Nishida T, Nakamura M, Mishima H, Otori T
Department of Ophthalmology, Kinki University School of Medicine, Osaka, Japan.
J Cell Physiol. 1990 Dec;145(3):549-54. doi: 10.1002/jcp.1041450323.
In order to clarify the roles of fibronectin (FN) and epidermal growth factor (EGF) in corneal wound healing, we cultured blocks of excised rabbit cornea for 24 hours in media containing one of these agents, then measured the length of the path of the epithelial layer that had migrated down the side of the block. Both FN and EGF stimulated epithelial migration significantly in a dose-dependent fashion. Responses to EGF involved a time lag of at least 12 hours before stimulation could be observed, but there was no lag-time for FN-stimulated migration. FN was maximally effective only if it was continuously present. In contrast, exposure to EGF for 6 hours did not stimulate epithelial migration, but exposure for 9 hours resulted in the same stimulatory effects as were observed after 24 hours' continuous exposure. Anti-FN antibody inhibited the FN- and EGF-stimulated migration of corneal epithelium. But anti-EGF antibody inhibited only EGF-stimulated migration and had no effect on FN-stimulated migration. These results indicate that, unlike FN, EGF need not be present, once the epithelial cells have recognized its signal. Furthermore, the stimulatory effect of EGF depended on FN, while that of FN was independent of EGF. The effects of EGF on migration of corneal epithelium may, therefore, be mediated by FN.
为了阐明纤连蛋白（FN）和表皮生长因子（EGF）在角膜伤口愈合中的作用，我们将切除的兔角膜块在含有其中一种因子的培养基中培养24小时，然后测量迁移到角膜块侧面的上皮层的迁移路径长度。FN和EGF均以剂量依赖方式显著刺激上皮迁移。对EGF的反应在观察到刺激之前至少有12小时的时间滞后，但FN刺激的迁移没有滞后时间。只有当FN持续存在时才具有最大效果。相比之下，暴露于EGF 6小时未刺激上皮迁移，但暴露9小时产生的刺激效果与24小时持续暴露后观察到的相同。抗FN抗体抑制FN和EGF刺激的角膜上皮迁移。但抗EGF抗体仅抑制EGF刺激的迁移，对FN刺激的迁移无影响。这些结果表明，与FN不同，一旦上皮细胞识别了EGF的信号，EGF不必持续存在。此外，EGF的刺激作用依赖于FN，而FN的刺激作用不依赖于EGF。因此，EGF对角膜上皮迁移的作用可能是由FN介导的。
