Molecular and Biological Mechanisms of Apoptosis and its Detection Techniques

Abstract

the end of indications of life and is caused by functional irregularity. Cell death is genetically controlled and can be categorized into programmed, such as apoptosis and autophagy, and unprogrammed, such as necrosis. Apoptosis is an active self-destruction process, which is influenced by a diversity of stimuli that induce highly similar structural changes. These morphological changes are chromatin build-up, cytoplasmic shrinkage, zeiosis and the arrangement of apoptotic bodies inside the nucleus. The concluding phase of apoptosis is characterized by cytoplasmic membrane fragmentation and phagocytosis of debris by macrophages or adjacent cells. Figure 1 illustrates typical changes in the cells undergoing apoptosis or necrosis and the possible differences are tabulated in Table 1. Death by apoptosis is differentiated from death by necrosis by the absence of inflammatory responses. Early in 1972, these observations were reported by Kerr et al. but were less significant in those days.1 However, from embryogenesis to aging and from the normal tissue homeostasis to many diseases, apoptosis has been found to occur in various life stages and has become a field of importance in developmental biology, biogerontology, and cancer research. Malfunctioned apoptotic cascade may lead to several diseases like cancer due to its decreased rate and causes strokes and neurodegenerative disorders such as Alzheimer’s, Huntington and Parkinson’s diseases in an exaggerated state. Table 2 presents the timeline of cell death research.