Stereological study of the placental structure in abortion-prone mice model (CBA/J×DBA/2J)

Effects of autoimmune abnormalities on fertility and placental morphology in mice

Autoimmune diseases (AIDs) alter the placental immune environment leading to fetal loss. This study investigated the effects of AIDs on pregnancy and the placenta in AID-prone MRL/MpJ-Faslpr/lpr mice and wild-type MRL/MpJ, which were mated with male MRL/MpJ and MRL/MpJ-Faslpr/lpr at five months and defined as moLpr and moMpJ, respectively. AID indices (spleen weight and serum autoantibody levels) and fertility status (number and size of fetuses, morphology, and comprehensive gene expression of placentas) were evaluated on gestational day 15.5. Both strains showed equivalent fertility, but moLpr showed lighter placentas and fetuses than moMpJ, and decreased fertility with AID severity. moLpr placentas had a higher number of T cells, higher expression of genes associated with T helper 2 and T follicular helper functions, and altered expression of genes (Krt15, Slc7a3, Sprr2a3) that significantly regulate pregnancy or immunity. The gene expression of T cell migration-associated chemokines (Ccl5, Cxcl9) was significantly increased in moLpr placentas, and CCL5 and CXCL9 were detected in moLpr placentas, particularly in T cells and placenta-component cells, respectively. Thus, AID altered placental morphofunction and fertility in mice; however, fertility was maintained at the examined time points. This study enhances our understanding of placental alterations and gestational risk due to AIDs.

Regulatory T cell adoptive transfer alters uterine immune populations, increasing a novel MHC-IIlow macrophage associated with healthy pregnancy

Intrauterine fetal demise (IUFD) - fetal loss after 20 weeks - affects 6 pregnancies per 1,000 live births in the United States, and the majority are of unknown etiology. Maternal systemic regulatory T cell (Treg) deficits have been implicated in fetal loss, but whether mucosal immune cells at the maternal-fetal interface contribute to fetal loss is under-explored. We hypothesized that the immune cell composition and function of the uterine mucosa would contribute to the pathogenesis of IUFD. To investigate local immune mechanisms of IUFD, we used the CBA mouse strain, which naturally has mid-late gestation fetal loss. We performed a Treg adoptive transfer and interrogated both pregnancy outcomes and the impact of systemic maternal Tregs on mucosal immune populations at the maternal-fetal interface. Treg transfer prevented fetal loss and increased an MHC-IIlow population of uterine macrophages. Single-cell RNA-sequencing was utilized to precisely evaluate the impact of systemic Tregs on uterine myeloid populations. A population of C1q+, Trem2+, MHC-IIlow uterine macrophages were increased in Treg-recipient mice. The transcriptional signature of this novel uterine macrophage subtype is enriched in multiple studies of human healthy decidual macrophages, suggesting a conserved role for these macrophages in preventing fetal loss.

The Effects of Treatment with Icariin on Immune Tolerance in the Recurrent Spontaneous Abortion Mice

Recurrent spontaneous abortion (RSA) is the most common pregnancy-related complication, affecting 1-5% of pregnancies. Currently, immune imbalance at the maternal-fetal interface is one of the main causes of recurrent abortion. Icariin (ICA) can exert immunomodulatory effects in a variety of autoimmune diseases. Nevertheless, it has not been reported for use in recurrent abortion. In this study, to clarify the effects and mechanisms of ICA for recurrent abortion, female mice CBA/J were randomly divided into Normal group, RSA group and RSA + ICA group. From 0.5 days of pregnancy to 12.5 days, the RSA + ICA group was subjected to orally ICA (50 mg/Kg) daily, and the Normal group and the RSA group were given with an equal volume of distilled water. The results showed the amount of reabsorbed embryo in the RSA group was significantly higher than that in the normal-pregnancy group. However, ICA treatment showed a rescue effect on spontaneous abortion in RSA mice. ICA was able to increase the ratio of the labyrinth to total placental area in abortion-prone model. Further investigation showed that ICA treatment can expand the regulatory T cell (Treg) population in mice prone to abortion, significantly decrease the populations of Th1 cells, and reduce the expression of pro-inflammatory factors. Additionally, ICA treatment was able to decrease the expression of mechanical target of rapamycin (mTOR) in the placenta. ICA may increase Treg cell expansion and reducing pro-inflammatory factors expression via the mTOR pathway, then reducing placental inflammation and improving pregnancy outcomes in abortion-prone mice.

A high-fat diet changes placental morphology but does not change biochemical parameters, placental oxidative stress or cytokine levels

INTRODUCTION

The placenta is an organ that forms the bridge between mother and fetus during pregnancy. Changes in the intrauterine environment directly impact the fetus' health, with maternal nutrition determining its development. This study analyzed the effects of different diets and probiotic supplementation during pregnancy on the biochemical parameters of maternal serum and placental morphology, oxidative stress, and cytokine levels in mice.

