Monday, July 22, 2013
Chemically induced pluripotent stem cells
Scientists have been able to reprogram the mature human stem cells, using only the chemical compound (without genetic manipulation).
A new method of obtaining cells are as versatile as embryonic stem cells, reduces the risk of developing cancer or of mutations that can occur as a result of stem cell therapies, "reprogrammed" with the introduction of additional genes.
Since then, in 2006, it was announced the discovery of induced pluripotent stem cells ( iPSCs ), scientists have sought to reduce the number of additional genes required for such cells. But it is always required at least one encoding a protein Oct-4 .
Researchers from Beijing have studied thousands of low molecular weight compounds in the search for the one that will be able to reprogram cells without Oct -4, but in the presence of three other genes required for iPSC. Finding such a connection, the researchers looked for substitutes and for the remaining three genes involved in reprogramming. Adding DZNep - compound catalyzing reprogramming process at a late stage - the scientists finally got the stem cells, but in very small quantities necessary to add another compound to increase the efficiency of the process 40 times.
As a result, researchers, amounting to a "cocktail" of several compounds were able to achieve transformation of stem cells in 0.2% of the initial amount - a result comparable with the efficiency of modern methods of obtaining iPSCs. The cells introduced into mouse embryos successfully differentiated into various types of tissues, including liver, heart, brain, skin and muscle.
Further research in this area may lead to new discoveries in the field of regenerative medicine - for example, the answer to the question of how some frogs manage to re-grow severed limbs. Scientists know that before the regeneration process starts animal cells similar to their reprogramming into pluripotent stem.
If the method is found to be safe, it can be used in clinical practice. It reduces the risk of mutation and used chemical compounds are likely to be safe - four of them are already used in medicine. Small molecules can pass through cell membranes, so they can "wash away" after they start the process of reprogramming.
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