Mechanism of trypsin-mediated differentiation of pancreatic progenitor cells into functional islet-like clusters.

Background: Endogenous regeneration of pancreatic islet β-cells is a path to cure both type 1 and advanced type 2 diabetes. Pancreatic cancer cell line-1 (PANC-1), a human pancreatic islet progenitor cell line, can be induced by trypsin to differentiate into insulin-secreting islet-like aggregates (ILAs). However, the underlying mechanism has not been explored.

Aim: To explore the mechanism and signaling pathway of trypsin-induced differentiation of islet progenitor cells into insulin-secreting cells.

Methods: PANC-1 cells were induced by trypsin to form ILAs and differentiate into insulin-secreting cells. Clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 knockout and small interfering RNA knockdown techniques were used to investigate membrane proteins and downstream signaling pathways involved in the process.

Results: The extracellular domain of membrane receptor E-cadherin hydrolyzed by trypsin induced the aggregation of PANC-1 cells and stimulated E-cadherin-recruited casein kinase-1γ3, which specifically phosphorylated the Ser655/Thr658 site of α-catenin in the cadherin-catenin complex, participating in the process of PANC-1 differentiation and affecting the maturation of differentiated ILAs.

Conclusion: The current study reveals the mechanism by which trypsin promotes PANC-1 cell differentiation into islet-like cells, providing a novel approach for endogenous islet β-cell regeneration.