Intestinal extracellular vesicles are altered by vertical sleeve gastrectomy

Area of Science:

• Gastroenterology
• Molecular Biology
• Metabolic Surgery

Background:

• Bariatric surgery, particularly vertical sleeve gastrectomy (VSG), is highly effective for obesity but its molecular mechanisms remain unclear.
• Extracellular vesicles (EVs) are key mediators of intercellular communication, carrying various biomolecules.
• Understanding the role of intestinal EVs in VSG's effects is crucial for elucidating its therapeutic actions.

Purpose of the Study:

• To investigate the impact of VSG on the proteomic composition of small intestinal extracellular vesicles (EVs) in a mouse model.
• To evaluate the functional effects of VSG-derived EVs on intestinal enteroids and bacterial cultures.
• To assess the in vivo effects of VSG-derived EVs on host physiology and intestinal morphology.

Main Methods:

• Proteomic analysis of small intestinal EVs isolated from mice undergoing VSG or sham surgery.
• In vitro experiments treating enteroid and bacterial cultures with EVs.
• Intraduodenal administration of EVs to mice, followed by evaluation of body weight, glucose metabolism, and intestinal morphology.

Main Results:

• VSG significantly altered the protein composition of intestinal EVs compared to sham surgery.
• VSG-derived EVs reduced enteroid survival and promoted bacterial proliferation in vitro.
• In vivo administration of VSG-EVs led to reduced ileal villi length and decreased epithelial proliferation in the jejunum and ileum, without altering body weight or glucose metabolism.

Conclusions:

• Vertical sleeve gastrectomy induces significant remodeling of intestinal extracellular vesicle protein composition.
• VSG-derived EVs possess cytotoxic effects on intestinal epithelial cells and inhibit progenitor cell proliferation.
• Intestinal EVs may play a role in mediating some of the local intestinal effects of VSG.