PT - JOURNAL ARTICLE AU - Hui, Hongxiang AU - Wright, Chris AU - Perfetti, Riccardo TI - Glucagon-Like Peptide 1 Induces Differentiation of Islet Duodenal Homeobox-1–Positive Pancreatic Ductal Cells Into Insulin-Secreting Cells AID - 10.2337/diabetes.50.4.785 DP - 2001 Apr 01 TA - Diabetes PG - 785--796 VI - 50 IP - 4 4099 - http://diabetes.diabetesjournals.org/content/50/4/785.short 4100 - http://diabetes.diabetesjournals.org/content/50/4/785.full SO - Diabetes2001 Apr 01; 50 AB - Glucagon-like peptide-1 (GLP-1) is an incretin hormone capable of restoring normal glucose tolerance in aging glucose-intolerant Wistar rats. Whether the antidiabetic properties of GLP-1 are exclusively due to its insulin secretory activity remains to be determined. A GLP-1–dependent differentiation of pancreatic precursor cells into mature β-cells has recently been proposed. The aim of this study was to investigate whether pancreatic ductal epithelial cells could be differentiated into insulin-secreting cells by exposing them to GLP-1. Rat (ARIP) and human (PANC-1) cell lines, both derived from the pancreatic ductal epithelium, were used to test this hypothesis. A major difference distinguishes these two cell lines: whereas ARIP cells spontaneously express the β-cell differentiation factor islet duodenal homeobox-1 (IDX-1), PANC-1 cells are characteristically IDX-1 negative. GLP-1 induced the differentiation of ARIP cells into insulin-synthesizing cells, although it did not affect the phenotype of PANC-1 cells, as determined by fluorescence-activated cell sorting (FACS) analysis. Differentiation of ARIP cells by exposure to human GLP-1 occurs in a time- and dose-dependent manner, and this is associated with an increase in IDX-1 and insulin mRNA levels. Secretion of insulin was also induced in a parallel manner, and it was regulated by the concentration of glucose in the culture medium. Interestingly, PANC-1 cells, when stably transfected with human IDX-1, gained responsiveness to GLP-1 and were able to differentiate into β-cells, as determined by FACS analysis, insulin gene expression, intracellular insulin content, and insulin accumulation in the culture medium. Finally, we demonstrated that the receptor for GLP-1 is constitutively expressed by ARIP and PANC-1 cells and that the mRNA level for this transcript was increased by cellular transfection with human IDX-1. In summary, our study provides evidence that GLP-1 is a differentiation factor for pancreatic ductal cells and that its effect requires the expression of IDX-1.