Figure 6.

Declined regenerative rate in TIF-IA^Δ/Δ mice with older onset of β-cell loss. (A and B) Immunostaining and quantification of insulin (green) and glucagon (red) expressing cells in the pancreata of TIF-IA^+/+ and TIF-IA^Δ/Δ mice at different time points post injection (A). β-cell number is increased gradually in mice injected at three-months, but at a slower rate compared tot he younger mice (B). (C) Reduction of blood glucose level takes place at a slower manner in older mice. (D) β-cell proliferation rate is increased in mice with the older onset ablation. (E) The relative abundance of bihormonal cells is similar in one- and 3 mo old injected mice. In both cases, their frequencies decrease by time following initial ablation. (F) Adaptive β-cell proliferation and α- to β-cell transdifferentiation contribute to β-cell regeneration in TIF-IA^Δ/Δ model. Bihormonal cells are shown in violet. mo.: months post injection. Scale bar: 25 μm. Values are presented by mean ± SEM. P-value <0.05: *, P-value <0.01 : **, P-value <0.001: ***. N >3 animals for each experimental condition.