β-神经生长因子转染的大鼠内皮祖细胞分化功能的变化

The influence of human β-nerve growth factor on the differenciation capacity of rat endothelial progenitor cells

目的探讨β-神经生长因子(β-NGF)转染的大鼠内皮祖细胞分化功能的变化。方法将人β-NGF重组腺病毒(Ad-EGFP-hβ-NGF组)及其阴性对照(Ad-EGFP组)感染至大鼠内皮祖细胞,同时设置空白对照(NC)组,观察细胞形态学改变,Western blot检测不同组酪氨酸蛋白激酶A(TrkA)表达水平,ELISA法检测不同组培养液中血管内皮生长因子(VEGF)、血管性血友病因子(vWF)及碱性成纤维生长因子(bFGF)水平。结果 Ad-EGFP-hβ-NGF感染至大鼠内皮祖细胞1周后可见部分细胞成球,呈干细胞样改变。Ad-EGFP-hβ-NGF组内皮祖细胞TrKA相对蛋白表达水平(0.67±0.23)明显高于Ad-EGFP组(0.20±0.07)及NC组(0.27±0.12)(P<0.01)。Ad-EGFP-hβ-NGF组培养液中VEGF、vWF及bFGF水平明显高于Ad-EGFP组及NC组(P<0.01)。结论β-NGF通过激活酪氨酸激酶信号通路,增加促血管生长因子的分泌,促进内皮祖细胞的分化,多途径发挥血管修复和再生的功能。

Objective To evaluate the influence of β-nerve growth factor （β-NGF） on the differentiation of endothelial progenitor cells （EPCs）. Methods Primary rat EPCs were isolated from rat bone marrow. The purified EPCs were divided into three groups, and they were transfected with human β- NGF adenovirus （Ad-EGFP-hβ-NGF） and its control （AcI-EGFP） respectively, an addition pseudo- transfection was acted as blank control. 48 hours after transfection, we observed and compared their morphological changes. The TrkA expression was determined by Western blot, and we further detected the secretion of VEGF, vWF and bFGF in EPCs by ELISA. Results We found that EPCs were originally identified as fibroblastic appearance and then appeared to be epithelial-like. Ad-EGFP-hβ-NGF transfection induced EPCs to show a sphere-like growth, to up-regulate its expression of TrkA （P〈0. 01）, and to enhance the secretion of VEGF, vWF and bFGF （P〈0.01） significantly as compared to the blank and Ad- EGFP groups. Conclusion β-NGF activates TrkA signaling pathway, and up-regulates its secretion of VEGF, vWF and bFGF, which facilitate the differentiation of EPCs and contribute to angiopoiesis or vascular repair.