角质细胞生长因子2促进兔角膜碱烧伤上皮愈合机制的研究

目的　探讨角质细胞生长因子2 (KGF- 2 )对实验性兔角膜中央碱烧伤后角膜上皮愈合的作用及其机制。方法　24只新西兰白兔的24只角膜碱烧伤眼按随机数字法分成4组,每组6只眼,其中A、B、C组为治疗组,分别以3种不同浓度: 1μg/ml、50μg/ml、100μg/mlKGF 2滴眼液治疗;D组为对照组,用磷酸盐缓冲液(PBS)滴眼液治疗;观察角膜上皮愈合情况,并做形态学检查及P63、角质蛋白单克隆抗体(AE5)、表皮细胞生长因子单克隆抗体(EGFR)免疫组化研究。结果　1 ~100μg/mlKGF 2能够促进兔角膜上皮愈合。角膜碱烧伤24h后100μg/mlKGF- 2组和对照组角膜上皮愈合率分别为40%和74% (P<0 .05);第4天时4组均出现一定反复;第10天时各治疗组近完全愈合。碱烧伤后第7天即可观察到P63阳性细胞不仅存在于角膜缘区的部分基底细胞中,同时也向角膜内迁移。如角膜碱烧伤后第7天角膜缘区P63阳性细胞数: 100μg/mlKGF 2组为( 53 .8±2. 6)个,对照组为(29. 5±2. 2)个,正常角膜为(17. 0±2. 1)个(P=0. 000);同时非角膜缘区P63阳性细胞数分别为: 100μg/mlKGF 2组为(69. 5±2. 8)个,对照组为(19 5±2 8)个,正常角膜为0个(P=0 .000)。结论　KGF- 2可激活角膜上皮干细胞,使其不断增殖分化,从而促进角膜上皮损伤的愈合。

Mechanism of keratinocyte growth factor-2 accelerating corneal epithelial wound healing on rabbit alkali burned cornea

OBJECTIVE: To evaluate the curative effect of KGF-2 on the alkali-injured rabbit eye and to investigate the mechanism of KGF-2 accelerating corneal epithelial wound healing. METHODS: Alkali burn was produced in 24 corneas from 24 New Zealand rabbits. Four groups were randomly divided. Three groups (A, B, and C groups) were treated with KGF-2 solution (1, 50, 100 microg/ml, respectively), and one group (D group) was treated with phosphate-buffered saline (PBS) solution. The injured eyes were photographed after the fluorescence staining with a slit lamp and the pictures were analyzed with computer-aided picture analysis system to calculate the rate of corneal epithelial healing. Morphologic and immunohistological examinations (using P63, AE5 and EGFR antibodies) of the cornea were performed. RESULTS: KGF-2 at dosages ranging from 1 microg/ml to 100 microg/ml could enhance the cornea wound healing process. After 24 hours, epithelial healing rate of the 100 microg/ml KGF-2 group and the PBS treated group was 74% and 40%, respectively (P < 0.05). The corneal epithelial healing rate of each group was variable after four days and achieved complete healing after ten days. The P63 positive cells in KGF-2 groups appeared not only in the limbal area but also in the central area. For example, on the seventh day, in the limbal area, the P63 positive cells in the 100 microg/ml KGF-2 group, the PBS treated group and the normal group were 53.8 +/- 2.6, 29.5 +/- 2.2 and 17.0 +/- 2.1, respectively (P = 0.000). At the same time, the P63 positive cells in the non-limbal area in the 100 microg/ml KGF-2 group, the PBS treated group and the normal group were 69.5 +/- 2.8, 19.5 +/- 2.8 and 0, respectively (P = 0.000). CONCLUSIONS: These results suggested KGF-2 can stimulate the limbal epithelial stem cells to migrate to the central cornea. KGF-2 can accelerate the healing of alkali burned cornea.