The Role of Acetyl-CoA Metabolism in Maintaining the Synchronization of Human Trophoblast Stem Cells

Research Background and Purpose

The placenta is a crucial metabolic bridge between the mother and fetus during pregnancy, and its normal function is vital for the health of both. The placenta constantly differentiates through human trophoblast stem cells (HTSCs), forming multinucleated syncytiotrophoblasts (STBs), and through this process facilitates the exchange of substances between the mother and fetus. Although previous studies have highlighted the key role of metabolic pathways, especially glucose metabolism, in regulating stem cell fate and differentiation, the specific metabolic mechanisms are not yet fully understood. This study, based on this background, explores the role of Acetyl-CoA metabolism in maintaining histone acetylation during HTSC differentiation and synchronization, to reveal the regulatory mechanisms of trophoblast cell metabolic programming on maternal-fetal nutritional balance.

Paper Source

The authors of this paper include researchers Xin Yu, Hao Wu, Jiali Su, and others from the Institute of Zoology, Chinese Academy of Sciences, the Institute for Stem Cell and Regeneration, and the Beijing Institute of Stem Cell and Regenerative Medicine. The paper was published in Cell Stem Cell on September 5, 2024, and is published by Elsevier.

Research Process

Experimental Design and Research Process

This study used early human placental samples and in vitro cultured HTSCs. The research was conducted in the following stages:

1. Metabolic State Analysis: Single-cell RNA sequencing was used to analyze the expression changes of key enzymes of glucose metabolism in cytotrophoblasts (CTBs) and STBs during the first trimester of human placenta. It was found that HTSCs and CTBs gradually decrease from a high active glycolysis state to a basal level during synchronization.

2. Protein and Metabolite Analysis: Using immunofluorescence and immunohistochemistry, the expression levels of glycolytic enzymes and tricarboxylic acid cycle enzymes in CTBs and STBs were detected. The results showed that glycolytic enzymes (such as hexokinase 2, phosphofructokinase, etc.) were significantly higher in CTBs than in STBs. Mass spectrometry was used to analyze the levels of glycolysis-related metabolites, further verifying the active glucose metabolism state in CTBs and enhanced fatty acid metabolism in STBs.

3. Metabolic Inhibition Experiment: To study the role of basal glycolysis in HTSC synchronization, 2-deoxy-D-glucose (2-DG) and oxamate were used to inhibit key steps of glycolysis, and their effects on the expression of HTSC synchronization marker genes were observed. The results showed that the maintained basal level of glycolysis during HTSC differentiation is crucial for synchronization, and any inhibition leads to a significant decline in synchronization marker gene expression.

4. Acetic Acid Supplementation Experiment: By supplementing acetic acid to restore intracellular Acetyl-CoA levels in HTSCs, it was found that acetic acid significantly improved synchronization obstacles caused by glycolytic inhibition and restored the expression levels of synchronization-related genes. Combined with histone acetylation data, the study confirmed the critical regulatory role of Acetyl-CoA in the acetylation of histone H3 and H4.

5. RNA Sequencing Analysis: RNA sequencing results indicated that glycolytic inhibition leads to suppressed HTSC synchronization gene expression and induces inflammatory responses and metabolic stress. Acetic acid supplementation significantly reversed these abnormal gene expressions.

6. Histone Acetylation Analysis: Through Cut&Tag technology, the authors found that Acetyl-CoA derived from glycolysis maintained the acetylation of specific histone sites (such as H3K9/18/27 and H4K16), which are crucial for the regulation of synchronization-related gene promoter regions.

7. In Vivo Validation: An HTSC xenotransplantation model was used to further verify that temporary glycolytic defects permanently alter HTSC differentiation potential, leading to increased inflammatory responses that can be reversed by short-term acetic acid supplementation.

