Hepatic glypican-3 and alpha-smooth muscle actin overexpressions reflect severity of liver fibrosis and predict outcome after successful portoenterostomy in biliary atresia.

BACKGROUND

Glypican-3 plays a vital role in regulating embryonic morphogenesis of the liver. This study aimed to investigate associations of hepatic expressions of glypican-3 and alpha-smooth muscle actin with clinical parameters in biliary atresia.

METHODS

Liver specimens were obtained from 20 biliary atresia infants and 7 non-biliary atresia controls. Relative mRNA expressions of glypican-3, alpha-smooth muscle actin, and signaling molecules of Wnt/β-catenin were measured using real-time polymerase chain reaction. Protein expressions of glypican-3 and alpha-smooth muscle actin were examined using immunohistochemistry. Masson's trichrome staining was conducted to evaluate the stage of liver fibrosis.

RESULTS

Up-regulation of glypican-3 mRNA expression was observed in biliary atresia livers, and its expression was positively associated with alpha-smooth muscle actin, β-catenin, c-Myc, and cyclin D-1. Immunostaining scores of glypican-3 and alpha-smooth muscle actin were significantly increased in biliary atresia livers. Biliary atresia patients with poor outcomes had significantly greater glypican-3 expression than those with good outcomes, consistent with hepatic alpha-smooth muscle actin expression analysis. Hepatic glypican-3 expression was associated with age, albumin, aspartate transaminase, and alkaline phosphatase in biliary atresia patients, while hepatic alpha-smooth muscle actin expression was correlated with alkaline phosphatase in the patients. Moreover, glypican-3 and alpha-smooth muscle actin expressions were positively associated with fibrosis stage in biliary atresia livers. There was a positive relationship between glypican-3 and alpha-smooth muscle actin expression in biliary atresia livers. Combined high expressions of glypican-3 and alpha-smooth muscle actin were associated with poor survival.

CONCLUSION

Hepatic overexpressions of glypican-3 and alpha-smooth muscle actin were associated with hepatic dysfunction and the degree of liver fibrosis in biliary atresia.