An in vitro method to study pancreatic acinar cells and centroacinar cells: Co-culture of rat pancreatic acinar cells AR42J and human pancreatic ductal epithelial cells HPDE6-C7

Background: This study is aimed at creating a new co-culture model to study the interactions between centroacinar cells (CACs) and pancreatic acinar cells (PACs), as reliable in vitro systems to reproduce their in vivo interactions are limited. Objective: To create a reliable in vitro co-culture model to study CAC–PAC interactions in both healthy and pathological settings, utilizing human pancreatic ductal epithelial cells HPDE6-C7 and rat pancreatic acinar cells AR42J. Methods: AR42J cells were gradually acclimated to the growth conditions of HPDE6-C7 cells before co-culture. Caerulein (CAE) was used to cause acute pancreatitis (AP) in both co-cultured cells and rats. Brightfield microscopy was used to analyze co-cultured cells after pancreatic tissues were stained with hematoxylin and eosin. Using transmission electron microscopy (TEM), ultrastructural characteristics such as gap junctions (GJs) and tight junctions (TJs) were assessed and contrasted with in vivo PACs and CACs. Immunofluorescence was used to measure microfilaments (MF) and the TJ protein zonula occludens-1 (ZO-1). Results: Co-cultured cells showed normal morphology, and AR42J cells grew steadily during adaptation. TEM investigation revealed endoplasmic reticulum (ER) dilatation, nuclear condensation, and mitochondrial enlargement. While AR42J cells in the CAE group grew longer and took on a spindle-like form, HPDE6-C7 cells showed mitochondrial vacuolization. TJs and GJs were enlarged in both cell types, which is consistent with alterations seen in rat PACs and CACs. Immunofluorescence showed punctate MF distribution around AR42J nuclei and network-like MF structures in HPDE6-C7 cells, which is consistent with in vivo results. Conclusion: Co-culture model provides a reliable in vitro system for researching pancreatic cellular interactions and material exchange since it faithfully replicates PAC–CAC interactions seen in vivo.