Nitrate Enhances Gastric Mucosa Defense and Repair Process in Ethanol-Induced Gastric Ulcer Rats via the Notch-Tff2 Pathway.

Gastric mucosal integrity is essential for maintaining systemic homeostasis, serving as the primary defense against external insults. Ethanol ingestion is a major clinical cause of gastric mucosal injury, yet effective prevention or treatment remains limited. This study investigates the protective role of nitrate against ethanol-induced gastric ulcers and its underlying mechanisms. In vivo, nitrate significantly ameliorated ethanol-induced gastric bleeding, edema, inflammation, and mucus layer thinning in rats, while strengthening the vascular endothelial barrier. Transcriptomic analyses and trefoil factor 2 (Tff2)-knockdown rats experiment identified Tff2 as the key gene responsible for mediating nitrate's protective effects against ethanol. In vitro, TFF2 was found to be a crucial target for nitrates, which enhance the migratory reparative capacities of human gastric epithelial cells. Further assays revealed that RBPJ regulates the TFF2 promoter, and NICD-RBPJ complex formation is critical for TFF2 transcriptional repression. We demonstrate for the first time that TFF2 is a central effector in nitrate-mediated gastric mucosal defense and repair and implicate the Notch signaling pathway in TFF2 regulation. These findings suggest nitrate exerts a protective effect on the gastric mucosa through multiple ways. TFF2 modulation as a potential preventive strategy for ethanol-induced gastric ulcers.