Apoptotic and Non-apoptotic Cell Death

_Apoptosis is a prototype of regulated cell death and is executed by the sequential activation of caspases, and plays a crucial role in the process for development and tissue homeostasis of multicellular organisms. In the process of apoptosis, dead cells produce a "find me" signal to recruit phagocytes, and present an "eat me" signal. The prompt clearance of dead cells by phagocytes prevents the release of noxious materials from dying cells that may activate the immune system to develop autoimmune diseases. In addition, apoptotic cells release various factors that are involved in inflammation, proliferation, immune tolerance, and tissue repair in a context dependent manner. In addition to apoptosis, current studies revealed various types of non-apoptotic forms of cell death including regulated necrosis, pyroptosis, entosis, and ferroptosis etc. Among them, the regulated necrosis, also called necroptosis, plays a crucial role in ischemic reperfusion injury, drug-induced pancreatitis, and elimination of virus infection. Whereas, pyroptosis is the cell death induced by bacteria or viral infection, and entosis is the killing through the cell-in cell structure. The molecular mechanisms of these cell death processes are currently extensively studied. In this text book, current advances of cell death research and its future direction will be introduced and discussed.