摘要：

Serine proteinases are a family of mammalian enzymes with a serine group at their active site. They include the leukocyte serine proteinases, neutrophil elastase, cathespin G, proteinase-3, plasminogen activators, granzymes, chymases, tryptases, and digestive enzymes such as trypsin. Leukocyte serine proteinases are generally synthesized by their bone marrow precursors, stored in intracellular granules, and released from cells when they are activated. Serine proteinases cleave various proteins, such as extracellular matrix proteins, coagulation and complement proteins, cytokines, and cell-surface receptors. They also activate latent matrix metalloproteinases (MMPs) and inactivate tissue inhibitors of MMPs. Serine proteinases kill bacteria and fungi, and they induce platelet activation, goblet cell secretion, and synthesis of cytokines by epithelial cells and phagocytes. Granzymes of cytotoxic lymphocytes kill virally infected cells and tumor cells. The activity of serine proteinases is controlled by serine proteinase inhibitors present in extracellular fluids. Serine proteinases likely play diverse roles in physiologic processes such as tissue repair; in regulating inflammation, coagulation, fibrinolysis, and complement activation; and in host defense. However, when their activity is excessive or inadequately controlled, they may play pathogenetic roles in acute and chronic lung diseases, including chronic obstructive pulmonary disease, cystic fibrosis, acute lung injury, and pulmonary fibrosis.

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