PAI-1 as a modulator of the EMT-associated signaling pathway during HCV protein expression

Hepatitis C virus (HCV) infection promotes liver fibrosis through mechanisms involving epithelial-mesenchymal transition (EMT). Plasminogen activator inhibitor-1 (PAI-1), encoded by the SERPINE1 gene, is a known modulator of EMT and is upregulated during HCV infection. This study aimed to explore the contribution of PAI-1 silencing to EMT-related biomarker regulation in the context of HCV protein expression.

Huh7 cells were transfected with plasmids encoding HCV Core or NS5A proteins and subjected to SERPINE1 silencing. Some EMT-related biomarkers (TGFβ1, vimentin, E-cadherin) and viral protein levels were assessed by Western blot and nanoluciferase assays. Bioinformatic analysis of RNA-seq public datasets was performed to evaluate SERPINE1 expression in liver fibrosis stages and HCV-infected hepatocytes in vitro.

In vitro assays revealed that PAI-1 silencing is associated with the downregulation of E-cadherin and the upregulation of vimentin and TGFβ1 in both Core- and NS5A-expressing Huh7 cells. Temporal analyses confirmed that PAI-1 silencing is related to vimentin and TGFβ1 overexpression over time. Bioinformatic analysis revealed SERPINE1 expression increased with liver fibrosis severity and was elevated in HCV-infected hepatocytes. It showed strong positive correlations with genes involved in EMT.

Our data indicate that PAI-1 may contribute to the modulation of certain EMT-related biomarkers during HCV protein expression in Huh7 cells. These findings highlight PAI-1 as a possible target for the modulation of EMT and fibrosis progression in chronic HCV infection.