the uterine cervix during cervical ripening. Lasers Surg Med 2008; 39:641-6. [PMID: 17886282 DOI: 10.1002/lsm.20542] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor has a substantial inter- and intraobserver variability. We used frequency domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during drug-induced cervical ripening. METHODS Ten volunteers scheduled for abortion were examined. Optical properties of the uterine cervix were measured and physiological parameters were calculated prior to and after induction of cervical ripening using topical misoprostol. Mean relative changes, +/-standard error of the mean as well as statistical significance using the t-test were calculated for oxy- and deoxyhemoglobin, total hemoglobin, oxygen-saturation, and water. The wavelength-dependent decrease of scattering (scatter power) was calculated by an exponential fit and tested with the Wilcoxon test. RESULTS Misoprostol induced a decrease in total hemoglobin of 21 +/- 6% (P < 0.05), a decrease in oxyhemoglobin of 22 +/- 6% (P < 0.05), a decrease in deoxyhemoglobin of 16 +/- 11% and an increase of 36 +/- 8% (P < 0.005) in water content. The scatter power was significantly lower (P < 0.05) after cervical ripening. CONCLUSION Our results show that FD-NIRS is a promising diagnostic tool to detect changes in cervical concentrations of hemoglobin and water. A severe tissue edema, probably due to a hormone-induced inflammatory process, seems to be important for cervical ripening. The reduction in total hemoglobin is likely to be a consequence of the increased water content of the tissue resulting in a dramatic increase of the distance between vessels. We propose this technology to assess the cervical ripening and eventually to predict preterm labor.
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Affiliation(s)
- Ana Baños
- Department of Obstetrics and Gynecology, University Hospital Zurich, Zurich, Switzerland
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14
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Kolarovszki-Sipiczki Z, Gáspár R, Ducza E, Páldy E, Benyhe S, Borsodi A, Falkay G. EFFECT OF ?1-ADRENOCEPTOR SUBTYPE-SELECTIVE INVERSE AGONISTS ON NON-PREGNANT AND LATE-PREGNANT CERVICAL RESISTANCE IN VITRO IN THE RAT. Clin Exp Pharmacol Physiol 2007; 34:42-7. [PMID: 17201734 DOI: 10.1111/j.1440-1681.2007.04529.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1. The aim of the present study was to compare and elucidate the effects of alpha(1)-adrenoceptor (alpha(1)-AR) subtype-selective inverse agonists on non-pregnant and late-pregnant rat cervical tone. 2. Cervical resistance was investigated in in vitro stretching tests in the absence or presence of alpha(1)-AR subtype-selective inverse agonists (WB 4101, AH 11110A and BMY 7378; all at 10(-6) mol/L), whereas the mRNA levels and density of the alpha(1)-AR subtypes and the G-protein-activating effects of the inverse agonists were determined by reverse transcription-polymerase chain reaction, western blot and [(35)S]-GTPgammaS binding techniques, respectively. 3. The inverse agonists did not cause any change in resistance in non-pregnant and 18-day-pregnant samples. WB 4101 increased cervical resistance from Day 20, whereas AH 11110A had no effect and BMY 7378 exhibited such an action only on Day 21. Phenylephrine (10(-4) mol/L) had no effect on cervical resistance on Day 22. The mRNA levels and density of all alpha(1)-AR subtypes were increased on Day 18, but no further changes were observed after that. The [(35)S]-GTPgammaS binding studies revealed increased G-protein activation of alpha(1A)-AR and a moderate G-protein activation of alpha(1B)- and alpha(1D)-AR. The effect of WB 4101 to increase [(35)S]-GTPgammaS binding was blocked by pertussis toxin (50 ng/mL). Phenylephrine caused a slight and significant decrease in the amount of activated G-protein on Day 22. 4. The effects of inverse agonists on the alpha(1A)-AR can enhance cervical resistance in the late-pregnant rat in vitro. This action is mediated, at least in part, by a pertussis toxin-sensitive G(i)-protein. This effect of the alpha(1A)-AR inverse agonist WB 4101 may offer a new therapeutic target in the prevention of premature labour.
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Bullarbo M, Norström A, Andersch B, Ekerhovd E. Isosorbide mononitrate induces increased cervical expression of cyclooxygenase-2, but not of cyclooxygenase-1, at term. Eur J Obstet Gynecol Reprod Biol 2006; 130:160-4. [PMID: 16675095 DOI: 10.1016/j.ejogrb.2006.01.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 12/07/2005] [Accepted: 01/10/2006] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Prostaglandin and nitric oxide (NO) are both known to be involved in cervical ripening at term. The aim of the study was to investigate if NO has an effect on cervical expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), the two main isoenzymes involved in prostaglandin synthesis, and to localize these enzymes within the cervix. STUDY DESIGN Women with an unripe cervix scheduled for elective caesarean section at term were randomly selected to receive vaginally either the NO donor isosorbide mononitrate (IMN) or placebo 4h before surgery. At the operating theatre, cervical tissue specimens were obtained for immunoblotting and immunohistochemistry. RESULTS Increased expression of COX-2 was found in specimens exposed to IMN compared to specimens obtained from women in the placebo group. There was no difference in the expression of COX-1. Immunohistochemistry revealed similar localization of the two enzymes in treated and untreated women. CONCLUSIONS Vaginal administration of IMN induces increased cervical expression of COX-2, but not of COX-1. This pathway may be of importance in the process of cervical ripening at term.
