AMPK regulates homeostasis of invasion and viability in trophoblasts by redirecting glucose metabolism: Implications for pre-eclampsia

MTHFD2: A metabolic checkpoint altering trophoblast invasion and migration by remodeling folate-nucleotide metabolism in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) affects female reproduction worldwide, yet its pathological mechanisms are still unclear. It has been reported that cellular metabolism reprogramming is a critical step for trophoblasts during embryo implantation. Herein, MTHFD2 was recognized as a key metabolic checkpoint attributed to RSA occurrence. This work figured out that the expression level of MTHFD2 was significantly inhibited in villus tissues from RSA patients, suggesting the potential role of MTHFD2 in RSA occurrence. Moreover, MTHFD2 knockdown impaired cellular folate-nucleotide metabolism, induced the accumulation of AICAR, and thereby impairing the EMT process to inhibit the invasion and migration of trophoblasts Besides, the AICAR accumulation further activated the downstream AMPK which deactivated the JAK/STAT/Slug pathway and ultimately deactivated the EMT process. Using a mouse model, MTHFD2 inhibition was observed to induce embryo implantation failure in vivo. Our results highlighted MTHFD2 as a metabolic checkpoint that remodeled folate-nucleotide metabolism to regulate the EMT process and ultimately altered the migration and invasion of trophoblasts in RSA occurrence. Our findings suggested that MTHFD2 was a promising therapeutic target in recurrent spontaneous abortion treatment.

Compromised Peroxisome Proliferator-Activated Receptor γ-Mediated Impaired Placental Glucose Transport Via the Phosphatidylinositol 3-Kinase/Protein Kinase B Signaling Pathway Is Associated With Fetal Growth Restriction

Fetal growth restriction (FGR) is a condition in which a fetus cannot grow to its full potential during pregnancy. It is a leading cause of perinatal mortality and morbidity. However, the underlying etiology remains elusive. Here, we report that peroxisome proliferator-activated receptor γ (PPARγ) is inactivated in the trophoblasts of the human placenta of FGR-complicated pregnancies. In the FGR placentas, p-PI3KTyr458 and p-AKTSer473 levels were also lowered. Additionally, there was a reduction in GLUT3 and GLUT4 levels in the cell membrane. Consistently, FGR patients showed decreased glucose concentrations in both the placenta and umbilical cord blood compared with that in normal pregnancy. In mouse models, deletion of Pparg in trophoblasts and reduced uterine perfusion pressure surgery successfully induced FGR and replicated these changes. Modulating PPARγ activity using rosiglitazone or GW9662 in BeWo cells, a model of syncytiotrophoblasts, resulted in the activation or inhibition of the phosphatidylinositol 3-kinase/protein kinase B signaling pathway, as well as the promotion or reduction of membrane translocation of GLUT3 and GLUT4, ultimately affecting glucose uptake in trophoblast cells. MK-2206 blocked these regulatory effects of rosiglitazone in BeWo cells. Furthermore, the administration of rosiglitazone encapsulated in placenta-targeting nanoparticles improved the growth and development of fetal mice in the reduced uterine perfusion pressure group. In summary, PPARγ in trophoblast cells orchestrates the translocation of GLUT3 and GLUT4 to the cellular membrane via the phosphatidylinositol 3-kinase/protein kinase B signaling pathway, thereby regulating cellular glucose uptake and transport. Dysfunctions in this mechanism are strongly associated with FGR. Therefore, targeted activation of PPARγ in the placenta may be a potentially efficacious intrauterine intervention for FGR.

The Placenta Regulates Intrauterine Fetal Growth via Exosomal PPARγ

Abnormal adipogenesis is a major contributor to fetal growth restriction (FGR) and its associated complications. However, the underlying etiology remains unclear. Here, it is reported that the placentas of women with pregnancies complicated with FGR exhibit peroxisome proliferator-activated receptor γ (PPARγ) inactivation. In mice, trophoblast-specific ablation of murine PPARγ reproduces the phenotype of human fetuses with FGR and defective adipogenesis. Coculture of trophoblasts with preadipocytes significantly improves preadipocyte commitment and differentiation and increases the transcription of a series of adipogenic genes via intercellular transfer of exosomal PPARγ proteins. Moreover, nanoparticle-mediated placenta-specific delivery of rosiglitazone (RGZ) significantly rescues adipogenesis defects in an FGR-induced mouse model. In summary, the placenta is a major reservoir of PPARγ. An insufficient supply of placental PPARγ to fetal preadipocytes via exosomes during late gestation is a major mechanism underlying FGR. Preclinically, placenta-targeted RGZ administration can be a promising interventional therapy for FGR and/or defective intrauterine fat development.

Metabolic Profiles of Pregnancy with Polycystic Ovary Syndrome: Insights into Maternal-Fetal Metabolic Communication

CONTEXT

PCOS pregnancies are linked to metabolic disorders affecting maternal and fetal outcomes, with maternal metabolites differing from those in normal pregnancies.

OBJECTIVE

To investigate the metabolic communication at the maternal-fetal interface in PCOS pregnancies.

