Hedgehog Activity, Epithelial-Mesenchymal Transitions, and Biliary Dysmorphogenesis in Biliary Atresia
Hedgehog Activity, Epithelial-Mesenchymal Transitions, and Biliary Dysmorphogenesis in Biliary Atresia
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DOI：
10.1002/hep.24156
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发表时间：
2011-04-01
期刊：
影响因子：
13.5
通讯作者：
Whitington, Peter F.
中科院分区：
文献类型：
--
作者：
Omenetti, Alessia;Bass, Lee M.;Whitington, Peter F.
胆道闭锁（BA）以显着的胆管反应和纤维化的快速发展而著称。 Hedgehog (Hh) 通路的激活促进未成熟上皮细胞群体的扩张，这些细胞共表达间充质标记物并且可能促纤维化。我们检验了这样的假设：在 BA 中，过度的 Hh 激活会阻碍导管形态发生，并通过促进具有间充质表型的未成熟导管细胞的积累来增强纤维发生。通过定量逆转录聚合酶链反应 (QRT-PCR) 和 Hh 配体、靶基因和间充质细胞或导管祖细胞标记物的免疫染色来评估 BA 患者的肝脏和残余肝外导管。研究结果与患有遗传性胆汁淤积性疾病的儿童、年龄匹配的已故捐赠者对照和成人对照进行了比较。从有和没有胆管结扎的成年大鼠中分离的导管细胞与富含 Hh 配体的培养基 6 Hh 中和抗体一起孵育，以确定 Hh 配体对上皮间质转化 (EMT) 标记物表达的直接影响。儿童对照组的肝脏比成人对照组表现出更强的先天 Hh 激活。在患有 BA 的儿童中，肝内和肝外导管细胞均表现出 Hh 配体产生的显着上调和 Hh 靶基因表达的增加。 Hh 产生细胞和 Hh 反应细胞的过度积累也发生在其他婴儿胆汁淤积性疾病中。对 BA 样本的进一步分析表明，具有间充质表型的未成熟导管细胞具有 Hh 反应性。用富含Hh配体的培养基诱导间充质基因处理未成熟的导管细胞；中和 Hh 配体抑制了这一点。结论：BA 的特点是 Hh 通路过度活跃，刺激胆道 EMT，可能导致胆道畸形发生。其他胆汁淤积疾病也表现出类似的激活，表明这是婴儿期胆汁淤积损伤的常见反应。 （肝病学 2011；53：1246-1258）
Biliary atresia (BA) is notable for marked ductular reaction and rapid development of fibrosis. Activation of the Hedgehog (Hh) pathway promotes the expansion of populations of immature epithelial cells that coexpress mesenchymal markers and may be profibrogenic. We examined the hypothesis that in BA excessive Hh activation impedes ductular morphogenesis and enhances fibrogenesis by promoting accumulation of immature ductular cells with a mesenchymal phenotype. Livers and remnant extrahepatic ducts from BA patients were evaluated by quantitative reverse-transcription polymerase chain reaction (QRT-PCR) and immunostaining for Hh ligands, target genes, and markers of mesenchymal cells or ductular progenitors. Findings were compared to children with genetic cholestatic disease, age-matched deceased donor controls, and adult controls. Ductular cells isolated from adult rats with and without bile duct ligation were incubated with Hh ligand-enriched medium 6 Hh-neutralizing antibody to determine direct effects of Hh ligands on epithelial to mesenchymal transition (EMT) marker expression. Livers from pediatric controls showed greater innate Hh activation than adult controls. In children with BA, both intra-and extrahepatic ductular cells demonstrated striking up-regulation of Hh ligand production and increased expression of Hh target genes. Excessive accumulation of Hh-producing cells and Hh-responsive cells also occurred in other infantile cholestatic diseases. Further analysis of the BA samples demonstrated that immature ductular cells with a mesenchymal phenotype were Hh-responsive. Treating immature ductular cells with Hh ligand-enriched medium induced mesenchymal genes; neutralizing Hh ligands inhibited this. Conclusion: BA is characterized by excessive Hh pathway activity, which stimulates biliary EMT and may contribute to biliary dysmorphogenesis. Other cholestatic diseases show similar activation, suggesting that this is a common response to cholestatic injury in infancy. (HEPATOLOGY 2011;53:1246-1258)