BLOG: Good Cell Death. Bad Cell Death


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After a spinal cord injury, cells die. But not all cell death is the same. Understanding and preventing the different types of cell death is important for a cure.

 

About 1 million cells die every second in a healthy person. And that without external influences. But that's far less dramatic than it sounds. The healthy organism needs “programmed cell death” - apoptosis. Most types of body cells have done their “duty” after a certain lifetime. The cells themselves then ring the bell of death. They shrink and disintegrate into small fragments. This is a normal and controlled process. New, functional cells replace them and replace the old ones. 

Cell death in a few minutes
More dangerous is a morbid, uncontrolled cell death - a so-called necrosis. External influences, such as direct injury, create extreme conditions and damage the cells. These can then swell and burst within a few minutes. They empty their contents and trigger inflammation in the surrounding tissue. This will kill more cells.

Apoptosis and necrosis in spinal cord injury
At the point of injury, there is an immediate destruction of neurons, glial cells and blood vessels.
In this primary phase, there is a necrosis of many cells in the spinal cord; a toxic, low-oxygen environment is created. A few minutes later, the secondary phase begins, which can take several weeks. This environment further promotes necrosis and the amount of dead tissue increases.

In the secondary phase, a programmed cell death of the glial cells is also added. This means that undamaged cells that are still needed destroy themselves. How apoptosis is triggered in glial cells is not fully understood yet. It could be an attempt by the body to contain damage. Because programmed cell death does not create a toxic environment that would provoke further necrosis.

Stop cell death
The more widespread cell death occurs, the more severe the loss of function in spinal cord injury could be. Therefore, it is important to control the cell death.
One consideration is to limit the extent of the toxic environment, for example with hypothermia.
Another approach pursues the idea of preventing apoptosis in glial cells. For example, the antibiotic minocycline seems to successfully affect programmed cell death. This is currently being tested in a clinical trial.

Although much remains to be researched into the causes and effects of cell death, successful results have already been achieved for the development of a possible therapy. The control of cell death is a promising piece of the puzzle that contributes to the recovery of a spinal cord injury.

Vieri Failli is a doctor of neuroscience, but has a passion for bringing the general public closer to the most complex questions of science
Vieri Failli is a doctor of neuroscience, but has a passion for bringing the general public closer to the most complex questions of science