Praziquantel targeting ESR1 to alleviate liver fibrosis: a comprehensive network analysis insight

Praziquantel is a widely used anthelmintic drug that has demonstrated anti-fibrotic effects in the liver. However, the mechanisms underlying its attenuation of liver fibrosis remain poorly understood. Potential targets of praziquantel associated with liver fibrosis were retrieved from public databases. A protein-protein interaction network was constructed using STRING and Cytoscape to identify hub genes. Mendelian randomization and colocalization analyses were applied to infer causal relationships. Molecular docking and dynamics simulations assessed the binding stability between praziquantel and its predicted target. Single-cell RNA sequencing data were analyzed with Seurat, and virtual knockout simulations were performed using scTenifoldKnk to dissect the functional role of the target genes in hepatic stellate cells (HSCs). Finally, in vitro loss-of-function assays were conducted in LX-2 cells to validate the regulatory function of ESR1 in mediating the anti-fibrotic effects of praziquantel. We identified 137 overlapping target genes. Enrichment analyses indicated that praziquantel exerts its effects via pathways involving xenobiotic metabolism and neuroactive ligand-receptor interactions. Network analysis identified six core hub genes: EGFR, ALB, TP53, PTGS2, ESR1, and CYP3A4. Mendelian randomization supported a protective causal role of ESR1 against liver fibrosis, with colocalization nominating rs3020404 as a potential functional variant underlying this association. Molecular modeling confirmed stable binding of praziquantel to ESR1. Single-cell transcriptomics revealed broad expression of ESR1 across liver cell types, with significantly higher levels in quiescent and cytokine-producing HSCs (cyHSCs) compared to activated myofibroblastic HSCs (myHSCs). Virtual knockout of ESR1 in HSCs disrupted a gene regulatory network, with prominent alterations in RXFP1, EGFLAM and mitochondrial components (MT-CO1, MT-CO2, MT-ND4L). Pathway analysis of these perturbed genes showed significant enrichment in oxidative phosphorylation and immune signaling pathways (T cell receptor signaling). In vitro ESR1 silencing experiments in LX-2 cells confirmed the functional requirement of ESR1 in mediating praziquantel’s anti-fibrotic effects. This integrative study identifies ESR1 as a genetically supported and druggable target of praziquantel in liver fibrosis. We propose a mechanism whereby ESR1, upon activation by praziquantel, orchestrates a protective network that maintains mitochondrial metabolic homeostasis and modulates immunoregulatory signaling in HSCs, thereby inhibiting their fibrogenic activation. Our findings provide a mechanistic rationale for repurposing praziquantel and highlight ESR1 modulation as a promising therapeutic strategy.