P 233Detection of neurotrophic growth factors in the cornea
S. Ebner, L. You, B. Sinn, F. E. Kruse
A clinical trial and laboratory research have shown, that nerve growth factors have a special significance for the regeneration of the surface of the cornea. Nerve growth factor (NGF) has been used for treatment of corneal ulcers. We investigated whether nerve growth factors and their receptors are exprimated by cornea epithelial and stroma cells, and we began to explore the signal transduction.
Methods: Nerve growth factors and their receptors were detected in cultured and native cornea epithelial and stroma cells by PCR and dot blots. Recombinant protein for NGF and GDNF was used in proliferation assays. Signal transduction was investigated via antibodies against phosphorylated kinases by western blot.
Results: Transcription of NGF, NT-3, BDNF and receptors TrK-A, B, C and D was detected in cornea epithelial and stroma cells. The transcription of NT-4 could only be detected in the epithelium, that of GDNF only in the stroma. In culture NGF and GDNF stimulated the proliferation of corneal epithelial cells. In addition we have observed the phosphorylation of MAP-kinase and focal adhesion-kinase.
Discussion: We have demonstrated, that nerve growth factors are not only expressed by nerve tissue, but also by resident corneal cells. These proteins are involved in the regulation of cell proliferation. Their effect is mediated by the MAP-kinase signal transduction pathway.
Augenklinik der Universität Heidelberg, INF 400, D-69120 Heidelberg