miR-146a-5p improves the decidual cytokine microenvironment by regulating the toll-like receptor signaling pathway in unexplained spontaneous abortion

Exosomal miR-146a-5p derived from bone marrow mesenchymal stromal cells regulate Th1/Th2 balance and alleviates immune thrombocytopenia in pregnancy

Immune thrombocytopenia (ITP) is a common hematological disorder. Our previous study has found that exosomal miR-146a-5p derived from bone marrow mesenchymal stromal cells (BMSCs) regulate Th17/Treg balance to alleviate ITP. This work further investigated the role of miR-146a-5p in ITP with pregnancy. Compared with healthy pregnant volunteers, the levels of Th1 cells and IFN-γ were increased, the levels of Th2 cells and IL-4 were decreased in peripheral blood of ITP patients with pregnancy. Then, human BMSCs-exosomes repressed the ratio of Th1/Th2 cells in CD4+ T cells, while BMSCs-exosomes with miR-146a-5p inhibitor increased Th1/Th2 cell ratio. Moreover, an ITP mouse model with pregnancy was constructed by administering anti-CD41 antibody in pregnant mice to verify the role of BMSCs-Exo in vivo. BMSCs-Exo elevated the number of platelet and megakaryocyte, improved the function of gastric, spleen and thymus tissues in ITP mice with pregnancy, which attributed to delivery miR-146a-5p. Furthermore, miR-146a-5p interacted with CARD10, and then repressed CARD10/NF-κB signaling pathway. BMSCs-exosomes promoted proliferation and inhibited apoptosis of Dami cells. In conclusion, BMSCs-exosomal miR-146a-5p reduced Th1/Th2 cell ratio to elevate proliferation and inhibit apoptosis of Dami cells, thereby alleviating ITP with pregnancy development. Therefore, miR-146a-5p may be a target for ITP with pregnancy treatment.

MicroRNA mediated regulation of oxidative stress and cytokines in Chlamydia trachomatis-infected recurrent spontaneous abortion: A case-control study

PROBLEM

Increased oxidative stress (OS) and inflammatory responses are major underlying factors behind Chlamydia trachomatis-associated recurrent spontaneous abortion (RSA). miRNAs are known to regulate inflammation and OS and their dysregulation has been associated with compromised pregnancies. Therefore, aim of this study was to investigate the expression/correlation of OS biomarkers, cytokines and miRNAs in C. trachomatis-associated RSA.

METHOD OF STUDY

Urine and non-heparinized blood samples were collected from RSA patients with history of >3 consecutive abortions (cases) and non-pregnant women with history of >2 successful deliveries (controls) attending Department of Obstetrics and Gynaecology, Safdarjung hospital, New Delhi. C. trachomatis detection was done in urine by PCR. miRNA expression was studied by microarray analysis and validated by real time-PCR. Evaluation of cytokines and antioxidant genes expression were done by real-time PCR. Level of OS biomarkers 8-hydroxy guanosine (8-OHdG) and 8-isporostane (8-IP) were measured by ELISA.

RESULTS

Fifty circulating miRNAs were differentially expressed in infected patients compared with controls. Of these, four were overexpressed and 46 downregulated. Thirteen differentially expressed circulating miRNAs were selected to validate microarray results. miRs-8069, -3663-3p showed maximum upregulation/downregulation in infected versus control group. Expression of cytokines (IL-8, TNF-α, IFN-γ), antioxidant genes SOD2 and OS biomarkers (8-OHdG,8-IP) were increased while SOD1 was decreased in infected patients. miR-8069 showed significant positive correlation with cytokines, SOD2, 8-OHdG and 8-IP. miR-3663-3p showed significant positive correlation with SOD1.

CONCLUSIONS

Overall results indicate circulating miRNAs are involved in pathogenesis of C. trachomatis-associated RSA and are potential modulators of cytokine signalling and OS in infected RSA.

Emerging role of toll-like receptors signaling and its regulators in preterm birth: a narrative review

INTRODUCTION

Despite intensive research, preterm birth (PTB) rates have not decreased significantly in recent years due to a lack of understanding of the underlying causes and insufficient treatment options for PTB. We are committed to finding promising biomarkers for the treatment of PTB.

