HSV1-tk报告基因显像活体监测骨髓间充质干细胞移植治疗心肌梗死

目的:通过移植转染HSV1-tk报告基因的BMSCs至大鼠心肌梗死模型,探索报告基因显像用于活体监测移植BMSCs治疗心肌梗死的可行性。方法:采用MOI=100的Ad5-HSV1-tk转染BMSCs后,对BMSCs活性和分化能力进行鉴定。结扎大鼠冠状动脉建立心肌梗死模型并鉴定。采用Ad5-HSV1-tk体外转染BMSCs(3×106个细胞),随后移植到大鼠心肌梗死模型的左心室下壁心肌后,采用Micro PET/CT成像(18F-FHBG)进行活体监测移植干细胞。对完成显像研究后的心肌组织进行相关体外分析。结果:采用腺病毒作为载体将HSV1-tk转入BMSCs后,干细胞的形态及流式表面抗原特征没有改变。随后将BMSCs移植到心肌梗死大鼠模型左心室下壁,成功采用18F-FHBG Micro PET/CT显像在心脏移植区域获得了干细胞的特异性影像,大鼠心脏区域18F-FHBG摄取为(0.413±0.128)%ID/g;对照大鼠心脏区域18F-FHBG摄取仅为(0.017±0.003)%ID/g。随后体外分析证实HSV1-tk基因在BMSCs中正确表达。结论:移植在心肌梗死大鼠模型的BMSC可以通过放射性核素显像技术进行在体示踪,HSV1-tk报告基因可以用于活体监测移植干细胞治疗心肌梗死。

Application of HSVI-tk Reporter Gene Imaging to Monitor Stem Cell Transplantation for Treating Myocardial Infarction in vivo

Objective To explore the feasibility of HSV1 -tk reporter gene imaging for monitoring transplanted BMSCs in treatment of myocardial infarction in vivo via transplanting HSVI-tk transfected BMSCs to the heart of rat model with myocardial infarction. Methods BMSCs were transfected with AdS-HSVI-tk （ MOI = 100）, and then the viability and differentiation ca- pability were identified. The myocardial infarction model was established by ligating coronary artery in rats, and then the model was identified, rBMSCs（ 3 × 10^6 cells）were transfected with AdS-HSVI-tk in vitro, and then transplanted into the myocardial cells located left ventricular inferior wall of rat model with myocardial infarction. MicroPET/CT imaging（ is F-FH- BG） were used to monitor the transplanted stem cell in vivo. After the imaging study,the heart tissue was taken out for the other analysis in vitro. Results After rBMSCs were transfected with HSVI-tk by using adenovirus as the vector, the cell morphology under microscope and the characteristics of surface antigen in tlow-cytometry remained, and could be induced and differentiated into osteoblasts. Then the BMSCs were successfully transplanted into the left ventricular inferior wall of a rat model with myocardial infarction. MicroPET/CT imagings were used for the transplanted rBMSCs in rat model and specific imagings of the transplanted stem cell were observed ;for the target region, is F-FHBG uptake were （0.413 ±0. 125 ）% injected dose/g （ % ID/g）. While for the negative control group, is F-FHBG uptake was only （0.017 ±0. 003 ） % ID/g. The later in vitro analysis verified the expression of TGF in BMSCs in the target heart region. Conclusion In rat model of myocardial infarction transplanted BMSCs can be monitored by radionuclide imaging in vivo. HSVI-tk can be used as a reporter gene to monitor transplanted stem cell in treatment of myocardial infarction.