Heme metabolism and HO-1 in the pathogenesis and potential intervention of endometriosis.

Endometriosis (EM) is one of the diseases related to retrograded menstruation and hemoglobin. Heme, released from hemoglobin, is degraded by heme oxygenase-1 (HO-1). In EM lesions, heme metabolites regulate processes such as inflammation, redox balance, autophagy, dysmenorrhea, malignancy, and invasion, where macrophages (Mø) play a fundamental role in their interactions. Regulation occurs at molecular, cellular, and pathological levels. Numerous studies suggest that heme is an indispensable component in EM and may contribute to its pathogenesis. The regulatory role of heme in EM encompasses cytokines, signaling pathways, and kinases that mediate cellular responses to external stimuli. HO-1, a catalytic enzyme in the catabolic phase of heme, mitigates heme's cytotoxicity in EM due to its antioxidant, anti-inflammatory, and anti-proliferative properties. Certain compounds may intervene in EM by targeting heme metabolism, guiding the development of appropriate treatments for all stages of endometriosis.

Validation of mitochondrial biomarkers and immune dynamics in polycystic ovary syndrome.

PROBLEM: Polycystic ovary syndrome (PCOS), a prevalent endocrine-metabolic disorder, presents considerable therapeutic challenges due to its complex and elusive pathophysiology. METHOD OF STUDY: We employed three machine learning algorithms to identify potential biomarkers within a training dataset, comprising GSE138518, GSE155489, and GSE193123. The diagnostic accuracy of these biomarkers was rigorously evaluated using a validation dataset using area under the curve (AUC) metrics. Further validation in clinical samples was conducted using PCR and immunofluorescence techniques. Additionally, we investigate the complex interplay among immune cells in PCOS using CIBERSORT to uncover the relationships between the identified biomarkers and various immune cell types. RESULTS: Our analysis identified ACSS2, LPIN1, and NR4A1 as key mitochondria-related biomarkers associated with PCOS. A notable difference was observed in the immune microenvironment between PCOS patients and healthy controls. In particular, LPIN1 exhibited a positive correlation with resting mast cells, whereas NR4A1 demonstrated a negative correlation with monocytes in PCOS patients. CONCLUSION: ACSS2, LPIN1, and NR4A1 emerge as PCOS-related diagnostic biomarkers and potential intervention targets, opening new avenues for the diagnosis and management of PCOS.

Accumulation of γδT cells in the decidua is promoted by RANKL which upregulates ICAM-1 via NF-κB.

In brief: The mechanism underlying the accumulation of γδT cells in the decidua, which helps maintain maternal-fetal immunotolerance in early pregnancy, is unknown. This study reveals that DSC-derived RANKL upregulates ICAM-1 expression via the NF-κB pathway to enable γδT cell accumulation in the early decidua. Abstract: Decidual γδT (dγδT) cells help maintain maternal-fetal immunotolerance in early pregnancy. However, the mechanism underlying the accumulation of γδT cells in the decidua is unknown. Previous work showed that RANKL upregulated intercellular adhesion molecule 1 (ICAM-1) in decidual stromal cells (DSCs), and Rankl knockout mice had limited dγδT cell populations. In this study, we measured the expression levels of RANKL/RANK and ICAM-1 in DSCs, in addition to the integrins of ICAM-1 on dγδT cells, and the number of dγδT cells from patients with recurrent spontaneous abortion (RSA) and normal pregnant women in the first trimester. RSA patients showed significantly decreased RANKL/RANK and ICAM-1/CD11a signaling in decidua, and a decreased percentage of dγδT cells, which was positively correlated with DSC-derived RANKL and ICAM-1. Next, an in vitro adhesion experiment showed that the enhanced attraction of human DSCs to dγδT cells after RANKL overexpression was almost completely aborted by anti-ICAM-1. Furthermore, Rankl knockout mice showed a significant reduction in NF-κB activity compared with wild-type controls. Finally, we applied a selective NF-κB inhibitor named PDTC to validate the role of NF-κB in RANKL-mediated ICAM-1 upregulation. Taken together, our data show that DSC-derived RANKL upregulates ICAM-1 expression via the NF-κB pathway to enable γδT cell accumulation in the early decidua. A reduction in RANKL/ICAM-1 signaling in DSCs may result in insufficient accumulation of γδT cells in decidua and, in turn, RSA.