METHODS

An extensive search of the literature was conducted with MEDLINE/PubMed, and in total, 151 studies were included and summarized in the present review.

RESULTS

Substantial evidence supports that the infection and/or inflammatory cascade associated with infection is an early event in PTB. Toll-like receptor (TLR) is a prominent pattern recognition receptor (PRR) found on both immune and non-immune cells, including fetal membrane cells. The activation of TLR downstream molecules, followed by TLR binding to its ligand, is critical for infection and inflammation, leading to the involvement of the TLR signaling pathway in PTB. TLR ligands are derived from microbial components and molecules released by damaged and dead cells. Particularly, TLR4 is an essential TLR because of its ability to recognize lipopolysaccharide (LPS). In this comprehensive overview, we discuss the role of TLR signaling in PTB, focus on numerous host-derived genetic and epigenetic regulators of the TLR signaling pathway, and cover ongoing research and prospective therapeutic options for treating PTB by inhibiting TLR signaling.

CONCLUSION

This is a critical topic because TLR-related molecules and mechanisms may enable obstetricians to better understand the physiological changes in PTB and develop new treatment and prevention strategies.

The role of miRNA molecules in the miscarriage process

The etiology and pathogenesis of miscarriage, which is the most common pregnancy complication, have not been fully elucidated. There is a constant search for new screening biomarkers that would allow for the early diagnosis of disorders associated with pregnancy pathology. The profiling of microRNA expression is a promising research area, which can help establish the predictive factors for pregnancy diseases. Molecules of microRNAs are involved in several processes crucial for the development and functioning of the body. These processes include cell division and differentiation, programmed cell death, blood vessel formation or tumorigenesis, and the response to oxidative stress. The microRNAs affect the number of individual proteins in the body due to their ability to regulate gene expression at the post-transcriptional level, ensuring the normal course of many cellular processes. Based on the scientific facts available, this paper presents a compendium on the role of microRNA molecules in the miscarriage process. The expression of potential microRNA molecules as early minimally invasive diagnostic biomarkers may be evaluated as early as the first weeks of pregnancy and may constitute a monitoring factor in the individual clinical care of women in early pregnancy, especially after the first miscarriage. To summarize, the described scientific data set a new direction of research in the development of preventive care and prognostic monitoring of the course of pregnancy.

Uterine extracellular vesicles as multi-signal messengers during maternal recognition of pregnancy in the mare

In contrast to other domestic mammals, the embryo-derived signal(s) leading to maternal recognition of pregnancy (MRP) are still unknow in the mare. We hypothesize that these embryonic signals could be packed into uterine extracellular vesicles (uEVs), acting as multi-signal messengers between the conceptus and the maternal tract, and contributing to MRP. To unveil these signals, the RNA and protein cargos of uEVs isolated from uterine lavages collected from pregnant mares (P; day 10, 11, 12 and 13 after ovulation) and cyclic control mares (C; day 10 and 13 after ovulation) were analyzed. Our results showed a fine-tuned regulation of the uEV cargo (RNAs and proteins), by the day of pregnancy, the estrous cycle, and even the size of the embryo. A particular RNA pattern was identified with specific increase on P12 related to immune system and hormonal response. Besides, a set of proteins as well as RNAs was highly enriched in EVs on P12 and P13. Differential abundance of miRNAs was also identified in P13-derived uEVs. Their target genes were linked to down- or upregulated genes in the embryo and the endometrium, exposing their potential origin. Our study identified for first time specific molecules packed in uEVs, which were previously associated to MRP in the mare, and thus bringing added value to the current knowledge. Further integrative and functional analyses will help to confirm the role of these molecules in uEVs during MRP in the mare.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

Mentha pulegium L. (Pennyroyal, Lamiaceae) Extracts Impose Abortion or Fetal-Mediated Toxicity in Pregnant Rats; Evidenced by the Modulation of Pregnancy Hormones, MiR-520, MiR-146a, TIMP-1 and MMP-9 Protein Expressions, Inflammatory State, Certain Related Signaling Pathways, and Metabolite Profiling via UPLC-ESI-TOF-MS

