Fig 1: GLP-2 secretion from isolated human islets. Isolated human islets were cultured on ECM-coated dishes (A–C) for 72h or during 49 h (C) with 5.5 mM glucose (control; C), 22.2 mM glucose (HG), 0.5 mM palmitate (Pal), a combination of HG/Pal or cytokines 2 ng/ml IL-1ß/1,000 U/ml IFN-? (IL/IF), in the absence (control) or presence of 30 nM linagliptin, or (D, E) for 24h with 5.5 mM glucose (control; C) or 20 µg/ml LPS in the absence (control) or presence of 10 µM TLR4 inhibitor TAK-242, followed by an ELISA assay of the cell culture supernatants for active GLP-2. Data are normalized to active GLP-2 secretion at untreated control conditions (corresponding to 1.5 ± 0.3 ng/100 islets into the 2 ml culture medium) and shown as means ± SEM from n = 4 (A, B, E) or 8 (D) different human islet isolations. (C) Active GLP-1 and GLP-2 shown as means ± SEM were analyzed from three different islet isolation; data of active GLP-1 are reproduced and thus are transformative from our earlier study (6), where secreted proteins were analyzed during a 49-hour culture of 60 human islets. *p < 0.05 diabetogenic conditions vs. control, **p < 0.05 linagliptin or TAK-242 vs. vehicle control; by paired two-tailed t-test.