Abstract
Purpose: :
We have previously reported expression of nerve guidance cues (Eph/ephrins) on corneal keratocytes. In these experiments our goal is to determine whether the expression of neurotrophins and nerve guidance proteins changes as the keratocyte transitions between wound healing phenotypes (fibroblast & myofibroblast).
Methods: :
SV-40 immortalized murine corneal fibroblast cell line was established in 10% FCS culture media and characterized. Fibroblast to myofibroblast transformation was achieved using TGF-beta. Neurotrophins (NGF, GDNF, BDNF, CNTF, NT-3, NT4/5), Nerve guidance proteins (EphB1, ephrinb1), vimentin and alpha-smooth muscle actin levels were assayed by quantitative RT-PCR and quantitative Western analyses (LiCor) in fibroblast and myofibroblast cell lines and compared.
Results: :
EphB1/ephrinb1 were differentially expressed. EphB1 expression was decreased in myofibroblasts by 15%, but ephrinb1 was upregulated by 1.7%. Of the neurotrophins BDNF was upregulated in myofibroblasts, but NGF and GDNF were downregulated. Western analysis showed similar trends with ephrinB1 levels increasing by 46% and GDNF decreasing by 25% in myofibroblasts as compared to fibroblasts.
Conclusions: :
Neurotrophins and nerve guidance proteins are differentially expressed in different keratocyte phenotypes. Differential regulation of keratocyte derived neurotrophins and nerve guidance proteins may be of significance in the pathogenesis of neurotrophic keratitis.
Keywords: innervation: neural regulation • cornea: stroma and keratocytes • cornea: basic science