Figure 8. mTORC1 signaling in neonate and adult Akita islets.

(a) Western blot analysis of S6 and 4EBP1 phosphorylation in islets of neonate (P19-21) and adult wild-type and Akita mice. Quantification of phosphorylated S6 in neonate Akita compared to control islets is shown (n = 3, each sample is a pool of islets from 4 to 7 mice); (b) immunostaining for phospho-S6 on pancreatic sections of P1-2, P19-21 and adult Akita mice and age-matched controls and quantifications of the percentage of S6⁺ β-cells (P1-2: n = 4 mice in each group; 1159 WT and 1655 Akita β−cells; P19-21: n = 6 mice in each group; 2259 WT and 1567 Akita β−cells; adult: n = 4–5 mice in each group; 2391 WT and 1383 Akita β-cells). Islet boundaries are marked by dotted line; (c) adult Akita mice were treated with 25 mg/kg dapagliflozin in drinking water for 72 hr. Blood glucose in dapagliflozin-treated Akita mice was ~ 200 mg/dl compared to ~ 500 mg/dl in control Akita mice. Pancreatic sections were immunostained for insulin and phospho-S6 (n = 3 mice in each group). *p<0.05, **p<0.01, ****p<0.0001.

Figure 8—figure supplement 1. Effects of chemical chaperones on mTORC1 activity in neonate Akita islets and controls.

(a) islets of P16-19 Akita and wild-type (WT) mice were treated with 250 μmol/l TUDCA or 2.5 mmol/l PBA for 48 hr followed by western blotting for BiP and phosphorylated S6 (n = 3, each sample is a pool of islets from 4 to 9 mice); (b) effects of TUDCA on β-cell proliferation in neonate Akita mice (P18-20). TUDCA (1 mg/kg) was injected IP twice daily for 48 hr followed by immunostaining of pancreatic sections for Ki67 and insulin (n = 4–6 mice in each group; 1403 control Akita and 2183 TUDCA-treated Akitaβ-cells). **p<0.01.