New Methods and Innovations

In this study, ^13C glucose isotope labeling was introduced into in vitro models to quantify the dynamic changes of glucose metabolism during HTSC differentiation. Combined with metabolomics, transcriptomics, and histone acetylation modification analysis, the critical regulatory mechanism of Acetyl-CoA on HTSC differentiation was revealed. Also, the HTSC metabolism defect was validated for the first time using an in vivo xenotransplantation model, demonstrating long-term impacts on placental development.

Research Results

1. Role of Glucose Metabolism in HTSC Differentiation: CTBs and HTSCs showed a significant decrease in glucose metabolism during synchronization, and the basal glycolysis level is essential for HTSC synchronization. Inhibition of glycolysis by 2-DG and oxamate resulted in a significant decline in the expression of synchronization marker genes (such as ERVFRD1, SYN1), indicating that glycolytic inhibition hinders HTSC synchronization.

2. Critical Role of Acetyl-CoA in Histone Acetylation: Acetic acid supplementation restored Acetyl-CoA levels, significantly reversing the decrease in histone acetylation levels caused by glycolytic inhibition. Specifically, the acetylation status of histone H3K9, H3K18, H3K27, and H4K16 sites plays a crucial regulatory role in the expression of synchronization genes.

3. Correlation Between Metabolic Stress and Inflammatory Response: Glycolytic inhibition not only hinders HTSC synchronization but also induces the expression of metabolic stress and inflammatory genes. Acetic acid supplementation effectively inhibited these stress and inflammation genes, indicating the importance of basal glycolysis in maintaining normal HTSC differentiation and function.

4. In Vivo Validation: Xenotransplantation experiments showed that even short-term glycolytic inhibition permanently damages HTSC differentiation potential, characterized by increased inflammatory response and reduced multinucleated STBs. Acetic acid supplementation significantly recovered these changes.

Research Conclusion and Significance

This study clarifies the essential role of basal glycolysis in HTSC synchronization. Acetyl-CoA is not only a core intermediate of cell metabolism but also plays an important regulatory role in determining the cell fate and differentiation of HTSCs by maintaining histone acetylation. Adequate Acetyl-CoA is significant for normal placental development and maternal-fetal nutritional balance. Understanding this mechanism provides a new scientific basis for preventing placental-related diseases (such as pregnancy-induced hypertension and fetal growth restriction).

Research Highlights and Innovations

1. Revealing the Metabolic Regulatory Role of Acetyl-CoA: This study systematically demonstrated for the first time the key role of Acetyl-CoA in HTSC synchronization, proposing the dual regulatory role of glycolysis-derived Acetyl-CoA on histone acetylation and gene expression.

2. Coupling Mechanism of Metabolism and Histone Modification: It was found that Acetyl-CoA regulates placental cell fate through the acetylation of specific histone sites (such as H3K9/18/27 and H4K16), providing a new perspective for understanding placental development and function through this metabolism-epigenetic coupling mechanism.

3. Irreversible Impact of Long-term Metabolic Defects: The study was the first to verify in an in vivo model that short-term glycolytic inhibition causes permanent damage to HTSC differentiation, implying the vulnerability of trophoblast cell metabolic balance and its profound impacts on maternal-fetal health.

4. Potential Clinical Value of Acetic Acid Supplementation: The research found that short-term acetic acid supplementation can effectively reverse HTSC synchronization obstacles caused by glycolytic inhibition, providing potential intervention methods for future treatment of placental dysfunction during pregnancy.

Scientific and Application Value of the Research

The metabolic programming mechanisms of HTSCs revealed in this study are critical for placental development and maternal-fetal nutritional balance, providing new insights into the pathogenesis of placental-related diseases (such as pregnancy-induced hypertension and fetal growth restriction). The study provides a new model of the role of glucose metabolism in the placental synchronization process, highlighting the core role of metabolic regulation in maintaining placental function. In the future, intervention measures based on this mechanism may offer new approaches to prevent and treat placental insufficiency and other related issues.