Diagnostic Pathology: Open Access
Open Access

Apoptosis, or programmed cell death, is defined by specific morphological traits as well as energy-dependent molecular pathways. Apoptosis is thought to be important in a variety of activities, including normal cell turnover, immune system development and function, hormone-dependent atrophy, embryonic development, and chemical-induced cell death. Apoptosis that is either too little or too much is a factor in a variety of human diseases, including neurodegenerative diseases, ischemia damage, autoimmune disorders, and cancer.

The power to control whether a cell lives or dies is recognized for its enormous therapeutic potential. As a result, scientists are still working to understand and analyses the cell cycle machinery and signaling networks that control cell cycle arrest and apoptosis. To that purpose, apoptosis research has been progressing at an alarmingly fast pace. Although many of the important apoptotic proteins have been identified, the molecular mechanisms by which these proteins operate or do not act are still unknown. The purpose of this study is to present a comprehensive overview of current understanding about apoptosis, including morphology, biochemistry, and the significance of apoptosis in health and disease, as well as detection methods and a discussion of prospective alternative approaches.

Necrosis, which is a toxic process in which the cell is a passive victim and dies in an energy-independent manner, is an alternative to apoptotic cell death. However, because necrosis refers to the degradative processes that occur after cell death, some people believe it is an improper phrase to use to describe a cell death mechanism. As a result, oncosis is used to define a process that results in necrosis, karyolysis, and cell swelling, whereas apoptosis results in cell death, pyknosis, and karyorrhexis. As a result, the names "oncotic cell death" and "oncotic necrosis" have been proposed as replacements to characterize cell death that is accompanied by cell swelling, but these concepts are not yet generally preferred.

Apoptosis and necrosis have different mechanisms and morphologies, yet there is overlap between the two. Evidence suggests that necrosis and apoptosis are morphologic representations of the apoptosis-necrosis continuum, a common metabolic network. A decrease in the availability of caspases and intracellular ATP, for example, are two elements that will turn an ongoing apoptotic process into a necrotic phase. The nature of the cell death signal, the tissue type, the developmental stage of the tissue, and the physiologic milieu all have a role in whether a cell dies through necrosis or apoptosis. It's not always possible to tell the difference between apoptosis and necrosis using traditional histology, and they can happen at the same time depending on aspects like the stimulus's intensity and duration, as well as the stimulus's location.

Apoptosis is a controlled and energy-dependent process that can affect individual or clusters of cells, whereas necrosis is an uncontrolled and passive process that frequently affects huge fields of cells. Interference with the cell's energy supply and direct damage to cell membranes are the two basic mechanisms that cause necrosis. Cell swelling, formation of cytoplasmic vacuoles, distended endoplasmic reticulum, and formation of cytoplasmic blebs, condensed, swollen, or ruptured mitochondria, disaggregation and detachment of ribosomes, disrupted organelle membranes, swollen and ruptured lysosomes, and eventually disruption of the cell membrane are some of the major morphological changes that occur with necrosis.

The cytoplasmic contents are released into the surrounding tissue as a result of the breakdown of cell membrane integrity, conveying chemotactic signals and eventually attracting inflammatory cells. There is essentially no inflammatory response because apoptotic cells do not release their cellular elements into the surrounding interstitial tissue and are immediately phagocytosed by macrophages or neighbouring normal cells. It's also worth noting that pyknosis and karyorrhexis aren't just associated with apoptosis; they can also be found in the range of cytomorphological changes associated with necrosis.