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Biology of Reproduction Aug 2017Preterm birth continues to be a significant public health problem. Infection (bacterial and or viral) and inflammation, by stimulating proinflammatory cytokines,...
Preterm birth continues to be a significant public health problem. Infection (bacterial and or viral) and inflammation, by stimulating proinflammatory cytokines, adhesion molecules, and matrix metalloproteinase 9 (MMP9), play a central role in the rupture of membranes and myometrial contractions. SMAD7 has been implicated in regulating the inflammatory response; however, no studies have been performed with regard to human labor. In this study, we determined the effect of spontaneous human labor and prolabor mediators on SMAD7 expression in myometrium and fetal membranes. Functional studies were employed to investigate the effect of siRNA knockdown of SMAD7 (siSMAD7) in regulating infection and inflammation-induced prolabor mediators. SMAD7 mRNA and protein expression were significantly higher with spontaneous term labor, compared to no labor, in myometrium and fetal membranes. SMAD7 expression was also significantly higher in amnion from women with preterm chorioamnionitis. The proinflammatory cytokines IL1B and TNF, the bacterial product fsl-1, and the viral dsRNA analog poly(I:C) significantly increased SMAD7 in myometrial cells and amnion cells. In myometrial cells, siSMAD7 cells significantly decreased cytokine (IL6) and chemokine (CXCL1, CXCL8, CCL2 are also known as GRO-alpha, interleukin (IL)-8 and monocyte chemotactic protein-1 (MCP-1)) production induced by IL1B, TNF, and fsl-1. There was also a decrease in the expression of adhesion molecules intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1) in siSMAD7 cells, and MMP9 expression. In amnion, siSMAD7 cells treated with IL1B also decreased cytokine and chemokine production, ICAM1 and MMP9 expression. In conclusion, we report a proinflammatory role for SMAD7 in human gestational tissues, with SMAD7 silencing attenuating the inflammatory response.
Topics: Amnion; Biopsy; Female; Gene Expression Regulation; Humans; Labor, Obstetric; Myometrium; Pregnancy; RNA Interference; RNA, Small Interfering; Smad7 Protein
PubMed: 29044425
DOI: 10.1093/biolre/iox080 -
Experimental Biology and Medicine... May 2021The myometrium is the smooth muscle layer of the uterus that generates the contractions that drive processes such as menstruation and childbirth. Aberrant contractions... (Review)
Review
The myometrium is the smooth muscle layer of the uterus that generates the contractions that drive processes such as menstruation and childbirth. Aberrant contractions of the myometrium can result in preterm birth, insufficient progression of labor, or other difficulties that can lead to maternal or fetal complications or even death. To investigate the underlying mechanisms of these conditions, the most common model systems have conventionally been animal models and human tissue strips, which have limitations mostly related to relevance and scalability, respectively. Myometrial smooth muscle cells have also been isolated from patient biopsies and cultured as a more controlled experimental system. However, approaches have focused primarily on measuring the effects of biochemical stimuli and neglected biomechanical stimuli, despite the extensive evidence indicating that remodeling of tissue rigidity or excessive strain is associated with uterine disorders. In this review, we first describe the existing approaches for modeling human myometrium with animal models and human tissue strips and compare their advantages and disadvantages. Next, we introduce existing techniques and assays for assessing contractility and summarize their applications in elucidating the role of biochemical or biomechanical stimuli on human myometrium. Finally, we conclude by proposing the translation of "organ on chip" approaches to myometrial smooth muscle cells as new paradigms for establishing their fundamental mechanobiology and to serve as next-generation platforms for drug development.
Topics: Animals; Biophysical Phenomena; Female; Humans; In Vitro Techniques; Models, Animal; Models, Biological; Myocytes, Smooth Muscle; Myometrium
PubMed: 33554648
DOI: 10.1177/1535370221989259 -
Cells Feb 2023Preterm birth is the leading cause of childhood mortality and morbidity. A better understanding of the processes that drive the onset of human labour is essential to...
