Which are the intrinsic factors involved in apoptosis?
The intrinsic apoptosis pathway begins when an injury occurs within the cell. Intrinsic stresses such as oncogenes, direct DNA damage, hypoxia, and survival factor deprivation, can activate the intrinsic apoptotic pathway.
What triggers extrinsic apoptosis?
The extrinsic pathway that initiates apoptosis is triggered by a death ligand binding to a death receptor, such as TNF-α to TNFR1. The TNFR family is a large family consisting of 29 transmembrane receptor proteins, organized in homotrimers and activated by binding of the respective ligand(s).
What causes necrosis vs apoptosis?
Apoptosis is a natural physiological process while necrosis is a pathological process, caused due to external agents like toxins, trauma, and infections. Apoptosis is involved in controlling the cell number in the body while necrosis is involved in the induction of immune system, defending the body from pathogens.
What are some events external and internal that could trigger apoptosis in a cell?
The intrinsic pathway to apoptosis is triggered by stress or damage to the cell. Types of stress and damage that can lead the cell to apoptosis include damage to its DNA, oxygen deprivation, and other stresses that impair a cell’s ability to function.
What triggers necrosis?
Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death.
How do you induce apoptosis in cell culture?
Chemical induction of apoptosis
- Set up your cells for treatment: inoculate adherent cells into 10 cm2 tissue culture dishes or suspension cells into T75 flasks at a concentration of ~106 cells/mL.
- Add cellular damaging agents at the recommended concentrations to induce apoptosis.
Which cytochrome is involved in the intrinsic pathway of apoptosis?
Among the key proteins in the intermembrane space of mitochondria is cytochrome c, a component of the electron transport chain (ETC). Once cytoplasmic, cytochrome c initiates the intrinsic pathway of apoptosis by binding to the adaptor protein APAF-1 as it triggers its oligomerization (Li et al., 1997).
How are extrinsic and intrinsic pathways activated?
The intrinsic pathway is activated through exposed endothelial collagen, and the extrinsic pathway is activated through tissue factor released by endothelial cells after external damage. This pathway is the longer pathway of secondary hemostasis.
What factors are in the extrinsic pathway?
The extrinsic pathway consists of the transmembrane receptor tissue factor (TF) and plasma factor VII/VIIa (FVII/FVIIa), and the intrinsic pathway consists of plasma FXI, FIX, and FVIII. Under physiological conditions, TF is constitutively expressed by adventitial cells surrounding blood vessels and initiates clotting.
Which of these statements is true of the intrinsic pathway of apoptosis?
D. Cytochrome C is a necessary component for the intrinsic pathway of apoptosis. E. All of the above statements are true.
How do fibroblasts induce apoptosis?
Apoptosis of cultured fibroblasts can be induced by growth factor deprivation, inhibition of protein kinases, or alteration of ECM-fibroblast interactions (5, 6, 7, 8).
Is cytochrome c involved in extrinsic apoptosis?
Cytochrome c is required for TNFα-induced apoptosis This observation is consistent with the requirement of cytochrome c for the intrinsic but not the extrinsic pathway of apoptosis, and predicted that silencing cytochrome c should not affect apoptosis induced by TNFα in our experimental system.
How does the mitochondria initiate apoptosis?
Mitochondria play key roles in activating apoptosis in mammalian cells. Bcl-2 family members regulate the release of proteins from the space between the mitochondrial inner and outer membrane that, once in the cytosol, activate caspase proteases that dismantle cells and signal efficient phagocytosis of cell corpses.
How do intrinsic and extrinsic pathways differ?
The main difference between intrinsic and extrinsic pathways in blood clotting is that intrinsic pathway is activated by a trauma inside the vascular system whereas extrinsic pathway is activated by external trauma.