The genomic analysis of endometrial mitochondrial DNA copy number variation on recurrent implantation failure

Melatonin affects trophoblast epithelial-to-mesenchymal transition and oxidative damage resistance by modulating GDF15 expression to promote embryo implantation

Melatonin is widely observed in the female reproductive system and regulates trophoblast cell functions, but its effects on embryo implantation and underlying mechanisms are not well understood. By constructing an in vitro embryo culture model, we found that melatonin enhances migration and implantation in human and mouse trophoblast cells. It also significantly promoted HTR-8/SVneo cell proliferation, inhibited apoptosis, enhanced migration, and mitigated oxidative damage. Further investigation revealed that melatonin promoted trophoblast cell migration and increased the in vitro implantation rate of HTR-8/SVneo spheroids by promotes epithelial-mesenchymal transition (EMT) via the growth differentiation factor 15 (GDF15)-mothers against decapentaplegic homolog 2/3 (SMAD2/3) pathway. Additionally, melatonin increased the levels of glutathione peroxidase 4 (GPX4) and glutathione (GSH) in HTR-8/SVneo cells by upregulating the expression of GDF15, inhibiting reactive oxygen species (ROS) accumulation, and increasing mitochondrial membrane potential, thus suppressing apoptosis during oxidative stress. In conclusion, melatonin promotes EMT in trophoblast cells via GDF15-SMAD2/3 pathway and partially induces the expression of GPX4 through GDF15 to enhance oxidative damage resistance in trophoblast cells. These findings highlight melatonin's regulatory role in embryo implantation and suggest new avenues for exploring its biological effects in reproduction and clinical applications.

Epidemiologically relevant phthalates affect human endometrial cells in vitro through cell specific gene expression changes related to the cytoskeleton and mitochondria

Phthalates are endocrine disrupting chemicals (EDCs) found in common consumer products such as soft plastics and cosmetics. Although the knowledge regarding the adverse effects of phthalates on female fertility are accumulating, information on the hormone sensitive endometrium is still scarce. Here, we studied the effects of phthalates on endometrial cell proliferation and gene expression. Human endometrial primary epithelial and stromal cells were isolated from healthy fertile-aged women (n=3), and were compared to endometrial cell lines T-HESC and Ishikawa. Three different epidemiologically relevant phthalate mixtures were used, defined by urine samples in the Midlife Women Health Study (MWHS) cohort. Mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was used as a single phthalate control. Cells were harvested for proliferation testing and transcriptomic analyses after 24 h exposure. Even though all cell models responded differently to the phthalate exposures, many overlapping differentially expressed genes (DEGs, FDR<0.1), related to cell adhesion, cytoskeleton and mitochondria were found in all cell types. The qPCR analysis confirmed that MEHHP significantly affected cell adhesion gene vinculin (VCL) and NADH:ubiquinone oxidoreductase subunit B7 (NDUFB7), important for oxidative phosphorylation. Benchmark dose modelling showed that MEHHP had significant concentration-dependent effects on cytoskeleton gene actin-beta (ACTB). In conclusion, short 24 h phthalate exposures significantly altered gene expression cell-specifically in human endometrial cells, with six shared DEGs. The mixture effects were similar to those of MEHHP, suggesting MEHHP could be the main driver in the mixture. Impact of phthalate exposures on endometrial functions including receptivity should be addressed.

Effect of prolactin on cytotoxicity and oxidative stress in ovine ovarian granulosa cells

Background

Prolactin (PRL) has been reported to be associated with oxidative stress, which is an important contributor leading to cell apoptosis. However, little is known about the mechanisms underlying the effects of PRL on cytotoxicity and oxidative stress in ovine ovarian granulosa cells (GCs).

Methods

Ovine ovarian GCs were treated with 0, 4, 20, 100 and 500 ng/mL of PRL. Then, the cytotoxicity, cell viability, malondialdehyde (MDA), reactive oxygen species (ROS), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) of GCs were detected. Additionally, 500 ng/mL PRL was chosen as the high PRL concentration (HPC) due to its high cytotoxicity and oxidative stress. Proteomic and metabonomic were performed to examine the overall difference in proteins and metabolic pathways between C (control: 0 ng/mL PRL) and P groups (500 ng/mL PRL).

Results

The results indicated that GCs treated with 4 ng/mL PRL significantly decreased (P < 0.05) the cytotoxicity, ROS and MDA, increased (P < 0.05) the cell viability, SOD and T-AOC, and the GCs treated with 500 ng/mL PRL showed the opposite trend (P < 0.05). Supplementation with 500 ng/mL PRL significantly increased the proteins of MT-ND1, MAPK12, UBA52 and BCL2L1, which were enriched in ROS and mitophagy pathways. Pathway enrichment analysis showed that the pentose phosphate pathway was significantly enriched in the P group.

Conclusion

A low concentration of PRL inhibited cytotoxicity and oxidative stress. HPC induced oxidative stress in ovine ovarian GCs via the pentose phosphate pathway by modulating the associated proteins MT-ND1 in ROS pathway and UBA52, MAPK12 and BCL2L1 in mitophagy pathway, resulting in cytotoxicity.

Progress of oxidative stress in endometrium decidualization

The difficulty in maintaining the balance between oxides and antioxidants causes a phenomenon named oxidative stress. Oxidative stress often leads to tissue damage and participates in the pathogenesis of a series of diseases. Decidua provides the 'soil' for embryo implantation, and the normal decidualization shows the characteristics of strong antioxidation. Once the mechanism of antioxidant stress goes awry, it will lead to a series of pregnancy-related diseases. In recent years, more and more studies have shown that oxidative stress is involved in pregnancy-related diseases caused by abnormal decidualization of the endometrium. In order to have a more comprehensive understanding of the role of oxidative stress in decidual defect diseases, this paper reviews the common decidual defect diseases in conjunction with relevant regulatory molecules, in order to arouse thinking about the importance of oxidative stress, and to provide more theoretical basis for the aetiology of decidual defects.