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Context: Cervical excision is a risk factor for preterm birth. This suggests that the cervix plays an essential role in the maintenance of pregnancy., Objective: We investigated the role of the cervix through proteomic analysis of cervicovaginal fluid (CVF) from pregnant women after trachelectomy surgery, the natural model of a lack of cervix., Methods: The proteome compositions of CVF in pregnant women after trachelectomy were compared with those in control pregnant women by liquid chromatography-tandem mass spectrometry and label-free relative quantification. MUC5B/AC expression in the human and murine cervices was analyzed by immunohistochemistry. Regulation of MUC5B/AC expression by sex steroids was assessed in primary human cervical epithelial cells. In a pregnant mouse model of ascending infection, Escherichia coli or phosphate-buffered saline was inoculated into the vagina at 16.5 dpc, and the cervices were collected at 17.5 dpc., Results: The expression of MUC5B/5AC in cervicovaginal fluid was decreased in pregnant women after trachelectomy concomitant with the anatomical loss of cervical glands. Post-trachelectomy women delivered at term when MUC5B/AC abundance was greater than the mean normalized abundance of the control. MUC5B levels in the cervix were increased during pregnancy in both humans and mice. MUC5B mRNA was increased by addition of estradiol in human cervical epithelial cells, whereas MUC5AC was not. In a pregnant mouse model of ascending infection, E. coli was trapped in the MUC5B/AC-expressing mucin of the cervix, and neutrophils were colocalized there., Conclusion: Endocervical MUC5B and MUC5AC may be barriers to ascending pathogens during pregnancy., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Context: Placental dysfunction is the underlying cause of common major disorders of pregnancy, such as fetal growth restriction and preeclampsia. However, the mechanisms of placental dysfunction are not entirely elucidated. We previously reported 10 reliable preeclampsia pathways based on multiple microarray data sets, among which was the sonic hedgehog (SHH) pathway. In this study, we describe the significant role of SHH signaling involved in placental development and fetal growth., Design: The placental expression levels of surrogate markers of the SHH pathway, patched homolog 1 (PTCH1) and glioma-associated oncogene homolog (GLI) 2, were evaluated using quantitative real-time PCR, western blot analysis, and immunohistochemistry. We investigated the underlying mechanisms of the SHH pathway in trophoblast syncytialization, a critical process for placental development and maturation, using primary cytotrophoblasts. Moreover, the potential roles of placental SHH signaling in the regulation of the IGF axis were explored by pathway analysis of microarray data. Finally, the influence of SHH signaling on fetal growth was examined by placental administration of cyclopamine, an SHH pathway inhibitor, to pregnant mice., Results: The SHH pathway was downregulated in preeclampsia placentas, and its activation was highly correlated with birth weight. Trophoblast syncytialization was modulated by noncanonical SHH-adenylate cyclase (ADCY) signaling rather than canonical SHH-GLI signaling. The IGF1 receptor pathway was regulated by both noncanonical SHH-ADCY signaling and canonical SHH-GLI signaling. Inhibition of placental SHH signaling significantly reduced fetal weight in mice., Conclusion: Placental development and fetal growth were regulated through the SHH pathway via the IGF axis., (Copyright © 2019 Endocrine Society.)