Potential Causal Association between Plasma Metabolites, Immunophenotypes, and Female Reproductive Disorders: A Two-Sample Mendelian Randomization Analysis.

BACKGROUND: While extensive research highlighted the involvement of metabolism and immune cells in female reproductive diseases, causality remains unestablished. METHODS: Instrumental variables for 486 circulating metabolites (N = 7824) and 731 immunophenotypes (N = 3757) were derived from a genome-wide association study (GWAS) meta-analysis. FinnGen contributed data on 14 female reproductive disorders. A bidirectional two-sample Mendelian randomization study was performed to determine the relationships between exposures and outcomes. The robustness of results, potential heterogeneity, and horizontal pleiotropy were examined through sensitivity analysis. RESULTS: High levels of mannose were found to be causally associated with increased risks of gestational diabetes (GDM) (OR [95% CI], 6.02 [2.85-12.73], p = 2.55 × 10-6). A genetically predicted elevation in the relative count of circulating CD28-CD25++CD8+ T cells was causally related to increased female infertility risk (OR [95% CI], 1.26 [1.14-1.40], p = 1.07 × 10-5), whereas a high absolute count of NKT cells reduced the risk of ectopic pregnancy (OR [95% CI], 0.87 [0.82-0.93], p = 5.94 × 10-6). These results remained consistent in sensitivity analyses. CONCLUSIONS: Our study supports mannose as a promising GDM biomarker and intervention target by integrating metabolomics and genomics.

Novel Insights into Prokineticin 1 Role in Pregnancy-related Diseases.

Prokineticin 1 (PROK1) is a secreted protein involved in a range of physiological activities such as cell proliferation, migration, angiogenesis, and neuronal cell proliferation. Emerging evidences show that PROK1/PROK receptors (PROKRs) are expressed by trophoblasts, and decidual stroma cells at the maternal-fetal interface. PROK1 plays a critical role in successful pregnancy establishment by regulating the decidualization, implantation and placental development. Dysregulation of prokineticin signaling has been described in certain pathological states associated with pregnancy, including pre-eclampsia, recurrent miscarriage and fetal growth restriction. In this review, the expression and pleiotropic roles of PROK1 under physiological and pathological pregnancy conditions are discussed.

Current advancements in diagnosing and managing cavovarus foot in paediatric patients.

The cavovarus deformity is a pathological condition characterised by an anomalous elevation of the longitudinal arch. This condition results from a significant hindfoot varus and forefoot equinus deformity. This phenomenon comprises diverse anomalies and therapies and exhibits a prevalence of 25% within the populace. A thorough clinical evaluation is required to identify deformities in the cavovarus foot. Weight-bearing radiographs play a crucial role in identifying the apex of deformity and quantifying the required extent of correction. Cavus feet are frequently linked with neurological conditions affecting sensory and motor nerves. Identifying the optimal treatment for individual patients necessitates the performance of clinical and radiographic evaluations. Inaccurate diagnosis of a neurological disorder can lead to inappropriate surgical intervention, relapse, and inadequate reconstruction. When faced with progressive anomalies, it is crucial to implement a phased surgical protocol promptly to avoid exacerbating malalignment. Various surgical procedures have been recorded, including soft tissue releases, tendon transfers, osteotomies, and arthrodesis, which are selected based on the nature and extent of the deformity assessment findings, with the ultimate goal of reaching a foot that is both plantigrade and balanced. Due to a lack of research on this topic, the present review aims to furnish the most recent literature update on the manifestation, imaging evaluation, and optimal therapeutic interventions currently accessible for individuals afflicted with cavovarus deformities and to assist healthcare providers in selecting the most suitable therapy for paediatric patients with this condition in their routine clinical practice.

Chitosan alleviates ovarian aging by enhancing macrophage phagocyte-mediated tissue homeostasis.

