Blockade of Prolymphangiogenic Vascular Endothelial Growth Factor C in Dry Eye Disease

Abstract

Objective To determine if blocking prolymphangiogenic factors like VEGF-C would suppress alloimmunity in dry eye disease (DED) using a murine model. Methods The effects of intraperitoneal injections of 400 μg of anti-VEGF-C antibody (treated group) and intraperitoneal normal saline (untreated group) were studied in murine dry eyes induced by exposing mice to high-flow desiccated air in the Controlled Environment Chamber (CEC). Growth of lymphatic vessels and infiltration of macrophages was evaluated by immunohistochemistry using CD31 (pan-endothelial marker), LYVE -1(lymphatic endothelial marker) and CD11b (monocytes/macrophages marker). Real time PCR was performed to quantify expression of different inflammatory cytokine transcripts in the conjunctiva and lymph nodes, and vascular endothelial growth factors and their receptors (VEGF-A, C, D/R2, R3) in the cornea. Results Blocking VEGF-C led to significant reduction in lymphatic caliber (P=0.025) and lymphatic area (P=0.006) in the corneas of DED mice. In addition to significantly decreasing (P=0.005) CD11b+ cells, anti-VEGF-C treatment significantly decreased transcript levels of VEGF-C (P=0.002), VEGF-D (P=0.014) and VEGFR-3 (P=0.023) in the corneas of treated group. Significant decrease in expression of inflammatory cytokines in the conjunctiva (IL1-α, P= 0.003; IL1-β, P= 0.025 and IL-6, P= 0.005) and lymph nodes (IFN-γ, P= 0.008; and IL-17, P= 0.003) was also seen with anti-VEGF-C treatment. Conclusions Treatment with anti-VEGF-C led to significant improvement in DED reflected by decrease in inflammation at the clinical, molecular, and cellular levels.