Dexamethasone Treatment Induces the Reprogramming of Pancreatic Acinar Cells to Hepatocytes and Ductal Cells

Amani Al-Adsani,Chia-Ning Shen,Katherine L Lawrence,Anil K Rustgi,J Mark Farrant,Daniel Eberhard,Hiroshi Sakaue,Zoë D Burke,David Tosh,Irene Oi Lin Ng

doi:10.1371/journal.pone.0013650

Abstract

BackgroundThe pancreatic exocrine cell line AR42J-B13 can be reprogrammed to hepatocytes following treatment with dexamethasone. The question arises whether dexamethasone also has the capacity to induce ductal cells as well as hepatocytes.Methodology/Principal FindingsAR42J-B13 cells were treated with and without dexamethasone and analyzed for the expression of pancreatic exocrine, hepatocyte and ductal markers. Addition of dexamethasone inhibited pancreatic amylase expression, induced expression of the hepatocyte marker transferrin as well as markers typical of ductal cells: cytokeratin 7 and 19 and the lectin peanut agglutinin. However, the number of ductal cells was low compared to hepatocytes. The proportion of ductal cells was enhanced by culture with dexamethasone and epidermal growth factor (EGF). We established several features of the mechanism underlying the transdifferentiation of pancreatic exocrine cells to ductal cells. Using a CK19 promoter reporter, we show that a proportion of the ductal cells arise from differentiated pancreatic exocrine-like cells. We also examined whether C/EBPβ (a transcription factor important in the conversion of pancreatic cells to hepatocytes) could alter the conversion from acinar cells to a ductal phenotype. Overexpression of an activated form of C/EBPβ in dexamethasone/EGF-treated cells provoked the expression of hepatocyte markers and inhibited the expression of ductal markers. Conversely, ectopic expression of a dominant-negative form of C/EBPβ, liver inhibitory protein, inhibited hepatocyte formation in dexamethasone-treated cultures and enhanced the ductal phenotype.Conclusions/SignificanceThese results indicate that hepatocytes and ductal cells may be induced from pancreatic exocrine AR42J-B13 cells following treatment with dexamethasone. The conversion from pancreatic to hepatocyte or ductal cells is dependent upon the expression of C/EBPβ.

Highlights

Transdifferentiation belongs to the wider class of cell type conversions known as reprogramming [1]
We show that (i) ductal cells are formed in Dex-treated B13 cells, (ii) the number of ductal cells can be increased by treatment with Dex and epidermal growth factor (Dex/EGF) in combination (iii) ductal cells can arise from exocrine cells and (iv) overexpression of CCAAT enhancer binding protein b (C/EBPb), a transcription factor previously shown to mediate hepatocyte transdifferentiation of pancreatic cells, inhibits conversion to a ductal phenotype
We demonstrate that cells resembling a ductal phenotype are induced following treatment of pancreatic B13 cells with Dex

Summary

Introduction

Transdifferentiation belongs to the wider class of cell type conversions known as reprogramming [1]. We previously developed an in vitro model for studying the reprogramming of pancreatic cells to hepatocytes based on the addition of the synthetic glucocorticoid dexamethasone (Dex) to AR42J-B13 (B13) cells [6,7]. AR42J cells may be induced to form insulin-producing b-cells following treatment with hepatocyte growth factor (HGF) and activin [11] suggesting the cells may exhibit a progenitor phenotype. The question arises whether other types of cells (apart from hepatocytes), are induced following Dex treatment of AR42J-B13 cells. The pancreatic exocrine cell line AR42J-B13 can be reprogrammed to hepatocytes following treatment with dexamethasone. The question arises whether dexamethasone has the capacity to induce ductal cells as well as hepatocytes

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Results

Conclusion