True about Apoptosis are all except :
High-Yield Explanation
inflammation is present [Ref. Robbins 7th/e p 31, 271 At early stage of apoptosis dying cells secrete soluble factors that recruit phagocytes. Apoptotic cells express phosplzatidylserine in the outer layers of their plasma membrane. Some times thrombospondin is also expressed on the surface of apoptotic bodies. These alterations permit the early recognition of dead cells by the macrophages, resulting in phagocytosis without the release of proinflammatory cellular components. In this way apoptotic response disposes of cells with minimal compromise to the surrounding tissue. The process of phagocytosis of apoptotic cells is so efficient that dead cells disappear without leaving a trace and inflammation is viually absent. Thus apoptosis is fundamentally different from necrosis which is characterized by loss of membrane integrity enzymatic digestion of cells and frequently a host reaction. In case of apoptosis, the cell membrane remains intact. The two most striking features of apoptosis are: 1.1n contrast to necrosis it does not elicit inflammation 2. Considerable apoptosis may occur in tissues before it becomes apparent in histological section (because it occurs very rapidly). Morphological changes in apoptosis 1. Cell shrinkage This is the earliest change. It is due to damage of cytoskeletal proteins that provide structural suppo to the cell. 2. Chromatic Condensation (Pyknosis) This is due to breakdown and clumping of chromatin. This is most characteristic feature of apoptosis 3.Formation of cytoplasimic blebs and apoptotic bodies ---> End stage is characterised by bleb formation. 4. Chromosomal DNA fragmentation It is due to activity of endoneuclease and caspases. 5.Phagocytosis of apoptotic cells and bodies by adjacent macrophages or healthy parenchymal cells. In histological sections apoptotic cell appears as round or oval mass of intensely eosinophilic cytoplasm with dens nucleus chromatin fragments. Note : Cell shrinkage and fragmentation allow the cells to be efficiently phagocytosed without release of proinflammatory cellular component.