BODY DIES STEM CELLS GO DORMANT AND SURVIVE FOR 2 WEEKS

 

Under the direction of Fabrice Chrétien, in collaboration with Shahragim Tajbakhsh, researchers from the Institut Pasteur, the Université de Versailles Saint-Quentin-en-Yvelines, the Paris Public Hospital Network (AP-HP), and the CNRS have shown for the first time in humans and mice, the capacity of stem cells to adopt a dormant state when their environment becomes hostile, including several days after death. This ability to significantly reduce metabolic activity enables them to preserve their potential for cellular division, even after extended periods post mortem. After isolation, they can then be used to repair damaged organs or tissues. This discovery could lead to new therapeutic avenues for treating numerous diseases. The study is being published in the journal Nature communications.
 

Remarkably, skeletal muscle stem cells can survive for seventeen days in humans and sixteen days in mice, post mortem well beyond the 1-2 days currently thought. This discovery was made by researchers from the Institut Pasteur, the Université de Versailles Saint-Quentin-en-Yvelines, the Paris Public Hospital Network (AP-HP), and the CNRS under the direction of Professor Fabrice Chrétien*, in collaboration with a team led by Professor Shahragim Tajbakhsh**. The scientists were also able to show that these stem cells, once back in culture, retained their capacity to differentiate into perfectly functioning muscle cells.
 

In light of this astonishing result, scientists then sought to characterize these cells to understand how they survive in such adverse conditions. They observed that these cells enter a deeper state of quiescence, drastically lowering their metabolism. This so-called "dormant" state is a result of cellular organization that is stripped to the bare minimum: fewer mitochondria (cellular power plants using oxygen to produce energy in cells) and diminished stores of energy.

“We can compare this to pathological conditions where cells are severely deficient in resources, before regaining a normal cell cycle for regenerating damaged tissues and organs, explains Fabrice Chrétien. When muscle is in the acute phase of a lesion, the distribution of oxygen is highly disrupted. We have even observed that muscle stem cells in anoxia (totally deprived of oxygen) at 4°C have a better survival rate than those regularly exposed to ambient levels of oxygen.”
 

The team of Fabrice Chrétien then wondered if these results were consistent with other cell types. Tests were then done on stem cells taken from bone marrow where blood cells are produced. These cells remained viable for four days in post mortem mice models, and more importantly, they retained their capacity to reconstitute tissue after a bone marrow transplant.
 

This discovery could form the basis of a new source, and more importantly new methods of conservation, for stem cells used to treat a number of pathologies. This is the case for leukemia, for example, which requires a bone marrow transplant to restore a patient's blood and immune cells destroyed by chemotherapy and radiation. By harvesting stem cells from the bone marrow of consenting donors post mortem, doctors could address to a certain extent the shortage of tissues and cells. Although highly promising, this approach in the realm of cellular therapy still requires more testing and validation before it can be used in clinical applications. Nevertheless, it paves the way to investigate the viability of stem cells from all tissues and organs post mortem.
 

Source: Institut Pasteur
 

From Don: "Scientists around the world are shocked, but they shouldn't be, because Repair Stem Cells are created to divide, grow and cure, no matter what the obstacles. There are many many obstacles which can slow or stop that repair, but we are constantly finding ways around them.  Now we know it will be possible in the future to collect stem cells (which are smart enough to go dormant) from a recently deceased body, test them, and use them to help another patient."