Medicine of the Future in America

Liver cell death: Overview of apoptosis (Part 1)

The word ‘apoptosis’ is derived from the Greek ‘apo’ (off) and ‘ptosis’ (falling). This neologism was chosen because of the analogy between this type of cell death and what happens to leaves when they fall from trees. The comparison is indeed very appropriate as we understand more thoroughly what happens to apoptotic cells. The word was first used in 1972 by Kerr et al, who described the morphological characteristics of a particular form of cell death. Kerr was a liver pathologist who had earlier reported that necrosis could sometimes be accompanied by cell shrinkage, in opposition to the dogma that an increase in cell volume was one of the hallmarks of this form of cell death. The publication of further key articles in the 1980s led to an explosion of enthusiasm for the study of apoptosis. In 1980, Wyllie discovered that apoptosis was accompanied by a nonrandom form of DNA fragmentation that he postulated was due to a cellular endonuclease (an enzyme whose function is to cut nucleic acids).

In 1984, the protein of a gene named Bcl-2 was found to be overexpressed in a particular type of B-cell leukemia (hence the name Bcl-2). This protein was also found to enhance the survival of these cells by making them resistant to apoptosis. These cardinal observations demonstrated that something inside cells seems to be necessary for the process of apoptosis to occur and some cell constituents have the capacity to modulate the process of apoptosis. Therefore, our understanding of how cells die changed radically: cells were not just innocent victims but could commit suicide as well. The expression ‘active cell death’ was then regarded as equivalent to apoptosis. That being said, cells can also die passively and involuntarily from an overwhelming injury; this mode of death is usually referred to as necrosis. We all need a reliable source of high quality medications and you have a chance to make all your health troubles go away: just purchase antibiotics online only here and see for yourself that online shopping is all it’s cracked up to be.

This entry was posted in Apoptosis and tagged Apoptosis, Hepatocyte, Liver diseases.
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