Nakamura M, Chikama T, Nishida T
Department of Ophthalmology, Yamaguchi University School of Medicine, Japan.
Biochem Biophys Res Commun. 1998 May 29;246(3):777-82. doi: 10.1006/bbrc.1998.8704.
To clarify the mechanisms by which substance P (SP) and insulin-like growth factor-1 (IGF-1) synergistically facilitate corneal epithelial wound healing, we tested the hypothesis that the combination promotes cell attachment to a fibronectin matrix through up-regulation of expression of integrin alpha 5 beta 1, the major cell surface fibronectin receptor in rabbit corneal epithelial cells. Cultured rabbit corneal epithelial cells were treated with SP and/or IGF-1 and then plated on wells coated with fibronectin and bovine serum albumin. After incubation, the number of cells attached to the wells was counted. In a second experiment, reverse transcription-polymerase chain reaction was used to determine the expression of integrin alpha 5 and beta 1 by cells pretreated with SP and/or IGF-1. The combination of SP and IGF-1 significantly increased the number of cells attached to the fibronectin matrix and the expression of integrin alpha 5. However, attachment to the fibronectin matrix was inhibited by the addition of GRGDSP, a synthetic peptide that mimics fibronectin. Thus, the synergistic enhancing effect of SP and IGF-1 on the attachment of corneal epithelial cells to the fibronectin matrix and on corneal epithelial migration is partly due to the up-regulation of integrin alpha 5 expression in corneal epithelial cells.
为了阐明P物质（SP）和胰岛素样生长因子-1（IGF-1）协同促进角膜上皮伤口愈合的机制，我们检验了以下假设：二者联合通过上调整合素α5β1的表达促进细胞黏附于纤连蛋白基质，整合素α5β1是兔角膜上皮细胞主要的细胞表面纤连蛋白受体。将培养的兔角膜上皮细胞用SP和/或IGF-1处理，然后接种到包被有纤连蛋白和牛血清白蛋白的孔中。孵育后，计数黏附于孔中的细胞数量。在第二个实验中，采用逆转录-聚合酶链反应来测定经SP和/或IGF-1预处理的细胞中整合素α5和β1的表达。SP和IGF-1的联合显著增加了黏附于纤连蛋白基质的细胞数量以及整合素α5的表达。然而，添加模拟纤连蛋白的合成肽GRGDSP可抑制细胞黏附于纤连蛋白基质。因此，SP和IGF-1对角膜上皮细胞黏附于纤连蛋白基质及角膜上皮迁移的协同增强作用部分归因于角膜上皮细胞中整合素α5表达的上调。
