Differential expression of circulating miRNAs in maternal plasma in pregnancies with fetal macrosomia

Association of placental PPARα/γ and miR-27b expression with macrosomia in healthy pregnancy

BACKGROUND

Peroxisomal proliferator-activated receptors (PPARs) and microRNAs (miRNAs) play important roles in the development of fetuses, whereas expression changes of PPARs and three miRNAs (miR-17, miR-27b and miR-34a) and whether these miRNAs regulate PPARs in non-GDM macrosomia placenta is unclear.

METHODS

A case-control study was performed to collect information and placental tissues on mothers and newborns of non-GDM macrosomia and normal-birth-weight infants. In vitro HTR8-SVneo cellular model was used to detect the effects of miRNAs on PPARs expression. Quantitative real-time PCR (qRT-PCR) and western blot was applied to examine the expression levels of PPARs, miR-17, miR-27b, and miR-34a in placental tissues and cells.

RESULTS

The PPARα/γ mRNA and protein levels were significantly up-regulated and miR-27b was down-regulated in the placenta of macrosomia group compared with in the control group, while no difference was observed in PPARβ, miR-17, and miR-34a. After adjusting for confounding factors, low miR-27b and high PPARα/γ mRNA expression still increased the risk of macrosomia. The PPARα/γ protein levels presented a corresponding decrease or increase when cells were transfected with miR-27b mimic or inhibitor.

CONCLUSIONS

Placental PPARα/γ and miR-27b expression were associated with non-GDM macrosomia and miR-27b probably promotes the occurrence of non-GDM macrosomia by regulating PPARα/γ protein.

IMPACT

Low miR-27b and high PPARα/γ mRNA expression in the placenta were associated with higher risk of macrosomia. In vitro HTR8-SVneo cell experiment supported that miR-27b could negatively regulate the expression of PPARα and PPARγ protein. MiR-27b was probably involved in non-GDM macrosomia through negative regulation of PPARα/γ protein.

Effective Macrosomia Prediction Using Random Forest Algorithm

(1) Background: Macrosomia is prevalent in China and worldwide. The current method of predicting macrosomia is ultrasonography. We aimed to develop new predictive models for recognizing macrosomia using a random forest model to improve the sensitivity and specificity of macrosomia prediction; (2) Methods: Based on the Shandong Multi-Center Healthcare Big Data Platform, we collected the prenatal examination and delivery data from June 2017 to May 2018 in Jinan, including the macrosomia and normal-weight newborns. We constructed a random forest model and a logistic regression model for predicting macrosomia. We compared the validity and predictive value of these two methods and the traditional method; (3) Results: 405 macrosomia cases and 3855 normal-weight newborns fit the selection criteria and 405 pairs of macrosomia and control cases were brought into the random forest model and logistic regression model. On the basis of the average decrease of the Gini coefficient, the order of influencing factors was: interspinal diameter, transverse outlet, intercristal diameter, sacral external diameter, pre-pregnancy body mass index, age, the number of pregnancies, and the parity. The sensitivity, specificity, and area under curve were 91.7%, 91.7%, and 95.3% for the random forest model, and 56.2%, 82.6%, and 72.0% for logistic regression model, respectively; the sensitivity and specificity were 29.6% and 97.5% for the ultrasound; (4) Conclusions: A random forest model based on the maternal information can be used to predict macrosomia accurately during pregnancy, which provides a scientific basis for developing rapid screening and diagnosis tools for macrosomia.

Preeclamptic Women Have Disrupted Placental microRNA Expression at the Time of Preeclampsia Diagnosis: Meta-Analysis