Preterm birth is the leading cause of childhood mortality and morbidity. A better understanding of the processes that drive the onset of human labour is essential to reduce the adverse perinatal outcomes associated with dysfunctional labour. Beta-mimetics, which activate the myometrial cyclic adenosine monophosphate (cAMP) system, successfully delay preterm labour, suggesting a key role for cAMP in the control of myometrial contractility; however, the mechanisms underpinning this regulation are incompletely understood. Here we used genetically encoded cAMP reporters to investigate cAMP signalling in human myometrial smooth muscle cells at the subcellular level. We found significant differences in the dynamics of the cAMP response in the cytosol and at the plasmalemma upon stimulation with catecholamines or prostaglandins, indicating compartment-specific handling of cAMP signals. Our analysis uncovered significant disparities in the amplitude, kinetics, and regulation of cAMP signals in primary myometrial cells obtained from pregnant donors compared with a myometrial cell line and found marked response variability between donors. We also found that in vitro passaging of primary myometrial cells had a profound impact on cAMP signalling. Our findings highlight the importance of cell model choice and culture conditions when studying cAMP signalling in myometrial cells and we provide new insights into the spatial and temporal dynamics of cAMP in the human myometrium.
Topics: Pregnancy; Female; Humans; Infant, Newborn; Myometrium; Premature Birth; Cyclic AMP; Cell Line; Prostaglandins
PubMed: 36899855
DOI: 10.3390/cells12050718 -
Experimental Physiology Dec 2015What is the topic of this review? I focus on clinical aspects of uterine physiology, specifically, myometrial contractility. I bring together and contrast findings using... (Review)
Review
What is the topic of this review? I focus on clinical aspects of uterine physiology, specifically, myometrial contractility. I bring together and contrast findings using physiological approaches and those using newer techniques, 'omics'. What advances does it highlight? Physiological studies have recently shed light on the myometrium in twin pregnancies, but there have been no 'omic' approaches. In contrast, studies of preterm delivery using newer approaches are generating new research avenues, whereas traditional approaches have not flourished. Finally, I describe significant advances in understanding of 'slow-to-progress' labours, achieved using physiological and clinical approaches. Advances in molecular, genetic and 'omic' technologies are fuelling the thirst for better understanding of the uterus and application of this information to problems in pregnancy and labour. Progress has, however, been limited while we still have an incomplete understanding of some of the basic physiology of uterine smooth muscle (myometrium). In this review and opinion piece, I explore some of the fascinating findings from selected recent studies and see how these may provide new avenues for physiological and clinical research. It is also the case, however, that there is still limited mechanistic understanding about physiological and pathophysiological processes in the myometrium. This lack of understanding limits the usefulness of some findings from genomic and allied studies. By focusing on some key recent findings and relating these to two important clinical problems in childbirth that involve myometrial activity, namely preterm delivery and difficult labours, the interplay between our physiological knowledge and the information provided by newer technologies is explored. My opinion is that physiology has provided much more new mechanistic insight into difficult births and that the newer technologies may lead to breakthroughs in preterm birth research, but that this has not yet happened.
Topics: Animals; Female; Humans; Muscle, Smooth; Myometrium; Uterus
PubMed: 26289390
DOI: 10.1113/EP085131 -
Current Opinion in Obstetrics &... Oct 2019Uterine leiomyomas are the most common benign uterine smooth muscle tumors. On the basis of imaging, these masses are often presumed to be benign conventional leiomyomas... (Review)
Review
PURPOSE OF REVIEW
Uterine leiomyomas are the most common benign uterine smooth muscle tumors. On the basis of imaging, these masses are often presumed to be benign conventional leiomyomas and surgical excision is a common treatment choice. After myomectomy or hysterectomy for presumed leiomyomas, the surgical pathology report may reveal an unexpected diagnosis of another type of mesenchymal tumor. These can range from a variant of benign smooth muscle tumors to smooth muscle tumors of uncertain malignant potential to malignant sarcomas. This review describes these variant pathologies and reviews data on recurrence risk and postoperative management.
RECENT FINDINGS
The majority of benign smooth muscle tumors will be classified as leiomyomas. Cellular, bizarre nuclei, mitotically active, epitheliod, myxoid, and dissecting are all terms that describe pathologic variants of benign leiomyomas. Smooth muscle tumors of uncertain malignant potential contain both benign and malignant features and should be referred to Gynecologic Oncology for follow-up. Leiomyosarcomas and low-grade endometrial stromal sarcomas may present preoperatively as benign tumors but are malignant with a high risk of recurrence and should be referred to Gynecologic Oncology.
SUMMARY
We advocate for the continued benefits of minimally invasive procedures in appropriately selected patients. Despite these measures, unexpected pathologic diagnoses can occur and should be managed appropriately.
