In vitro functional formation of liver sinusoidal endothelial cells in 3D culture system.

Liver sinusoidal endothelial cells (LSECs) are highly specialized endothelial cells that form the barrier between the blood and hepatocytes and hepatic stellate cells (HSCs). LSECs lack a basement membrane and are fenestrated, allowing macromolecule transport across this barrier. In liver inflammation, LSECs dedifferentiate (also called sinusoidal capillarization), form a basement membrane and lose fenestrae, which further promotes fibrosis. During development, LSECs play a role in hepatocyte differentiation and maturation. Furthermore LSECs have the ability to clear hepatitis B virus (HBV), hepatitis C virus (HCV), Ebola viruses, adenoviruses, HIV, and coronaviruses via the CD209 and CD209L pattern recognition receptor. Considering the role of LSECs and their crosstalk with other (non-)parenchymal liver cell types in both homeostatic and pathological conditions, it is crucial to include LSECs in liver co-culture models. However, primary LSECs are known to lose their characteristics such as fenestrae and endocytic capacity within 1-2 days of in vitro culture. Furthermore, the limited availability of human primary LSECs is a major obstacle for progressing LSEC research. In this project we aim to use transcription factor (TF) guided differentiation and a 3D in vitro LSEC model derived from human pluripotent stem cells (hiPSCs) in order to obtain better liver in vitro models.