Context: Nrf2 is a key transcription factor that modulates cell defense mechanisms against endogenous and exogenous stress. Previously, we reported that thrombin increased matrix metalloproteinases and prostaglandin synthesis in human amnion mesenchymal cells., Objective: We sought to determine whether activation of Nrf2 alters the effect of thrombin on prostaglandin synthesis, protease activation, and cytokine release in human amnion. Furthermore, we analyzed the effect of Nrf2 activation on thrombin-induced preterm labor in mice., Design: Primary human amnion mesenchymal cells and pregnant mice were employed to investigate the effect of Nrf2 on thrombin-induced inflammation and preterm birth., Setting: This was a laboratory-based study using cells and mice., Results: As expected, thrombin increased cyclooxygenase-2, IL-1β, IL-6, IL-8, and matrix metalloproteinase-1 in amnion mesenchymal cells. Preincubation with Nrf2 activators, diethyl maleate or 15-deoxy-Δ12, 14-prostaglandin J2 (15d-PGJ2), profoundly repressed thrombin-induced gene expression. In addition, Nrf2 activation inhibited thrombin-induced cyclooxygenase-2 protein levels and secretion of prostaglandin E2, IL-1β, IL-6, IL-8, TNFα, and granulocyte-macrophage colony-stimulating factor in the media. Whereas vehicle and 15d-PGJ2 did not alter gestational length, all pregnant mice treated with thrombin delivered preterm. 15d-PGJ2 delayed thrombin-induced preterm birth significantly., Conclusions: The results indicate that Nrf2 activation represents a key stress response in amnion mesenchyme cells and in pregnant mice to mitigate the adverse proinflammatory effects of thrombin on the fetal membranes. We suggest, therefore, that pharmacological activation of Nrf2 may prevent the increased risk of preterm premature rupture of the membranes associated with thrombin activation that accompanies subchorionic hemorrhage or bleeding during pregnancy.

Context: Circulating endothelial cells (CECs) and progenitor cells (CEPs) have been intensively studied as a promising tool for treating ischemic diseases and monitoring cancer treatments, but how the menstrual cycle affects the variation in their counts remains unclear., Objective: The aims of the study were to determine the influence of the menstrual cycle on the number of CECs and CEPs and to investigate the association of their counts with circulating hormones and angiogenesis-associated factors., Design: CEP and CEC counts by flow cytometry and the CellSearch system and circulating factor levels were measured eight times during the menstrual cycle in 18 volunteers. The menstrual cycle was divided into six phases based on hormone concentrations., Results: CEP counts peaked in the periovulatory and middle luteal phases with a drop in the early luteal phase. CEC counts showed no significant variation. There were significant correlations between the CEP counts and the serum concentrations of estradiol (E2), LH, and granulocyte colony-stimulating factor (G-CSF) (P < 0.0001, P < 0.0001, and P = 0.01, respectively). The difference in CEP counts between two adjacent phases was significantly correlated with that in E2, LH, G-CSF, and serum vascular endothelial growth factor (P < 0.0001, P < 0.0001, P = 0.02, and P = 0.006, respectively)., Conclusion: CEP counts peaked in the periovulatory and middle luteal phases, with a drop in the early luteal phase, and were correlated with serum E2, LH, and G-CSF concentrations. Consideration of the variation in CEP counts would be important for the clinical application of CEPs.

Context: Serum concentration of oxidized low-density lipoprotein (oxLDL) is higher in women with preeclampsia than in normal pregnant woman. Lectin-like oxLDL receptor-1 (LOX-1) is one of the scavenger receptors for oxLDL and is abundantly expressed in placenta. It is well known that oxLDL activates nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulator of antioxidant and cytoprotective genes such as heme oxygenase-1 (HO-1), which play an important role in preeclampsia. However, it has yet to be elucidated whether LOX-1, along with Nrf2, participates in the pathology of preeclampsia., Objective: The objective of the study was to assess LOX-1 expression and Nrf2 activation in preeclamptic placentas and to manifest their physiological roles in preeclampsia., Methods: Expression and regulation of LOX-1, HO-1, and Nrf2 were evaluated by real-time quantitative RT-PCR and Western blotting. The functions of LOX-1 and Nrf2 were examined using an anti-LOX-1 antibody and Nrf2 activator in JAR, a choriocarcinoma cell line, and placental explants., Results: Both LOX-1 expression and Nrf2 activation were significantly decreased in preeclamptic placentas compared with normal controls. A significant decrease in LOX-1 mRNA was found in placental explant cultures under hypoxic conditions. Activation of Nrf2 up-regulated HO-1 in both the JAR cells and placental explants. Furthermore, oxLDL increased HO-1 mRNA, whereas the blockade of LOX-1 inhibited the increase of HO-1 mRNA in JAR cells., Conclusion: Decreasing LOX-1 expression in preeclamptic placenta may contribute to high oxLDL concentration, low Nrf2 activation, and low HO-1 expression. These findings provide novel insights into the crucial role of LOX-1 and Nrf2 in the pathogenesis of preeclampsia.