The Role of Progesterone and a Novel Progesterone Receptor, Progesterone Receptor Membrane Component 1, in the Inflammatory Response of Fetal Membranes to Ureaplasma parvum Infection

Progesterone modulates extracellular heat-shock proteins and interlukin-1β in human choriodecidual after Escherichia coli infection

INTRODUCTION

Chorioamnionitis is an adverse condition in human pregnancy caused by many bacterial pathogens including Escherichia coli (E. coli); which has been associated with higher risk of preterm birth. We recently reported that human maternal decidua (MDec) tissue responds to E. coli infection by secreting extracellular heat-shock proteins (eHsp)-60, -70 and interlukin-1β (IL-1β). Previous studies have shown that progesterone (P4) regulates the immune response, but it is unknown whether P4 inhibits the secretion of eHsp. The aim of this investigation was to determine the role of P4 on the secretion of eHsp-27, -60, -70 and IL-1β in MDec after 3, 6, and 24 h of E. coli infection.

METHODS

Nine human feto-maternal interface (HFMi) tissues were included and mounted in the Transwell culture system. Only the maternal decidua (MDec) was stimulated for 3, 6 and 24 h with E. coli alone or in combination with progesterone and RU486. After each treatment, the HFMi tissue was recovered to determine histological changes and the culture medium recovered to evaluate the levels of eHsp-27, -60, -70 and IL-1β by ELISA and mRNA expression by RT-PCR.

RESULTS

No structural changes were observed in the HFMi tissue treated with P4 and RU486. However, stimulation with E. coli produces diffuse inflammation and ischemic necrosis. E. coli induced infection decreases, in time- and dose-dependent manner, eHsp-27 and increases eHsp-60, eHsp-70 and IL-1β levels. In contrast, incubation of HFMi tissue with E. coli + P4 reversed eHsp and IL-1β secretion levels relative to E. coli stimulation group but not relative to the control group. The same profile was observed on the expression of eHsp-27 and eHsp-60.

DISCUSSION

we found that progesterone modulates the anti-inflammatory (eHsp-27) and pro-inflammatory (eHsp-60 and eHsp-70) levels of eHsp induced by E. coli infection in human choriodecidual tissue. eHsp-60 and eHsp-70 levels were not completely reversed; maintaining the secretion of IL-1β, which has been associated with adverse events during pregnancy.

Matrix metalloproteinases in preterm prelabor rupture of membranes in the setting of chorioamnionitis: A scoping review

Fetal or gestational membranes extend from the placenta to enclose the fetus and amniotic fluid. While the membranes spontaneously rupture at term in normal pregnancies, they can rupture prematurely before the onset of labor, termed preterm prelabor rupture of membranes (PPROM). PPROM can be triggered by bacterial infection or sterile inflammation in the membranes, known as chorioamnionitis (CAM). The membranes derive their tensile strength from a collagen-rich extracellular matrix (ECM); as such, understanding the enzymes and processes that can degrade the membrane ECM are of paramount importance. Matrix metalloproteinases (MMPs) are a class of enzymes capable of degrading collagen and other components of the ECM, and can be induced by inflammation. We used a scoping review to address the question of how MMP activity is associated with PPROM, particularly their induction due to sterile or nonsterile CAM. We have found that the most studied MMPs in PPROM were MMPs 2, 8, and 9. Additionally, some MMPs are constitutively active, while others are induced by inflammation. Mechanistic studies of the pathways that induce MMP activation are sparse, and this area is ripe for future studies. Targeting MMP activation could be a future strategy to delay or prevent PPROM.

The Role of Innate Immune System in the Human Amniotic Membrane and Human Amniotic Fluid in Protection Against Intra-Amniotic Infections and Inflammation

Intra-amniotic infection and inflammation (IAI) affect fetal development and are highly associated with preterm labor and premature rupture of membranes, which often lead to adverse neonatal outcomes. Human amniotic membrane (hAM), the inner part of the amnio-chorionic membrane, protects the embryo/fetus from environmental dangers, including microbial infection. However, weakened amnio-chorionic membrane may be breached or pathogens may enter through a different route, leading to IAI. The hAM and human amniotic fluid (hAF) respond by activation of all components of the innate immune system. This includes changes in 1) hAM structure, 2) presence of immune cells, 3) pattern recognition receptors, 4) cytokines, 5) antimicrobial peptides, 6) lipid derivatives, and 7) complement system. Herein we provide a comprehensive and integrative review of the current understanding of the innate immune response in the hAM and hAF, which will aid in design of novel studies that may lead to breakthroughs in how we perceive the IAI.

