Evaluation of the effect of HCV Core protein on the epithelial-mesenchymal transition (EMT) process in non-tumorigenic immortalized hepatocytes

Introduction and Objectives

The HCV Core protein is involved in metabolic remodeling and, energy reprogramming through enzymatic changes and redistribution of energy resources, promoting epithelial-mesenchymal transition (EMT) and liver disease. This study addressed the metabolic changes involved in EMT by evaluating the expression of Vimentin and E-cadherin in a non-cancerous cell model.

Materials and Patients

An expression plasmid for the HCV Core protein genotype 1b (p-Core) was designed. Transient transfection was performed in the THLE-2 cell line, characterized by a morphology similar to non-tumorigenic human hepatocytes and the expression of differentiated hepatocyte markers, making it ideal for metabolic assays due to its ability to express and regulate proteins involved in metabolism more effectively than primary hepatocyte cultures. For the transfection, p-Core concentrations of 0.5 - 2.0 µg were used, and the cells were cultured for 72 hours. Subsequently, total proteins were extracted and quantified using PKR buffer. The expression levels of Core, Vimentin, and E-cadherin proteins were evaluated by Western Blot, using 40 µg of protein. The relative expression of the proteins was calculated in relation to the endogenous expression of GAPDH using ImageJ software, and the analysis was performed in triplicate.

Results

The expression of the viral Core protein (21 kDa) was detected in THLE-2 cells transfected with the p-Core plasmid at 72 hours. It was observed that the expression of the E-cadherin protein (120 kDa) decreased by 80% (in cells transfected with 0.5 µg) and by 25% in cells transfected with 2.0 µg of p-Core. Lastly, an increase in the expression levels of the Vimentin protein (57 kDa) was observed in relation to the concentration of p-Core, doubling with 0.5 µg and increasing sixfold with 2.0 µg of p-Core.

Conclusions

The expression of the viral Core protein modulates the translational expression levels of E-cadherin and Vimentin in THLE-2 cells, suggesting its possible involvement in cell adhesion, mobility, and metabolism by HCV. However, detailed studies of the implicated metabolic pathways are required to establish the activation pathways involved.