Changes in gene expression of kringle domain-containing proteins in murine brains and neuroblastoma cells infected by prions.

Prion protein (PrP) interacts with some kringle domain-containing proteins. Kringle domains serve as binding domains in the interaction with PrP. The structural conservation among kringle domains leads to the hypothesis that any protein containing these domains can interact with PrP and be involved in prion pathogenesis. Because prion pathogenesis occurs in the brain, kringle domain-containing proteins should be available in the same tissue if they are relevant to prion pathogenesis. However, gene expression of these proteins in brains infected by prions has not been examined. Here, we showed that plasminogen (plg), urokinase type plasminogen activator (upa), tissue type plasminogen activator (tpa), prothrombin (prothr), and hepatocyte growth factor (hgf) genes were expressed in murine brains and neuroblastoma cells. The changes in upa, prothr, and hgf gene expression correlated with prion disease, but those in plg and tpa gene expression did not. Our data suggest association of gene expression of kringle domain-containing proteins in brains with prion disease.