Abstract
Purpose: :
To determine the ability of bovine lactoferrin (bLF) to prevent experimentally induced vascular leakage and inflammation in the Lipopolysaccharide (LPS) induced uveitis murine model. Vascular permeability was assessed by the biotinylated bovine albumin assay (bBSA). Expression of the proinflammatory mediators: Interleukin-6 (IL-6), monocyte chemotactic protein 1 (MCP-1) and Tumor Necrosis Factor- a (TNF-a) were assessed by qRT-PCR.
Methods: :
Intravitreal (ITV) LPS was used to induce vascular leakage and inflammation in C57BL/6J mice. Group 1, received ITV LPS 1 microgram (ug) in 1.5 microliters (ul) (4 eyes). Group 2, the treatment group (bLF+LPS), received ITV 1.5 ul containing 33 ug bLF and 1 ug LPS (4 eyes). Group 3, control group received ITV 1.5 ul of Phosphate buffered saline (4 eyes). Analysis of the vascular permeability: Twenty hours after the ITV injections, 50 uL of 30 mg/ml bBSA was administered intravenously. The animals were perfused with lactate’s Ringer, sacrificed and the retinas isolated. The retinal vascular permeability was measured by Sandwich ELISA technique of the bBSA levels and expressed as nanoliters (nl) of plasma /milligrams (mg) of retinal protein /hour (hr), by spectrometry. In a second set of experiments twelve hours after the same ITV injections, analysis of IL-6, MCP-1 and TNF-a expression was performed by qRT-PCR in group 1 (10 eyes), group 2 (6 eyes) and group 3 (6 eyes).
Results: :
Twenty hours after injections, the mean ± S.D. of the retinal vascular permeability was 56+/- 7.5 for the control group and increased to 269+/- 80 nl/mg/hr with LPS in group 1. Administration of bLF reduced the LPS leakage levels to 71 +/- 29.6 (group 2). Twelve hours after injections, mRNA levels of IL6 and MCP-1 were elevated in the LPS group, when compared to control by 4.5 and 3.5 fold respectively (P=0.012 and p= 0.002). The mRNA levels of IL6 and MCP-1 were elevated in the LPS group when compared to bLF+LPS treated group by 4.0 and 2.2 fold respectively (p=0.014 and p=0.01). Thus, bLF treatment prevented this increase.
Conclusions: :
bLF, appears to prevent experimentally induced vascular leakage and inflammation in the LPS murine model for uveitis. To our knowledge this is the first ocular basic research demonstrating the intraocular anti-inflammatory properties of this natural protein.
Keywords: uveitis-clinical/animal model • inflammation • injection