Inflammatory Cytokine TNFα Promotes the Long-Term Expansion of Primary Hepatocytes in 3D Culture

The study demonstrated that the inflammatory cytokine TNFα was crucial for the long-term expansion of primary hepatocytes in 3D culture, which traditionally have been difficult to maintain in vitro. TNFα facilitated hepatocyte colony formation and maintenance, with cultures lasting up to 8 months. The expansion was mediated through NF-κB signaling, and TNFα's role could not be replaced by IL-6. The cultured hepatocytes retained functional properties and could engraft into the livers of Fah-deficient mice, achieving significant liver reconstitution. This research suggested that TNFα could mimic in vivo liver regeneration processes, highlighting its potential for expanding primary cell types in culture for regenerative medicine applications.