The Role of Bovine Lactoferrin and Bovine Lactoferricin in the Ocular Angiogenesis

Abstract

Purpose: : To determine the ability of bovine lactoferrin (bLF) and lactoferricin (LfcinB) to prevent experimentally induced neovascularization in C57BL/6J mice using two models: model 1- the laser induced choroidal neovascularization (CNV) and model 2- the cornea micropocket assay model. LF was administered either intraperitoneally (IP) or intravitreally (ITV) and LfcinB was administered through a cornea pellet.

Methods: : Model 1: four 532-nm argon laser spots (100 mW, 100 msec, 100 µm) were placed between the retinal vessels in each eye. The first group (7 eyes) received 200ug/ml ITV bLF at the time of the laser and the second group (10 eyes) received IP bLF at 100 mg/kg/day for 10 days. Control animals received sterile saline ITV or IP (6 and 7 eyes respectively). At day 11, the animals were perfused with fluorescein labeled Tomato lectin and sacrificed. The CNV surface area and volume were measured by confocal microscopy of the RPE/choroid/scleral flatmount preparation. Model 2: Two slow-release pellets containing bFGF (50-ng/ml concentration) and LfcinB (50-mg/ml concentration), were placed into the same corneal micropocket in 10 eyes, 1 and 0.8 mm from the limbus respectively. As a control, albumin replaced LfcinB. At day 8, the animals were sacrificed and the area of neovascularization measured by immunohistochemistry with CD31 and LYVE-1 antibodies for blood and lymphatic vessels respectively.

Results: : model 1: bLF administered at dose of 100 mg/kg IP, every day for 10 days or 200ug/ml ITV single dose, reduced the volume of the CNV by 40% (p= 0.07 ITV; P= 0.01 IP groups) and showed a trend for reduction in the surface area by 20% (p=0.17 ITV; p= 0.16 IP groups). Model 2: LfcinB pellet at 50-mg/ml concentration reduced the area of corneal neovascularization by 45% (p=0.01).

Conclusions: : bLF and LfcinB, appear to have a potent antiangiogenic effect in two animal models of neovascularization. To our knowledge this is the first demonstration of the ocular antiangiogenic properties of these endogenous proteins, and supports further research to assess their utility for clinical applications.

Keywords: choroid: neovascularization • cornea: basic science • vascular endothelial growth factor