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Affiliation(s)
- M Bullarbo
- Department of Obstetrics and Gynaecology, Sahlgrenska University Hospital, 41685 Gothenburg, Sweden.
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16
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Clark K, Ji H, Feltovich H, Janowski J, Carroll C, Chien EK. Mifepristone-induced cervical ripening: structural, biomechanical, and molecular events. Am J Obstet Gynecol 2006; 194:1391-8. [PMID: 16647925 DOI: 10.1016/j.ajog.2005.11.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 09/11/2005] [Accepted: 11/14/2005] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The purpose of this study was to assess the structural, biomechanical, and biochemical effects of mifepristone-induced progesterone withdrawal on the rat cervix to identify possible mechanisms by which mifepristone incites cervical ripening. STUDY DESIGN After the administration of mifepristone, cervical tensile strength was determined by the cervical creep method. With polarized light microscopy and transmission electron microscopy, collagen organization and microstructure were quantified. Matrix metalloproteinase expression was assessed by Western Blot and Real-time reverse transcriptase-polymerase chain reaction. RESULTS Mifepristone induced a decrease in cervical tensile strength at mid gestation that was associated with a decrease in collagen organization. Additionally, mifepristone led to collagen fragmentation with a significant decrease in fibril length and diameter, although fibril bundling remained unaffected. Matrix metalloproteinase-2 expression increased after the administration of mifepristone. CONCLUSION Mifepristone-induced cervical ripening is associated with collagen degradation, and the collagenase activity of matrix metalloproteinase-2 may play a role in this process.
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Affiliation(s)
- Kelley Clark
- Department of Obstetrics and Gynecology, University of Vermont, Burlington, VT 05401, USA.
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17
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Marx SG, Wentz MJ, Mackay LB, Schlembach D, Maul H, Fittkow C, Given R, Vedernikov Y, Saade GR, Garfield RE. Effects of progesterone on iNOS, COX-2, and collagen expression in the cervix. J Histochem Cytochem 2006; 54:623-39. [PMID: 16399999 DOI: 10.1369/jhc.5a6759.2006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
This study examines the relationship between inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in the control of cervical ripening and parturition under normal (normal term pregnancy) and abnormal (preterm labor and prolongation of pregnancy) conditions by (a) measuring changes in the collagen both visually and quantitatively, (b) localizing and characterizing iNOS and COX-2 under normal conditions, and (c) characterizing the changes in iNOS and COX-2 under abnormal conditions. Cervices are obtained from estrus and timed pregnant Sprague-Dawley rats (n=4-10 per group). Preterm labor is induced with Onapristone (3 mg/rat; progesterone antagonist) and the prolongation of pregnancy with progesterone (2.5 mg, twice daily). Collagen changes are measured and visualized with the picrosirius polarization method. RT-PCR is used to characterize the mRNA expression (p<0.05), and immunohistochemistry is used to localize the protein expression for iNOS and COX-2. The organization and birefringence of the collagen during pregnancy decreased and is supported by changes in the luminosity (p<0.001). The iNOS and COX-2 enzymes were localized in cervical smooth muscle, vascular smooth muscle, and epithelium. Under normal conditions, iNOS mRNA levels decreased as COX-2 mRNA levels increased demonstrating an inverse correlation (Spearman r = -0.497; p=0.00295). Onapristone stimulated preterm labor, increasing the iNOS and COX-2 mRNA (p<0.05). The increase demonstrated a positive correlation (Spearman r = 0.456; p=0.03). Progesterone prolonged pregnancy, decreasing the iNOS and COX-2 mRNA (p=0.036). In conclusion, there may be an interaction between the nitric oxide and prostaglandin pathways in cervical ripening and parturition.
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Affiliation(s)
- Stephen G Marx
- The University of Texas Medical Branch, Department of Obstetrics and Gynecology, Medical Research Bldg. 11.104, 301 University Boulevard, Galveston, Texas 77555-106, USA
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18
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Aalberts M, van Dissel-Emiliani FMF, van Tol HTA, Taverne MAM, Breeveld-Dwarkasing VNA. High iNOS mRNA and protein levels during early third trimester suggest a role for NO in prelabor cervical ripening in the bovine. Mol Reprod Dev 2006; 74:378-85. [PMID: 16967498 DOI: 10.1002/mrd.20546] [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] [Indexed: 11/11/2022]
Abstract
Nitric oxide (NO) plays a key role in the processes leading to cervical softening prior to labor. Inducible nitric oxide synthase (iNOS) contributes most to the increased production of NO during labor, as demonstrated in the rat cervix, or at term pregnancy in women. Changes in expression of iNOS during late gestation have not yet been studied longitudinally in any species, because repeatedly taking biopsies could not be performed. iNOS mRNA (n = 6) and protein expression (n = 3) in serial cervical biopsies of pregnant pluriparous cows taken around days 225, 250, and 275 of pregnancy and within 1.5 hr after calving (d225, d250, d275 and parturition biopsies, respectively) were measured using quantitative RT-PCR and Western blotting. iNOS mRNA expression decreased from the d225 biopsy onwards, differences being significant between the d250 and d275 (P < 0.05) and between the d275 and parturition biopsies (P < 0.05). iNOS protein expression decreased from d225 to d250 onwards. Immunohistochemical analysis of biopsies showed, besides positive staining in endothelium and epithelium, which remained unchanged at different time points, that iNOS expressing cells in the connective tissue cells of early biopsies were predominantly spindle shaped (mostly smooth muscle cells and some fibroblasts). In the parturition biopsies, iNOS reactivity was mainly found in mononuclear leucocytes. These results lead us to suggest that iNOS from spindle shaped cells is involved in prepartum cervical ripening, while iNOS in mononuclear inflammatory cells may be important for local tissue repair mechanisms during postpartum cervical involution.
