Human Blood Cells Directly Reprogrammed Into Neural Stem Cells

For the first time scientists from the German Cancer Research Center and the stem cell institute HI-STEM have directly reprogrammed human blood cells into neural stem cells; the induced stem cells are similar to those occurring during early embryonic development of the central nervous system, and can be modified and multiplied indefinitely in culture dishes representing an important basis for development of regenerative therapies.

Stem cells are the all rounders of body tissues that can multiply indefinitely and if they are pluripotent embryonic stem cell they can generate all conceivable cell types. 4 genetic factors are sufficient to reverse the course of development and produce iPs which have identical properties to embryonic stem cells; Shinya Yamanaka was awarded the Nobel Prize for Medicine in 2012 for making this discovery.

Human embryonic stem cell generation is not permitted in Germany, making such discoveries of great importance as stem cell carry much potential for research and development of regenerative therapies aiming to restore diseased tissues. Reprogramming is associated with problems such as pluripotent cells can form teratomas germline tumors.

Other research has reprogrammed connective tissue cells into mature nerve cells or neural precursor cells, however these artificially produced nerve cells could often not be expanded and could not be used for therapeutic purposes; most often it was a heterogeneous mixture of varying cells types that may not exist within the body under physiological conditions explains Andreas Trumpp.

The team has succeeded in reprogramming different human cells; connective tissue cells of the skin or pancreas, and peripheral blood cells; possibility of extracting neural stem cells from patient blood without invasive intervention is a huge advantage for future therapeutic approaches.

These regrammed cells are a homogeneous cell type resembling a stage of neural stems cells that occur during embryonic development of the nervous system, the team has described a new neural stem cell type in the mammalian embryo with braid development potential: induced Neural Plate Border Stem Cells.

INBSCs are expandable, multipotent, and can develop in two different directions: taking on the path of development to mature nerve cells and their supplier cells, the glial cells, becoming cells of the central nervous system; and develop into cells of the neural crest from which different cell types emerge such as peripheral sensitive nerve cells of cartilage and bones of the skull. Therefore iNBSCs form an ideal basis for generating a broad range of different cell types for patients having the same genetic material as the donor which presumably will be recognized as self by the immune system and not be rejected.

CRISPR/Cas9 gene editing can be used to modify iNBSCs or repair defects, making them interesting for basic research, searches for new active substances, and for the development of regenerative therapies. Much more research must be done until they can be used in patients, and even more once they can be emphasizes Trumpp.