Increased Pygo2 expression in liver of patients with hepatitis B virus-related fibrosis

It has been reported that Wnt/β-catenin signalling pathway played a key role in liver fibrosis and that Pygo2 was an important mediator in β-catenin induced pathway. However, the role of Pygo2 in liver fibrogenesis was unknown. Our study was to investigate the expression of Pygo2 and its diagnostic value in patients with HBV-related liver fibrosis.

Hundred and sixty-four patients with HBV infection underwent liver biopsy and liver stiffness measurement (LSM) by transient elastography (Fibroscan(®) ; Echosens). Liver function was tested by routine biochemical examinations. Liver condition was assessed by haematoxylin and eosin (H&E) and Masson's trichrome staining. The expression of Pygo2 in liver tissue was measured by Real-time PCR and immunohistochemistry, respectively, while the serum levels of Pygo2 were detected by ELISA. The relationship between degree of liver fibrosis and Pygo2 expression was assessed by correlation analysis. Receiver operating characteristics (ROC) analysis was used to evaluate diagnostic accuracy of serum Pygo2, LSM and their combination.

The mRNA and protein levels of Pygo2 in HBV-infected patients were all higher than in normal persons (P < 0.05 respectively). Moreover, Pygo2 expression increased along with the progression of liver fibrosis (P < 0.05 respectively). The trend of serum Pygo2 agreed with its expression in liver tissue. The combination of serum Pygo2 and LSM had a significantly higher area under the curve than Pygo2 or LSM alone (P < 0.05 respectively).

This study suggested that Pygo2 was involved in HBV-induced liver fibrogenesis. Pygo2 is a valuable biomarker for the evaluation of fibrosis in HBV-infected patients.