Chronic liver injury is characterized by sustained activation of transforming growth factor-β (TGF-β) signaling within the fibrotic microenvironment, yet the contribution of TGF-β-associated metabolic remodeling to hepatic stellate cell (HSC) activation remains incompletely understood. Here, we investigated whether TGF-β signaling is associated with lipid metabolic remodeling in HSCs and whether pirfenidone (PFD) interferes with this process. We found that TGF-β1 was spatially associated with lipid accumulation in fibrotic liver tissue and that TGF-β1/2 promoted HSC proliferation. In vitro, TGF-β1/2 coordinately upregulated sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FASN), accompanied by increased intracellular lipid accumulation and enhanced oleic acid (OA)-associated lipid responses. Low-dose OA further activated AKT/ERK/p70 S6K signaling in HSCs, whereas PFD attenuated these signaling events. In parallel, PFD suppressed TGF-β-associated lipid accumulation in vitro, reduced SREBP1/FASN expression in activated HSC-rich regions in vivo, and alleviated CCl4-induced liver fibrosis. Together, these findings support a model in which TGF-β-associated lipogenic remodeling contributes to HSC activation and suggest that interference with this metabolic state may represent one component of the antifibrotic action of pirfenidone.
Lan et al. (Thu,) studied this question.