Abstract
Abstract: :
Purpose: The goal of this study is to identify the role of growth factors in corneal wound healing. Nerve Growth Factor (NGF) and the NGF precursor proNGF were studied in vitro and in vivo to reveal their function during corneal regeneration. Methods:Human proNGF and NGF recombinant proteins were produced in E. coli from inclusion body material. ProNGF– and NGF–mediated migration of fibroblast and corneal endothelial cell lines was analysed in the Boyden Chamber assay. NGF or proNGF protein was applied at various concentrations to the lower chamber. The migration of the cells through a 8 µm porous filter was measured after 4 hours incubation in serum–free media. The migration rate was calculated after counting the cells attached to the lower side of the membrane. To analyze the effect of proNGF and NGF in vivo, a rabbit cornea wound model was applied. In a total of 28 rabbits (7 groups, n = 4) corneal wounds of 6 mm in diameter and 300 µm in depth were created with a keratome. The wounds were treated over a period of 7 days 4 times daily with proNGF, NGF (at three doses) or the vehicle solution (0.9 % NaCl). The macroscopic wound healing was monitored daily by digital macrophotographs. Morphometrical evaluation of the corneal ulceration was determined using a morphometry software. Results:Recombinant NGF and proNGF proteins were produced at a purity of about 99 %. In the Boyden Chamber assay proNGF stimulates migration of fibroblasts and corneal endothelial cells significantly and in a dose depend manner. ProNGF displays higher activity compared to mature NGF. The same effect was observed for corneal endothelial cell proliferation in vitro. Detailed data of the in vivo study will be presented revealing the effects of proNGF and NGF on wound healing in the rabbit cornea. Conclusions:Both, the in vitro and in vivo data suggest that proNGF is a good candidate for corneal wound healing.
Keywords: cornea: basic science • growth factors/growth factor receptors • wound healing