Laboratory of Gastroenterology, Université Catholique de Louvain, Brussels, Belgium.
Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden.
Am J Pathol. 2019 Aug;189(8):1569-1581. doi: 10.1016/j.ajpath.2019.04.011. Epub 2019 May 18.
Ductular reaction (DR) is observed in virtually all liver diseases in both humans and rodents. Depending on the injury, DR is confined within the periportal area or invades the parenchyma. On severe hepatocellular injury, invasive DR has been proposed to arise for supplying the liver with new hepatocytes. However, experimental data evidenced that DR contribution to hepatocyte repopulation is at the most modest, unless replicative capacity of hepatocytes is abrogated. Herein, we proposed that invasive DR could contribute to operating hepatobiliary junctions on hepatocellular injury. The choline-deficient ethionine-supplemented mouse model of hepatocellular injury and human liver samples were used to evaluate the hepatobiliary junctional role of the invasive form of DR. Choline-deficient ethionine-supplemented-induced DR expanded as biliary epithelium into the lobule and established new junctions with the canaliculi. By contrast, no new ductular-canalicular junctions were observed in mouse models of biliary obstructive injury exhibiting noninvasive DR. Similarly, in humans, an increased number of hepatobiliary junctions were observed in hepatocellular diseases (viral, drug induced, or metabolic) in which DR invaded the lobule but not in biliary diseases (obstruction or cholangitis) in which DR was contained within the portal mesenchyme. In conclusion, our data in rodents and humans support that invasive DR plays a hepatobiliary junctional role to maintain structural continuity between hepatocytes and ducts in disorders affecting hepatocytes.
小管反应 (DR) 在人类和啮齿动物的几乎所有肝脏疾病中都观察到。根据损伤的不同,DR 局限于门脉周围区域或侵犯实质。在严重的肝细胞损伤中,侵袭性 DR 的出现被认为是为肝脏提供新的肝细胞。然而,实验数据表明,DR 对肝细胞再增殖的贡献是最小的,除非肝细胞的复制能力被削弱。在此,我们提出侵袭性 DR 可能有助于在肝细胞损伤时发挥肝胆连接作用。使用胆碱缺乏蛋氨酸补充的肝细胞损伤小鼠模型和人类肝脏样本来评估侵袭性 DR 的肝胆连接作用。胆碱缺乏蛋氨酸补充诱导的 DR 扩展为胆管上皮细胞进入小叶,并与胆小管建立新的连接。相比之下,在表现出非侵袭性 DR 的胆汁淤积性肝损伤的小鼠模型中,没有观察到新的胆小管-胆小管连接。同样,在人类中,在肝细胞疾病(病毒性、药物诱导或代谢性)中观察到更多的肝胆连接,其中 DR 侵犯小叶,但在胆汁淤积性疾病(梗阻或胆管炎)中,DR 局限于门脉间质中,没有观察到新的胆小管-胆小管连接。总之,我们在啮齿动物和人类中的数据支持侵袭性 DR 发挥肝胆连接作用,以维持影响肝细胞的疾病中肝细胞和胆管之间的结构连续性。