Vast self-renewal potential of embryonic blood stem cells versus cord blood

17 Sep 2020

 One transplanted haematopoietic stem cell can generate 500 times more daughter cells if from the human embryonic AGM region
One haematopoietic stem cell from the human AGM region can generate upon transplantation 500 times more daughter cells in an immunocompromised mouse than a cell from umbilical cord blood. \n

A new study has shown that very early in development, human stem cells that go on to produce adult blood and immune cells have a huge regenerative potential.

Blood stem cells (haematopoietic stem cells) can be transplanted to treat blood diseases such as leukaemia. These cells can be sourced from donor bone marrow or umbilical cord blood. Supply of cord blood is limited, reliant on collection at birth from the individual or from donors. Scientists are searching for ways of maximising the use of these limited samples. 

The first haematopoietic stem cells are found in an area of the embryo called the aorta-gonad-mesonephros (AGM) region. This study compared the self-renewal potential of human AGM haematopoietic stem cells to that of human umbilical cord haematopoietic stem cells.

Professor Alexander Medvinsky, Andrejs Ivanovs and colleagues transplanted human AGM cells into mice with a poor immune response. Each implanted cell was shown to produce up to 1,600 viable haematopoietic stem cells. This is up to 500 times more than implanted umbilical cord blood haematopoietic stem cells.

Building an understanding of what makes the AGM cells so much more potent than cord blood stem cells could, in future, help to improve the capacity of cord blood samples in the treatment of disease. Professor Medvinsky said,

“Here, we provide evidence that the first haematopoietic stem cells emerging in the human embryo have enormous regenerative potential.

“Understanding the molecular mechanisms that underpin their regenerative capacity could be very useful to help produce them in the laboratory or to enhance the regenerative capacity of haematopoietic stem cells from the umbilical cord blood in a clinical setting.”

Professor Alexander Medvinsky

This study was published in Stem Cell Reports and was supported by funding from the Medical Research Council.

Stem Cell Reports article

At the same time, Medvinsky and colleagues have also published results mapping the molecular landscape of important regulators of human AGM cell production. These insights will allow scientists to develop and test new ideas about how this complex process is controlled.

Mapping the molecular landscape of embryonic blood stem cell emergence - CRM News