DESIGN

Placenta and umbilical cord serum were analyzed using gas chromatography-mass spectrometry. In-depth analysis was performed with clinical characteristics.

SETTING

Placenta and umbilical cord serum were analyzed using gas chromatography-mass spectrometry, alongside clinical characteristics.

PARTICIPANTS

45 uncomplicated PCOS pregnancies and 50 normal pregnancies.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The metabolic characteristics at the maternal-fetal interface in PCOS pregnancies and the underlying mechanisms.

RESULTS

A total of 79 metabolites in the placenta and 25 in umbilical cord serum showed significant differences between polycystic ovary syndrome (PCOS) and normal pregnancies. The 10 most significant placental metabolites were identified through receiver operating characteristic (ROC) analysis, 9 of which correlated significantly with maternal serum testosterone levels. Lasso regression analysis identified 4 key placental metabolite combinations: gamma-aminobutyric acid, proline, glycine, and isoleucine, achieving an area under the curve (AUC) of 93.24%. In umbilical cord serum, 6 metabolites differed significantly between PCOS and normal pregnancies, with the highest AUC reaching 76.07%, and 5 of these metabolites showed significant correlations with maternal serum testosterone levels. Nine differential metabolites were shared between the placenta and umbilical cord serum, which also shared metabolic pathways, including ABC transporters and aminoacyl-tRNA biosynthesis, potentially influencing maternal-fetal interactions.

CONCLUSION

This study identifies the metabolomic profile and key pathways in maternal-fetal communication during PCOS pregnancies.

Angelica sinensis polysaccharide as potential protectants against recurrent spontaneous abortion: focus on autophagy regulation

Introduction

Recurrent spontaneous abortion (RSA) represents a significant clinical challenge, with its underlying mechanisms yet to be fully elucidated. Despite advances in understanding, the precise pathophysiology driving RSA remains unclear. Angelica sinensis, a traditional herbal remedy, is frequently used as an adjunctive treatment for miscarriage. However, it remains uncertain whether its primary active component, Angelica sinensis polysaccharide (ASP), plays a definitive role in its therapeutic effects. The specific function and mechanism of ASP in the context of RSA require further investigation.

Methods

In this study, we sought to evaluate autophagy levels at the maternal-fetal interface in RSA patients and in an RSA mouse model treated with ASP, complemented by a comprehensive metabolomic analysis. Autophagy flux in the decidua was compared between eight RSA patients and eight healthy pregnant women. Additionally, changes in autophagy flux were assessed in an RSA mouse model following ASP treatment, with embryos and placental tissues collected for subsequent metabolomic profiling.

Results

Our results revealed a significant reduction in Beclin 1 protein levels in the decidua of RSA patients compared to the normal pregnancy group. Conversely, ASP treatment in the RSA mouse model restored autophagy-related protein expression, including ATG7, ATG16L, and Beclin 1, to levels higher than those observed in the untreated RSA group. Metabolomic analyses further identified significant changes in phosphatidylethanolamine levels between ASP-treated and control groups, with differential metabolites enriched in pathways related to glycolysis/gluconeogenesis, glycerolipid metabolism, and glycine, serine, and threonine metabolism. Functional assays revealed that ASP enhances trophoblast cell proliferation, migration, and invasion.

Conclusion

In summary, our findings demonstrate diminished autophagy activity in RSA patients, while ASP appears to restore autophagy and regulate key metabolic pathways, including glycolysis/gluconeogenesis. These results provide new insights into the protective mechanisms of ASP in RSA, suggesting its potential as a therapeutic intervention for this condition.

AMPK Phosphorylates LMX1b to Regulate a Brainstem Neurogenic Network Important for Control of Breathing in Neonatal Mice

Ventilatory drive is modulated by a variety of neurochemical inputs that converge on spatially oriented clusters of cells within the brainstem. This regulation is required to maintain energy homeostasis and is essential to sustain life across all mammalian organisms. Therefore, the anatomical orientation of these cellular clusters during development must have a defined mechanistic basis with redundant genomic variants. Failure to completely develop these features causes several conditions including apnea of prematurity (AOP) and sudden infant death syndrome (SIDS). AOP is associated with many adverse outcomes including increased risk of interventricular hemorrhage. However, there are no pharmacological interventions that reduce SIDS and AOP prevalence by promoting brainstem development. AMP-activated protein kinase (AMPK) is a kinase that regulates ventilatory control to maintain homeostasis. This study identifies a signaling axis in which the pharmacological activation of AMPK in vivo via metformin in brainstem ventilatory control centers results in the phosphorylation of LIM homeobox transcription factor 1-beta (Lmx1b), a key player in dorsal-ventral patterning during fetal development. The phosphorylation of Lmx1b transactivates a neurogenic interactome important for the development and regulation of ventilatory control centers. These findings highlight the potential for metformin in the treatment and prevention of AOP.

