Abstract
Abstract: :
The peptide NC 1059 (developed by NaCelle therapeutics) has been shown to reduce transepithelial resistance in cultured epithelia of different cell lines by altering protein components of tight junctions. Purpose:To study the effect of peptide NC–1059 on corneal permeability to carboxyfluorescein(CF) in rabbit corneas in situ and in vivo and compare the histopathology of corneas treated with the peptide and 0.01% BAC. Methods:Transcorneal permeability(TCP) was evaluated in situ using corneal perfusion blocks. The endothelial side solution had BSS plus. The epithelial side had BSS plus and CF solution .The peptide (40 µM/ml) was added to the epithelial side of the test chamber. 100 µl samples were withdrawn every 30 minutes for 6 hours. The concentrations were measured using a fluorometer .Transepithelial permeability(TEP) was measured in vivo in unanaesthesized rabbits by non–invasive fluorometry. Peptide Solution A( 40 µM/ml in BSS plus) or solution B(80 µM/ml in BSS plus) was exposed to the corneal surface for 3 minutes. The contralateral eye (control) was treated with BSS. After 0 min or 30 min delay, the eyes were exposed to CF for 3 or 5 min and the corneal fluorescence was measured on an ocular fluorometer. The histology of the corneas treated with the peptide, 0.01% BAC and the BSS plus was evaluated using transmission electron microscopy after a ruthenium red(RR) fix. Results:In the in situ experiments (n=7), the Ktrans (cm/sec) for CF was (mean ± SD) 9.72 ± 6.23 * 10–8 with the peptide and 5.13±4.73 * 10–8 with BSS plus representing an average 2.8(range 1.24–4.71) fold increase. There were 3 sets of in vivo experiments. With solution A and CF for 3 min(n=3), the TEP (nm/sec) of the test cornea was 0.07± 0.02 and the control was 0.03±0.01 representing an average 2.14(range1.82– 2.73)times increase. With solution A and CF for 5 min (n=4), the TEP (nm/sec) of the test cornea was 0.29± 0.29 and the control was 0.05±0.03 representing an average 8.00 (range 1.07–18.39 )times increase. With solution B and CF for 5 min(n=5), the TEP(nm/sec) of the test cornea was 0.58± 0.32 and the control was 0.09±0.08 representing an average 15.72(range 2.13–33.02) times increase. The corneas treated with the peptide BAC had RR penetrating paracellularly down to 3–5 epithelial cell layers, the control corneas had no RR penetration.The peptide treated epithelial cells showed a normal morphology and thickness. The BAC treated cells were edematous with an altered morphology. Conclusions:The peptide NC–1059 increases the transcorneal permeability to CF without damaging the epithelium
Keywords: cornea: epithelium • cornea: basic science