Shuo Shi, Min Zhang, Rui Guo, Ying Miao, Xiangming Zhang and Biao Li Pages 460 - 471 ( 12 )
Heart tissue has a diminished ability to repair after myocardial infarction (MI). Bone marrow- derived mesenchymal stem cells (BMSCs) have been used effectively to heal damaged tissue after MI. Hypoxia-inducible factor-1α (HIF-1α) can induce transcription of numerous pro-angiogenic genes and enhance stem cell survival. Here, we investigated whether HIF-1α-transduced BMSCs could enhance tissue repair after MI, and compared the value of micro-PET/CT and echocardiography for evaluation of therapeutic effects. Rat BMSCs were transduced with a lentivirus expressing HIF-1α and NIS (Lenti-HIF-1α-NIS). Sodium iodide symporter (NIS) functioned as effective reporter gene, allowing monitoring of BMSCs transplanted into the rat heart for up to 2 weeks using micro-SPECT/CT imaging. In a rat MI model, after transplantation of HIF-1α-NIS-transduced BMSCs to the MI zone, more expression of HIF-1α,VEGF and Ang-4, more improvement of metabolism, less fibrotic tissue and cardiomyocyte apoptosis were detected in the MI zone. Moreover, we found that most of the transplanted HIF-1α-NIS-transduced BMSCs differentiated into endothelial cells, and engineered new blood vessels in MI zone. Metabolic activity significantly increased at an early time point (2 weeks after transplantation) and lead to a sustained increase (4 weeks), as indicated by 18F-FDG uptake in micro-PET/CT imaging. Echocardiography indicated no improvement in cardiac function at 2 weeks and small improvement at 4 weeks. This study indicated that 18F-FDG micro-PET/CT was more useful for evaluating early therapeutic effects than echocardiography.
Cell therapy, Gene therapy, Molecular imaging, Myocardial infarction.
Department of Nuclear Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197, Ruijin Er Rd, Shanghai 200025, China.