BACKGROUND: Age-related changes in the ovarian microenvironment are linked to impaired fertility in women. Macrophages play important roles in ovarian tissue homeostasis and immune surveillance. However, the impact of aging on ovarian macrophage function and ovarian homeostasis remains poorly understood. METHODS: Senescence-associated beta-galactosidase staining, immunohistochemistry, and TUNEL staining were used to assess senescence and apoptosis, respectively. Flow cytometry was employed to evaluate mitochondrial membrane potential (MMP) and apoptosis in granulosa cells lines (KGN), and macrophages phagocytosis. After a 2-month treatment with low molecular weight Chitosan (LMWC), ovarian tissues from mice were collected for comprehensive analysis. RESULTS: Compared with the liver and uterus, the ovary displayed accelerated aging in an age-dependent manner, which was accompanied by elevated levels of inflammatory factors and apoptotic cells, and impaired macrophage phagocytic activity. The aged KGN cells exhibited elevated reactive oxygen species (ROS) and apoptotic levels alongside decreased MMP. H2O2-induced aging macrophages showed reduced phagocytosis function. Moreover, there were excessive aging macrophages with impaired phagocytosis in the follicular fluid of patients with diminished ovarian reserve (DOR). Notably, LMWC administration alleviated ovarian aging by enhancing macrophage phagocytosis and promoting tissue homeostasis. CONCLUSIONS: Aging ovarian is characterized by an accumulation of aging and apoptotic granulosa cells, an inflammatory response and macrophage phagocytosis dysfunction. In turn, impaired phagocytosis of macrophage contributes to insufficient clearance of aging and apoptotic granulosa cells and the increased risk of DOR. Additionally, LMWC emerges as a potential therapeutic strategy for age-related ovarian dysfunction.

Recent Advances in Folates and Autoantibodies against Folate Receptors in Early Pregnancy and Miscarriage.

Though firstly identified in cerebral folate deficiency, autoantibodies against folate receptors (FRAbs) have been implicated in pregnancy complications such as miscarriage; however, the underlying mechanism needs to be further elaborated. FRAbs can be produced via sensitization mediated by folate-binding protein as well as gene mutation, aberrant modulation, or degradation of folate receptors (FRs). FRAbs may interfere with folate internalization and metabolism through blocking or binding with FRs. Interestingly, different types of FRs are expressed on trophoblast cells, decidual epithelium or stroma, and macrophages at the maternal-fetal interface, implying FRAbs may be involved in the critical events necessary for a successful pregnancy. Thus, we propose that FRAbs may disturb pregnancy establishment and maintenance by modulating trophoblastic biofunctions, placental development, decidualization, and decidua homeostasis as well as the functions of FOLR2+ macrophages. In light of these findings, FRAbs may be a critical factor in pathological pregnancy, and deserve careful consideration in therapies involving folic acid supplementation for pregnancy complications.

The Relationship between Cadmium Exposure and Mortality in Postmenopausal Females: A Cohort Study of 2001-2018 NHANES.

Cadmium is one of the most harmful elements to human health, and the health of postmenopausal females is an important public health issue. However, the correlation between exposure to cadmium and the survival status of postmenopausal women is currently not fully clear. This research intended to explore the correlation between cadmium exposure and mortality among postmenopausal females using a representative sample of the population in the U.S. We drew upon the data of the National Health and Nutrition Examination Survey (2001-2018). Cox's proportional hazards models and a restricted cubic spline regression (RCS) model were utilized to analyze the correlation between blood and urine cadmium and the mortality of postmenopausal women. Stratified analyses also were conducted to identify the highest risk factor of mortality for the participants. The mean concentration of blood cadmium was 0.59 µg/L, and the mean concentration of urine cadmium was 0.73 µg/g creatinine. Higher cadmium concentrations in blood and urine were significantly related to an increase in all-cause mortality for postmenopausal females after adjustment for multivariate covariates. Furthermore, there was a linear positive correlation between urine cadmium concentrations and cancer mortality, while there was no correlation between blood cadmium and cancer death. The correlation between cadmium concentrations and all-cause mortality is stronger in older, more overweight women with a history of hypertension or smoking. We propose that cadmium remains an important risk factor of all-cause and cancer mortality among postmenopausal females in the U.S. Further decreases in cadmium exposure in the population can promote the health of postmenopausal women and prolong their lifespan.

