Intrinsic and extrinsic regulation of mammalian hematopoiesis in the fetal liver

Histol Histopathol. 2014 Sep;29(9):1077-82. doi: 10.14670/HH-29.1077. Epub 2014 Feb 14.

Abstract

The fetal liver (FL) is an important structure in expansion and differentiation of hematopoietic stem cells (HSC), but despite this little is known about the exact mechanisms in which FL hematopoiesis takes place. Primitive hematopoiesis gives way to definitive hematopoiesis at 12.5 dpc in mice and the process is regulated by a number of intrinsic and extrinsic factors. Intrinsic regulations are intracellular processes that have been reported to be important in the initiation of definitive hematopoiesis. Several structures are involved with extrinsic regulations of hematopoiesis within the FL, including hepatoblasts and liver sinusoidal endothelial cells (LSEC). Hepatoblasts and endothelial cells comprise separate niches involved in the extrinsic regulation of hematopoiesis. Studies have shown that co-cultures with fetal liver stromal cells can promote the expansion of erythroid cells, although the way in which stromal cells do this is still unknown. Understanding the mechanisms in which hematopoiesis is regulated in the FL could lead to the production of novel therapies involving the safe and reliable transplantation of HSCs to patients with blood and bone marrow complications. This review aims to summarize the current state of knowledge about the regulation of hematopoiesis specifically within the FL.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Fetus / physiology*
  • Hematopoiesis / physiology*
  • Hematopoietic Stem Cells / physiology*
  • Humans
  • Liver / embryology*
  • Liver / physiology*