A group of scientists at the University of Tsukuba have been successful at creating novel culture system that can pave path for ex-vivo expansion of Hematopoietic Stem Cells (HSC). Generally, HSCs are immature blood cells which when triggered can mature into any other blood cell type. So, in cases where the bone marrow is dysfunctional or not able to produce the viable blood cells, HSC transplants can be used. However, their real life application has been limited due to restriction in cell growth and lab expansion.
Why not use umbilical cord blood for stem cells?
You must have thought of this that why do we need such large scale production when we can fetch HSCs from umbilical cord blood. Well, the reason is, for HSC transplantation the yield needs to be sufficient for proper transplantation to occur and this is difficult to achieve from cord blood. Ex-vivo expansion therefor becomes important and many researchers have earlier tried to achieve it by using cytokines and albumin protein, but no efficient long term results were obtained.
Prof. Saroshi Yamazaki said, “Other teams have shown promising results using novel approaches for HSC ex vivo expansion, including the addition of small molecules, certain hydrogels, various growth factors, or small molecule inhibitors to the cell culture media,”.
In the latest findings, researchers replaced the albumin with a synthetic polymer, which prevented the variability and impurities that arises between batches due to albumin (in mouse HSCs). However, when the same was applied to human HSCs, the efficiency was not up to the mark. This was due to reduced activity of signalling molecules like PI3K and AKT. To overcome this challenge, they used chemicals which activates these molecules, thus increasing the human HSC growth. Compounds like UM171 as well as a specific polymer added, showed improved results for HSC expansion. This was further confirmed by RNA sequencing, where successful effect of this system was observed on gene expression of respective cells. The HSCs transplant in mice further showed positive engraftment results along with healthy growth of cells, expanded using this new culture system.
Has possibility to transform the stem cells future
Given the importance of ex-vivo expansion of human HSCs, there is no doubt that the new culture system will be the next big thing in the field. It has provided a robust alternative to traditional methods. This can help in solving the real life problems and can be used efficiently in HSC related therapeutics to save millions of lives.
