自体骨髓单个核细胞植入心肌梗死及其周边区促进血管生成相关基因表达的研究

Upregulating Angiogenesis-promoting Genes by Transplanting Autologous Mononuclear Bone Marrow Cells into Myocardial Infarction Scar and The Periphery

目的 :探讨骨髓单个核细胞植入心肌梗死及其周边区对心肌梗死的治疗作用 ,促进血管新生及相关基因表达情况。方法 :以冷冻损伤的方法建立新西兰种家兔心梗模型 ,4周后 ,将提取分离的骨髓单个核细胞 ,植入心梗及心梗周边区。分析心梗及心梗周边区病理组织学特点 ,比较区域内微血管密度 ,并以Westernblot研究骨髓单个核细胞移植对心梗及心梗周边区血管生成相关基因表达的影响。结果 :(1)骨髓单个核细胞植入心梗及心梗周边区减少移植区域瘢痕化 ,增加微血管密度 ;(2 )骨髓单个核细胞植入心梗及心梗周边区使某些重要血管生成相关基因 ,VEGF ,FGF及Angiopoietin -Ⅰ表达上调 ,于心梗周边区作用更加显著。结论 :骨髓单个核细胞植入心梗及心梗周边区可以减少移植区域瘢痕化 ,增加微血管密度 ,上调心梗及心梗周边区重要血管生成相关基因。

Objective: Our study was designed to test the therapeutic effectiveness of transplanting mononuclear bone marrow cells into myocardial infarction scar and the periphery, and detect the expression of important angiogenic genes involved in the processes of collateral development. Methods: Myocardial infarction scar was induced by cryoinjury. After 4 weeks, twenty-four hours before cell transplantation, bone marrow was aspirated from the right thigh bone and mononuclear BMCs were isolated by Ficoll desity gradient centrifugation. Then the mononuclear BMCs(n=8) or IMDM culture medium(n=8) were transplanted into infarction scar and the periphery. Four weeks after cell transplantation, histological study was performed to assess the characteristics and compare the number of microvessels of the samples of infarction scar and the periphery in both groups, and compare the differences of angiogenic genes expression among several important growth factors by western blot. Results: In the mononuclear BMCs transplantation group, the microvessel densities were (8.56±1.32)/0.2mm 2 and (12.449±1.97)/ 0.2 mm 2 in the infarction scar and the periphery, respectively, which were significantly higher than those in the control group, ie, (4.92±1.61)/0.2mm 2 (P<0.05) and (6.84±2.18)/0.2mm 2 (P<0.05), respectively. Western blot analysis demonstrated that mononuclear BMCs transplantation was capable to increase the levels of VEGF, FGF and Agiopoietin-Ⅰexpression in the infarction scar and the periphery, respectively, compared with those in the control group (P<0.05). Conclusion:The expression of some important angiogenesis-promoting genes regulated in relatively high levels in infarction scar and the periphery after mononuclear BMCs transplantation. Furthermore, in the periphery of infarction scar, the angiogenesis process induced by mononuclear BMCs is more effective. These findings imply that transplantation of total, unfractionated bone marrow is appealing because of its apparent simplicity and therapeutic effectiveness in upregulating the expression of important angiogenesis-promoting genes.