Deciphering the Role of PGRMC1 During Human Decidualization Using an In Vitro Approach

CONTEXT

Non-classical membrane progesterone receptor (mPRs) and progesterone receptor membrane component 1 (PGRMC1) expression have been detected in endometrium, but their role in decidualization had not yet been investigated. We previously demonstrated PGRMC1 downregulation in receptive endometrium and that its overexpression inhibits decidualization. Furthermore, during decidualization, PGRMC1 mainly interacts with proteins involved in biosynthesis, intracellular transport, and mitochondrial activity.

OBJECTIVE

To determine PGRMC1 and mPRs signaling role during decidualization.

METHODS

Isolated primary endometrial stromal cells (EnSC) were decidualized in vitro in the presence of classic stimuli (E2 + P4), PGRMC1 inhibitor (AG205), or membrane-impermeable P4 (P4-BSA). Endometrial biopsies were obtained from 19 fertile oocyte donors attending the IVI-Valencia in vitro fertilization (IVF) clinic. EnSC decidualization was evaluated by prolactin ELISA and F-actin immunostaining. Progesterone receptor localization was evaluated by immunofluorescence. EnSC transcriptomic profiles were analyzed by microarray technology.

RESULTS

PGRMC1 inhibition during EnSC decidualization (AG205dEnSC) does not interfere with EnSC cytoskeletal rearrangements and prolactin secretion. However, global transcriptional profiling revealed more differentially expressed genes in AG205dEnSC than in dEnSC, compared with nondecidualized EnSC (ndEnSC). In silico analysis showed that PGRMC1 inhibition upregulated more genes related to metabolism, molecular transport, and hormonal biosynthesis compared with control dEnSC. EnSC decidualized in the presence of P4-BSA showed a similar behavior as ndEnSC in terms of morphological features, absence of prolactin secretion, and transcriptomic pattern.

CONCLUSION

Our findings associate PGRMC1 to hormonal biosynthesis, metabolism, and vesicular transport-important cellular functions for dEnSC supporting pregnancy. Activation of membrane P4 receptor signaling alone was unable to induce downstream effects needed for proper decidualization.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

A Review of Ureaplasma diversum: A Representative of the Mollicute Class Associated With Reproductive and Respiratory Disorders in Cattle

The Mollicutes class encompasses wall-less microbes with a reduced genome. They may infect plants, insects, humans, and animals including those on farms and in livestock. Ureaplasma diversum is a mollicute associated with decreased reproduction mainly in the conception rate in cattle, as well as weight loss and decreased quality in milk production. Therefore, U. diversum infection contributes to important economic losses, mainly in large cattle-producing countries such as the United States, China, Brazil, and India. The characteristics of Mollicutes, virulence, and pathogenic variations make it difficult to control their infections. Genomic analysis, prevalence studies, and immunomodulation assays help better understand the pathogenesis of bovine ureaplasma. Here we present the main features of transmission, virulence, immune response, and pathogenesis of U. diversum in bovines.

Progestins Inhibit Interleukin-1β-Induced Matrix Metalloproteinase 1 and Interleukin 8 Expression via the Glucocorticoid Receptor in Primary Human Amnion Mesenchymal Cells

Preterm premature rupture of membranes is a leading cause of preterm births. Cytokine induced matrix metalloproteinase1 and interleukin 8 production from amnion mesenchymal cells may contribute to fetal membrane weakening and rupture. Progestins inhibit inflammation induced fetal membrane weakening but their effect on the inflammatory response of amnion mesenchymal cells is unknown. This study was designed to determine the role of progesterone receptor membrane component 1 and the glucocorticoid receptor in mediating the effects of progestins on interleukin-1β induced matrix metalloproteinase 1 and interleukin-8 expression in human amnion mesenchymal cells. Primary amnion mesenchymal cells harvested from human fetal membranes were passaged once and treated with vehicle, progesterone or medroxyprogesterone acetate at 10-6 M for 1 h followed by stimulation with interleukin-1β at 1 ng/ml for 24 h. Medroxyprogesterone acetate but not progesterone inhibited interleukin-1β-induced interlukin-8 and matrix metalloproteinase 1 mRNA expression. In subsequent dose response studies, medroxyprogesterone acetate, but not progesterone, at doses of 10-6-10-8 M inhibited interleukin-1β induced interleukin-8 and matrix metalloproteinase 1 mRNA expression. We further demonstrated that inhibition of glucocorticoid receptor expression, but not progesterone receptor membrane component 1 knockdown with small interfering RNA transfection, resulted in a reversal in medroxyprogesterone acetate's (10-7 M) inhibition of interleukin-1β- induced matrix metalloproteinase 1 mRNA expression and interleukin-8 mRNA expression and protein expression. Our findings demonstrate that medroxyprogesterone acetate exerts its anti-inflammatory effect primarily through the glucocorticoid receptor in human amnion mesenchymal cells. Modulation of glucocorticoid receptor signaling pathways maybe a useful therapeutic strategy for preventing inflammation induced fetal membrane weakening leading to preterm premature rupture of membranes.

