IGF2BP2 Mediated the Positive Effects of the NAD + in the Decidualization of the Human Endometrial Stromal Cells

Background The successful decidualization of the endometrium is crucial for human embryo implantation. Impaired decidualization leads to reduced endometrial receptivity and implantation failure. Nicotinamide adenine dinucleotide (NAD+), boosted by nicotinamide mononucleotide (NMN) supplementation, has been suggested to positively influence endometrial stromal cell decidualization. This study aimed to investigate the role and mechanism of NAD + in the decidualization of human endometrial stromal cells (hEnSCs). Methods In this study, we isolated primary hEnSCs from healthy donors and cultured them under three experimental conditions: a blank group without decidualization stimuli, a control group treated with traditional decidualization medium, and an experimental group supplemented with 200 µM NMN. We employed RNA sequencing and quantitative real-time PCR (qRT-PCR) to analyze differentially expressed genes and validate mRNA expression changes related to decidualization. Western blotting was carried to examine protein levels involved in cell cycle regulation and apoptosis pathways. Statistical analyses were performed using t-tests with a significance threshold of p < 0.05. Results We found that NAD + supplementation did not alter the initial phase of hEnSCs decidualization but significantly inhibited apoptosis in decidualizing cells. Importantly, we identified that the RNA-binding protein IGF2BP2 mediated the pro-decidualization effects of NAD+. IGF2BP2, by recognizing N6-methyladenosine (m6A) modifications on key mRNAs, enhanced their stability and expression. These target genes are primarily involved in DNA replication and cell cycle regulation, processes critical for establishing endometrial receptivity. Conclusions Our study reveals a novel IGF2BP2-mediated mechanism through which NAD⁺ promotes endometrial decidualization by enhancing the mRNA stability of genes critical for cell survival and proliferation. These findings not only provide new insights for improving embryo implantation outcomes in assisted reproductive technologies but also suggest a potential therapeutic strategy for disorders associated with impaired decidualization.