An update of understanding of the hepatic vascular system and new research strategies

Abstract

Although the portal vessels, liver sinusoids, and central vessels are known to contain microvessels with different structures and functions, their changes and roles in liver fibrogenesis have not been fully understood. Recent studies suggest that in mouse models of liver fibrogenesis, vascular changes can occur at a very early stage, and different liver vessels undergo different changes and play different roles, as shown by a decreased number of portal vessels, increased sinusoid capillarization and increased central vessels. The increase of portal vessels alleviates liver fibrosis, while the increase of central vessels and sinusoid capillarization aggravates liver fibrosis. A full understanding of the regulatory mechanisms of each of these vessels is vital for treatment of liver fibrosis. A combined regulation of different endothelial cell (EC) regulatory signaling pathways for vascular normalization may provide new strategies for liver fibrosis therapy. Further studies of the changes and functions of blood vessels in different liver diseases, liver development and regeneration may bring about important breakthroughs. This review summarizes the changes of 3 hepatic microvessels and their roles in liver fibrogenesis and propose the major directions of future studies in this field.