Recent clinical relevance of mono-genital colonization/infection by Ureaplasma parvum

Ureaplasma parvum is the most prevalent genital mycoplasma in women of childbearing age. There is debate around the relevance of its presence in male or female genitals for disease development and as a cofactor. The objective of this study was to determine the prevalence of colonization/infection by U. parvum and its possible relationship with reproductive tract infections. We retrospectively analyzed the presence of U. parvum in patients referred by specialist clinicians for suspicion of genitourinary tract infection. U. parvum was detected in 23.8% of samples, significantly more frequently in females (39.9%) than in males (6%). Among the males, U. parvum was found alone in 68.4% of episodes, with Ct < 30. Among the females, U. parvum was detected in 88.6% of cases, with Ct < 30, including 22 cases with premature rupture of membranes and 6 cases with threat of preterm labor. Co-infection was significantly more frequent in females (62.6%) than in males (31.6%). Given the high prevalence of U. parvum as sole isolate in males and females with genitourinary symptoms, it should be considered in the diagnosis and treatment of genital infections, although its pathogenic role in some diseases has not been fully elucidated.

Decreased expression of progesterone receptor membrane component 1 in fetal membranes with chorioamnionitis among women with preterm birth

PURPOSE

Progesterone receptor membrane component 1 (PGRMC1) have anti-inflammatory and anti-apoptotic properties. This study aimed to determine the expression of PGRMC1 in fetal membranes among women with preterm labor (PTL), preterm premature rupture of membranes (PPROM), and acute histologic chorioamnionitis (HCA) during preterm birth.

METHODS

Full thickness fetal membranes were obtained from women with gestational age-matched (32-34 weeks of gestational age), and categorized as PTL without HCA (PTL, n = 10), PPROM without HCA (PPROM, n = 10), PPROM with HCA (HCA, n = 10), and term without labor and HCA (term birth (TB), n = 9). The expression of PGRMC1 was assessed using western blot and Immunohistochemistry (IHC). As CD14 is a component of the innate immune system during inflammation, CD14 was used as inflammatory indicator. Nonparametric statistics were used for analysis.

RESULTS

PGRMC1 expression for all of preterm birth was lower than in TB (P = 0.01). In HCA, PGRMC1 expression was significantly decreased compared to that in PTL and PPROM (P = 0.006. P = 0.001, respectively). PGRMC1 expression in PPROM was higher than that in PTL (P = 0.002). There was a negative correlation between PGRMC1 and CD 14/β-actin ratio (r = - 0.518; P = 0.002). IHC showed that PGRMC1 was predominant in the cytoplasm of cells, these results were consistent with those of the western blot analysis.

CONCLUSION

Preterm birth with PTL, PPROM, and especially HCA is associated with a decreased PGRMC1 in fetal membranes and inversely associated with increased CD 14.

Initiation of human parturition: signaling from senescent fetal tissues via extracellular vesicle mediated paracrine mechanism

A better understanding of the underlying mechanisms by which signals from the fetus initiate human parturition is required. Our recent findings support the core hypothesis that oxidative stress (OS) and cellular senescence of the fetal membranes (amnion and chorion) trigger human parturition. Fetal membrane cell senescence at term is a natural physiological response to OS that occurs as a result of increased metabolic demands by the maturing fetus. Fetal membrane senescence is affected by the activation of the p38 mitogen activated kinase-mediated pathway. Similarly, various risk factors of preterm labor and premature rupture of the membranes also cause OS-induced senescence. Data suggest that fetal cell senescence causes inflammatory senescence-associated secretory phenotype (SASP) release. Besides SASP, high mobility group box 1 and cell-free fetal telomere fragments translocate from the nucleus to the cytosol in senescent cells, where they represent damage-associated molecular pattern markers (DAMPs). In fetal membranes, both SASPs and DAMPs augment fetal cell senescence and an associated ‘sterile’ inflammatory reaction. In senescent cells, DAMPs are encapsulated in extracellular vesicles, specifically exosomes, which are 30–150 nm particles, and propagated to distant sites. Exosomes traffic from the fetus to the maternal side and cause labor-associated inflammatory changes in maternal uterine tissues. Thus, fetal membrane senescence and the inflammation generated from this process functions as a paracrine signaling system during parturition. A better understanding of the premature activation of these signals can provide insights into the mechanisms by which fetal signals initiate preterm parturition.

