Cyclic Stretch Augments Production of Neutrophil Chemokines, Matrix Metalloproteinases, and Activin A in Human Endometrial Stromal Cells

Contrast-Enhanced Ultrasonography as a Diagnostic Strategy for Severe Endometrial Injury

ABSTRACT

Endometrial injury is associated with poorer pregnancy outcomes. The purpose of this study was to evaluate the diagnostic efficacy of contrast-enhanced ultrasonography (CEUS) in the detection of endometrial injury. This study included women who underwent CEUS of the uterus at the author's hospital between April 2020 and January 2021. The diagnostic performances of the CEUS-derived parameters in the detection of severe endometrial injury were evaluated by receiver operating characteristic curve analyses. The study included 67 participants (healthy control, n = 14; mild endometrial injury, n = 24; severe endometrial injury, n = 29). Enhancement intensity (EI) and area under the time-intensity curve (AUC TIC ) were significantly lower in the severe endometrial injury patients than healthy and mild endometrial injury subjects for both endometrial and subendometrial regions ( P < 0.05). Correlations analysis showed that EI and AUC TIC were positively correlated with endometrial thickness ( r = 0.460, P = 0.01, and r = 0.555, P < 0.01, respectively) and subendometrial thickness ( r = 0.501, P < 0.01, and r = 0.438, P = 0.01, respectively). The area under the receiver operating characteristic curve, sensitivity, and specificity were 0.720 ( P = 0.002), 79.31%, and 66.67% for endometrial EI; 0.818 ( P < 0.001), 75.86%, and 79.17% for subendometrial EI; 0.917 ( P < 0.001), 72.41%, and 95.83% for endometrial AUC TIC ; and 0.810 ( P < 0.001), 89.66%, and 70.83% for subendometrial AUC TIC , respectively. Contrast-enhanced ultrasonography may have clinical utility in the prediction of endometrial injury in women of childbearing age.

Modelling fibroid pathology: development and manipulation of a myometrial smooth muscle cell macromolecular crowding model to alter extracellular matrix deposition

Current treatment options for uterine fibroids are limited to hormonal manipulation or surgical intervention. We aimed to develop an in vitro model to mirror collagen deposition and extracellular matrix (ECM) formation, the principal features of uterine fibroids, to enable testing of novel therapeutics. Macromolecular crowding with Ficoll 400 and Ficoll 70 in cultures of human uterine myometrial smooth muscle cells containing ascorbic acid, provided the basis for this model. These culture conditions mimic the 'crowded' nature of the in vivo extracellular environment by incorporating neutral, space-filling macromolecules into conventional cell cultures. This method of culture facilitates appropriate ECM deposition, thus closely representing the in vivo fibrotic phenotype of uterine fibroids. Macromolecular crowding in Ficoll cultures containing ascorbic acid reduced myometrial smooth muscle cell proliferation and promoted collagen production. Under these conditions, collagen was processed for extracellular deposition as demonstrated by C-propeptide cleavage from secreted procollagen. The fibrosis marker activin was increased relative to its natural inhibitor, follistatin, in crowded culture conditions while addition of exogenous follistatin reduced collagen (Col1A1) gene expression. This in vitro model represents a promising development for the testing of therapeutic interventions for uterine fibroids. However, it does not recapitulate the full in vivo pathology which can include specific genetic and epigenetic alterations that have not been identified in the myometrial smooth muscle (hTERT-HM) cell line. Following screening of potential therapeutics using the model, the most promising compounds will require further assessment in the context of individual subjects including those with genetic changes implicated in fibroid pathogenesis.

