Since the year 2000, much has been learned about the potential for using transplanted cells in therapeutic efforts to treat varieties of cardiac disorders. Recently at the Third Annual Conference on Cell Therapy for Cardiovascular Disease, New York, McGowan Institute faculty member Amit Patel, MD, MS, Director of Cardiac Stem Cell Therapies, University of Pittsburgh Medical Center, presented his team’s research results that hope to move cell transplantation for heart patients closer to reality.
“Cardiac stem cell therapy involves delivering a variety of cells into hearts following myocardial infarction or chronic cardiomyopathy,” says Dr. Patel, the lead author of an overview and introductory article, Cardiac Stem Cell Therapy from Bench to Bedside. “Many questions remain, such as what types of cells may be most efficacious. Questions about dose, delivery method, and how to follow transplanted cells once they are in the body and questions about safety issues need answers.”
According to Patel suitable sources of cells for cardiac transplant will depend on the types of diseases to be treated. For acute myocardial infarction, a cell that reduces myocardial necrosis and augments vascular blood flow will be desirable. For heart failure, cells that replace or promote myogenesis, reverse apoptopic mechanisms, and reactivate dormant cell processes will be useful.
Adult bone marrow-derived mensenchymal stem cells have shown great signaling and regenerative properties when delivered to heart tissues following a myocardial infarction. However, the poor survival of grafted cells has been a concern of researchers. Given the poor vascular supply after a heart attack and an active inflammatory process, grafted cells survive with difficulty. Transmyocardial revasularization (TMR), a process by which channels are created in heart tissues by laser or other means, can enhance oxygenated blood supply.
"We hypothesized that using TMR as a scar pretreatment to cell therapy might improve the microenvironment to enhance cell retention and long-term graft success," said Dr. Patel, lead author of the study titled Improved Cell Survival in Infarcted Myocardium Using a Novel Combination Transmyocardial Laser and Cell Delivery System. "TMR may act synergistically with signaling factors to have a more potent effect on myocardial remodeling."
Patel and colleagues, who used a novel delivery system to disperse cells in the TMR-generated channels in an animal model, report significant cell survival in the TMR+Cell group versus Cells or TMR alone. The researchers speculated that there was an increase in local production of growth factors that may have improved the survival of transplanted cells.
Illustration: McGowan Institute for Regenerative Medicine.
Cell News (12/27/07)
Medical News Today (12/28/07)
Science Daily (12/30/07)
Proceedings, Third Annual Conference on Cell Therapy for Cardiovascular Disease, New York, NY
Abstract (Cell Transplantation, Vol. 16, pp. 899-906, 2007)