The CFP macromolecule attenuates senescent liver sinusoidal endothelial cell-driven activation of hepatic stellate cells.

Hepatic fibrosis is an independent risk factor for all-cause mortality and liver-related events in patients with metabolic-associated steatohepatitis (MASH). Metabolically induced cellular senescence is a key mechanism driving liver fibrosis, but the underlying mechanism remains incompletely characterized. In this study, an integrated analysis of clinical MASH-fibrosis progression data (GSE135251) and single-cell senescence profiles (SAUL-SEN-MAYO) was performed to identify senescence-associated biomarkers using weighted gene coexpression network analysis (WGCNA) and machine learning methods. A 30-week AMLN diet-induced MASH-fibrosis model in C57BL/6J mice as well as liver sinu soidal endothelial cells (LSECs) with mitomycin C (MMC) and palmitic acid (PA)-induced senescence were used for experimental validation. Gene expression was quantified by quantitative real-time PCR, and protein levels were assessed via Western blotting (WB), immunofluorescence (IF), and ELISA. Liver fibrosis was evaluated with Sirius red and Masson's trichrome staining, and cellular senescence was assessed using β-galactosidase staining. In this study, CFP (encoding properdin), a macromolecular regulatory protein, was identified as a senescence marker that is highly expressed in LSECs and is downregulated in a stage-dependent manner during MASH-fibrosis. Studies in the MASH-fibrosis group demonstrated reduced CFP expression in LSECs, accompanied by decreased colocalization with the LSEC marker LYVE1. In vitro, senescent LSECs promoted the release of TGF-β1, which subsequently activated LX-2 cell proliferation and the development of a fibrotic phenotype. CFP knockdown (si-CFP) further exacerbated senescence and increased TGF-β1 secretion, whereas CFP overexpression (CFP-OE) effectively alleviated these effects.