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Affiliation(s)
- Marian Aalberts
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
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19
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Tekesin I, Wallwiener D, Schmidt S. The value of quantitative ultrasound tissue characterization of the cervix and rapid fetal fibronectin in predicting preterm delivery. J Perinat Med 2005; 33:383-91. [PMID: 16238532 DOI: 10.1515/jpm.2005.070] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To evaluate clinical risk factors, cervical fetal fibronectin (fFN), cervical length, and mean gray value assessment in predicting of preterm delivery (PTD) in patients with signs and/or symptoms of preterm labor (PTL). STUDY DESIGN One hundred and seventeen women with PTL between 24 and 34 weeks of gestation were included. Cervical swabs were tested for fFN using the rapid fFN assay. When 2-dimensional transvaginal ultrasound measurement of cervical length was completed, a region of interest (ROI) of constant size was defined in the midsection of the posterior wall, and the tissue-specific gray scale was determined. The end point were PTDs at <34 and <37 weeks of gestation. RESULTS In univariate analysis, the three strongest predictors of spontaneous preterm birth <34 weeks were positive fFN (relative risk [RR] 8.9; 95% confidence interval [CI] 2.6-30.1), cervical length < or =2.5 cm (RR 6.9; 95% CI 1.6-29.7), and a low mean gray value of < or =5.97 (RR 7.9; 95% CI 2.3-27.2). Predictors significantly associated with spontaneous PTD at less than 37 weeks of gestation included previous PTD in multiparas (RR 3.9; 95% CI 1.6-9.5), positive fFN (RR 7.6; 95% CI 3.8-15.3), cervical length < or =2.5 cm (RR 2.6; 95% CI 1.4-5.1) and a low gray scale value of < or =6.54 (RR 4.5; 95% CI 2.3-8.9). In the final regression models used to predict spontaneous PTD <34 weeks and <37 weeks of gestation, both a positive fetal fibronectin (odds ratio [OR] 13.4; 95% CI, 2.5-72.1, P=0.003 vs. OR, 17.3; 95% CI 4.9-61.8, P<0.001) and a low gray scale value (OR 6.3 95% CI 1.3-29.4, P=0.02 vs. OR, 7.1; 95% CI 2-25.2, P=0.003) remained powerful predictors. The RRs of spontaneous PTD <37 weeks has been analyzed by a combination of these significant parameters. Low mean gray value < or =6.54 and negative fFN had a 10.3-fold (95% CI 2-74.5) increased risk of spontaneous preterm birth at <37 weeks. Combination of positive fFN and normal gray level (>6.54), had a higher increase risk of PTD (RR 18.1; 95% CI 4.4-76.7). When both factors were positive, the RR increases to 24.8 (95% CI 6.2-98.7). CONCLUSIONS Combined use of rapid fFN and cervical gray value analysis improves the diagnostic efficiency and allows identification of women at risk for preterm delivery and in need for further prophylactic/therapeutic intervention.
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Affiliation(s)
- Ismail Tekesin
- Department of Gynecology and Obstetrics, University of Tuebingen, Germany.
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20
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Kemp B, Rath W, Winkler M, Reineke T, Beier HM, von Rango U. Is cervical dilatation during parturition at term associated with apoptosis? J Perinat Med 2005; 33:137-43. [PMID: 15843264 DOI: 10.1515/jpm.2005.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AIMS Cellular turnover may be involved in remodeling of the cervix during parturition. Therefore, the number and localization of apoptotic and proliferating cells during cervical dilatation at term were determined. METHODS Biopsy specimens from the lower uterine segment of 36 women undergoing cesarean section with a cervical dilatation of < 2 cm (n = 10), 2- < 4 cm (n = 9), 4-6 cm (n = 8), and > 6 cm (n = 9) were examined for nuclear fragmentation by the TUNEL assay, and for cell survival by the apoptosis-blocking bcl-2. Proliferation was marked by Ki-67, epithelial cells by cytokeratin and leukocytes by CD 45. For quantification of apoptotic and proliferating cells, eight random fields of each specimen stained for TUNEL or Ki-67 were blindly counted by two investigators. For statistical evaluation, 90% confidence intervals based on a Poisson distribution were used; groups with non-overlapping intervals were considered significantly different. RESULTS Apoptotic cells were found exclusively within the stromal compartment, while bcl-2 was expressed in epithelial cells and leukocytes. Proliferating cells were of stromal and epithelial origin. The number of apoptotic as well as proliferating cells ranged from 0 to 2 cells per high-power field (median number 0) in all groups. The confidence intervals were overlapping for all groups, showing no statistical difference between them. CONCLUSION Apoptosis does not seem to play a decisive role in the process of cervical dilatation during parturition at term.
