id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-020757-q4ivezyq	Saikumar, Pothana	Apoptosis and Cell Death: Relevance to Lung	2010-05-21		.txt	text/plain	7402	420	39	The extrinsic pathway involves binding of death ligands such as tumor necrosis factor-α (TNF-α), CD95 ligand (Fas ligand), and TNF-related apoptosis-inducing ligand (TRAIL) to their cognate cell surface receptors TNFR1, CD95/Fas, TRAIL-R1, TRAIL-R2, and the DR series of receptors, 29 resulting in the activation of initiator caspase-8 (also known as FADD-homologous ICE/CED-3-like protease or FLICE) and subsequent activation of effector caspase-3 ( Figure 4 .2). In cytotoxic T lymphocyte-induced death, granzyme B, which enters the cell through membrane channels formed by the protein perforin, activates caspases by cleaving them directly or indirectly. Intracellular Pathways: Lack of survival stimuli (withdrawal of growth factor, hypoxia, genotoxic substances, etc.) is thought to generate apoptotic signals through ill-defi ned mechanisms, which lead to translocation of proapoptotic proteins such as Bax to the outer mitochondrial membrane. For example, agents that damage DNA, such as ionizing radiation and certain xenobiotics, lead to activation of p53-mediated mechanisms that commit cells to apoptosis, at least in part through transcriptional upregulation of proapoptotic proteins.	./cache/cord-020757-q4ivezyq.txt	./txt/cord-020757-q4ivezyq.txt