In vitro transformation of adult rat hepatic progenitor cells into pancreatic endocrine hormone-producing cells

Abstract

Pancreatic and duodenal homeobox factor 1 (Pdx-1) plays an important role in initiating differentiation toward pancreatic endocrine cells. The transdifferentiation or transformation of hepatocytes into pancreatic endocrine cells could be feasible, due to their similar cellular origins. Our goal in this study was to see if small hepatocytes (SHs) could give rise to pancreatic endocrine cells via exogenous Pdx-1 gene expression. SHs were cultured for 10 days before adenovirus (Adt)-mediated Pdx-1 gene transfection. We performed western blot analysis for pancreatic transcription factors in the nuclei and reverse-transcription polymerase chain reaction (RT-PCR) for the gene expression of pancreatic endocrine hormones. Confocal laser microscanning analysis was used to observe the transformation of SHs. Pancreatic transcription factors such as Pdx-1, Ngn3, NeuroD, Nkx2.2, and Pax6 were induced after Adt-Pdx-1 gene transfection. The mRNA expression of pancreatic endocrine hormones (insulin, glucagon, and somatostatin) was induced after the gene transfection. Pdx-1 was expressed in the nucleus, where the cells were positive for one or more of the hormones and cytokeratin (CK) 8. Some cells were positive for multiple hormones. The insulin level increased while the glucagon level decreased after the glucose loading test, depending on the glucose concentration. SHs are transformed into functional pancreatic endocrine cells after Pdx-1 gene transfection.