兔耳慢性缺血性溃疡愈合过程中增殖细胞核抗原、半胱氨酸天冬氨酸蛋白酶3和c-myc的表达

Expression of proliferating cell nuclear antigen, caspase-3 and c-myc in the healing of chronic ischemic ulcer in rabbits’ears

目的:观察兔耳慢性缺血性溃疡愈合过程中增殖细胞核抗原、半胱氨酸天冬氨酸蛋白酶3和c-myc的表达变化,了解增殖与凋亡活动对慢性缺血性创面愈合的作用。方法:实验于2003-10/2004-10在昆明医学院第二临床学院中心实验室完成。选用健康日本纯种大耳白兔23只,对照组2只,为无缺血兔耳正常皮肤;实验组21只,建立慢性缺血性兔耳溃疡模型。采用兔耳慢性缺血性溃疡模型,设立伤后1,4,7,11,15,22和26d组,用SP免疫组织化学方法研究创面组织中增殖细胞核抗原、半胱氨酸天冬氨酸蛋白酶3和c-myc蛋白的表达规律和分布特征。结果:实验兔23只均进入结果分析。①创面愈合过程中增殖细胞核抗原、半胱氨酸天冬氨酸蛋白酶3和c-myc蛋白的表达增高,并具有一定的时相性。②正常兔耳皮肤组织中有少量的增殖细胞核抗原、半胱氨酸天冬氨酸蛋白酶3和c-myc蛋白的表达。③伤后15d,增殖细胞核抗原、半胱氨酸天冬氨酸蛋白酶3和c-myc蛋白的表达最高,随后逐渐下降,主要分布在成纤维细胞的胞浆和胞核。结论:创面慢性缺血性溃疡愈合过程中增殖细胞核抗原、半胱氨酸天冬氨酸蛋白酶3和c-myc蛋白的表达升高,其表达具有时相特征性和特定的表达部位,三者表达的时相提示半胱氨酸天冬氨酸蛋白酶3和c-myc参与调控慢性缺血性溃疡愈合过程,细胞增殖活动与细胞凋亡的规律基本一致。适量调控半胱氨酸天冬氨酸蛋白酶3和c-myc的表达水平,可能促进创面愈合。

AIM： To observe the changes in the expressions of proliferating cell nuclear antigen（PCNA）, caspase-3 and c-myc so as to study the effect of proliferation and apoptosis on the healing of chronic ischemic wound. METHODS： The experiment was conducted in the Central Laboratory of the Second Clinical College of Kunming Medical College from October 2003 to October 2004. Twenty-three healthy Japanese flap-eared white rabbits were selected and divided into two groups： two rabbits in control group with non-iscbemic ear skin and 21 in experimental group with chronic ischemic ulcer in ear. After establishment of chronic ischemic ulcer model of ear in rabbits, the experimental group were subdivided into 1-, 4-, 7-, 11-, 15-, 22-, and 26-day post-injury groups. SP immunohistochemical method was used to study the expression regularity and distributing characteristics of PCNA, caspase-3 and c-myc protein. RESULTS： All the 23 rabbits were involved in the result analysis. ①During the wound healing, expressions of PCNA, caspase-3 and c-myc protein were increased in a time-phase manner. ②There were few expressions of PCNA, caspase-3 and c-myc protein in normal ear skin of rabbits. ③Fifteen days after injury, expressions of PCNA, caspase-3 and c-myc protein reached the peak, then decreased gradually, and mainly distributed in cytoplasm and nuclei of fibroblasts. CONCLUSION： In the wound healing of chronic ischemic ulcer, expressions of PCNA, caspase-3 and c-myc protein are increased in a tlme-phase manner and in definite sits. The expressions in a time-phase manner indicate that caspase-3 and c-myc are involved in the regulation of the healing of chronic ischemic ulcer, and the rule of cell proliferation is basically similar to that of cell apoptosis. Proper regulation of caspase-3 and c-myc expression may facilitate wound healing.