Stem cells that rust

Scientists from Lund University have discovered that certain cells during embryonic development are negatively affected by oxidation — the same process that causes rust in metal. Their study, published in the journal Stem Cells, finds that this oxidation is capable of leading to a block in cellular function.

The research team had been using a laboratory-based culture system to generate new blood from human pluripotent stem cells (hPSCs); they hope in the future to be able to use the system to generate new blood cells for patients in need of bone marrow transplants. However, laboratories worldwide attempting to generate laboratory-derived blood cells have determined that these cells do not perform as well as blood cells from donor sources. The cells appear normal but do not grow and expand as well.

When investigating the reason for this, the researchers found high levels of reactive oxygen species (ROS) — a class of molecules that cause oxidation — in the newly derived blood cells. The levels were high enough to damage the cells and cause them not to grow in culture.

The researchers went on to develop a cocktail of factors that could reduce oxidative damage in the cells. When used, these resulted in a 22-fold increase in growth capacity for the newly generated blood stem cells.

“By identifying the negative role of oxidation in new blood cells derived from pluripotent stem cells, we have identified what is perhaps the most significant hurdle in developing laboratory-derived blood stem cells for transplantation-based therapies,” said study leader Niels-Bjarne Woods.