Wound healing fibroblasts modulate corneal angiogenic privilege: interplay of basic fibroblast growth factor and matrix metalloproteinases in corneal angiogenesis.

摘要

Corneal angiogenic privilege is an active multicascade process of regulation of blood vessel entry into the cornea.1^1 Research has focused on understanding the mechanisms that maintain corneal avascularity under homeostatic conditions and in avascular wound healing.1'4 Several factors contribute to corneal avascularity, including: (1) expression of antiangiogenic factors in the cornea (including angio-statin, neostatins 7 and 14, and pigment epithelium-derived factor, PEDF);1"6 (2) the balance between angiogenic factors and their soluble receptors in the cornea; (3) mechanical considerations of corneal anatomy (including constant dehydration resulting in tightly packed collagen lamellae and the presence of compact keratocyte networks among thelamellae); (4) the angiostatic nature of corneal epithelial cells; (5) the immune privilege of the cornea and its dependence on the induction of anterior chamber-associated immune deviation in which antigen-specific, delayed-type hypersensitivity is suppressed; and (6) other factors, including lower corneal temperature, extensive innervation, and movement of the aqueous humor across the cornea.