Inside the Endometrial Cell Signaling Subway: Mind the Gap(s)

Endometrial cells perceive and respond to their microenvironment forming the basis of endometrial homeostasis. Errors in endometrial cell signaling are responsible for a wide spectrum of endometrial pathologies ranging from infertility to cancer. Intensive research over the years has been decoding the sophisticated molecular means by which endometrial cells communicate to each other and with the embryo. The objective of this review is to provide the scientific community with the first overview of key endometrial cell signaling pathways operating throughout the menstrual cycle. On this basis, a comprehensive and critical assessment of the literature was performed to provide the tools for the authorship of this narrative review summarizing the pivotal components and signaling cascades operating during seven endometrial cell fate “routes”: proliferation, decidualization, implantation, migration, breakdown, regeneration, and angiogenesis. Albeit schematically presented as separate transit routes in a subway network and narrated in a distinct fashion, the majority of the time these routes overlap or occur simultaneously within endometrial cells. This review facilitates identification of novel trajectories of research in endometrial cellular communication and signaling. The meticulous study of endometrial signaling pathways potentiates both the discovery of novel therapeutic targets to tackle disease and vanguard fertility approaches.

Role for Mechanotransduction in Macrophage and Dendritic Cell Immunobiology

Tissue homeostasis is not only controlled by biochemical signals but also through mechanical forces that act on cells. Yet, while it has long been known that biochemical signals have profound effects on cell biology, the importance of mechanical forces has only been recognized much more recently. The types of mechanical stress that cells experience include stretch, compression, and shear stress, which are mainly induced by the extracellular matrix, cell-cell contacts, and fluid flow. Importantly, macroscale tissue deformation through stretch or compression also affects cellular function.Immune cells such as macrophages and dendritic cells are present in almost all peripheral tissues, and monocytes populate the vasculature throughout the body. These cells are unique in the sense that they are subject to a large variety of different mechanical environments, and it is therefore not surprising that key immune effector functions are altered by mechanical stimuli. In this chapter, we describe the different types of mechanical signals that cells encounter within the body and review the current knowledge on the role of mechanical signals in regulating macrophage, monocyte, and dendritic cell function.

Uterine overdistention induces preterm labor mediated by inflammation: observations in pregnant women and nonhuman primates

OBJECTIVE

Uterine overdistention is thought to induce preterm labor in women with twin and multiple pregnancies, but the pathophysiology remains unclear. We investigated for the first time the pathogenesis of preterm birth associated with rapid uterine distention in a pregnant nonhuman primate model.

STUDY DESIGN

A nonhuman primate model of uterine overdistention was created using preterm chronically catheterized pregnant pigtail macaques (Macaca nemestrina) by inflation of intraamniotic balloons (N = 6), which were compared to saline controls (N = 5). Cesarean delivery was performed due to preterm labor or at experimental end. Microarray, quantitative reverse transcriptase polymerase chain reaction, Luminex (Austin, TX), and enzyme-linked immunosorbent assay were used to measure messenger RNA (mRNA) and/or protein levels from monkey (amniotic fluid, myometrium, maternal plasma) and human (amniocytes, amnion, myometrium) tissues. Statistical analysis employed analysis of covariance and Wilcoxon rank sum. Biomechanical forces were calculated using the law of Laplace.

RESULTS

Preterm labor occurred in 3 of 6 animals after balloon inflation and correlated with greater balloon volume and uterine wall stress. Significant elevations of inflammatory cytokines and prostaglandins occurred following uterine overdistention in an "inflammatory pulse" that correlated with preterm labor (interleukin [IL]-1β, tumor necrosis factor [TNF]-α, IL-6, IL-8, CCL2, prostaglandin E2, prostaglandin F2α, all P < .05). A similar inflammatory response was observed in amniocytes in vitro following mechanical stretch (IL1β, IL6, and IL8 mRNA multiple time points, P < .05), in amnion of women with polyhydramnios (IL6 and TNF mRNA, P < .05) and in amnion (TNF-α) and myometrium of women with twins in early labor (IL6, IL8, CCL2, all P < .05). Genes differentially expressed in the nonhuman primate after balloon inflation and in women with polyhydramnios and twins are involved in tissue remodeling and muscle growth.

CONCLUSION

Uterine overdistention by inflation of an intraamniotic balloon is associated with an inflammatory pulse that precedes and correlates with preterm labor. Our results indicate that inflammation is an early event after a mechanical stress on the uterus and leads to preterm labor when the stress is sufficiently great. Further, we find evidence of uterine tissue remodeling and muscle growth as a common, perhaps compensatory, response to uterine distension.