Abstract:

BACKGROUND: When cornea injured, it can induce the phenotypic transition of keratocyte into the fibroblast, which causes the formation of the scar in the stroma and the loss of the vision.
OBJECTIVE: To observe the interaction between the corneal epithelial cell in different regions and the actived keratocyte and to explore that whether the limbal epithelial cell can inhibit the growth of the actived keratocyte.
METHODS: Enzyme digestion and mechanical dissociation were adopted to collect corneal epithelial cells and the keratocyte from central cornea, paramedian cornea, limbus, and then cultured in vitro. The changes of cell morphology and growth were recorded by phase contrast microscopy. The phenotype and proliferation capacity of the cultured cells were identified by immunofluorescent staining with antibodies for p63 and proliferating cell nuclear antigen (PCNA).
RESULTS AND CONCLUSION: When the contact inhibition occured between corneal epithelial cells and fibroblasts, there was a define boundaries to divide them into two sections. In the limbal group, the positively expressing rates in the cultured corneal epithelial cells were higher for PCNA and p63, in the paramedian group the expression of PCNA is also higher and the expression of p63 was negative. In the central group, the expression of PCNA is lower and p63 was negative expression. Only the limbal group has a certain proportion of limbal epithelial stem cells. In limbal group the growth of fibroblasts was inhibited by limbal epithelial cells, after interaction four weeks, fibroblasts were degenerated into dead cell clusters. Because of the limbal stem cells deficiency in central group and paramedian group, the area of fibroblasts was increasing obviously, but the growth of corneal epithelial cells was inhibited and some were displaced by fibroblasts. It is indicated that limbal epithelial cells can inhibit the growth of actived keratocytes and degenerate them in vitro culture.