Association of serum 25-hydroxyvitamin D levels with all-cause and cause-specific mortality among postmenopausal females: results from NHANES.

BACKGROUND: Vitamin D deficiency is common among the population, but its relationship with mortality of postmenopausal females is unclear. The aim of this study is to explore the association between serum 25-Hydroxyvitamin D (25(OH)D) and all-cause and cause-specific mortality among postmenopausal women in the United States. METHODS: 6812 participants of postmenopausal females from the National Health and Nutrition Examination Survey (2001-2018) were included in this study. The mortality status of the follow-up was ascertained by linkage to National Death Index (NDI) records through 31 December 2019. We used cox proportional hazards models to estimate the association of serum 25(OH)D concentrations and mortality of postmenopausal females. RESULTS: The mean level of serum 25(OH)D was 72.57 ± 29.93 nmol/L, and 65.34% had insufficient vitamin D. In postmenopausal females, low serum 25(OH)D concentrations were significantly associated with higher levels of glycohemoglobin, glucose, and lower levels of HDL. During follow-up, 1448 all-cause deaths occurred, including 393 cardiovascular disease (CVD)-related deaths and 263 cancer deaths. After multivariate adjustment, higher serum 25(OH)D levels were significantly related with lower all-cause and CVD mortality. In addition, serum 25(OH)D presented a L-shaped relationship with all-cause mortality, while appeared a U-shaped with CVD mortality, and the cut-off value is 73.89 nmol/L and 46.75 nmol/L respectively. CONCLUSIONS: Low serum 25(OH)D levels are associated with the higher risk of all-cause and CVD mortality in postmenopausal females. These findings provide new ideas and targets for the health management of postmenopausal women.

An abnormal LPA/LPAR1-NHE1 axis leads to the autophagy deficiency of trophoblast cells in recurrent spontaneous abortion.

In brief: Autophagy is important for trophoblast cells at the maternal-fetal interface during early pregnancy. This study suggests that trophoblast cells can promote the autophagy under a regulation of the LPA/LPAR 1-NHE1 axis. Abstract: The autophagy of trophoblasts is necessary for developing and maintaining a healthy pregnancy. Autophagy dysfunction in trophoblast cells is linked to recurrent spontaneous abortion (RSA). However, the mechanism underlying trophoblast autophagy is unknown. In this study, we investigated the expression of autophagy-related genes in both normal and RSA villi. We also examined the production of LPA and LPAR1 in trophoblast cells during early pregnancy. We found that the activation of the LPA-LPAR1 axis triggered the autophagy of trophoblast cells and increased the expression of NHE1. Inhibition of NHE1 suppressed the autophagy in trophoblast cells and we confirmed that NHE1 regulates LPA production in trophoblast cells. Additionally, we found decreased expression of autophagy-related genes and LPAR1 in villi from RSA patients. These observations indicate that the LPA/LPAR1-NHE1 axis regulates the autophagy of trophoblast cells during pregnancy. Insufficient autophagy and poor expression of LPAR1 in trophoblast cells may result in the dysfunction of the trophoblasts and an increased risk of spontaneous abortion. Overall, our research elucidated that a positive LPA/LPAR1-NHE1 axis can promote the autophagy of trophoblast cells and the abnormal axis leads to the autophagy deficiency of trophoblast cells in recurrent spontaneous abortion.

Ginsenosides in endometrium-related diseases: Emerging roles and mechanisms.

Ginsenosides, agents extracted from an important herb (ginseng), are expected to provide new therapies for endometrium-related diseases. Based on the molecular types of ginsenosides, we reviewed the main pharmacological effects of ginsenosides against endometrium-related diseases (e.g., endometrial cancers, endometriosis, and endometritis). The mechanism of action of ginsenosides involves inducing apoptosis of endometrium-related cells, promoting autophagy of endometrium-related cells, regulating epithelial-mesenchymal transition (EMT) in endometrium-related cells, and activating the immune system to kill cells associated with endometrial diseases. We hope to provide a theoretical foundation for the treatment of endometrium-related diseases by ginsenosides.

