Fanni D, Angotzi F, Lai F, Gerosa C, Senes G, Fanos V, Faa G
a Department of Surgical Sciences, Division of Pathology , University of Cagliari , Cagliari , Italy.
b Neonatal Intensive Care Unit, Neonatal Pathology, Puericulture Institute and Neonatal Section , University of Cagliari , Cagliari , Italy.
J Matern Fetal Neonatal Med. 2018 Mar;31(6):701-707. doi: 10.1080/14767058.2017.1297400. Epub 2017 Mar 13.
The liver is a major hematopoietic organ during embryonic and fetal development in humans. Its hematopoietic activity starts during the first weeks of gestation and continues until birth. During this period the liver is colonized by undifferentiated hematopoietic stem cells (HSCs) that gradually differentiate and once mature, enter the circulatory system through the hepatic sinusoids, this process is called hepatic hematopoiesis. The morphology of hepatic hematopoiesis, has been studied in humans through the years, and led to a characterization of all the cell types that make up these phenomena. Studies on murine models also helped to describe the extent of hepatic hematopoiesis at different gestational ages. Using this knowledge, we attempted to describe how hepatic hematopoiesis morphologically evolves as gestation progresses, in human embryos and fetuses. Thus, we observed a total of 32 tissue specimens obtained from the livers of embryos and fetuses at different gestational ages. Basing our observations on the four stages of liver hematopoiesis identified by Sasaki and Sonoda in mice, we also described four consecutive stages of liver hematopoiesis in humans, which resulted to be highly similar to those described in murine models.
在人类胚胎和胎儿发育过程中，肝脏是主要的造血器官。其造血活动在妊娠的最初几周开始，并持续到出生。在此期间，未分化的造血干细胞（HSCs）定植于肝脏，这些细胞逐渐分化，成熟后通过肝血窦进入循环系统，这一过程称为肝脏造血。多年来，人们一直在研究人类肝脏造血的形态，并对构成这些现象的所有细胞类型进行了表征。对小鼠模型的研究也有助于描述不同胎龄时肝脏造血的程度。利用这些知识，我们试图描述在人类胚胎和胎儿中，随着妊娠进展肝脏造血在形态上是如何演变的。因此，我们总共观察了32个取自不同胎龄胚胎和胎儿肝脏的组织标本。基于佐佐木和园田在小鼠中确定的肝脏造血的四个阶段，我们还描述了人类肝脏造血的四个连续阶段，结果发现与小鼠模型中描述的阶段高度相似。
