The following is a summary of “Glucagon-like Peptide-2 Acutely Enhances Chylomicron Secretion in Humans Without Mobilizing Cytoplasmic Lipid Droplets,” published in the May 2023 issue of Endocrinology & Metabolism by Abdul, et al.
For a study, researchers sought to investigate further the mechanism by which glucagon-like peptide-2 (GLP-2) enhances intestinal lipid mobilization and chylomicron (CM) secretion by examining intracellular cytoplasmic lipid droplets (CLDs) in human intestinal biopsies.
Participants were administered a single subcutaneous dose of either placebo or GLP-2, 5 hours after ingesting a high-fat bolus. Plasma samples were collected to measure lipid and lipoprotein concentrations for 3 hours. In a subset of participants, duodenal biopsies were obtained 1 hour after placebo or GLP-2 administration for transmission electron microscopy and proteomic analysis.
GLP-2 administration significantly increased plasma triglycerides by 46% (P = 0.009), primarily in CM-sized particles by 133% (P = 0.003), without causing a reduction in duodenal CLD size or number. Proteomic analysis identified several proteins of interest that warrant further investigation to understand their potential role in GLP-2-mediated CM secretion.
In contrast to glucose, which mobilizes enterocyte CLDs and enhances CM secretion, GLP-2 acutely increased plasma CM levels without significant mobilization of CLDs in the intestine. The findings supported previous research indicating that GLP-2 does not directly act on enterocytes to enhance CM secretion but likely mobilizes already secreted CMs in the lamina propria and lymphatics. Further studies were needed to elucidate the precise mechanisms involved in GLP-2-mediated CM secretion.