Active Estrogen-Succinate Metabolism Promotes Heme Accumulation and Increases the Proliferative and Invasive Potential of Endometrial Cancer Cells.

Uterine endometrial cancer (UEC) is an estrogen-related tumor. Succinate and heme metabolism play important roles in the progression of multiple tumors. However, the relationship between estrogen, succinate, and heme metabolism and related regulatory mechanisms remain largely unknown. In this study, we observed that the expression of aminolevulinate delta synthase 1 (ALAS1) and solute carrier family member 38 (SLC25A38) in UEC tissues is significantly higher than that in normal tissues. Further analysis showed that estrogen and succinate increased the expression of ALAS1 and SLC25A38 in uterine endometrial cancer cells (UECC), and the administration of succinate upregulated the level of the estrogen receptor (ER). Silencing nuclear receptor coactivator 1 (NCOA1) reversed the effects of estrogen and succinate via downregulation of ALAS1 expression. Additionally, exposure of UECC to heme increased cell viability and invasiveness, while silencing the NCOA1 gene weakened this effect. These findings revealed that estrogen and succinate can synergistically increase the expression of ALAS1 and SLC25A38 via the ERß/NCOA1 axis, promoting heme accumulation and increasing the proliferative and invasive potential of UECC.

Heme induced progesterone-resistant profiling and promotion of endometriosis in vitro and in vivo.

Endometriosis is an estrogen-dependent, progesterone-resistant gynecological disease with an unknown pathogenesis. Compared to women without endometriosis, women with endometriosis have a remarkably high heme level in the peritoneal fluid. To further investigate the pathomechanisms of heme in endometriosis, we aimed to identify the dysregulated expression of heme-trafficking proteins, such as PGRMC1/2 that are also receptors that mediate the non-genomic responses to progesterone, and heme-degrading enzymes between ectopic endometrial stromal cells and their normal counterparts. We found that heme could regulate progesterone receptor-related gene expression. Functional human endometrial stromal cell experiments showed that heme promotes cell proliferation and migration in a heme oxygenase-1-independent manner; moreover, blocking oxidative phosphorylation/ATP generation could abolish these effects of heme in vitro, whereas intraperitoneal hemopexin administration could alleviate heme-triggered ectopic lesions in vivo. Therefore, heme likely mediates the induction of progesterone resistance and simultaneously induces endometriosis via the mitochondrial oxidative phosphorylation pathway.

Maternal traditional Chinese medicine exposure and risk of congenital malformations: a multicenter prospective cohort study.

INTRODUCTION: The potential teratogenic risk of traditional Chinese medicine (TCM) is of widespread concern; however, related evidence is largely absent in humans. This study aimed to compare the prevalence of congenital malformations between pregnant women with and without TCM exposure. MATERIAL AND METHODS: This was a multicenter prospective cohort study of 17 713 women who participated in a survey on periconceptional TCM exposure. Primary outcome was congenital malformations diagnosed from a survey conducted on the day 42 after delivery. RESULTS: A total of 16 751 pregnant women with 273 congenital malformations were included in the analysis. Fetuses exposed to TCM had an increased risk of congenital malformations compared to those without exposure (odds ratio [OR] 2.10; 95% confidence interval [CI] 1.09-4.02) after controlling for potential confounders. There were significant associations with congenital malformations in women with early pregnant exposure (OR 2.04, 95% CI 1.00-4.20) and for those who received ≥2 TCM formulas (OR 5.84, 95% CI 1.44-23.65). Pre-pregnancy TCM exposure was significantly associated with an increased risk of congenital heart defects (OR 12.69; 95% CI 3.01-53.51). CONCLUSIONS: Periconceptional TCM exposure is associated with an increased risk of congenital malformation. This effect was cumulative and sensitive to periconceptional age. Therefore, TCM deserves more attention and should be used cautiously for pregnant women and those trying to become pregnant.

