Cytoplasm during apoptotic cells, is condensed, has condensed chromatin, and the nucleus undergoes pyknosis -irrevessible condensation if chromatin, which is followed by karyorrhexis – destructive fragmentation of nucleus. Nuclear fragmentation precedes inter-nucleosomal ordered degradation of nuclear DNA to form a progressively smaller fragments up to 180 base pairs.
The collapse of the DNA in the nucleosome-specific fragments with discontinuities nucleotide chain, leads to DNA fragments of different lengths to occur. In the final stage of apoptosis, cells themselves are fragmented to a form the so-called apoptotic cells – surrounded by a membrane fragments of cells, including the remnants of organelles, cytoplasm and chromatin. Those apoptotic cells are engulfed by macrophages and granulocytes, phagocytosis is not accompanied by local inflammation.
Examples of apoptosis
Programmed cell death – a natural process of massive cell death and elimination of entire clones during embryonic development, histogenesis and morphogenesis of organs. In this case we are talking about the death of cells that have not reached the state of terminal differentiation. An example is the programmed death of neuroblasts (25 to 75%) at certain stages of brain development.
The death of cells that have fulfilled their function – Cells that have fulfilled their function, die by apoptosis. For example, the removal of the clones of immune cells by the immune response -eosinophils die after degranulation.
The mechanism of cell death, at the point of terminal differentiation and fulfilled its function has not been studied, but it is clear that it is genetically determined. Thus, the expression of FOS gene is a marker of terminal differentiation and simultaneously precedes the cell death.
Degeneration - Under certain pathological conditions, relatively selective cell death is experienced. For example, in the nervous system with amyotrophic lateral sclerosis (Lou Gehrig’s disease) and Alzheimer’s disease, congenital form of amyotrophic lateral sclerosis caused by a mutation of the gene Cu / Zn-superoxide dismutase 1 -the product of the defective gene is not able to inhibit IL-1p-converting enzyme and the resulting IL-1p to effect motor neurons and cause them to go under apoptosis.
Elimination of autoaggressive T cells – For example, in the development of the thymus or deleting lymphocyte immune response implementation, elimination of tissue cells exposed to cytotoxic T lymphocytes or natural killer cells.
Aging – For example, by hormone-dependent involution of endometrial cells and atresia of ovarian follicles in women during menopause, regression of prostate and testicular tissue in older men.
Transfection – The introduction of the cell virus nucleic acid (eg, viral hepatitis, myocarditis, encephalitis, AIDS).
Cell damage – Effects on cell-damaging agents which do not lead to necrosis (eg, high temperature, radiation, hypoxia). Increasing the intensity of these effects may lead to necrosis as usual.
Tumor growth – Apoptosis is detected as the formation of the tumor site, and during its destruction.
The collapse of the DNA in the nucleosome-specific fragments with discontinuities nucleotide chain, leads to DNA fragments of different lengths to occur. In the final stage of apoptosis, cells themselves are fragmented to a form the so-called apoptotic cells – surrounded by a membrane fragments of cells, including the remnants of organelles, cytoplasm and chromatin. Those apoptotic cells are engulfed by macrophages and granulocytes, phagocytosis is not accompanied by local inflammation.
Examples of apoptosis
Programmed cell death – a natural process of massive cell death and elimination of entire clones during embryonic development, histogenesis and morphogenesis of organs. In this case we are talking about the death of cells that have not reached the state of terminal differentiation. An example is the programmed death of neuroblasts (25 to 75%) at certain stages of brain development.
The death of cells that have fulfilled their function – Cells that have fulfilled their function, die by apoptosis. For example, the removal of the clones of immune cells by the immune response -eosinophils die after degranulation.
The mechanism of cell death, at the point of terminal differentiation and fulfilled its function has not been studied, but it is clear that it is genetically determined. Thus, the expression of FOS gene is a marker of terminal differentiation and simultaneously precedes the cell death.
Degeneration - Under certain pathological conditions, relatively selective cell death is experienced. For example, in the nervous system with amyotrophic lateral sclerosis (Lou Gehrig’s disease) and Alzheimer’s disease, congenital form of amyotrophic lateral sclerosis caused by a mutation of the gene Cu / Zn-superoxide dismutase 1 -the product of the defective gene is not able to inhibit IL-1p-converting enzyme and the resulting IL-1p to effect motor neurons and cause them to go under apoptosis.
Elimination of autoaggressive T cells – For example, in the development of the thymus or deleting lymphocyte immune response implementation, elimination of tissue cells exposed to cytotoxic T lymphocytes or natural killer cells.
Aging – For example, by hormone-dependent involution of endometrial cells and atresia of ovarian follicles in women during menopause, regression of prostate and testicular tissue in older men.
Transfection – The introduction of the cell virus nucleic acid (eg, viral hepatitis, myocarditis, encephalitis, AIDS).
Cell damage – Effects on cell-damaging agents which do not lead to necrosis (eg, high temperature, radiation, hypoxia). Increasing the intensity of these effects may lead to necrosis as usual.
Tumor growth – Apoptosis is detected as the formation of the tumor site, and during its destruction.
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