IL-4-mediated Pro-Regenerative Cellular Reprogramming in 3D Liver Culture

Interleukin-4 (IL-4) is a key contributor to liver regeneration but its effects remain poorly understood due to a lack of models that preserve the complex cellular interactions of the liver. Here, we use murine precision-cut liver slices (PCLS), a 3D tissue culture system that maintains both parenchymal and non-parenchymal cells, to investigate the role of IL-4 in hepatic cell reprogramming. Through longitudinal single-cell transcriptomics and protein-level validation, we demonstrate the pro-regenerative potential of IL-4. We performed longitudinal single nucleus RNA sequencing on PCLS from 8-10 week old C57BL/6 mice over 5 days of culture in the presence and absence of IL-4. We assessed intracellular ATP output to demonstrate slice viability. We further performed orthogonal evaluations of the impact of IL-4 treatment via IHC staining to confirm proliferation and cell identity within the slices. We then assessed the impact of IL-4 exposure in slices generated from the diseased livers (hepatonecrosis/fibrosis) of mice treated with thioacetamide. IL-4 induced transcriptional changes, including increased expression of tissue repair associated markers in myeloid cells, expansion of hepatocyte and cholangiocyte progenitors, and inhibition of fibroblast activation. Additionally, IL-4 treatment significantly increased Ki67 protein expression and intracellular ATP production, indicating enhanced proliferation and viability. Notably, IL-4 also improved cellular viability in slices from thioacetamide-treated mice, highlighting its potential pro-regenerative effects in injured liver tissue. Our study highlights the potential of IL-4-driven modulation of the liver microenvironment, paving the way for cytokine-based therapeutic strategies to enhance immune-mediated hepatic regeneration.