Abstract
Purpose: :
Lymphatic dysfunction is associated with a wide array of disorders from transplant rejection to cancer metastasis. To date, there is little effective treatment for lymphatic diseases. The cornea provides an ideal tissue for lymphatic research due to its unique features. We have recently provided the first evidence showing that lymphatic valves are formed during corneal inflammatory lymphangiogenesis (LG) via the up-regulation of integrin alpha 9 (Truong et al. 2011). These structures play a critical role in directing proper lymph flow within the vessels. The purpose of this study is to further characterize the time course of valve formation and subsequent regression during corneal inflammatory LG. The distribution of these valves in the nasal and temporal side was also compared.
Methods: :
Our standardized suture-induced corneal inflammatory LG murine model was used. Whole-mount corneas were harvested between 2 and 8 weeks post-suture for immunofluorescent microscopic analysis. Digital images were analyzed by NIH Image J software to quantify valve distribution in whole cornea as well as the nasal and temporal sides.
Results: :
The number of corneal lymphatic valves after suture placement peaked around 2 to 4 weeks. At 8 weeks post-suture, there was a noticeable decrease. Furthermore, our data demonstrated that lymphatic valves were more distributed in the nasal compared to the temporal aspect of the cornea during inflammation.
Conclusions: :
This study presents a new insight for evaluating corneal LG via the presence and/or absence of lymphatic valves during inflammatory processes. Since lymphatic valves are closely associated with vessel function, this study also offers a novel model for future investigation of lymphatic valve formation and therapeutic intervention for lymphatic related diseases.
Keywords: cornea: basic science • neovascularization • inflammation