IL-27 deficiency inhibits proliferation and invasion of trophoblasts via the SFRP2/Wnt/ß-catenin pathway in fetal growth restriction.

Background: Fetal growth restriction (FGR) is characterized by restricted fetal growth and dysregulated placental development. The etiology and pathogenesis still remain elusive. IL-27 shows multiple roles in regulating various biological processes, however, how IL-27 involves in placentation in FGR pregnancy hasn't been demonstrated. Methods: The levels of IL-27 and IL-27RA in FGR and normal placentae were determined by immunohistochemistry, western blot and RT-PCR. HTR-8/SVneo cells and Il27ra-/- murine models have been adopted to evaluate the effects of IL-27 on the bio-functions of trophoblast cells. GO enrichment and GSEA analysis were performed to explore the underlying mechanism. Findings: IL-27 and IL-27RA was lowly expressed in FGR placentae and administration of IL-27 on HTR-8/SVneo could promote its proliferation, migration and invasion. Comparing with wildtypes, Il27ra-/- embryos were smaller and lighter, and the placentae from which were poorly developed. In mechanism, the molecules of canonical Wnt/ß-catenin pathway (CCND1, CMYC, SOX9) were downregulated in Il27ra-/- placentae. In contrast, the expression of SFRP2 (negative regulator of Wnt) was increased. Overexpression of SFRP2 in vitro could impair trophoblast migration and invasion capacity. Interpretation: IL-27/IL-27RA negatively regulates SFRP2 to activate Wnt/ß-catenin, and thus promotes migration and invasion of trophoblasts during pregnancy. However, IL-27 deficiency may contribute to the development of FGR by restricting the Wnt activity.

Identification of potential biomarkers and immune infiltration characteristics in recurrent implantation failure using bioinformatics analysis.

Introduction: Recurrent implantation failure (RIF) is a frustrating challenge because the cause is unknown. The current study aims to identify differentially expressed genes (DEGs) in the endometrium on the basis of immune cell infiltration characteristics between RIF patients and healthy controls, as well as to investigate potential prognostic markers in RIF. Methods: GSE103465, and GSE111974 datasets from the Gene Expression Omnibus database were obtained to screen DEGs between RIF and control groups. Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes Pathway analysis, Gene Set Enrichment Analysis, and Protein-protein interactions analysis were performed to investigate potential biological functions and signaling pathways. CIBERSORT was used to describe the level of immune infiltration in RIF, and flow cytometry was used to confirm the top two most abundant immune cells detected. Results: 122 downregulated and 66 upregulated DEGs were obtained between RIF and control groups. Six immune-related hub genes were discovered, which were involved in Wnt/-catenin signaling and Notch signaling as a result of our research. The ROC curves revealed that three of the six identified genes (AKT1, PSMB8, and PSMD10) had potential diagnostic values for RIF. Finally, we used cMap analysis to identify potential therapeutic or induced compounds for RIF, among which fulvestrant (estrogen receptor antagonist), bisindolylmaleimide-ix (CDK and PKC inhibitor), and JNK-9L (JNK inhibitor) were thought to influence the pathogenic process of RIF. Furthermore, our findings revealed the level of immune infiltration in RIF by highlighting three signaling pathways (Wnt/-catenin signaling, Notch signaling, and immune response) and three potential diagnostic DEGs (AKT1, PSMB8, and PSMD10). Conclusion: Importantly, our findings may contribute to the scientific basis for several potential therapeutic agents to improve endometrial receptivity.

Maternal expectations of fetal gender and risk of postpartum depression.