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Affiliation(s)
- B Kemp
- Department of Obstetrics and Gynecology, University Hospital, Technical University, Aachen, Germany.
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21
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Abstract
Cervical competence is a key function in normal and abnormal labour. Remodelling of the cervical structure, by reorientation and changes in the integrity of collagen fibres by an alteration in the content of water, proteoglycans and hyaluronic acid, takes place before parturition. Such morphological changes have been associated with the activation of several biochemical pathways, sharing those of an apyretic, proinflammatory reaction, including the inducible isoform of the nitric oxide synthase (NOS). Nitric oxide (NO) is believed to be the final mediator in the mechanisms that allow ripening of the cervix. A reduction of NO activity in the uterus, together with its activation in the cervix, is hypothesised to be a facilitating factor in human parturition. The local application of NO donors in both animals and humans induces ultrastructural changes similar to those occurring during physiological cervical maturation. NO donors have proven to be clinically effective in facilitating first trimester dilation and curettage. Preliminary data also suggest that in women presenting with threatening preterm labour, there is increased activity of NO in the cervix, which is associated with shortening. A complex interaction between cytokines, prostaglandins (PGs) and NO is the key biochemical pathway accounting for the preterm ripening of the cervix.
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Affiliation(s)
- Fabio Facchinetti
- Mother-Infant Department, University of Modena and Reggio Emilia, Via del Pozzo 71, 41100 Modena, Italy
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22
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Gáspár R, Kolarovszki-Sipiczki Z, Ducza E, Páldy E, Benyhe S, Borsodi A, Falkay G. Terbutaline increases the cervical resistance of the pregnant rat in vitro. Naunyn Schmiedebergs Arch Pharmacol 2005; 371:61-71. [PMID: 15645294 DOI: 10.1007/s00210-004-1010-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Accepted: 11/19/2004] [Indexed: 11/28/2022]
Abstract
Cervical ripening is a crucial process leading to delivery. Early dilation of the pregnant cervix can contribute to premature labour. The maturity of the cervix can be characterized by its resistance to mechanical stretching. Although a number of compounds are considered to increase cervical resistance (e.g., progesterone, nitric oxide synthase inhibitors and nonsteroidal anti-inflammatory drugs), none of them seem to be safe for clinical application. Other compounds, such as beta(2)-adrenergic receptor (beta(2)-AR) agonists, have been used for several decades to stop premature myometrium contractions, but their cervical action has never been investigated. The aim of this study was to detect the effects of the beta(2)-AR agonist terbutaline on nonpregnant and late-pregnant (day 18, 20, 21 or 22) cervices isolated from Sprague-Dawley rats. Cervical resistance was measured by means of a mechanical stretching test in vitro, the beta(2)-AR density was determined by Western blot analysis, the beta(2)-AR mRNA was determined by RT-PCR, while the G-protein activation following cervical beta(2)-AR stimulation with terbutaline was evaluated via a [(35)S]GTPgammaS binding assay. Terbutaline at 10(-6) M increased the cervical resistance of the late-pregnant samples in vitro from day 18 to day 22, but did not alter the resistance of the nonpregnant samples. This cervical resistance-increasing effect was concentration dependent and antagonized with propranolol on day 21. Terbutaline was ineffective on cervical samples when gradual stretching was omitted. RT-PCR and Western blot studies revealed increased beta(2)-AR mRNA and beta(2)-AR levels respectively on day 18 of pregnancy compared with the nonpregnant cervix, but no further changes were detected up to the end of pregnancy. The [(35)S]GTPgammaS binding assay demonstrated a decreased G-protein activation on the days of pregnancy investigated, but no activation was found in the nonpregnant samples. The degree of decrease in G-protein activation by terbutaline was in harmony with its cervical resistance-increasing action. On day 21, the G-protein activation-decreasing effect of terbutaline was antagonized with propranolol. We presume that the cervical resistance-increasing effect of terbutaline is a consequence of its G-protein activation-decreasing property via beta(2)-ARs, which finally leads to an increased muscle resistance against mechanical stretching. This action of terbutaline seems unique among the smooth muscles, and may open up a new perspective in the prevention of premature labour. Clinical experience indicates that beta(2)-AR agonists will not be sufficient to stop the overall process, but their combination with more potent inhibitors of uterine contractions may be of clinical benefit.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Biomechanical Phenomena
- Blotting, Western
- Cervical Ripening/drug effects
- Dose-Response Relationship, Drug
- Female
- GTP-Binding Proteins/physiology
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Labor, Obstetric/physiology
- Male
- Muscle Tonus/drug effects
- Muscle, Smooth/drug effects
- Pregnancy
- Propranolol/pharmacology
- RNA, Messenger/biosynthesis
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, beta-2/biosynthesis
- Receptors, Adrenergic, beta-2/drug effects
- Reverse Transcriptase Polymerase Chain Reaction
- Terbutaline/pharmacology
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Affiliation(s)
- Róbert Gáspár
- Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
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23
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Lurie S, Sadan O, Ben Aroya Z, Glezerman M. Atosiban treatment for uterine hyperactivity during active labor: a pilot study. J Perinat Med 2004; 32:137-9. [PMID: 15085889 DOI: 10.1515/jpm.2004.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE A preliminary assessment of the ability of Atosiban to alleviate uterine hyperactivity during active labor. METHODS Fifteen consecutive women with uterine hyperactivity during active labor were included in this prospective observational study. Atosiban was given as a single or repeated intravenous bolus dose (6.75 mg in 0.9 mL NaCl solution) if hyperactivity was not alleviated within 5 minutes with "intrauterine resuscitation" measures. RESULTS Alleviation of uterine activity was achieved in 14 out of 15 cases and was almost immediate in the responders. Alleviation of accompanying fetal heart rate abnormalities was achieved in 13 out of 14 cases. In 7 of 15 women a cesarean section was performed, eventually. Atosiban was well tolerated by all women and no side effects were noted. There were no 5 minutes Apgar scores of less than 7. There were no cases of neonatal asphyxia or neonatal mortality. CONCLUSION Atosiban may be an effective treatment of uterine hyperactivity during active labor.
