A gut reaction: effects of an e. coli-produced toxin on gut hormone regulation and gut physiology

Abstract

Enterotoxigenic Escherichia coli (ETEC) produces the heat-stable enterotoxin b (STb), which is responsible for secretory diarrhea in humans and animals. STb disrupts intestinal fluid homeostasis, epithelial barrier function, and promotes apoptosis. Glucagon-like peptide-2 (GLP2) is an intestinotrophic growth hormone secreted by enteroendocrine L-cells which enhances cellular proliferation, epithelial barrier function, and inhibits apoptosis. As many similarities are clear between GLP-2 production and secretion pathways and STb cell signaling mechanisms, this study aims to investigate the effects STb has on the physiology of in-vitro L-cells and the secretion of GLP-2. Enteroendocrine cells which secreted the highest amounts of growth hormone were found to be more resistant to STb intoxication. STb was found to enhance the secretion of GLP-2, potentially due to similar cellular mechanisms of hormone production and secretion and STb cell signaling. GLP-2 was found to inhibit the toxigenic effects of STb. Future work will elucidate the mechanism of this interaction. This work will support the use of GLP-2 therapies in enterotoxigenic related diseases.