Introduction: Preeclampsia (PE) is a pregnancy-associated, multi-organ, life-threatening disease that appears after the 20th week of gestation. The aim of this study was to perform a systematic review and meta-analysis to determine whether women with PE have disrupted miRNA expression compared to women who do not have PE. Methods: We conducted a systematic review and meta-analysis of studies that reported miRNAs expression levels in placenta or peripheral blood of pregnant women with vs. without PE. Studies published before October 29, 2021 were identified through PubMed, EMBASE and Web of Science. Two reviewers used predefined forms and protocols to evaluate independently the eligibility of studies based on titles and abstracts and to perform full-text screening, data abstraction and quality assessment. Standardized mean difference (SMD) was used as a measure of effect size. Results: 229 publications were included in the systematic review and 53 in the meta-analysis. The expression levels in placenta were significantly higher in women with PE compared to women without PE for miRNA-16 (SMD = 1.51,95%CI = 0.55-2.46), miRNA-20b (SMD = 0.89, 95%CI = 0.33-1.45), miRNA-23a (SMD = 2.02, 95%CI = 1.25-2.78), miRNA-29b (SMD = 1.37, 95%CI = 0.36-2.37), miRNA-155 (SMD = 2.99, 95%CI = 0.83-5.14) and miRNA-210 (SMD = 1.63, 95%CI = 0.69-2.58), and significantly lower for miRNA-376c (SMD = -4.86, 95%CI = -9.51 to -0.20). An increased level of miRNK-155 expression was found in peripheral blood of women with PE (SMD = 2.06, 95%CI = 0.35-3.76), while the expression level of miRNA-16 was significantly lower in peripheral blood of PE women (SMD = -0.47, 95%CI = -0.91 to -0.03). The functional roles of the presented miRNAs include control of trophoblast proliferation, migration, invasion, apoptosis, differentiation, cellular metabolism and angiogenesis. Conclusion: miRNAs play an important role in the pathophysiology of PE. The identification of differentially expressed miRNAs in maternal blood creates an opportunity to define an easily accessible biomarker of PE.

High-Throughput Sequencing of Circulating MicroRNAs in Plasma and Serum during Pregnancy Progression

Although circulating microRNAs (miRNAs) in maternal blood may play an important role in regulation of pregnancy progression and serve as non-invasive biomarkers for different gestation complications, little is known about their profile in blood during normally developing pregnancy. In this study we evaluated the miRNA profiles in paired plasma and serum samples from pregnant women without health or gestational abnormalities at three time points using high-throughput sequencing technology. Sequencing revealed that the percentage of miRNA reads in plasma and serum decreased by a third compared to first and second trimesters. We found two miRNAs in plasma (hsa-miR-7853-5p and hsa-miR-200c-3p) and 10 miRNAs in serum (hsa-miR-203a-5p, hsa-miR-495-3p, hsa-miR-4435, hsa-miR-340-5p, hsa-miR-4417, hsa-miR-1266-5p, hsa-miR-4494, hsa-miR-134-3p, hsa-miR-5008-5p, and hsa-miR-6756-5p), that exhibit level changes during pregnancy (p-value adjusted < 0.05). In addition, we observed differences for 36 miRNAs between plasma and serum (p-value adjusted < 0.05), which should be taken into consideration when comparing the results between studies performed using different biosample types. The results were verified by analysis of three miRNAs using qRT-PCR (p < 0.05). The present study confirms that the circulating miRNA profile in blood changes during gestation. Our results set the basis for further investigation of molecular mechanisms, involved in regulation of pregnancy, and the search for biomarkers of gestation abnormalities.

Role of Extracellular Vesicles in Placental Inflammation and Local Immune Balance

Background

Pregnancy maintenance depends on the formation of normal placentas accompanied by trophoblast invasion and vascular remodeling. Various types of cells, such as trophoblasts, endothelial cells, immune cells, mesenchymal stem cells (MSCs), and adipocytes, mediate cell-to-cell interactions through soluble factors to maintain normal placental development. Extracellular vesicles (EVs) are diverse nanosized to microsized membrane-bound particles released from various cells. EVs contain tens to thousands of different RNA, proteins, small molecules, DNA fragments, and bioactive lipids. EV-derived microRNAs (miRNAs) and proteins regulate inflammation and trophoblast invasion in the placental microenvironment. Maternal-fetal communication through EV can regulate the key signaling pathways involved in pregnancy maintenance, from implantation to immune regulation. Therefore, EVs and the encapsulating factors play important roles in pregnancy, some of which might be potential biomarkers.

Conclusion

In this review, we have summarized published studies about the EVs in the placentation and pregnancy-related diseases. By summarizing the role of EVs and their delivering active molecules in pregnancy-related diseases, it provides novel insight into the diagnosis and treatment of diseases.

