Erebosis
A new type of programmed cell death has been discovered in the fly's intestines
Alexandra Medvedeva, Naked Science
Programmed death occurs due to intracellular processes. It allows you to remove damaged or diseased cells before they have time to harm the body. Today there are more than ten different types of cell death, among which apoptosis is the most famous.
Now scientists from the RIKEN Biosystems Dynamics Research Center (Japan) have discovered a completely new type of cell death occurring in the intestines of the common fruit fly. This process, called erebosis, plays an important role in intestinal metabolism. The results of the work published in the journal PLoS Biology (Ciesielski et al., Erebosis, a new cell death mechanism during homeostatic turnover of gut enterocytes) call into question the generally accepted concept of programmed cell death and refute the previously existing theory of intestinal homeostasis.
During erebosis, cells lose fluorescent proteins and become "black". / © RIKEN.
The cells that make up the intestine are constantly being updated. The traditional theory says that aging and damaged cells die as a result of apoptosis. During this process, the cell breaks up into separate corpuscles, limited by the plasma membrane, which are destroyed by immune cells within 1-3 hours. However, a new study has provided evidence for the existence of a different type of cell death specific to the intestine.
Scientists have studied the enzyme ANCE, responsible for reducing pressure. They noticed that the expression of ANCE in the intestines of flies was heterogeneous, and the cells containing it looked strange. Later, scientists found that these cells were dying: they were dark, devoid of nuclear membranes, mitochondria and cytoskeleton, and sometimes even DNA and other cellular elements necessary for survival.
The name "erebos" comes from the Greek word erebos — "darkness". It passes gradually, unlike rapid apoptosis. Cells containing ANCE were often located near the sites of formation of new intestinal cells, so scientists have suggested that erebosis is associated with tissue renewal.
After that, the researchers showed that stopping apoptosis does not interfere with the normal renewal of intestinal cells. In addition, none of the molecular markers of apoptosis or other known types of programmed death were found in dying cells. Only in the late stages of erebosis, cells isolated a common marker of cell death associated with DNA degradation.
It turned out that the ANCE enzyme, which was the reason for the discovery, probably does not directly participate in erebosis, since changes in its expression did not affect the process itself in any way. Therefore, scientists seek to uncover the molecular mechanisms of erebosis, and in addition, to find out whether it passes in the intestines of other animals, including humans.
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