Lineage tracing demonstrates no evidence of cholangiocyte epithelial-to-mesenchymal transition in murine models of hepatic fibrosis

Authors

  • Andrew S. Chu,

    1. Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA
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  • Rosalyn Diaz,

    1. Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA
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  • Jia-Ji Hui,

    1. Division of Gastroenterology, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA
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  • Kilangsungla Yanger,

    1. Division of Gastroenterology, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA
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  • Yiwei Zong,

    1. Division of Gastroenterology, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA
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  • Gianfranco Alpini,

    1. Digestive Disease Research Center, Scott & White; Department of Medicine, Scott & White and Texas A&M HSC COM, Central Texas Veterans HCS, Temple, Texas
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  • Ben Z. Stanger,

    1. Division of Gastroenterology, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA
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  • Rebecca G. Wells

    Corresponding author
    1. Division of Gastroenterology, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA
    2. Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA
    • Clinical Research Building, Room 664, Department of Medicine (Gastroenterology), University of Pennsylvania School of Medicine, 415 Curie Boulevard, Philadelphia, PA 19104
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    • fax: (215) 573-2024


  • Potential conflict of interest: Nothing to report.

  • Supported by National Institutes of Health R01 grant DK-058123 (to R.G.W.), R01 grant DK-083355 (to B.Z.S.), and by a grant from the Fred and Suzanne Biesecker Pediatric Liver Center (to R.G.W.). A.C. is a Fellow of the Pediatric Scientist Development Program and is supported by award K12-HD000850 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, by a Childhood Liver Disease Research and Education Network training grant, and by the American Liver Foundation Alexander M. White, III Postdoctoral Research Fellowship Award. R.D. was supported by the National Institutes of Health institutional training grant T32 DK07066.

Abstract

Whether or not cholangiocytes or their hepatic progenitors undergo an epithelial-to-mesenchymal transition (EMT) to become matrix-producing myofibroblasts during biliary fibrosis is a significant ongoing controversy. To assess whether EMT is active during biliary fibrosis, we used Alfp-Cre × Rosa26-YFP mice, in which the epithelial cells of the liver (hepatocytes, cholangiocytes, and their bipotential progenitors) are heritably labeled at high efficiency with yellow fluorescent protein (YFP). Primary cholangiocytes isolated from our reporter strain were able to undergo EMT in vitro when treated with transforming growth factor-β1 alone or in combination with tumor necrosis factor-α, as indicated by adoption of fibroblastoid morphology, intracellular relocalization of E-cadherin, and expression of α-smooth muscle actin (α-SMA). To determine whether EMT occurs in vivo, we induced liver fibrosis in Alfp-Cre × Rosa26-YFP mice using the bile duct ligation (BDL) (2, 4, and 8 weeks), carbon tetrachloride (CCl4) (3 weeks), and 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC; 2 and 3 weeks) models. In no case did we find evidence of colocalization of YFP with the mesenchymal markers S100A4, vimentin, α-SMA, or procollagen 1α2, although these proteins were abundant in the peribiliary regions. Conclusion: Hepatocytes and cholangiocytes do not undergo EMT in murine models of hepatic fibrosis. (Hepatology 2011;)

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