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

CFP was identified as a senescence-associated biomarker highly expressed in liver sinusoidal endothelial cells (LSECs) that is downregulated in a stage-dependent manner during MASH-fibrosis progression.

• Identification was performed using integrated analysis of clinical MASH-fibrosis progression data (GSE135251) and single-cell senescence profiles (SAUL-SEN-MAYO)
• Weighted gene coexpression network analysis (WGCNA) and machine learning methods were used to identify CFP as the senescence-associated biomarker
• CFP encodes properdin, described as a macromolecular regulatory protein
• Downregulation of CFP occurred in a stage-dependent manner during MASH-fibrosis progression

In the MASH-fibrosis mouse model, reduced CFP expression in LSECs was accompanied by decreased colocalization with the LSEC marker LYVE1.

• A 30-week AMLN diet-induced MASH-fibrosis model in C57BL/6J mice was used for experimental validation
• Colocalization of CFP with the LSEC marker LYVE1 was assessed, and this colocalization was decreased in the MASH-fibrosis group
• Protein levels were assessed via Western blotting, immunofluorescence, and ELISA
• Liver fibrosis was evaluated with Sirius red and Masson's trichrome staining

Senescent LSECs promoted the release of TGF-β1, which subsequently activated LX-2 cell proliferation and development of a fibrotic phenotype.

• LSEC senescence was induced in vitro using mitomycin C (MMC) and palmitic acid (PA)
• Cellular senescence was assessed using β-galactosidase staining
• Senescent LSECs drove activation of LX-2 cells (a hepatic stellate cell line) through TGF-β1 release
• LX-2 cell proliferation and fibrotic phenotype development were observed as downstream consequences of senescent LSEC-derived TGF-β1

CFP knockdown further exacerbated LSEC senescence and increased TGF-β1 secretion.

• CFP knockdown was achieved using siRNA (si-CFP)
• si-CFP treatment resulted in worsened cellular senescence as measured by β-galactosidase staining
• si-CFP treatment led to increased TGF-β1 secretion compared to controls
• Gene expression was quantified by quantitative real-time PCR and protein levels by Western blotting and ELISA

CFP overexpression effectively alleviated LSEC senescence and reduced TGF-β1 secretion.

• CFP overexpression (CFP-OE) was used as the intervention condition in vitro
• CFP-OE effectively alleviated senescence effects in LSECs
• CFP-OE reduced TGF-β1 secretion compared to senescent LSEC controls
• These findings position CFP overexpression as a potential approach to attenuate senescent LSEC-driven hepatic stellate cell activation

Metabolically induced cellular senescence in LSECs was identified as a key mechanism driving liver fibrosis in MASH.

• Hepatic fibrosis is described as an independent risk factor for all-cause mortality and liver-related events in patients with metabolic-associated steatohepatitis (MASH)
• The study used both a 30-week diet-induced mouse model and in vitro senescence induction with MMC and PA to characterize this mechanism
• The senescence-to-fibrosis axis operated through LSEC senescence leading to TGF-β1 release and subsequent hepatic stellate cell activation
• Single-cell senescence profiles (SAUL-SEN-MAYO) were incorporated into the bioinformatic analysis to characterize senescence in specific cell types