METHODS

Female mice were fed standard (CONT), restrictive (RD), or high-fat (HFD) diets before and during pregnancy. During pregnancy, the CONT and HFD groups were divided into two groups that received the Lactobacillus rhamnosus LB1.5 three times per week (CONT + PROB and HFD + PROB). The RD, CONT, or HFD groups received vehicle control. Maternal serum biochemical parameters (glucose, cholesterol, and triglycerides) were evaluated. The morphology, redox profile (thiobarbituric acid reactive substances, sulfhydryls, catalase, and superoxide dismutase enzyme activity), and inflammatory cytokines (interleukins 1α, 1β, IL-6, and tumor necrosis factor-alpha) were evaluated in the placenta.

RESULTS

The serum biochemical parameters presented no differences between the groups. Regarding placental morphology, the HFD group showed an increased thickness of the labyrinth zone compared to the CONT + PROB group. However, no significant difference was found in the analysis of the placental redox profile and cytokine levels.

DISCUSSION

RD and HFD, for 16 weeks before and during pregnancy, as well as probiotic supplementation during pregnancy, caused no change in serum biochemical parameters nor the gestational viability rate, placental redox state, and cytokine levels. However, HFD increased the thickness of the placental labyrinth zone.

Inhibition of HMGB1 Ameliorates the Maternal-Fetal Interface Destruction in Unexplained Recurrent Spontaneous Abortion by Suppressing Pyroptosis Activation

Recurrent spontaneous abortion (RSA) is a common complication of pregnancy that affects the physical and mental health of pregnant women, and approximately 50% of the mechanisms are unclear. Our previous studies have found that high mobility group box 1 (HMGB1) molecules are highly expressed at the maternal-fetal interface of unexplained recurrent spontaneous abortion (URSA) patients. The purpose of this study was to further detect the expression of HMGB1 and pyroptosis in decidual tissue of URSA patients, and explore the potential mechanism of the protective role of HMGB1 in URSA patients and mouse model. The decidua tissues of 75 URSA patients and 75 women who actively terminated pregnancy were collected, and URSA mouse models were established and treated with HMGB1 inhibitor-aspirin. The expression of HMGB1, and their receptors (RAGE, TLR2, TLR4), pyroptosis-associated proteins (NLRP-3, caspase-1, GSDMD) and NF-κB was examined at the maternal-fetal interface of human and mouse. Our study found that HMGB1, NLRP-3, Caspase-1, GSDMD, RAGE, TLR2 and TLR4 were highly expressed and NF-κB signaling pathway were activated in the decidua tissue of URSA group. Moreover, immune cell disorder and co-localization of HMGB1 and macrophages were found at the maternal-fetal interface of URSA mice. However, HMGB1, TLR2, TLR4, NF-κB, and pyroptosis-associated proteins can be down-regulated by administering low-dose aspirin. These data may indicate that highly expressed HMGB1 was actively secreted by macrophages and then activated pyroptosis through the TLR2/TLR4-NF-κB pathway to cause aseptic inflammation, leading to the occurrence and development of URSA. Moreover, low-dose aspirin can reduce HMGB1 protein levels of serum and decidual in URSA.

Pristimerin Suppresses Trophoblast Cell Epithelial-Mesenchymal Transition via miR-542-5p/EGFR Axis

Background

Ectopic pregnancy (EP) is an ectopic embryo implantation occurred outside the uterine cavity. Nowadays, more attention have garnered in fast and effective treatment with less side effects. Pristimerin is known as the clinical application for anti-cancer, and the effect on EP therapy is still unclear.

Materials and Methods

Trophoblast cell line HTR-8/SVneo was used; then, we performed cell counting kit-8 assay, wound healing assay, flow cytometry and real-time polymerase chain reaction analysis (RT-PCR) to detect the cell viability, migration ability, apoptosis and epithelial–mesenchymal transition (EMT) under pristimerin treatment. In addition, public bioinformatic database was used to discover the connection between molecular and genes. Finally, we used miRNA transfection and RT-PCR techniques to determine the underlying molecular mechanism.

Results

We revealed that pristimerin inhibited trophoblast cells proliferation, migration and EMT, while induced trophoblast cell apoptosis. Furthermore, expression of miR-542-5p, AGO2 and EGFR was suppressed in HTR-8/SVneo cells post pristimerin treatment, and miR-542-5p silence showed the same effect. Combing pristimerin treatment and miR-542-5p silence showed a synergistic action.

Conclusion

Pristimerin could be an effective treatment to block embryo implantation by miR-542-5p and EGFR down-regulation.