Progestin therapy to prevent preterm birth: History and effectiveness of current strategies and development of novel approaches

In the 1930s the "progestin" hormone produced by the corpus luteum was isolated and found to be a Δ⁴-keto-steroid. It was aptly named progesterone (P4) and in the following 30 years the capacity of P4 and derivatives to prevent preterm birth (PTB) was examined. Outcomes of multiple small studies suggested that progestin prophylaxis beginning at mid-gestation decreases the risk for PTB. Subsequent larger trials found that prophylaxis with weekly intramuscular injections of 17α-hydroxyprogesterone caproate (17HPC) beginning at mid-gestation decreased PTB risk in women with a history of PTB. Other trials found that daily vaginal P4 prophylaxis, also beginning at mid-gestation decreased PTB risk in women with a short cervix. Currently, prophylaxis with 17HPC (in women with a history of PTB) or vaginal P4 (in women with a short cervix) are used to prevent PTB. Recent advances in understanding the molecular biology of P4 signaling in uterine cells is revealing novel progestin-based targets for PTB prevention. One possibility is to use selective P4 receptor (PR) modulators (SPRMs) to boost PR anti-inflammatory activity that blocks labor, while simultaneously preventing PR phosphorylation that causes loss of P4/PR anti-inflammatory activity. This may be achieved by SPRMs that induce a specific PR conformation that prevents site-specific serine phosphorylation that inhibits anti-inflammatory activity. Further advances in understanding how P4 promotes uterine quiescence and how its labor blocking actions are withdrawn to trigger parturition will reveal novel therapeutic targets to more effectively prevent PTB.

Progestins Inhibit Tumor Necrosis Factor α-Induced Matrix Metalloproteinase 9 Activity via the Glucocorticoid Receptor in Primary Amnion Epithelial Cells

Progestins have been recommended for preterm birth prevention in high-risk women; however, their mechanism of action still remains an area of debate. Medroxyprogesterone acetate (MPA) has previously been shown to significantly inhibit tumor necrosis factor α (TNFα)-induced matrix metalloproteinase 9 (MMP9) messenger RNA (mRNA) expression and activity in primary amnion epithelial cells, a process that may lead to preterm premature rupture of membranes. A mechanism that explains MPA's inhibition of TNFα-induced MMP9 mRNA expression and activity in primary amnion epithelial cells is unclear since these cells lack the classic nuclear progesterone receptor but express a membrane-associated progesterone receptor-progesterone receptor membrane component 1 (PGRMC1) along with the glucocorticoid receptor (GR). Primary amnion epithelial cells harvested from healthy term pregnant women at cesarean section were treated with PGRMC1 (to knockdown PGRMC1 expression), GR (to knockdown GR expression), or control small interfering RNA (siRNA; 10 nm) for 72 hours, pretreated with ethanol or MPA (10^-6 M) for 6 hours, and then stimulated with or without TNFα 10 ng/mL for 24 hours. Real-time quantitative polymerase chain reaction and gelatin zymography were used to quantify MMP9 mRNA expression and activity, respectively. Experimental groups were compared using 1-way analysis of variance. Both TNFα-induced MMP9 mRNA expression and activity were significantly inhibited by pretreatment with MPA; however, only the inhibition of TNFα-induced MMP9 activity was partially reversed with PGRMC1 siRNA. However, GR siRNA reversed both the inhibition of TNFα-induced MMP9 mRNA expression and activity by MPA. This study demonstrates that MPA mediates its anti-inflammatory effects primarily through GR and partially through PGRMC1 in primary amnion epithelial cells.

