Bioluminescent monitoring of rat cardiosphere-derived cells in platelet gel engraftment in ischemic heart

Abstract

The success of cell therapy depends on an effective method of cell delivery and engraftment. The use of transgenic cells carrying a reporter system based on the luciferase gene allows to perform the quantitative evaluation of the transplantation efficiency in dynamics using biochemical methods. The purpose of this work was to monitor the persistence of rat cardiosphere-derived cells (CDC) after allogeneic transplantation into the periinfarction zone. Transplantation was performed by intramyocardial injection of a cell suspension in a culture medium or in platelet rich plasma (PRP). When injected into the myocardium PRP forms fibrin clots which serves as a matrix for the transplanted cells. The cells were modified by the luciferase enzyme gene by transduction with lentiviruses (CDC-Luc). The activity of luciferase was determined in protein extracts of the myocardium at different time points after the transplantation. It was shown that in the first hour after injections, CDC-Luc is quantitatively detected in the peri-infarction zone irrespective of the use of platelet gel or medium, and their amount does not decrease within 48 hours. During this period, we found a positive effect of the fibrin matrix on the cells - the luminescence of CDC-Luc protein extracts in the platelet gel composition was significantly higher. We suggested that the platelet gel promotes a more favorable microenvironment for CDC-Luc and facilitates the adaptation of cells after transplantation, what reflected in the recovery of the level of luciferase production in cells. Further, we found negative dynamics: CDC-Luc injected in the culture medium is retained in the myocardium for 5 days and on the seventh day their presence is not determined, CDC-Luc in the fibrin matrix is retained in the myocardium for 10 days after transplantation. Thus, despite the successful transplantation of CDC, the integration of cells into the myocardium does not occur. Nevertheless, the use of platelet gel prolongates the time of CDC persistence in the tissue and enhances of their paracrine effect. The use of fibrin matrix can be useful for long-lived cells, such as cardiomyocytes, in particular, to improve the efficiency of transplantation of the tissue engineering biological pacemaker. A luciferase reportering system can be effective for in vitro and in vivo monitoring of cell fate, both in biotechnological stages of cultivation and assembly of the tissue engineering biopee maker, and after myocardial transplantation. In the future, the developed methodological approach will be used to study of tissue-engineering biopacemakers in experimental animals.