Poster Topical Area: Energy and Macronutrient Metabolism
Location: Hall D
Poster Board Number: 406
Objective: The Aryl hydrocarbon receptor (AHR) translocates to the nucleus and binds to aryl hydrocarbon receptor nuclear translocator (ARNT) to regulate biological responses upon ligand activation. The aim of this study is to measure the effects of activation or inhibition of AHR activity on basal and glucose stimulated insulin secretion (GSIS) from clonal pancreatic ß-cells (INS-1) cultured under normal and glucolipotoxic (GLT) conditions (high glucose and fatty acid).
Methods: Insulin content and secretion is measured utilizing Homogeneous Time Resolved Fluorescence (HTRF) assay kit from cisbio. INS-1 cells are cultured in RPMI media containing 5mM and 11mM glucose. Cells are pre-incubated with the receptor agonist (FICZ) and antagonist (CH223191) for 96 hours. Insulin secretion is measured over 2 hrs and reported as ng/million cells. Intracellular lipid is measured by fluorescence after Nile red staining.
Results: Incubation of INS-1 cells with 11mM glucose and fatty acid increased lipid droplets, basal insulin secretion and inhibited GSIS compared to cells cultured in 4mM glucose, characteristic of GLT. INS-1 cells cultured in 5 or 7 mM glucose and treated with the AHR agonist (1.25-10 nM) exhibited increased lipid without a significant effect on insulin secretion. INS-1 cells cultured at 11 mM glucose and treated with antagonist had decreased lipid content and improved insulin secretion compared to cells cultured in 11 mM glucose alone.
Conclusions: The AHR may play a role in the development of GLT in pancreatic ß-cells cultured in excess nutrients.