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Affiliation(s)
- Samuel Lurie
- Department of Obstetrics and Gynecology, Edith Wolfson Medical Center, Holon, Israel.
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24
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Tekesin I, Hellmeyer L, Heller G, Römer A, Kühnert M, Schmidt S. Evaluation of quantitative ultrasound tissue characterization of the cervix and cervical length in the prediction of premature delivery for patients with spontaneous preterm labor. Am J Obstet Gynecol 2003; 189:532-9. [PMID: 14520230 DOI: 10.1067/s0002-9378(03)00488-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE This study was to evaluate the predictive value of the uterine cervix tissue with the use of quantitative ultrasound gray level analysis for preterm delivery. STUDY DESIGN Sixty-eight patients with preterm labor between 20 and 35 weeks of gestation were included. When two-dimensional transvaginal ultrasound measurement of cervical length was completed, a region of interest of constant size was defined in the midsection of the posterior wall, and the tissue-specific gray scale was determined. Preterm delivery of <37 weeks of gestation was sought. RESULTS Twenty-eight patients (41.2%) were delivered preterm. The risk for preterm delivery was increased significantly in patients with cervical length of </=2.5 cm (odds ratio, 7.67; 95% CI, 2.4-24.45), with Bishop score of >/=4 (odds ratio, 3.44; 95% CI, 1.21-9.75), and with decreased mean gray scale value (odds ratio, 12.13; 95% CI, 3.69-39.88). Parity and uterine contractions were not significant as predictors for preterm delivery, although the risk for preterm delivery increased with higher parity (odds ratio, 1.8; 95% CI, 0.68-4.79). The risk for preterm delivery remained nearly the same by uterine contractions (odds ratio, 0.92; 95% CI, 0.28-3.01). A mean scale value of </=6.54 had the best cutoff value for the prediction of preterm delivery. For preterm delivery, a mean gray value </=6.54 had a sensitivity of 82.1%, a specificity of 72.5%, a positive predictive value of 67.6%, and a negative predictive value 85.3%. Multiple logistic regression analysis indicated that, even when other variables are considered simultaneously, the mean gray scale value is the single best predictor of preterm delivery. CONCLUSION Quantitative ultrasound tissue characterization of the uterine cervix predicts premature delivery and provides additional information in the prediction of potential premature delivery.
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Affiliation(s)
- Ismail Tekesin
- Department of Obstetrics and Perinatal Medicine, Philipps University Marburg, Marburg, Germany.
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25
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Ramos JG, Varayoud J, Bosquiazzo VL, Luque EH, Muñoz-de-Toro M. Cellular turnover in the rat uterine cervix and its relationship to estrogen and progesterone receptor dynamics. Biol Reprod 2002; 67:735-42. [PMID: 12193379 DOI: 10.1095/biolreprod.101.002402] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Histoarchitectural changes of the uterine cervix allow its successful adaptation to different physiological conditions. In this study, we evaluated cell turnover in each cellular compartment of the uterine cervix in association with steroid hormone receptor expression in order to establish the range of physiological changes. Proliferation, apoptosis, and progesterone receptor (PR) and estrogen receptor alpha (ERalpha) expression were evaluated in cycling, pregnant, and postpartum rats. In estrus and diestrus II, ERalpha and PR expression exhibited variations according to the region evaluated. Proliferation and apoptosis showed a reciprocal pattern, the epithelium being the region with higher cell turnover. High apoptotic index (AI) in estrus was associated with the lowest ERalpha and the highest PR scores. During pregnancy, proliferation of the epithelium was the predominant event and AI was low. On Postpartum Day 1 (PPD1), proliferation decreased while apoptosis increased. As described for the estrous cycle, during pregnancy and PPD1, AI and ERalpha were negatively correlated. In the fibroblastic stroma, low proliferation was observed throughout pregnancy; however, there was a net increase in cell number because very few cells underwent apoptosis. No difference in ERalpha was observed in fibroblastic cells during pregnancy and postpartum; however, a great decrease of this receptor in the epithelial compartment was observed after delivery. Unlike cervical epithelium, PR was highly expressed in stromal cells. At term, a dramatic increase in epithelial PR was observed. While epithelial PR remained high on PPD1, a decrease was observed in muscle stroma. These results show that, in all stages studied, 1) ERalpha and PR have different patterns of expression with differential responses to signals that modulate proliferation and/or apoptosis depending on the cellular compartment, and 2) even though the epithelium is the region with the highest cell turnover, the fibroblastic and muscle stroma are active regions that have their own patterns of behavior.
