Fig. 5: In vivo real-time monitoring of β-cell proliferation during high fat loading.

A Time courses of luciferase activity in plasma of 3 months old male iβKi67p-Gluc mice on C57BL/6 background fed high fat-diet (HFD, red) relative to those on week 0. iβKi67p-Gluc mice which fed normal chow (NC, blue) served as controls. Solid lines and dotted lines indicate average and individual values, respectively. B The area under the curve of the plasma luciferase activity of HFD or NC during the experimental period. C Ki67⁺/Ins⁺ cell ratios in insulin positive cells of 3 months old male iβKi67p-Gluc mice on week 0 and 8 after high fat loading relative to those on week 0; representative images are shown in the right two panels. Each arrowhead denotes a Ki67⁺/Ins⁺ cell. Scale bars denote 50 µm. D Linear relationship between relative luciferase activity and %Ki67⁺/Ins⁺ β-cells. Open circles indicate relative luciferase activity and %Ki67⁺/Ins⁺ β-cells in individual iβKi67p-Gluc mice after high fat loading relative to those on week 0 (r = 0.891, P = 0.0013). Data are presented as means ± SEM. A, B *p < 0.05, **p < 0.01, assessed by one-way repeated-measures ANOVA followed by Tukey multiple comparison test for the various time points A, two-sided unpaired t-test B, or two-sided paired t-test C. Pearson’s correlation coefficient (two-sided) was used to determine the correlation D. n = 8 independent animals for HFD, n = 7 independent animals for NC, from five independent experiments. C, D n = 5 independent animals for HFD, n = 4 independent animals for NC, from three independent experiments. Exact P values are A P = 0.024 (week 0 vs. week 8); B P = 0.0018; C P = 0.00023. Source data are provided as a Source Data file.