The Predictive Value of miR-16, -29a and -134 for Early Identification of Gestational Diabetes: A Nested Analysis of the DALI Cohort

Early identification of gestational diabetes mellitus (GDM) aims to reduce the risk of adverse maternal and perinatal outcomes. Currently, no circulating biomarker has proven clinically useful for accurate prediction of GDM. In this study, we tested if a panel of small non-coding circulating RNAs could improve early prediction of GDM. We performed a nested case-control study of participants from the European multicenter ‘Vitamin D and lifestyle intervention for GDM prevention (DALI)’ trial using serum samples from obese pregnant women (BMI ≥ 29 kg/m²) entailing 82 GDM cases (early- and late- GDM), and 41 age- and BMI-matched women with normal glucose tolerance (NGT) throughout pregnancy (controls). Anthropometric, clinical and biochemical characteristics were obtained at baseline (<20 weeks of gestation) and throughout gestation. Baseline serum microRNAs (miRNAs) were measured using quantitative real time PCR (qPCR). Elevated miR-16-5p, -29a-3p, and -134-5p levels were observed in women, who were NGT at baseline and later developed GDM, compared with controls who remained NGT. A combination of the three miRNAs could distinguish later GDM from NGT cases (AUC 0.717, p = 0.001, compared with fasting plasma glucose (AUC 0.687, p = 0.004)) as evaluated by area under the curves (AUCs) using Receiver Operator Characteristics (ROC) analysis. Elevated levels of individual miRNAs or a combination hereof were associated with higher odds ratios of GDM. Conclusively, circulating miRNAs early in pregnancy could serve as valuable predictive biomarkers of GDM.

Circulating microRNAs overexpressed in macrosomia: an experimental and bioinformatic approach

Low birth weight (LBW) and macrosomia have been associated with later-in-life metabolic alterations. The aim of this study was to elucidate whether the expression levels of circulating microRNAs (c-miRNAs) associated with adult metabolic diseases are also dysregulated in newborns with LBW or macrosomia. The expression levels of five microRNAs (miRNAs) associated with metabolic diseases were quantified in dried blood spots of newborns with adequate birth weight, LBW and macrosomia by stem-loop real-time polymerase chain reaction. miR-29a-5p, miR-126-3p, miR-221-3p, and miR-486-5p were significantly overexpressed in newborns with macrosomia and showed no significant change in the LBW group compared to normal weight controls. miR-320a showed no statistical difference among groups. We predicted the putative target genes and pathways of the overexpressed miRNAs with bioinformatic tools. Bioinformatic analyses of overexpressed miRNAs predicted target genes involved in carbohydrate metabolism, participate in FoxO and PI3K/Akt signaling pathways, and are associated with diabetes, obesity, and cardiovascular diseases. The overexpression of circulating miR-29a-5p, miR-126-3p, miR-221-3p, and miR-486-5p may explain the increased risk of obesity and diabetes associated with macrosomia. The use of dried blood spots from newborn screening cards to quantify miRNAs expression levels could be an early and minimally invasive predictive tool for these metabolic alterations.

MiRNAs in the Peri-Implantation Period: Contribution to Embryo-Maternal Communication in Pigs

MicroRNAs (miRNAs) constitute a large family of noncoding RNAs, approximately 22 nucleotides long, which function as guide molecules in RNA silencing. Targeting most protein-coding transcripts, miRNAs are involved in nearly all developmental and pathophysiological processes in animals. To date, the regulatory roles of miRNAs in reproduction, such as fertilization, embryo development, implantation, and placenta formation, among others, have been demonstrated in numerous mammalian species, including domestic livestock such as pigs. Over the past years, it appeared that understanding the functions of miRNAs in mammalian reproduction can substantially improve our understanding of the biological challenges of successful reproductive performance. This review describes the current knowledge on miRNAs, specifically in relation to the peri-implantation period when the majority of embryonic mortality occurs in pigs. To present a broader picture of crucial peri-implantation events, we focus on the role of miRNA-processing machinery and miRNA–mRNA infarctions during the maternal recognition of pregnancy, leading to maintenance of the corpus luteum function and further embryo implantation. Furthermore, we summarize the current knowledge on cell-to-cell communication involving extracellular vesicles at the embryo–maternal interface in pigs. Finally, we discuss the potential of circulating miRNAs to serve as indicators of ongoing embryo–maternal crosstalk.

Diabetes in Pregnancy and MicroRNAs: Promises and Limitations in Their Clinical Application

Maternal diabetes is associated with an increased risk of complications for the mother and her offspring. The latter have an increased risk of foetal macrosomia, hypoglycaemia, respiratory distress syndrome, preterm delivery, malformations and mortality but also of life-long development of obesity and diabetes. Epigenetics have been proposed as an explanation for this long-term risk, and microRNAs (miRNAs) may play a role, both in short- and long-term outcomes. Gestation is associated with increasing maternal insulin resistance, as well as β-cell expansion, to account for the increased insulin needs and studies performed in pregnant rats support a role of miRNAs in this expansion. Furthermore, several miRNAs are involved in pancreatic embryonic development. On the other hand, maternal diabetes is associated with changes in miRNA both in maternal and in foetal tissues. This review aims to summarise the existing knowledge on miRNAs in gestational and pre-gestational diabetes, both as diagnostic biomarkers and as mechanistic players, in the development of gestational diabetes itself and also of short- and long-term complications for the mother and her offspring.

