solukkuolema

Solukuolema (cell death) refers to the set of cellular processes that lead to the systematic elimination of cells. It is essential for development, maintaining tissue homeostasis, and removing damaged or dangerous cells. There are two broad categories: regulated programmed cell death and accidental cell death caused by injury.

The most studied form of programmed cell death is apoptosis, which is an orderly, energy-dependent process. Cells undergoing apoptosis exhibit characteristic changes such as shrinkage, chromatin condensation, DNA fragmentation, membrane blebbing, and formation of apoptotic bodies that are cleared by phagocytes. Apoptosis is driven by proteolytic enzymes called caspases and is controlled by signaling pathways, including the intrinsic (mitochondrial) pathway and the extrinsic (death receptor) pathway. The balance between pro-apoptotic and anti-apoptotic Bcl-2 family proteins helps determine a cell’s fate.

Beyond apoptosis, several other regulated forms of cell death have been identified, including necroptosis, ferroptosis, and pyroptosis, each with distinct triggers and molecular mechanisms. Autophagic processes can contribute to cell death under certain stresses, though autophagy more commonly promotes cell survival. Necrosis, traditionally viewed as uncontrolled, can occur due to acute injury and often elicits inflammation.

Dysregulation of solukuolema is linked to many diseases. For example, cancer may involve evasion of apoptosis, while excessive cell death contributes to neurodegenerative and ischemic conditions. Understanding these processes supports research into therapies that either trigger death in diseased cells or prevent unwanted loss in healthy tissues. Detection of cell death uses assays for caspase activity, phosphatidylserine exposure (Annexin V), DNA fragmentation, and morphological assessment.