A new function for an old enzyme: the role of DNase I in apoptosis.

摘要: Programmed cell death or apoptosis (Greek for the falling of leafs in autumn) is an event by which cells are deliberately eliminated (recently reviewed Ucker 1991, Williams et al. 1992 and Cohen 1993). It occurs during embryogenesis, formation digits from a limb bud, selection immunocompetent B autoreactive T cells, many tissues to provide stable balance cellular mass. The morphologic events differ those necrosis, defined as dying plasma membrane injury. During apoptosis, nuclear chromatin rapidly condenses form crescent-shaped deposits along envelope. nucleus convolutes fragments, while cytoplasmic forms protuberances. These subsequently released forming so-called apoptotic bodies containing highly condensed DNA. whole may disintegrate into large number membrane-sealed immediately phagocytosed neighboring macrophages. Apoptosis affects only single dispersed given tissue there no release contents extracellular space therefore inflammatory reaction induced. In contrast, necrotic usually cells. Due injury, leak ensues.