Researchers from the University of Maryland, University of Pennsylvania, and Emory University have demonstrated that a blood test can be used to track the efficacy of transplanted stem cells. They analyzed tiny cellular components called exosomes that were secreted from transplanted stem cells.
“Exosomes contain the signals of the cells they’re derived from – proteins as well as nucleic acids and micro ribonucleic acids (miRNAs) – which affect receptor cells and remodel or regenerate the organ we’re targeting,” said study co-senior author Sunjay Kaushal, PhD, MD, Professor of Surgery at UMSOM and Director of Pediatric Cardiac Surgery at the University of Maryland Children’s Hospital. “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.”
The blood test, also called a liquid biopsy, was used to monitor human cardiosphere-derived cells (CDCs) and cardiac progenitor cells (CPCs) which were implanted into rat hearts after induced heart attacks. The researchers studied blood plasma concentrations of exosomes for a week after transplantation. After purifying the CDC/CPC-derived exosomes, the researchers found they contained miRNAs associated with heart muscle recovery. Interestingly, they found that the contents of the exosomes in vivo differed substantially from what they had produced in vitro, indicating that the cell phenotype had changed after transplantation.
Being able to monitor these exosomes represents an important way to monitor stem cell transplantation therapies and evaluate their performance over time.
“Our study should be considered the first stepping stone in understanding what stem cells do, but an important point is that the cells we identified as responding changed their gene expression, behavior and secretions,” said co-lead author Sudhish Sharma, PhD, UMSOM Assistant Professor of Surgery. “By using these biomarkers, we can understand the mechanism and extent of recovery.”
Here’s Dr. Kaushal explaining the study in his own words:
The publication in Science Advances: Circulating exosomes derived from transplanted progenitor cells aid the functional recovery of ischemic myocardium…