TY - JOUR
T1 - Combined reporter gene PET and iron oxide MRI for monitoring survival and localization of transplanted cells in the rat heart
AU - Higuchi, Takahiro
AU - Anton, Martina
AU - Dumler, Katja
AU - Seidl, Stefan
AU - Pelisek, Jaroslav
AU - Saraste, Antti
AU - Welling, Andrea
AU - Hofmann, Franz
AU - Oostendorp, Robert A.J.
AU - Gansbacher, Bernd
AU - Nekolla, Stephan G.
AU - Bengel, Frank M.
AU - Botnar, Rene M.
AU - Schwaiger, Markus
PY - 2009/7/1
Y1 - 2009/7/1
N2 - There is a need for in vivo monitoring of cell engraftment and survival after cardiac cell transplantation therapy. This study assessed the feasibility and usefulness of combined PET and MRI for monitoring cell engraftment and survival after cell transplantation. Methods: Human endothelial progenitor cells (HEPCs), derived from CD34+ mononuclear cells of umbilical cord blood, were retrovirally transduced with the sodium iodide symporter (NIS) gene for reporter gene imaging by 124I-PET and labeled with iron oxides for visualization by MRI. Imaging and histologic analysis were performed on 3 groups of nude rats on days 1, 3, and 7 after intramyocardial injection of 4 million HEPCs. Results: In vitro studies demonstrated stable expression of functional NIS protein and normal viability of HEPCs after transduction. On day 1, after intramyocardial transplantation, iron- and NIS-labeled HEPCs were visualized successfully on MRI as a regional signal void in the healthy myocardium and on PET as 124I accumulation. The 124I uptake decreased on day 3 and was undetectable on day 7, and the MRI signal remained unchanged throughout the follow-up period. Histologic analysis with CD31 and CD68 antibodies confirmed the presence of either labeled or nonlabeled control transplanted HEPCs at the site of injection on day 1 but not on day 7, when only iron-loaded macrophages were seen. Furthermore, deoxyuride-5′- triphosphate biotin nick end labeling showed extensive apoptosis at the site of transplantation. Conclusion: The combination of MRI and PET allows imaging of localization and survival of transplanted HEPCs together with morphologic information about the heart. Although iron labeling rapidly loses specificity for cell viability because of phagocytosis of iron particles released from dead cells, reporter gene expression provided specific information on the number of surviving cells. This multimodality approach allows complementary analysis of cell localization and viability.
AB - There is a need for in vivo monitoring of cell engraftment and survival after cardiac cell transplantation therapy. This study assessed the feasibility and usefulness of combined PET and MRI for monitoring cell engraftment and survival after cell transplantation. Methods: Human endothelial progenitor cells (HEPCs), derived from CD34+ mononuclear cells of umbilical cord blood, were retrovirally transduced with the sodium iodide symporter (NIS) gene for reporter gene imaging by 124I-PET and labeled with iron oxides for visualization by MRI. Imaging and histologic analysis were performed on 3 groups of nude rats on days 1, 3, and 7 after intramyocardial injection of 4 million HEPCs. Results: In vitro studies demonstrated stable expression of functional NIS protein and normal viability of HEPCs after transduction. On day 1, after intramyocardial transplantation, iron- and NIS-labeled HEPCs were visualized successfully on MRI as a regional signal void in the healthy myocardium and on PET as 124I accumulation. The 124I uptake decreased on day 3 and was undetectable on day 7, and the MRI signal remained unchanged throughout the follow-up period. Histologic analysis with CD31 and CD68 antibodies confirmed the presence of either labeled or nonlabeled control transplanted HEPCs at the site of injection on day 1 but not on day 7, when only iron-loaded macrophages were seen. Furthermore, deoxyuride-5′- triphosphate biotin nick end labeling showed extensive apoptosis at the site of transplantation. Conclusion: The combination of MRI and PET allows imaging of localization and survival of transplanted HEPCs together with morphologic information about the heart. Although iron labeling rapidly loses specificity for cell viability because of phagocytosis of iron particles released from dead cells, reporter gene expression provided specific information on the number of surviving cells. This multimodality approach allows complementary analysis of cell localization and viability.
KW - Cardiology
KW - Cell transplantation
KW - Gene expression imaging
KW - MRI
KW - NIS
KW - PET
UR - http://www.scopus.com/inward/record.url?scp=67650077413&partnerID=8YFLogxK
U2 - 10.2967/jnumed.108.060665
DO - 10.2967/jnumed.108.060665
M3 - Article
C2 - 19525455
AN - SCOPUS:67650077413
SN - 0161-5505
VL - 50
SP - 1088
EP - 1094
JO - Journal of Nuclear Medicine
JF - Journal of Nuclear Medicine
IS - 7
ER -