VEGF和Ang-1在皮肤创伤和放射性烧伤愈合过程中的表达

Study on the expression of vascular endothelial cell growth factor （VEGF） and angiopoietin-1 （Ang-1） during wound healing of the wound and the radiation skin burn

目的研究血管内皮生长因子（VEGF）和促血管生成素-1（Ang-1）在皮肤单纯性创伤和放射性烧伤中表达的动态变化,了解其在血管再生中的作用,为深入探讨放射性烧伤的愈合机制及其治疗提供有意义的实验资料。方法在大鼠背侧切开皮肤全层制备大鼠创伤模型（单创组）,应用电子线照射臀部皮肤,建立放射性烧伤模型（放伤组）。于伤后1-60d不同时间活体伤口取材,HE染色组织病理学观察,应用Western blot法检测VEGF和Ang-1蛋白的表达。结果在单纯性皮肤创伤愈合过程中,VEGF和Ang-1蛋白表达变化均在伤后第1天开始上升,伤后第5-7天达高峰,然后逐渐下降到接近正常水平。在放射性烧伤愈合过程中,VEGF是先降低后升高然后再降低,而Ang-1的变化与此相反。与单创组比较,放烧组VEGF蛋白表达在第1、7和14天明显降低,差异有统计学意义（P〈0.01）;在第1、7、14、21、28和35天Ang-1蛋白表达明显降低,差异有统计学意义（P〈0.01或P〈0.05）,此后渐升高。结论放射性烧伤愈合早期阶段VEGF和Ang-1的蛋白表达明显降低,是放射性烧伤愈合延迟的重要原因之一。

Objective To study the dynamic changes of growth factor（VEGF） and angiopoietin-1 （Ang- 1 ） expression in normal wound and radiation-induced vascular endothelial cell skin burn during wound healing, in order to provide significant experimental data for the further research on the mechanism and therapy of the wound healing caused by radiation, Methods In the full-thickness incision model, we made the wound on the dorsal skin. In the radiation burn model, we irradiated the haunch skin of SD rats were irradiated using electron rays. The specimens were obtained at different time. The pathological changes of the wound tissue were observed with HE staining.The dynamic changes of VEGF and Ang-1 expression in the normal wound and radiation-induced burn were analyzed through Western blot. Results In normal wound model, the changes of the expression of VEGF and Ang-1 protein were substantially coincident. Their expression level began to increase at day 1 after wound, and reached the peak from days 5 to 7 then decreased gradually to the normal level after 7 days. But in radiation skin burn model, the changes of their expression were discrepant. The expression level of VEGF protein was lowered for a long time after irradiation, and it became gradually increased, then decreased. But the changes of Ang-1 protein expression were opposite. Compared with the normal wound model, the expression level of VEGF protein in radiation skin burn model were significantly lowered at days 1,7 and 14 （P 〈 0.01 ）, and the expression lelvel of Ang-1 protein were also significantly decresed at days 1,7, 14, 21,28 and 35 （ P 〈 0.01 or P 〈 0.05） . Conclusions The expression level of VEGF and Ang-1 protein could decrease significantly at early would healing stage of radiation-induced skin burn, and the peak emerged later. These two proteins might not enhance the vasoformation coincidence, so as to delay the wound healing of radiation-induced skin burn.