Yau Terrence M, Li Guangming, Weisel Richard D, Reheman Adili, Jia Zhi-Qiang, Mickle Donald A G, Li Ren-Ke
Division of Cardiothoracic Surgery, Toronto General Hospital, University Health Network, and Department of Surgery, University of Toronto, Ontario, Canada.
J Thorac Cardiovasc Surg. 2004 Apr;127(4):1180-7. doi: 10.1016/j.jtcvs.2003.09.052.
We evaluated the effect of transplanted cell type, time, and region of the heart on transgene expression to determine the potential of combined gene and cell delivery for myocardial repair.
Lewis rats underwent myocardial cryoinjury 3 weeks before transplantation with heart cells (a mixed culture of cardiomyocytes, smooth muscle cells, endothelial cells and fibroblasts, n = 13), vascular endothelial growth factor-transfected heart cells (n = 13), skeletal myoblasts (n = 13), vascular endothelial growth factor-transfected skeletal myoblasts (n = 13), or medium (control, n = 12). Vascular endothelial growth factor expression in the scar, border zone, and normal myocardium was evaluated at 3 days and at 1, 2, and 4 weeks by means of quantitative polymerase chain reaction. Transplanted cells and vascular endothelial growth factor protein were identified immunohistologically on myocardial sections.
Vascular endothelial growth factor levels were very low in control scars but increased transiently after medium injection. Transplantation with heart cells and skeletal myoblasts significantly increased vascular endothelial growth factor expression in the scar and border zone. Transplantation of vascular endothelial growth factor-transfected heart cells and vascular endothelial growth factor-transfected skeletal myoblasts further augmented vascular endothelial growth factor expression, resulting in 4- to 5-fold greater expression of vascular endothelial growth factor in the scar at 1 week. Peak vascular endothelial growth factor expression was greater and earlier in vascular endothelial growth factor-transfected heart cells than in vascular endothelial growth factor-transfected skeletal myoblasts. Vascular endothelial growth factor was primarily expressed by the transplanted cells. Some of the transplanted heart cells and vascular endothelial growth factor-transfected heart cells were identified in the endothelial layer of blood vessels in the scar.
Transplantation of heart cells and skeletal myoblasts induces vascular endothelial growth factor expression in myocardial scars and is greatly augmented by prior transfection with a vascular endothelial growth factor transgene. Vascular endothelial growth factor expression is limited to the scar and border zone for 4 weeks. Both heart cells and skeletal myoblasts may be excellent delivery vehicles for cell-based myocardial gene therapy.
我们评估了移植细胞类型、时间以及心脏区域对转基因表达的影响，以确定基因与细胞联合递送用于心肌修复的潜力。
Lewis大鼠在移植前3周接受心肌冷冻损伤，然后分别移植心脏细胞（心肌细胞、平滑肌细胞、内皮细胞和成纤维细胞的混合培养物，n = 13）、血管内皮生长因子转染的心脏细胞（n = 13）、骨骼肌成肌细胞（n = 13）、血管内皮生长因子转染的骨骼肌成肌细胞（n = 13）或培养基（对照，n = 12）。在3天以及1、2和4周时，通过定量聚合酶链反应评估瘢痕、边缘区和正常心肌中血管内皮生长因子的表达。在心肌切片上通过免疫组织学方法鉴定移植细胞和血管内皮生长因子蛋白。
对照瘢痕中的血管内皮生长因子水平非常低，但在注射培养基后短暂升高。移植心脏细胞和骨骼肌成肌细胞可显著增加瘢痕和边缘区中血管内皮生长因子的表达。血管内皮生长因子转染的心脏细胞和血管内皮生长因子转染的骨骼肌成肌细胞的移植进一步增强了血管内皮生长因子的表达，导致1周时瘢痕中血管内皮生长因子的表达增加4至5倍。血管内皮生长因子转染的心脏细胞中血管内皮生长因子的峰值表达比血管内皮生长因子转染的骨骼肌成肌细胞更大且更早。血管内皮生长因子主要由移植细胞表达。在瘢痕血管的内皮层中鉴定出了一些移植的心脏细胞和血管内皮生长因子转染的心脏细胞。
心脏细胞和骨骼肌成肌细胞的移植可诱导心肌瘢痕中血管内皮生长因子的表达，并且通过预先用血管内皮生长因子转基因转染可大大增强该表达。血管内皮生长因子的表达在4周内仅限于瘢痕和边缘区。心脏细胞和骨骼肌成肌细胞都可能是基于细胞的心肌基因治疗的优良递送载体。
