Abstract
Abstract: :
Purpose:To study the expression of VEGF and its receptor VEGFR-2 in the normal cornea and the changes following a central penetrating alkali burn in the rabbit cornea as well as effects of inhibition of granulocyte (PMN) emigration to the tissue. Methods:A penetrating central corneal alkali wound was inflicted to one eye in each of 14 New Zealand White rabbits (2.5-3 kg). 7 of the rabbits received 1.5 ml 5% fucoidin i.v. every 2 hours for 32 hours. All rabbits were sacrificed after 32 hours. The corneas were excised with a scleral rim, fixed in formalin and embedded in paraffin. Deparaffinated sections were incubated with antibodies against VEGF and VEGFR-2. The section were double-stained with haematoxylin. Results:VEGF: Normal corneal epithelium and endothelium showed low VEGF staining, whereas no staining was detected in keratocytes. The injured corneas expressed VEGF very markedly in the invading cellular fronts of the epithelium, in the keratocytes and the endothelium. Behind this front the expression was similar to the normal cornea. PMNs, that adhered to vessel walls, expressed VEGF strongly, whereas tissue-invading cells stained more variably. Variable staining was observed in the vascular endothelium, but it became more merked following injury and in the presence of PMNs. Fucoidin treatment was not affecting the VEGFR-2: In the normal corneal endothelial and epithelial cells VEGFR-2 was expressed moderately. In injuried corneas expression was marked in the leading edge of the epithelium, in keratocytes and corneal endothelium. The expression peripheral to the leading edge in the epithelium appeared suppressed. The expression in the vascular endothelium as well as in PMNs were weak and varying. Fucoidin treatment was associated with significantly fewer PMNs in the limbus and stroma. Conclusion:The most prominent change in the injured corneas was the expression, in the advacing healing cell fronts, of both VEGF and the receptor suggesting and important role for these growth related molecules in corneal wound healing.
Keywords: 631 wound healing • 423 growth factors/growth factor receptors • 437 inflammation