title: An experimental study on use of 7T MRI for evaluation of myocardial infarction in SD rats transfected with pcDNA 3.1(+)/VEGF121 plasmid.
abstract: This study aims to build the myocardial infarction model in SD rats transfected with pcDNA 3.1(+)/VEGF121 plasmid and study the effect of the transfection using 7T MRI. Twenty-four male SD rats were randomly divided into 2 groups, pcDNA 3.1(+)/VEGF121 plasmid transfection group (with improved coronary perfusion delivery) and myocardial infarction model group. Cardiac cine magnetic resonance imaging (Cine-MRI), T2-mapping and late gadolinium enhancement (LGE) cardiac imaging were performed at 24 h, 48 h, 72 h and 7 d after myocardial infarction, respectively. The signal intensity, area at risk (AAR), myocardium infarction core (MIC) and salvageable myocardial zone (SMZ) were compared. The hearts were harvested for anatomic characterization, which was related to pathological examination (TTC staining, HE staining, Masson staining and immunohistochemical staining). The Cine-MRI results showed that pcDNA 3.1(+)/VEGF121 plasmid transfection group had higher end-diastolic volume (EDV) with a reduction in MIC and SMZ, as compared with the myocardial infarction model group. MIC, SMZ and AAR of the plasmid transfection declined over time. At 7 d, the two groups did not differ significantly in AAR and T2 value. According to Western Blotting, VEGF was up-regulated, while CaSR and caspase-3 were downregulated in the plasmid transfection group, as compared with the model group. In conclusion, a good treatment effect was achieved by coronary perfusion of pcDNA 3.1(+)/VEGF121 plasmid. 7T CMR sequences provide a non-invasive quantification of the treatment efficacy. However, the assessment of myocardial injury using T2 value and AAR in the presence of edema is less accurate. The myocardial protection of the plasmid transfection group may be related to the inhibition of myocardial apoptosis, vascular endothelial cell (VEC) proliferation and collagen proliferation. The CaSR signaling pathway may contribute to reversing the apoptosis.
authors.affiliation: Department of Radiology General Hospital of PLABeijing 100853, PR China; Department of Radiology, Affiliated Hospital of Guizhou Medical UniversityGuiyang, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Oncology, The First People's Hospital of Guiyang PR China.
authors.forename: Ruiqing
authors.initials: R
authors.lastname: Tian
authors.affiliation: The Key Laboratory of Optional Utilization of Natural Medical Resource, Guizhou Medical University University Town, Guian New District, Guiyang, PR China.
authors.forename: Xiangchun
authors.initials: X
authors.lastname: Shen
authors.affiliation: Molecular Imaging Laboratory, Department of Radiology, West China Hospital, Sichuan University PR China.
authors.forename: Yushu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Molecular Imaging Laboratory, Department of Radiology, West China Hospital, Sichuan University PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Radiology General Hospital of PLA Beijing 100853, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Gan
authors.affiliation: Department of Radiology, Affiliated Hospital of Guizhou Medical University Guiyang, PR China.
authors.forename: Guiquan
authors.initials: G
authors.lastname: Shen
authors.affiliation: Department of Radiology General Hospital of PLA Beijing 100853, PR China.
authors.forename: Haiyue
authors.initials: H
authors.lastname: Ju
authors.affiliation: Department of Radiology General Hospital of PLA Beijing 100853, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.affiliation: Molecular Imaging Laboratory, Department of Radiology, West China Hospital, Sichuan University PR China.
authors.forename: Fabao
authors.initials: F
authors.lastname: Gao
keywords: CaSR; Gene therapy; myocardial infarction; salvageable myocardial zone