Fig. 6. GLP-1R biased signalling and trafficking studies. (a) Cyclic AMP (cAMP) and β-arrestin-2 (βarr2) responses in PathHunter CHO–GLP-1R cells, 30 min stimulation, all ligands and pathways run in parallel, results normalized to global maximum responses (cAMP) or GLP-1–NH2 (2) maximal response (βarr2), 4-parameter fit shown, n = 5 independent experiments. (b) Confocal analysis of SNAP-GLP-1R internalization in SNAP-GLP-1R-expressing INS-1 832/3 cells labeled with SNAP-Surface 549 probe (red) for 30 min and then stimulated with 10 nM of the indicated ligand for a further 30 min. Nuclei (DAPI), blue; size bars, 10 μm. (c) Insulin secretion in INS-1 832/3 cells, 16 h stimulation at 11 mM glucose, all ligands run in parallel, normalised to basal response in each assay, 3-parameter fit shown, n = 5 independent experiments, Emax compared by 2-way repeat measures ANOVA with Tukey's test.
