Stem cells weave a web of hope
University of Toronto investigators showed that injecting endothelial progenitor cells (EPCs) into the pulmonary circulation of rats results in microvasculature regeneration, a process they say might translate into therapy for pulmonary arterial hypertension. Current treatment of PAH, a rare but deadly disease of largely unknown origin, is merely palliative. Team leader Duncan Stewart says that research to date has missed the point by focusing on the larger pulmonary vessels rather than on the delicate web of capillaries that form the microcirculation.
The team derived EPCs from stem cells of rat bone marrow. Three days following induction of experimental PAH with the toxic chemical monocrotaline, EPCs were injected directly into the pulmonary artery. "Our findings were striking," says Stewart. "Thirty days posttransplant, EPCs had migrated efficiently into the lungs and engrafted into the microvascular endothelium, repairing small arterioles and even capillaries." These microcirculatory changes, ...
