Epigenetic regulation by WTAPP1 promotes trophoblast dysfunction in gestational diabetes via CNR1/NF-κB activation

Gestational diabetes mellitus (GDM) poses significant risks to maternal and fetal health, necessitating exploration of novel molecular mechanisms. Clinical data from placental tissues from 33 GDM patients and 30 controls revealed Wilms tumor 1 associated protein (WTAP) pseudogene 1 (WTAPP1) was significantly upregulated in GDM, correlating with fasting glucose levels. In vitro, high glucose (25 mM) triggered oxidative stress (manifested by increased MDA, reduced GSH/GSSG ratio, and decreased CAT and SOD activity), inflammation (evidenced by elevated secretion of IL-1β, IL-6, TNF-α, and MCP-1), and apoptosis (along with upregulated cleaved caspase-3 or Bax, and downregulated Bcl-2) in trophoblast cell HTR-8/Svneo, while WTAPP1 knockdown partially restored viability, reduced apoptosis, and mitigated inflammatory cytokines and oxidative markers. Mechanistically, WTAPP1 promoted cannabinoid receptor 1 (CNR1) expression via WTAP-mediated m6A methylation, stabilizing CNR1 mRNA and activating the NF-κB signaling, as evidenced by increased phosphorylated IkBα and nuclear p65. Rescue experiments confirmed that CNR1 overexpression reversed the protective effects of WTAPP1 knockdown on high-glucose-induced damage in HTR-8/Svneo cells, while NF-κB inhibition by BAY-11-7085 attenuated high glucose-induced damage. This study unveils a novel WTAPP1/WTAP-m6A-CNR1-NF-κB axis driving trophoblast cell injury in GDM, highlighting WTAPP1 as a potential therapeutic target for hyperglycemia-induced placental injury.