大鼠急性β射线皮肤损伤创面愈合过程中基质金属蛋白酶2的表达

The expressions of matrix metalloproteinase-2 in acute β irradiated skin injury in rat

目的研究急性β射线皮肤损伤创面愈合过程中基质金属蛋白酶2(MMP-2)mRNA和蛋白表达的变化,探讨表皮细胞生长因子(EGF)在急性β射线皮肤损伤创面愈合过程中的作用。方法雄性SD大鼠60只,随机均分为3组。A组15Gyβ射线照射组;B组45Gyβ射线照射EGF治疗组;C组45Gyβ射线照射生理盐水对照组。采用直线加速器产生的β射线照射大鼠臀部皮肤,面积20mm×40mm。观察创面出现及愈合的时间;光镜观查创面愈合过程中组织学改变;以RT-PCR法和Westernblot法检测创面愈合过程中MMP-2mRNA和蛋白表达的变化。结果A组未形成创面,B组和C组出现深Ⅱ度烧伤创面。B组创面愈合速度明显比C组快(P<0.05)。A组5、6、8周时MMP-2的表达逐步减弱,B组和C组5、6、8、10周时MMP-2的表达由强到弱,而后由弱到强;B组在6、8周时MMP-2的表达均高于C组。结论EGF在β射线皮肤损伤创面愈合过程中起重要作用,EGF可促进MMP-2的表达与合成,从而促进创面愈合。

Objective To study the expressions of matrix metalloproteinase-2（MMP-2） in acute irradiated skin injury in rat and investigate the effects of epidermal growth factor（EGF） on wound healing. Methods Sixty male SD rats were divided into 3 groups. Group A received- 15Gy in 20 rats, group B 45Gy EGF treating in 20 rats,and group C 45Gy NS as control. The buttock skin（20 mm×40 mm） of rats was irradiated by β radiation produced by the linear accelerator. The wound healing time and rate were observed. The pathological changes were observed by light microscopy. The expressions of MMP-2 were observed with RT-PCR and Western blot method during the would healing of acute irradiated skin injury. Results There was no wound in group A. The deep second degree burn wound was observed in group B and C. The wound healing time of group B was shorter than that of group C. The expression of MMP-2 of group A was weakening gradually from 5 to 8 weeks after irradiation. The expression of MMP-2 of group B and C was from strong to weak and then from weak to strong from 5 to 9 weeks after irradiation. The expression of MMP-2 of group B was higher than that of group C in 6 weeks and 8 weeks. Conclusion The expression of MMP-2 plays an important role during would healing of acute β irradiated skin injury. EGF can promote wound healing by increasing the expression and synthesis of MMP-2.