Multiple activators for pancreatic stellate cells. Adjacent acinar cells as well as neutrophils, macrophages and platelets stimulate pancreatic stellate cells (PSCs) in a paracrine manner involving growth factors, cytokines and reactive oxygen species (ROS). Bacterial endotoxin lipopolysaccharide (LPS) acts on PSCs. Once activated there is autocrine stimulation perpetuated by transforming growth factor β (TGFβ), tumor necrosis factor α (TNFα) and interleukin 6 (IL-6). They further express extracellular matrix components such as collagens I, III and fibronectin, and matrix metalloproteinases as well as their inhibitors.