Ablation of PTP1B increases proliferation in in vivo β-cells and alters pancreas morphometry in PTP1B ⁻/⁻ mice.

Morphometric analysis of fixed paraffin embedded pancreas from PTP1B ⁻/⁻ and WT mice (n = 5–7 animals per group). A) Level of proliferating β-cells (ki67+/insulin+) from PTP1B ⁻/⁻ and WT mice. Representative images showing immunostaining for ki67 (green), insulin (red), and merged images together with Dapi for nuclei (blue) on pancreatic sections from PTP1B ⁻/⁻ and WT mice. B) Levels of apoptotic β-cells (caspase3+/insulin+) from PTP1B ⁻/⁻ and WT mice. Representative images showing immunostaining for insulin (red), Caspase3 (green), and Dapi for nuclei (blue) on pancreatic sections from PTP1B ⁻/⁻ and WT mice. C) Pancreas weight normalized by body weight. D) Number of islets, over the total pancreatic area (µm²) studied. E) Distribution of islets on the basis of their size, expressed as the percentage of a given size, over the total pancreatic area (µm²) studied. F) β-cell mass is quantified blindly as β-cell volume density, multiplied by pancreas weight. G) α-cell mass is quantified blindly as α-cell volume density, multiplied by pancreas weight. All bars represent mean±SEM * p<0.05 PTP1B ⁻/⁻ vs WT.