Skip to main content
. 2021 May 20;11:672490. doi: 10.3389/fonc.2021.672490

Figure 2.

Figure 2

Schematic diagram of cell apoptosis. Once the extracellular cytokines bond to relative death receptors (DRs), DRs recruit FADD intracellularly, this complex initiates the cascade of apoptosis. In some stress conditions, mitochondrial permeability transition will increase, afterwards, Cyto C will be released. With Apaf-1, Cyto C will start the activation cascade from Pro-Caspase 9. In these two ways, caspase 3 is activated finally and exerts the apoptosis process with various mechanisms including the DNA fragmentation in the nucleus. The extrinsic pathway can modulate the intrinsic pathway by the tBid, ASK, and JNK. ASK, apoptosis signal-regulating kinase; Apaf-1, apoptotic protease activating factor-1; CAD, caspase-activated deoxyribonuclease; Cyto C; cytochrome C; Daxx, death domain associated protein; DR, death receptor; FAAD, Fas-associated death domain protein; ICAD, inhibitor of caspase-activated deoxyribonuclease; JNK, c-Jun N-terminal kinase; tBid, truncated Bid; ROS, reactive oxygen species; TNF, tumor necrosis factor; TNFR1, tumor necrosis factor receptor 1; TRADD, Tumor necrosis factor receptor type 1-associated death domain protein. TRAIL, tumor necrosis factor related apoptosis inducing ligand; ┤, Inhibition; →, Promotion.