Pregnancy Metabolic Adaptation and Changes in Placental Metabolism in Preeclampsia

Pregnancy is a unique physiological state in which the maternal body undergoes a series of changes in the metabolism of glucose, lipids, amino acids, and other nutrients in order to adapt to the altered state of pregnancy and provide adequate nutrients for the fetus' growth and development. The metabolism of various nutrients is regulated by one another in order to maintain homeostasis in the body. Failure to adapt to the altered physiological conditions of pregnancy can lead to a range of pregnancy issues, including fetal growth limitation and preeclampsia. A failure of metabolic adaptation during pregnancy is linked to the emergence of preeclampsia. The treatment of preeclampsia by focusing on metabolic changes may provide new therapeutic alternatives.

Relevance of real-time analyzers to determine mitochondrial quality in endothelial cells and oxidative stress in preeclampsia

Oxidative stress and mitochondrial dysfunction are important elements for the pathophysiology of preeclampsia (PE), a multisystemic hypertensive syndrome of pregnancy, characterized by endothelial dysfunction and responsible for a large part of maternal and fetal morbidity and mortality worldwide. Researchers have dedicated their efforts to unraveling the intricate ways in which certain molecules influence both energy metabolism and oxidative stress. Exploring established methodologies from existing literature, shows that these investigations predominantly focus on the placenta, identified as a pivotal source that drives the changes observed in the disease. In this review, we discuss the role of oxidative stress in pathophysiology of PE, as well as metabolic/endothelial dysfunction. We further discuss the use of seahorse analyzers to study real-time bioenergetics of endothelial cells. Although the benefits are clear, few studies have presented results using this method to assess mitochondrial metabolism in these cells. We performed a search on MEDLINE/PubMed using the terms "Seahorse assay and endothelial dysfunction in HUVEC" as well as "Seahorse assay and preeclampsia". From our research, we selected 16 original peer-review papers for discussion. Notably, the first search retrieved studies involving Human Umbilical Vein Endothelial Cells (HUVECs) but none investigating bioenergetics in PE while the second search retrieved studies exploring the technique in PE but none of the studies used HUVECs. Additional studies are required to investigate real-time mitochondrial bioenergetics in PE. Clearly, there is a need for more complete studies to examine the nuances of mitochondrial bioenergetics, focusing on the contributions of HUVECs in the context of PE.

An integral role of mitochondrial function in the pathophysiology of preeclampsia

Preeclampsia (PE) is associated with high maternal and perinatal morbidity and mortality. The development of effective treatment strategies remains a major challenge due to the limited understanding of the pathogenesis. In this review, we summarize the current understanding of PE research, focusing on the molecular basis of mitochondrial function in normal and PE placentas, and discuss perspectives on future research directions. Mitochondria integrate numerous physiological processes such as energy production, cellular redox homeostasis, mitochondrial dynamics, and mitophagy, a selective autophagic clearance of damaged or dysfunctional mitochondria. Normal placental mitochondria have evolved innovative survival strategies to cope with uncertain environments (e.g., hypoxia and nutrient starvation). Cytotrophoblasts, extravillous trophoblast cells, and syncytiotrophoblasts all have distinct mitochondrial morphology and function. Recent advances in molecular studies on the spatial and temporal changes in normal mitochondrial function are providing valuable insight into PE pathogenesis. In PE placentas, hypoxia-mediated mitochondrial fission may induce activation of mitophagy machinery, leading to increased mitochondrial fragmentation and placental tissue damage over time. Repair mechanisms in mitochondrial function restore placental function, but disruption of compensatory mechanisms can induce apoptotic death of trophoblast cells. Additionally, molecular markers associated with repair or compensatory mechanisms that may influence the development and progression of PE are beginning to be identified. However, contradictory results have been obtained regarding some of the molecules that control mitochondrial biogenesis, dynamics, and mitophagy in PE placentas. In conclusion, understanding how the mitochondrial morphology and function influence cell fate decisions of trophoblast cells is an important issue in normal as well as pathological placentation biology. Research focusing on mitochondrial function will become increasingly important for elucidating the pathogenesis and effective treatment strategies of PE.

Glycolysis: A fork in the path of normal and pathological pregnancy

Glucose metabolism is vital to the survival of living organisms. Since the discovery of the Warburg effect in the 1920s, glycolysis has become a major research area in the field of metabolism. Glycolysis has been extensively studied in the field of cancer and is considered as a promising therapeutic target. However, research on the role of glycolysis in pregnancy is limited. Recent evidence suggests that blastocysts, trophoblasts, decidua, and tumors all acquire metabolic energy at specific stages in a highly similar manner. Glycolysis, carefully controlled throughout pregnancy, maintains a dynamic and coordinated state, so as to maintain the homeostasis of the maternal-fetal interface and ensure normal gestation. In the present review, we investigate metabolic remodeling and the selective propensity of the embryo and placenta for glycolysis. We then address dysregulated glycolysis that occurs in the cellular interactive network at the maternal-fetal interface in miscarriage, preeclampsia, fetal growth restriction, and gestational diabetes mellitus. We provide new insights into the field of maternal-fetal medicine from a metabolic perspective, thus revealing the mystery of human pregnancy.