P7C3 alleviates hepatic fibrosis via targeting eIF4A1-mediated protein translation and autophagy in hepatic stellate cells

Abstract

P7C3, an aminopropyl carbazole compound with established neuroprotective properties and therapeutic potential in neurodegenerative disorders, has demonstrated broad pharmacological activity across multiple pathologies. However, the effect of P7C3 on hepatic fibrosis remains unexplored. This research applied in vitro and in vivo systems to evaluate P7C3’s antifibrotic efficacy. The findings demonstrated that P7C3 notably inhibited the proliferation of LX-2 cells and activated primary hepatic stellate cells (HSCs), while also reducing levels of the fibrotic markers collagen type alpha 1 (COL1A1) and fibronectin (FN). Eukaryotic initiation factor 4A1 (eIF4A1) was identified as a direct target of P7C3 through the integration of cellular thermal shift assay (CETSA) coupled with mass spectrometry and human protein microarray data, and subsequently validated using CETSA, drug affinity responsive target stability, and molecular docking analysis. eIF4A1 expression was higher in activated primary HSCs than in quiescent cells. P7C3 treatment markedly inhibited eIF4A1 levels in LX-2 cells and activated primary HSCs. eIF4A1 knockdown downregulated the expression of COL1A1 and FN, whereas its overexpression effectively reversed this suppression. Mechanistically, P7C3 impaired global protein synthesis in hepatic stellate cells, including c-Myc, consistent with the outcomes observed following eIF4A1 silencing. Both eIF4A1 knockdown and P7C3 treatment significantly downregulated ULK1, induced accumulation of autophagic substrate p62, and increased LC3B-II/LC3B-I ratio, indicating potent disruption of autophagic flux via eIF4A1 targeting. Histopathological assessment of the liver tissues revealed that P7C3 significantly attenuated collagen deposition and architectural distortion in fibrotic mice. Concomitant improvements were observed in the hepatic function biomarkers, including serum ALT and AST levels, as well as in fibrotic markers (hydroxyproline content). Collectively, these findings delineated eIF4A1 as the primary target through which P7C3 alleviates hepatic fibrosis by suppressing protein translation and autophagic flux, providing mechanistic validation for advancing it as a promising antifibrotic agent.