Non-Invasive Tool Monitors Effects of Stem Cell Treatments
Stem cell based therapies to strengthen the heart muscle and treat other diseases are beginning to show promise in human clinical trials. But the lack of a repeatable, time-sensitive and non-invasive tool to assess the effectiveness of the transplanted cells within the target organ has slowed progress in the field.
Researchers from three US universities have been working to develop a blood test that could be used to track the efficacy of transplanted stem cells. They analysed tiny cellular components called exosomes, secreted from the transplanted stem cells into the recipient blood. They tested their theory in rodent models of heart attack, or myocardial infarction, after transplanting two types of human cardiac stem cells and monitoring their circulating exosomes. The researchers found circulating exosomes delivered cell components to the target heart muscle cells, resulting in cardiac repair. Results are published in the journal Science Translational Medicine.
“Exosomes contain the signals of the cells they’re derived from,” explained study co-author Dr Sunjay Kaushal, Professor of Surgery at the University of Maryland. “We now have a tool to determine whether stem cell therapy will be efficacious for an individual patient, not only for the heart but for any organ that received stem cell therapy.”
Through the blood test, which the researchers call a “liquid biopsy,” the researchers monitored human cardiosphere-derived cells (CDCs) and cardiac progenitor cells (CPCs) transplanted into rat hearts following myocardial infarction. Blood plasma concentrations of the exosomes were compared seven days after transplant.
The researchers found the exosomes contained micro RNAs associated with heart muscle recovery. Further, they found CPCs and CDCs produced in culture differed in contents from exosomes produced by transplanted cells in the living organism.
Science Daily. May 22. Science: Translational Medicine. May 22.