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Affiliation(s)
- Jorge G Ramos
- Laboratorio de Endocrinología y Tumores Hormonodependientes, School of Biochemistry and Biological Sciences, Universidad Nacional del Litoral, 3000 Santa Fe, Argentina
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26
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Abstract
At the time of parturition (fetal delivery) the uterine cervix must "ripen," becoming soft, pliable, and dilated to accommodate the fetus' delivery. The fundamental processes underlying cervical ripening remain poorly understood. Knowledge that abundant autonomic and sensory nerves supply the uterine cervix, that transection of afferent nerves supplying the cervix blocks parturition, and that some of the changes in the cervix resemble those seen in inflammatory reactions suggests nerves may have a role in the cervical ripening changes. The present study utilized immunohistochemistry, plasma extravasation, and solution hybridization-nuclease protection assay to elucidate the complement of primary afferent nerves and some receptors in the rat cervix during pregnancy, and to determine if they may have roles in the ripening process at term. This study revealed an abundance of nerves associated with the cervical vasculature and myometrial smooth muscle containing immunoreactivity for substance P, calcitonin gene-related peptide, secretoneurin, and nitric oxide synthase throughout pregnancy. Many of these are small unmyelinated capsaicin-sensitive C-fibers. Substance P- (NK1-) and calcitonin gene-related peptide receptors were apparent on uterine cervix vasculature from pregnant, parturient, and postpartum rats. NK1 receptor mRNA was maximal at 20 days of pregnancy. Plasma extravasation of i.v. administered Evans Blue or Monastral Blue was most pronounced at parturition (shortly after NK1 mRNA is maximal); this was similar to plasma extravasation evoked by i.v. administration of substance P or capsaicin-treatment. This study revealed new data about the nervous system of the rat uterine cervix and that these nerves and their transmitters could very well be part of a neurogenic inflammatory process involved in cervical ripening.
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Affiliation(s)
- J J Collins
- Department of Neurobiology and Pharmacology, Northeastern Ohio Universities College of Medicine, Rootstown, OH 44272, USA
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Zhao S, Fields PA, Sherwood OD. Evidence that relaxin inhibits apoptosis in the cervix and the vagina during the second half of pregnancy in the rat. Endocrinology 2001; 142:2221-9. [PMID: 11356666 DOI: 10.1210/endo.142.6.8182] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The growth of the cervix and vagina that occurs during the second half of rat pregnancy is accompanied by an increase in both epithelial and stromal cells. Neither the mechanism(s) that regulates this accumulation of cells nor its hormonal control is known. To test the hypothesis that the rate of apoptosis declines during the second half of pregnancy, cervices and vaginas were collected on days 5, 10, 15, 18, and 21 of pregnancy. Terminal deoxynucleotidyl transferase-mediated deoxyuridine 5'-triphosphate nick end-labeling was used to detect apoptotic cells. The rate of apoptosis declined (P < 0.05) in epithelial and stromal cells in both the cervix and vagina during the second half of pregnancy, when blood levels of relaxin are increasing. To test the hypothesis that relaxin inhibits apoptosis, cervices and vaginas were collected 6, 12, 24, 48, and 72 h after the neutralization of endogenous relaxin, on days 19-21 of pregnancy, with a monoclonal antibody for rat relaxin. Both the terminal deoxynucleotidyl transferase-mediated deoxyuridine 5'-triphosphate nick end-labeling method and electron microscopy were used to detect apoptotic cells. Withdrawal of relaxin caused an increase in the rate of apoptosis in both the cervix and the vagina (P < 0.05). It is concluded that the rate of apoptosis declines in the cervix and the vagina during the second half of rat pregnancy, and that relaxin likely contributes to this process.
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Affiliation(s)
- S Zhao
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 61801, USA
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29
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Leppert PC, Kokenyesi R, Klemenich CA, Fisher J. Further evidence of a decorin-collagen interaction in the disruption of cervical collagen fibers during rat gestation. Am J Obstet Gynecol 2000; 182:805-11; discussion 811-2. [PMID: 10764456 DOI: 10.1016/s0002-9378(00)70329-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Our purpose was to determine the histologic distribution and expression of decorin in rat cervix throughout the course of rat gestation and to correlate the findings with the known progression of collagen fiber disruption and cellular turnover in this tissue. STUDY DESIGN Cervices from pregnant animals at 5, 11, 18, and 21 days were studied. A proteoglycan of low molecular weight, decorin, was detected by sensitive and specific immunohistochemical analysis with a biotin-avidin horseradish peroxidase method. RESULTS Decorin was not detected on day 5. By day 11 moderate decorin staining was detected in the subepithelial layer and in the deep stroma. Decorin staining progressed to a strong expression in the subepithelial layer and to a moderate expression in the deep stroma on day 18. On day 21 (term in rat) the staining was fairly homogeneous throughout the connective tissue stroma. CONCLUSION These findings clearly demonstrate that decorin expression increased progressively throughout pregnancy and are consistent with the hypothesis that an excess of decorin near term is capable of initiating a decorin-collagen interaction that leads to collagen fibril disruption and decreased cervical tensile strength.
