Leukocytes as modulators of stellate cell activation

Activation of stellate cells is central to the process of hepatic fibrogene sis. Stellate cell activation can be influenced by many factors, including cytokines, oxidants, and alterations in the perisinusoidal extracellular ma trix. These factors can be produced by resident liver cells (hepatocytes, K upffer cells, or stellate cells themselves); however, infiltrating leukocyt es may also play an important role. Because liver fibrosis often follows a prolonged period of hepatic inflammation, investigators have begun to study leukocytes as modulators of stellate cell activation. The following data s ummarize recent investigations in this area that focus on neutrophils as we ll as mononuclear cells.