Topics: Female; Humans; Hysterectomy; Leiomyoma; Leiomyosarcoma; Myometrium; Uterine Myomectomy; Uterine Neoplasms
PubMed: 31425175
DOI: 10.1097/GCO.0000000000000569 -
Acta Physiologica (Oxford, England) Feb 2015In this review, we give a state-of-the-art account of uterine contractility, focussing on excitation-contraction (electro-mechanical) coupling (ECC). This will show how... (Review)
Review
In this review, we give a state-of-the-art account of uterine contractility, focussing on excitation-contraction (electro-mechanical) coupling (ECC). This will show how electrophysiological data and intracellular calcium measurements can be related to more modern techniques such as confocal microscopy and molecular biology, to advance our understanding of mechanical output and its modulation in the smooth muscle of the uterus, the myometrium. This new knowledge and understanding, for example concerning the role of the sarcoplasmic reticulum (SR), or stretch-activated K channels, when linked to biochemical and molecular pathways, provides a clearer and better informed basis for the development of new drugs and targets. These are urgently needed to combat dysfunctions in excitation-contraction coupling that are clinically challenging, such as preterm labour, slow to progress labours and post-partum haemorrhage. It remains the case that scientific progress still needs to be made in areas such as pacemaking and understanding interactions between the uterine environment and ion channel activity.
Topics: Animals; Calcium Signaling; Female; Humans; Muscle, Smooth; Myometrium; Sarcoplasmic Reticulum; Uterine Contraction; Uterus
PubMed: 25439280
DOI: 10.1111/apha.12431 -
Gynecologic and Obstetric Investigation 2020The junctional zone endometrium (JZE) is a compacted layer of smooth muscle cells with little extracellular matrix. The innermost myometrium adjacent to the endometrium,... (Review)
Review
The junctional zone endometrium (JZE) is a compacted layer of smooth muscle cells with little extracellular matrix. The innermost myometrium adjacent to the endometrium, JZE is best visualized and evaluated on T2-weighted magnetic resonance imaging (MRI) and two-dimensional/three-dimensional transvaginal ultrasound (TVUS) scanning. Increased thickness of JZE >12 mm on MRI images has been associated with myometrial and subendometrial pathologic conditions, such as, adenomyosis, and is considered a poor prognostic factor for implantation. Gonadotrophin-releasing hormone analogue (GnRHa) has been proposed as a treatment for adenomyosis and fibroids larger than 7 cm, and overall improvement in symptoms and disease progression were attributed to JZE thinning after GnRHa treatment. JZE contractility and frequency of contractions are affected by ovarian hormone cyclic activity and pathologic changes adjacent to JZE, such as fibroids and polyps. However, JZE contractility is not evaluated by TVUS during gynecological examinations because guidelines do not exist and the process is time consuming. The present data indicate that JZE is an important part of the nongravid uterus anatomy, structure, and functionality. When more evidence is available, the morphologic features, thickness, and contractility of JZE may potentially be used as markers for diagnosis and prognosis of normal and abnormal uterine function, for early stages of pregnancy, and possibly for early detection of endometrial cancer. A new tool for JZE measurements should be further investigated to fill this clinical gap. Key Message: JZE is an important component of the nongravid uterus anatomy, structure, and functionality. The thickness and contractility of JZE could potentially be used as markers for diagnosis and prognosis of normal and abnormal uterine function, early stages of pregnancy, and early detection of endometrial cancer. A new tool for JZE measurements should be further investigated.
Topics: Adenomyosis; Adult; Embryo Implantation; Endometrial Neoplasms; Endometrium; Female; Humans; Leiomyoma; Magnetic Resonance Imaging; Myometrium; Pregnancy; Ultrasonography; Uterine Neoplasms; Uterus
PubMed: 31968333
DOI: 10.1159/000505650 -
Clinical and Translational Medicine Apr 2023The transition of the myometrium from a quiescent to a contractile state during labour is known to involve inflammation, which is characterized by the infiltration of...
BACKGROUND
The transition of the myometrium from a quiescent to a contractile state during labour is known to involve inflammation, which is characterized by the infiltration of immune cells and the secretion of cytokines. However, the specific cellular mechanisms underlying inflammation in the myometrium during human parturition are not yet fully understood.
METHODS
Through the analysis of transcriptomics, proteomics, and cytokine arrays, the inflammation in the human myometrium during labour was revealed. By performing single-cell RNA sequencing (scRNA-seq) and spatiotemporal transcriptomic (ST) analyses on human myometrium in term in labour (TIL) and term in non-labour (TNL), we established a comprehensive landscape of immune cells, their transcriptional characteristics, distribution, function and intercellular communications during labour. Histological staining, flow cytometry, and western blotting were applied to validate some results from scRNA-seq and ST.
