Long term in vivo imaging of induced pluripotent stem cells in pig hearts
Latest research of international team headed by Prof. Ulrich Martin was published in the renowned journal Circulation
In the future, stem cell-based therapies will provide innovative therapeutic strategies for the treatment of various genetic and acquired diseases. Recently, the possibility to reprogram normal somatic cells into induced pluripotent stem cells (iPS cells) that are able to differentiate into all cell types present in the body, has opened novel opportunities for the regeneration of damaged organs, for example after a heart attack.
Major progress has been achieved over the past years with respect to the potential therapeutic application of these pluripotent stem cells. Though, clinical application of the cells, e.g., for the regeneration of heart tissue, still seems to be associated with incalculable risks. In order to evaluate and minimise these risks, clinically applicable imaging methods to monitor viable transplanted stem cell derivatives are required. These methods should allow for the tracking of the cells in not only preclinical animal models but later also in patients.
In the present study, the research team led by Professor Dr. Ulrich Martin - in collaboration with a group from Zürich - artificially introduced an ion channel into human iPS cells. Physiological occurrence of this ion channel is restricted to the thyroid and the stomach. Analogous to current thyroid diagnostics, this might allow for the monitoring of survival and distribution of transplanted stem cells in both animal model and patients. In fact, using modern clinical imaging methods, these modified iPS cells could be identified for up to 15 weeks after transplantation into the heart. Here, they differentiated into cells of the vascular system. Another encouraging finding was that during this time no so called teratoma, tumours derived from undifferentiated stem cells, were developed.
Stem cell researchers are in agreement about how valuable these new technologies are for the further development of current stem cell based therapies and about their importance for risk evaluation and minimisation.
Templin C, Zweigerdt R, Schwanke K, Olmer R, Ghadri J-R, Emmert MY, Mueller E, Kueest SM, Cohrs S, Schibli R, Kronen P, Hilbe M, Reinisch A, Strunk D, Haverich A, Hoerstrup S, Luescher TF, Kaufmann PA, Landmesser U*, Martin U*: Transplantation and tracking of human-induced pluripotent stem cells in a pig model of myocardial infarction: assessment of cell survival, engraftment, and distribution by hybrid single photon emission computed tomography/computed tomography of sodium iodide symporter transgene expression. Circulation 2012; 126 no. 4:430-9. *Authors contributed equally.