Zhang Lili, Theise Neil, Chua Michael, Reid Lola M
Department of Cell and Molecular Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
Hepatology. 2008 Nov;48(5):1598-607. doi: 10.1002/hep.22516.
Human livers contain two pluripotent progenitors: hepatic stem cells and hepatoblasts. The hepatic stem cells uniquely express the combination of epithelial cell adhesion molecule (EpCAM), neural cell adhesion molecule (NCAM), cytokeratin (CK) 19, albumin +/-, and are negative for alpha-fetoprotein (AFP). They are precursors to hepatoblasts, which differ from hepatic stem cells in size, morphology, and in expressing the combination of EpCAM, intercellular cell adhesion molecule (ICAM-1), CK19, albumin++, and AFP++. The hepatic stem cells are located in vivo in stem cell niches: the ductal plates in fetal and neonatal livers and canals of Hering in pediatric and adult livers. The hepatoblasts are contiguous to the niches, decline in numbers with age, wax and wane in numbers with injury responses, and are proposed to be the liver's transit-amplifying cells. In adult livers, intermediates between hepatic stem cells and hepatoblasts and between hepatoblasts and adult parenchyma are observed. Amplification of one or both pluripotent cell subpopulations can occur in diseases; for example, hepatic stem cell amplification occurs in mild forms of liver failure, and hepatoblast amplification occurs in forms of cirrhosis. Liver is, therefore, similar to other tissues in that regenerative processes in postnatal tissues parallel those occurring in development and involve populations of stem cells and progenitor cells that can be identified by anatomic, antigenic, and biochemical profiles.
肝干细胞和肝母细胞。肝干细胞独特地表达上皮细胞粘附分子（EpCAM）、神经细胞粘附分子（NCAM）、细胞角蛋白（CK）19、白蛋白+/- 的组合，且甲胎蛋白（AFP）呈阴性。它们是肝母细胞的前体，肝母细胞在大小、形态以及表达EpCAM、细胞间粘附分子（ICAM - 1）、CK19、白蛋白++ 和AFP++ 的组合方面与肝干细胞不同。肝干细胞在体内定位于干细胞龛：胎儿和新生儿肝脏中的胆管板以及儿童和成人肝脏中的赫林管。肝母细胞与这些龛相邻，数量随年龄减少，数量随损伤反应而增减，并且被认为是肝脏的过渡增殖细胞。在成人肝脏中，可观察到肝干细胞与肝母细胞之间以及肝母细胞与成人实质之间的中间细胞。在疾病中，一个或两个多能细胞亚群可能会扩增；例如，肝干细胞扩增发生在轻度肝功能衰竭中，而肝母细胞扩增发生在肝硬化形式中。因此，肝脏与其他组织类似，因为出生后组织中的再生过程与发育过程中发生的过程相似，并且涉及可通过解剖学、抗原性和生化特征识别的干细胞和祖细胞群体。
