| Popis: |
Regulation of cell and tissue homeostasis requires balance between cell survival and death. Cell death is an active process in multicellular organisms as it eliminates potentially harmful cells and maintains tissue homeostasis. Apoptosis (type I cell death), autophagic cell death (type II), and necrosis (type III) are three types of morphologically distinct cell death. These three types of cell death are executed through distinct, and sometimes overlapping, signaling pathways that are engaged in response to specific stimuli. For various processes like natural cell turnover, proper development and functioning of the immune system, hormone-dependent atrophy, embryonic growth, and cell death triggered by chemicals, apoptosis is considered as an essential component. Apoptotic cells are characterized by specific morphologic and biochemical changes orchestrated by the family of cysteine proteases known as caspases. Caspases are essential apoptosis effectors. There are two primary pathways through which cells undergoes apoptosis, the extrinsic pathway (pathway of death receptor) and the intrinsic pathway (pathway of the mitochondrial). Apoptosis deregulation may lead to numerous pathological disorders such as developmental defects, autoimmune diseases, neurodegeneration, or cell cancer (e.g., during development), resulting in individual cell deaths. The main aim of this review is to give detailed description of apoptosis including its morphology, occurrence, and mechanism. |
