Mysterious blood factor responsible for blood clot formation
Around fifty years after the "Hageman factor", a blood coagulation protein also known as factor XII, was first described, a hitherto unrecognized function of the protein has been discovered. As two researchers have now discovered, it could apparently also play a crucial role in stroke and heart attack.
Biomedical scientists from the Würzburg Rudolf Virchow Center and the Würzburg University discovered this in experiments with so-called knockout mice in which the gene for the production of the protein was switched off. In animals with this defect, blood clots could no longer block off injured arteries from blood flow. The first plugs formed in the vicinity of the wound, but did not anchor themselves sufficiently close to the vessel wall as usual.
Previously it was assumed that the factor plays no role in blood clotting because people with defective Hageman factor (the "Hageman syndrome") have blood clotting rates at a normal rate and spontaneous bleeding does not occur in them. However, the researchers conclude from their results that the protein is important in the formation of thrombi in the blood vessels. They also disprove the dogma that blood clotting and blood clot formation occur via the same pathway.
The Hageman factor could be a promising therapeutic approach, Nieswandt now hopes. If it is possible to switch it off, an effective strategy against stroke and heart attack has been found which - unlike aspirin and the like - does not impair blood clotting.