FIG. 7.

Effect of IL-1RA, GLP-1, or anti–TNF-α on rat primary β-cells exposed to conditioned medium. Conditioned media and abbreviations as described in the legend to Fig. 3. Rat primary β-cells were treated 48 h with IL-1RA (1 μg/mL) and conditioned medium. A: BrdU was added during the last 24 h to measure proliferation. B: Conditioned medium added for the last 24 h and cell death was measured by TUNEL. C: Rat primary β-cells were treated 48 h with conditioned medium, with or without GLP-1 (100 nmol/L), and BrdU was added the last 24 h to measure proliferation. D: Rat primary β-cells were treated 48 h with or without GLP-1, and conditioned medium was added for the last 24 h. Cell death was measured as described. n = 3 independent experiments. *P < 0.05; **P < 0.01. E: Insulin secretion was measured using rat primary β-cells treated for 24 h with the different conditioned media with or without TNF-α blockade (2 ng/mL Ethanercept) and then incubated for 60 min at 2.8 mmol/L glucose (open bars) followed by 60 min at 16.7 mmol/L glucose (closed bars); *P < 0.05. F and G: Rat primary β-cells treated with the different conditioned media with or without Ethanercept and were used to assess cell death using TUNEL assay (F) and cell proliferation (G) as described. n = 4 independent experiments; *P < 0.05 for TNF-α blockade. CTRL, control.