Current findings in endometrial microbiome: impact on uterine diseases

Microbiome or microbiota is essential to regulate many mammalian physiological processes, including reproduction. Like other organs or tissues, the upper female reproductive tract (FRT) used to be considered devoid of microorganisms; however, a not-infection-related bacterial community was discovered in uteri from humans and other mammals, and its composition is related to reproductive success. The dysbiosis of endometrial microbiota is associated with benign and malign uterine diseases. Hence, this review addressed the current knowledge about uterine microbiota alterations and their association with common endometrial diseases, including endometrial polyposis, endometriosis, uterine myomatosis, endometrial hyperplasia, and endometrial cancer. There is a specific bacterial community in the endometrium In most analyzed uterine diseases. However, the constant finding consists in a reduced abundance of Firmicutes and Lactobacillus, while there is an increased abundance of Proteobacteria (such as E. coli and Enterococcus), Bacteroidetes (Prevotella, for example), and Actinobacteria (as Gardnerella), in contrast to healthy endometrium. Besides, we discussed the future usefulness of the endometrial microbiota components as biomarkers to diagnose uterine diseases and their probable clinical outcomes. In addition, we analyzed their potential use as probiotics since they could provide an alternative or complement to existing therapies.

Placental Microarray Profiling Reveals Common mRNA and lncRNA Expression Patterns in Preeclampsia and Intrauterine Growth Restriction

Preeclampsia (PE) and Intrauterine Growth Restriction (IUGR) are major contributors to perinatal morbidity and mortality. These pregnancy disorders are associated with placental dysfunction and share similar pathophysiological features. The aim of this study was to compare the placental gene expression profiles including mRNA and lncRNAs from pregnant women from four study groups: PE, IUGR, PE-IUGR, and normal pregnancy (NP). Gene expression microarray analysis was performed on placental tissue obtained at delivery and results were validated using RTq-PCR. Differential gene expression analysis revealed that the largest transcript variation was observed in the IUGR samples compared to NP (n = 461; 314 mRNAs: 252 up-regulated and 62 down-regulated; 133 lncRNAs: 36 up-regulated and 98 down-regulated). We also detected a group of differentially expressed transcripts shared between the PE and IUGR samples compared to NP (n = 39), including 9 lncRNAs with a high correlation degree (p < 0.05). Functional enrichment of these shared transcripts showed that cytokine signaling pathways, protein modification, and regulation of JAK-STAT cascade are over-represented in both placental ischemic diseases. These findings contribute to the molecular characterization of placental ischemia showing common epigenetic regulation implicated in the pathophysiology of PE and IUGR.

The sFlt-1/PlGF ratio as a triage tool to identify superimposed preeclampsia in women with chronic hypertension in emergency rooms

OBJECTIVES

Assess the usefulness of the sFlt-1/PlGF ratio for the differential diagnosis of uncontrolled chronic hypertension vs. superimposed preeclampsia.

STUDY DESIGN

We performed a cross-sectional study from 2015 to 2017 and 42 women with initial diagnosis of superimposed preeclampsia were enrolled in the emergency room. After a 12 week follow up patients were grouped as superimposed preeclampsia (Group A) and uncontrolled chronic hypertension (Group B) according to the American College of Obstetricians and Gynecologist criteria. A group of 33 healthy women paired by gestational age were included as controls (Group C). Maternal serum levels of sFlt-1 and PlGF were measured at enrollment, and the ratios of the groups were compared.

MAIN OUTCOME MEASURES

Superimposed preeclampsia vs. uncontrolled chronic hypertension.

RESULTS

After follow-up, group distribution was 30 women in Group A, 12 women in Group B, and 25 women in Group C. The sFlt-1/PlGF ratio was higher in women with superimposed preeclampsia than in women with uncontrolled chronic hypertension (215.5 vs. 9.65, p < 0.001). The control group displayed lower ratio values (3.66, p < 0.001). The sFlt-1 concentration was higher in Group A than in Group B (7564 vs. 1281 pg/mL, p < 0.001) and the PlGF level was lower in Group A (34.39 vs. 169 pg/mL, p < 0.001).

CONCLUSIONS

The sFlt-1/PlGF ratio exhibits good performance for the differential diagnosis of superimposed preeclampsia vs. uncontrolled chronic hypertension.

New Insights into the Role of Matrix Metalloproteinases in Preeclampsia

Preeclampsia is a severe pregnancy complication globally, characterized by poor placentation triggering vascular dysfunction. Matrix metalloproteinases (MMPs) exhibit proteolytic activity implicated in the efficiency of trophoblast invasion to the uterine wall, and a dysregulation of these enzymes has been linked to preeclampsia. A decrease in MMP-2 and MMP-9 interferes with the normal remodeling of spiral arteries at early pregnancy stages, leading to the initial pathophysiological changes observed in preeclampsia. Later in pregnancy, an elevation in MMP-2 and MMP-9 induces abnormal release of vasoactive factors conditioning hypertension. Although these two enzymes lead the scene, other MMPs like MMP-1 and MMP-14 seem to have a role in this pathology. This review gathers published recent evidence about the implications of different MMPs in preeclampsia, and the potential use of these enzymes as emergent biomarkers and biological therapeutic targets, focusing on studies involving human subjects.

The paternal polymorphism rs5370 in the EDN1 gene decreases the risk of preeclampsia

OBJECTIVE

To evaluate whether the maternal, paternal or the combined maternal/paternal contribution of SNP rs5370 of the EDN1 gene is associated with preeclampsia and drove its expression in placenta.

STUDY DESIGN

This case-control study included 61 preeclamptic patients and their partners and 49 healthy pregnant women and their partners. The population was sub-divided into three groups: women-only, men-only and combined (women/men). The analysis included genotyping of rs5370 in mothers and fathers and evaluating the expression profile of the EDN1 gene in placenta. Comparisons of categorical variables were performed using chi-square and/or Fisher's exact tests. The intergroup comparisons were analysed with the Mann-Whitney U test. The association between the polymorphism and the disease was evaluated through multivariate regression analysis. Spearman's correlation was performed to test the relationship between pre-gestational history and clinical features of the affected patients with EDN1 gene expression.

RESULTS

The analysis of paternal risk factors associated with preeclampsia revealed no differences between groups. A negative association between SNP rs5370 and preeclampsia was found in men group (OR 0.42; CI 95% 0.18-0.94, p=0.034) but not in women or combined groups. The adjustment for paternal protective factors increased the observed negative association, and the opposite was observed in the presence of paternal risk factors. The expression of the EDN1 gene in the placenta was significantly higher in the group of cases and was not associated with the rs5370 polymorphism.

CONCLUSION

The paternal rs5370 polymorphism decreases the risk for preeclampsia and is not associated with placental expression of the EDN1 gene.