Apoptosis is a regulated, generally non-lytic cell-death pathway that removes unwanted, damaged, infected, or abnormal cells through coordinated morphological changes, caspase activation, DNA fragmentation, and membrane remodeling. The intrinsic apoptosis pathway is controlled mainly by mitochondrial outer membrane permeabilization, BCL-2 family proteins, cytochrome c release, apoptosome formation, caspase-9 activation, and downstream executioner caspase-3/7 activation. The extrinsic apoptosis pathway is initiated by death receptors such as Fas, TNFR, and TRAIL receptors, which recruit adaptor proteins and activate caspase-8 before engaging executioner caspases or mitochondrial amplification through BID cleavage. Apoptosis is linked to many phenotypes, including cancer cell killing, tissue homeostasis, immune regulation, neurodegeneration, infection response, and treatment-induced cytotoxicity; unresolved questions include how apoptosis interacts with necroptosis, pyroptosis, ferroptos
Apoptosis Pathway
Apoptosis is a gene-controlled, active, and highly ordered process of programmed cell death that plays a pivotal role in embryonic development, the maintenance of tissue homeostasis, and the pathogenesis of various diseases. In biological research, the occurrence of apoptosis is typically assessed by monitoring characteristic physiological and biochemical markers, such as the externalization of phosphatidylserine (PS) on the cell membrane, activation of the caspase protease cascade, loss of mitochondrial membrane potential, and DNA fragmentation. Commonly used detection techniques include Annexin V/PI double-staining flow cytometry, the TUNEL assay (terminal deoxynucleotidyl transferase dUTP nick end labeling), caspase activity assays, and mitochondrial membrane potential analysis (using JC-1). These multidimensional quantitative and qualitative analytical methods provide a crucial experimental basis for elucidating the molecular regulatory networks of apoptosis and the pathogenic mechanisms of related diseases.
Related Experimental Schemes