Pregnant women usually turn to natural products to relieve pregnancy-related ailments which might pose health risks. Mentha pulegium L. (MP, Lamiaceae) is a common insect repellent, and the present work validates its abortifacient capacity, targeting morphological anomalies, biological, and behavioral consequences, compared to misoprostol. The study also includes untargeted metabolite profiling of MP extract and fractions thereof viz. methylene chloride (MecH), ethyl acetate (EtOAc), butanol (But), and the remaining liquor (Rem. Aq.) by UPLC-ESI-MS-TOF, to unravel the constituents provoking abortion. Administration of MP extract/fractions, for three days starting from day 15th of gestation, affected fetal development by disrupting the uterine and placental tissues, or even caused pregnancy termination. These effects also entailed biochemical changes where they decreased progesterone and increased estradiol serum levels, modulated placental gene expressions of both MiR-(146a and 520), decreased uterine MMP-9, and up-regulated TIMP-1 protein expression, and empathized inflammatory responses (TNF-α, IL-1β). In addition, these alterations affected the brain's GFAP, BDNF, and 5-HT content and some of the behavioral parameters escorted by the open field test. All these incidences were also perceived in the misoprostol-treated group. A total of 128 metabolites were identified in the alcoholic extract of MP, including hydroxycinnamates, flavonoid conjugates, quinones, iridoids, and terpenes. MP extract was successful in terminating the pregnancy with minimal behavioral abnormalities and low toxicity margins.

The Role of Non-Coding RNAs in the Human Placenta

Non-coding RNAs (ncRNAs) play a central and regulatory role in almost all cells, organs, and species, which has been broadly recognized since the human ENCODE project and several other genome projects. Nevertheless, a small fraction of ncRNAs have been identified, and in the placenta they have been investigated very marginally. To date, most examples of ncRNAs which have been identified to be specific for fetal tissues, including placenta, are members of the group of microRNAs (miRNAs). Due to their quantity, it can be expected that the fairly larger group of other ncRNAs exerts far stronger effects than miRNAs. The syncytiotrophoblast of fetal origin forms the interface between fetus and mother, and releases permanently extracellular vesicles (EVs) into the maternal circulation which contain fetal proteins and RNA, including ncRNA, for communication with neighboring and distant maternal cells. Disorders of ncRNA in placental tissue, especially in trophoblast cells, and in EVs seem to be involved in pregnancy disorders, potentially as a cause or consequence. This review summarizes the current knowledge on placental ncRNA, their transport in EVs, and their involvement and pregnancy pathologies, as well as their potential for novel diagnostic tools.

Association of Polymorphisms in miR146a, an Inflammation-Associated MicroRNA, with the Risk of Idiopathic Recurrent Spontaneous Miscarriage: A Case-Control Study

It has been established that microRNAs (miRNAs) are involved in the regulation of immune responses and serve as biomarkers of inflammatory diseases as well as recurrent spontaneous miscarriage (RSM). Herein, we aimed to study the relationship between three functional miR146a gene polymorphisms with idiopathic RSM (IRSM) susceptibility. We recruited 161 patients with IRSM and 177 healthy women with at least one live birth and without a history of abortion. Genotyping was performed using RFLP-PCR and ARMS-PCR methods. We found that the rs6864584 T/C decreased the risk of IRSM under dominant TT+TC vs. CC (OR = 0.029) and allelic C vs. T (OR = 0.028) contrast models. Regarding rs2961920 A/C and rs57095329 A/G polymorphisms, the enhanced risk of IRSM was observed under different genetic contrasted models, including the codominant CC vs. AA (OR = 2.81 for rs2961920) and codominant GG vs. AA (OR = 2.36 for rs57095329). After applying a Bonferroni correction, haplotype analysis revealed a 51% decreased risk of IRSM regarding the ACA genotype combination. This is the first study reporting that miR146a rs57095329 A/G, rs2961920A/C, and rs6864584 T/C polymorphisms are associated with the risk of IRSM in a southern Iranian population. Performing replicated case-control studies on other ethnicities is warranted to outline the precise effects of the studied variants on the risk of gestational trophoblastic disorders.