Offspring of mothers with hyperglycaemia in pregnancy: The short term and long-term impact. What is new?

The continuing rise in the global prevalence of diabetes and overweight or obesity has become a major burden for global health, as the pandemic is affecting both high and low-middle income countries (LMIC). At the same time, a similar pattern has been observed for all forms of hyperglycemia in pregnancy (HIP), diabetes during pregnancy and gestational diabetes. The offspring of mothers with HIP and/or overweight-obesity is receiving increasing attention as advances in early detection and treatment of HIP did not completely prevent macrosomia and its associated short-term perinatal disorders, whilst long term consequences are observed in the mother and in offspring as it reaches adulthood. This review discusses the current developments in the consequences of HIP in the offspring, with a particular focus on its long-term health at adulthood, and on intergenerational and transgenerational effects. HIP is emerging as one of the factors that can contribute, during the window of sensitivity to environmental cues constituted by the preconception, pregnancy, and early childhood, and as an amplifying factor linked to reproduction, to the current global epidemic of diabetes and non-communicable diseases (NCDs).

Biomarkers for Macrosomia Prediction in Pregnancies Affected by Diabetes

Large birthweight, or macrosomia, is one of the commonest complications for pregnancies affected by diabetes. As macrosomia is associated with an increased risk of a number of adverse outcomes for both the mother and offspring, accurate antenatal prediction of fetal macrosomia could be beneficial in guiding appropriate models of care and interventions that may avoid or reduce these associated risks. However, current prediction strategies which include physical examination and ultrasound assessment, are imprecise. Biomarkers are proving useful in various specialties and may offer a new avenue for improved prediction of macrosomia. Prime biomarker candidates in pregnancies with diabetes include maternal glycaemic markers (glucose, 1,5-anhydroglucitol, glycosylated hemoglobin) and hormones proposed implicated in placental nutrient transfer (adiponectin and insulin-like growth factor-1). There is some support for an association of these biomarkers with birthweight and/or macrosomia, although current evidence in this emerging field is still limited. Thus, although biomarkers hold promise, further investigation is needed to elucidate the potential clinical utility of biomarkers for macrosomia prediction for pregnancies affected by diabetes.

Differential expression profiles of circulating microRNAs in newborns associated to maternal pregestational overweight and obesity

BACKGROUND

The perinatal environment has a role in the establishment of altered metabolic and inflammatory responses, and could be modulated by microRNAs regulating immune and metabolic processes.

OBJECTIVE

To analyze the expression profile of four circulating microRNAs and cytokine serum concentrations in neonates born to overweight and obese women.

METHODS

Pregnant women were included and grouped by pregestational body mass index (21 with normal weight, 10 overweight and 10 obese women). A peripheral blood sample was obtained from newborn infants and used to determine circulating miRNAs expression and cytokine serum concentrations.

RESULTS

There were significant differences in the expression of three microRNAs between newborns of pregestational obese women and newborns from pregestational normal weight women: miR-155 (p = 0.03), miR-181a (p = 0.02) and miR-221 (p = 0.04). A significant reduction in IL-1β (p = 0.005) expression was also found in newborns of overweight women; although this cytokine was also diminished in newborns of obese women, this was not statistically significant. An association between IL-1β concentrations and miR-146a and miR-221 expression was also observed.

CONCLUSIONS

Expression of miR-155, miR-181a and miR-221 differs in infants born to obese women compared with infants born to normal weight women. Changes in microRNA expression could participate in the epigenetic foetal programming of metabolic disorders in children born to obese women.

