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Background &amp; aims <p>The Wnt/β-catenin signaling pathway is critical for liver homeostasis. We have previously shown that hepatocyte β-catenin plays a pleiotropic role in cholestatic injury. However, the role of cholangiocyte β-catenin signaling during cholestasis remains unclear.</p> Methods <p>Inducible-Osteopontin (OPN)-Cre-β-catenin-floxed C57BL/6 mice were used in two cholestasis models. <i>Mdr2</i> knockout (KO)-β-catenin-floxed:OPN-Cre mice were administered tamoxifen to delete β-catenin from cholangiocytes. Wild-type and cholangiocyte β-catenin KO mice were also administered a 3,5‐diethoxycarbonyl‐1,4‐dihydrocollidine (DDC) diet to induce cholestasis. Serum was collected to evaluate liver enzymes. qRT-PCR and immunohistochemistry/immunofluorescence assays were performed on whole livers to assess injury, vascular remodeling, and hepatocyte reprogramming. Livers were isolated for transmission electron microscopy. Isolated cholangiocytes were analyzed by RNA-seq. Cholangiocytes were treated with β-catenin siRNA and lipopolysaccharide in vitro to determine changes in angiogenic factors and NF-κB activation. Conditioned media from cholangiocytes were used to evaluate endothelial cell proliferation in vitro.</p> Results <p>Mice lacking cholangiocyte β-catenin showed similar levels of hepatobiliary injury compared to controls. We observed more hepatocytes expressing cholangiocyte markers and ductular cells expressing β-catenin in β-catenin KO animals, indicating enhanced hepatocyte reprogramming. Interestingly, cholangiocyte β-catenin KO also had fibrotic hepatic arteries and increased angiogenesis versus controls. Histology and transmission electron microscopy revealed increased basement membrane formation and loss of fenestrations in the sinusoids of β-catenin KO animals. RNA-seq of isolated β-catenin KO cholangiocytes revealed increased expression of angiogenesis pathways that was associated with NF-κB activation. In vitro studies silencing β-catenin in cholangiocytes induced Vegf and Pdgfb expression. Lipopolysaccharide stimulation increased NF-κB nuclear localization in β-catenin-silenced cholangiocytes. Stimulated media from these cells promoted endothelial cell proliferation, recapitulating the angiogenic phenotype found in vivo.</p> Conclusions <p>β-catenin signaling in cholangiocytes is a novel mediator of cell–cell communication, and its loss induces a pro-angiogenic phenotype and supports hepatocyte reprogramming during cholestasis, both of which may prevent accelerated liver injury.</p> Graphical Abstract <p></p>

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Loss of β-catenin in cholangiocytes promotes hepatocyte reprogramming and vascular remodeling during murine cholestasis

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2026年1月10日

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  • Matthew Carson,
  • Jamie Fornsaglio,
  • Ridgeway Case IV,
  • Rithwik Aggarwal,
  • Vik Meadows,
  • Chang Kyung Kim,
  • Laura Molina,
  • Pamela Cornuet,
  • Jia-Jun Liu,
  • Silvia Liu,
  • Kari Nejak-Bowen

摘要

Background & aims

The Wnt/β-catenin signaling pathway is critical for liver homeostasis. We have previously shown that hepatocyte β-catenin plays a pleiotropic role in cholestatic injury. However, the role of cholangiocyte β-catenin signaling during cholestasis remains unclear.

Methods

Inducible-Osteopontin (OPN)-Cre-β-catenin-floxed C57BL/6 mice were used in two cholestasis models. Mdr2 knockout (KO)-β-catenin-floxed:OPN-Cre mice were administered tamoxifen to delete β-catenin from cholangiocytes. Wild-type and cholangiocyte β-catenin KO mice were also administered a 3,5‐diethoxycarbonyl‐1,4‐dihydrocollidine (DDC) diet to induce cholestasis. Serum was collected to evaluate liver enzymes. qRT-PCR and immunohistochemistry/immunofluorescence assays were performed on whole livers to assess injury, vascular remodeling, and hepatocyte reprogramming. Livers were isolated for transmission electron microscopy. Isolated cholangiocytes were analyzed by RNA-seq. Cholangiocytes were treated with β-catenin siRNA and lipopolysaccharide in vitro to determine changes in angiogenic factors and NF-κB activation. Conditioned media from cholangiocytes were used to evaluate endothelial cell proliferation in vitro.

Results

Mice lacking cholangiocyte β-catenin showed similar levels of hepatobiliary injury compared to controls. We observed more hepatocytes expressing cholangiocyte markers and ductular cells expressing β-catenin in β-catenin KO animals, indicating enhanced hepatocyte reprogramming. Interestingly, cholangiocyte β-catenin KO also had fibrotic hepatic arteries and increased angiogenesis versus controls. Histology and transmission electron microscopy revealed increased basement membrane formation and loss of fenestrations in the sinusoids of β-catenin KO animals. RNA-seq of isolated β-catenin KO cholangiocytes revealed increased expression of angiogenesis pathways that was associated with NF-κB activation. In vitro studies silencing β-catenin in cholangiocytes induced Vegf and Pdgfb expression. Lipopolysaccharide stimulation increased NF-κB nuclear localization in β-catenin-silenced cholangiocytes. Stimulated media from these cells promoted endothelial cell proliferation, recapitulating the angiogenic phenotype found in vivo.

Conclusions

β-catenin signaling in cholangiocytes is a novel mediator of cell–cell communication, and its loss induces a pro-angiogenic phenotype and supports hepatocyte reprogramming during cholestasis, both of which may prevent accelerated liver injury.

Graphical Abstract