Fetal liver development and implications for liver disease pathogenesis

Advances in single-cell technologies and lineage tracing have improved our understanding of liver development. In this Review, Hoodless and colleagues discuss the formation of liver parenchymal and non-parenchymal cell types, and describe emerging parallels between early liver development and the pathogenesis of liver injury. The metabolic, digestive and homeostatic roles of the liver are dependent on proper crosstalk and organization of hepatic cell lineages. These hepatic cell lineages are derived from their respective progenitors early in organogenesis in a spatiotemporally controlled manner, contributing to the liver's specialized and diverse microarchitecture. Advances in genomics, lineage tracing and microscopy have led to seminal discoveries in the past decade that have elucidated liver cell lineage hierarchies. In particular, single-cell genomics has enabled researchers to explore diversity within the liver, especially early in development when the application of bulk genomics was previously constrained due to the organ's small scale, resulting in low cell numbers. These discoveries have substantially advanced our understanding of cell differentiation trajectories, cell fate decisions, cell lineage plasticity and the signalling microenvironment underlying the formation of the liver. In addition, they have provided insights into the pathogenesis of liver disease and cancer, in which developmental processes participate in disease emergence and regeneration. Future work will focus on the translation of this knowledge to optimize in vitro models of liver development and fine-tune regenerative medicine strategies to treat liver disease. In this Review, we discuss the emergence of hepatic parenchymal and non-parenchymal cells, advances that have been made in in vitro modelling of liver development and draw parallels between developmental and pathological processes.

Automated summary

Advancements in single-cell technologies and lineage tracing have enhanced our understanding of liver development. This review explores the formation of different types of liver cells and highlights the similarities between early liver development and the pathogenesis of liver injury. The research has significantly advanced our knowledge of cell differentiation, fate decisions, and the signaling microenvironment in liver development. This understanding also provides insights into liver disease and cancer and offers potential for improving regenerative medicine strategies.