Figure 6. No evidence of acinar-to-islet transdifferentiation after cerulein-induced pancreatitis.
ElastaseCreERT2Tg/+Rosa26r+/– mice were treated with TAM for 3 weeks by subcutaneous continuous delivery pellet and subjected to a 2-day course of serial cerulein injections as described in Methods. (A–C) Severe exocrine inflammation but intact islets were evident 1 day after the initiation of treatment (A and B), with histologic recovery by 7 days (C). Cerulein-treated mice were randomized to receive daily injections of vehicle or Ex-4 (1 nmol/kg body wt i.p.) on day 3, the time of maximal Notch activation. (D–F) Tissues were harvested on day 7, and β-galactosidase activity (blue stain) and insulin immunoreactivity (red stain) were visualized. (D) Pancreas from a control mouse that received only PBS vehicle. (E and F) Pancreata from cerulein-treated mice that received vehicle (E) or Ex-4 (F). Original magnification, ×200.