Fig. 5: MiR-503-322 promotes pancreatitis by inhibiting zymogen secretion and acinar cell proliferation.

A Extraction of fresh acinar cells from 8-week-old WT and PKI/WT male mice, in vitro stimulation with caerulein for 30 min and determination of amylase content in the supernatant. n = 3. B, C Amylase levels after calibration of total content release from acinar cells of 12-week WT and KO male mice (B) and 12-week and 1.5-year C57BL/6 J male mice (C) after 30 min of stimulation with caerulein. n = 3. D Pancreatic acini from WT or EKI mice, after 48 h tamoxifen induction, were incubated with or without caerulein (0.01 μM) for 30 min. Cells were then harvested, stained for F-actin (red) and nuclei (blue), and imaged by laser confocal microscopy. Micrographs of untreated and caerulein-pretreated acini are shown. n = 3 independent experiments. E Representative confocal images of WT and PKI/WT male mice acini after incubation with BziPAR for 30 min at 37 °C. n = 3 independent experiments. F Detection of serum trypsin activity levels in 16-week WT and PKI/WT male mice and EKI after Tamoxifen injection 5 days. n = 5. G Quantitation of the number of proliferating acinar cells of 8-week WT and PKI/WT male mice; 28 days after tamoxifen induction in WT and EKI male mice; 4 days after caerulein-induced AP in 12-week WT and KO male mice and 12-week and 1.5-year-old male mice. n = 3–5 mice per group. n = 5 mice. H–J Representative sections of immunofluorescence staining of amylase (red) and proliferating cell nuclear antigen (PCNA) (green) in pancreatic sections from 8-week WT and PKI/WT male mice (H), 28 days after tamoxifen induction in WT and EKI male mice (I), 4 days after caerulein-induced AP in 12-week WT and KO male mice (J). Arrows indicate proliferating acinar cells; asterisks are proliferating interstitial cells. n = 5 mice. K Representative sections of immunofluorescence staining of PCNA (green) in pancreatic sections from 12-week and 1.5-year-old male mice. n = 5 mice. Arrows indicate proliferating acinar cells. Data are means ± SEM. Unpaired Student’s t tests were used to evaluate statistical significance. Source data are provided as a Source Data file.