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Affiliation(s)
- P C Leppert
- Department of Obstetrics and Gynecology, St Louis University, Missouri, USA
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30
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Abstract
Induction of labor is indicated when the benefits to either the mother or the fetus outweigh the benefits of continuing the pregnancy. The state of the cervix is clearly related to the success of labor induction and the duration of labor. In cases of unfavorable cervices, physicians usually use a ripening agent before inducing labor. Unfortunately, as reviewed in this article, the ideal ripening agent is not found yet. No method of cervical ripening has shown a consistent and significant reduction in CS rate. In fact, women with the most unfavorable cervices (Bishop score, < or = 2) still face high rates of induction failure and CS.
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Affiliation(s)
- S Riskin-Mashiah
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, USA
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Tschugguel W, Schneeberger C, Lass H, Stonek F, Zaghlula MB, Czerwenka K, Schatten C, Kaider A, Husslein P, Huber JC. Human cervical ripening is associated with an increase in cervical inducible nitric oxide synthase expression. Biol Reprod 1999; 60:1367-72. [PMID: 10330094 DOI: 10.1095/biolreprod60.6.1367] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The mechanisms that ultimately regulate cervical ripening during parturition remain largely unknown. A possible role for nitric oxide (NO) has recently emerged; however, the expression of NO synthase (NOS) within the human cervix in the ripening process has not been investigated. The purpose of this study was to identify cell types in the human cervix that contain NOS isoforms and to examine changes in their expression during the ripening process and the nonpregnant state. Inducible NOS (iNOS) immunoreactivity was observed in the epithelial cells and stromal spindle cells in 17 of 20 biopsies from cervices obtained within 10 min postpartum, but in only 4 of 12 nonpregnant controls (p = 0.03). Endothelial NOS (eNOS) immunoreactivity was restricted to vascular endothelia in all sections, whereas neuronal NOS was not detectable. Inducible NOS activity in the postpartum group was 3.2 times that of the control group (p = 0.0005), whereas constitutive NOS activity remained unchanged in both groups (p = 0.222). Competitive reverse transcription-polymerase chain reaction revealed no differences in the expression of iNOS (p = 0.443) or eNOS mRNA (p = 0.409). The existence of iNOS in the human postpartum cervix suggests that increased production of NO, probably induced by cytokines, may be relevant to the process of natural cervical ripening in humans.
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Affiliation(s)
- W Tschugguel
- Department of Gynecology and Obstetrics, University of Vienna, Austria.
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Lei H, Kalluri R, Furth EE, Baker AH, Strauss JF. Rat amnion type IV collagen composition and metabolism: implications for membrane breakdown. Biol Reprod 1999; 60:176-82. [PMID: 9858503 DOI: 10.1095/biolreprod60.1.176] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
We report here that rat amnion type IV collagens are composed primarily of alpha1(IV) and alpha2(IV) chains. Amnion basement membrane collagens were more sensitive to degradation by collagenases than were adult rat kidney basement membrane collagens, which are enriched in alpha3(IV), alpha4(IV), and alpha6(IV) chains. Amnion type IV collagen content per unit of protein was markedly reduced by Day 21 of pregnancy, the day of delivery. Increased amnion levels of matrix metalloproteinase (MMP)-2 and MMP-9, gelatinases that degrade type IV collagen, were found by Day 21, suggesting that collagen breakdown was responsible, in part, for the decline in amnion type IV collagen. Infection of organ cultures of Day 18 rat amnions with a recombinant adenovirus expressing MMP-9 (AdMMP-9) caused release of collagen fragments detected as hydroxyproline in the culture fluid, amnion cell detachment, and apoptosis. The AdMMP-9-induced apoptosis was prevented by the MMP inhibitor batimastat. These findings suggest that MMPs are implicated in anoikis and apoptotic death of amnion cells, and may be part of a complex program of fetal membrane remodeling that occurs before delivery.
