Different expression of angiogenesis-related factors between human cultivated corneal and oral epithelial sheets

Abstract

We developed a cultivated oral mucosal epithelial sheet (COE) transplantation system to address severe human ocular surface disorders. Unlike the cultivated corneal epithelial sheet (CCE), the COE induces mild superficial peripheral neovascularization although central clarity is maintained. To evaluate the characteristic differences between CCE and COE regarding to angiogenesis, we examined the expression of angiogenesis-related factors in CCE and COE. Using samples of CCE and COE, we immunohistochemically determined protein expression of the angiogenesis related factors: Thrombospondin-1 (TSP-1), pigment epithelium derived factor (PEDF), endostatin, angiostatin, vascular endothelial growth factor (VEGF), Fms-like tyrosine kinase 1 (Flt-1), kinase insert domain receptor (KDR), and basic fibroblast growth factor (bFGF). We used Western blot analysis to confirm the factors that were immunohistochemically different in CCE and COE. The immunohistochemical staining intensity of TSP-1 was higher in CCE than COE and by Western blot analysis the expression of TSP-1 was significantly higher in CCE than COE ( P < 0.05). PEDF and endostatin stained moderately stronger in CCE than COE. Immunohistochemically there was no obvious difference between CCE and COE with respect to angiostatin, VEGF, Flt-1, KDR, and bFGF. In comparison with CCE, COE showed decreased expression of anti-angiogenic factors particularly TSP-1. This different expression may relate to the superficial peripheral neovascularization encountered after COE transplantation.