Advancement in Understanding the Concept of Epithelial to Mesenchymal Transition in Pancreatic β-Cells: Implication in Diabetes

Distinct molecular processes are engaged during histogenesis, and Epithelial to Mesenchymal Transition (EMT) is one of the key evolutionarily conserved processes that facilitates organ development. Molecular pathways governing EMT are embedded within developmental programs and operate in cells of different tissues. Among varied cell types, EMT in pancreatic β-cells is of greater interest as the existence of EMT in these cells is highly debated. Although in vitro generation of human islet-derived mesenchymal progenitor cells has been proven beyond doubt, the existence of EMT in pancreatic β-cells in vivo remains enigmatic. Understanding the in-depth process of EMT in in vivo human β-cells is challenged by the limitations of lineage-tracing studies, which are otherwise feasible in mice. Exploring EMT of β-cells would greatly facilitate the generation of clinically relevant β-cells either by enhancing long-term in vitro culture of endogenous islets or by differentiation of pluripotent stem cells to mature β-cells. This review is an update on the recent progress in understanding the EMT process of β-cells and how the investigations have helped to resolve the mystery of the existence of EMT in pancreatic β-cells.