image: The central vein (CV) region, driven by the Wnt signaling pathway, and the portal vein (PV) region, driven by the Notch signaling pathway, enable us to construct a biomimetic liver lobule microenvironment model with distinct functional and structural zones using genetic engineering and tissue engineering techniques.
Credit: ©Science China Press
The liver’s intricate metabolic zonation, which dictates distinct hepatocyte functions across periportal and pericentral regions, plays a central role in both physiological homeostasis and pathological processes. However, replicating such spatial organization in vitro has long remained a challenge in liver research and preclinical drug evaluation. A research team from Tsinghua University has developed a breakthrough human liver organoid platform that closely replicates the liver’s region-specific functional architecture, offering new opportunities for disease modeling and drug screening.
The team combined primary human hepatocytes with genetically engineered liver sinusoidal endothelial cells (LSECs) to reconstruct organoids that reflect the liver’s native zonation. By systematically analyzing transcriptomic datasets from both human and rodent models, the researchers identified zone-specific signaling pathways dominated by Wnt/β-catenin activity in the pericentral region and Notch signaling in the periportal region. Immunofluorescence and immunohistochemistry on human liver tissue confirmed these spatial expression patterns, providing a molecular blueprint for engineering distinct endothelial niches.
To translate these findings into a functional model, the team developed two transgenic SK-Hep1 endothelial cell lines overexpressing WNT2 and DLL4, key ligands mediating Wnt and Notch signaling, respectively. Co-culture of these engineered endothelial cells with primary hepatocytes induced region-specific hepatocyte differentiation. Organoids co-cultured with WNT2-expressing cells exhibited enhanced cytochrome P450 enzyme activity, mimicking pericentral metabolic features, while DLL4-expressing cells promoted bile transport and cholangiocyte-like phenotypes representative of periportal zones. The system also supported hepatic progenitor bifurcation into hepatocyte- and cholangiocyte-dominant organoid subtypes, recapitulating developmental lineage decisions driven by microenvironmental cues.
Importantly, the organoid platform demonstrated high sensitivity in pharmacological assays. In acetaminophen-induced injury models, WNT2-co-cultured organoids exhibited enhanced susceptibility to oxidative damage but also showed robust regenerative capacity upon withdrawal of the toxic agent. When exposed to fatty acids, these organoids developed significant steatotic changes, which were responsive to clinically relevant anti-steatotic drugs. Conversely, DLL4-co-cultured organoids effectively modeled cholestatic injury, characterized by impaired bile clearance following drug exposure, a phenotype reversible by known choleretic agents.
Taking this approach further, the team employed 3D bioprinting technology to spatially organize endothelial and parenchymal cells into a biomimetic liver lobule architecture. This engineered lobule exhibited clear metabolic zonation, with region-specific expression of functional markers such as glutamine synthetase and MRP2, alongside enhanced albumin and urea production. Notably, the pericentral-mimicking zones within the printed lobule demonstrated distinct vulnerability to acetaminophen toxicity, mirroring in vivo hepatic injury patterns.
This study represents a significant step forward in liver tissue engineering and functional disease modeling. By integrating gene-engineered endothelial signals with advanced 3D bioprinting, the researchers have created a physiologically relevant platform capable of capturing the spatial complexity of liver function and injury responses. Such systems hold promise not only for improving preclinical drug screening accuracy but also for advancing personalized medicine approaches in hepatology.
Beijing Tsinghua Changgung Hospital Hepatobiliary and Pancreatic Center, established in November 2014, stands as Asia's first physically integrated hepatobiliary and pancreatic medical center. It is designated as a "Demonstration Base for Standardized Diagnosis and Treatment of Primary Liver Cancer in China" and serves as the institutional base for the Precision Hepatobiliary Surgery Academy of the Chinese Research Hospital Association. The Center integrates multiple subspecialties, including Hepatology, Hepato-Pancreato-Biliary Surgery, Liver Transplantation, Comprehensive Hepatobiliary Tumor Therapy, Interventional Therapy for Hepatobiliary Diseases, Pediatric Hepatobiliary Disease Diagnosis and Treatment, and the Hepatic Intensive Care Unit (ICU). Committed to advancing patient care, it delivers systematic diagnosis and full-cycle management for hepatobiliary disorders through precision medicine and multidisciplinary treatment models (MDT).