Analysis of Varying MicroRNAs as a Novel Biomarker for Early Diagnosis of Preeclampsia: A Scoping Systematic Review of the Observational Study

The Endometrial Stem/Progenitor Cells and Their Niches

Endometrial stem/progenitor cells are a type of stem cells with the ability to self-renew and differentiate into multiple cell types. They exist in the endometrium and form niches with their neighbor cells and extracellular matrix. The interaction between endometrial stem/progenitor cells and niches plays an important role in maintaining, repairing, and regenerating the endometrial structure and function. This review will discuss the characteristics and functions of endometrial stem/progenitor cells and their niches, the mechanisms of their interaction, and their roles in endometrial regeneration and diseases. Finally, the prospects for their applications will also be explored.

Prediction of severe preeclampsia and intrauterine growth restriction based on serum placental exosome miR-520a-5p levels during the first-trimester

BACKGROUND

To assess the predictive capabilities of serum exosomal levels of micro-RNA-520a-5p (miR-520a-5p) concerning the occurrence of severe preeclampsia (sPE) and fetal growth restriction (FGR) during the first trimester of pregnancy.

METHODS

During the period spanning from October 2020 to October 2021, serum samples were procured from the first trimester and subsequently preserved by freezing at -80 ℃. These samples were obtained from 105 pregnant women in a nested case-control study. This cohort consisted of individuals who later developed sPE (sPE group, n = 35) and FGR (FGR group, n = 35) during the third trimester. Additionally, 35 women with normal blood pressure were denoted as normal pregnancy group. Serum samples from the first trimester were retrieved from all groups for further analysis after thawing. Exosomes were extracted from the serum samples collected during the first trimester and examined using transmission electron microscopy, western blot, and nanoparticle tracking analysis. Additionally, the determination of their placental origin was also established during the course of the study. Exosome miR-520a-5p levels were measured using real-time quantitative polymerase chain reaction assays, primarily involving quantitative reverse transcription polymerase chain reactions. Fetal placental tissues from the 3 groups were collected shortly after birth, and miR-520a-5p expression was measured using real-time quantitative polymerase chain reaction. Serum placental exosomes and fetal placental tissues were compared for miR-520a-5p levels. Placental trophoblasts were identified as the source of serum exosomes in all 3 groups.

RESULTS

It was found that serum placental exosomes exhibited lower levels of miR-520a-5p in both the sPE and FGR groups when compared to the normal pregnancy group. This finding was consistent with observations made in postpartum placental tissues. The predictive accuracy for sPE using miR-520a-5p levels in serum placental exosomes during the first trimester was notably higher (area under the receiver operating characteristic curve = 0.806, P <.05) compared to the prediction of FGR (area under the receiver operating characteristic curve = 0.628, P <.05).

CONCLUSION

Placenta-derived exosomes can be extracted from maternal serum during the first trimester of pregnancy and miR-520a-5p detected from the exosomes. The downregulation of miR-520a-5p serves as a more predictive indicator for the subsequent development of sPE compared to predicting FGR.

Association between vitamin D receptor gene variants and neonatal sepsis: A systematic review and meta-analysis

The objective of this systematic review and meta-analysis was elucidating the association of VDR SNPs (FokI, TaqI, BsmI, BgII, and ApaI) with neonatal sepsis. Literature search was performed to retrieve records published until August 2nd, 2023 (PROSPERO registration: CRD42023451355). Meta-analysis was carried out to determine the pooled estimates for Odds Ratio (OR). A total of four studies were included with 500 neonates (250 sepsis cases and 250 healthy controls). There was an association observed between TaqI SNP with neonatal sepsis for CT vs. CC+TT (OR=1.95) and TT vs CT+CC (OR=0.40). Moreover, the pooled estimates also suggested that CC vs. CT+TT (OR= 0.37) and C vs. T (OR=0.66) of FokI SNP were significantly associated with neonatal sepsis. SNP of BgII was found to be significantly associated with neonatal sepsis, but only reported in a single study.

Exosomal small RNA profiling in first-trimester maternal blood explores early molecular pathways of preterm preeclampsia

Introduction

Preeclampsia (PE) is a severe obstetrical syndrome characterized by new-onset hypertension and proteinuria and it is often associated with fetal intrauterine growth restriction (IUGR). PE leads to long-term health complications, so early diagnosis would be crucial for timely prevention. There are multiple etiologies and subtypes of PE, and this heterogeneity has hindered accurate identification in the presymptomatic phase. Recent investigations have pointed to the potential role of small regulatory RNAs in PE, and these species, which travel in extracellular vesicles (EVs) in the circulation, have raised the possibility of non-invasive diagnostics. The aim of this study was to investigate the behavior of exosomal regulatory small RNAs in the most severe subtype of PE with IUGR.

Methods

We isolated exosomal EVs from first-trimester peripheral blood plasma samples of women who later developed preterm PE with IUGR (n=6) and gestational age-matched healthy controls (n=14). The small RNA content of EVs and their differential expression were determined by next-generation sequencing and further validated by quantitative real-time PCR. We also applied the rigorous exceRpt bioinformatics pipeline for small RNA identification, followed by target verification and Gene Ontology analysis.

Results

Overall, >2700 small RNAs were identified in all samples and, of interest, the majority belonged to the RNA interference (RNAi) pathways. Among the RNAi species, 16 differentially expressed microRNAs were up-regulated in PE, whereas up-regulated and down-regulated members were equally found among the six identified Piwi-associated RNAs. Gene ontology analysis of the predicted small RNA targets showed enrichment of genes in pathways related to immune processes involved in decidualization, placentation and embryonic development, indicating that dysregulation of the induced small RNAs is connected to the impairment of immune pathways in preeclampsia development. Finally, the subsequent validation experiments revealed that the hsa_piR_016658 piRNA is a promising biomarker candidate for preterm PE associated with IUGR.

Discussion

Our rigorously designed study in a homogeneous group of patients unraveled small RNAs in circulating maternal exosomes that act on physiological pathways dysregulated in preterm PE with IUGR. Therefore, our small RNA hits are not only suitable biomarker candidates, but the revealed biological pathways may further inform us about the complex pathology of this severe PE subtype.

Recent Advances in the Prevention and Screening of Preeclampsia

Throughout the history of medicine, preeclampsia has remained an enigmatic field of obstetrics. In 2023, despite its prevalence and impact, preeclampsia's exact cause and effective treatment remain elusive; the current options are limited to delivery. The purpose of this review is to summarize the knowledge of the possible novel prophylactic therapies and screening methods for preeclampsia, thereby providing valuable insights for healthcare professionals and researchers. Aspirin and LMWH have already been widely used; meanwhile, calcium, vitamin D, and pravastatin show promise, and endothelin receptor antagonists are being explored. Stress reduction, dietary changes, and lifestyle modifications are also being investigated. Another interesting and fast-growing area is AI- and software-based screening methods. It is also key to find novel biomarkers, which, in some cases, are not only able to predict the development of the disease, but some of them hold promise to be a potential therapeutic target. We conclude that, while a definitive cure for preeclampsia may not be eligible in the near future, it is likely that the assessment and enhancement of preventive methods will lead to the prevention of many cases. However, it is also important to highlight that more additional research is needed in the future to clarify the exact pathophysiology of preeclampsia and to thus identify potential therapeutic targets for more improved treatment methods.