Apoptosisآپوپتوز

Apoptosisآپوپتوز

اسلاید 1: Apoptosis آپوپتوز

اسلاید 2: What is Apoptosis ?It is a form of programmed cell death that occurs in multicellular organisms.Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation.

اسلاید 3: Harakiri apoptosis

اسلاید 4: AdvantagesIn contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organisms lifecycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apoptotic bodies that phagocytic cells are able to engulf and remove before the contents of the cell can spill out onto surrounding cells and cause damage to them.

اسلاید 5: Activation mechanismsThe initiation of apoptosis is tightly regulated by activation mechanisms, because once apoptosis has begun, it inevitably leads to the death of the cell.The two best-understood activation mechanisms are the intrinsic pathway (also called the mitochondrial pathway) and the extrinsic pathway. The intrinsic pathway is activated by intracellular signals generated when cells are stressed and depends on the release of proteins from the intermembrane space of mitochondria. The extrinsic pathway is activated by extracellular ligands binding to cell-surface death receptors, which leads to the formation of the death-inducing signaling complex (DISC).

اسلاید 6: Bcl-2 familyThe Bcl-2 family proteins consists of members that either promote or inhibit apoptosis, and control apoptosis by governing mitochondrial outer membrane permeabilization (MOMP), which is a key step in the intrinsic pathway of apoptosis.Pro-apoptotic: BH3-only family ( Bim, Bid, Bal, BAD, Bcl-x(S) )Anti-apoptotic:Bcl-2 , Bcl-x(L)