Second trimester extracellular microRNAs in maternal blood and fetal growth: An exploratory study

Healthy feto-maternal communication is critical during pregnancy and is orchestrated by the placenta. Dysfunction of the placenta leads to fetal growth complications; however, the underlying biological mechanisms have yet to be fully elucidated. Circulating extracellular microRNAs (exmiRNAs) in the blood have been implicated in cell-to-cell communication. Therefore, exmiRNAs may provide useful biological information about communication between the mother, the fetus, and the placenta during pregnancy. We used logistic regression to determine the association of exmiRNAs with abnormal fetal growth by comparing mothers of infants classified as small-for-gestational age (SGA) (n = 36) and large-for-gestational age (LGA) (n = 13) to appropriate-for-gestational age (AGA), matched by gestational age at delivery and infant sex. In addition, we used linear regression to determine associations between exmiRNAs and birth weight-for-gestational age (BWGA) z-score (n = 100), adjusting for maternal age, body mass index, and parity. We found that higher levels of miR-20b-5p, miR-942-5p, miR-324-3p, miR-223-5p, and miR-127-3p in maternal serum were associated with lower odds for having a SGA vs. AGA infant, and higher levels of miR-661, miR-212-3p, and miR-197-3p were associated with higher odds for having a LGA vs. AGA infant. We also found associations between miR-483-5p, miR-10a-5p, miR-204-5p, miR-202-3p, miR-345-5p, miR-885-5p, miR-127-3p, miR-148b-3p, miR-324-3p, miR-1290, miR-597-5p, miR-139-5p, miR-215-5p, and miR-99b-5p and BWGA z-score. We also found sex-specific associations with exmiRNAs and fetal growth. Our findings suggest that exmiRNAs circulating in maternal blood at second trimester are associated with fetal growth. Validation of our findings may lead to the development of minimally-invasive biomarkers of fetal growth during pregnancy.

The Role of miRNAs as Biomarkers for Pregnancy Outcomes: A Comprehensive Review

Several studies showed that altered expression of the miRNA-ome in maternal circulation or in placental tissue may reflect not only gestational disorders, such as preeclampsia, spontaneous abortion, preterm birth, low birth weight, or macrosomia, but also prenatal exposure to environmental pollutants. Generally, the relationships between environmental exposure, changes in miRNA expression, and gestational disorders are explored separately, producing conflicting findings. However, validation of tissue-accessible biomarkers for the monitoring of adverse pregnancy outcomes needs a systematic methodological approach that takes also into account early-life environmental exposure. To achieve this goal, exposure to xenochemicals, endogenous agents, and diet should be assessed. This study has the aim to provide a comprehensive review on the role of miRNAs as potential biomarkers for adverse pregnancy outcomes and prenatal environmental exposure.

The role, mechanism and potentially novel biomarker of microRNA-17-92 cluster in macrosomia

Macrosomia is one of the most common perinatal complications of pregnancy and has life-long health implications for the infant. microRNAs (miRNAs) have been identified to regulate placental development, yet the role of miRNAs in macrosomia remains poorly understood. Here we investigated the role of miR-17-92 cluster in macrosomia. The expression levels of five miRNAs in miR-17-92 cluster were significantly elevated in placentas of macrosomia, which may due to the up-regulation of miRNA-processing enzyme Drosha and Dicer. Cell cycle pathway was identified to be the most relevant pathways regulated by miR-17-92 cluster miRNAs. Importantly, miR-17-92 cluster increased proliferation, attenuated cell apoptosis and accelerated cells entering S phase by targeting SMAD4 and RB1 in HTR8/SVneo cells. Furthermore, we found that expression of miR-17-92 cluster in serum had a high diagnostic sensitivity and specificity for macrosomia (AUC: 80.53%; sensitivity: 82.61%; specificity: 69.57%). Our results suggested that miR-17-92 cluster contribute to macrosomia development by targeting regulators of cell cycle pathway. Our findings not only provide a novel insight into the molecular mechanisms of macrosomia, but also the clinical value of miR-17-92 cluster as a predictive biomarker for macrosomia.

Amplification-based method for microRNA detection

Over the last two decades, the study of miRNAs has attracted tremendous attention since they regulate gene expression post-transcriptionally and have been demonstrated to be dysregulated in many diseases. Detection methods with higher sensitivity, specificity and selectivity between precursors and mature microRNAs are urgently needed and widely studied. This review gave an overview of the amplification-based technologies including traditional methods, current modified methods and the cross-platforms of them combined with other techniques. Many progresses were found in the modified amplification-based microRNA detection methods, while traditional platforms could not be replaced until now. Several sample-specific normalizers had been validated, suggesting that the different normalizers should be established for different sample types and the combination of several normalizers might be more appropriate than a single universal normalizer. This systematic overview would be useful to provide comprehensive information for subsequent related studies and could reduce the un-necessary repetition in the future.