Glycerophospholipids and energy remodeling orchestrate metabolic reprogramming in liver fibrosis

Abstract

Liver fibrosis involves extensive metabolic remodeling, but the coordinated changes in proteins, metabolites and cell-type-specific gene expression signatures remain incompletely defined. This study aimed to comprehensively characterize the molecular and cellular metabolic alterations in liver fibrosis and identify potential metabolic targets for antifibrotic therapy. A CCl 4 -induced murine hepatic fibrosis model was established and validated by histology and serum markers. Integrated proteomics, metabolomics, and single-cell transcriptomics were performed to profile molecular and metabolic changes. Pathway enrichment (KEGG, GO, MBROLE) and network analyses, including Ingenuity Pathway Analysis (IPA), were conducted. Functional validation in hepatic stellate cells (HSCs) included western blot, qPCR, immunofluorescence, and Seahorse assays. Public datasets from metabolic-associated steatohepatitis (MASH/MASLD) patients were analyzed for translational relevance. Integrated multi-omics analysis identified coordinated disorders of arachidonic acid, retinol, linoleic acid, arginine-proline and butanoate metabolism in fibrotic livers. IPA network analysis highlighted PPARα and ERK1/2 as hub regulators, and pharmacological intervention confirmed their direct participation in HSCs activation. Liver fibrosis was characterized by widespread suppression of hepatocyte cytochrome P450 enzymes, disrupted arachidonic acid and retinoid metabolism, and accumulation of glycerophospholipids including phosphatidylethanolamine (PE). Although total PE levels rose in fibrotic liver tissue, exogenous POPE significantly inhibited HSCs activation. Mechanistically, POPE suppressed the MAPK pathway, upregulated PPARα, and restored excessive mitochondrial respiration and glycolysis in activated HSCs. Cell-type-resolved profiling showed that extracellular matrix genes were mainly expressed in HSCs, adhesion and cytoskeletal genes in macrophages, and downregulated cytochrome P450 genes in hepatocytes. These metabolic molecular alterations were consistent with transcriptomic trends in human liver samples with advanced fibrosis. Liver fibrosis is characterized by coordinated, cell-type-dependent remodeling of lipid and energy metabolism. Hepatocyte-associated cytochrome P450 suppression, altered HSC bioenergetics and dysregulated glycerophospholipid metabolism collectively contribute to the fibrotic metabolic landscape. POPE was associated with reduced HSC activation and normalization of MAPK, PPARα and bioenergetic responses, identifying defined phosphatidylethanolamine species as potential modulators of HSC state. Further mechanistic and in vivo studies are required to determine the causal and therapeutic relevance of these findings.