General view of the cytoplasmic and nuclear features of apoptosis

The process of apoptosis is generally characterized by the existence of cytoplasmic and mitochondrial pathways that undergo nuclear events, leading to the cell death. The cellular machinery of apoptosis relies on an energy‐dependent biochemical mechanism will distinct morphological characteristics. Apoptosis may be considered an important molecular mechanism that takes place on a cell to maintain the normal cell turnover, immunologic system, hormone‐dependent atrophy, embryonic development and chemical‐induced cell death. However, upon certain pathological conditions, inappropriate apoptosis can trigger both life and death stimuli, leading to many human disorders, such as human neurodegenerative diseases, autoimmune disorders, and different types of cancer. An understanding of how apoptosis machinery works in a specific cell context and upon certain stimuli would allow the development of novel therapy strategies. In the current chapter, we discuss the role of the cytoplasmic features of apoptosis, including the perforin/granzyme pathway (Granzyme A and Granzyme B pathways), as well as the extrinsic pathways into the context of cellular life‐or‐death decision. To note, a detailed scenario of the intrinsic pathway exceeds the scope of this chapter and has been covered elsewhere in the book (i.e., second chapter). Moreover, we discuss the main nuclear events of the execution phase of apoptosis. In detail, we address how the contribution made by many apoptosis pathways has deepened our understanding of human diseases.