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Affiliation(s)
- H Lei
- Center for Research on Reproduction and Women's Health and Department of Obstetrics and Gynecology, University of Pennsylvania Medical Center, Philadelphia 19104, USA
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Takamoto N, Leppert PC, Yu SY. Cell death and proliferation and its relation to collagen degradation in uterine involution of rat. Connect Tissue Res 1998; 37:163-75. [PMID: 9862218 DOI: 10.3109/03008209809002436] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Collagen concentration, procollagenase localization, and their association with cell proliferation and apoptosis during postpartum involution, were investigated biochemically and histochemically in postpartum day 1, 3, 5, and 7 rat uterine tissues. In control animals, uterine wet weight, soluble protein, and collagen decreased rapidly during days 1 to 3 postpartum, and the DNA concentration in the uterine horn rapidly decreased, as noted by others. Simultaneously, both apoptosis and cell proliferation were observed in these tissues. These processes were highest in smooth muscle cells on day 3 postpartum. Procollagenase was found in the cell cytoplasm through days 1 to 3 postpartum, was highest on the third day postpartum, and appeared to gradually diminish by day 5 postpartum. Disorganization of collagen fibers was observed, under polarized microscopy by a strong birefringence of collagen fibers of the circular smooth muscle cell layers. However, this disorganization of the uterine collagen diminished progressively from day 3 to day 7. Treatment with estradiol or a combination of estradiol and progesterone suppressed cellular turnover and attenuated the changes in DNA, total amino acids, and collagen on day 3 postpartum. In this study, cellular turnover and biochemical and morphological changes appeared to be closely associated. Gonadal steroid hormones appear to influence these changes and retard uterine involution. This study suggests that a dynamic turnover of the cellular population takes place during uterine involution. It is possible that other factors, in addition to steroid hormones, contribute to uterine involution. It is to be postulated that these factors either are themselves decreased or, alternatively, may increase the inhibition of other unknown factors by an indirect mechanism.
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Affiliation(s)
- N Takamoto
- Department of Obstetrics and Gynecology, University of Rochester School of Medicine and Dentistry, Rochester General Hospital, NY 14621, USA
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Burger LL, Sherwood OD. Relaxin increases the accumulation of new epithelial and stromal cells in the rat cervix during the second half of pregnancy. Endocrinology 1998; 139:3984-95. [PMID: 9724054 DOI: 10.1210/endo.139.9.6210] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Both cervical and vaginal growth are relaxin dependent during rat pregnancy. We recently reported a relaxin-dependent 1.5-fold increase in cervical and vaginal DNA content from midpregnancy until term. This finding indicated that relaxin probably promotes cervical and vaginal growth at least in part by promoting cellular proliferation. The objective of this study was to identify and quantify cells in the cervix and vagina that proliferate during the second half of rat pregnancy in response to relaxin. Primiparous pregnant rats were ovariectomized or sham ovariectomized (group C; n = 8) on day 9 of pregnancy (D9). Ovariectomized rats were then treated with physiological doses of progesterone plus estrogen (n = 7) or progesterone, estrogen, and porcine relaxin (n = 7). Cellular proliferation was determined by continuously administering a low dose of 5-bromo-2'-deoxyuridine (BrdU) via miniature osmotic pump from D9-D22. On D22, cervices and vaginas were collected, fixed in formalin, paraffin embedded, and serially sectioned (4 microm). Adjacent serial sections were either immunostained for BrdU to assess cell proliferation or stained with hematoxylin to determine total cell number. Cell proliferation was evaluated by counting BrdU-positive nuclei and total nuclei in the same area on adjacent sections. Cell counts were determined using computerized digital morphometric analysis at x575. In control rats, nearly 75% of the epithelial cells and 55% of the stromal cells within the cervix at term had proliferated during the second half of pregnancy. The accumulation of approximately half of the new cells was relaxin dependent. Within the cervical stroma, relaxin increased the accumulation of cells associated with blood vessels and also the number of isolated cells (probably fibroblasts). Relaxin did not appear to affect smooth muscle cell proliferation in the cervix. In contrast to the cervix, a minority of vaginal epithelial cells (45%) and stromal cells (20%) proliferated during the second half of pregnancy. Although relaxin appeared to have a tendency to increase the accumulation of new vaginal epithelial and stromal cells, morphometric analysis did not provide support for such an effect. In conclusion, this study demonstrates that relaxin promotes a marked increase in the accumulation of new epithelial cells and stromal cells within the cervix. The relaxin-induced increase in new epithelial and stromal cells probably contributes to relaxin's effects on growth and remodeling of the cervix that are required for rapid and safe delivery.
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Affiliation(s)
- L L Burger
- Department of Molecular in Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana 61801, USA
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Leppert PC. Proliferation and apoptosis of fibroblasts and smooth muscle cells in rat uterine cervix throughout gestation and the effect of the antiprogesterone onapristone. Am J Obstet Gynecol 1998; 178:713-25. [PMID: 9579433 DOI: 10.1016/s0002-9378(98)70481-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The purpose of this study was to determine the relative percentages of apoptosis and proliferation in fibroblasts and cervical smooth muscles throughout gestation and the effect of an antiprogesterone on these processes. STUDY DESIGN Rats were studied at days 5, 15, 18, and 21 and immediately postpartum (day 22). Apoptosis and proliferation as detected by specific immunohistochemistry quantitative morphometric analysis was performed. Onapristone, an antiprogesterone, was used to study effects of hormonal change on these processes in 16- and 19-day timed-pregnant rats. RESULTS Proliferation of fibroblasts and smooth muscle cells was highest in early pregnancy and decreased progressively, whereas apoptosis increased progressively in later pregnancy. Onapristone inhibited apoptosis. CONCLUSION Changes in cervical cellular turnover are initiated early in gestation and are under hormonal influence. Antiprogesterone inhibits cell death at days 16 and 19 of gestation.
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Affiliation(s)
- P C Leppert
- Department of Gynecology-Obstetrics, State University of New York at Buffalo, 14222, USA
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