The EndoC-ßH1 cell line is a valid model of human beta cells and applicable for screenings to identify novel drug target candidates.

OBJECTIVE: To characterize the EndoC-ßH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates. METHODS: EndoC-ßH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice. Cytokine induced apoptosis, glucolipotoxicity, and ER stress responses were assessed. Beta cell relevant mRNA and protein expression were investigated by qPCR and antibody staining. Hundreds of proteins or peptides were tested for their effect on insulin secretion and proliferation. RESULTS: Transplantation of EndoC-ßH1 cells restored normoglycemia in streptozotocin induced diabetic mice. Both in vitro and in vivo, we observed a clear insulin response to glucose, and, in vitro, we found a significant increase in insulin secretion from EndoC-ßH1 pseudoislets compared to monolayer cultures for both glucose and incretins. Apoptosis and ER stress were inducible in the cells and caspase 3/7 activity was elevated in response to cytokines, but not affected by the saturated fatty acid palmitate. By screening of various proteins and peptides, we found Bombesin (BB) receptor agonists and Pituitary Adenylate Cyclase-Activating Polypeptides (PACAP) to significantly induce insulin secretion and the proteins SerpinA6, STC1, and APOH to significantly stimulate proliferation. ER stress was readily induced by Tunicamycin and resulted in a reduction of insulin mRNA. Somatostatin (SST) was found to be expressed by 1% of the cells and manipulation of the SST receptors was found to significantly affect insulin secretion. CONCLUSIONS: Overall, the EndoC-ßH1 cells strongly resemble human islet beta cells in terms of glucose and incretin stimulated insulin secretion capabilities. The cell line has an active cytokine induced caspase 3/7 apoptotic pathway and is responsive to ER stress initiation factors. The cells' ability to proliferate can be further increased by already known compounds as well as by novel peptides and proteins. Based on its robust performance during the functionality assessment assays, the EndoC-ßH1 cell line was successfully used as a screening platform for identification of novel anti-diabetic drug candidates.

Hedgehog signaling is required for effective regeneration of exocrine pancreas.

Although both endocrine and the exocrine pancreas display a significant capacity for tissue regeneration and renewal, the existence of progenitor cells in the adult pancreas remains uncertain. Using a model of cerulein-mediated injury and repair, we demonstrate that mature exocrine cells, defined by expression of an Elastase1 promoter, actively contribute to regenerating pancreatic epithelium through formation of metaplastic ductal intermediates. Acinar cell regeneration is associated with activation of Hedgehog (Hh) signaling, as assessed by up-regulated expression of multiple pathway components, as well as activation of a Ptch-lacZ reporter allele. Using both pharmacologic and genetic techniques, we also show that the ability of mature exocrine cells to accomplish pancreatic regeneration is impaired by blockade of Hh signaling. Specifically, attenuated regeneration in the absence of an intact Hh pathway is characterized by persistence of metaplastic epithelium expressing markers of pancreatic progenitor cells, suggesting an inhibition of redifferentiation into mature exocrine cells. Given the known role of Hh signaling in exocrine pancreatic cancer, these findings may provide a mechanistic link between injury-induced activation of pancreatic progenitors and subsequent pancreatic neoplasia.