Effects of HepII domain peptides V of fibronectin on corneal permeability, endothelial cells, intraocular pressure and morphology of trabecular meshwork in rats.

Background: Trabecular meshwork (TM) cell volume may be an important determinant of aqueous humor outflow in the eye. This study aimed to evaluate the role of HepII domain peptides V on corneal permeability, corneal endothelial cells, intraocular pressure (IOP) and morphology of trabecular meshwork in rats.

Methods: The IOP of rat eyes was measured before and 3, 5, 7 and 8 hours after topical delivery of HepII domain peptides V through intracameral injections. The peptide's concentration in aqueous humor was assessed by high performance liquid chromatography (HPLC). The shape and density of endothelial cells were observed by laser confocal microscopy 8 hours, 3 and 14 days after intracameral injections of HepII domain peptides V. The morphological changes in TM of rat eyes were assessed by transmission electron microscopy (TEM).

Results: Intracameral injection of HepII domain peptides V significantly (P < 0.001) decreased IOP by (5.71 ± 2.10) mmHg in rats at 5 hours after injection. There were no obvious changes of the shape and the density of corneal endothelial cells. In addition, morphological changes in the TM of rats were observed including the expansion of intercellular spaces in the juxtacanalicular meshwork, removal of extracellular material, cellular relaxation, and cytoskeleton reorganization.

Conclusions: HepII domain peptides V could not penetrate cornea and was safe to corneal endothelial cells. HepII domain peptides V could significantly decrease IOP in rat probably by disorganizing actin cytoskeleton and cell-junction in the TM.