BACKGROUND: Female offspring was associated with a high risk of postpartum depression (PPD) during the one-child policy period in China. However, little is known about the association between maternal expectations on fetal gender and the risk of PPD in the context of the new two children policy implemented in 2016. METHODS: We conducted a hospital-based cohort study of women with singleton pregnancies between 2017 and 2018 (n = 991) to address this concern. Logistic regression was run to estimate the association between unexpected fetal gender and the risk of PPD. RESULTS: A total of 127 women (12.8%) were diagnosed with PPD. Compared with women who achieved fetal gender expectations, the odds ratio (OR) for PPD among those who had an unexpected fetal gender was 2.44 (95% confidence interval (CI): 1.30-4.58) (in the backward method logistic regression model) and 2.25 (95% CI: 1.21-4.18) (in the forward method model), respectively. The disparity of the association was significant among primiparous and pluriparous women (OR, 2.52, 95% CI: 1.32-4.84, P = 0.005 vs. OR, 0.91, 95% CI: 0.09-8.75, P = 0.932). Fetal gender expectations accounted for about 15% of the risk of PPD in the structural equation models. CONCLUSIONS: These results indicated that unexpected fetal gender was associated with an increased risk of PPD among Chinese primiparous women.

Hypoxia-mediated chemotaxis and residence of macrophage in decidua by secreting VEGFA and CCL2 during normal pregnancy.

In brief: Hypoxia is vital for the establishment of the maternal-fetal interface during early pregnancy. This study shows that decidual macrophages (dMφ) could be recruited and reside in decidua under the regulation of hypoxia/VEGFA-CCL2 axis. Abstract: Infiltration and residence of decidual macrophages (dMφ) are of great significance to pregnancy maintenance for their role in angiogenesis, placental development, and inducing immune tolerance. Besides, hypoxia has now been acknowledged as an important biological event at maternal-fetal interface in the first trimester. However, whether and how hypoxia regulates biofunctions of dMφ remain elusive. Herein, we observed increased expression of C-C motif chemokine ligand 2 (CCL2) and residence of macrophages in decidua compared to secretory-phase endometrium. Moreover, hypoxia treatment on stromal cells improved the migration and adhesion of dMφ. Mechanistically, these effects might be mediated by upregulated CCL2 and adhesion molecules (especially ICAM2 and ICAM5) on stromal cells in the presence of endogenous vascular endothelial growth factor-A (VEGFA) in hypoxia. These findings were also verified by recombinant VEGFA and indirect coculture, indicating that the interaction between stromal cells and dMφ in hypoxia condition may facilitate dMφ recruitment and residence. In conclusion, VEGFA derived from a hypoxic environment may manipulate CCL2/CCR2 and adhesion molecules to enhance the interactions between dMφ and stromal cells and thus contribute to the enrichment of macrophages in decidua early during normal pregnancy.

RANKL up-regulated by progesterone aggravates lipopolysaccharide-induced acute lung injury during pregnancy.

Acute lung injury (ALI) is a common acute respiratory disease with high morbidity and mortality rate in pregnant women. Receptor activator of NF-κB ligand (TNFSF11, also known as RANKL) exerts either pro-inflammatory or anti-inflammatory effects on the immune response. LPS administration reduced the survival time (n = 10, p < 0.01), increased wet/dry ratio (n = 10, p < 0.001) and lung injury score (n = 10, p < 0.001), the elevated proportions of plasmacytoid dendritic cells (pDCs) (n = 10, p < 0.0001), tissue-resident DCs (resDCs) (n = 10, p < 0.0001), macrophages (n = 10, p < 0.0001), and neutrophils (n = 10, p < 0.0001), and the expressions of costimulatory molecules and inflammation cytokines (n = 10, p < 0.05) in lungs of pregnant mice, compared with non-pregnant mice. In vitro, progesterone up-regulated the expression of RANKL (n > 6, p < 0.05) on pulmonary fibroblasts. The results of cytokine arrays showed that the cytokines associated with inflammatory response and leukocyte differentiation were decreased in pulmonary fibroblasts after treatment with anti-RANKL neutralizing antibody, compared with control pulmonary fibroblasts. More notably, we found that Tnfsf11-/- pregnant mice had longer survival durations (n = 10, p < 0.01), lower lung injury scores (n = 10, p < 0.05), and lower immune cell infiltration (n = 10, p < 0.05). These data imply that the RANKL/RANK axis plays an essential role in LPS-induced ALI during pregnancy possibly through a variety of pathways.