We managed to transform human connective tissue cells – fibroblasts, directly into blood stem cells, bypassing the stage of restoring the pluripotent state, i.e. full undifferentiation, according to scientists from Canada in the journal Nature.
Blood stem cells are cells from which all types of blood cells can be made. Unfortunately, their availability is limited, as is the case with other types of stem cells, e.g. neuronal stem cells – which is why research has been carried out for years on the transformation of mature connective tissue cells, the so-called fibroblasts into stem cells. This was first achieved in 2007, when US scientists developed a method to turn human fibroblasts into cells at a developmental stage, such as embryonic stem cells. The method was based on a small genetic trick (introducing 4 transcription factors into the DNA of fibroblasts) and for the first time did not require the use of embryos.
The unique feature of stem cells is pluripotency, i.e. the state of complete undifferentiation and the possibility of development into any type of cell in the body. Until now, when converting fibroblasts into blood stem cells (which are already more developmentally oriented), it was first necessary to completely restart them and restore them to a state of pluripotency. Unfortunately, this type of manipulation was limited by the lack of full knowledge about the processes of cell differentiation and the risk of the initiation of processes of uncontrolled cell division and neoplasm.
Mickie Bhatia and colleagues at McMaster University in Hamilton, Canada, have transformed human skin fibroblasts into blood stem cells using a transcription factor called OCT4 (a key protein regulating the expression of stem cell genes) and cytokines (proteins responsible for cell division, growth and differentiation). from which any blood cells can be formed. This was achieved without the need to convert fibroblasts to the pluripotent state, thus avoiding technical complications and the risk of tumor initiation.
Moreover, and very importantly, the technique allows obtaining blood cells from the patient’s own fibroblasts, which eliminates the risk of transplant rejection and the serious problem of the lack of a sufficient number of donors.
Thanks to the work of Canadian scientists, it will be possible to easily and safely create blood stem cells for transplantation from fibroblasts of patients with blood diseases, bone marrow and people after chemotherapy. (PAP)