RESULTS
Our analysis identified immune cell types, including monocytes, neutrophils, T cells, natural killer (NK) cells and B cells, present in the myometrium. TIL myometrium had a higher proportion of monocytes and neutrophils than TNL myometrium. Furthermore, the scRNA-seq analysis showed an increase in M1 macrophages in TIL myometrium. CXCL8 expression was mainly observed in neutrophils and increased in TIL myometrium. CCL3 and CCL4 were principally expressed in M2 macrophages and neutrophils-6, and decreased during labour; XCL1 and XCL2 were specifically expressed in NK cells, and decreased during labour. Analysis of cytokine receptor expression revealed an increase in IL1R2, which primarily expressed in neutrophils. Finally, we visualized the spatial proximity of representative cytokines, contraction-associated genes, and corresponding receptors in ST to demonstrate their location within the myometrium.
CONCLUSIONS
Our analysis comprehensively revealed changes in immune cells, cytokines, and cytokine receptors during labour. It provided a valuable resource to detect and characterize inflammatory changes, yielding insights into the immune mechanisms underlying labour.
Topics: Female; Humans; Myometrium; Transcriptome; Cytokines; Inflammation; Sequence Analysis, RNA
PubMed: 37095651
DOI: 10.1002/ctm2.1234 -
Protein & Cell Jul 2024Adenomyosis is a poorly understood gynecological disorder lacking effective treatments. Controversy persists regarding "invagination" and "metaplasia" theories. The...
Adenomyosis is a poorly understood gynecological disorder lacking effective treatments. Controversy persists regarding "invagination" and "metaplasia" theories. The endometrial-myometrial junction (EMJ) connects the endometrium and myometrium and is important for diagnosing and classifying adenomyosis, but its in-depth study is just beginning. Using single-cell RNA sequencing and spatial profiling, we mapped transcriptional alterations across eutopic endometrium, lesions, and EMJ. Within lesions, we identified unique epithelial (LGR5+) and invasive stromal (PKIB+) subpopulations, along with WFDC1+ progenitor cells, supporting a complex interplay between "invagination" and "metaplasia" theories of pathogenesis. Further, we observed endothelial cell heterogeneity and abnormal angiogenic signaling involving vascular endothelial growth factor and angiopoietin pathways. Cell-cell communication differed markedly between ectopic and eutopic endometrium, with aberrant signaling in lesions involving pleiotrophin, TWEAK, and WNT cascades. This study reveals unique stem cell-like and invasive cell subpopulations within adenomyosis lesions identified, dysfunctional signaling, and EMJ abnormalities critical to developing precise diagnostic and therapeutic strategies.
Topics: Humans; Female; Adenomyosis; Single-Cell Analysis; Transcriptome; Endometrium; Sequence Analysis, RNA; Myometrium
PubMed: 38486356
DOI: 10.1093/procel/pwae012 -
American Journal of Obstetrics and... May 2023Organ-level models are used to describe how cellular and tissue-level contractions coalesce into clinically observable uterine contractions. More importantly, these... (Review)
Review
Organ-level models are used to describe how cellular and tissue-level contractions coalesce into clinically observable uterine contractions. More importantly, these models provide a framework for evaluating the many different contraction patterns observed in laboring patients, ideally offering insight into the pitfalls of currently available recording modalities and suggesting new directions for improving recording and interpretation of uterine contractions. Early models proposed wave-like propagation of bioelectrical activity as the sole mechanism for recruiting the myometrium to participate in the contraction and increase contraction strength. However, as these models were tested, the results consistently revealed that sequentially propagating waves do not travel long distances and do not encompass the gravid uterus. To resolve this discrepancy, a model using 2 mechanisms, or a "dual model," for organ-level signaling has been proposed. In the dual model, the myometrium is recruited by action potentials that propagate wave-like as far as 10 cm. At longer distances, the myometrium is recruited by a mechanotransduction mechanism that is triggered by rising intrauterine pressure. In this review, we present the influential models of uterine function, highlighting their main features and inconsistencies, and detail the role of intrauterine pressure in signaling and cervical dilation. Clinical correlations demonstrate the application of organ-level models. The potential to improve the recording and clinical interpretation of uterine contractions when evaluating labor is discussed, with emphasis on uterine electromyography. Finally, 7 questions are posed to help guide future investigations on organ-level signaling mechanisms.
Topics: Pregnancy; Female; Humans; Uterine Contraction; Mechanotransduction, Cellular; Labor, Obstetric; Myometrium; Uterus
PubMed: 37164493
DOI: 10.1016/j.ajog.2022.10.039