The Serotonergic and Cholinergic Signaling Pathways Drive Gastric Precancerous Lesions and Its Potential Mechanism

Gastric cancer (GC) is a leading lethal malignancy globally. Gastric precancerous lesion (GPL) represents a critical step in GC, but its neural regulatory mechanisms remain largely unclear. We combined bioinformatics, patch-clamp recording, immunofluorescence, and chemogenetics to investigate serotonergic and cholinergic signaling in GPL. An N-methyl-N-nitrosourea (MNU) -induced mouse model was used for in vivo validation. High 5-HTR1D expression correlated with poor survival in gastric adenocarcinoma patients and was upregulated in AGS and MKN45 cells, as well as in gastric tissues of GPL mice. 5-HT evoked non-selective cation currents involving 5-HTR1D and TRPV4 in gastric epithelial and cancer cells, as supported by both pharmacological inhibition and siRNA-mediated TRPV4 knockdown. Blockade of 5-HTR1D or TRPV4 attenuated intestinal metaplasia and dysplasia, and this improvement was accompanied by reduced AKT/mTOR activation in GPL mice. Increased gastric M3R/5-HT co-localization was associated with elevated acetylcholine and overactivated cholinergic neurons in the dorsal motor nucleus of the vagus (DMV). Chemogenetic inhibition of DMV cholinergic neurons decreased ChAT and 5-HT levels and alleviated gastric pathology in GPL mice. These findings suggest that 5-HT/5-HTR1D signaling may promote TRPV4-involved cation currents, contributing to mucosal pathology and intestinal metaplasia in GPL model mice, whereas DMV cholinergic neurons projecting to the stomach may facilitate gastric 5-HT secretion and thereby potentially contribute to GPL progression. This work establishes a novel neuro-epithelial network linking vagal cholinergic output to serotonergic signaling that may be involved in GPL progression, providing potential targets for prevention and intervention.