Infection-induced thrombin production: a potential novel mechanism for preterm premature rupture of membranes (PPROM)

BACKGROUND

Preterm premature rupture of membranes is a leading contributor to maternal and neonatal morbidity and death. Epidemiologic and experimental studies have demonstrated that thrombin causes fetal membrane weakening and subsequently preterm premature rupture of membranes. Although blood is suspected to be the likely source of thrombin in fetal membranes and amniotic fluid of patients with preterm premature rupture of membranes, this has not been proved. Ureaplasma parvum is emerging as a pathogen involved in prematurity, which includes preterm premature rupture of membranes; however, until now, prothrombin production that has been induced directly by bacteria in fetal membranes has not been described.

OBJECTIVE

This study was designed to investigate whether Ureaplasma parvum exposure can induce prothrombin production in fetal membranes cells.

STUDY DESIGN

Primary fetal membrane cells (amnion epithelial, chorion trophoblast, and decidua stromal) or full-thickness fetal membrane tissue explants from elective, term, uncomplicated cesarean deliveries were harvested. Cells or tissue explants were infected with live Ureaplasma parvum (1×10⁵, 1×10⁶ or 1×10⁷ colony-forming units per milliliter) or lipopolysaccharide (Escherichia coli J5, L-5014; Sigma Chemical Company, St. Louis, MO; 100 ng/mL or 1000 ng/mL) for 24 hours. Tissue explants were fixed for immunohistochemistry staining of thrombin/prothrombin. Fetal membrane cells were fixed for confocal immunofluorescent staining of the biomarkers of fetal membrane cell types and thrombin/prothrombin. Protein and messenger RNA were harvested from the cells and tissue explants for Western blot or quantitative reverse transcription polymerase chain reaction to quantify thrombin/prothrombin protein or messenger RNA production, respectively. Data are presented as mean values ± standard errors of mean. Data were analyzed using 1-way analysis of variance with post hoc Dunnett's test.

RESULTS

Prothrombin production and localization were confirmed by Western blot and immunostainings in all primary fetal membrane cells and tissue explants. Immunofluorescence observations revealed a perinuclear localization of prothrombin in amnion epithelial cells. Localization of prothrombin in chorion and decidua cells was perinuclear and cytoplasmic. Prothrombin messenger RNA and protein expression in fetal membranes were increased significantly by Ureaplasma parvum, but not lipopolysaccharide, treatments in a dose-dependent manner. Specifically, Ureaplasma parvum at a dose of 1×10⁷ colony-forming units/mL significantly increased both prothrombin messenger RNA (fold changes in amnion: 4.1±1.9; chorion: 5.7±4.2; decidua: 10.0±5.4; fetal membrane: 9.2±3.0) and protein expression (fold changes in amnion: 138.0±44.0; chorion: 139.6±15.1; decidua: 56.9±29.1; fetal membrane: 133.1±40.0) compared with untreated control subjects. Ureaplasma parvum at a dose of 1×10⁶ colony-forming units/mL significantly up-regulated prothrombin protein expression in chorion cells (fold change: 54.9±5.3) and prothrombin messenger RNA expression in decidua cells (fold change: 4.4±1.9).

CONCLUSION

Our results demonstrate that prothrombin can be produced directly by fetal membrane amnion, chorion, and decidua cells. Further, prothrombin production can be stimulated by Ureaplasma parvum exposure in fetal membranes. These findings represent a potential novel underlying mechanism of Ureaplasma parvum-induced rupture of fetal membranes.

Effect of Genital Sampling Site on the Detection and Quantification of Ureaplasma Species with Quantitative Polymerase Chain Reaction during Pregnancy

Objective. This study aimed to compare the qualitative and quantitative reproducibility of quantitative PCR (qPCR) for Ureaplasma species (Ureaplasma spp.) throughout pregnancy and according to the genital sampling site. Study Design. Between 5 and 14 weeks of gestation (T1), vaginal, fornix, and two cervical samples were taken. Sampling was repeated during the 2nd (T2) and 3rd (T3) trimester in randomly selected T1 positive and negative women. Qualitative and quantitative reproducibility were evaluated using, respectively, Cohen's kappa (κ) and interclass correlation coefficients (ICC) and repeated measures ANOVA on the log-transformed mean number of DNA copies for each sampling site. Results. During T1, 51/127 women were positive for U. parvum and 8 for U. urealyticum (4 patients for both). Sampling was repeated for 44/55 women at T2 and/or T3; 43 (97.7%) remained positive at the three timepoints. κ ranged between 0.83 and 0.95 and the ICC for cervical samples was 0.86. Conclusions. Colonization by Ureaplasma spp. seems to be very constant during pregnancy and vaginal samples have the highest detection rate.