The role of osteopontin in liver fibrosis

Osteopontin (OPN) is a cytokine and matrix molecule that is upregulated in human and mouse models of chronic liver injury and directly promotes liver fibrogenesis by activating hepatic stellate cells (HSC) and liver progenitors (LPC). OPN is secreted by multiple cell types including HSC, LPC, as well as recruited immune cells such as natural killer T (NKT) cells, which amplify the fibrogenic response. In vivo, OPN neutralization abrogates the LPC response, inhibits HSC activation, and reduces liver fibrosis, thus demonstrating that targeting OPN is a potentially attractive anti-fibrotic strategy.