Fig. 4.

The SeP-neutralizing Ab improved insulin secretion impaired by SeP. a SeP-neutralizing mAb AE2 improved pancreas insulin levels. After administration of AE2 and hSeP, pancreas tissues were homogenized and analysed by western blotting (n = 5–8, means ± s.e.m.). Non-specific bands are indicated by an x. **P < 0.01, Tukey-ANOVA. *P < 0.05, Student's t-test. b, c Neutralizing mAb AE2 improved pancreatic β-cell area. Pancreas tissues from AE2- and hSeP-treated mice were examined immunohistochemically using anti-insulin Ab (indicative of β-cells) and anti-hSeP Ab b. Cell nuclei were stained with DAPI (blue). The distribution of hSeP in pancreatic β-cells was decreased in mice administered AE2. The proportion of β-cell area to total pancreatic area was determined (c, n = 3, means ± s.e.m.). **P < 0.01, Tukey-ANOVA. d Histochemical analysis of pancreas tissues from AE2- and hSeP-treated mice using haematoxylin and eosin stain (HE), anti-insulin Ab (green) and Glucagon (red, indicative of α-cells). Scale bars = 100 µm (b, d). e Insulin secretion of isolated rat islets was significantly decreased by excess human SeP. Isolated rat islets were incubated with 10 µg/mL hSeP for 24 h, and then insulin secretion induced by high glucose condition was evaluated, as described in the Methods (n = 3, means ± s.d.). **P < 0.01, Student's t-test. f Insulin secretion of isolated rat islets was significantly improved by AE2. Isolated rat islets were incubated with 10 µg/mL hSeP in the presence of AE2 mAb or control IgG (500 µg/mL) for 24 h, and then insulin secretion was evaluated (n = 3, means ± s.d.). *P < 0.05, **P < 0.01, Tukey-ANOVA