Multi-omics analysis of dynamic cellular and transcriptional characteristics in pig liver across physiological and developmental states

The liver undergoes profound metabolic adaptations during development, pregnancy, and castration, yet the underlying cellular and transcriptional dynamics remain poorly understood. Here, we performed single-nucleus RNA-seq on livers of Chenghua sows across developmental (youth, D30; adulthood, Y1) and physiological (late-pregnancy at Y1, PY1; neonatal castration, CY1) states, integrated with spatial transcriptomics and targeted metabolomics for validation. From youth to adulthood, hepatocytes shifted from proliferation to enhanced fatty acid metabolism, evidenced by FASN+/LIPG+ subtype (HepIII) and elevated levels of these metabolites NADP+, NADPH, and NAD+ in Y1. Pseudo-time analysis revealed a functional progression from cell cycle regulation to catabolic metabolism and immune regulation. Pregnancy and castration induced distinct hepatocyte remodeling. PY1 hepatocytes were enriched in lipid catabolism-associated subtypes (Hep1, ABHD5+; Hep3, AIG1+, AR+) with ATF6/TCF7L2 activation promoting fatty acid oxidation, while CY1 hepatocytes were characterized by ribosomal protein-enriched subtypes (Hep5, RPSA+, RPL10+) and BACH1 with enhanced glycolysis and elevated NADP+, suggesting heightened fatty acid metabolism. Beyond hepatocyte-intrinsic changes, pregnancy triggered a marked increase in cell-cell communication, with PY1-specific ligand-receptor pairs (e.g., ANGPTL family, WNT signaling) connecting hepatocytes to non-parenchymal cells, while immune cell subsets (T and NK cells) exhibited state-dependent compositions. Spatial transcriptomics proved hepatocyte-NK cell co-localization in specific niches. Cross-species analysis revealed both conserved liver cell types and species-specific metabolic gene expression profiles across adult pigs, humans, and mice. This work delineates the cellular and transcriptional dynamics of liver homeostasis, supports the pig model for human hepatic research, and provides a valuable multi-omics resource.