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.